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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/tty/serial/amba-pl011.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/tty/serial/amba-pl011.c')
-rw-r--r--drivers/tty/serial/amba-pl011.c3016
1 files changed, 3016 insertions, 0 deletions
diff --git a/drivers/tty/serial/amba-pl011.c b/drivers/tty/serial/amba-pl011.c
new file mode 100644
index 000000000..c74eaf255
--- /dev/null
+++ b/drivers/tty/serial/amba-pl011.c
@@ -0,0 +1,3016 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Driver for AMBA serial ports
+ *
+ * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ * Copyright 1999 ARM Limited
+ * Copyright (C) 2000 Deep Blue Solutions Ltd.
+ * Copyright (C) 2010 ST-Ericsson SA
+ *
+ * This is a generic driver for ARM AMBA-type serial ports. They
+ * have a lot of 16550-like features, but are not register compatible.
+ * Note that although they do have CTS, DCD and DSR inputs, they do
+ * not have an RI input, nor do they have DTR or RTS outputs. If
+ * required, these have to be supplied via some other means (eg, GPIO)
+ * and hooked into this driver.
+ */
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/device.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/amba/bus.h>
+#include <linux/amba/serial.h>
+#include <linux/clk.h>
+#include <linux/slab.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/scatterlist.h>
+#include <linux/delay.h>
+#include <linux/types.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/sizes.h>
+#include <linux/io.h>
+#include <linux/acpi.h>
+
+#define UART_NR 14
+
+#define SERIAL_AMBA_MAJOR 204
+#define SERIAL_AMBA_MINOR 64
+#define SERIAL_AMBA_NR UART_NR
+
+#define AMBA_ISR_PASS_LIMIT 256
+
+#define UART_DR_ERROR (UART011_DR_OE|UART011_DR_BE|UART011_DR_PE|UART011_DR_FE)
+#define UART_DUMMY_DR_RX (1 << 16)
+
+enum {
+ REG_DR,
+ REG_ST_DMAWM,
+ REG_ST_TIMEOUT,
+ REG_FR,
+ REG_LCRH_RX,
+ REG_LCRH_TX,
+ REG_IBRD,
+ REG_FBRD,
+ REG_CR,
+ REG_IFLS,
+ REG_IMSC,
+ REG_RIS,
+ REG_MIS,
+ REG_ICR,
+ REG_DMACR,
+ REG_ST_XFCR,
+ REG_ST_XON1,
+ REG_ST_XON2,
+ REG_ST_XOFF1,
+ REG_ST_XOFF2,
+ REG_ST_ITCR,
+ REG_ST_ITIP,
+ REG_ST_ABCR,
+ REG_ST_ABIMSC,
+
+ /* The size of the array - must be last */
+ REG_ARRAY_SIZE,
+};
+
+static u16 pl011_std_offsets[REG_ARRAY_SIZE] = {
+ [REG_DR] = UART01x_DR,
+ [REG_FR] = UART01x_FR,
+ [REG_LCRH_RX] = UART011_LCRH,
+ [REG_LCRH_TX] = UART011_LCRH,
+ [REG_IBRD] = UART011_IBRD,
+ [REG_FBRD] = UART011_FBRD,
+ [REG_CR] = UART011_CR,
+ [REG_IFLS] = UART011_IFLS,
+ [REG_IMSC] = UART011_IMSC,
+ [REG_RIS] = UART011_RIS,
+ [REG_MIS] = UART011_MIS,
+ [REG_ICR] = UART011_ICR,
+ [REG_DMACR] = UART011_DMACR,
+};
+
+/* There is by now at least one vendor with differing details, so handle it */
+struct vendor_data {
+ const u16 *reg_offset;
+ unsigned int ifls;
+ unsigned int fr_busy;
+ unsigned int fr_dsr;
+ unsigned int fr_cts;
+ unsigned int fr_ri;
+ unsigned int inv_fr;
+ bool access_32b;
+ bool oversampling;
+ bool dma_threshold;
+ bool cts_event_workaround;
+ bool always_enabled;
+ bool fixed_options;
+
+ unsigned int (*get_fifosize)(struct amba_device *dev);
+};
+
+static unsigned int get_fifosize_arm(struct amba_device *dev)
+{
+ return amba_rev(dev) < 3 ? 16 : 32;
+}
+
+static struct vendor_data vendor_arm = {
+ .reg_offset = pl011_std_offsets,
+ .ifls = UART011_IFLS_RX4_8|UART011_IFLS_TX4_8,
+ .fr_busy = UART01x_FR_BUSY,
+ .fr_dsr = UART01x_FR_DSR,
+ .fr_cts = UART01x_FR_CTS,
+ .fr_ri = UART011_FR_RI,
+ .oversampling = false,
+ .dma_threshold = false,
+ .cts_event_workaround = false,
+ .always_enabled = false,
+ .fixed_options = false,
+ .get_fifosize = get_fifosize_arm,
+};
+
+static const struct vendor_data vendor_sbsa = {
+ .reg_offset = pl011_std_offsets,
+ .fr_busy = UART01x_FR_BUSY,
+ .fr_dsr = UART01x_FR_DSR,
+ .fr_cts = UART01x_FR_CTS,
+ .fr_ri = UART011_FR_RI,
+ .access_32b = true,
+ .oversampling = false,
+ .dma_threshold = false,
+ .cts_event_workaround = false,
+ .always_enabled = true,
+ .fixed_options = true,
+};
+
+#ifdef CONFIG_ACPI_SPCR_TABLE
+static const struct vendor_data vendor_qdt_qdf2400_e44 = {
+ .reg_offset = pl011_std_offsets,
+ .fr_busy = UART011_FR_TXFE,
+ .fr_dsr = UART01x_FR_DSR,
+ .fr_cts = UART01x_FR_CTS,
+ .fr_ri = UART011_FR_RI,
+ .inv_fr = UART011_FR_TXFE,
+ .access_32b = true,
+ .oversampling = false,
+ .dma_threshold = false,
+ .cts_event_workaround = false,
+ .always_enabled = true,
+ .fixed_options = true,
+};
+#endif
+
+static u16 pl011_st_offsets[REG_ARRAY_SIZE] = {
+ [REG_DR] = UART01x_DR,
+ [REG_ST_DMAWM] = ST_UART011_DMAWM,
+ [REG_ST_TIMEOUT] = ST_UART011_TIMEOUT,
+ [REG_FR] = UART01x_FR,
+ [REG_LCRH_RX] = ST_UART011_LCRH_RX,
+ [REG_LCRH_TX] = ST_UART011_LCRH_TX,
+ [REG_IBRD] = UART011_IBRD,
+ [REG_FBRD] = UART011_FBRD,
+ [REG_CR] = UART011_CR,
+ [REG_IFLS] = UART011_IFLS,
+ [REG_IMSC] = UART011_IMSC,
+ [REG_RIS] = UART011_RIS,
+ [REG_MIS] = UART011_MIS,
+ [REG_ICR] = UART011_ICR,
+ [REG_DMACR] = UART011_DMACR,
+ [REG_ST_XFCR] = ST_UART011_XFCR,
+ [REG_ST_XON1] = ST_UART011_XON1,
+ [REG_ST_XON2] = ST_UART011_XON2,
+ [REG_ST_XOFF1] = ST_UART011_XOFF1,
+ [REG_ST_XOFF2] = ST_UART011_XOFF2,
+ [REG_ST_ITCR] = ST_UART011_ITCR,
+ [REG_ST_ITIP] = ST_UART011_ITIP,
+ [REG_ST_ABCR] = ST_UART011_ABCR,
+ [REG_ST_ABIMSC] = ST_UART011_ABIMSC,
+};
+
+static unsigned int get_fifosize_st(struct amba_device *dev)
+{
+ return 64;
+}
+
+static struct vendor_data vendor_st = {
+ .reg_offset = pl011_st_offsets,
+ .ifls = UART011_IFLS_RX_HALF|UART011_IFLS_TX_HALF,
+ .fr_busy = UART01x_FR_BUSY,
+ .fr_dsr = UART01x_FR_DSR,
+ .fr_cts = UART01x_FR_CTS,
+ .fr_ri = UART011_FR_RI,
+ .oversampling = true,
+ .dma_threshold = true,
+ .cts_event_workaround = true,
+ .always_enabled = false,
+ .fixed_options = false,
+ .get_fifosize = get_fifosize_st,
+};
+
+/* Deals with DMA transactions */
+
+struct pl011_dmabuf {
+ dma_addr_t dma;
+ size_t len;
+ char *buf;
+};
+
+struct pl011_dmarx_data {
+ struct dma_chan *chan;
+ struct completion complete;
+ bool use_buf_b;
+ struct pl011_dmabuf dbuf_a;
+ struct pl011_dmabuf dbuf_b;
+ dma_cookie_t cookie;
+ bool running;
+ struct timer_list timer;
+ unsigned int last_residue;
+ unsigned long last_jiffies;
+ bool auto_poll_rate;
+ unsigned int poll_rate;
+ unsigned int poll_timeout;
+};
+
+struct pl011_dmatx_data {
+ struct dma_chan *chan;
+ dma_addr_t dma;
+ size_t len;
+ char *buf;
+ bool queued;
+};
+
+/*
+ * We wrap our port structure around the generic uart_port.
+ */
+struct uart_amba_port {
+ struct uart_port port;
+ const u16 *reg_offset;
+ struct clk *clk;
+ const struct vendor_data *vendor;
+ unsigned int dmacr; /* dma control reg */
+ unsigned int im; /* interrupt mask */
+ unsigned int old_status;
+ unsigned int fifosize; /* vendor-specific */
+ unsigned int fixed_baud; /* vendor-set fixed baud rate */
+ char type[12];
+ bool rs485_tx_started;
+ unsigned int rs485_tx_drain_interval; /* usecs */
+#ifdef CONFIG_DMA_ENGINE
+ /* DMA stuff */
+ bool using_tx_dma;
+ bool using_rx_dma;
+ struct pl011_dmarx_data dmarx;
+ struct pl011_dmatx_data dmatx;
+ bool dma_probed;
+#endif
+};
+
+static unsigned int pl011_tx_empty(struct uart_port *port);
+
+static unsigned int pl011_reg_to_offset(const struct uart_amba_port *uap,
+ unsigned int reg)
+{
+ return uap->reg_offset[reg];
+}
+
+static unsigned int pl011_read(const struct uart_amba_port *uap,
+ unsigned int reg)
+{
+ void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg);
+
+ return (uap->port.iotype == UPIO_MEM32) ?
+ readl_relaxed(addr) : readw_relaxed(addr);
+}
+
+static void pl011_write(unsigned int val, const struct uart_amba_port *uap,
+ unsigned int reg)
+{
+ void __iomem *addr = uap->port.membase + pl011_reg_to_offset(uap, reg);
+
+ if (uap->port.iotype == UPIO_MEM32)
+ writel_relaxed(val, addr);
+ else
+ writew_relaxed(val, addr);
+}
+
+/*
+ * Reads up to 256 characters from the FIFO or until it's empty and
+ * inserts them into the TTY layer. Returns the number of characters
+ * read from the FIFO.
+ */
+static int pl011_fifo_to_tty(struct uart_amba_port *uap)
+{
+ unsigned int ch, flag, fifotaken;
+ int sysrq;
+ u16 status;
+
+ for (fifotaken = 0; fifotaken != 256; fifotaken++) {
+ status = pl011_read(uap, REG_FR);
+ if (status & UART01x_FR_RXFE)
+ break;
+
+ /* Take chars from the FIFO and update status */
+ ch = pl011_read(uap, REG_DR) | UART_DUMMY_DR_RX;
+ flag = TTY_NORMAL;
+ uap->port.icount.rx++;
+
+ if (unlikely(ch & UART_DR_ERROR)) {
+ if (ch & UART011_DR_BE) {
+ ch &= ~(UART011_DR_FE | UART011_DR_PE);
+ uap->port.icount.brk++;
+ if (uart_handle_break(&uap->port))
+ continue;
+ } else if (ch & UART011_DR_PE)
+ uap->port.icount.parity++;
+ else if (ch & UART011_DR_FE)
+ uap->port.icount.frame++;
+ if (ch & UART011_DR_OE)
+ uap->port.icount.overrun++;
+
+ ch &= uap->port.read_status_mask;
+
+ if (ch & UART011_DR_BE)
+ flag = TTY_BREAK;
+ else if (ch & UART011_DR_PE)
+ flag = TTY_PARITY;
+ else if (ch & UART011_DR_FE)
+ flag = TTY_FRAME;
+ }
+
+ spin_unlock(&uap->port.lock);
+ sysrq = uart_handle_sysrq_char(&uap->port, ch & 255);
+ spin_lock(&uap->port.lock);
+
+ if (!sysrq)
+ uart_insert_char(&uap->port, ch, UART011_DR_OE, ch, flag);
+ }
+
+ return fifotaken;
+}
+
+
+/*
+ * All the DMA operation mode stuff goes inside this ifdef.
