linux/drivers/tty/serial/rda-uart.c
Johan Hovold 2225ee132c serial: rda: drop low-latency workaround
The rda driver has always carried an unnecessary workaround for the
infamous low_latency behaviour of tty_flip_buffer_push(), which had
been removed years before the driver was added by commit c10b13325c
("tty: serial: Add RDA8810PL UART driver").

Specifically, since commit a9c3f68f3c ("tty: Fix low_latency BUG"),
tty_flip_buffer_push() always schedules a work item to push data to the
line discipline and there's no need to keep any low_latency hacks around.

Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210421095509.3024-19-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-04-22 12:09:26 +02:00

828 lines
20 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* RDA8810PL serial device driver
*
* Copyright RDA Microelectronics Company Limited
* Copyright (c) 2017 Andreas Färber
* Copyright (c) 2018 Manivannan Sadhasivam
*/
#include <linux/clk.h>
#include <linux/console.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#define RDA_UART_PORT_NUM 3
#define RDA_UART_DEV_NAME "ttyRDA"
#define RDA_UART_CTRL 0x00
#define RDA_UART_STATUS 0x04
#define RDA_UART_RXTX_BUFFER 0x08
#define RDA_UART_IRQ_MASK 0x0c
#define RDA_UART_IRQ_CAUSE 0x10
#define RDA_UART_IRQ_TRIGGERS 0x14
#define RDA_UART_CMD_SET 0x18
#define RDA_UART_CMD_CLR 0x1c
/* UART_CTRL Bits */
#define RDA_UART_ENABLE BIT(0)
#define RDA_UART_DBITS_8 BIT(1)
#define RDA_UART_TX_SBITS_2 BIT(2)
#define RDA_UART_PARITY_EN BIT(3)
#define RDA_UART_PARITY(x) (((x) & 0x3) << 4)
#define RDA_UART_PARITY_ODD RDA_UART_PARITY(0)
#define RDA_UART_PARITY_EVEN RDA_UART_PARITY(1)
#define RDA_UART_PARITY_SPACE RDA_UART_PARITY(2)
#define RDA_UART_PARITY_MARK RDA_UART_PARITY(3)
#define RDA_UART_DIV_MODE BIT(20)
#define RDA_UART_IRDA_EN BIT(21)
#define RDA_UART_DMA_EN BIT(22)
#define RDA_UART_FLOW_CNT_EN BIT(23)
#define RDA_UART_LOOP_BACK_EN BIT(24)
#define RDA_UART_RX_LOCK_ERR BIT(25)
#define RDA_UART_RX_BREAK_LEN(x) (((x) & 0xf) << 28)
/* UART_STATUS Bits */
#define RDA_UART_RX_FIFO(x) (((x) & 0x7f) << 0)
#define RDA_UART_RX_FIFO_MASK (0x7f << 0)
#define RDA_UART_TX_FIFO(x) (((x) & 0x1f) << 8)
#define RDA_UART_TX_FIFO_MASK (0x1f << 8)
#define RDA_UART_TX_ACTIVE BIT(14)
#define RDA_UART_RX_ACTIVE BIT(15)
#define RDA_UART_RX_OVERFLOW_ERR BIT(16)
#define RDA_UART_TX_OVERFLOW_ERR BIT(17)
#define RDA_UART_RX_PARITY_ERR BIT(18)
#define RDA_UART_RX_FRAMING_ERR BIT(19)
#define RDA_UART_RX_BREAK_INT BIT(20)
#define RDA_UART_DCTS BIT(24)
#define RDA_UART_CTS BIT(25)
#define RDA_UART_DTR BIT(28)
#define RDA_UART_CLK_ENABLED BIT(31)
/* UART_RXTX_BUFFER Bits */
#define RDA_UART_RX_DATA(x) (((x) & 0xff) << 0)
#define RDA_UART_TX_DATA(x) (((x) & 0xff) << 0)
/* UART_IRQ_MASK Bits */
#define RDA_UART_TX_MODEM_STATUS BIT(0)
#define RDA_UART_RX_DATA_AVAILABLE BIT(1)
#define RDA_UART_TX_DATA_NEEDED BIT(2)
#define RDA_UART_RX_TIMEOUT BIT(3)
#define RDA_UART_RX_LINE_ERR BIT(4)
#define RDA_UART_TX_DMA_DONE BIT(5)
#define RDA_UART_RX_DMA_DONE BIT(6)
#define RDA_UART_RX_DMA_TIMEOUT BIT(7)
#define RDA_UART_DTR_RISE BIT(8)
#define RDA_UART_DTR_FALL BIT(9)
/* UART_IRQ_CAUSE Bits */
#define RDA_UART_TX_MODEM_STATUS_U BIT(16)
#define RDA_UART_RX_DATA_AVAILABLE_U BIT(17)
#define RDA_UART_TX_DATA_NEEDED_U BIT(18)
#define RDA_UART_RX_TIMEOUT_U BIT(19)
