summaryrefslogtreecommitdiffstats
path: root/drivers/tty/serial/bcm63xx_uart.c
diff options
context:
space:
mode:
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/bcm63xx_uart.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/bcm63xx_uart.c')
-rw-r--r--drivers/tty/serial/bcm63xx_uart.c921
1 files changed, 921 insertions, 0 deletions
diff --git a/drivers/tty/serial/bcm63xx_uart.c b/drivers/tty/serial/bcm63xx_uart.c
new file mode 100644
index 000000000..5d9737c2d
--- /dev/null
+++ b/drivers/tty/serial/bcm63xx_uart.c
@@ -0,0 +1,921 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Derived from many drivers using generic_serial interface.
+ *
+ * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
+ *
+ * Serial driver for BCM63xx integrated UART.
+ *
+ * Hardware flow control was _not_ tested since I only have RX/TX on
+ * my board.
+ */
+
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/console.h>
+#include <linux/clk.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/sysrq.h>
+#include <linux/serial.h>
+#include <linux/serial_core.h>
+#include <linux/serial_bcm63xx.h>
+#include <linux/io.h>
+#include <linux/of.h>
+
+#define BCM63XX_NR_UARTS 2
+
+static struct uart_port ports[BCM63XX_NR_UARTS];
+
+/*
+ * rx interrupt mask / stat
+ *
+ * mask:
+ * - rx fifo full
+ * - rx fifo above threshold
+ * - rx fifo not empty for too long
+ */
+#define UART_RX_INT_MASK (UART_IR_MASK(UART_IR_RXOVER) | \
+ UART_IR_MASK(UART_IR_RXTHRESH) | \
+ UART_IR_MASK(UART_IR_RXTIMEOUT))
+
+#define UART_RX_INT_STAT (UART_IR_STAT(UART_IR_RXOVER) | \
+ UART_IR_STAT(UART_IR_RXTHRESH) | \
+ UART_IR_STAT(UART_IR_RXTIMEOUT))
+
+/*
+ * tx interrupt mask / stat
+ *
+ * mask:
+ * - tx fifo empty
+ * - tx fifo below threshold
+ */
+#define UART_TX_INT_MASK (UART_IR_MASK(UART_IR_TXEMPTY) | \
+ UART_IR_MASK(UART_IR_TXTRESH))
+
+#define UART_TX_INT_STAT (UART_IR_STAT(UART_IR_TXEMPTY) | \
+ UART_IR_STAT(UART_IR_TXTRESH))
+
+/*
+ * external input interrupt
+ *
+ * mask: any edge on CTS, DCD
+ */
+#define UART_EXTINP_INT_MASK (UART_EXTINP_IRMASK(UART_EXTINP_IR_CTS) | \
+ UART_EXTINP_IRMASK(UART_EXTINP_IR_DCD))
+
+/*
+ * handy uart register accessor
+ */
+static inline unsigned int bcm_uart_readl(struct uart_port *port,
+ unsigned int offset)
+{
+ return __raw_readl(port->membase + offset);
+}
+
+static inline void bcm_uart_writel(struct uart_port *port,
+ unsigned int value, unsigned int offset)
+{
+ __raw_writel(value, port->membase + offset);
+}
+
+/*
+ * serial core request to check if uart tx fifo is empty
+ */
+static unsigned int bcm_uart_tx_empty(struct uart_port *port)
+{
+ unsigned int val;
+
+ val = bcm_uart_readl(port, UART_IR_REG);
+ return (val & UART_IR_STAT(UART_IR_TXEMPTY)) ? 1 : 0;
+}
+
+/*
+ * serial core request to set RTS and DTR pin state and loopback mode
+ */
+static void bcm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+ unsigned int val;
+
+ val = bcm_uart_readl(port, UART_MCTL_REG);
+ val &= ~(UART_MCTL_DTR_MASK | UART_MCTL_RTS_MASK);
+ /* invert of written value is reflected on the pin */
+ if (!(mctrl & TIOCM_DTR))
+ val |= UART_MCTL_DTR_MASK;
+ if (!(mctrl & TIOCM_RTS))
+ val |= UART_MCTL_RTS_MASK;
+ bcm_uart_writel(port, val, UART_MCTL_REG);
+
+ val = bcm_uart_readl(port, UART_CTL_REG);