+ * This assumes that you have a generic DMA device interface,
+ * no custom DMA interfaces are supported.
+ */
+#ifdef CONFIG_DMA_ENGINE
+
+#define PL011_DMA_BUFFER_SIZE PAGE_SIZE
+
+static int pl011_dmabuf_init(struct dma_chan *chan, struct pl011_dmabuf *db,
+ enum dma_data_direction dir)
+{
+ db->buf = dma_alloc_coherent(chan->device->dev, PL011_DMA_BUFFER_SIZE,
+ &db->dma, GFP_KERNEL);
+ if (!db->buf)
+ return -ENOMEM;
+ db->len = PL011_DMA_BUFFER_SIZE;
+
+ return 0;
+}
+
+static void pl011_dmabuf_free(struct dma_chan *chan, struct pl011_dmabuf *db,
+ enum dma_data_direction dir)
+{
+ if (db->buf) {
+ dma_free_coherent(chan->device->dev,
+ PL011_DMA_BUFFER_SIZE, db->buf, db->dma);
+ }
+}
+
+static void pl011_dma_probe(struct uart_amba_port *uap)
+{
+ /* DMA is the sole user of the platform data right now */
+ struct amba_pl011_data *plat = dev_get_platdata(uap->port.dev);
+ struct device *dev = uap->port.dev;
+ struct dma_slave_config tx_conf = {
+ .dst_addr = uap->port.mapbase +
+ pl011_reg_to_offset(uap, REG_DR),
+ .dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
+ .direction = DMA_MEM_TO_DEV,
+ .dst_maxburst = uap->fifosize >> 1,
+ .device_fc = false,
+ };
+ struct dma_chan *chan;
+ dma_cap_mask_t mask;
+
+ uap->dma_probed = true;
+ chan = dma_request_chan(dev, "tx");
+ if (IS_ERR(chan)) {
+ if (PTR_ERR(chan) == -EPROBE_DEFER) {
+ uap->dma_probed = false;
+ return;
+ }
+
+ /* We need platform data */
+ if (!plat || !plat->dma_filter) {
+ dev_info(uap->port.dev, "no DMA platform data\n");
+ return;
+ }
+
+ /* Try to acquire a generic DMA engine slave TX channel */
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+
+ chan = dma_request_channel(mask, plat->dma_filter,
+ plat->dma_tx_param);
+ if (!chan) {
+ dev_err(uap->port.dev, "no TX DMA channel!\n");
+ return;
+ }
+ }
+
+ dmaengine_slave_config(chan, &tx_conf);
+ uap->dmatx.chan = chan;
+
+ dev_info(uap->port.dev, "DMA channel TX %s\n",
+ dma_chan_name(uap->dmatx.chan));
+
+ /* Optionally make use of an RX channel as well */
+ chan = dma_request_slave_channel(dev, "rx");
+
+ if (!chan && plat && plat->dma_rx_param) {
+ chan = dma_request_channel(mask, plat->dma_filter, plat->dma_rx_param);
+
+ if (!chan) {
+ dev_err(uap->port.dev, "no RX DMA channel!\n");
+ return;
+ }
+ }
+
+ if (chan) {
+ struct dma_slave_config rx_conf = {
+ .src_addr = uap->port.mapbase +
+ pl011_reg_to_offset(uap, REG_DR),
+ .src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE,
+ .direction = DMA_DEV_TO_MEM,
+ .src_maxburst = uap->fifosize >> 2,
+ .device_fc = false,
+ };
+ struct dma_slave_caps caps;
+
+ /*
+ * Some DMA controllers provide information on their capabilities.
+ * If the controller does, check for suitable residue processing
+ * otherwise assime all is well.
+ */
+ if (0 == dma_get_slave_caps(chan, &caps)) {
+ if (caps.residue_granularity ==
+ DMA_RESIDUE_GRANULARITY_DESCRIPTOR) {
+ dma_release_channel(chan);
+ dev_info(uap->port.dev,
+ "RX DMA disabled - no residue processing\n");
+ return;
+ }
+ }
+ dmaengine_slave_config(chan, &rx_conf);
+ uap->dmarx.chan = chan;
+
+ uap->dmarx.auto_poll_rate = false;
+ if (plat && plat->dma_rx_poll_enable) {
+ /* Set poll rate if specified. */
+ if (plat->dma_rx_poll_rate) {
+ uap->dmarx.auto_poll_rate = false;
+ uap->dmarx.poll_rate = plat->dma_rx_poll_rate;
+ } else {
+ /*
+ * 100 ms defaults to poll rate if not
+ * specified. This will be adjusted with
+ * the baud rate at set_termios.
+ */
+ uap->dmarx.auto_poll_rate = true;
+ uap->dmarx.poll_rate = 100;
+ }
+ /* 3 secs defaults poll_timeout if not specified. */
+ if (plat->dma_rx_poll_timeout)
+ uap->dmarx.poll_timeout =
+ plat->dma_rx_poll_timeout;
+ else
+ uap->dmarx.poll_timeout = 3000;
+ } else if (!plat && dev->of_node) {
+ uap->dmarx.auto_poll_rate = of_property_read_bool(
+ dev->of_node, "auto-poll");
+ if (uap->dmarx.auto_poll_rate) {
+ u32 x;
+
+ if (0 == of_property_read_u32(dev->of_node,
+ "poll-rate-ms", &x))
+ uap->dmarx.poll_rate = x;
+ else
+ uap->dmarx.poll_rate = 100;
+ if (0 == of_property_read_u32(dev->of_node,
+ "poll-timeout-ms", &x))
+ uap->dmarx.poll_timeout = x;
+ else
+ uap->dmarx.poll_timeout = 3000;
+ }
+ }
+ dev_info(uap->port.dev, "DMA channel RX %s\n",
+ dma_chan_name(uap->dmarx.chan));
+ }
+}
+
+static void pl011_dma_remove(struct uart_amba_port *uap)
+{
+ if (uap->dmatx.chan)
+ dma_release_channel(uap->dmatx.chan);
+ if (uap->dmarx.chan)
+ dma_release_channel(uap->dmarx.chan);
+}
+
+/* Forward declare these for the refill routine */
+static int pl011_dma_tx_refill(struct uart_amba_port *uap);
+static void pl011_start_tx_pio(struct uart_amba_port *uap);
+
+/*
+ * The current DMA TX buffer has been sent.
+ * Try to queue up another DMA buffer.
+ */
+static void pl011_dma_tx_callback(void *data)
+{
+ struct uart_amba_port *uap = data;
+ struct pl011_dmatx_data *dmatx = &uap->dmatx;
+ unsigned long flags;
+ u16 dmacr;
+
+ spin_lock_irqsave(&uap->port.lock, flags);
+ if (uap->dmatx.queued)
+ dma_unmap_single(dmatx->chan->device->dev, dmatx->dma,
+ dmatx->len, DMA_TO_DEVICE);
+
+ dmacr = uap->dmacr;
+ uap->dmacr = dmacr & ~UART011_TXDMAE;
+ pl011_write(uap->dmacr, uap, REG_DMACR);
+
+ /*
+ * If TX DMA was disabled, it means that we've stopped the DMA for
+ * some reason (eg, XOFF received, or we want to send an X-char.)
+ *
+ * Note: we need to be careful here of a potential race between DMA
+ * and the rest of the driver - if the driver disables TX DMA while
+ * a TX buffer completing, we must update the tx queued status to
+ * get further refills (hence we check dmacr).
+ */
+ if (!(dmacr & UART011_TXDMAE) || uart_tx_stopped(&uap->port) ||
+ uart_circ_empty(&uap->port.state->xmit)) {
+ uap->dmatx.queued = false;
+ spin_unlock_irqrestore(&uap->port.lock, flags);
+ return;
+ }
+
+ if (pl011_dma_tx_refill(uap) <= 0)
+ /*
+ * We didn't queue a DMA buffer for some reason, but we
+ * have data pending to be sent. Re-enable the TX IRQ.
+ */
+ pl011_start_tx_pio(uap);
+
+ spin_unlock_irqrestore(&uap->port.lock, flags);
+}
+
+/*
+ * Try to refill the TX DMA buffer.
+ * Locking: called with port lock held and IRQs disabled.
+ * Returns:
+ * 1 if we queued up a TX DMA buffer.
+ * 0 if we didn't want to handle this by DMA
+ * <0 on error
+ */
+static int pl011_dma_tx_refill(struct uart_amba_port *uap)
+{
+ struct pl011_dmatx_data *dmatx = &uap->dmatx;
+ struct dma_chan *chan = dmatx->chan;
+ struct dma_device *dma_dev = chan->device;
+ struct dma_async_tx_descriptor *desc;
+ struct circ_buf *xmit = &uap->port.state->xmit;
+ unsigned int count;
+
+ /*
+ * Try to avoid the overhead involved in using DMA if the
+ * transaction fits in the first half of the FIFO, by using
+ * the standard interrupt handling. This ensures that we
+ * issue a uart_write_wakeup() at the appropriate time.
+ */
+ count = uart_circ_chars_pending(xmit);
+ if (count < (uap->fifosize >> 1)) {
+ uap->dmatx.queued = false;
+ return 0;
+ }
+
+ /*
+ * Bodge: don't send the last character by DMA, as this
+ * will prevent XON from notifying us to restart DMA.
+ */
+ count -= 1;
+
+ /* Else proceed to copy the TX chars to the DMA buffer and fire DMA */
+ if (count > PL011_DMA_BUFFER_SIZE)
+ count = PL011_DMA_BUFFER_SIZE;
+
+ if (xmit->tail < xmit->head)
+ memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], count);
+ else {
+ size_t first = UART_XMIT_SIZE - xmit->tail;
+ size_t second;
+
+ if (first > count)
+ first = count;
+ second = count - first;
+
+ memcpy(&dmatx->buf[0], &xmit->buf[xmit->tail], first);
+ if (second)
+ memcpy(&dmatx->buf[first], &xmit->buf[0], second);
+ }
+
+ dmatx->len = count;
+ dmatx->dma = dma_map_single(dma_dev->dev, dmatx->buf, count,
+ DMA_TO_DEVICE);
+ if (dmatx->dma == DMA_MAPPING_ERROR) {
+ uap->dmatx.queued = false;
+ dev_dbg(uap->port.dev, "unable to map TX DMA\n");
+ return -EBUSY;
+ }
+
+ desc = dmaengine_prep_slave_single(chan, dmatx->dma, dmatx->len, DMA_MEM_TO_DEV,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!desc) {
+ dma_unmap_single(dma_dev->dev, dmatx->dma, dmatx->len, DMA_TO_DEVICE);
+ uap->dmatx.queued = false;
+ /*
+ * If DMA cannot be used right now, we complete this
+ * transaction via IRQ and let the TTY layer retry.
+ */
+ dev_dbg(uap->port.dev, "TX DMA busy\n");
+ return -EBUSY;
+ }
+
+ /* Some data to go along to the callback */
+ desc->callback = pl011_dma_tx_callback;
+ desc->callback_param = uap;
+
+ /* All errors should happen at prepare time */
+ dmaengine_submit(desc);
+
+ /* Fire the DMA transaction */
+ dma_dev->device_issue_pending(chan);
+
+ uap->dmacr |= UART011_TXDMAE;
+ pl011_write(uap->dmacr, uap, REG_DMACR);
+ uap->dmatx.queued = true;
+
+ /*
+ * Now we know that DMA will fire, so advance the ring buffer
+ * with the stuff we just dispatched.
+ */
+ xmit->tail = (xmit->tail + count) & (UART_XMIT_SIZE - 1);
+ uap->port.icount.tx += count;
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(&uap->port);
+
+ return 1;
+}
+
+/*
+ * We received a transmit interrupt without a pending X-char but with
+ * pending characters.
+ * Locking: called with port lock held and IRQs disabled.
+ * Returns:
+ * false if we want to use PIO to transmit
+ * true if we queued a DMA buffer
+ */
+static bool pl011_dma_tx_irq(struct uart_amba_port *uap)
+{
+ if (!uap->using_tx_dma)
+ return false;
+
+ /*
+ * If we already have a TX buffer queued, but received a
+ * TX interrupt, it will be because we've just sent an X-char.
+ * Ensure the TX DMA is enabled and the TX IRQ is disabled.
+ */
+ if (uap->dmatx.queued) {
+ uap->dmacr |= UART011_TXDMAE;
+ pl011_write(uap->dmacr, uap, REG_DMACR);
+ uap->im &= ~UART011_TXIM;
+ pl011_write(uap->im, uap, REG_IMSC);
+ return true;
+ }
+
+ /*
+ * We don't have a TX buffer queued, so try to queue one.