#define RDA_UART_RX_LINE_ERR_U BIT(20)
#define RDA_UART_TX_DMA_DONE_U BIT(21)
#define RDA_UART_RX_DMA_DONE_U BIT(22)
#define RDA_UART_RX_DMA_TIMEOUT_U BIT(23)
#define RDA_UART_DTR_RISE_U BIT(24)
#define RDA_UART_DTR_FALL_U BIT(25)
/* UART_TRIGGERS Bits */
#define RDA_UART_RX_TRIGGER(x) (((x) & 0x1f) << 0)
#define RDA_UART_TX_TRIGGER(x) (((x) & 0xf) << 8)
#define RDA_UART_AFC_LEVEL(x) (((x) & 0x1f) << 16)
/* UART_CMD_SET Bits */
#define RDA_UART_RI BIT(0)
#define RDA_UART_DCD BIT(1)
#define RDA_UART_DSR BIT(2)
#define RDA_UART_TX_BREAK_CONTROL BIT(3)
#define RDA_UART_TX_FINISH_N_WAIT BIT(4)
#define RDA_UART_RTS BIT(5)
#define RDA_UART_RX_FIFO_RESET BIT(6)
#define RDA_UART_TX_FIFO_RESET BIT(7)
#define RDA_UART_TX_FIFO_SIZE 16
static struct uart_driver rda_uart_driver;
struct rda_uart_port {
struct uart_port port;
struct clk *clk;
};
#define to_rda_uart_port(port) container_of(port, struct rda_uart_port, port)
static struct rda_uart_port *rda_uart_ports[RDA_UART_PORT_NUM];
static inline void rda_uart_write(struct uart_port *port, u32 val,
unsigned int off)
{
writel(val, port->membase + off);
}
static inline u32 rda_uart_read(struct uart_port *port, unsigned int off)
{
return readl(port->membase + off);
}
static unsigned int rda_uart_tx_empty(struct uart_port *port)
{
unsigned long flags;
unsigned int ret;
u32 val;
spin_lock_irqsave(&port->lock, flags);
val = rda_uart_read(port, RDA_UART_STATUS);
ret = (val & RDA_UART_TX_FIFO_MASK) ? TIOCSER_TEMT : 0;
spin_unlock_irqrestore(&port->lock, flags);
return ret;
}
static unsigned int rda_uart_get_mctrl(struct uart_port *port)
{
unsigned int mctrl = 0;
u32 cmd_set, status;
cmd_set = rda_uart_read(port, RDA_UART_CMD_SET);
status = rda_uart_read(port, RDA_UART_STATUS);
if (cmd_set & RDA_UART_RTS)
mctrl |= TIOCM_RTS;
if (!(status & RDA_UART_CTS))
mctrl |= TIOCM_CTS;
return mctrl;
}
static void rda_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
u32 val;
if (mctrl & TIOCM_RTS) {
val = rda_uart_read(port, RDA_UART_CMD_SET);
rda_uart_write(port, (val | RDA_UART_RTS), RDA_UART_CMD_SET);
} else {
/* Clear RTS to stop to receive. */
val = rda_uart_read(port, RDA_UART_CMD_CLR);
rda_uart_write(port, (val | RDA_UART_RTS), RDA_UART_CMD_CLR);
}
val = rda_uart_read(port, RDA_UART_CTRL);
if (mctrl & TIOCM_LOOP)
val |= RDA_UART_LOOP_BACK_EN;
else
val &= ~RDA_UART_LOOP_BACK_EN;
rda_uart_write(port, val, RDA_UART_CTRL);
}
static void rda_uart_stop_tx(struct uart_port *port)
{
u32 val;
val = rda_uart_read(port, RDA_UART_IRQ_MASK);
val &= ~RDA_UART_TX_DATA_NEEDED;
rda_uart_write(port, val, RDA_UART_IRQ_MASK);
val = rda_uart_read(port, RDA_UART_CMD_SET);
val |= RDA_UART_TX_FIFO_RESET;
rda_uart_write(port, val, RDA_UART_CMD_SET);
}
static void rda_uart_stop_rx(struct uart_port *port)
{
u32 val;
val = rda_uart_read(port, RDA_UART_IRQ_MASK);
val &= ~(RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT);
rda_uart_write(port, val, RDA_UART_IRQ_MASK);
/* Read Rx buffer before reset to avoid Rx timeout interrupt */
val = rda_uart_read(port, RDA_UART_RXTX_BUFFER);
val = rda_uart_read(port, RDA_UART_CMD_SET);
val |= RDA_UART_RX_FIFO_RESET;
rda_uart_write(port, val, RDA_UART_CMD_SET);
}
static void rda_uart_start_tx(struct uart_port *port)
{
u32 val;
if (uart_tx_stopped(port)) {
rda_uart_stop_tx(port);
return;
}