+ if (mctrl & TIOCM_LOOP)
+ val |= UART_CTL_LOOPBACK_MASK;
+ else
+ val &= ~UART_CTL_LOOPBACK_MASK;
+ bcm_uart_writel(port, val, UART_CTL_REG);
+}
+
+/*
+ * serial core request to return RI, CTS, DCD and DSR pin state
+ */
+static unsigned int bcm_uart_get_mctrl(struct uart_port *port)
+{
+ unsigned int val, mctrl;
+
+ mctrl = 0;
+ val = bcm_uart_readl(port, UART_EXTINP_REG);
+ if (val & UART_EXTINP_RI_MASK)
+ mctrl |= TIOCM_RI;
+ if (val & UART_EXTINP_CTS_MASK)
+ mctrl |= TIOCM_CTS;
+ if (val & UART_EXTINP_DCD_MASK)
+ mctrl |= TIOCM_CD;
+ if (val & UART_EXTINP_DSR_MASK)
+ mctrl |= TIOCM_DSR;
+ return mctrl;
+}
+
+/*
+ * serial core request to disable tx ASAP (used for flow control)
+ */
+static void bcm_uart_stop_tx(struct uart_port *port)
+{
+ unsigned int val;
+
+ val = bcm_uart_readl(port, UART_CTL_REG);
+ val &= ~(UART_CTL_TXEN_MASK);
+ bcm_uart_writel(port, val, UART_CTL_REG);
+
+ val = bcm_uart_readl(port, UART_IR_REG);
+ val &= ~UART_TX_INT_MASK;
+ bcm_uart_writel(port, val, UART_IR_REG);
+}
+
+/*
+ * serial core request to (re)enable tx
+ */
+static void bcm_uart_start_tx(struct uart_port *port)
+{
+ unsigned int val;
+
+ val = bcm_uart_readl(port, UART_IR_REG);
+ val |= UART_TX_INT_MASK;
+ bcm_uart_writel(port, val, UART_IR_REG);
+
+ val = bcm_uart_readl(port, UART_CTL_REG);
+ val |= UART_CTL_TXEN_MASK;
+ bcm_uart_writel(port, val, UART_CTL_REG);
+}
+
+/*
+ * serial core request to stop rx, called before port shutdown
+ */
+static void bcm_uart_stop_rx(struct uart_port *port)
+{
+ unsigned int val;
+
+ val = bcm_uart_readl(port, UART_IR_REG);
+ val &= ~UART_RX_INT_MASK;
+ bcm_uart_writel(port, val, UART_IR_REG);
+}
+
+/*
+ * serial core request to enable modem status interrupt reporting
+ */
+static void bcm_uart_enable_ms(struct uart_port *port)
+{
+ unsigned int val;
+
+ val = bcm_uart_readl(port, UART_IR_REG);
+ val |= UART_IR_MASK(UART_IR_EXTIP);
+ bcm_uart_writel(port, val, UART_IR_REG);
+}
+
+/*
+ * serial core request to start/stop emitting break char
+ */
+static void bcm_uart_break_ctl(struct uart_port *port, int ctl)
+{
+ unsigned long flags;
+ unsigned int val;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ val = bcm_uart_readl(port, UART_CTL_REG);
+ if (ctl)
+ val |= UART_CTL_XMITBRK_MASK;
+ else
+ val &= ~UART_CTL_XMITBRK_MASK;
+ bcm_uart_writel(port, val, UART_CTL_REG);
+
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/*
+ * return port type in string format
+ */
+static const char *bcm_uart_type(struct uart_port *port)
+{
+ return (port->type == PORT_BCM63XX) ? "bcm63xx_uart" : NULL;
+}
+
+/*
+ * read all chars in rx fifo and send them to core
+ */
+static void bcm_uart_do_rx(struct uart_port *port)
+{
+ struct tty_port *tty_port = &port->state->port;
+ unsigned int max_count;
+
+ /* limit number of char read in interrupt, should not be
+ * higher than fifo size anyway since we're much faster than
+ * serial port */
+ max_count = 32;
+ do {
+ unsigned int iestat, c, cstat;
+ char flag;
+
+ /* get overrun/fifo empty information from ier
+ * register */
+ iestat = bcm_uart_readl(port, UART_IR_REG);
+
+ if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) {
+ unsigned int val;
+
+ /* fifo reset is required to clear
+ * interrupt */
+ val = bcm_uart_readl(port, UART_CTL_REG);
