diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/tty/serial/msm_serial.c | 1926 |
1 files changed, 1926 insertions, 0 deletions
diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c new file mode 100644 index 000000000..7dd19a281 --- /dev/null +++ b/drivers/tty/serial/msm_serial.c @@ -0,0 +1,1926 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Driver for msm7k serial device and console + * + * Copyright (C) 2007 Google, Inc. + * Author: Robert Love <rlove@google.com> + * Copyright (c) 2011, Code Aurora Forum. All rights reserved. + */ + +#include <linux/kernel.h> +#include <linux/atomic.h> +#include <linux/dma/qcom_adm.h> +#include <linux/dma-mapping.h> +#include <linux/dmaengine.h> +#include <linux/module.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/interrupt.h> +#include <linux/init.h> +#include <linux/console.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/serial_core.h> +#include <linux/slab.h> +#include <linux/clk.h> +#include <linux/platform_device.h> +#include <linux/delay.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/wait.h> + +#define MSM_UART_MR1 0x0000 + +#define MSM_UART_MR1_AUTO_RFR_LEVEL0 0x3F +#define MSM_UART_MR1_AUTO_RFR_LEVEL1 0x3FF00 +#define MSM_UART_DM_MR1_AUTO_RFR_LEVEL1 0xFFFFFF00 +#define MSM_UART_MR1_RX_RDY_CTL BIT(7) +#define MSM_UART_MR1_CTS_CTL BIT(6) + +#define MSM_UART_MR2 0x0004 +#define MSM_UART_MR2_ERROR_MODE BIT(6) +#define MSM_UART_MR2_BITS_PER_CHAR 0x30 +#define MSM_UART_MR2_BITS_PER_CHAR_5 (0x0 << 4) +#define MSM_UART_MR2_BITS_PER_CHAR_6 (0x1 << 4) +#define MSM_UART_MR2_BITS_PER_CHAR_7 (0x2 << 4) +#define MSM_UART_MR2_BITS_PER_CHAR_8 (0x3 << 4) +#define MSM_UART_MR2_STOP_BIT_LEN_ONE (0x1 << 2) +#define MSM_UART_MR2_STOP_BIT_LEN_TWO (0x3 << 2) +#define MSM_UART_MR2_PARITY_MODE_NONE 0x0 +#define MSM_UART_MR2_PARITY_MODE_ODD 0x1 +#define MSM_UART_MR2_PARITY_MODE_EVEN 0x2 +#define MSM_UART_MR2_PARITY_MODE_SPACE 0x3 +#define MSM_UART_MR2_PARITY_MODE 0x3 + +#define MSM_UART_CSR 0x0008 + +#define MSM_UART_TF 0x000C +#define UARTDM_TF 0x0070 + +#define MSM_UART_CR 0x0010 +#define MSM_UART_CR_CMD_NULL (0 << 4) +#define MSM_UART_CR_CMD_RESET_RX (1 << 4) +#define MSM_UART_CR_CMD_RESET_TX (2 << 4) +#define MSM_UART_CR_CMD_RESET_ERR (3 << 4) +#define MSM_UART_CR_CMD_RESET_BREAK_INT (4 << 4) +#define MSM_UART_CR_CMD_START_BREAK (5 << 4) +#define MSM_UART_CR_CMD_STOP_BREAK (6 << 4) +#define MSM_UART_CR_CMD_RESET_CTS (7 << 4) +#define MSM_UART_CR_CMD_RESET_STALE_INT (8 << 4) +#define MSM_UART_CR_CMD_PACKET_MODE (9 << 4) +#define MSM_UART_CR_CMD_MODE_RESET (12 << 4) +#define MSM_UART_CR_CMD_SET_RFR (13 << 4) +#define MSM_UART_CR_CMD_RESET_RFR (14 << 4) +#define MSM_UART_CR_CMD_PROTECTION_EN (16 << 4) +#define MSM_UART_CR_CMD_STALE_EVENT_DISABLE (6 << 8) +#define MSM_UART_CR_CMD_STALE_EVENT_ENABLE (80 << 4) +#define MSM_UART_CR_CMD_FORCE_STALE (4 << 8) +#define MSM_UART_CR_CMD_RESET_TX_READY (3 << 8) +#define MSM_UART_CR_TX_DISABLE BIT(3) +#define MSM_UART_CR_TX_ENABLE BIT(2) +#define MSM_UART_CR_RX_DISABLE BIT(1) +#define MSM_UART_CR_RX_ENABLE BIT(0) +#define MSM_UART_CR_CMD_RESET_RXBREAK_START ((1 << 11) | (2 << 4)) + +#define MSM_UART_IMR 0x0014 +#define MSM_UART_IMR_TXLEV BIT(0) +#define MSM_UART_IMR_RXSTALE BIT(3) +#define MSM_UART_IMR_RXLEV BIT(4) +#define MSM_UART_IMR_DELTA_CTS BIT(5) +#define MSM_UART_IMR_CURRENT_CTS BIT(6) +#define MSM_UART_IMR_RXBREAK_START BIT(10) + +#define MSM_UART_IPR_RXSTALE_LAST 0x20 +#define MSM_UART_IPR_STALE_LSB 0x1F +#define MSM_UART_IPR_STALE_TIMEOUT_MSB 0x3FF80 +#define MSM_UART_DM_IPR_STALE_TIMEOUT_MSB 0xFFFFFF80 + +#define MSM_UART_IPR 0x0018 +#define MSM_UART_TFWR 0x001C +#define MSM_UART_RFWR 0x0020 +#define MSM_UART_HCR 0x0024 + +#define MSM_UART_MREG 0x0028 +#define MSM_UART_NREG 0x002C +#define MSM_UART_DREG 0x0030 +#define MSM_UART_MNDREG 0x0034 +#define MSM_UART_IRDA 0x0038 +#define MSM_UART_MISR_MODE 0x0040 +#define MSM_UART_MISR_RESET 0x0044 +#define MSM_UART_MISR_EXPORT 0x0048 +#define MSM_UART_MISR_VAL 0x004C +#define MSM_UART_TEST_CTRL 0x0050 + +#define MSM_UART_SR 0x0008 +#define MSM_UART_SR_HUNT_CHAR BIT(7) +#define MSM_UART_SR_RX_BREAK BIT(6) +#define MSM_UART_SR_PAR_FRAME_ERR BIT(5) +#define MSM_UART_SR_OVERRUN BIT(4) +#define MSM_UART_SR_TX_EMPTY BIT(3) +#define MSM_UART_SR_TX_READY BIT(2) +#define MSM_UART_SR_RX_FULL BIT(1) +#define MSM_UART_SR_RX_READY BIT(0) + +#define MSM_UART_RF 0x000C +#define UARTDM_RF 0x0070 +#define MSM_UART_MISR 0x0010 +#define MSM_UART_ISR 0x0014 +#define MSM_UART_ISR_TX_READY BIT(7) + +#define UARTDM_RXFS 0x50 +#define UARTDM_RXFS_BUF_SHIFT 0x7 +#define UARTDM_RXFS_BUF_MASK 0x7 + +#define UARTDM_DMEN 0x3C +#define UARTDM_DMEN_RX_SC_ENABLE BIT(5) +#define UARTDM_DMEN_TX_SC_ENABLE BIT(4) + +#define UARTDM_DMEN_TX_BAM_ENABLE BIT(2) /* UARTDM_1P4 */ +#define UARTDM_DMEN_TX_DM_ENABLE BIT(0) /* < UARTDM_1P4 */ + +#define UARTDM_DMEN_RX_BAM_ENABLE BIT(3) /* UARTDM_1P4 */ +#define UARTDM_DMEN_RX_DM_ENABLE BIT(1) /* < UARTDM_1P4 */ + +#define UARTDM_DMRX 0x34 +#define UARTDM_NCF_TX 0x40 +#define UARTDM_RX_TOTAL_SNAP 0x38 + +#define UARTDM_BURST_SIZE 16 /* in bytes */ +#define UARTDM_TX_AIGN(x) ((x) & ~0x3) /* valid for > 1p3 */ +#define UARTDM_TX_MAX 256 /* in bytes, valid for <= 1p3 */ +#define UARTDM_RX_SIZE (UART_XMIT_SIZE / 4) + +enum { + UARTDM_1P1 = 1, + UARTDM_1P2, + UARTDM_1P3, + UARTDM_1P4, +}; + +struct msm_dma { + struct dma_chan *chan; + enum dma_data_direction dir; + dma_addr_t phys; + unsigned char *virt; + dma_cookie_t cookie; + u32 enable_bit; + unsigned int count; + struct dma_async_tx_descriptor *desc; +}; + +struct msm_port { + struct uart_port uart; + char name[16]; + struct clk *clk; + struct clk *pclk; + unsigned int imr; + int is_uartdm; + unsigned int old_snap_state; + bool break_detected; + struct msm_dma tx_dma; + struct msm_dma rx_dma; +}; + +static inline struct msm_port *to_msm_port(struct uart_port *up) +{ + return container_of(up, struct msm_port, uart); +} + +static +void msm_write(struct uart_port *port, unsigned int val, unsigned int off) +{ + writel_relaxed(val, port->membase + off); +} + +static +unsigned