val = rda_uart_read(port, RDA_UART_IRQ_MASK);
val |= RDA_UART_TX_DATA_NEEDED;
rda_uart_write(port, val, RDA_UART_IRQ_MASK);
}
static void rda_uart_change_baudrate(struct rda_uart_port *rda_port,
unsigned long baud)
{
clk_set_rate(rda_port->clk, baud * 8);
}
static void rda_uart_set_termios(struct uart_port *port,
struct ktermios *termios,
struct ktermios *old)
{
struct rda_uart_port *rda_port = to_rda_uart_port(port);
unsigned long flags;
unsigned int ctrl, cmd_set, cmd_clr, triggers;
unsigned int baud;
u32 irq_mask;
spin_lock_irqsave(&port->lock, flags);
baud = uart_get_baud_rate(port, termios, old, 9600, port->uartclk / 4);
rda_uart_change_baudrate(rda_port, baud);
ctrl = rda_uart_read(port, RDA_UART_CTRL);
cmd_set = rda_uart_read(port, RDA_UART_CMD_SET);
cmd_clr = rda_uart_read(port, RDA_UART_CMD_CLR);
switch (termios->c_cflag & CSIZE) {
case CS5:
case CS6:
dev_warn(port->dev, "bit size not supported, using 7 bits\n");
fallthrough;
case CS7:
ctrl &= ~RDA_UART_DBITS_8;
break;
default:
ctrl |= RDA_UART_DBITS_8;
break;
}
/* stop bits */
if (termios->c_cflag & CSTOPB)
ctrl |= RDA_UART_TX_SBITS_2;
else
ctrl &= ~RDA_UART_TX_SBITS_2;
/* parity check */
if (termios->c_cflag & PARENB) {
ctrl |= RDA_UART_PARITY_EN;
/* Mark or Space parity */
if (termios->c_cflag & CMSPAR) {
if (termios->c_cflag & PARODD)
ctrl |= RDA_UART_PARITY_MARK;
else
ctrl |= RDA_UART_PARITY_SPACE;
} else if (termios->c_cflag & PARODD) {
ctrl |= RDA_UART_PARITY_ODD;
} else {
ctrl |= RDA_UART_PARITY_EVEN;
}
} else {
ctrl &= ~RDA_UART_PARITY_EN;
}
/* Hardware handshake (RTS/CTS) */
if (termios->c_cflag & CRTSCTS) {
ctrl |= RDA_UART_FLOW_CNT_EN;
cmd_set |= RDA_UART_RTS;
} else {
ctrl &= ~RDA_UART_FLOW_CNT_EN;
cmd_clr |= RDA_UART_RTS;
}
ctrl |= RDA_UART_ENABLE;
ctrl &= ~RDA_UART_DMA_EN;
triggers = (RDA_UART_AFC_LEVEL(20) | RDA_UART_RX_TRIGGER(16));
irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
rda_uart_write(port, triggers, RDA_UART_IRQ_TRIGGERS);
rda_uart_write(port, ctrl, RDA_UART_CTRL);
rda_uart_write(port, cmd_set, RDA_UART_CMD_SET);
rda_uart_write(port, cmd_clr, RDA_UART_CMD_CLR);
rda_uart_write(port, irq_mask, RDA_UART_IRQ_MASK);
/* Don't rewrite B0 */
if (tty_termios_baud_rate(termios))
tty_termios_encode_baud_rate(termios, baud, baud);
/* update the per-port timeout */
uart_update_timeout(port, termios->c_cflag, baud);
spin_unlock_irqrestore(&port->lock, flags);
}
static void rda_uart_send_chars(struct uart_port *port)
{
struct circ_buf *xmit = &port->state->xmit;
unsigned int ch;
u32 val;
if (uart_tx_stopped(port))
return;
if (port->x_char) {
while (!(rda_uart_read(port, RDA_UART_STATUS) &
RDA_UART_TX_FIFO_MASK))
cpu_relax();
rda_uart_write(port, port->x_char, RDA_UART_RXTX_BUFFER);
port->icount.tx++;
port->x_char = 0;
}
while (rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK) {
if (uart_circ_empty(xmit))
break;
ch = xmit->buf[xmit->tail];
rda_uart_write(port, ch, RDA_UART_RXTX_BUFFER);
xmit->tail = (xmit->tail + 1) & (SERIAL_XMIT_SIZE - 1);
port->icount.tx++;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
if (!uart_circ_empty(xmit)) {
/* Re-enable Tx FIFO interrupt */
val = rda_uart_read(port, RDA_UART_IRQ_MASK);
val |= RDA_UART_TX_DATA_NEEDED;
rda_uart_write(port, val, RDA_UART_IRQ_MASK);
}
}
static void rda_uart_receive_chars(struct uart_port *port)
{
u32 status, val;