+ val |= UART_CTL_RSTRXFIFO_MASK;
+ bcm_uart_writel(port, val, UART_CTL_REG);
+
+ port->icount.overrun++;
+ tty_insert_flip_char(tty_port, 0, TTY_OVERRUN);
+ }
+
+ if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
+ break;
+
+ cstat = c = bcm_uart_readl(port, UART_FIFO_REG);
+ port->icount.rx++;
+ flag = TTY_NORMAL;
+ c &= 0xff;
+
+ if (unlikely((cstat & UART_FIFO_ANYERR_MASK))) {
+ /* do stats first */
+ if (cstat & UART_FIFO_BRKDET_MASK) {
+ port->icount.brk++;
+ if (uart_handle_break(port))
+ continue;
+ }
+
+ if (cstat & UART_FIFO_PARERR_MASK)
+ port->icount.parity++;
+ if (cstat & UART_FIFO_FRAMEERR_MASK)
+ port->icount.frame++;
+
+ /* update flag wrt read_status_mask */
+ cstat &= port->read_status_mask;
+ if (cstat & UART_FIFO_BRKDET_MASK)
+ flag = TTY_BREAK;
+ if (cstat & UART_FIFO_FRAMEERR_MASK)
+ flag = TTY_FRAME;
+ if (cstat & UART_FIFO_PARERR_MASK)
+ flag = TTY_PARITY;
+ }
+
+ if (uart_handle_sysrq_char(port, c))
+ continue;
+
+
+ if ((cstat & port->ignore_status_mask) == 0)
+ tty_insert_flip_char(tty_port, c, flag);
+
+ } while (--max_count);
+
+ tty_flip_buffer_push(tty_port);
+}
+
+/*
+ * fill tx fifo with chars to send, stop when fifo is about to be full
+ * or when all chars have been sent.
+ */
+static void bcm_uart_do_tx(struct uart_port *port)
+{
+ struct circ_buf *xmit;
+ unsigned int val, max_count;
+
+ if (port->x_char) {
+ bcm_uart_writel(port, port->x_char, UART_FIFO_REG);
+ port->icount.tx++;
+ port->x_char = 0;
+ return;
+ }
+
+ if (uart_tx_stopped(port)) {
+ bcm_uart_stop_tx(port);
+ return;
+ }
+
+ xmit = &port->state->xmit;
+ if (uart_circ_empty(xmit))
+ goto txq_empty;
+
+ val = bcm_uart_readl(port, UART_MCTL_REG);
+ val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
+ max_count = port->fifosize - val;
+
+ while (max_count--) {
+ unsigned int c;
+
+ c = xmit->buf[xmit->tail];
+ bcm_uart_writel(port, c, UART_FIFO_REG);
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ port->icount.tx++;
+ if (uart_circ_empty(xmit))
+ break;
+ }
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(port);
+
+ if (uart_circ_empty(xmit))
+ goto txq_empty;
+ return;
+
+txq_empty:
+ /* nothing to send, disable transmit interrupt */
+ val = bcm_uart_readl(port, UART_IR_REG);
+ val &= ~UART_TX_INT_MASK;
+ bcm_uart_writel(port, val, UART_IR_REG);
+ return;
+}
+
+/*
+ * process uart interrupt
+ */
+static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
+{
+ struct uart_port *port;
+ unsigned int irqstat;
+
+ port = dev_id;
+ spin_lock(&port->lock);
+
+ irqstat = bcm_uart_readl(port, UART_IR_REG);
+ if (irqstat & UART_RX_INT_STAT)
+ bcm_uart_do_rx(port);
+
+ if (irqstat & UART_TX_INT_STAT)
+ bcm_uart_do_tx(port);
+
+ if (irqstat & UART_IR_MASK(UART_IR_EXTIP)) {
+ unsigned int estat;
+
+ estat = bcm_uart_readl(port, UART_EXTINP_REG);
+ if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_CTS))
+ uart_handle_cts_change(port,
+ estat & UART_EXTINP_CTS_MASK);
+ if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_DCD))
+ uart_handle_dcd_change(port,
+ estat & UART_EXTINP_DCD_MASK);
+ }
+
+ spin_unlock(&port->lock);
+ return IRQ_HANDLED;
+}
+
+/*
+ * enable rx & tx operation on uart
+ */
+static void bcm_uart_enable(struct uart_port *port)
+{
+ unsigned int val;
