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linux-zen-server/drivers/tty/serial/st-asc.c

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Initial commit
2023-08-30 17:53:23 +02:00
// SPDX-License-Identifier: GPL-2.0+
/*
* st-asc.c: ST Asynchronous serial controller (ASC) driver
*
* Copyright (C) 2003-2013 STMicroelectronics (R&D) Limited
*/
#include <linux/module.h>
#include <linux/serial.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/serial_core.h>
#include <linux/clk.h>
#include <linux/gpio/consumer.h>
#define DRIVER_NAME "st-asc"
#define ASC_SERIAL_NAME "ttyAS"
#define ASC_FIFO_SIZE 16
#define ASC_MAX_PORTS 8
/* Pinctrl states */
#define DEFAULT 0
#define NO_HW_FLOWCTRL 1
struct asc_port {
struct uart_port port;
struct gpio_desc *rts;
struct clk *clk;
struct pinctrl *pinctrl;
struct pinctrl_state *states[2];
unsigned int hw_flow_control:1;
unsigned int force_m1:1;
};
static struct asc_port asc_ports[ASC_MAX_PORTS];
static struct uart_driver asc_uart_driver;
/*---- UART Register definitions ------------------------------*/
/* Register offsets */
#define ASC_BAUDRATE 0x00
#define ASC_TXBUF 0x04
#define ASC_RXBUF 0x08
#define ASC_CTL 0x0C
#define ASC_INTEN 0x10
#define ASC_STA 0x14
#define ASC_GUARDTIME 0x18
#define ASC_TIMEOUT 0x1C
#define ASC_TXRESET 0x20
#define ASC_RXRESET 0x24
#define ASC_RETRIES 0x28
/* ASC_RXBUF */
#define ASC_RXBUF_PE 0x100
#define ASC_RXBUF_FE 0x200
/*
* Some of status comes from higher bits of the character and some come from
* the status register. Combining both of them in to single status using dummy
* bits.
*/
#define ASC_RXBUF_DUMMY_RX 0x10000
#define ASC_RXBUF_DUMMY_BE 0x20000
#define ASC_RXBUF_DUMMY_OE 0x40000
/* ASC_CTL */
#define ASC_CTL_MODE_MSK 0x0007
#define ASC_CTL_MODE_8BIT 0x0001
#define ASC_CTL_MODE_7BIT_PAR 0x0003
#define ASC_CTL_MODE_9BIT 0x0004
#define ASC_CTL_MODE_8BIT_WKUP 0x0005
#define ASC_CTL_MODE_8BIT_PAR 0x0007
#define ASC_CTL_STOP_MSK 0x0018
#define ASC_CTL_STOP_HALFBIT 0x0000
#define ASC_CTL_STOP_1BIT 0x0008
#define ASC_CTL_STOP_1_HALFBIT 0x0010
#define ASC_CTL_STOP_2BIT 0x0018
#define ASC_CTL_PARITYODD 0x0020
#define ASC_CTL_LOOPBACK 0x0040
#define ASC_CTL_RUN 0x0080
#define ASC_CTL_RXENABLE 0x0100
#define ASC_CTL_SCENABLE 0x0200
#define ASC_CTL_FIFOENABLE 0x0400
#define ASC_CTL_CTSENABLE 0x0800
#define ASC_CTL_BAUDMODE 0x1000
/* ASC_GUARDTIME */
#define ASC_GUARDTIME_MSK 0x00FF
/* ASC_INTEN */
#define ASC_INTEN_RBE 0x0001
#define ASC_INTEN_TE 0x0002
#define ASC_INTEN_THE 0x0004
#define ASC_INTEN_PE 0x0008
#define ASC_INTEN_FE 0x0010
#define ASC_INTEN_OE 0x0020
#define ASC_INTEN_TNE 0x0040
#define ASC_INTEN_TOI 0x0080
#define ASC_INTEN_RHF 0x0100
/* ASC_RETRIES */
#define ASC_RETRIES_MSK 0x00FF
/* ASC_RXBUF */
#define ASC_RXBUF_MSK 0x03FF
/* ASC_STA */
#define ASC_STA_RBF 0x0001
#define ASC_STA_TE 0x0002
#define ASC_STA_THE 0x0004
#define ASC_STA_PE 0x0008
#define ASC_STA_FE 0x0010
#define ASC_STA_OE 0x0020
#define ASC_STA_TNE 0x0040
#define ASC_STA_TOI 0x0080
#define ASC_STA_RHF 0x0100
