From c64349722d141712d8500b5ad377d3117be46ba8 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Fri, 31 Jul 2015 14:44:23 +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 Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- 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 b968cc5e09bb..15610cb1f295 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 #include #include @@ -29,6 +31,7 @@ #include #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 @@ 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); @@ -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); -- 2.20.1