+
+ val = bcm_uart_readl(port, UART_CTL_REG);
+ val |= (UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
+ bcm_uart_writel(port, val, UART_CTL_REG);
+}
+
+/*
+ * disable rx & tx operation on uart
+ */
+static void bcm_uart_disable(struct uart_port *port)
+{
+ unsigned int val;
+
+ val = bcm_uart_readl(port, UART_CTL_REG);
+ val &= ~(UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK |
+ UART_CTL_RXEN_MASK);
+ bcm_uart_writel(port, val, UART_CTL_REG);
+}
+
+/*
+ * clear all unread data in rx fifo and unsent data in tx fifo
+ */
+static void bcm_uart_flush(struct uart_port *port)
+{
+ unsigned int val;
+
+ /* empty rx and tx fifo */
+ val = bcm_uart_readl(port, UART_CTL_REG);
+ val |= UART_CTL_RSTRXFIFO_MASK | UART_CTL_RSTTXFIFO_MASK;
+ bcm_uart_writel(port, val, UART_CTL_REG);
+
+ /* read any pending char to make sure all irq status are
+ * cleared */
+ (void)bcm_uart_readl(port, UART_FIFO_REG);
+}
+
+/*
+ * serial core request to initialize uart and start rx operation
+ */
+static int bcm_uart_startup(struct uart_port *port)
+{
+ unsigned int val;
+ int ret;
+
+ /* mask all irq and flush port */
+ bcm_uart_disable(port);
+ bcm_uart_writel(port, 0, UART_IR_REG);
+ bcm_uart_flush(port);
+
+ /* clear any pending external input interrupt */
+ (void)bcm_uart_readl(port, UART_EXTINP_REG);
+
+ /* set rx/tx fifo thresh to fifo half size */
+ val = bcm_uart_readl(port, UART_MCTL_REG);
+ val &= ~(UART_MCTL_RXFIFOTHRESH_MASK | UART_MCTL_TXFIFOTHRESH_MASK);
+ val |= (port->fifosize / 2) << UART_MCTL_RXFIFOTHRESH_SHIFT;
+ val |= (port->fifosize / 2) << UART_MCTL_TXFIFOTHRESH_SHIFT;
+ bcm_uart_writel(port, val, UART_MCTL_REG);
+
+ /* set rx fifo timeout to 1 char time */
+ val = bcm_uart_readl(port, UART_CTL_REG);
+ val &= ~UART_CTL_RXTMOUTCNT_MASK;
+ val |= 1 << UART_CTL_RXTMOUTCNT_SHIFT;
+ bcm_uart_writel(port, val, UART_CTL_REG);
+
+ /* report any edge on dcd and cts */
+ val = UART_EXTINP_INT_MASK;
+ val |= UART_EXTINP_DCD_NOSENSE_MASK;
+ val |= UART_EXTINP_CTS_NOSENSE_MASK;
+ bcm_uart_writel(port, val, UART_EXTINP_REG);
+
+ /* register irq and enable rx interrupts */
+ ret = request_irq(port->irq, bcm_uart_interrupt, 0,
+ dev_name(port->dev), port);
+ if (ret)
+ return ret;
+ bcm_uart_writel(port, UART_RX_INT_MASK, UART_IR_REG);
+ bcm_uart_enable(port);
+ return 0;
+}
+
+/*
+ * serial core request to flush & disable uart
+ */
+static void bcm_uart_shutdown(struct uart_port *port)
+{
+ unsigned long flags;
+
+ spin_lock_irqsave(&port->lock, flags);
+ bcm_uart_writel(port, 0, UART_IR_REG);
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ bcm_uart_disable(port);
+ bcm_uart_flush(port);
+ free_irq(port->irq, port);
+}
+
+/*
+ * serial core request to change current uart setting
+ */
+static void bcm_uart_set_termios(struct uart_port *port, struct ktermios *new,
+ const struct ktermios *old)
+{
+ unsigned int ctl, baud, quot, ier;
+ unsigned long flags;
+ int tries;
+
+ spin_lock_irqsave(&port->lock, flags);
+
+ /* Drain the hot tub fully before we power it off for the winter. */
+ for (tries = 3; !bcm_uart_tx_empty(port) && tries; tries--)
+ mdelay(10);
+
+ /* disable uart while changing speed */
+ bcm_uart_disable(port);
+ bcm_uart_flush(port);
+
+ /* update Control register */
