This patch is removing CDNS_UART_NR_PORTS macro which limits number of ports which can be used. Every instance is registering own struct uart_driver with minor number which corresponds to alias ID (or 0 now). and with 1 uart port. The same alias ID is saved to tty_driver->name_base which is key field for creating ttyPSX name.
Because name_base and minor number are setup already there is no need to setup any port->line number because 0 is the right value. ~# find /proc/tty/ -name "*uartps*" /proc/tty/driver/xuartps0 /proc/tty/driver/xuartps100 Unfortunately this driver is setting up major number to 0 for using dynamic assignment and kernel is allocating different major numbers for every instance instead of using the same major and different minor number. ~# ls -la /dev/ttyPS* crw------- 1 root root 252, 0 Jan 1 03:36 /dev/ttyPS0 crw--w---- 1 root root 253, 1 Jan 1 00:00 /dev/ttyPS1 When major number is not 0. For example 252 then major/minor combinations are in expected form ~# ls -la /dev/ttyPS* crw------- 1 root root 252, 0 Jan 1 04:04 /dev/ttyPS0 crw--w---- 1 root root 252, 1 Jan 1 00:00 /dev/ttyPS1 Signed-off-by: Michal Simek <michal.si...@xilinx.com> --- Changes in v2: - Register one uart_driver with unique minor at probe time This patch not done because id is not unique. This needs to be solved before this patch can be applied. In v1 I have created of_alias_check_id() for that. https://lkml.org/lkml/2018/4/26/551 Also we need to run more testing on this to make sure that everything is working properly. --- drivers/tty/serial/xilinx_uartps.c | 78 +++++++++++++++++++++++--------------- 1 file changed, 48 insertions(+), 30 deletions(-) diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index d76efe8cb3df..82cc17ec7b5d 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -30,8 +30,6 @@ #define CDNS_UART_TTY_NAME "ttyPS" #define CDNS_UART_NAME "xuartps" #define CDNS_UART_MAJOR 0 /* use dynamic node allocation */ -#define CDNS_UART_MINOR 0 /* works best with devtmpfs */ -#define CDNS_UART_NR_PORTS 2 #define CDNS_UART_FIFO_SIZE 64 /* FIFO size */ #define CDNS_UART_REGISTER_SPACE 0x1000 @@ -1247,8 +1245,6 @@ static int __init cdns_uart_console_setup(struct console *co, char *options) return uart_set_options(port, co, baud, parity, bits, flow); } -static struct uart_driver cdns_uart_uart_driver; - static struct console cdns_uart_console = { .name = CDNS_UART_TTY_NAME, .write = cdns_uart_console_write, @@ -1256,7 +1252,6 @@ static int __init cdns_uart_console_setup(struct console *co, char *options) .setup = cdns_uart_console_setup, .flags = CON_PRINTBUFFER, .index = -1, /* Specified on the cmdline (e.g. console=ttyPS ) */ - .data = &cdns_uart_uart_driver, }; #endif /* CONFIG_SERIAL_XILINX_PS_UART_CONSOLE */ @@ -1419,6 +1414,8 @@ static int cdns_uart_probe(struct platform_device *pdev) struct resource *res; struct cdns_uart *cdns_uart_data; const struct of_device_id *match; + struct uart_driver *cdns_uart_uart_driver; + char *driver_name; cdns_uart_data = devm_kzalloc(&pdev->dev, sizeof(*cdns_uart_data), GFP_KERNEL); @@ -1431,32 +1428,49 @@ static int cdns_uart_probe(struct platform_device *pdev) /* Look for a serialN alias */ id = of_alias_get_id(pdev->dev.of_node, "serial"); if (id < 0) + /* + * FIXME this is not enough because if there the next instance + * without alias it will get also id = 0 which is wrong + */ id = 0; - if (id >= CDNS_UART_NR_PORTS) { - dev_err(&pdev->dev, "Cannot get uart_port structure\n"); - return -ENODEV; - } + cdns_uart_uart_driver = devm_kzalloc(&pdev->dev, + sizeof(*cdns_uart_uart_driver), + GFP_KERNEL); + if (!cdns_uart_uart_driver) + return -ENOMEM; + + /* There is a need to use unique driver name */ + driver_name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%s%d", + CDNS_UART_NAME, id); + if (!driver_name) + return -ENOMEM; - if (!cdns_uart_uart_driver.state) { - cdns_uart_uart_driver.owner = THIS_MODULE, - cdns_uart_uart_driver.driver_name = CDNS_UART_NAME, - cdns_uart_uart_driver.dev_name = CDNS_UART_TTY_NAME, - cdns_uart_uart_driver.major = CDNS_UART_MAJOR, - cdns_uart_uart_driver.minor = CDNS_UART_MINOR, - cdns_uart_uart_driver.nr = CDNS_UART_NR_PORTS, + cdns_uart_uart_driver->owner = THIS_MODULE; + cdns_uart_uart_driver->driver_name = driver_name; + cdns_uart_uart_driver->dev_name = CDNS_UART_TTY_NAME; + cdns_uart_uart_driver->major = CDNS_UART_MAJOR; + cdns_uart_uart_driver->minor = id; + cdns_uart_uart_driver->nr = 1; #ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE - cdns_uart_uart_driver.cons = &cdns_uart_console, + cdns_uart_uart_driver->cons = &cdns_uart_console; + cdns_uart_console.data = cdns_uart_uart_driver; #endif - rc = uart_register_driver(&cdns_uart_uart_driver); - if (rc < 0) { - dev_err(&pdev->dev, "Failed to register driver\n"); - return rc; - } + rc = uart_register_driver(cdns_uart_uart_driver); + if (rc < 0) { + dev_err(&pdev->dev, "Failed to register driver\n"); + return rc; } - cdns_uart_data->cdns_uart_driver = &cdns_uart_uart_driver; + /* + * Setting up proper name_base needs to be done after uart + * registration because tty_driver structure is not filled. + * name_base is 0 by default. + */ + cdns_uart_uart_driver->tty_driver->name_base = id; + + cdns_uart_data->cdns_uart_driver = cdns_uart_uart_driver; match = of_match_node(cdns_uart_of_match, pdev->dev.of_node); if (match && match->data) { @@ -1473,7 +1487,8 @@ static int cdns_uart_probe(struct platform_device *pdev) } if (IS_ERR(cdns_uart_data->pclk)) { dev_err(&pdev->dev, "pclk clock not found.\n"); - return PTR_ERR(cdns_uart_data->pclk); + rc = PTR_ERR(cdns_uart_data->pclk); + goto err_out_unregister_driver; } cdns_uart_data->uartclk = devm_clk_get(&pdev->dev, "uart_clk"); @@ -1484,13 +1499,14 @@ static int cdns_uart_probe(struct platform_device *pdev) } if (IS_ERR(cdns_uart_data->uartclk)) { dev_err(&pdev->dev, "uart_clk clock not found.\n"); - return PTR_ERR(cdns_uart_data->uartclk); + rc = PTR_ERR(cdns_uart_data->uartclk); + goto err_out_unregister_driver; } rc = clk_prepare_enable(cdns_uart_data->pclk); if (rc) { dev_err(&pdev->dev, "Unable to enable pclk clock.\n"); - return rc; + goto err_out_unregister_driver; } rc = clk_prepare_enable(cdns_uart_data->uartclk); if (rc) { @@ -1525,7 +1541,6 @@ static int cdns_uart_probe(struct platform_device *pdev) port->flags = UPF_BOOT_AUTOCONF; port->ops = &cdns_uart_ops; port->fifosize = CDNS_UART_FIFO_SIZE; - port->line = id; /* * Register the port. @@ -1552,11 +1567,11 @@ static int cdns_uart_probe(struct platform_device *pdev) * If register_console() don't assign value, then console_port pointer * is cleanup. */ - if (cdns_uart_uart_driver.cons->index == -1) + if (cdns_uart_uart_driver->cons->index == -1) console_port = port; #endif - rc = uart_add_one_port(&cdns_uart_uart_driver, port); + rc = uart_add_one_port(cdns_uart_uart_driver, port); if (rc) { dev_err(&pdev->dev, "uart_add_one_port() failed; err=%i\n", rc); @@ -1565,7 +1580,7 @@ static int cdns_uart_probe(struct platform_device *pdev) #ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE /* This is not port which is used for console that's why clean it up */ - if (cdns_uart_uart_driver.cons->index == -1) + if (cdns_uart_uart_driver->cons->index == -1) console_port = NULL; #endif @@ -1583,6 +1598,8 @@ static int cdns_uart_probe(struct platform_device *pdev) clk_disable_unprepare(cdns_uart_data->uartclk); err_out_clk_dis_pclk: clk_disable_unprepare(cdns_uart_data->pclk); +err_out_unregister_driver: + uart_unregister_driver(cdns_uart_data->cdns_uart_driver); return rc; } @@ -1611,6 +1628,7 @@ static int cdns_uart_remove(struct platform_device *pdev) pm_runtime_disable(&pdev->dev); pm_runtime_set_suspended(&pdev->dev); pm_runtime_dont_use_autosuspend(&pdev->dev); + uart_unregister_driver(cdns_uart_data->cdns_uart_driver); return rc; } -- 1.9.1