int msm_read(struct uart_port *port, unsigned int off) +{ + return readl_relaxed(port->membase + off); +} + +/* + * Setup the MND registers to use the TCXO clock. + */ +static void msm_serial_set_mnd_regs_tcxo(struct uart_port *port) +{ + msm_write(port, 0x06, MSM_UART_MREG); + msm_write(port, 0xF1, MSM_UART_NREG); + msm_write(port, 0x0F, MSM_UART_DREG); + msm_write(port, 0x1A, MSM_UART_MNDREG); + port->uartclk = 1843200; +} + +/* + * Setup the MND registers to use the TCXO clock divided by 4. + */ +static void msm_serial_set_mnd_regs_tcxoby4(struct uart_port *port) +{ + msm_write(port, 0x18, MSM_UART_MREG); + msm_write(port, 0xF6, MSM_UART_NREG); + msm_write(port, 0x0F, MSM_UART_DREG); + msm_write(port, 0x0A, MSM_UART_MNDREG); + port->uartclk = 1843200; +} + +static void msm_serial_set_mnd_regs(struct uart_port *port) +{ + struct msm_port *msm_port = to_msm_port(port); + + /* + * These registers don't exist so we change the clk input rate + * on uartdm hardware instead + */ + if (msm_port->is_uartdm) + return; + + if (port->uartclk == 19200000) + msm_serial_set_mnd_regs_tcxo(port); + else if (port->uartclk == 4800000) + msm_serial_set_mnd_regs_tcxoby4(port); +} + +static void msm_handle_tx(struct uart_port *port); +static void msm_start_rx_dma(struct msm_port *msm_port); + +static void msm_stop_dma(struct uart_port *port, struct msm_dma *dma) +{ + struct device *dev = port->dev; + unsigned int mapped; + u32 val; + + mapped = dma->count; + dma->count = 0; + + dmaengine_terminate_all(dma->chan); + + /* + * DMA Stall happens if enqueue and flush command happens concurrently. + * For example before changing the baud rate/protocol configuration and + * sending flush command to ADM, disable the channel of UARTDM. + * Note: should not reset the receiver here immediately as it is not + * suggested to do disable/reset or reset/disable at the same time. + */ + val = msm_read(port, UARTDM_DMEN); + val &= ~dma->enable_bit; + msm_write(port, val, UARTDM_DMEN); + + if (mapped) + dma_unmap_single(dev, dma->phys, mapped, dma->dir); +} + +static void msm_release_dma(struct msm_port *msm_port) +{ + struct msm_dma *dma; + + dma = &msm_port->tx_dma; + if (dma->chan) { + msm_stop_dma(&msm_port->uart, dma); + dma_release_channel(dma->chan); + } + + memset(dma, 0, sizeof(*dma)); + + dma = &msm_port->rx_dma; + if (dma->chan) { + msm_stop_dma(&msm_port->uart, dma); + dma_release_channel(dma->chan); + kfree(dma->virt); + } + + memset(dma, 0, sizeof(*dma)); +} + +static void msm_request_tx_dma(struct msm_port *msm_port, resource_size_t base) +{ + struct device *dev = msm_port->uart.dev; + struct dma_slave_config conf; + struct qcom_adm_peripheral_config periph_conf = {}; + struct msm_dma *dma; + u32 crci = 0; + int ret; + + dma = &msm_port->tx_dma; + + /* allocate DMA resources, if available */ + dma->chan = dma_request_chan(dev, "tx"); + if (IS_ERR(dma->chan)) + goto no_tx; + + of_property_read_u32(dev->of_node, "qcom,tx-crci", &crci); + + memset(&conf, 0, sizeof(conf)); + conf.direction = DMA_MEM_TO_DEV; + conf.device_fc = true; + conf.dst_addr = base + UARTDM_TF; + conf.dst_maxburst = UARTDM_BURST_SIZE; + if (crci) { + conf.peripheral_config = &periph_conf; + conf.peripheral_size = sizeof(periph_conf); + periph_conf.crci = crci; + } + + ret = dmaengine_slave_config(dma->chan, &conf); + if (ret) + goto rel_tx; + + dma->dir = DMA_TO_DEVICE; + + if (msm_port->is_uartdm < UARTDM_1P4) + dma->enable_bit = UARTDM_DMEN_TX_DM_ENABLE; + else + dma->enable_bit = UARTDM_DMEN_TX_BAM_ENABLE; + + return; + +rel_tx: + dma_release_channel(dma->chan); +no_tx: + memset(dma, 0, sizeof(*dma)); +} + +static void msm_request_rx_dma(struct msm_port *msm_port, resource_size_t base) +{ + struct device *dev = msm_port->uart.dev; + struct dma_slave_config conf; + struct qcom_adm_peripheral_config periph_conf = {}; + struct msm_dma *dma; + u32 crci = 0; + int ret; + + dma = &msm_port->rx_dma; + + /* allocate DMA resources, if available */ + dma->chan = dma_request_chan(dev, "rx"); + if (IS_ERR(dma->chan)) + goto no_rx; + + of_property_read_u32(dev->of_node, "qcom,rx-crci", &crci); + + dma->virt = kzalloc(UARTDM_RX_SIZE, GFP_KERNEL); + if (!dma->virt) + goto rel_rx; + + memset(&conf, 0, sizeof(conf)); + conf.direction = DMA_DEV_TO_MEM; + conf.device_fc = true; + conf.src_addr = base + UARTDM_RF; + conf.src_maxburst = UARTDM_BURST_SIZE; + if (crci) { + conf.peripheral_config = &periph_conf; + conf.peripheral_size = sizeof(periph_conf); + periph_conf.crci = crci; + } + + ret = dmaengine_slave_config(dma->chan, &conf); + if (ret) + goto err; + + dma->dir = DMA_FROM_DEVICE; + + if (msm_port->is_uartdm < UARTDM_1P4) + dma->enable_bit = UARTDM_DMEN_RX_DM_ENABLE; + else + dma->enable_bit = UARTDM_DMEN_RX_BAM_ENABLE; + + return; +err: + kfree(dma->virt); +rel_rx: + dma_release_channel(dma->chan); +no_rx: + memset(dma, 0, sizeof(*dma)); +} + +static inline void msm_wait_for_xmitr(struct uart_port *port) +{ + unsigned int timeout = 500000; + + while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_EMPTY)) { + if (msm_read(port, MSM_UART_ISR) & MSM_UART_ISR_TX_READY) + break; + udelay(1); + if (!timeout--) + break; + } + msm_write(port, MSM_UART_CR_CMD_RESET_TX_READY, MSM_UART_CR); +} + +static void msm_stop_tx(struct uart_port *port) +{ + struct msm_port *msm_port = to_msm_port(port); + + msm_port->imr &= ~MSM_UART_IMR_TXLEV; + msm_write(port, msm_port->imr, MSM_UART_IMR); +} + +static void msm_start_tx(struct uart_port *port) +{ + struct msm_port *msm_port = to_msm_port(port); + struct msm_dma *dma = &msm_port->tx_dma; + + /* Already started in DMA mode */ + if (dma->count) + return; + + msm_port->imr |= MSM_UART_IMR_TXLEV; + msm_write(port, msm_port->imr, MSM_UART_IMR); +} + +static void msm_reset_dm_count(struct uart_port *port, int count) +{ + msm_wait_for_xmitr(port); + msm_write(port, count, UARTDM_NCF_TX); + msm_read(port, UARTDM_NCF_TX); +} + +static void msm_complete_tx_dma(void *args) +{ + struct msm_port *msm_port = args; + struct uart_port *port = &msm_port->uart; + struct circ_buf *xmit = &port->state->xmit; + struct