+ ctl = bcm_uart_readl(port, UART_CTL_REG);
+ ctl &= ~UART_CTL_BITSPERSYM_MASK;
+
+ switch (new->c_cflag & CSIZE) {
+ case CS5:
+ ctl |= (0 << UART_CTL_BITSPERSYM_SHIFT);
+ break;
+ case CS6:
+ ctl |= (1 << UART_CTL_BITSPERSYM_SHIFT);
+ break;
+ case CS7:
+ ctl |= (2 << UART_CTL_BITSPERSYM_SHIFT);
+ break;
+ default:
+ ctl |= (3 << UART_CTL_BITSPERSYM_SHIFT);
+ break;
+ }
+
+ ctl &= ~UART_CTL_STOPBITS_MASK;
+ if (new->c_cflag & CSTOPB)
+ ctl |= UART_CTL_STOPBITS_2;
+ else
+ ctl |= UART_CTL_STOPBITS_1;
+
+ ctl &= ~(UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
+ if (new->c_cflag & PARENB)
+ ctl |= (UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
+ ctl &= ~(UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
+ if (new->c_cflag & PARODD)
+ ctl |= (UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
+ bcm_uart_writel(port, ctl, UART_CTL_REG);
+
+ /* update Baudword register */
+ baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
+ quot = uart_get_divisor(port, baud) - 1;
+ bcm_uart_writel(port, quot, UART_BAUD_REG);
+
+ /* update Interrupt register */
+ ier = bcm_uart_readl(port, UART_IR_REG);
+
+ ier &= ~UART_IR_MASK(UART_IR_EXTIP);
+ if (UART_ENABLE_MS(port, new->c_cflag))
+ ier |= UART_IR_MASK(UART_IR_EXTIP);
+
+ bcm_uart_writel(port, ier, UART_IR_REG);
+
+ /* update read/ignore mask */
+ port->read_status_mask = UART_FIFO_VALID_MASK;
+ if (new->c_iflag & INPCK) {
+ port->read_status_mask |= UART_FIFO_FRAMEERR_MASK;
+ port->read_status_mask |= UART_FIFO_PARERR_MASK;
+ }
+ if (new->c_iflag & (IGNBRK | BRKINT))
+ port->read_status_mask |= UART_FIFO_BRKDET_MASK;
+
+ port->ignore_status_mask = 0;
+ if (new->c_iflag & IGNPAR)
+ port->ignore_status_mask |= UART_FIFO_PARERR_MASK;
+ if (new->c_iflag & IGNBRK)
+ port->ignore_status_mask |= UART_FIFO_BRKDET_MASK;
+ if (!(new->c_cflag & CREAD))
+ port->ignore_status_mask |= UART_FIFO_VALID_MASK;
+
+ uart_update_timeout(port, new->c_cflag, baud);
+ bcm_uart_enable(port);
+ spin_unlock_irqrestore(&port->lock, flags);
+}
+
+/*
+ * serial core request to claim uart iomem
+ */
+static int bcm_uart_request_port(struct uart_port *port)
+{
+ /* UARTs always present */
+ return 0;
+}
+
+/*
+ * serial core request to release uart iomem
+ */
+static void bcm_uart_release_port(struct uart_port *port)
+{
+ /* Nothing to release ... */
+}
+
+/*
+ * serial core request to do any port required autoconfiguration
+ */
+static void bcm_uart_config_port(struct uart_port *port, int flags)
+{
+ if (flags & UART_CONFIG_TYPE) {
+ if (bcm_uart_request_port(port))
+ return;
+ port->type = PORT_BCM63XX;
+ }
+}
+
+/*
+ * serial core request to check that port information in serinfo are
+ * suitable
+ */
+static int bcm_uart_verify_port(struct uart_port *port,
+ struct serial_struct *serinfo)
+{
+ if (port->type != PORT_BCM63XX)
+ return -EINVAL;
+ if (port->irq != serinfo->irq)
+ return -EINVAL;
+ if (port->iotype != serinfo->io_type)
+ return -EINVAL;
+ if (port->mapbase != (unsigned long)serinfo->iomem_base)
+ return -EINVAL;
+ return 0;
+}
+
+/* serial core callbacks */
+static const struct uart_ops bcm_uart_ops = {
+ .tx_empty = bcm_uart_tx_empty,
+ .get_mctrl = bcm_uart_get_mctrl,
+ .set_mctrl = bcm_uart_set_mctrl,
+ .start_tx = bcm_uart_start_tx,
