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Commit c6434972 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by Greg Kroah-Hartman
Browse files

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: default avatarMichael Allwright <michael.allwright@upb.de>
Signed-off-by: default avatarJakub Kicinski <kubakici@wp.pl>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent e92a886b

drivers/tty/serial/sc16is7xx.c

+49 −24
Original line number Diff line number Diff line
@@ -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);