msm_dma *dma = &msm_port->tx_dma; + struct dma_tx_state state; + unsigned long flags; + unsigned int count; + u32 val; + + spin_lock_irqsave(&port->lock, flags); + + /* Already stopped */ + if (!dma->count) + goto done; + + dmaengine_tx_status(dma->chan, dma->cookie, &state); + + dma_unmap_single(port->dev, dma->phys, dma->count, dma->dir); + + val = msm_read(port, UARTDM_DMEN); + val &= ~dma->enable_bit; + msm_write(port, val, UARTDM_DMEN); + + if (msm_port->is_uartdm > UARTDM_1P3) { + msm_write(port, MSM_UART_CR_CMD_RESET_TX, MSM_UART_CR); + msm_write(port, MSM_UART_CR_TX_ENABLE, MSM_UART_CR); + } + + count = dma->count - state.residue; + port->icount.tx += count; + dma->count = 0; + + xmit->tail += count; + xmit->tail &= UART_XMIT_SIZE - 1; + + /* Restore "Tx FIFO below watermark" interrupt */ + msm_port->imr |= MSM_UART_IMR_TXLEV; + msm_write(port, msm_port->imr, MSM_UART_IMR); + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + + msm_handle_tx(port); +done: + spin_unlock_irqrestore(&port->lock, flags); +} + +static int msm_handle_tx_dma(struct msm_port *msm_port, unsigned int count) +{ + struct circ_buf *xmit = &msm_port->uart.state->xmit; + struct uart_port *port = &msm_port->uart; + struct msm_dma *dma = &msm_port->tx_dma; + void *cpu_addr; + int ret; + u32 val; + + cpu_addr = &xmit->buf[xmit->tail]; + + dma->phys = dma_map_single(port->dev, cpu_addr, count, dma->dir); + ret = dma_mapping_error(port->dev, dma->phys); + if (ret) + return ret; + + dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys, + count, DMA_MEM_TO_DEV, + DMA_PREP_INTERRUPT | + DMA_PREP_FENCE); + if (!dma->desc) { + ret = -EIO; + goto unmap; + } + + dma->desc->callback = msm_complete_tx_dma; + dma->desc->callback_param = msm_port; + + dma->cookie = dmaengine_submit(dma->desc); + ret = dma_submit_error(dma->cookie); + if (ret) + goto unmap; + + /* + * Using DMA complete for Tx FIFO reload, no need for + * "Tx FIFO below watermark" one, disable it + */ + msm_port->imr &= ~MSM_UART_IMR_TXLEV; + msm_write(port, msm_port->imr, MSM_UART_IMR); + + dma->count = count; + + val = msm_read(port, UARTDM_DMEN); + val |= dma->enable_bit; + + if (msm_port->is_uartdm < UARTDM_1P4) + msm_write(port, val, UARTDM_DMEN); + + msm_reset_dm_count(port, count); + + if (msm_port->is_uartdm > UARTDM_1P3) + msm_write(port, val, UARTDM_DMEN); + + dma_async_issue_pending(dma->chan); + return 0; +unmap: + dma_unmap_single(port->dev, dma->phys, count, dma->dir); + return ret; +} + +static void msm_complete_rx_dma(void *args) +{ + struct msm_port *msm_port = args; + struct uart_port *port = &msm_port->uart; + struct tty_port *tport = &port->state->port; + struct msm_dma *dma = &msm_port->rx_dma; + int count = 0, i, sysrq; + unsigned long flags; + u32 val; + + spin_lock_irqsave(&port->lock, flags); + + /* Already stopped */ + if (!dma->count) + goto done; + + val = msm_read(port, UARTDM_DMEN); + val &= ~dma->enable_bit; + msm_write(port, val, UARTDM_DMEN); + + if (msm_read(port, MSM_UART_SR) & MSM_UART_SR_OVERRUN) { + port->icount.overrun++; + tty_insert_flip_char(tport, 0, TTY_OVERRUN); + msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR); + } + + count = msm_read(port, UARTDM_RX_TOTAL_SNAP); + + port->icount.rx += count; + + dma->count = 0; + + dma_unmap_single(port->dev, dma->phys, UARTDM_RX_SIZE, dma->dir); + + for (i = 0; i < count; i++) { + char flag = TTY_NORMAL; + + if (msm_port->break_detected && dma->virt[i] == 0) { + port->icount.brk++; + flag = TTY_BREAK; + msm_port->break_detected = false; + if (uart_handle_break(port)) + continue; + } + + if (!(port->read_status_mask & MSM_UART_SR_RX_BREAK)) + flag = TTY_NORMAL; + + spin_unlock_irqrestore(&port->lock, flags); + sysrq = uart_handle_sysrq_char(port, dma->virt[i]); + spin_lock_irqsave(&port->lock, flags); + if (!sysrq) + tty_insert_flip_char(tport, dma->virt[i], flag); + } + + msm_start_rx_dma(msm_port); +done: + spin_unlock_irqrestore(&port->lock, flags); + + if (count) + tty_flip_buffer_push(tport); +} + +static void msm_start_rx_dma(struct msm_port *msm_port) +{ + struct msm_dma *dma = &msm_port->rx_dma; + struct uart_port *uart = &msm_port->uart; + u32 val; + int ret; + + if (IS_ENABLED(CONFIG_CONSOLE_POLL)) + return; + + if (!dma->chan) + return; + + dma->phys = dma_map_single(uart->dev, dma->virt, + UARTDM_RX_SIZE, dma->dir); + ret = dma_mapping_error(uart->dev, dma->phys); + if (ret) + goto sw_mode; + + dma->desc = dmaengine_prep_slave_single(dma->chan, dma->phys, + UARTDM_RX_SIZE, DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT); + if (!dma->desc) + goto unmap; + + dma->desc->callback = msm_complete_rx_dma; + dma->desc->callback_param = msm_port; + + dma->cookie = dmaengine_submit(dma->desc); + ret = dma_submit_error(dma->cookie); + if (ret) + goto unmap; + /* + * Using DMA for FIFO off-load, no need for "Rx FIFO over + * watermark" or "stale" interrupts, disable them + */ + msm_port->imr &= ~(MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE); + + /* + * Well, when DMA is ADM3 engine(implied by <= UARTDM v1.3), + * we need RXSTALE to flush input DMA fifo to memory + */ + if (msm_port->is_uartdm < UARTDM_1P4) + msm_port->imr |= MSM_UART_IMR_RXSTALE; + + msm_write(uart, msm_port->imr, MSM_UART_IMR); + + dma->count = UARTDM_RX_SIZE; + + dma_async_issue_pending(dma->chan); + + msm_write(uart, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR); + msm_write(uart, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR); + + val = msm_read(uart, UARTDM_DMEN); + val |= dma->enable_bit; + + if (msm_port->is_uartdm < UARTDM_1P4) + msm_write(uart, val, UARTDM_DMEN); + + msm_write(uart, UARTDM_RX_SIZE, UARTDM_DMRX); + + if (msm_port->is_uartdm > UARTDM_1P3) + msm_write(uart, val, UARTDM_DMEN); + + return; +unmap: + dma_unmap_single(uart->dev, dma->phys, UARTDM_RX_SIZE, dma->dir); + +sw_mode: + /* + * Switch from DMA to SW/FIFO mode. After clearing Rx BAM (UARTDM_DMEN), + * receiver must be reset. + */ + msm_write(uart, MSM_UART_CR_CMD_RESET_RX, MSM_UART_CR); + msm_write(uart, MSM_UART_CR_RX_ENABLE, MSM_UART_CR); + + msm_write(uart, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR); + msm_write(uart, 