Michael, can you try this please?
---->8--------------
From: Jakub Kicinski <kubakici@xxxxx>
Date: Thu, 25 Jun 2015 18:17:58 +0200
Subject: [PATCH] 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@xxxxxx>
Signed-off-by: Jakub Kicinski <kubakici@xxxxx>
---
drivers/tty/serial/sc16is7xx.c | 73 ++++++++++++++++++++++++++++--------------
1 file changed, 49 insertions(+), 24 deletions(-)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 5ccc698cbbfa..84fb3e8c3f80 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -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 */
@@ -318,7 +321,6 @@ struct sc16is7xx_one {
};
struct sc16is7xx_port {
- struct uart_driver uart;
struct sc16is7xx_devtype *devtype;
struct regmap *regmap;
struct clk *clk;
@@ -332,6 +334,14 @@ 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)))
@@ -384,6 +394,18 @@ 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)
{
@@ -661,7 +683,7 @@ 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);
}
@@ -1134,23 +1156,13 @@ 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);
@@ -1175,7 +1187,6 @@ static int sc16is7xx_probe(struct device *dev,
for (i = 0; i < devtype->nr_uart; ++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;
@@ -1185,6 +1196,12 @@ 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 */
@@ -1195,7 +1212,7 @@ 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);
}
@@ -1206,8 +1223,11 @@ 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)
@@ -1217,9 +1237,6 @@ out_thread:
#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);
@@ -1237,15 +1254,15 @@ 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);
@@ -1398,7 +1415,14 @@ 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) {
@@ -1427,6 +1451,7 @@ 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);
--
2.1.0
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