+ * If we successfully queued a buffer, mask the TX IRQ.
+ */
+ if (pl011_dma_tx_refill(uap) > 0) {
+ uap->im &= ~UART011_TXIM;
+ pl011_write(uap->im, uap, REG_IMSC);
+ return true;
+ }
+ return false;
+}
+
+/*
+ * Stop the DMA transmit (eg, due to received XOFF).
+ * Locking: called with port lock held and IRQs disabled.
+ */
+static inline void pl011_dma_tx_stop(struct uart_amba_port *uap)
+{
+ if (uap->dmatx.queued) {
+ uap->dmacr &= ~UART011_TXDMAE;
+ pl011_write(uap->dmacr, uap, REG_DMACR);
+ }
+}
+
+/*
+ * Try to start a DMA transmit, or in the case of an XON/OFF
+ * character queued for send, try to get that character out ASAP.
+ * Locking: called with port lock held and IRQs disabled.
+ * Returns:
+ * false if we want the TX IRQ to be enabled
+ * true if we have a buffer queued
+ */
+static inline bool pl011_dma_tx_start(struct uart_amba_port *uap)
+{
+ u16 dmacr;
+
+ if (!uap->using_tx_dma)
+ return false;
+
+ if (!uap->port.x_char) {
+ /* no X-char, try to push chars out in DMA mode */
+ bool ret = true;
+
+ if (!uap->dmatx.queued) {
+ if (pl011_dma_tx_refill(uap) > 0) {
+ uap->im &= ~UART011_TXIM;
+ pl011_write(uap->im, uap, REG_IMSC);
+ } else
+ ret = false;
+ } else if (!(uap->dmacr & UART011_TXDMAE)) {
+ uap->dmacr |= UART011_TXDMAE;
+ pl011_write(uap->dmacr, uap, REG_DMACR);
+ }
+ return ret;
+ }
+
+ /*
+ * We have an X-char to send. Disable DMA to prevent it loading
+ * the TX fifo, and then see if we can stuff it into the FIFO.
+ */
+ dmacr = uap->dmacr;
+ uap->dmacr &= ~UART011_TXDMAE;
+ pl011_write(uap->dmacr, uap, REG_DMACR);
+
+ if (pl011_read(uap, REG_FR) & UART01x_FR_TXFF) {
+ /*
+ * No space in the FIFO, so enable the transmit interrupt
+ * so we know when there is space. Note that once we've
+ * loaded the character, we should just re-enable DMA.
+ */
+ return false;
+ }
+
+ pl011_write(uap->port.x_char, uap, REG_DR);
+ uap->port.icount.tx++;
+ uap->port.x_char = 0;
+
+ /* Success - restore the DMA state */
+ uap->dmacr = dmacr;
+ pl011_write(dmacr, uap, REG_DMACR);
+
+ return true;
+}
+
+/*
+ * Flush the transmit buffer.
+ * Locking: called with port lock held and IRQs disabled.
+ */
+static void pl011_dma_flush_buffer(struct uart_port *port)
+__releases(&uap->port.lock)
+__acquires(&uap->port.lock)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+
+ if (!uap->using_tx_dma)
+ return;
+
+ dmaengine_terminate_async(uap->dmatx.chan);
+
+ if (uap->dmatx.queued) {
+ dma_unmap_single(uap->dmatx.chan->device->dev, uap->dmatx.dma,
+ uap->dmatx.len, DMA_TO_DEVICE);
+ uap->dmatx.queued = false;
+ uap->dmacr &= ~UART011_TXDMAE;
+ pl011_write(uap->dmacr, uap, REG_DMACR);
+ }
+}
+
+static void pl011_dma_rx_callback(void *data);
+
+static int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap)
+{
+ struct dma_chan *rxchan = uap->dmarx.chan;
+ struct pl011_dmarx_data *dmarx = &uap->dmarx;
+ struct dma_async_tx_descriptor *desc;
+ struct pl011_dmabuf *dbuf;
+
+ if (!rxchan)
+ return -EIO;
+
+ /* Start the RX DMA job */
+ dbuf = uap->dmarx.use_buf_b ?
+ &uap->dmarx.dbuf_b : &uap->dmarx.dbuf_a;
+ desc = dmaengine_prep_slave_single(rxchan, dbuf->dma, dbuf->len,
+ DMA_DEV_TO_MEM,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ /*
+ * If the DMA engine is busy and cannot prepare a
+ * channel, no big deal, the driver will fall back
+ * to interrupt mode as a result of this error code.
+ */
+ if (!desc) {
+ uap->dmarx.running = false;
+ dmaengine_terminate_all(rxchan);
+ return -EBUSY;
+ }
+
+ /* Some data to go along to the callback */
+ desc->callback = pl011_dma_rx_callback;
+ desc->callback_param = uap;
+ dmarx->cookie = dmaengine_submit(desc);
+ dma_async_issue_pending(rxchan);
+
+ uap->dmacr |= UART011_RXDMAE;
+ pl011_write(uap->dmacr, uap, REG_DMACR);
+ uap->dmarx.running = true;
+
+ uap->im &= ~UART011_RXIM;
+ pl011_write(uap->im, uap, REG_IMSC);
+
+ return 0;
+}
+
+/*
+ * This is called when either the DMA job is complete, or
+ * the FIFO timeout interrupt occurred. This must be called
+ * with the port spinlock uap->port.lock held.
+ */
+static void pl011_dma_rx_chars(struct uart_amba_port *uap,
+ u32 pending, bool use_buf_b,
+ bool readfifo)
+{
+ struct tty_port *port = &uap->port.state->port;
+ struct pl011_dmabuf *dbuf = use_buf_b ?
+ &uap->dmarx.dbuf_b : &uap->dmarx.dbuf_a;
+ int dma_count = 0;
+ u32 fifotaken = 0; /* only used for vdbg() */
+
+ struct pl011_dmarx_data *dmarx = &uap->dmarx;
+ int dmataken = 0;
+
+ if (uap->dmarx.poll_rate) {
+ /* The data can be taken by polling */
+ dmataken = dbuf->len - dmarx->last_residue;
+ /* Recalculate the pending size */
+ if (pending >= dmataken)
+ pending -= dmataken;
+ }
+
+ /* Pick the remain data from the DMA */
+ if (pending) {
+
+ /*
+ * First take all chars in the DMA pipe, then look in the FIFO.
+ * Note that tty_insert_flip_buf() tries to take as many chars
+ * as it can.
+ */
+ dma_count = tty_insert_flip_string(port, dbuf->buf + dmataken,
+ pending);
+
+ uap->port.icount.rx += dma_count;
+ if (dma_count < pending)
+ dev_warn(uap->port.dev,
+ "couldn't insert all characters (TTY is full?)\n");
+ }
+
+ /* Reset the last_residue for Rx DMA poll */
+ if (uap->dmarx.poll_rate)
+ dmarx->last_residue = dbuf->len;
+
+ /*
+ * Only continue with trying to read the FIFO if all DMA chars have
+ * been taken first.
+ */
+ if (dma_count == pending && readfifo) {
+ /* Clear any error flags */
+ pl011_write(UART011_OEIS | UART011_BEIS | UART011_PEIS |
+ UART011_FEIS, uap, REG_ICR);
+
+ /*
+ * If we read all the DMA'd characters, and we had an
+ * incomplete buffer, that could be due to an rx error, or
+ * maybe we just timed out. Read any pending chars and check
+ * the error status.
+ *
+ * Error conditions will only occur in the FIFO, these will
+ * trigger an immediate interrupt and stop the DMA job, so we
+ * will always find the error in the FIFO, never in the DMA
+ * buffer.
+ */
+ fifotaken = pl011_fifo_to_tty(uap);
+ }
+
+ dev_vdbg(uap->port.dev,
+ "Took %d chars from DMA buffer and %d chars from the FIFO\n",
+ dma_count, fifotaken);
+ tty_flip_buffer_push(port);
+}
+
+static void pl011_dma_rx_irq(struct uart_amba_port *uap)
+{
+ struct pl011_dmarx_data *dmarx = &uap->dmarx;
+ struct dma_chan *rxchan = dmarx->chan;
+ struct pl011_dmabuf *dbuf = dmarx->use_buf_b ?
+ &dmarx->dbuf_b : &dmarx->dbuf_a;
+ size_t pending;
+ struct dma_tx_state state;
+ enum dma_status dmastat;
+
+ /*
+ * Pause the transfer so we can trust the current counter,
+ * do this before we pause the PL011 block, else we may
+ * overflow the FIFO.
+ */
+ if (dmaengine_pause(rxchan))
+ dev_err(uap->port.dev, "unable to pause DMA transfer\n");
+ dmastat = rxchan->device->device_tx_status(rxchan,
+ dmarx->cookie, &state);
+ if (dmastat != DMA_PAUSED)
+ dev_err(uap->port.dev, "unable to pause DMA transfer\n");
+
+ /* Disable RX DMA - incoming data will wait in the FIFO */
+ uap->dmacr &= ~UART011_RXDMAE;
+ pl011_write(uap->dmacr, uap, REG_DMACR);
+ uap->dmarx.running = false;
+
+ pending = dbuf->len - state.residue;
+ BUG_ON(pending > PL011_DMA_BUFFER_SIZE);
+ /* Then we terminate the transfer - we now know our residue */
+ dmaengine_terminate_all(rxchan);
+
+ /*
+ * This will take the chars we have so far and insert
+ * into the framework.
+ */
+ pl011_dma_rx_chars(uap, pending, dmarx->use_buf_b, true);
+
+ /* Switch buffer & re-trigger DMA job */
+ dmarx->use_buf_b = !dmarx->use_buf_b;
+ if (pl011_dma_rx_trigger_dma(uap)) {
+ dev_dbg(uap->port.dev, "could not retrigger RX DMA job "
+ "fall back to interrupt mode\n");
+ uap->im |= UART011_RXIM;
+ pl011_write(uap->im, uap, REG_IMSC);
+ }
+}
+
+static void pl011_dma_rx_callback(void *data)
+{
+ struct uart_amba_port *uap = data;
+ struct pl011_dmarx_data *dmarx = &uap->dmarx;
+ struct dma_chan *rxchan = dmarx->chan;
+ bool lastbuf = dmarx->use_buf_b;
+ struct pl011_dmabuf *dbuf = dmarx->use_buf_b ?
+ &dmarx->dbuf_b : &dmarx->dbuf_a;
+ size_t pending;
+ struct dma_tx_state state;
+ int ret;
+
+ /*
+ * This completion interrupt occurs typically when the
+ * RX buffer is totally stuffed but no timeout has yet
+ * occurred. When that happens, we just want the RX
+ * routine to flush out the secondary DMA buffer while
+ * we immediately trigger the next DMA job.
+ */
+ spin_lock_irq(&uap->port.lock);
+ /*
+ * Rx data can be taken by the UART interrupts during
+ * the DMA irq handler. So we check the residue here.
+ */
+ rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state);
+ pending = dbuf->len - state.residue;
+ BUG_ON(pending > PL011_DMA_BUFFER_SIZE);
+ /* Then we terminate the transfer - we now know our residue */
+ dmaengine_terminate_all(rxchan);
+
+ uap->dmarx.running = false;
+ dmarx->use_buf_b = !lastbuf;
+ ret = pl011_dma_rx_trigger_dma(uap);
+
+ pl011_dma_rx_chars(uap, pending, lastbuf, false);
+ spin_unlock_irq(&uap->port.lock);
+ /*
+ * Do this check after we picked the DMA chars so we don't
+ * get some IRQ immediately from RX.
+ */
+ if (ret) {
+ dev_dbg(uap->port.dev, "could not retrigger RX DMA job "
+ "fall back to interrupt mode\n");
+ uap->im |= UART011_RXIM;
+ pl011_write(uap->im, uap, REG_IMSC);
+ }
+}
+
+/*
+ * Stop accepting received characters, when we're shutting down or
+ * suspending this port.
+ * Locking: called with port lock held and IRQs disabled.
+ */
+static inline void pl011_dma_rx_stop(struct uart_amba_port *uap)
+{
+ if (!uap->using_rx_dma)
+ return;
+
+ /* FIXME. Just disable the DMA enable */
+ uap->dmacr &= ~UART011_RXDMAE;
+ pl011_write(uap->dmacr, uap, REG_DMACR);
+}
+
+/*
+ * Timer handler for Rx DMA polling.
+ * Every polling, It checks the residue in the dma buffer and transfer
+ * data to the tty. Also, last_residue is updated for the next polling.