0xFFFFFF, UARTDM_DMRX); + msm_write(uart, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR); + + /* Re-enable RX interrupts */ + msm_port->imr |= MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE; + msm_write(uart, msm_port->imr, MSM_UART_IMR); +} + +static void msm_stop_rx(struct uart_port *port) +{ + struct msm_port *msm_port = to_msm_port(port); + struct msm_dma *dma = &msm_port->rx_dma; + + msm_port->imr &= ~(MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE); + msm_write(port, msm_port->imr, MSM_UART_IMR); + + if (dma->chan) + msm_stop_dma(port, dma); +} + +static void msm_enable_ms(struct uart_port *port) +{ + struct msm_port *msm_port = to_msm_port(port); + + msm_port->imr |= MSM_UART_IMR_DELTA_CTS; + msm_write(port, msm_port->imr, MSM_UART_IMR); +} + +static void msm_handle_rx_dm(struct uart_port *port, unsigned int misr) + __must_hold(&port->lock) +{ + struct tty_port *tport = &port->state->port; + unsigned int sr; + int count = 0; + struct msm_port *msm_port = to_msm_port(port); + + if ((msm_read(port, MSM_UART_SR) & MSM_UART_SR_OVERRUN)) { + port->icount.overrun++; + tty_insert_flip_char(tport, 0, TTY_OVERRUN); + msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR); + } + + if (misr & MSM_UART_IMR_RXSTALE) { + count = msm_read(port, UARTDM_RX_TOTAL_SNAP) - + msm_port->old_snap_state; + msm_port->old_snap_state = 0; + } else { + count = 4 * (msm_read(port, MSM_UART_RFWR)); + msm_port->old_snap_state += count; + } + + /* TODO: Precise error reporting */ + + port->icount.rx += count; + + while (count > 0) { + unsigned char buf[4]; + int sysrq, r_count, i; + + sr = msm_read(port, MSM_UART_SR); + if ((sr & MSM_UART_SR_RX_READY) == 0) { + msm_port->old_snap_state -= count; + break; + } + + ioread32_rep(port->membase + UARTDM_RF, buf, 1); + r_count = min_t(int, count, sizeof(buf)); + + for (i = 0; i < r_count; i++) { + char flag = TTY_NORMAL; + + if (msm_port->break_detected && buf[i] == 0) { + port->icount.brk++; + flag = TTY_BREAK; + msm_port->break_detected = false; + if (uart_handle_break(port)) + continue; + } + + if (!(port->read_status_mask & MSM_UART_SR_RX_BREAK)) + flag = TTY_NORMAL; + + spin_unlock(&port->lock); + sysrq = uart_handle_sysrq_char(port, buf[i]); + spin_lock(&port->lock); + if (!sysrq) + tty_insert_flip_char(tport, buf[i], flag); + } + count -= r_count; + } + + tty_flip_buffer_push(tport); + + if (misr & (MSM_UART_IMR_RXSTALE)) + msm_write(port, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR); + msm_write(port, 0xFFFFFF, UARTDM_DMRX); + msm_write(port, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR); + + /* Try to use DMA */ + msm_start_rx_dma(msm_port); +} + +static void msm_handle_rx(struct uart_port *port) + __must_hold(&port->lock) +{ + struct tty_port *tport = &port->state->port; + unsigned int sr; + + /* + * Handle overrun. My understanding of the hardware is that overrun + * is not tied to the RX buffer, so we handle the case out of band. + */ + if ((msm_read(port, MSM_UART_SR) & MSM_UART_SR_OVERRUN)) { + port->icount.overrun++; + tty_insert_flip_char(tport, 0, TTY_OVERRUN); + msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR); + } + + /* and now the main RX loop */ + while ((sr = msm_read(port, MSM_UART_SR)) & MSM_UART_SR_RX_READY) { + unsigned int c; + char flag = TTY_NORMAL; + int sysrq; + + c = msm_read(port, MSM_UART_RF); + + if (sr & MSM_UART_SR_RX_BREAK) { + port->icount.brk++; + if (uart_handle_break(port)) + continue; + } else if (sr & MSM_UART_SR_PAR_FRAME_ERR) { + port->icount.frame++; + } else { + port->icount.rx++; + } + + /* Mask conditions we're ignorning. */ + sr &= port->read_status_mask; + + if (sr & MSM_UART_SR_RX_BREAK) + flag = TTY_BREAK; + else if (sr & MSM_UART_SR_PAR_FRAME_ERR) + flag = TTY_FRAME; + + spin_unlock(&port->lock); + sysrq = uart_handle_sysrq_char(port, c); + spin_lock(&port->lock); + if (!sysrq) + tty_insert_flip_char(tport, c, flag); + } + + tty_flip_buffer_push(tport); +} + +static void msm_handle_tx_pio(struct uart_port *port, unsigned int tx_count) +{ + struct circ_buf *xmit = &port->state->xmit; + struct msm_port *msm_port = to_msm_port(port); + unsigned int num_chars; + unsigned int tf_pointer = 0; + void __iomem *tf; + + if (msm_port->is_uartdm) + tf = port->membase + UARTDM_TF; + else + tf = port->membase + MSM_UART_TF; + + if (tx_count && msm_port->is_uartdm) + msm_reset_dm_count(port, tx_count); + + while (tf_pointer < tx_count) { + int i; + char buf[4] = { 0 }; + + if (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY)) + break; + + if (msm_port->is_uartdm) + num_chars = min(tx_count - tf_pointer, + (unsigned int)sizeof(buf)); + else + num_chars = 1; + + for (i = 0; i < num_chars; i++) { + buf[i] = xmit->buf[xmit->tail + i]; + port->icount.tx++; + } + + iowrite32_rep(tf, buf, 1); + xmit->tail = (xmit->tail + num_chars) & (UART_XMIT_SIZE - 1); + tf_pointer += num_chars; + } + + /* disable tx interrupts if nothing more to send */ + if (uart_circ_empty(xmit)) + msm_stop_tx(port); + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); +} + +static void msm_handle_tx(struct uart_port *port) +{ + struct msm_port *msm_port = to_msm_port(port); + struct circ_buf *xmit = &msm_port->uart.state->xmit; + struct msm_dma *dma = &msm_port->tx_dma; + unsigned int pio_count, dma_count, dma_min; + char buf[4] = { 0 }; + void __iomem *tf; + int err = 0; + + if (port->x_char) { + if (msm_port->is_uartdm) + tf = port->membase + UARTDM_TF; + else + tf = port->membase + MSM_UART_TF; + + buf[0] = port->x_char; + + if (msm_port->is_uartdm) + msm_reset_dm_count(port, 1); + + iowrite32_rep(tf, buf, 1); + port->icount.tx++; + port->x_char = 0; + return; + } + + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { + msm_stop_tx(port); + return; + } + + pio_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); + dma_count = CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE); + + dma_min = 1; /* Always DMA */ + if (msm_port->is_uartdm > UARTDM_1P3) { + dma_count = UARTDM_TX_AIGN(dma_count); + dma_min = UARTDM_BURST_SIZE; + } else { + if (dma_count > UARTDM_TX_MAX) + dma_count = UARTDM_TX_MAX; + } + + if (pio_count > port->fifosize) + pio_count = port->fifosize; + + if (!dma->chan || dma_count < dma_min) + msm_handle_tx_pio(port, pio_count); + else + err = msm_handle_tx_dma(msm_port, dma_count); + + if (err) /* fall back to PIO mode */ + msm_handle_tx_pio(port, pio_count); +} + +static void msm_handle_delta_cts(struct uart_port *port) +{ + msm_write(port, MSM_UART_CR_CMD_RESET_CTS, MSM_UART_CR); + port->icount.cts++; + wake_up_interruptible(&port->state->port.delta_msr_wait); +} + +static irqreturn_t msm_uart_irq(int irq, void *dev_id) +{ + struct uart_port *port = dev_id; + struct msm_port *msm_port = to_msm_port(port); + struct msm_dma *dma = &msm_port->rx_dma; + unsigned long flags; + unsigned int misr; + u32 val; + + spin_lock_irqsave(&port->lock, flags); + misr = msm_read(port, MSM_UART_MISR); + msm_write(port, 0, MSM_UART_IMR); /* disable interrupt */ + + if (misr & MSM_UART_IMR_RXBREAK_START) { + msm_port->break_detected = true; + msm_write(port, MSM_UART_CR_CMD_RESET_RXBREAK_START, MSM_UART_CR); + } + + if (misr & (MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE)) { + if (dma->count) { + val = MSM_UART_CR_CMD_STALE_EVENT_DISABLE; + msm_write(port, val, MSM_UART_CR); + val = MSM_UART_CR_CMD_RESET_STALE_INT; + msm_write(port, val, MSM_UART_CR); + /* + * Flush DMA input fifo to memory, this will also + * trigger DMA RX completion + */ + dmaengine_terminate_all(dma->chan); + } else if (msm_port->is_uartdm) { + msm_handle_rx_dm(port, misr); + } else { + msm_handle_rx(port); + } + } + if (misr & MSM_UART_IMR_TXLEV) + msm_handle_tx(port); + if (misr & MSM_UART_IMR_DELTA_CTS) + msm_handle_delta_cts(port); + + msm_write(port, msm_port->imr, MSM_UART_IMR); /* restore interrupt */ + spin_unlock_irqrestore(&port->lock, flags); + + return IRQ_HANDLED; +} + +static unsigned int msm_tx_empty(struct uart_port *port) +{ + return (msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_EMPTY) ? TIOCSER_TEMT : 0; +} + +static unsigned int msm_get_mctrl(struct uart_port *port) +{ + return TIOCM_CAR | TIOCM_CTS | TIOCM_DSR | TIOCM_RTS; +} + +static void msm_reset(struct uart_port *port) +{ + struct msm_port *msm_port = to_msm_port(port); + unsigned int mr; + + /* reset everything */ + msm_write(port, MSM_UART_CR_CMD_RESET_RX, MSM_UART_CR); + msm_write(port, MSM_UART_CR_CMD_RESET_TX, MSM_UART_CR); + msm_write(port, MSM_UART_CR_CMD_RESET_ERR, MSM_UART_CR); + msm_write(port, MSM_UART_CR_CMD_RESET_BREAK_INT, MSM_UART_CR); + msm_write(port, MSM_UART_CR_CMD_RESET_CTS, MSM_UART_CR); + msm_write(port, MSM_UART_CR_CMD_RESET_RFR, MSM_UART_CR); + mr = msm_read(port, MSM_UART_MR1); + mr &= ~MSM_UART_MR1_RX_RDY_CTL; + msm_write(port, mr, MSM_UART_MR1); + + /* Disable DM modes */ + if (msm_port->is_uartdm) + msm_write(port, 0, UARTDM_DMEN); +} + +static void msm_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + unsigned int mr; + + mr = msm_read(port, MSM_UART_MR1); + + if (!(mctrl & TIOCM_RTS)) { + mr &= ~MSM_UART_MR1_RX_RDY_CTL; + msm_write(port, mr, MSM_UART_MR1); + msm_write(port, MSM_UART_CR_CMD_RESET_RFR, MSM_UART_CR); + } else { + mr |= MSM_UART_MR1_RX_RDY_CTL; + msm_write(port, mr, MSM_UART_MR1); + } +} + +static void msm_break_ctl(struct uart_port *port, int break_ctl) +{ + if (break_ctl) + msm_write(port, MSM_UART_CR_CMD_START_BREAK, MSM_UART_CR); + else + msm_write(port, MSM_UART_CR_CMD_STOP_BREAK, MSM_UART_CR); +} + +struct msm_baud_map { + u16 divisor; + u8 code; + u8 rxstale; +}; + +static const struct msm_baud_map * +msm_find_best_baud(struct uart_port *port, unsigned int baud, + unsigned long *rate) +{ + struct msm_port *msm_port = to_msm_port(port); + unsigned int divisor, result; + unsigned long target, old, best_rate = 0, diff, best_diff = ULONG_MAX; + const struct msm_baud_map *entry, *end, *best; + static const struct msm_baud_map table[] = { + { 1, 0xff, 31 }, + { 2, 0xee, 16 }, + { 3, 0xdd, 8 }, + { 4, 0xcc, 6 }, + { 6, 0xbb, 6 }, + { 8, 0xaa, 6 }, + { 12, 0x99, 6 }, + { 16, 0x88, 1 }, + { 24, 0x77, 1 }, + { 32, 0x66, 1 }, + { 48, 0x55, 1 }, + { 96, 0x44, 1 }, + { 192, 0x33, 1 }, + { 384, 0x22, 1 }, + { 768, 0x11, 1 }, + { 1536, 0x00, 1 }, + }; + + best = table; /* Default to smallest divider */ + target = clk_round_rate(msm_port->clk, 16 * baud); + divisor = DIV_ROUND_CLOSEST(target, 16 * baud); + + end = table + ARRAY_SIZE(table); + entry = table; + while (entry < end) { + if (entry->divisor <= divisor) { + result = target / entry->divisor / 16; + diff = abs(result - baud); + + /* Keep track of best entry */ + if (diff < best_diff) { + best_diff = diff; + best = entry; + best_rate = target; + } + + if (result == baud) + break; + } else if (entry->divisor > divisor) { + old = target; + target = clk_round_rate(msm_port->clk, old + 1); + /* + * The rate didn't get any faster so we can't do + * better at dividing it down + */ + if (target == old) + break; + + /* Start the divisor search over at this new rate */ + entry = table; + divisor = DIV_ROUND_CLOSEST(target, 16 * baud); + continue; + } + entry++; + } + + *rate = best_rate; + return best; +} + +static int msm_set_baud_rate(struct uart_port *port, unsigned int baud, + unsigned long *saved_flags) +{ + unsigned int rxstale, watermark, mask; + struct msm_port *msm_port = to_msm_port(port); + const struct msm_baud_map *entry; + unsigned long flags, rate; + + flags = *saved_flags; + spin_unlock_irqrestore(&port->lock, flags); + + entry = msm_find_best_baud(port, baud, &rate); + clk_set_rate(msm_port->clk, rate); + baud = rate / 16 / entry->divisor; + + spin_lock_irqsave(&port->lock, flags); + *saved_flags = flags; + port->uartclk = rate; + + msm_write(port, entry->code, MSM_UART_CSR); + + /* RX stale watermark */ + rxstale = entry->rxstale; + watermark = MSM_UART_IPR_STALE_LSB & rxstale; + if (msm_port->is_uartdm) { + mask = MSM_UART_DM_IPR_STALE_TIMEOUT_MSB; + } else { + watermark |= MSM_UART_IPR_RXSTALE_LAST; + mask = MSM_UART_IPR_STALE_TIMEOUT_MSB; + } + + watermark |= mask & (rxstale << 