#define ASC_STA_TF 0x0200
#define ASC_STA_NKD 0x0400
/* ASC_TIMEOUT */
#define ASC_TIMEOUT_MSK 0x00FF
/* ASC_TXBUF */
#define ASC_TXBUF_MSK 0x01FF
/*---- Inline function definitions ---------------------------*/
static inline struct asc_port *to_asc_port(struct uart_port *port)
{
return container_of(port, struct asc_port, port);
}
static inline u32 asc_in(struct uart_port *port, u32 offset)
{
#ifdef readl_relaxed
return readl_relaxed(port->membase + offset);
#else
return readl(port->membase + offset);
#endif
}
static inline void asc_out(struct uart_port *port, u32 offset, u32 value)
{
#ifdef writel_relaxed
writel_relaxed(value, port->membase + offset);
#else
writel(value, port->membase + offset);
#endif
}
/*
* Some simple utility functions to enable and disable interrupts.
* Note that these need to be called with interrupts disabled.
*/
static inline void asc_disable_tx_interrupts(struct uart_port *port)
{
u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_THE;
asc_out(port, ASC_INTEN, intenable);
(void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */
}
static inline void asc_enable_tx_interrupts(struct uart_port *port)
{
u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_THE;
asc_out(port, ASC_INTEN, intenable);
}
static inline void asc_disable_rx_interrupts(struct uart_port *port)
{
u32 intenable = asc_in(port, ASC_INTEN) & ~ASC_INTEN_RBE;
asc_out(port, ASC_INTEN, intenable);
(void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */
}
static inline void asc_enable_rx_interrupts(struct uart_port *port)
{
u32 intenable = asc_in(port, ASC_INTEN) | ASC_INTEN_RBE;
asc_out(port, ASC_INTEN, intenable);
}
static inline u32 asc_txfifo_is_empty(struct uart_port *port)
{
return asc_in(port, ASC_STA) & ASC_STA_TE;
}
static inline u32 asc_txfifo_is_half_empty(struct uart_port *port)
{
return asc_in(port, ASC_STA) & ASC_STA_THE;
}
static inline const char *asc_port_name(struct uart_port *port)
{
return to_platform_device(port->dev)->name;
}
/*----------------------------------------------------------------------*/
/*
* This section contains code to support the use of the ASC as a
* generic serial port.
*/
static inline unsigned asc_hw_txroom(struct uart_port *port)
{
u32 status = asc_in(port, ASC_STA);
if (status & ASC_STA_THE)
return port->fifosize / 2;
else if (!(status & ASC_STA_TF))
return 1;
return 0;
}
/*
* Start transmitting chars.
* This is called from both interrupt and task level.
* Either way interrupts are disabled.
*/
static void asc_transmit_chars(struct uart_port *port)
{
u8 ch;
uart_port_tx_limited(port, ch, asc_hw_txroom(port),
true,
asc_out(port, ASC_TXBUF, ch),
({}));
}
static void asc_receive_chars(struct uart_port *port)
{
struct tty_port *tport = &port->state->port;
unsigned long status, mode;
unsigned long c = 0;
char flag;
bool ignore_pe = false;
/*
* Datasheet states: If the MODE field selects an 8-bit frame then
* this [parity error] bit is undefined. Software should ignore this
* bit when reading 8-bit frames.