status = rda_uart_read(port, RDA_UART_STATUS);
while ((status & RDA_UART_RX_FIFO_MASK)) {
char flag = TTY_NORMAL;
if (status & RDA_UART_RX_PARITY_ERR) {
port->icount.parity++;
flag = TTY_PARITY;
}
if (status & RDA_UART_RX_FRAMING_ERR) {
port->icount.frame++;
flag = TTY_FRAME;
}
if (status & RDA_UART_RX_OVERFLOW_ERR) {
port->icount.overrun++;
flag = TTY_OVERRUN;
}
val = rda_uart_read(port, RDA_UART_RXTX_BUFFER);
val &= 0xff;
port->icount.rx++;
tty_insert_flip_char(&port->state->port, val, flag);
status = rda_uart_read(port, RDA_UART_STATUS);
}
tty_flip_buffer_push(&port->state->port);
}
static irqreturn_t rda_interrupt(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
unsigned long flags;
u32 val, irq_mask;
spin_lock_irqsave(&port->lock, flags);
/* Clear IRQ cause */
val = rda_uart_read(port, RDA_UART_IRQ_CAUSE);
rda_uart_write(port, val, RDA_UART_IRQ_CAUSE);
if (val & (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT))
rda_uart_receive_chars(port);
if (val & (RDA_UART_TX_DATA_NEEDED)) {
irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
irq_mask &= ~RDA_UART_TX_DATA_NEEDED;
rda_uart_write(port, irq_mask, RDA_UART_IRQ_MASK);
rda_uart_send_chars(port);
}
spin_unlock_irqrestore(&port->lock, flags);
return IRQ_HANDLED;
}
static int rda_uart_startup(struct uart_port *port)
{
unsigned long flags;
int ret;
u32 val;
spin_lock_irqsave(&port->lock, flags);
rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
spin_unlock_irqrestore(&port->lock, flags);
ret = request_irq(port->irq, rda_interrupt, IRQF_NO_SUSPEND,
"rda-uart", port);
if (ret)
return ret;
spin_lock_irqsave(&port->lock, flags);
val = rda_uart_read(port, RDA_UART_CTRL);
val |= RDA_UART_ENABLE;
rda_uart_write(port, val, RDA_UART_CTRL);
/* enable rx interrupt */
val = rda_uart_read(port, RDA_UART_IRQ_MASK);
val |= (RDA_UART_RX_DATA_AVAILABLE | RDA_UART_RX_TIMEOUT);
rda_uart_write(port, val, RDA_UART_IRQ_MASK);
spin_unlock_irqrestore(&port->lock, flags);
return 0;
}
static void rda_uart_shutdown(struct uart_port *port)
{
unsigned long flags;
u32 val;
spin_lock_irqsave(&port->lock, flags);
rda_uart_stop_tx(port);
rda_uart_stop_rx(port);
val = rda_uart_read(port, RDA_UART_CTRL);
val &= ~RDA_UART_ENABLE;
rda_uart_write(port, val, RDA_UART_CTRL);
spin_unlock_irqrestore(&port->lock, flags);
}
static const char *rda_uart_type(struct uart_port *port)
{
return (port->type == PORT_RDA) ? "rda-uart" : NULL;
}
static int rda_uart_request_port(struct uart_port *port)
{
struct platform_device *pdev = to_platform_device(port->dev);
struct resource *res;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENXIO;
if (!devm_request_mem_region(port->dev, port->mapbase,
resource_size(res), dev_name(port->dev)))
return -EBUSY;
if (port->flags & UPF_IOREMAP) {
port->membase = devm_ioremap(port->dev, port->mapbase,
resource_size(res));
if (!port->membase)
return -EBUSY;
}
return 0;
}
static void rda_uart_config_port(struct uart_port *port, int flags)
{
unsigned long irq_flags;
if (flags & UART_CONFIG_TYPE) {
port->type = PORT_RDA;
rda_uart_request_port(port);
}
spin_lock_irqsave(&port->lock, irq_flags);
/* Clear mask, so no surprise interrupts. */
rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
/* Clear status register */
rda_uart_write(port, 0, RDA_UART_STATUS);
spin_unlock_irqrestore(&port->lock, irq_flags);
}