2); + + msm_write(port, watermark, MSM_UART_IPR); + + /* set RX watermark */ + watermark = (port->fifosize * 3) / 4; + msm_write(port, watermark, MSM_UART_RFWR); + + /* set TX watermark */ + msm_write(port, 10, MSM_UART_TFWR); + + msm_write(port, MSM_UART_CR_CMD_PROTECTION_EN, MSM_UART_CR); + msm_reset(port); + + /* Enable RX and TX */ + msm_write(port, MSM_UART_CR_TX_ENABLE | MSM_UART_CR_RX_ENABLE, MSM_UART_CR); + + /* turn on RX and CTS interrupts */ + msm_port->imr = MSM_UART_IMR_RXLEV | MSM_UART_IMR_RXSTALE | + MSM_UART_IMR_CURRENT_CTS | MSM_UART_IMR_RXBREAK_START; + + msm_write(port, msm_port->imr, MSM_UART_IMR); + + if (msm_port->is_uartdm) { + msm_write(port, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR); + msm_write(port, 0xFFFFFF, UARTDM_DMRX); + msm_write(port, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR); + } + + return baud; +} + +static void msm_init_clock(struct uart_port *port) +{ + struct msm_port *msm_port = to_msm_port(port); + + clk_prepare_enable(msm_port->clk); + clk_prepare_enable(msm_port->pclk); + msm_serial_set_mnd_regs(port); +} + +static int msm_startup(struct uart_port *port) +{ + struct msm_port *msm_port = to_msm_port(port); + unsigned int data, rfr_level, mask; + int ret; + + snprintf(msm_port->name, sizeof(msm_port->name), + "msm_serial%d", port->line); + + msm_init_clock(port); + + if (likely(port->fifosize > 12)) + rfr_level = port->fifosize - 12; + else + rfr_level = port->fifosize; + + /* set automatic RFR level */ + data = msm_read(port, MSM_UART_MR1); + + if (msm_port->is_uartdm) + mask = MSM_UART_DM_MR1_AUTO_RFR_LEVEL1; + else + mask = MSM_UART_MR1_AUTO_RFR_LEVEL1; + + data &= ~mask; + data &= ~MSM_UART_MR1_AUTO_RFR_LEVEL0; + data |= mask & (rfr_level << 2); + data |= MSM_UART_MR1_AUTO_RFR_LEVEL0 & rfr_level; + msm_write(port, data, MSM_UART_MR1); + + if (msm_port->is_uartdm) { + msm_request_tx_dma(msm_port, msm_port->uart.mapbase); + msm_request_rx_dma(msm_port, msm_port->uart.mapbase); + } + + ret = request_irq(port->irq, msm_uart_irq, IRQF_TRIGGER_HIGH, + msm_port->name, port); + if (unlikely(ret)) + goto err_irq; + + return 0; + +err_irq: + if (msm_port->is_uartdm) + msm_release_dma(msm_port); + + clk_disable_unprepare(msm_port->pclk); + clk_disable_unprepare(msm_port->clk); + + return ret; +} + +static void msm_shutdown(struct uart_port *port) +{ + struct msm_port *msm_port = to_msm_port(port); + + msm_port->imr = 0; + msm_write(port, 0, MSM_UART_IMR); /* disable interrupts */ + + if (msm_port->is_uartdm) + msm_release_dma(msm_port); + + clk_disable_unprepare(msm_port->clk); + + free_irq(port->irq, port); +} + +static void msm_set_termios(struct uart_port *port, struct ktermios *termios, + const struct ktermios *old) +{ + struct msm_port *msm_port = to_msm_port(port); + struct msm_dma *dma = &msm_port->rx_dma; + unsigned long flags; + unsigned int baud, mr; + + spin_lock_irqsave(&port->lock, flags); + + if (dma->chan) /* Terminate if any */ + msm_stop_dma(port, dma); + + /* calculate and set baud rate */ + baud = uart_get_baud_rate(port, termios, old, 300, 4000000); + baud = msm_set_baud_rate(port, baud, &flags); + if (tty_termios_baud_rate(termios)) + tty_termios_encode_baud_rate(termios, baud, baud); + + /* calculate parity */ + mr = msm_read(port, MSM_UART_MR2); + mr &= ~MSM_UART_MR2_PARITY_MODE; + if (termios->c_cflag & PARENB) { + if (termios->c_cflag & PARODD) + mr |= MSM_UART_MR2_PARITY_MODE_ODD; + else if (termios->c_cflag & CMSPAR) + mr |= MSM_UART_MR2_PARITY_MODE_SPACE; + else + mr |= MSM_UART_MR2_PARITY_MODE_EVEN; + } + + /* calculate bits per char */ + mr &= ~MSM_UART_MR2_BITS_PER_CHAR; + switch (termios->c_cflag & CSIZE) { + case CS5: + mr |= MSM_UART_MR2_BITS_PER_CHAR_5; + break; + case CS6: + mr |= MSM_UART_MR2_BITS_PER_CHAR_6; + break; + case CS7: + mr |= MSM_UART_MR2_BITS_PER_CHAR_7; + break; + case CS8: + default: + mr |= MSM_UART_MR2_BITS_PER_CHAR_8; + break; + } + + /* calculate stop bits */ + mr &= ~(MSM_UART_MR2_STOP_BIT_LEN_ONE | MSM_UART_MR2_STOP_BIT_LEN_TWO); + if (termios->c_cflag & CSTOPB) + mr |= MSM_UART_MR2_STOP_BIT_LEN_TWO; + else + mr |= MSM_UART_MR2_STOP_BIT_LEN_ONE; + + /* set parity, bits per char, and stop bit */ + msm_write(port, mr, MSM_UART_MR2); + + /* calculate and set hardware flow control */ + mr = msm_read(port, MSM_UART_MR1); + mr &= ~(MSM_UART_MR1_CTS_CTL | MSM_UART_MR1_RX_RDY_CTL); + if (termios->c_cflag & CRTSCTS) { + mr |= MSM_UART_MR1_CTS_CTL; + mr |= MSM_UART_MR1_RX_RDY_CTL; + } + msm_write(port, mr, MSM_UART_MR1); + + /* Configure status bits to ignore based on termio flags. */ + port->read_status_mask = 0; + if (termios->c_iflag & INPCK) + port->read_status_mask |= MSM_UART_SR_PAR_FRAME_ERR; + if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) + port->read_status_mask |= MSM_UART_SR_RX_BREAK; + + uart_update_timeout(port, termios->c_cflag, baud); + + /* Try to use DMA */ + msm_start_rx_dma(msm_port); + + spin_unlock_irqrestore(&port->lock, flags); +} + +static const char *msm_type(struct uart_port *port) +{ + return "MSM"; +} + +static void msm_release_port(struct uart_port *port) +{ + struct platform_device *pdev = to_platform_device(port->dev); + struct resource *uart_resource; + resource_size_t size; + + uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (unlikely(!uart_resource)) + return; + size = resource_size(uart_resource); + + release_mem_region(port->mapbase, size); + iounmap(port->membase); + port->membase = NULL; +} + +static int msm_request_port(struct uart_port *port) +{ + struct platform_device *pdev = to_platform_device(port->dev); + struct resource *uart_resource; + resource_size_t size; + int ret; + + uart_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (unlikely(!uart_resource)) + return -ENXIO; + + size = resource_size(uart_resource); + + if (!request_mem_region(port->mapbase, size, "msm_serial")) + return -EBUSY; + + port->membase = ioremap(port->mapbase, size); + if (!port->membase) { + ret = -EBUSY; + goto fail_release_port; + } + + return 0; + +fail_release_port: + release_mem_region(port->mapbase, size); + return ret; +} + +static void