*/
mode = asc_in(port, ASC_CTL) & ASC_CTL_MODE_MSK;
if (mode == ASC_CTL_MODE_8BIT || mode == ASC_CTL_MODE_8BIT_PAR)
ignore_pe = true;
if (irqd_is_wakeup_set(irq_get_irq_data(port->irq)))
pm_wakeup_event(tport->tty->dev, 0);
while ((status = asc_in(port, ASC_STA)) & ASC_STA_RBF) {
c = asc_in(port, ASC_RXBUF) | ASC_RXBUF_DUMMY_RX;
flag = TTY_NORMAL;
port->icount.rx++;
if (status & ASC_STA_OE || c & ASC_RXBUF_FE ||
(c & ASC_RXBUF_PE && !ignore_pe)) {
if (c & ASC_RXBUF_FE) {
if (c == (ASC_RXBUF_FE | ASC_RXBUF_DUMMY_RX)) {
port->icount.brk++;
if (uart_handle_break(port))
continue;
c |= ASC_RXBUF_DUMMY_BE;
} else {
port->icount.frame++;
}
} else if (c & ASC_RXBUF_PE) {
port->icount.parity++;
}
/*
* Reading any data from the RX FIFO clears the
* overflow error condition.
*/
if (status & ASC_STA_OE) {
port->icount.overrun++;
c |= ASC_RXBUF_DUMMY_OE;
}
c &= port->read_status_mask;
if (c & ASC_RXBUF_DUMMY_BE)
flag = TTY_BREAK;
else if (c & ASC_RXBUF_PE)
flag = TTY_PARITY;
else if (c & ASC_RXBUF_FE)
flag = TTY_FRAME;
}
if (uart_handle_sysrq_char(port, c & 0xff))
continue;
uart_insert_char(port, c, ASC_RXBUF_DUMMY_OE, c & 0xff, flag);
}
/* Tell the rest of the system the news. New characters! */
tty_flip_buffer_push(tport);
}
static irqreturn_t asc_interrupt(int irq, void *ptr)
{
struct uart_port *port = ptr;
u32 status;
spin_lock(&port->lock);
status = asc_in(port, ASC_STA);
if (status & ASC_STA_RBF) {
/* Receive FIFO not empty */
asc_receive_chars(port);
}
if ((status & ASC_STA_THE) &&
(asc_in(port, ASC_INTEN) & ASC_INTEN_THE)) {
/* Transmitter FIFO at least half empty */
asc_transmit_chars(port);
}
spin_unlock(&port->lock);
return IRQ_HANDLED;
}
/*----------------------------------------------------------------------*/
/*
* UART Functions
*/
static unsigned int asc_tx_empty(struct uart_port *port)
{
return asc_txfifo_is_empty(port) ? TIOCSER_TEMT : 0;
}
static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
struct asc_port *ascport = to_asc_port(port);
/*
* This routine is used for seting signals of: DTR, DCD, CTS and RTS.
* We use ASC's hardware for CTS/RTS when hardware flow-control is
* enabled, however if the RTS line is required for another purpose,
* commonly controlled using HUP from userspace, then we need to toggle
* it manually, using GPIO.
*
* Some boards also have DTR and DCD implemented using PIO pins, code to
* do this should be hooked in here.
*/
if (!ascport->rts)
return;
/* If HW flow-control is enabled, we can't fiddle with the RTS line */
if (asc_in(port, ASC_CTL) & ASC_CTL_CTSENABLE)
return;
gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS);
}
static unsigned int asc_get_mctrl(struct uart_port *port)
{
/*
* This routine is used for geting signals of: DTR, DCD, DSR, RI,
* and CTS/RTS
*/
return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
}
/* There are probably characters waiting to be transmitted. */
static void asc_start_tx(struct uart_port *port)
{
struct circ_buf *xmit = &port->state->xmit;
if (!uart_circ_empty(xmit))
asc_enable_tx_interrupts(port);
}
/* Transmit stop */
static void asc_stop_tx(struct uart_port *port)
{
asc_disable_tx_interrupts(port);
}
/* Receive stop */
static void asc_stop_rx(struct uart_port *port)
{
asc_disable_rx_interrupts(port);
}
/* Handle breaks - ignored by us */
static void asc_break_ctl(struct uart_port *port, int break_state)
{
/* Nothing here yet .. */
}
/*
* Enable port for reception.