+ */
+static void pl011_dma_rx_poll(struct timer_list *t)
+{
+ struct uart_amba_port *uap = from_timer(uap, t, dmarx.timer);
+ struct tty_port *port = &uap->port.state->port;
+ struct pl011_dmarx_data *dmarx = &uap->dmarx;
+ struct dma_chan *rxchan = uap->dmarx.chan;
+ unsigned long flags;
+ unsigned int dmataken = 0;
+ unsigned int size = 0;
+ struct pl011_dmabuf *dbuf;
+ int dma_count;
+ struct dma_tx_state state;
+
+ dbuf = dmarx->use_buf_b ? &uap->dmarx.dbuf_b : &uap->dmarx.dbuf_a;
+ rxchan->device->device_tx_status(rxchan, dmarx->cookie, &state);
+ if (likely(state.residue < dmarx->last_residue)) {
+ dmataken = dbuf->len - dmarx->last_residue;
+ size = dmarx->last_residue - state.residue;
+ dma_count = tty_insert_flip_string(port, dbuf->buf + dmataken,
+ size);
+ if (dma_count == size)
+ dmarx->last_residue = state.residue;
+ dmarx->last_jiffies = jiffies;
+ }
+ tty_flip_buffer_push(port);
+
+ /*
+ * If no data is received in poll_timeout, the driver will fall back
+ * to interrupt mode. We will retrigger DMA at the first interrupt.
+ */
+ if (jiffies_to_msecs(jiffies - dmarx->last_jiffies)
+ > uap->dmarx.poll_timeout) {
+
+ spin_lock_irqsave(&uap->port.lock, flags);
+ pl011_dma_rx_stop(uap);
+ uap->im |= UART011_RXIM;
+ pl011_write(uap->im, uap, REG_IMSC);
+ spin_unlock_irqrestore(&uap->port.lock, flags);
+
+ uap->dmarx.running = false;
+ dmaengine_terminate_all(rxchan);
+ del_timer(&uap->dmarx.timer);
+ } else {
+ mod_timer(&uap->dmarx.timer,
+ jiffies + msecs_to_jiffies(uap->dmarx.poll_rate));
+ }
+}
+
+static void pl011_dma_startup(struct uart_amba_port *uap)
+{
+ int ret;
+
+ if (!uap->dma_probed)
+ pl011_dma_probe(uap);
+
+ if (!uap->dmatx.chan)
+ return;
+
+ uap->dmatx.buf = kmalloc(PL011_DMA_BUFFER_SIZE, GFP_KERNEL | __GFP_DMA);
+ if (!uap->dmatx.buf) {
+ dev_err(uap->port.dev, "no memory for DMA TX buffer\n");
+ uap->port.fifosize = uap->fifosize;
+ return;
+ }
+
+ uap->dmatx.len = PL011_DMA_BUFFER_SIZE;
+
+ /* The DMA buffer is now the FIFO the TTY subsystem can use */
+ uap->port.fifosize = PL011_DMA_BUFFER_SIZE;
+ uap->using_tx_dma = true;
+
+ if (!uap->dmarx.chan)
+ goto skip_rx;
+
+ /* Allocate and map DMA RX buffers */
+ ret = pl011_dmabuf_init(uap->dmarx.chan, &uap->dmarx.dbuf_a,
+ DMA_FROM_DEVICE);
+ if (ret) {
+ dev_err(uap->port.dev, "failed to init DMA %s: %d\n",
+ "RX buffer A", ret);
+ goto skip_rx;
+ }
+
+ ret = pl011_dmabuf_init(uap->dmarx.chan, &uap->dmarx.dbuf_b,
+ DMA_FROM_DEVICE);
+ if (ret) {
+ dev_err(uap->port.dev, "failed to init DMA %s: %d\n",
+ "RX buffer B", ret);
+ pl011_dmabuf_free(uap->dmarx.chan, &uap->dmarx.dbuf_a,
+ DMA_FROM_DEVICE);
+ goto skip_rx;
+ }
+
+ uap->using_rx_dma = true;
+
+skip_rx:
+ /* Turn on DMA error (RX/TX will be enabled on demand) */
+ uap->dmacr |= UART011_DMAONERR;
+ pl011_write(uap->dmacr, uap, REG_DMACR);
+
+ /*
+ * ST Micro variants has some specific dma burst threshold
+ * compensation. Set this to 16 bytes, so burst will only
+ * be issued above/below 16 bytes.
+ */
+ if (uap->vendor->dma_threshold)
+ pl011_write(ST_UART011_DMAWM_RX_16 | ST_UART011_DMAWM_TX_16,
+ uap, REG_ST_DMAWM);
+
+ if (uap->using_rx_dma) {
+ if (pl011_dma_rx_trigger_dma(uap))
+ dev_dbg(uap->port.dev, "could not trigger initial "
+ "RX DMA job, fall back to interrupt mode\n");
+ if (uap->dmarx.poll_rate) {
+ timer_setup(&uap->dmarx.timer, pl011_dma_rx_poll, 0);
+ mod_timer(&uap->dmarx.timer,
+ jiffies +
+ msecs_to_jiffies(uap->dmarx.poll_rate));
+ uap->dmarx.last_residue = PL011_DMA_BUFFER_SIZE;
+ uap->dmarx.last_jiffies = jiffies;
+ }
+ }
+}
+
+static void pl011_dma_shutdown(struct uart_amba_port *uap)
+{
+ if (!(uap->using_tx_dma || uap->using_rx_dma))
+ return;
+
+ /* Disable RX and TX DMA */
+ while (pl011_read(uap, REG_FR) & uap->vendor->fr_busy)
+ cpu_relax();
+
+ spin_lock_irq(&uap->port.lock);
+ uap->dmacr &= ~(UART011_DMAONERR | UART011_RXDMAE | UART011_TXDMAE);
+ pl011_write(uap->dmacr, uap, REG_DMACR);
+ spin_unlock_irq(&uap->port.lock);
+
+ if (uap->using_tx_dma) {
+ /* In theory, this should already be done by pl011_dma_flush_buffer */
+ dmaengine_terminate_all(uap->dmatx.chan);
+ if (uap->dmatx.queued) {
+ dma_unmap_single(uap->dmatx.chan->device->dev,
+ uap->dmatx.dma, uap->dmatx.len,
+ DMA_TO_DEVICE);
+ uap->dmatx.queued = false;
+ }
+
+ kfree(uap->dmatx.buf);
+ uap->using_tx_dma = false;
+ }
+
+ if (uap->using_rx_dma) {
+ dmaengine_terminate_all(uap->dmarx.chan);
+ /* Clean up the RX DMA */
+ pl011_dmabuf_free(uap->dmarx.chan, &uap->dmarx.dbuf_a, DMA_FROM_DEVICE);
+ pl011_dmabuf_free(uap->dmarx.chan, &uap->dmarx.dbuf_b, DMA_FROM_DEVICE);
+ if (uap->dmarx.poll_rate)
+ del_timer_sync(&uap->dmarx.timer);
+ uap->using_rx_dma = false;
+ }
+}
+
+static inline bool pl011_dma_rx_available(struct uart_amba_port *uap)
+{
+ return uap->using_rx_dma;
+}
+
+static inline bool pl011_dma_rx_running(struct uart_amba_port *uap)
+{
+ return uap->using_rx_dma && uap->dmarx.running;
+}
+
+#else
+/* Blank functions if the DMA engine is not available */
+static inline void pl011_dma_remove(struct uart_amba_port *uap)
+{
+}
+
+static inline void pl011_dma_startup(struct uart_amba_port *uap)
+{
+}
+
+static inline void pl011_dma_shutdown(struct uart_amba_port *uap)
+{
+}
+
+static inline bool pl011_dma_tx_irq(struct uart_amba_port *uap)
+{
+ return false;
+}
+
+static inline void pl011_dma_tx_stop(struct uart_amba_port *uap)
+{
+}
+
+static inline bool pl011_dma_tx_start(struct uart_amba_port *uap)
+{
+ return false;
+}
+
+static inline void pl011_dma_rx_irq(struct uart_amba_port *uap)
+{
+}
+
+static inline void pl011_dma_rx_stop(struct uart_amba_port *uap)
+{
+}
+
+static inline int pl011_dma_rx_trigger_dma(struct uart_amba_port *uap)
+{
+ return -EIO;
+}
+
+static inline bool pl011_dma_rx_available(struct uart_amba_port *uap)
+{
+ return false;
+}
+
+static inline bool pl011_dma_rx_running(struct uart_amba_port *uap)
+{
+ return false;
+}
+
+#define pl011_dma_flush_buffer NULL
+#endif
+
+static void pl011_rs485_tx_stop(struct uart_amba_port *uap)
+{
+ /*
+ * To be on the safe side only time out after twice as many iterations
+ * as fifo size.
+ */
+ const int MAX_TX_DRAIN_ITERS = uap->port.fifosize * 2;
+ struct uart_port *port = &uap->port;
+ int i = 0;
+ u32 cr;
+
+ /* Wait until hardware tx queue is empty */
+ while (!pl011_tx_empty(port)) {
+ if (i > MAX_TX_DRAIN_ITERS) {
+ dev_warn(port->dev,
+ "timeout while draining hardware tx queue\n");
+ break;
+ }
+
+ udelay(uap->rs485_tx_drain_interval);
+ i++;
+ }
+
+ if (port->rs485.delay_rts_after_send)
+ mdelay(port->rs485.delay_rts_after_send);
+
+ cr = pl011_read(uap, REG_CR);
+
+ if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
+ cr &= ~UART011_CR_RTS;
+ else
+ cr |= UART011_CR_RTS;
+
+ /* Disable the transmitter and reenable the transceiver */
+ cr &= ~UART011_CR_TXE;
+ cr |= UART011_CR_RXE;
+ pl011_write(cr, uap, REG_CR);
+
+ uap->rs485_tx_started = false;
+}
+
+static void pl011_stop_tx(struct uart_port *port)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+
+ uap->im &= ~UART011_TXIM;
+ pl011_write(uap->im, uap, REG_IMSC);
+ pl011_dma_tx_stop(uap);
+
+ if ((port->rs485.flags & SER_RS485_ENABLED) && uap->rs485_tx_started)
+ pl011_rs485_tx_stop(uap);
+}
+
+static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq);
+
+/* Start TX with programmed I/O only (no DMA) */
+static void pl011_start_tx_pio(struct uart_amba_port *uap)
+{
+ if (pl011_tx_chars(uap, false)) {
+ uap->im |= UART011_TXIM;
+ pl011_write(uap->im, uap, REG_IMSC);
+ }
+}
+
+static void pl011_start_tx(struct uart_port *port)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+
+ if (!pl011_dma_tx_start(uap))
+ pl011_start_tx_pio(uap);
+}
+
+static void pl011_stop_rx(struct uart_port *port)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+
+ uap->im &= ~(UART011_RXIM|UART011_RTIM|UART011_FEIM|
+ UART011_PEIM|UART011_BEIM|UART011_OEIM);
+ pl011_write(uap->im, uap, REG_IMSC);
+
+ pl011_dma_rx_stop(uap);
+}
+
+static void pl011_throttle_rx(struct uart_port *port)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ pl011_stop_rx(port);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void pl011_enable_ms(struct uart_port *port)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+
+ uap->im |= UART011_RIMIM|UART011_CTSMIM|UART011_DCDMIM|UART011_DSRMIM;
+ pl011_write(uap->im, uap, REG_IMSC);
+}
+
+static void pl011_rx_chars(struct uart_amba_port *uap)
+__releases(&uap->port.lock)
+__acquires(&uap->port.lock)
+{
+ pl011_fifo_to_tty(uap);
+
+ spin_unlock(&uap->port.lock);
+ tty_flip_buffer_push(&uap->port.state->port);
+ /*
+ * If we were temporarily out of DMA mode for a while,
+ * attempt to switch back to DMA mode again.