msm_config_port(struct uart_port *port, int flags) +{ + int ret; + + if (flags & UART_CONFIG_TYPE) { + port->type = PORT_MSM; + ret = msm_request_port(port); + if (ret) + return; + } +} + +static int msm_verify_port(struct uart_port *port, struct serial_struct *ser) +{ + if (unlikely(ser->type != PORT_UNKNOWN && ser->type != PORT_MSM)) + return -EINVAL; + if (unlikely(port->irq != ser->irq)) + return -EINVAL; + return 0; +} + +static void msm_power(struct uart_port *port, unsigned int state, + unsigned int oldstate) +{ + struct msm_port *msm_port = to_msm_port(port); + + switch (state) { + case 0: + clk_prepare_enable(msm_port->clk); + clk_prepare_enable(msm_port->pclk); + break; + case 3: + clk_disable_unprepare(msm_port->clk); + clk_disable_unprepare(msm_port->pclk); + break; + default: + pr_err("msm_serial: Unknown PM state %d\n", state); + } +} + +#ifdef CONFIG_CONSOLE_POLL +static int msm_poll_get_char_single(struct uart_port *port) +{ + struct msm_port *msm_port = to_msm_port(port); + unsigned int rf_reg = msm_port->is_uartdm ? UARTDM_RF : MSM_UART_RF; + + if (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_RX_READY)) + return NO_POLL_CHAR; + + return msm_read(port, rf_reg) & 0xff; +} + +static int msm_poll_get_char_dm(struct uart_port *port) +{ + int c; + static u32 slop; + static int count; + unsigned char *sp = (unsigned char *)&slop; + + /* Check if a previous read had more than one char */ + if (count) { + c = sp[sizeof(slop) - count]; + count--; + /* Or if FIFO is empty */ + } else if (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_RX_READY)) { + /* + * If RX packing buffer has less than a word, force stale to + * push contents into RX FIFO + */ + count = msm_read(port, UARTDM_RXFS); + count = (count >> UARTDM_RXFS_BUF_SHIFT) & UARTDM_RXFS_BUF_MASK; + if (count) { + msm_write(port, MSM_UART_CR_CMD_FORCE_STALE, MSM_UART_CR); + slop = msm_read(port, UARTDM_RF); + c = sp[0]; + count--; + msm_write(port, MSM_UART_CR_CMD_RESET_STALE_INT, MSM_UART_CR); + msm_write(port, 0xFFFFFF, UARTDM_DMRX); + msm_write(port, MSM_UART_CR_CMD_STALE_EVENT_ENABLE, MSM_UART_CR); + } else { + c = NO_POLL_CHAR; + } + /* FIFO has a word */ + } else { + slop = msm_read(port, UARTDM_RF); + c = sp[0]; + count = sizeof(slop) - 1; + } + + return c; +} + +static int msm_poll_get_char(struct uart_port *port) +{ + u32 imr; + int c; + struct msm_port *msm_port = to_msm_port(port); + + /* Disable all interrupts */ + imr = msm_read(port, MSM_UART_IMR); + msm_write(port, 0, MSM_UART_IMR); + + if (msm_port->is_uartdm) + c = msm_poll_get_char_dm(port); + else + c = msm_poll_get_char_single(port); + + /* Enable interrupts */ + msm_write(port, imr, MSM_UART_IMR); + + return c; +} + +static void msm_poll_put_char(struct uart_port *port, unsigned char c) +{ + u32 imr; + struct msm_port *msm_port = to_msm_port(port); + + /* Disable all interrupts */ + imr = msm_read(port, MSM_UART_IMR); + msm_write(port, 0, MSM_UART_IMR); + + if (msm_port->is_uartdm) + msm_reset_dm_count(port, 1); + + /* Wait until FIFO is empty */ + while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY)) + cpu_relax(); + + /* Write a character */ + msm_write(port, c, msm_port->is_uartdm ? UARTDM_TF : MSM_UART_TF); + + /* Wait until FIFO is empty */ + while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY)) + cpu_relax(); + + /* Enable interrupts */ + msm_write(port, imr, MSM_UART_IMR); +} +#endif + +static const struct uart_ops msm_uart_pops = { + .tx_empty = msm_tx_empty, + .set_mctrl = msm_set_mctrl, + .get_mctrl = msm_get_mctrl, + .stop_tx = msm_stop_tx, + .start_tx = msm_start_tx, + .stop_rx = msm_stop_rx, + .enable_ms = msm_enable_ms, + .break_ctl = msm_break_ctl, + .startup = msm_startup, + .shutdown = msm_shutdown, + .set_termios = msm_set_termios, + .type = msm_type, + .release_port = msm_release_port, + .request_port = msm_request_port, + .config_port = msm_config_port, + .verify_port = msm_verify_port, + .pm = msm_power, +#ifdef CONFIG_CONSOLE_POLL + .poll_get_char = msm_poll_get_char, + .poll_put_char = msm_poll_put_char, +#endif +}; + +static struct msm_port msm_uart_ports[] = { + { + .uart = { + .iotype = UPIO_MEM, + .ops = &msm_uart_pops, + .flags = UPF_BOOT_AUTOCONF, + .fifosize = 64, + .line = 0, + }, + }, + { + .uart = { + .iotype = UPIO_MEM, + .ops = &msm_uart_pops, + .flags = UPF_BOOT_AUTOCONF, + .fifosize = 64, + .line = 1, + }, + }, + { + .uart = { + .iotype = UPIO_MEM, + .ops = &msm_uart_pops, + .flags = UPF_BOOT_AUTOCONF, + .fifosize = 64, + .line = 2, + }, + }, +}; + +#define MSM_UART_NR ARRAY_SIZE(msm_uart_ports) + +static inline struct uart_port *msm_get_port_from_line(unsigned int line) +{ + return &msm_uart_ports[line].uart; +} + +#ifdef CONFIG_SERIAL_MSM_CONSOLE +static void __msm_console_write(struct uart_port *port, const char *s, + unsigned int count, bool is_uartdm) +{ + unsigned long flags; + int i; + int num_newlines = 0; + bool replaced = false; + void __iomem *tf; + int locked = 1; + + if (is_uartdm) + tf = port->membase + UARTDM_TF; + else + tf = port->membase + MSM_UART_TF; + + /* Account for newlines that will get a carriage return added */ + for (i = 0; i < count; i++) + if (s[i] == '\n') + num_newlines++; + count += num_newlines; + + local_irq_save(flags); + + if (port->sysrq) + locked = 0; + else if (oops_in_progress) + locked = spin_trylock(&port->lock); + else + spin_lock(&port->lock); + + if (is_uartdm) + msm_reset_dm_count(port, count); + + i = 0; + while (i < count) { + int j; + unsigned int num_chars; + char buf[4] = { 0 }; + + if (is_uartdm) + num_chars = min(count - i, (unsigned int)sizeof(buf)); + else + num_chars = 1; + + for (j = 0; j < num_chars; j++) { + char c = *s; + + if (c == '\n' && !replaced) { + buf[j] = '\r'; + j++; + replaced = true; + } + if (j < num_chars) { + buf[j] = c; + s++; + replaced = false; + } + } + + while (!