*/
static int asc_startup(struct uart_port *port)
{
if (request_irq(port->irq, asc_interrupt, 0,
asc_port_name(port), port)) {
dev_err(port->dev, "cannot allocate irq.\n");
return -ENODEV;
}
asc_transmit_chars(port);
asc_enable_rx_interrupts(port);
return 0;
}
static void asc_shutdown(struct uart_port *port)
{
asc_disable_tx_interrupts(port);
asc_disable_rx_interrupts(port);
free_irq(port->irq, port);
}
static void asc_pm(struct uart_port *port, unsigned int state,
unsigned int oldstate)
{
struct asc_port *ascport = to_asc_port(port);
unsigned long flags;
u32 ctl;
switch (state) {
case UART_PM_STATE_ON:
clk_prepare_enable(ascport->clk);
break;
case UART_PM_STATE_OFF:
/*
* Disable the ASC baud rate generator, which is as close as
* we can come to turning it off. Note this is not called with
* the port spinlock held.
*/
spin_lock_irqsave(&port->lock, flags);
ctl = asc_in(port, ASC_CTL) & ~ASC_CTL_RUN;
asc_out(port, ASC_CTL, ctl);
spin_unlock_irqrestore(&port->lock, flags);
clk_disable_unprepare(ascport->clk);
break;
}
}
static void asc_set_termios(struct uart_port *port, struct ktermios *termios,
const struct ktermios *old)
{
struct asc_port *ascport = to_asc_port(port);
struct gpio_desc *gpiod;
unsigned int baud;
u32 ctrl_val;
tcflag_t cflag;
unsigned long flags;
/* Update termios to reflect hardware capabilities */
termios->c_cflag &= ~(CMSPAR |
(ascport->hw_flow_control ? 0 : CRTSCTS));
port->uartclk = clk_get_rate(ascport->clk);
baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk/16);
cflag = termios->c_cflag;
spin_lock_irqsave(&port->lock, flags);
/* read control register */
ctrl_val = asc_in(port, ASC_CTL);
/* stop serial port and reset value */
asc_out(port, ASC_CTL, (ctrl_val & ~ASC_CTL_RUN));
ctrl_val = ASC_CTL_RXENABLE | ASC_CTL_FIFOENABLE;
/* reset fifo rx & tx */
asc_out(port, ASC_TXRESET, 1);
asc_out(port, ASC_RXRESET, 1);
/* set character length */
if ((cflag & CSIZE) == CS7) {
ctrl_val |= ASC_CTL_MODE_7BIT_PAR;
cflag |= PARENB;
} else {
ctrl_val |= (cflag & PARENB) ? ASC_CTL_MODE_8BIT_PAR :
ASC_CTL_MODE_8BIT;
cflag &= ~CSIZE;
cflag |= CS8;
}
termios->c_cflag = cflag;
/* set stop bit */
ctrl_val |= (cflag & CSTOPB) ? ASC_CTL_STOP_2BIT : ASC_CTL_STOP_1BIT;
/* odd parity */
if (cflag & PARODD)
ctrl_val |= ASC_CTL_PARITYODD;
/* hardware flow control */
if ((cflag & CRTSCTS)) {
ctrl_val |= ASC_CTL_CTSENABLE;
/* If flow-control selected, stop handling RTS manually */
if (ascport->rts) {
devm_gpiod_put(port->dev, ascport->rts);
ascport->rts = NULL;
pinctrl_select_state(ascport->pinctrl,
ascport->states[DEFAULT]);
}
} else {
/* If flow-control disabled, it's safe to handle RTS manually */
if (!ascport->rts && ascport->states[NO_HW_FLOWCTRL]) {
pinctrl_select_state(ascport->pinctrl,
ascport->states[NO_HW_FLOWCTRL]);
gpiod = devm_gpiod_get(port->dev, "rts", GPIOD_OUT_LOW);
if (!IS_ERR(gpiod)) {
gpiod_set_consumer_name(gpiod,
port->dev->of_node->name);
ascport->rts = gpiod;
}
}
}
if ((baud < 19200) && !ascport->force_m1) {
asc_out(port, ASC_BAUDRATE, (port->uartclk / (16 * baud)));
} else {
/*
* MODE 1: recommended for high bit rates (above 19.2K)
*
* baudrate * 16 * 2^16
* ASCBaudRate = ------------------------
* inputclock
*
* To keep maths inside 64bits, we divide inputclock by 16.