+ */
+ if (pl011_dma_rx_available(uap)) {
+ if (pl011_dma_rx_trigger_dma(uap)) {
+ dev_dbg(uap->port.dev, "could not trigger RX DMA job "
+ "fall back to interrupt mode again\n");
+ uap->im |= UART011_RXIM;
+ pl011_write(uap->im, uap, REG_IMSC);
+ } else {
+#ifdef CONFIG_DMA_ENGINE
+ /* Start Rx DMA poll */
+ if (uap->dmarx.poll_rate) {
+ uap->dmarx.last_jiffies = jiffies;
+ uap->dmarx.last_residue = PL011_DMA_BUFFER_SIZE;
+ mod_timer(&uap->dmarx.timer,
+ jiffies +
+ msecs_to_jiffies(uap->dmarx.poll_rate));
+ }
+#endif
+ }
+ }
+ spin_lock(&uap->port.lock);
+}
+
+static bool pl011_tx_char(struct uart_amba_port *uap, unsigned char c,
+ bool from_irq)
+{
+ if (unlikely(!from_irq) &&
+ pl011_read(uap, REG_FR) & UART01x_FR_TXFF)
+ return false; /* unable to transmit character */
+
+ pl011_write(c, uap, REG_DR);
+ uap->port.icount.tx++;
+
+ return true;
+}
+
+static void pl011_rs485_tx_start(struct uart_amba_port *uap)
+{
+ struct uart_port *port = &uap->port;
+ u32 cr;
+
+ /* Enable transmitter */
+ cr = pl011_read(uap, REG_CR);
+ cr |= UART011_CR_TXE;
+
+ /* Disable receiver if half-duplex */
+ if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
+ cr &= ~UART011_CR_RXE;
+
+ if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
+ cr &= ~UART011_CR_RTS;
+ else
+ cr |= UART011_CR_RTS;
+
+ pl011_write(cr, uap, REG_CR);
+
+ if (port->rs485.delay_rts_before_send)
+ mdelay(port->rs485.delay_rts_before_send);
+
+ uap->rs485_tx_started = true;
+}
+
+/* Returns true if tx interrupts have to be (kept) enabled */
+static bool pl011_tx_chars(struct uart_amba_port *uap, bool from_irq)
+{
+ struct circ_buf *xmit = &uap->port.state->xmit;
+ int count = uap->fifosize >> 1;
+
+ if ((uap->port.rs485.flags & SER_RS485_ENABLED) &&
+ !uap->rs485_tx_started)
+ pl011_rs485_tx_start(uap);
+
+ if (uap->port.x_char) {
+ if (!pl011_tx_char(uap, uap->port.x_char, from_irq))
+ return true;
+ uap->port.x_char = 0;
+ --count;
+ }
+ if (uart_circ_empty(xmit) || uart_tx_stopped(&uap->port)) {
+ pl011_stop_tx(&uap->port);
+ return false;
+ }
+
+ /* If we are using DMA mode, try to send some characters. */
+ if (pl011_dma_tx_irq(uap))
+ return true;
+
+ do {
+ if (likely(from_irq) && count-- == 0)
+ break;
+
+ if (!pl011_tx_char(uap, xmit->buf[xmit->tail], from_irq))
+ break;
+
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ } while (!uart_circ_empty(xmit));
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(&uap->port);
+
+ if (uart_circ_empty(xmit)) {
+ pl011_stop_tx(&uap->port);
+ return false;
+ }
+ return true;
+}
+
+static void pl011_modem_status(struct uart_amba_port *uap)
+{
+ unsigned int status, delta;
+
+ status = pl011_read(uap, REG_FR) & UART01x_FR_MODEM_ANY;
+
+ delta = status ^ uap->old_status;
+ uap->old_status = status;
+
+ if (!delta)
+ return;
+
+ if (delta & UART01x_FR_DCD)
+ uart_handle_dcd_change(&uap->port, status & UART01x_FR_DCD);
+
+ if (delta & uap->vendor->fr_dsr)
+ uap->port.icount.dsr++;
+
+ if (delta & uap->vendor->fr_cts)
+ uart_handle_cts_change(&uap->port,
+ status & uap->vendor->fr_cts);
+
+ wake_up_interruptible(&uap->port.state->port.delta_msr_wait);
+}
+
+static void check_apply_cts_event_workaround(struct uart_amba_port *uap)
+{
+ if (!uap->vendor->cts_event_workaround)
+ return;
+
+ /* workaround to make sure that all bits are unlocked.. */
+ pl011_write(0x00, uap, REG_ICR);
+
+ /*
+ * WA: introduce 26ns(1 uart clk) delay before W1C;
+ * single apb access will incur 2 pclk(133.12Mhz) delay,
+ * so add 2 dummy reads
+ */
+ pl011_read(uap, REG_ICR);
+ pl011_read(uap, REG_ICR);
+}
+
+static irqreturn_t pl011_int(int irq, void *dev_id)
+{
+ struct uart_amba_port *uap = dev_id;
+ unsigned long flags;
+ unsigned int status, pass_counter = AMBA_ISR_PASS_LIMIT;
+ int handled = 0;
+
+ spin_lock_irqsave(&uap->port.lock, flags);
+ status = pl011_read(uap, REG_RIS) & uap->im;
+ if (status) {
+ do {
+ check_apply_cts_event_workaround(uap);
+
+ pl011_write(status & ~(UART011_TXIS|UART011_RTIS|
+ UART011_RXIS),
+ uap, REG_ICR);
+
+ if (status & (UART011_RTIS|UART011_RXIS)) {
+ if (pl011_dma_rx_running(uap))
+ pl011_dma_rx_irq(uap);
+ else
+ pl011_rx_chars(uap);
+ }
+ if (status & (UART011_DSRMIS|UART011_DCDMIS|
+ UART011_CTSMIS|UART011_RIMIS))
+ pl011_modem_status(uap);
+ if (status & UART011_TXIS)
+ pl011_tx_chars(uap, true);
+
+ if (pass_counter-- == 0)
+ break;
+
+ status = pl011_read(uap, REG_RIS) & uap->im;
+ } while (status != 0);
+ handled = 1;
+ }
+
+ spin_unlock_irqrestore(&uap->port.lock, flags);
+
+ return IRQ_RETVAL(handled);
+}
+
+static unsigned int pl011_tx_empty(struct uart_port *port)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+
+ /* Allow feature register bits to be inverted to work around errata */
+ unsigned int status = pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr;
+
+ return status & (uap->vendor->fr_busy | UART01x_FR_TXFF) ?
+ 0 : TIOCSER_TEMT;
+}
+
+static unsigned int pl011_get_mctrl(struct uart_port *port)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+ unsigned int result = 0;
+ unsigned int status = pl011_read(uap, REG_FR);
+
+#define TIOCMBIT(uartbit, tiocmbit) \
+ if (status & uartbit) \
+ result |= tiocmbit
+
+ TIOCMBIT(UART01x_FR_DCD, TIOCM_CAR);
+ TIOCMBIT(uap->vendor->fr_dsr, TIOCM_DSR);
+ TIOCMBIT(uap->vendor->fr_cts, TIOCM_CTS);
+ TIOCMBIT(uap->vendor->fr_ri, TIOCM_RNG);
+#undef TIOCMBIT
+ return result;
+}
+
+static void pl011_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+ unsigned int cr;
+
+ cr = pl011_read(uap, REG_CR);
+
+#define TIOCMBIT(tiocmbit, uartbit) \
+ if (mctrl & tiocmbit) \
+ cr |= uartbit; \
+ else \
+ cr &= ~uartbit
+
+ TIOCMBIT(TIOCM_RTS, UART011_CR_RTS);
+ TIOCMBIT(TIOCM_DTR, UART011_CR_DTR);
+ TIOCMBIT(TIOCM_OUT1, UART011_CR_OUT1);
+ TIOCMBIT(TIOCM_OUT2, UART011_CR_OUT2);
+ TIOCMBIT(TIOCM_LOOP, UART011_CR_LBE);
+
+ if (port->status & UPSTAT_AUTORTS) {
+ /* We need to disable auto-RTS if we want to turn RTS off */
+ TIOCMBIT(TIOCM_RTS, UART011_CR_RTSEN);
+ }
+#undef TIOCMBIT
+
+ pl011_write(cr, uap, REG_CR);
+}
+
+static void pl011_break_ctl(struct uart_port *port, int break_state)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+ unsigned long flags;
+ unsigned int lcr_h;
+
+ spin_lock_irqsave(&uap->port.lock, flags);
+ lcr_h = pl011_read(uap, REG_LCRH_TX);
+ if (break_state == -1)
+ lcr_h |= UART01x_LCRH_BRK;
+ else
+ lcr_h &= ~UART01x_LCRH_BRK;
+ pl011_write(lcr_h, uap, REG_LCRH_TX);
+ spin_unlock_irqrestore(&uap->port.lock, flags);
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+
+static void pl011_quiesce_irqs(struct uart_port *port)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+
+ pl011_write(pl011_read(uap, REG_MIS), uap, REG_ICR);
+ /*
+ * There is no way to clear TXIM as this is "ready to transmit IRQ", so
+ * we simply mask it. start_tx() will unmask it.
+ *
+ * Note we can race with start_tx(), and if the race happens, the
+ * polling user might get another interrupt just after we clear it.
+ * But it should be OK and can happen even w/o the race, e.g.
+ * controller immediately got some new data and raised the IRQ.
+ *
+ * And whoever uses polling routines assumes that it manages the device
+ * (including tx queue), so we're also fine with start_tx()'s caller
+ * side.
+ */
+ pl011_write(pl011_read(uap, REG_IMSC) & ~UART011_TXIM, uap,
+ REG_IMSC);
+}
+
+static int pl011_get_poll_char(struct uart_port *port)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+ unsigned int status;
+
+ /*
+ * The caller might need IRQs lowered, e.g. if used with KDB NMI
+ * debugger.
+ */
+ pl011_quiesce_irqs(port);
+
+ status = pl011_read(uap, REG_FR);
+ if (status & UART01x_FR_RXFE)
+ return NO_POLL_CHAR;
+
+ return pl011_read(uap, REG_DR);
+}
+
+static void pl011_put_poll_char(struct uart_port *port,
+ unsigned char ch)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+
+ while (pl011_read(uap, REG_FR) & UART01x_FR_TXFF)
+ cpu_relax();
+
+ pl011_write(ch, uap, REG_DR);
+}
+
+#endif /* CONFIG_CONSOLE_POLL */
+
+static int pl011_hwinit(struct uart_port *port)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+ int retval;
+
+ /* Optionaly enable pins to be muxed in and configured */
+ pinctrl_pm_select_default_state(port->dev);
+
+ /*
+ * Try to enable the clock producer.
+ */
+ retval = clk_prepare_enable(uap->clk);
+ if (retval)
+ return retval;
+
+ uap->port.uartclk = clk_get_rate(uap->clk);
+
+ /* Clear pending error and receive interrupts */
+ pl011_write(UART011_OEIS | UART011_BEIS | UART011_PEIS |
+ UART011_FEIS | UART011_RTIS | UART011_RXIS,
+ uap, REG_ICR);
+
+ /*
+ * Save interrupts enable mask, and enable RX interrupts in case if
+ * the interrupt is used for NMI entry.
+ */
+ uap->im = pl011_read(uap, REG_IMSC);
+ pl011_write(UART011_RTIM | UART011_RXIM, uap, REG_IMSC);
+
+ if (dev_get_platdata(uap->port.dev)) {
+ struct amba_pl011_data *plat;
+
+ plat = dev_get_platdata(uap->port.dev);
+ if (plat->init)
+ plat->init();
+ }
+ return 0;
+}
+
+static bool pl011_split_lcrh(const struct uart_amba_port *uap)
+{
+ return pl011_reg_to_offset(uap, REG_LCRH_RX) !=
+ pl011_reg_to_offset(uap, REG_LCRH_TX);
+}
+
+static void pl011_write_lcr_h(struct uart_amba_port *uap, unsigned int lcr_h)
+{
+ pl011_write(lcr_h, uap, REG_LCRH_RX);
+ if (pl011_split_lcrh(uap)) {
+ int i;
+ /*
+ * Wait 10 PCLKs before writing LCRH_TX register,
+ * to get this delay write read only register 10 times
+ */
+ for (i = 0; i < 10; ++i)
+ pl011_write(0xff, uap, REG_MIS);
+ pl011_write(lcr_h, uap, REG_LCRH_TX);
+ }
+}
+
+static int pl011_allocate_irq(struct uart_amba_port *uap)
+{
+ pl011_write(uap->im, uap, REG_IMSC);
+
+ return request_irq(uap->port.irq, pl011_int, IRQF_SHARED, "uart-pl011", uap);
+}
+
+/*
+ * Enable interrupts, only timeouts when using DMA
+ * if initial RX DMA job failed, start in interrupt mode
+ * as well.
