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sc16is7xx: support multiple devices 

We currently register the uart driver during device probe
which makes it hard to support more than one chip.
Move the driver registration to module init/exit time and
preallocate space for up to 8 lines (4-8 chips).

Reported-by: Michael Allwright <michael.allwright@upb.de>
Signed-off-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jakub Kicinski 2015-07-31 14:44:23 +02:00 committed by Greg Kroah-Hartman
parent e92a886bf7
commit c64349722d
1 changed files with 49 additions and 24 deletions
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73
drivers/tty/serial/sc16is7xx.c
View File

@ -11,6 +11,8 @@
*
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/bitops.h>
#include <linux/clk.h>
#include <linux/delay.h>
@ -29,6 +31,7 @@
#include <linux/uaccess.h>
#define SC16IS7XX_NAME "sc16is7xx"
#define SC16IS7XX_MAX_DEVS 8
/* SC16IS7XX register definitions */
#define SC16IS7XX_RHR_REG (0x00) /* RX FIFO */
@ -319,7 +322,6 @@ struct sc16is7xx_one {
};
struct sc16is7xx_port {
struct uart_driver uart;
struct sc16is7xx_devtype *devtype;
struct regmap *regmap;
struct clk *clk;
@ -333,6 +335,14 @@ struct sc16is7xx_port {
struct sc16is7xx_one p[0];
};
static unsigned long sc16is7xx_lines;
static struct uart_driver sc16is7xx_uart = {
.owner = THIS_MODULE,
.dev_name = "ttySC",
.nr = SC16IS7XX_MAX_DEVS,
};
#define to_sc16is7xx_port(p,e) ((container_of((p), struct sc16is7xx_port, e)))
#define to_sc16is7xx_one(p,e) ((container_of((p), struct sc16is7xx_one, e)))
@ -394,6 +404,18 @@ static void sc16is7xx_port_update(struct uart_port *port, u8 reg,
mask, val);
}
static int sc16is7xx_alloc_line(void)
{
int i;
BUILD_BUG_ON(SC16IS7XX_MAX_DEVS > BITS_PER_LONG);
for (i = 0; i < SC16IS7XX_MAX_DEVS; i++)
if (!test_and_set_bit(i, &sc16is7xx_lines))
break;
return i;
}
static void sc16is7xx_power(struct uart_port *port, int on)
{
@ -671,7 +693,7 @@ static void sc16is7xx_ist(struct kthread_work *ws)
struct sc16is7xx_port *s = to_sc16is7xx_port(ws, irq_work);
int i;
for (i = 0; i < s->uart.nr; ++i)
for (i = 0; i < s->devtype->nr_uart; ++i)
sc16is7xx_port_irq(s, i);
}
@ -1144,23 +1166,13 @@ static int sc16is7xx_probe(struct device *dev,
s->devtype = devtype;
dev_set_drvdata(dev, s);
/* Register UART driver */
s->uart.owner = THIS_MODULE;
s->uart.dev_name = "ttySC";
s->uart.nr = devtype->nr_uart;
ret = uart_register_driver(&s->uart);
if (ret) {
dev_err(dev, "Registering UART driver failed\n");
goto out_clk;
}
init_kthread_worker(&s->kworker);
init_kthread_work(&s->irq_work, sc16is7xx_ist);
s->kworker_task = kthread_run(kthread_worker_fn, &s->kworker,
"sc16is7xx");
if (IS_ERR(s->kworker_task)) {
ret = PTR_ERR(s->kworker_task);
goto out_uart;
goto out_clk;
}
sched_setscheduler(s->kworker_task, SCHED_FIFO, &sched_param);
@ -1186,7 +1198,6 @@ static int sc16is7xx_probe(struct device *dev,
for (i = 0; i < devtype->nr_uart; ++i) {
s->p[i].line = i;
/* Initialize port data */
s->p[i].port.line = i;
s->p[i].port.dev = dev;
s->p[i].port.irq = irq;
s->p[i].port.type = PORT_SC16IS7XX;
@ -1196,6 +1207,12 @@ static int sc16is7xx_probe(struct device *dev,
s->p[i].port.uartclk = freq;
s->p[i].port.rs485_config = sc16is7xx_config_rs485;
s->p[i].port.ops = &sc16is7xx_ops;
s->p[i].port.line = sc16is7xx_alloc_line();
if (s->p[i].port.line >= SC16IS7XX_MAX_DEVS) {
ret = -ENOMEM;
goto out_ports;
}
/* Disable all interrupts */
sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
/* Disable TX/RX */
@ -1206,7 +1223,7 @@ static int sc16is7xx_probe(struct device *dev,
init_kthread_work(&s->p[i].tx_work, sc16is7xx_tx_proc);
init_kthread_work(&s->p[i].reg_work, sc16is7xx_reg_proc);
/* Register port */
uart_add_one_port(&s->uart, &s->p[i].port);
uart_add_one_port(&sc16is7xx_uart, &s->p[i].port);
/* Go to suspend mode */
sc16is7xx_power(&s->p[i].port, 0);
}
@ -1217,8 +1234,11 @@ static int sc16is7xx_probe(struct device *dev,
if (!ret)
return 0;
for (i = 0; i < s->uart.nr; i++)
uart_remove_one_port(&s->uart, &s->p[i].port);
out_ports:
for (i--; i >= 0; i--) {
uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
clear_bit(s->p[i].port.line, &sc16is7xx_lines);
}
#ifdef CONFIG_GPIOLIB
if (devtype->nr_gpio)
@ -1228,9 +1248,6 @@ static int sc16is7xx_probe(struct device *dev,
#endif
kthread_stop(s->kworker_task);
out_uart:
uart_unregister_driver(&s->uart);
out_clk:
if (!IS_ERR(s->clk))
clk_disable_unprepare(s->clk);
@ -1248,15 +1265,15 @@ static int sc16is7xx_remove(struct device *dev)
gpiochip_remove(&s->gpio);
#endif
for (i = 0; i < s->uart.nr; i++) {
uart_remove_one_port(&s->uart, &s->p[i].port);
for (i = 0; i < s->devtype->nr_uart; i++) {
uart_remove_one_port(&sc16is7xx_uart, &s->p[i].port);
clear_bit(s->p[i].port.line, &sc16is7xx_lines);
sc16is7xx_power(&s->p[i].port, 0);
}
flush_kthread_worker(&s->kworker);
kthread_stop(s->kworker_task);
uart_unregister_driver(&s->uart);
if (!IS_ERR(s->clk))
clk_disable_unprepare(s->clk);
@ -1408,7 +1425,14 @@ MODULE_ALIAS("i2c:sc16is7xx");
static int __init sc16is7xx_init(void)
{
int ret = 0;
int ret;
ret = uart_register_driver(&sc16is7xx_uart);
if (ret) {
pr_err("Registering UART driver failed\n");
return ret;
}
#ifdef CONFIG_SERIAL_SC16IS7XX_I2C
ret = i2c_add_driver(&sc16is7xx_i2c_uart_driver);
if (ret < 0) {
@ -1437,6 +1461,7 @@ static void __exit sc16is7xx_exit(void)
#ifdef CONFIG_SERIAL_SC16IS7XX_SPI
spi_unregister_driver(&sc16is7xx_spi_uart_driver);
#endif
uart_unregister_driver(&sc16is7xx_uart);
}
module_exit(sc16is7xx_exit);