*/
u64 dividend = (u64)baud * (1 << 16);
do_div(dividend, port->uartclk / 16);
asc_out(port, ASC_BAUDRATE, dividend);
ctrl_val |= ASC_CTL_BAUDMODE;
}
uart_update_timeout(port, cflag, baud);
ascport->port.read_status_mask = ASC_RXBUF_DUMMY_OE;
if (termios->c_iflag & INPCK)
ascport->port.read_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE;
if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK))
ascport->port.read_status_mask |= ASC_RXBUF_DUMMY_BE;
/*
* Characters to ignore
*/
ascport->port.ignore_status_mask = 0;
if (termios->c_iflag & IGNPAR)
ascport->port.ignore_status_mask |= ASC_RXBUF_FE | ASC_RXBUF_PE;
if (termios->c_iflag & IGNBRK) {
ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_BE;
/*
* If we're ignoring parity and break indicators,
* ignore overruns too (for real raw support).
*/
if (termios->c_iflag & IGNPAR)
ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_OE;
}
/*
* Ignore all characters if CREAD is not set.
*/
if (!(termios->c_cflag & CREAD))
ascport->port.ignore_status_mask |= ASC_RXBUF_DUMMY_RX;
/* Set the timeout */
asc_out(port, ASC_TIMEOUT, 20);
/* write final value and enable port */
asc_out(port, ASC_CTL, (ctrl_val | ASC_CTL_RUN));
spin_unlock_irqrestore(&port->lock, flags);
}
static const char *asc_type(struct uart_port *port)
{
return (port->type == PORT_ASC) ? DRIVER_NAME : NULL;
}
static void asc_release_port(struct uart_port *port)
{
}
static int asc_request_port(struct uart_port *port)
{
return 0;
}
/*
* Called when the port is opened, and UPF_BOOT_AUTOCONF flag is set
* Set type field if successful
*/
static void asc_config_port(struct uart_port *port, int flags)
{
if ((flags & UART_CONFIG_TYPE))
port->type = PORT_ASC;
}
static int
asc_verify_port(struct uart_port *port, struct serial_struct *ser)
{
/* No user changeable parameters */
return -EINVAL;
}
#ifdef CONFIG_CONSOLE_POLL
/*
* Console polling routines for writing and reading from the uart while
* in an interrupt or debug context (i.e. kgdb).
*/
static int asc_get_poll_char(struct uart_port *port)
{
if (!(asc_in(port, ASC_STA) & ASC_STA_RBF))
return NO_POLL_CHAR;
return asc_in(port, ASC_RXBUF);
}
static void asc_put_poll_char(struct uart_port *port, unsigned char c)
{
while (!asc_txfifo_is_half_empty(port))
cpu_relax();
asc_out(port, ASC_TXBUF, c);
}
#endif /* CONFIG_CONSOLE_POLL */
/*---------------------------------------------------------------------*/
static const struct uart_ops asc_uart_ops = {
.tx_empty = asc_tx_empty,
.set_mctrl = asc_set_mctrl,
.get_mctrl = asc_get_mctrl,
.start_tx = asc_start_tx,
.stop_tx = asc_stop_tx,
.stop_rx = asc_stop_rx,
.break_ctl = asc_break_ctl,
.startup = asc_startup,
.shutdown = asc_shutdown,
.set_termios = asc_set_termios,
.type = asc_type,
.release_port = asc_release_port,
.request_port = asc_request_port,
.config_port = asc_config_port,
.verify_port = asc_verify_port,
.pm = asc_pm,
#ifdef CONFIG_CONSOLE_POLL
.poll_get_char = asc_get_poll_char,
.poll_put_char = asc_put_poll_char,
#endif /* CONFIG_CONSOLE_POLL */
};
static int asc_init_port(struct asc_port *ascport,
struct platform_device *pdev)
{
struct uart_port *port = &ascport->port;
struct resource *res;
int ret;
port->iotype = UPIO_MEM;
port->flags = UPF_BOOT_AUTOCONF;
port->ops = &asc_uart_ops;
port->fifosize = ASC_FIFO_SIZE;
port->dev = &pdev->dev;