+ */
+static void pl011_enable_interrupts(struct uart_amba_port *uap)
+{
+ unsigned long flags;
+ unsigned int i;
+
+ spin_lock_irqsave(&uap->port.lock, flags);
+
+ /* Clear out any spuriously appearing RX interrupts */
+ pl011_write(UART011_RTIS | UART011_RXIS, uap, REG_ICR);
+
+ /*
+ * RXIS is asserted only when the RX FIFO transitions from below
+ * to above the trigger threshold. If the RX FIFO is already
+ * full to the threshold this can't happen and RXIS will now be
+ * stuck off. Drain the RX FIFO explicitly to fix this:
+ */
+ for (i = 0; i < uap->fifosize * 2; ++i) {
+ if (pl011_read(uap, REG_FR) & UART01x_FR_RXFE)
+ break;
+
+ pl011_read(uap, REG_DR);
+ }
+
+ uap->im = UART011_RTIM;
+ if (!pl011_dma_rx_running(uap))
+ uap->im |= UART011_RXIM;
+ pl011_write(uap->im, uap, REG_IMSC);
+ spin_unlock_irqrestore(&uap->port.lock, flags);
+}
+
+static void pl011_unthrottle_rx(struct uart_port *port)
+{
+ struct uart_amba_port *uap = container_of(port, struct uart_amba_port, port);
+ unsigned long flags;
+
+ spin_lock_irqsave(&uap->port.lock, flags);
+
+ uap->im = UART011_RTIM;
+ if (!pl011_dma_rx_running(uap))
+ uap->im |= UART011_RXIM;
+
+ pl011_write(uap->im, uap, REG_IMSC);
+
+ spin_unlock_irqrestore(&uap->port.lock, flags);
+}
+
+static int pl011_startup(struct uart_port *port)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+ unsigned int cr;
+ int retval;
+
+ retval = pl011_hwinit(port);
+ if (retval)
+ goto clk_dis;
+
+ retval = pl011_allocate_irq(uap);
+ if (retval)
+ goto clk_dis;
+
+ pl011_write(uap->vendor->ifls, uap, REG_IFLS);
+
+ spin_lock_irq(&uap->port.lock);
+
+ cr = pl011_read(uap, REG_CR);
+ cr &= UART011_CR_RTS | UART011_CR_DTR;
+ cr |= UART01x_CR_UARTEN | UART011_CR_RXE;
+
+ if (!(port->rs485.flags & SER_RS485_ENABLED))
+ cr |= UART011_CR_TXE;
+
+ pl011_write(cr, uap, REG_CR);
+
+ spin_unlock_irq(&uap->port.lock);
+
+ /*
+ * initialise the old status of the modem signals
+ */
+ uap->old_status = pl011_read(uap, REG_FR) & UART01x_FR_MODEM_ANY;
+
+ /* Startup DMA */
+ pl011_dma_startup(uap);
+
+ pl011_enable_interrupts(uap);
+
+ return 0;
+
+ clk_dis:
+ clk_disable_unprepare(uap->clk);
+ return retval;
+}
+
+static int sbsa_uart_startup(struct uart_port *port)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+ int retval;
+
+ retval = pl011_hwinit(port);
+ if (retval)
+ return retval;
+
+ retval = pl011_allocate_irq(uap);
+ if (retval)
+ return retval;
+
+ /* The SBSA UART does not support any modem status lines. */
+ uap->old_status = 0;
+
+ pl011_enable_interrupts(uap);
+
+ return 0;
+}
+
+static void pl011_shutdown_channel(struct uart_amba_port *uap,
+ unsigned int lcrh)
+{
+ unsigned long val;
+
+ val = pl011_read(uap, lcrh);
+ val &= ~(UART01x_LCRH_BRK | UART01x_LCRH_FEN);
+ pl011_write(val, uap, lcrh);
+}
+
+/*
+ * disable the port. It should not disable RTS and DTR.
+ * Also RTS and DTR state should be preserved to restore
+ * it during startup().
+ */
+static void pl011_disable_uart(struct uart_amba_port *uap)
+{
+ unsigned int cr;
+
+ uap->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
+ spin_lock_irq(&uap->port.lock);
+ cr = pl011_read(uap, REG_CR);
+ cr &= UART011_CR_RTS | UART011_CR_DTR;
+ cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
+ pl011_write(cr, uap, REG_CR);
+ spin_unlock_irq(&uap->port.lock);
+
+ /*
+ * disable break condition and fifos
+ */
+ pl011_shutdown_channel(uap, REG_LCRH_RX);
+ if (pl011_split_lcrh(uap))
+ pl011_shutdown_channel(uap, REG_LCRH_TX);
+}
+
+static void pl011_disable_interrupts(struct uart_amba_port *uap)
+{
+ spin_lock_irq(&uap->port.lock);
+
+ /* mask all interrupts and clear all pending ones */
+ uap->im = 0;
+ pl011_write(uap->im, uap, REG_IMSC);
+ pl011_write(0xffff, uap, REG_ICR);
+
+ spin_unlock_irq(&uap->port.lock);
+}
+
+static void pl011_shutdown(struct uart_port *port)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+
+ pl011_disable_interrupts(uap);
+
+ pl011_dma_shutdown(uap);
+
+ if ((port->rs485.flags & SER_RS485_ENABLED) && uap->rs485_tx_started)
+ pl011_rs485_tx_stop(uap);
+
+ free_irq(uap->port.irq, uap);
+
+ pl011_disable_uart(uap);
+
+ /*
+ * Shut down the clock producer
+ */
+ clk_disable_unprepare(uap->clk);
+ /* Optionally let pins go into sleep states */
+ pinctrl_pm_select_sleep_state(port->dev);
+
+ if (dev_get_platdata(uap->port.dev)) {
+ struct amba_pl011_data *plat;
+
+ plat = dev_get_platdata(uap->port.dev);
+ if (plat->exit)
+ plat->exit();
+ }
+
+ if (uap->port.ops->flush_buffer)
+ uap->port.ops->flush_buffer(port);
+}
+
+static void sbsa_uart_shutdown(struct uart_port *port)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+
+ pl011_disable_interrupts(uap);
+
+ free_irq(uap->port.irq, uap);
+
+ if (uap->port.ops->flush_buffer)
+ uap->port.ops->flush_buffer(port);
+}
+
+static void
+pl011_setup_status_masks(struct uart_port *port, struct ktermios *termios)
+{
+ port->read_status_mask = UART011_DR_OE | 255;
+ if (termios->c_iflag & INPCK)
+ port->read_status_mask |= UART011_DR_FE | UART011_DR_PE;
+ if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
+ port->read_status_mask |= UART011_DR_BE;
+
+ /*
+ * Characters to ignore
+ */
+ port->ignore_status_mask = 0;
+ if (termios->c_iflag & IGNPAR)
+ port->ignore_status_mask |= UART011_DR_FE | UART011_DR_PE;
+ if (termios->c_iflag & IGNBRK) {
+ port->ignore_status_mask |= UART011_DR_BE;
+ /*
+ * If we're ignoring parity and break indicators,
+ * ignore overruns too (for real raw support).
+ */
+ if (termios->c_iflag & IGNPAR)
+ port->ignore_status_mask |= UART011_DR_OE;
+ }
+
+ /*
+ * Ignore all characters if CREAD is not set.
+ */
+ if ((termios->c_cflag & CREAD) == 0)
+ port->ignore_status_mask |= UART_DUMMY_DR_RX;
+}
+
+static void
+pl011_set_termios(struct uart_port *port, struct ktermios *termios,
+ const struct ktermios *old)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+ unsigned int lcr_h, old_cr;
+ unsigned long flags;
+ unsigned int baud, quot, clkdiv;
+ unsigned int bits;
+
+ if (uap->vendor->oversampling)
+ clkdiv = 8;
+ else
+ clkdiv = 16;
+
+ /*
+ * Ask the core to calculate the divisor for us.
+ */
+ baud = uart_get_baud_rate(port, termios, old, 0,
+ port->uartclk / clkdiv);
+#ifdef CONFIG_DMA_ENGINE
+ /*
+ * Adjust RX DMA polling rate with baud rate if not specified.
+ */
+ if (uap->dmarx.auto_poll_rate)
+ uap->dmarx.poll_rate = DIV_ROUND_UP(10000000, baud);
+#endif
+
+ if (baud > port->uartclk/16)
+ quot = DIV_ROUND_CLOSEST(port->uartclk * 8, baud);
+ else
+ quot = DIV_ROUND_CLOSEST(port->uartclk * 4, baud);
+
+ switch (termios->c_cflag & CSIZE) {
+ case CS5:
+ lcr_h = UART01x_LCRH_WLEN_5;
+ break;
+ case CS6:
+ lcr_h = UART01x_LCRH_WLEN_6;
+ break;
+ case CS7:
+ lcr_h = UART01x_LCRH_WLEN_7;
+ break;
+ default: // CS8
+ lcr_h = UART01x_LCRH_WLEN_8;
+ break;
+ }
+ if (termios->c_cflag & CSTOPB)
+ lcr_h |= UART01x_LCRH_STP2;
+ if (termios->c_cflag & PARENB) {
+ lcr_h |= UART01x_LCRH_PEN;
+ if (!(termios->c_cflag & PARODD))
+ lcr_h |= UART01x_LCRH_EPS;
+ if (termios->c_cflag & CMSPAR)
+ lcr_h |= UART011_LCRH_SPS;
+ }
+ if (uap->fifosize > 1)
+ lcr_h |= UART01x_LCRH_FEN;
+
+ bits = tty_get_frame_size(termios->c_cflag);
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ /*
+ * Update the per-port timeout.
+ */
+ uart_update_timeout(port, termios->c_cflag, baud);
+
+ /*
+ * Calculate the approximated time it takes to transmit one character
+ * with the given baud rate. We use this as the poll interval when we
+ * wait for the tx queue to empty.
+ */
+ uap->rs485_tx_drain_interval = DIV_ROUND_UP(bits * 1000 * 1000, baud);
+
+ pl011_setup_status_masks(port, termios);
+
+ if (UART_ENABLE_MS(port, termios->c_cflag))
+ pl011_enable_ms(port);
+
+ if (port->rs485.flags & SER_RS485_ENABLED)
+ termios->c_cflag &= ~CRTSCTS;
+
+ old_cr = pl011_read(uap, REG_CR);
+
+ if (termios->c_cflag & CRTSCTS) {
+ if (old_cr & UART011_CR_RTS)
+ old_cr |= UART011_CR_RTSEN;
+
+ old_cr |= UART011_CR_CTSEN;
+ port->status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
+ } else {
+ old_cr &= ~(UART011_CR_CTSEN | UART011_CR_RTSEN);
+ port->status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS);
+ }
+
+ if (uap->vendor->oversampling) {
+ if (baud > port->uartclk / 16)
+ old_cr |= ST_UART011_CR_OVSFACT;
+ else
+ old_cr &= ~ST_UART011_CR_OVSFACT;
+ }
+
+ /*
+ * Workaround for the ST Micro oversampling variants to
+ * increase the bitrate slightly, by lowering the divisor,
+ * to avoid delayed sampling of start bit at high speeds,
+ * else we see data corruption.
+ */
+ if (uap->vendor->oversampling) {
+ if ((baud >= 3000000) && (baud < 3250000) && (quot > 1))
+ quot -= 1;
+ else if ((baud > 3250000) && (quot > 2))
+ quot -= 2;
+ }
+ /* Set baud rate */
+ pl011_write(quot & 0x3f, uap, REG_FBRD);
+ pl011_write(quot >> 6, uap, REG_IBRD);
+
+ /*
+ * ----------v----------v----------v----------v-----
+ * NOTE: REG_LCRH_TX and REG_LCRH_RX MUST BE WRITTEN AFTER
+ * REG_FBRD & REG_IBRD.
+ * ----------^----------^----------^----------^-----
+ */
+ pl011_write_lcr_h(uap, lcr_h);
+ pl011_write(old_cr, uap, REG_CR);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static void
+sbsa_uart_set_termios(struct uart_port *port, struct ktermios *termios,
+ const struct ktermios *old)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+ unsigned long flags;
+
+ tty_termios_encode_baud_rate(termios, uap->fixed_baud, uap->fixed_baud);
+
+ /* The SBSA UART only supports 8n1 without hardware flow control. */
+ termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
+ termios->c_cflag &= ~(CMSPAR | CRTSCTS);
+ termios->c_cflag |= CS8 | CLOCAL;
+
+ spin_lock_irqsave(&port->lock, flags);
+ uart_update_timeout(port, CS8, uap->fixed_baud);
+ pl011_setup_status_masks(port, termios);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+static const char *pl011_type(struct uart_port *port)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+ return uap->port.type == PORT_AMBA ? uap->type : NULL;
+}
+
+/*
+ * Configure/autoconfigure the port.
+ */
+static void pl011_config_port(struct uart_port *port, int flags)
+{
+ if (flags & UART_CONFIG_TYPE)
+ port->type = PORT_AMBA;
+}
+
+/*
+ * verify the new serial_struct (for TIOCSSERIAL).