+ .stop_tx = bcm_uart_stop_tx,
+ .stop_rx = bcm_uart_stop_rx,
+ .enable_ms = bcm_uart_enable_ms,
+ .break_ctl = bcm_uart_break_ctl,
+ .startup = bcm_uart_startup,
+ .shutdown = bcm_uart_shutdown,
+ .set_termios = bcm_uart_set_termios,
+ .type = bcm_uart_type,
+ .release_port = bcm_uart_release_port,
+ .request_port = bcm_uart_request_port,
+ .config_port = bcm_uart_config_port,
+ .verify_port = bcm_uart_verify_port,
+};
+
+
+
+#ifdef CONFIG_SERIAL_BCM63XX_CONSOLE
+static void wait_for_xmitr(struct uart_port *port)
+{
+ unsigned int tmout;
+
+ /* Wait up to 10ms for the character(s) to be sent. */
+ tmout = 10000;
+ while (--tmout) {
+ unsigned int val;
+
+ val = bcm_uart_readl(port, UART_IR_REG);
+ if (val & UART_IR_STAT(UART_IR_TXEMPTY))
+ break;
+ udelay(1);
+ }
+
+ /* Wait up to 1s for flow control if necessary */
+ if (port->flags & UPF_CONS_FLOW) {
+ tmout = 1000000;
+ while (--tmout) {
+ unsigned int val;
+
+ val = bcm_uart_readl(port, UART_EXTINP_REG);
+ if (val & UART_EXTINP_CTS_MASK)
+ break;
+ udelay(1);
+ }
+ }
+}
+
+/*
+ * output given char
+ */
+static void bcm_console_putchar(struct uart_port *port, unsigned char ch)
+{
+ wait_for_xmitr(port);
+ bcm_uart_writel(port, ch, UART_FIFO_REG);
+}
+
+/*
+ * console core request to output given string
+ */
+static void bcm_console_write(struct console *co, const char *s,
+ unsigned int count)
+{
+ struct uart_port *port;
+ unsigned long flags;
+ int locked;
+
+ port = &ports[co->index];
+
+ local_irq_save(flags);
+ if (port->sysrq) {
+ /* bcm_uart_interrupt() already took the lock */
+ locked = 0;
+ } else if (oops_in_progress) {
+ locked = spin_trylock(&port->lock);
+ } else {
+ spin_lock(&port->lock);
+ locked = 1;
+ }
+
+ /* call helper to deal with \r\n */
+ uart_console_write(port, s, count, bcm_console_putchar);
+
+ /* and wait for char to be transmitted */
+ wait_for_xmitr(port);
+
+ if (locked)
+ spin_unlock(&port->lock);
+ local_irq_restore(flags);
+}
+
+/*
+ * console core request to setup given console, find matching uart
+ * port and setup it.
+ */
+static int bcm_console_setup(struct console *co, char *options)
+{
+ struct uart_port *port;
+ int baud = 9600;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+
+ if (co->index < 0 || co->index >= BCM63XX_NR_UARTS)
+ return -EINVAL;
+ port = &ports[co->index];
+ if (!port->membase)
+ return -ENODEV;
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+
+ return uart_set_options(port, co, baud, parity, bits, flow);
+}
+
+static struct uart_driver bcm_uart_driver;
+
+static struct console bcm63xx_console = {
+ .name = "ttyS",
+ .write = bcm_console_write,
+ .device = uart_console_device,
+ .setup = bcm_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &bcm_uart_driver,
+};
+
+static int __init bcm63xx_console_init(void)
+{
+ register_console(&bcm63xx_console);
+ return 0;
+}
+
+console_initcall(bcm63xx_console_init);
+
+static void bcm_early_write(struct console *con, const char *s, unsigned n)
+{
+ struct earlycon_device *dev = con->data;
+
+ uart_console_write(&dev->port, s, n, bcm_console_putchar);
+ wait_for_xmitr(&dev->port);
+}
+
+static int __init bcm_early_console_setup(struct earlycon_device *device,
+ const char *opt)
+{
+ if (!device->port.membase)
+ return -ENODEV;
+