port->irq = platform_get_irq(pdev, 0);
port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_ST_ASC_CONSOLE);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
port->membase = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(port->membase))
return PTR_ERR(port->membase);
port->mapbase = res->start;
spin_lock_init(&port->lock);
ascport->clk = devm_clk_get(&pdev->dev, NULL);
if (WARN_ON(IS_ERR(ascport->clk)))
return -EINVAL;
/* ensure that clk rate is correct by enabling the clk */
clk_prepare_enable(ascport->clk);
ascport->port.uartclk = clk_get_rate(ascport->clk);
WARN_ON(ascport->port.uartclk == 0);
clk_disable_unprepare(ascport->clk);
ascport->pinctrl = devm_pinctrl_get(&pdev->dev);
if (IS_ERR(ascport->pinctrl)) {
ret = PTR_ERR(ascport->pinctrl);
dev_err(&pdev->dev, "Failed to get Pinctrl: %d\n", ret);
return ret;
}
ascport->states[DEFAULT] =
pinctrl_lookup_state(ascport->pinctrl, "default");
if (IS_ERR(ascport->states[DEFAULT])) {
ret = PTR_ERR(ascport->states[DEFAULT]);
dev_err(&pdev->dev,
"Failed to look up Pinctrl state 'default': %d\n", ret);
return ret;
}
/* "no-hw-flowctrl" state is optional */
ascport->states[NO_HW_FLOWCTRL] =
pinctrl_lookup_state(ascport->pinctrl, "no-hw-flowctrl");
if (IS_ERR(ascport->states[NO_HW_FLOWCTRL]))
ascport->states[NO_HW_FLOWCTRL] = NULL;
return 0;
}
static struct asc_port *asc_of_get_asc_port(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
int id;
if (!np)
return NULL;
id = of_alias_get_id(np, "serial");
if (id < 0)
id = of_alias_get_id(np, ASC_SERIAL_NAME);
if (id < 0)
id = 0;
if (WARN_ON(id >= ASC_MAX_PORTS))
return NULL;
asc_ports[id].hw_flow_control = of_property_read_bool(np,
"uart-has-rtscts");
asc_ports[id].force_m1 = of_property_read_bool(np, "st,force_m1");
asc_ports[id].port.line = id;
asc_ports[id].rts = NULL;
return &asc_ports[id];
}
#ifdef CONFIG_OF
static const struct of_device_id asc_match[] = {
{ .compatible = "st,asc", },
{},
};
MODULE_DEVICE_TABLE(of, asc_match);
#endif
static int asc_serial_probe(struct platform_device *pdev)
{
int ret;
struct asc_port *ascport;
ascport = asc_of_get_asc_port(pdev);
if (!ascport)
return -ENODEV;
ret = asc_init_port(ascport, pdev);
if (ret)
return ret;
ret = uart_add_one_port(&asc_uart_driver, &ascport->port);
if (ret)
return ret;
platform_set_drvdata(pdev, &ascport->port);
return 0;
}
static int asc_serial_remove(struct platform_device *pdev)
{
struct uart_port *port = platform_get_drvdata(pdev);
return uart_remove_one_port(&asc_uart_driver, port);
}
#ifdef CONFIG_PM_SLEEP
static int asc_serial_suspend(struct device *dev)
{
struct uart_port *port = dev_get_drvdata(dev);
return uart_suspend_port(&asc_uart_driver, port);
}
static int asc_serial_resume(struct device *dev)
{
struct uart_port *port = dev_get_drvdata(dev);
return uart_resume_port(&asc_uart_driver, port);
}
#endif /* CONFIG_PM_SLEEP */
/*----------------------------------------------------------------------*/
#ifdef CONFIG_SERIAL_ST_ASC_CONSOLE
static void asc_console_putchar(struct uart_port *port, unsigned char ch)
{
unsigned int timeout = 1000000;
/* Wait for upto 1 second in case flow control is stopping us. */
while (--timeout && !asc_txfifo_is_half_empty(port))
udelay(1);
asc_out(port, ASC_TXBUF, ch);
}
/*
* Print a string to the serial port trying not to disturb
* any possible real use of the port...