+ */
+static int pl011_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+ int ret = 0;
+ if (ser->type != PORT_UNKNOWN && ser->type != PORT_AMBA)
+ ret = -EINVAL;
+ if (ser->irq < 0 || ser->irq >= nr_irqs)
+ ret = -EINVAL;
+ if (ser->baud_base < 9600)
+ ret = -EINVAL;
+ if (port->mapbase != (unsigned long) ser->iomem_base)
+ ret = -EINVAL;
+ return ret;
+}
+
+static int pl011_rs485_config(struct uart_port *port, struct ktermios *termios,
+ struct serial_rs485 *rs485)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+
+ if (port->rs485.flags & SER_RS485_ENABLED)
+ pl011_rs485_tx_stop(uap);
+
+ /* Make sure auto RTS is disabled */
+ if (rs485->flags & SER_RS485_ENABLED) {
+ u32 cr = pl011_read(uap, REG_CR);
+
+ cr &= ~UART011_CR_RTSEN;
+ pl011_write(cr, uap, REG_CR);
+ port->status &= ~UPSTAT_AUTORTS;
+ }
+
+ return 0;
+}
+
+static const struct uart_ops amba_pl011_pops = {
+ .tx_empty = pl011_tx_empty,
+ .set_mctrl = pl011_set_mctrl,
+ .get_mctrl = pl011_get_mctrl,
+ .stop_tx = pl011_stop_tx,
+ .start_tx = pl011_start_tx,
+ .stop_rx = pl011_stop_rx,
+ .throttle = pl011_throttle_rx,
+ .unthrottle = pl011_unthrottle_rx,
+ .enable_ms = pl011_enable_ms,
+ .break_ctl = pl011_break_ctl,
+ .startup = pl011_startup,
+ .shutdown = pl011_shutdown,
+ .flush_buffer = pl011_dma_flush_buffer,
+ .set_termios = pl011_set_termios,
+ .type = pl011_type,
+ .config_port = pl011_config_port,
+ .verify_port = pl011_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+ .poll_init = pl011_hwinit,
+ .poll_get_char = pl011_get_poll_char,
+ .poll_put_char = pl011_put_poll_char,
+#endif
+};
+
+static void sbsa_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+}
+
+static unsigned int sbsa_uart_get_mctrl(struct uart_port *port)
+{
+ return 0;
+}
+
+static const struct uart_ops sbsa_uart_pops = {
+ .tx_empty = pl011_tx_empty,
+ .set_mctrl = sbsa_uart_set_mctrl,
+ .get_mctrl = sbsa_uart_get_mctrl,
+ .stop_tx = pl011_stop_tx,
+ .start_tx = pl011_start_tx,
+ .stop_rx = pl011_stop_rx,
+ .startup = sbsa_uart_startup,
+ .shutdown = sbsa_uart_shutdown,
+ .set_termios = sbsa_uart_set_termios,
+ .type = pl011_type,
+ .config_port = pl011_config_port,
+ .verify_port = pl011_verify_port,
+#ifdef CONFIG_CONSOLE_POLL
+ .poll_init = pl011_hwinit,
+ .poll_get_char = pl011_get_poll_char,
+ .poll_put_char = pl011_put_poll_char,
+#endif
+};
+
+static struct uart_amba_port *amba_ports[UART_NR];
+
+#ifdef CONFIG_SERIAL_AMBA_PL011_CONSOLE
+
+static void pl011_console_putchar(struct uart_port *port, unsigned char ch)
+{
+ struct uart_amba_port *uap =
+ container_of(port, struct uart_amba_port, port);
+
+ while (pl011_read(uap, REG_FR) & UART01x_FR_TXFF)
+ cpu_relax();
+ pl011_write(ch, uap, REG_DR);
+}
+
+static void
+pl011_console_write(struct console *co, const char *s, unsigned int count)
+{
+ struct uart_amba_port *uap = amba_ports[co->index];
+ unsigned int old_cr = 0, new_cr;
+ unsigned long flags;
+ int locked = 1;
+
+ clk_enable(uap->clk);
+
+ local_irq_save(flags);
+ if (uap->port.sysrq)
+ locked = 0;
+ else if (oops_in_progress)
+ locked = spin_trylock(&uap->port.lock);
+ else
+ spin_lock(&uap->port.lock);
+
+ /*
+ * First save the CR then disable the interrupts
+ */
+ if (!uap->vendor->always_enabled) {
+ old_cr = pl011_read(uap, REG_CR);
+ new_cr = old_cr & ~UART011_CR_CTSEN;
+ new_cr |= UART01x_CR_UARTEN | UART011_CR_TXE;
+ pl011_write(new_cr, uap, REG_CR);
+ }
+
+ uart_console_write(&uap->port, s, count, pl011_console_putchar);
+
+ /*
+ * Finally, wait for transmitter to become empty and restore the
+ * TCR. Allow feature register bits to be inverted to work around
+ * errata.
+ */
+ while ((pl011_read(uap, REG_FR) ^ uap->vendor->inv_fr)
+ & uap->vendor->fr_busy)
+ cpu_relax();
+ if (!uap->vendor->always_enabled)
+ pl011_write(old_cr, uap, REG_CR);
+
+ if (locked)
+ spin_unlock(&uap->port.lock);
+ local_irq_restore(flags);
+
+ clk_disable(uap->clk);
+}
+
+static void pl011_console_get_options(struct uart_amba_port *uap, int *baud,
+ int *parity, int *bits)
+{
+ if (pl011_read(uap, REG_CR) & UART01x_CR_UARTEN) {
+ unsigned int lcr_h, ibrd, fbrd;
+
+ lcr_h = pl011_read(uap, REG_LCRH_TX);
+
+ *parity = 'n';
+ if (lcr_h & UART01x_LCRH_PEN) {
+ if (lcr_h & UART01x_LCRH_EPS)
+ *parity = 'e';
+ else
+ *parity = 'o';
+ }
+
+ if ((lcr_h & 0x60) == UART01x_LCRH_WLEN_7)
+ *bits = 7;
+ else
+ *bits = 8;
+
+ ibrd = pl011_read(uap, REG_IBRD);
+ fbrd = pl011_read(uap, REG_FBRD);
+
+ *baud = uap->port.uartclk * 4 / (64 * ibrd + fbrd);
+
+ if (uap->vendor->oversampling) {
+ if (pl011_read(uap, REG_CR)
+ & ST_UART011_CR_OVSFACT)
+ *baud *= 2;
+ }
+ }
+}
+
+static int pl011_console_setup(struct console *co, char *options)
+{
+ struct uart_amba_port *uap;
+ int baud = 38400;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+ int ret;
+
+ /*
+ * Check whether an invalid uart number has been specified, and
+ * if so, search for the first available port that does have
+ * console support.
+ */
+ if (co->index >= UART_NR)
+ co->index = 0;
+ uap = amba_ports[co->index];
+ if (!uap)
+ return -ENODEV;
+
+ /* Allow pins to be muxed in and configured */
+ pinctrl_pm_select_default_state(uap->port.dev);
+
+ ret = clk_prepare(uap->clk);
+ if (ret)
+ return ret;
+
+ if (dev_get_platdata(uap->port.dev)) {
+ struct amba_pl011_data *plat;
+
+ plat = dev_get_platdata(uap->port.dev);
+ if (plat->init)
+ plat->init();
+ }
+
+ uap->port.uartclk = clk_get_rate(uap->clk);
+
+ if (uap->vendor->fixed_options) {
+ baud = uap->fixed_baud;
+ } else {
+ if (options)
+ uart_parse_options(options,
+ &baud, &parity, &bits, &flow);
+ else
+ pl011_console_get_options(uap, &baud, &parity, &bits);
+ }
+
+ return uart_set_options(&uap->port, co, baud, parity, bits, flow);
+}
+
+/**
+ * pl011_console_match - non-standard console matching
+ * @co: registering console
+ * @name: name from console command line
+ * @idx: index from console command line
+ * @options: ptr to option string from console command line
+ *
+ * Only attempts to match console command lines of the form:
+ * console=pl011,mmio|mmio32,<addr>[,<options>]
+ * console=pl011,0x<addr>[,<options>]
+ * This form is used to register an initial earlycon boot console and
+ * replace it with the amba_console at pl011 driver init.
+ *
+ * Performs console setup for a match (as required by interface)
+ * If no <options> are specified, then assume the h/w is already setup.
+ *
+ * Returns 0 if console matches; otherwise non-zero to use default matching
+ */
+static int pl011_console_match(struct console *co, char *name, int idx,
+ char *options)
+{
+ unsigned char iotype;
+ resource_size_t addr;
+ int i;
+
+ /*
+ * Systems affected by the Qualcomm Technologies QDF2400 E44 erratum
+ * have a distinct console name, so make sure we check for that.
+ * The actual implementation of the erratum occurs in the probe
+ * function.
+ */
+ if ((strcmp(name, "qdf2400_e44") != 0) && (strcmp(name, "pl011") != 0))
+ return -ENODEV;
+
+ if (uart_parse_earlycon(options, &iotype, &addr, &options))
+ return -ENODEV;
+
+ if (iotype != UPIO_MEM && iotype != UPIO_MEM32)
+ return -ENODEV;
+
+ /* try to match the port specified on the command line */
+ for (i = 0; i < ARRAY_SIZE(amba_ports); i++) {
+ struct uart_port *port;
+
+ if (!amba_ports[i])
+ continue;
+
+ port = &amba_ports[i]->port;
+
+ if (port->mapbase != addr)
+ continue;
+
+ co->index = i;
+ port->cons = co;
+ return pl011_console_setup(co, options);
+ }
+
+ return -ENODEV;
+}
+
+static struct uart_driver amba_reg;
+static struct console amba_console = {
+ .name = "ttyAMA",
+ .write = pl011_console_write,
+ .device = uart_console_device,
+ .setup = pl011_console_setup,
+ .match = pl011_console_match,
+ .flags = CON_PRINTBUFFER | CON_ANYTIME,
+ .index = -1,
+ .data = &amba_reg,
+};
+
+#define AMBA_CONSOLE (&amba_console)
+
+static void qdf2400_e44_putc(struct uart_port *port, unsigned char c)
+{
+ while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
+ cpu_relax();
+ writel(c, port->membase + UART01x_DR);
+ while (!(readl(port->membase + UART01x_FR) & UART011_FR_TXFE))
+ cpu_relax();
+}
+
+static void qdf2400_e44_early_write(struct console *con, const char *s, unsigned n)
+{
+ struct earlycon_device *dev = con->data;
+
+ uart_console_write(&dev->port, s, n, qdf2400_e44_putc);
+}
+
+static void pl011_putc(struct uart_port *port, unsigned char c)
+{
+ while (readl(port->membase + UART01x_FR) & UART01x_FR_TXFF)
+ cpu_relax();
+ if (port->iotype == UPIO_MEM32)
+ writel(c, port->membase + UART01x_DR);
+ else
+ writeb(c, port->membase + UART01x_DR);
+ while (readl(port->membase + UART01x_FR) & UART01x_FR_BUSY)
+ cpu_relax();
+}
+
+static void pl011_early_write(struct console *con, const char *s, unsigned n)
+{
+ struct earlycon_device *dev = con->data;
+
+ uart_console_write(&dev->port, s, n, pl011_putc);
+}
+
+#ifdef CONFIG_CONSOLE_POLL
+static int pl011_getc(struct uart_port *port)
+{
+ if (readl(port->membase + UART01x_FR) & UART01x_FR_RXFE)
+ return NO_POLL_CHAR;
+
+ if (port->iotype == UPIO_MEM32)
+ return readl(port->membase + UART01x_DR);
+ else
+ return readb(port->membase + UART01x_DR);
+}
+
+static int pl011_early_read(struct console *con, char *s, unsigned int n)
+{
+ struct earlycon_device *dev = con->data;
+ int ch, num_read = 0;
+
+ while (num_read < n) {
+ ch = pl011_getc(&dev->port);
+ if (ch == NO_POLL_CHAR)
+ break;
+
+ s[num_read++] = ch;
+ }
+
+ return num_read;
+}
+#else
+#define pl011_early_read NULL
+#endif
+
+/*
+ * On non-ACPI systems, earlycon is enabled by specifying
+ * "earlycon=pl011,<address>" on the kernel command line.
+ *
+ * On ACPI ARM64 systems, an "early" console is enabled via the SPCR table,
+ * by specifying only "earlycon" on the command line. Because it requires
+ * SPCR, the console starts after ACPI is parsed, which is later than a
+ * traditional early console.
+ *
+ * To get the traditional early console that starts before ACPI is parsed,
+ * specify the full "earlycon=pl011,<address>" option.
+ */
+static int __init pl011_early_console_setup(struct earlycon_device *device,
+ const char *opt)
+{
+ if (!device->port.membase)
+ return -ENODEV;
+
+ device->con->write = pl011_early_write;
+ device->con->read = pl011_early_read;
+
+ return 0;
+}
+OF_EARLYCON_DECLARE(pl011, "arm,pl011", pl011_early_console_setup);
+OF_EARLYCON_DECLARE(pl011, "arm,sbsa-uart", pl011_early_console_setup);
+
+/*
+ * On Qualcomm Datacenter Technologies QDF2400 SOCs affected by
+ * Erratum 44, traditional earlycon can be enabled by specifying
+ * "earlycon=qdf2400_e44,<address>". Any options are ignored.