static void rda_uart_release_port(struct uart_port *port)
{
struct platform_device *pdev = to_platform_device(port->dev);
struct resource *res;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return;
if (port->flags & UPF_IOREMAP) {
devm_release_mem_region(port->dev, port->mapbase,
resource_size(res));
devm_iounmap(port->dev, port->membase);
port->membase = NULL;
}
}
static int rda_uart_verify_port(struct uart_port *port,
struct serial_struct *ser)
{
if (port->type != PORT_RDA)
return -EINVAL;
if (port->irq != ser->irq)
return -EINVAL;
return 0;
}
static const struct uart_ops rda_uart_ops = {
.tx_empty = rda_uart_tx_empty,
.get_mctrl = rda_uart_get_mctrl,
.set_mctrl = rda_uart_set_mctrl,
.start_tx = rda_uart_start_tx,
.stop_tx = rda_uart_stop_tx,
.stop_rx = rda_uart_stop_rx,
.startup = rda_uart_startup,
.shutdown = rda_uart_shutdown,
.set_termios = rda_uart_set_termios,
.type = rda_uart_type,
.request_port = rda_uart_request_port,
.release_port = rda_uart_release_port,
.config_port = rda_uart_config_port,
.verify_port = rda_uart_verify_port,
};
#ifdef CONFIG_SERIAL_RDA_CONSOLE
static void rda_console_putchar(struct uart_port *port, int ch)
{
if (!port->membase)
return;
while (!(rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK))
cpu_relax();
rda_uart_write(port, ch, RDA_UART_RXTX_BUFFER);
}
static void rda_uart_port_write(struct uart_port *port, const char *s,
u_int count)
{
u32 old_irq_mask;
unsigned long flags;
int locked;
local_irq_save(flags);
if (port->sysrq) {
locked = 0;
} else if (oops_in_progress) {
locked = spin_trylock(&port->lock);
} else {
spin_lock(&port->lock);
locked = 1;
}
old_irq_mask = rda_uart_read(port, RDA_UART_IRQ_MASK);
rda_uart_write(port, 0, RDA_UART_IRQ_MASK);
uart_console_write(port, s, count, rda_console_putchar);
/* wait until all contents have been sent out */
while (!(rda_uart_read(port, RDA_UART_STATUS) & RDA_UART_TX_FIFO_MASK))
cpu_relax();
rda_uart_write(port, old_irq_mask, RDA_UART_IRQ_MASK);
if (locked)
spin_unlock(&port->lock);
local_irq_restore(flags);
}
static void rda_uart_console_write(struct console *co, const char *s,
u_int count)
{
struct rda_uart_port *rda_port;
rda_port = rda_uart_ports[co->index];
if (!rda_port)
return;
rda_uart_port_write(&rda_port->port, s, count);
}
static int rda_uart_console_setup(struct console *co, char *options)
{
struct rda_uart_port *rda_port;
int baud = 921600;
int bits = 8;
int parity = 'n';
int flow = 'n';
if (co->index < 0 || co->index >= RDA_UART_PORT_NUM)
return -EINVAL;
rda_port = rda_uart_ports[co->index];
if (!rda_port || !rda_port->port.membase)
return -ENODEV;
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
return uart_set_options(&rda_port->port, co, baud, parity, bits, flow);
}
static struct console rda_uart_console = {
.name = RDA_UART_DEV_NAME,
.write = rda_uart_console_write,
.device = uart_console_device,
.setup = rda_uart_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &rda_uart_driver,
};
static int __init rda_uart_console_init(void)
{
register_console(&rda_uart_console);
return 0;
}
console_initcall(rda_uart_console_init);
static void rda_uart_early_console_write(struct console *co,
const char *s,
u_int count)
{
struct earlycon_device *dev = co->data;
rda_uart_port_write(&dev->port, s, count);
}
static int __init