*/
static void asc_console_write(struct console *co, const char *s, unsigned count)
{
struct uart_port *port = &asc_ports[co->index].port;
unsigned long flags;
unsigned long timeout = 1000000;
int locked = 1;
u32 intenable;
if (port->sysrq)
locked = 0; /* asc_interrupt has already claimed the lock */
else if (oops_in_progress)
locked = spin_trylock_irqsave(&port->lock, flags);
else
spin_lock_irqsave(&port->lock, flags);
/*
* Disable interrupts so we don't get the IRQ line bouncing
* up and down while interrupts are disabled.
*/
intenable = asc_in(port, ASC_INTEN);
asc_out(port, ASC_INTEN, 0);
(void)asc_in(port, ASC_INTEN); /* Defeat bus write posting */
uart_console_write(port, s, count, asc_console_putchar);
while (--timeout && !asc_txfifo_is_empty(port))
udelay(1);
asc_out(port, ASC_INTEN, intenable);
if (locked)
spin_unlock_irqrestore(&port->lock, flags);
}
static int asc_console_setup(struct console *co, char *options)
{
struct asc_port *ascport;
int baud = 115200;
int bits = 8;
int parity = 'n';
int flow = 'n';
if (co->index >= ASC_MAX_PORTS)
return -ENODEV;
ascport = &asc_ports[co->index];
/*
* This driver does not support early console initialization
* (use ARM early printk support instead), so we only expect
* this to be called during the uart port registration when the
* driver gets probed and the port should be mapped at that point.
*/
if (ascport->port.mapbase == 0 || ascport->port.membase == NULL)
return -ENXIO;
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
return uart_set_options(&ascport->port, co, baud, parity, bits, flow);
}
static struct console asc_console = {
.name = ASC_SERIAL_NAME,
.device = uart_console_device,
.write = asc_console_write,
.setup = asc_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &asc_uart_driver,
};
#define ASC_SERIAL_CONSOLE (&asc_console)
#else
#define ASC_SERIAL_CONSOLE NULL
#endif /* CONFIG_SERIAL_ST_ASC_CONSOLE */
static struct uart_driver asc_uart_driver = {
.owner = THIS_MODULE,
.driver_name = DRIVER_NAME,
.dev_name = ASC_SERIAL_NAME,
.major = 0,
.minor = 0,
.nr = ASC_MAX_PORTS,
.cons = ASC_SERIAL_CONSOLE,
};
static const struct dev_pm_ops asc_serial_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(asc_serial_suspend, asc_serial_resume)
};
static struct platform_driver asc_serial_driver = {
.probe = asc_serial_probe,
.remove = asc_serial_remove,
.driver = {
.name = DRIVER_NAME,
.pm = &asc_serial_pm_ops,
.of_match_table = of_match_ptr(asc_match),
},
};
static int __init asc_init(void)
{
int ret;
static const char banner[] __initconst =
KERN_INFO "STMicroelectronics ASC driver initialized\n";
printk(banner);
ret = uart_register_driver(&asc_uart_driver);
if (ret)
return ret;
ret = platform_driver_register(&asc_serial_driver);
if (ret)
uart_unregister_driver(&asc_uart_driver);
return ret;
}
static void __exit asc_exit(void)
{
platform_driver_unregister(&asc_serial_driver);
uart_unregister_driver(&asc_uart_driver);
}
module_init(asc_init);
module_exit(asc_exit);
MODULE_ALIAS("platform:" DRIVER_NAME);
MODULE_AUTHOR("STMicroelectronics (R&D) Limited");
MODULE_DESCRIPTION("STMicroelectronics ASC serial port driver");
MODULE_LICENSE("GPL");