+ *
+ * Alternatively, you can just specify "earlycon", and the early console
+ * will be enabled with the information from the SPCR table. In this
+ * case, the SPCR code will detect the need for the E44 work-around,
+ * and set the console name to "qdf2400_e44".
+ */
+static int __init
+qdf2400_e44_early_console_setup(struct earlycon_device *device,
+ const char *opt)
+{
+ if (!device->port.membase)
+ return -ENODEV;
+
+ device->con->write = qdf2400_e44_early_write;
+ return 0;
+}
+EARLYCON_DECLARE(qdf2400_e44, qdf2400_e44_early_console_setup);
+
+#else
+#define AMBA_CONSOLE NULL
+#endif
+
+static struct uart_driver amba_reg = {
+ .owner = THIS_MODULE,
+ .driver_name = "ttyAMA",
+ .dev_name = "ttyAMA",
+ .major = SERIAL_AMBA_MAJOR,
+ .minor = SERIAL_AMBA_MINOR,
+ .nr = UART_NR,
+ .cons = AMBA_CONSOLE,
+};
+
+static int pl011_probe_dt_alias(int index, struct device *dev)
+{
+ struct device_node *np;
+ static bool seen_dev_with_alias = false;
+ static bool seen_dev_without_alias = false;
+ int ret = index;
+
+ if (!IS_ENABLED(CONFIG_OF))
+ return ret;
+
+ np = dev->of_node;
+ if (!np)
+ return ret;
+
+ ret = of_alias_get_id(np, "serial");
+ if (ret < 0) {
+ seen_dev_without_alias = true;
+ ret = index;
+ } else {
+ seen_dev_with_alias = true;
+ if (ret >= ARRAY_SIZE(amba_ports) || amba_ports[ret] != NULL) {
+ dev_warn(dev, "requested serial port %d not available.\n", ret);
+ ret = index;
+ }
+ }
+
+ if (seen_dev_with_alias && seen_dev_without_alias)
+ dev_warn(dev, "aliased and non-aliased serial devices found in device tree. Serial port enumeration may be unpredictable.\n");
+
+ return ret;
+}
+
+/* unregisters the driver also if no more ports are left */
+static void pl011_unregister_port(struct uart_amba_port *uap)
+{
+ int i;
+ bool busy = false;
+
+ for (i = 0; i < ARRAY_SIZE(amba_ports); i++) {
+ if (amba_ports[i] == uap)
+ amba_ports[i] = NULL;
+ else if (amba_ports[i])
+ busy = true;
+ }
+ pl011_dma_remove(uap);
+ if (!busy)
+ uart_unregister_driver(&amba_reg);
+}
+
+static int pl011_find_free_port(void)
+{
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
+ if (amba_ports[i] == NULL)
+ return i;
+
+ return -EBUSY;
+}
+
+static int pl011_get_rs485_mode(struct uart_amba_port *uap)
+{
+ struct uart_port *port = &uap->port;
+ int ret;
+
+ ret = uart_get_rs485_mode(port);
+ if (ret)
+ return ret;
+
+ return 0;
+}
+
+static int pl011_setup_port(struct device *dev, struct uart_amba_port *uap,
+ struct resource *mmiobase, int index)
+{
+ void __iomem *base;
+ int ret;
+
+ base = devm_ioremap_resource(dev, mmiobase);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ index = pl011_probe_dt_alias(index, dev);
+
+ uap->port.dev = dev;
+ uap->port.mapbase = mmiobase->start;
+ uap->port.membase = base;
+ uap->port.fifosize = uap->fifosize;
+ uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL011_CONSOLE);
+ uap->port.flags = UPF_BOOT_AUTOCONF;
+ uap->port.line = index;
+
+ ret = pl011_get_rs485_mode(uap);
+ if (ret)
+ return ret;
+
+ amba_ports[index] = uap;
+
+ return 0;
+}
+
+static int pl011_register_port(struct uart_amba_port *uap)
+{
+ int ret, i;
+
+ /* Ensure interrupts from this UART are masked and cleared */
+ pl011_write(0, uap, REG_IMSC);
+ pl011_write(0xffff, uap, REG_ICR);
+
+ if (!amba_reg.state) {
+ ret = uart_register_driver(&amba_reg);
+ if (ret < 0) {
+ dev_err(uap->port.dev,
+ "Failed to register AMBA-PL011 driver\n");
+ for (i = 0; i < ARRAY_SIZE(amba_ports); i++)
+ if (amba_ports[i] == uap)
+ amba_ports[i] = NULL;
+ return ret;
+ }
+ }
+
+ ret = uart_add_one_port(&amba_reg, &uap->port);
+ if (ret)
+ pl011_unregister_port(uap);
+
+ return ret;
+}
+
+static const struct serial_rs485 pl011_rs485_supported = {
+ .flags = SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND |
+ SER_RS485_RX_DURING_TX,
+ .delay_rts_before_send = 1,
+ .delay_rts_after_send = 1,
+};
+
+static int pl011_probe(struct amba_device *dev, const struct amba_id *id)
+{
+ struct uart_amba_port *uap;
+ struct vendor_data *vendor = id->data;
+ int portnr, ret;
+ u32 val;
+
+ portnr = pl011_find_free_port();
+ if (portnr < 0)
+ return portnr;
+
+ uap = devm_kzalloc(&dev->dev, sizeof(struct uart_amba_port),
+ GFP_KERNEL);
+ if (!uap)
+ return -ENOMEM;
+
+ uap->clk = devm_clk_get(&dev->dev, NULL);
+ if (IS_ERR(uap->clk))
+ return PTR_ERR(uap->clk);
+
+ uap->reg_offset = vendor->reg_offset;
+ uap->vendor = vendor;
+ uap->fifosize = vendor->get_fifosize(dev);
+ uap->port.iotype = vendor->access_32b ? UPIO_MEM32 : UPIO_MEM;
+ uap->port.irq = dev->irq[0];
+ uap->port.ops = &amba_pl011_pops;
+ uap->port.rs485_config = pl011_rs485_config;
+ uap->port.rs485_supported = pl011_rs485_supported;
+ snprintf(uap->type, sizeof(uap->type), "PL011 rev%u", amba_rev(dev));
+
+ if (device_property_read_u32(&dev->dev, "reg-io-width", &val) == 0) {
+ switch (val) {
+ case 1:
+ uap->port.iotype = UPIO_MEM;
+ break;
+ case 4:
+ uap->port.iotype = UPIO_MEM32;
+ break;
+ default:
+ dev_warn(&dev->dev, "unsupported reg-io-width (%d)\n",
+ val);
+ return -EINVAL;
+ }
+ }
+
+ ret = pl011_setup_port(&dev->dev, uap, &dev->res, portnr);
+ if (ret)
+ return ret;
+
+ amba_set_drvdata(dev, uap);
+
+ return pl011_register_port(uap);
+}
+
+static void pl011_remove(struct amba_device *dev)
+{
+ struct uart_amba_port *uap = amba_get_drvdata(dev);
+
+ uart_remove_one_port(&amba_reg, &uap->port);
+ pl011_unregister_port(uap);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int pl011_suspend(struct device *dev)
+{
+ struct uart_amba_port *uap = dev_get_drvdata(dev);
+
+ if (!uap)
+ return -EINVAL;
+
+ return uart_suspend_port(&amba_reg, &uap->port);
+}
+
+static int pl011_resume(struct device *dev)
+{
+ struct uart_amba_port *uap = dev_get_drvdata(dev);
+
+ if (!uap)
+ return -EINVAL;
+
+ return uart_resume_port(&amba_reg, &uap->port);
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(pl011_dev_pm_ops, pl011_suspend, pl011_resume);
+
+static int sbsa_uart_probe(struct platform_device *pdev)
+{
+ struct uart_amba_port *uap;
+ struct resource *r;
+ int portnr, ret;
+ int baudrate;
+
+ /*
+ * Check the mandatory baud rate parameter in the DT node early
+ * so that we can easily exit with the error.
+ */
+ if (pdev->dev.of_node) {
+ struct device_node *np = pdev->dev.of_node;
+
+ ret = of_property_read_u32(np, "current-speed", &baudrate);
+ if (ret)
+ return ret;
+ } else {
+ baudrate = 115200;
+ }
+
+ portnr = pl011_find_free_port();
+ if (portnr < 0)
+ return portnr;
+
+ uap = devm_kzalloc(&pdev->dev, sizeof(struct uart_amba_port),
+ GFP_KERNEL);
+ if (!uap)
+ return -ENOMEM;
+
+ ret = platform_get_irq(pdev, 0);
+ if (ret < 0)
+ return ret;
+ uap->port.irq = ret;
+
+#ifdef CONFIG_ACPI_SPCR_TABLE
+ if (qdf2400_e44_present) {
+ dev_info(&pdev->dev, "working around QDF2400 SoC erratum 44\n");
+ uap->vendor = &vendor_qdt_qdf2400_e44;
+ } else
+#endif
+ uap->vendor = &vendor_sbsa;
+
+ uap->reg_offset = uap->vendor->reg_offset;
+ uap->fifosize = 32;
+ uap->port.iotype = uap->vendor->access_32b ? UPIO_MEM32 : UPIO_MEM;
+ uap->port.ops = &sbsa_uart_pops;
+ uap->fixed_baud = baudrate;
+
+ snprintf(uap->type, sizeof(uap->type), "SBSA");
+
+ r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ ret = pl011_setup_port(&pdev->dev, uap, r, portnr);
+ if (ret)
+ return ret;
+
+ platform_set_drvdata(pdev, uap);
+
+ return pl011_register_port(uap);
+}
+
+static int sbsa_uart_remove(struct platform_device *pdev)
+{
+ struct uart_amba_port *uap = platform_get_drvdata(pdev);
+
+ uart_remove_one_port(&amba_reg, &uap->port);
+ pl011_unregister_port(uap);
+ return 0;
+}
+
+static const struct of_device_id sbsa_uart_of_match[] = {
+ { .compatible = "arm,sbsa-uart", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, sbsa_uart_of_match);
+
+static const struct acpi_device_id __maybe_unused sbsa_uart_acpi_match[] = {
+ { "ARMH0011", 0 },
+ { "ARMHB000", 0 },
+ {},
+};
+MODULE_DEVICE_TABLE(acpi, sbsa_uart_acpi_match);
+
+static struct platform_driver arm_sbsa_uart_platform_driver = {
+ .probe = sbsa_uart_probe,
+ .remove = sbsa_uart_remove,
+ .driver = {
+ .name = "sbsa-uart",
+ .pm = &pl011_dev_pm_ops,
+ .of_match_table = of_match_ptr(sbsa_uart_of_match),
+ .acpi_match_table = ACPI_PTR(sbsa_uart_acpi_match),
+ .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011),
+ },
+};
+
+static const struct amba_id pl011_ids[] = {
+ {
+ .id = 0x00041011,
+ .mask = 0x000fffff,
+ .data = &vendor_arm,
+ },
+ {
+ .id = 0x00380802,
+ .mask = 0x00ffffff,
+ .data = &vendor_st,
+ },
+ { 0, 0 },
+};
+
+MODULE_DEVICE_TABLE(amba, pl011_ids);
+
+static struct amba_driver pl011_driver = {
+ .drv = {
+ .name = "uart-pl011",
+ .pm = &pl011_dev_pm_ops,
+ .suppress_bind_attrs = IS_BUILTIN(CONFIG_SERIAL_AMBA_PL011),
+ },
+ .id_table = pl011_ids,
+ .probe = pl011_probe,
+ .remove = pl011_remove,
+};
+
+static int __init pl011_init(void)
+{
+ printk(KERN_INFO "Serial: AMBA PL011 UART driver\n");
+
+ if (platform_driver_register(&arm_sbsa_uart_platform_driver))
+ pr_warn("could not register SBSA UART platform driver\n");
+ return amba_driver_register(&pl011_driver);
+}
+
+static void __exit pl011_exit(void)
+{
+ platform_driver_unregister(&arm_sbsa_uart_platform_driver);
+ amba_driver_unregister(&pl011_driver);
+}
+
+/*
+ * While this can be a module, if builtin it's most likely the console
+ * So let's leave module_exit but move module_init to an earlier place
+ */
+arch_initcall(pl011_init);
+module_exit(pl011_exit);
+
+MODULE_AUTHOR("ARM Ltd/Deep Blue Solutions Ltd");
+MODULE_DESCRIPTION("ARM AMBA serial port driver");
+MODULE_LICENSE("GPL");