rda_uart_early_console_setup(struct earlycon_device *device, const char *opt)
{
if (!device->port.membase)
return -ENODEV;
device->con->write = rda_uart_early_console_write;
return 0;
}
OF_EARLYCON_DECLARE(rda, "rda,8810pl-uart",
rda_uart_early_console_setup);
#define RDA_UART_CONSOLE (&rda_uart_console)
#else
#define RDA_UART_CONSOLE NULL
#endif /* CONFIG_SERIAL_RDA_CONSOLE */
static struct uart_driver rda_uart_driver = {
.owner = THIS_MODULE,
.driver_name = "rda-uart",
.dev_name = RDA_UART_DEV_NAME,
.nr = RDA_UART_PORT_NUM,
.cons = RDA_UART_CONSOLE,
};
static const struct of_device_id rda_uart_dt_matches[] = {
{ .compatible = "rda,8810pl-uart" },
{ }
};
MODULE_DEVICE_TABLE(of, rda_uart_dt_matches);
static int rda_uart_probe(struct platform_device *pdev)
{
struct resource *res_mem;
struct rda_uart_port *rda_port;
int ret, irq;
if (pdev->dev.of_node)
pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
if (pdev->id < 0 || pdev->id >= RDA_UART_PORT_NUM) {
dev_err(&pdev->dev, "id %d out of range\n", pdev->id);
return -EINVAL;
}
res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res_mem) {
dev_err(&pdev->dev, "could not get mem\n");
return -ENODEV;
}
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
if (rda_uart_ports[pdev->id]) {
dev_err(&pdev->dev, "port %d already allocated\n", pdev->id);
return -EBUSY;
}
rda_port = devm_kzalloc(&pdev->dev, sizeof(*rda_port), GFP_KERNEL);
if (!rda_port)
return -ENOMEM;
rda_port->clk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(rda_port->clk)) {
dev_err(&pdev->dev, "could not get clk\n");
return PTR_ERR(rda_port->clk);
}
rda_port->port.dev = &pdev->dev;
rda_port->port.regshift = 0;
rda_port->port.line = pdev->id;
rda_port->port.type = PORT_RDA;
rda_port->port.iotype = UPIO_MEM;
rda_port->port.mapbase = res_mem->start;
rda_port->port.irq = irq;
rda_port->port.uartclk = clk_get_rate(rda_port->clk);
if (rda_port->port.uartclk == 0) {
dev_err(&pdev->dev, "clock rate is zero\n");
return -EINVAL;
}
rda_port->port.flags = UPF_BOOT_AUTOCONF | UPF_IOREMAP |
UPF_LOW_LATENCY;
rda_port->port.x_char = 0;
rda_port->port.fifosize = RDA_UART_TX_FIFO_SIZE;
rda_port->port.ops = &rda_uart_ops;
rda_uart_ports[pdev->id] = rda_port;
platform_set_drvdata(pdev, rda_port);
ret = uart_add_one_port(&rda_uart_driver, &rda_port->port);
if (ret)
rda_uart_ports[pdev->id] = NULL;
return ret;
}
static int rda_uart_remove(struct platform_device *pdev)
{
struct rda_uart_port *rda_port = platform_get_drvdata(pdev);
uart_remove_one_port(&rda_uart_driver, &rda_port->port);
rda_uart_ports[pdev->id] = NULL;
return 0;
}
static struct platform_driver rda_uart_platform_driver = {
.probe = rda_uart_probe,
.remove = rda_uart_remove,
.driver = {
.name = "rda-uart",
.of_match_table = rda_uart_dt_matches,
},
};
static int __init rda_uart_init(void)
{
int ret;
ret = uart_register_driver(&rda_uart_driver);
if (ret)
return ret;
ret = platform_driver_register(&rda_uart_platform_driver);
if (ret)
uart_unregister_driver(&rda_uart_driver);
return ret;
}
static void __exit rda_uart_exit(void)
{
platform_driver_unregister(&rda_uart_platform_driver);
uart_unregister_driver(&rda_uart_driver);
}
module_init(rda_uart_init);
module_exit(rda_uart_exit);
MODULE_AUTHOR("Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>");
MODULE_DESCRIPTION("RDA8810PL serial device driver");
MODULE_LICENSE("GPL");