+ device->con->write = bcm_early_write;
+ return 0;
+}
+
+OF_EARLYCON_DECLARE(bcm63xx_uart, "brcm,bcm6345-uart", bcm_early_console_setup);
+
+#define BCM63XX_CONSOLE (&bcm63xx_console)
+#else
+#define BCM63XX_CONSOLE NULL
+#endif /* CONFIG_SERIAL_BCM63XX_CONSOLE */
+
+static struct uart_driver bcm_uart_driver = {
+ .owner = THIS_MODULE,
+ .driver_name = "bcm63xx_uart",
+ .dev_name = "ttyS",
+ .major = TTY_MAJOR,
+ .minor = 64,
+ .nr = BCM63XX_NR_UARTS,
+ .cons = BCM63XX_CONSOLE,
+};
+
+/*
+ * platform driver probe/remove callback
+ */
+static int bcm_uart_probe(struct platform_device *pdev)
+{
+ struct resource *res_mem;
+ struct uart_port *port;
+ struct clk *clk;
+ int ret;
+
+ if (pdev->dev.of_node) {
+ pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
+
+ if (pdev->id < 0)
+ pdev->id = of_alias_get_id(pdev->dev.of_node, "uart");
+ }
+
+ if (pdev->id < 0 || pdev->id >= BCM63XX_NR_UARTS)
+ return -EINVAL;
+
+ port = &ports[pdev->id];
+ if (port->membase)
+ return -EBUSY;
+ memset(port, 0, sizeof(*port));
+
+ res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res_mem)
+ return -ENODEV;
+
+ port->mapbase = res_mem->start;
+ port->membase = devm_ioremap_resource(&pdev->dev, res_mem);
+ if (IS_ERR(port->membase))
+ return PTR_ERR(port->membase);
+
+ ret = platform_get_irq(pdev, 0);
+ if (ret < 0)
+ return ret;
+ port->irq = ret;
+
+ clk = clk_get(&pdev->dev, "refclk");
+ if (IS_ERR(clk) && pdev->dev.of_node)
+ clk = of_clk_get(pdev->dev.of_node, 0);
+
+ if (IS_ERR(clk))
+ return -ENODEV;
+
+ port->iotype = UPIO_MEM;
+ port->ops = &bcm_uart_ops;
+ port->flags = UPF_BOOT_AUTOCONF;
+ port->dev = &pdev->dev;
+ port->fifosize = 16;
+ port->uartclk = clk_get_rate(clk) / 2;
+ port->line = pdev->id;
+ port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_BCM63XX_CONSOLE);
+ clk_put(clk);
+
+ ret = uart_add_one_port(&bcm_uart_driver, port);
+ if (ret) {
+ ports[pdev->id].membase = NULL;
+ return ret;
+ }
+ platform_set_drvdata(pdev, port);
+ return 0;
+}
+
+static int bcm_uart_remove(struct platform_device *pdev)
+{
+ struct uart_port *port;
+
+ port = platform_get_drvdata(pdev);
+ uart_remove_one_port(&bcm_uart_driver, port);
+ /* mark port as free */
+ ports[pdev->id].membase = NULL;
+ return 0;
+}
+
+static const struct of_device_id bcm63xx_of_match[] = {
+ { .compatible = "brcm,bcm6345-uart" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, bcm63xx_of_match);
+
+/*
+ * platform driver stuff
+ */
+static struct platform_driver bcm_uart_platform_driver = {
+ .probe = bcm_uart_probe,
+ .remove = bcm_uart_remove,
+ .driver = {
+ .name = "bcm63xx_uart",
+ .of_match_table = bcm63xx_of_match,
+ },
+};
+
+static int __init bcm_uart_init(void)
+{
+ int ret;
+
+ ret = uart_register_driver(&bcm_uart_driver);
+ if (ret)
+ return ret;
+
+ ret = platform_driver_register(&bcm_uart_platform_driver);
+ if (ret)
+ uart_unregister_driver(&bcm_uart_driver);
+
+ return ret;
+}
+
+static void __exit bcm_uart_exit(void)
+{
+ platform_driver_unregister(&bcm_uart_platform_driver);
+ uart_unregister_driver(&bcm_uart_driver);
+}
+
+module_init(bcm_uart_init);
+module_exit(bcm_uart_exit);
+
+MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
+MODULE_DESCRIPTION("Broadcom 63xx integrated uart driver");
+MODULE_LICENSE("GPL");