(msm_read(port, MSM_UART_SR) & MSM_UART_SR_TX_READY)) + cpu_relax(); + + iowrite32_rep(tf, buf, 1); + i += num_chars; + } + + if (locked) + spin_unlock(&port->lock); + + local_irq_restore(flags); +} + +static void msm_console_write(struct console *co, const char *s, + unsigned int count) +{ + struct uart_port *port; + struct msm_port *msm_port; + + BUG_ON(co->index < 0 || co->index >= MSM_UART_NR); + + port = msm_get_port_from_line(co->index); + msm_port = to_msm_port(port); + + __msm_console_write(port, s, count, msm_port->is_uartdm); +} + +static int msm_console_setup(struct console *co, char *options) +{ + struct uart_port *port; + int baud = 115200; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + + if (unlikely(co->index >= MSM_UART_NR || co->index < 0)) + return -ENXIO; + + port = msm_get_port_from_line(co->index); + + if (unlikely(!port->membase)) + return -ENXIO; + + msm_init_clock(port); + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + + pr_info("msm_serial: console setup on port #%d\n", port->line); + + return uart_set_options(port, co, baud, parity, bits, flow); +} + +static void +msm_serial_early_write(struct console *con, const char *s, unsigned n) +{ + struct earlycon_device *dev = con->data; + + __msm_console_write(&dev->port, s, n, false); +} + +static int __init +msm_serial_early_console_setup(struct earlycon_device *device, const char *opt) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = msm_serial_early_write; + return 0; +} +OF_EARLYCON_DECLARE(msm_serial, "qcom,msm-uart", + msm_serial_early_console_setup); + +static void +msm_serial_early_write_dm(struct console *con, const char *s, unsigned n) +{ + struct earlycon_device *dev = con->data; + + __msm_console_write(&dev->port, s, n, true); +} + +static int __init +msm_serial_early_console_setup_dm(struct earlycon_device *device, + const char *opt) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = msm_serial_early_write_dm; + return 0; +} +OF_EARLYCON_DECLARE(msm_serial_dm, "qcom,msm-uartdm", + msm_serial_early_console_setup_dm); + +static struct uart_driver msm_uart_driver; + +static struct console msm_console = { + .name = "ttyMSM", + .write = msm_console_write, + .device = uart_console_device, + .setup = msm_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &msm_uart_driver, +}; + +#define MSM_CONSOLE (&msm_console) + +#else +#define MSM_CONSOLE NULL +#endif + +static struct uart_driver msm_uart_driver = { + .owner = THIS_MODULE, + .driver_name = "msm_serial", + .dev_name = "ttyMSM", + .nr = MSM_UART_NR, + .cons = MSM_CONSOLE, +}; + +static atomic_t msm_uart_next_id = ATOMIC_INIT(0); + +static const struct of_device_id msm_uartdm_table[] = { + { .compatible = "qcom,msm-uartdm-v1.1", .data = (void *)UARTDM_1P1 }, + { .compatible = "qcom,msm-uartdm-v1.2", .data = (void *)UARTDM_1P2 }, + { .compatible = "qcom,msm-uartdm-v1.3", .data = (void *)UARTDM_1P3 }, + { .compatible = "qcom,msm-uartdm-v1.4", .data = (void *)UARTDM_1P4 }, + { } +}; + +static int msm_serial_probe(struct platform_device *pdev) +{ + struct msm_port *msm_port; + struct resource *resource; + struct uart_port *port; + const struct of_device_id *id; + int irq, line; + + if (pdev->dev.of_node) + line = of_alias_get_id(pdev->dev.of_node, "serial"); + else + line = pdev->id; + + if (line < 0) + line = atomic_inc_return(&msm_uart_next_id) - 1; + + if (unlikely(line < 0 || line >= MSM_UART_NR)) + return -ENXIO; + + dev_info(&pdev->dev, "msm_serial: detected port #%d\n", line); + + port = msm_get_port_from_line(line); + port->dev = &pdev->dev; + msm_port = to_msm_port(port); + + id = of_match_device(msm_uartdm_table, &pdev->dev); + if (id) + msm_port->is_uartdm = (unsigned long)id->data; + else + msm_port->is_uartdm = 0; + + msm_port->clk = devm_clk_get(&pdev->dev, "core"); + if (IS_ERR(msm_port->clk)) + return PTR_ERR(msm_port->clk); + + if (msm_port->is_uartdm) { + msm_port->pclk = devm_clk_get(&pdev->dev, "iface"); + if (IS_ERR(msm_port->pclk)) + return PTR_ERR(msm_port->pclk); + } + + port->uartclk = clk_get_rate(msm_port->clk); + dev_info(&pdev->dev, "uartclk = %d\n", port->uartclk); + + resource = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (unlikely(!resource)) + return -ENXIO; + port->mapbase = resource->start; + + irq = platform_get_irq(pdev, 0); + if (unlikely(irq < 0)) + return -ENXIO; + port->irq = irq; + port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_MSM_CONSOLE); + + platform_set_drvdata(pdev, port); + + return uart_add_one_port(&msm_uart_driver, port); +} + +static int msm_serial_remove(struct platform_device *pdev) +{ + struct uart_port *port = platform_get_drvdata(pdev); + + uart_remove_one_port(&msm_uart_driver, port); + + return 0; +} + +static const struct of_device_id msm_match_table[] = { + { .compatible = "qcom,msm-uart" }, + { .compatible = "qcom,msm-uartdm" }, + {} +}; +MODULE_DEVICE_TABLE(of, msm_match_table); + +static int __maybe_unused msm_serial_suspend(struct device *dev) +{ + struct msm_port *port = dev_get_drvdata(dev); + + uart_suspend_port(&msm_uart_driver, &port->uart); + + return 0; +} + +static int __maybe_unused msm_serial_resume(struct device *dev) +{ + struct msm_port *port = dev_get_drvdata(dev); + + uart_resume_port(&msm_uart_driver, &port->uart); + + return 0; +} + +static const struct dev_pm_ops msm_serial_dev_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(msm_serial_suspend, msm_serial_resume) +}; + +static struct platform_driver msm_platform_driver = { + .remove = msm_serial_remove, + .probe = msm_serial_probe, + .driver = { + .name = "msm_serial", + .pm = &msm_serial_dev_pm_ops, + .of_match_table = msm_match_table, + }, +}; + +static int __init msm_serial_init(void) +{ + int ret; + + ret = uart_register_driver(&msm_uart_driver); + if (unlikely(ret)) + return ret; + + ret = platform_driver_register(&msm_platform_driver); + if (unlikely(ret)) + uart_unregister_driver(&msm_uart_driver); + + pr_info("msm_serial: driver initialized\n"); + + return ret; +} + +static void __exit msm_serial_exit(void) +{ + platform_driver_unregister(&msm_platform_driver); + uart_unregister_driver(&msm_uart_driver); +} + +module_init(msm_serial_init); +module_exit(msm_serial_exit); + +MODULE_AUTHOR("Robert Love <rlove@google.com>"); +MODULE_DESCRIPTION("Driver for msm7x serial device"); +MODULE_LICENSE("GPL"); |