From: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx> This patch is removing ULITE_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 ttyULX 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. Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx> Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx> --- drivers/tty/serial/uartlite.c | 251 ++++++++++++++++++++++++++++++------------ 1 file changed, 180 insertions(+), 71 deletions(-) diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c index 4d431a2..1bc3e59 100644 --- a/drivers/tty/serial/uartlite.c +++ b/drivers/tty/serial/uartlite.c @@ -27,7 +27,6 @@ #define ULITE_NAME "ttyUL" #define ULITE_MAJOR 204 #define ULITE_MINOR 187 -#define ULITE_NR_UARTS CONFIG_SERIAL_UARTLITE_NR_UARTS /* --------------------------------------------------------------------- * Register definitions @@ -65,6 +64,7 @@ static struct uart_port *console_port; struct uartlite_data { const struct uartlite_reg_ops *reg_ops; struct clk *clk; + int id; struct uart_driver *ulite_uart_driver; }; @@ -117,7 +117,6 @@ static inline void uart_out32(u32 val, u32 offset, struct uart_port *port) pdata->reg_ops->out(val, port->membase + offset); } -static struct uart_port ulite_ports[ULITE_NR_UARTS]; /* --------------------------------------------------------------------- * Core UART driver operations @@ -535,18 +534,6 @@ static int ulite_console_setup(struct console *co, char *options) return uart_set_options(port, co, baud, parity, bits, flow); } -static struct uart_driver ulite_uart_driver; - -static struct console ulite_console = { - .name = ULITE_NAME, - .write = ulite_console_write, - .device = uart_console_device, - .setup = ulite_console_setup, - .flags = CON_PRINTBUFFER, - .index = -1, /* Specified on the cmdline (e.g. console=ttyUL0 ) */ - .data = &ulite_uart_driver, -}; - static void early_uartlite_putc(struct uart_port *port, int c) { /* @@ -590,18 +577,6 @@ OF_EARLYCON_DECLARE(uartlite_a, "xlnx,xps-uartlite-1.00.a", early_uartlite_setup #endif /* CONFIG_SERIAL_UARTLITE_CONSOLE */ -static struct uart_driver ulite_uart_driver = { - .owner = THIS_MODULE, - .driver_name = "uartlite", - .dev_name = ULITE_NAME, - .major = ULITE_MAJOR, - .minor = ULITE_MINOR, - .nr = ULITE_NR_UARTS, -#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE - .cons = &ulite_console, -#endif -}; - /* --------------------------------------------------------------------- * Port assignment functions (mapping devices to uart_port structures) */ @@ -622,24 +597,9 @@ static int ulite_assign(struct device *dev, int id, u32 base, int irq, struct uart_port *port; int rc; - /* if id = -1; then scan for a free id and use that */ - if (id < 0) { - for (id = 0; id < ULITE_NR_UARTS; id++) - if (ulite_ports[id].mapbase == 0) - break; - } - if (id < 0 || id >= ULITE_NR_UARTS) { - dev_err(dev, "%s%i too large\n", ULITE_NAME, id); - return -EINVAL; - } - - if ((ulite_ports[id].mapbase) && (ulite_ports[id].mapbase != base)) { - dev_err(dev, "cannot assign to %s%i; it is already in use\n", - ULITE_NAME, id); - return -EBUSY; - } - - port = &ulite_ports[id]; + port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL); + if (!port) + return -ENOMEM; spin_lock_init(&port->lock); port->fifosize = 16; @@ -653,7 +613,6 @@ static int ulite_assign(struct device *dev, int id, u32 base, int irq, port->flags = UPF_BOOT_AUTOCONF; port->dev = dev; port->type = PORT_UNKNOWN; - port->line = id; port->private_data = pdata; dev_set_drvdata(dev, port); @@ -783,11 +742,24 @@ static const struct of_device_id ulite_of_match[] = { MODULE_DEVICE_TABLE(of, ulite_of_match); #endif /* CONFIG_OF */ -static int ulite_probe(struct platform_device *pdev) +/* + * Maximum number of instances without alias IDs but if there is alias + * which target "< MAX_UART_INSTANCES" range this ID can't be used. + */ +#define MAX_UART_INSTANCES 256 + +/* Stores static aliases list */ +static DECLARE_BITMAP(alias_bitmap, MAX_UART_INSTANCES); +static int alias_bitmap_initialized; + +/* Stores actual bitmap of allocated IDs with alias IDs together */ +static DECLARE_BITMAP(bitmap, MAX_UART_INSTANCES); +/* Protect bitmap operations to have unique IDs */ +static DEFINE_MUTEX(bitmap_lock); + +static int ulite_get_id(struct platform_device *pdev) { - struct resource *res; - struct uartlite_data *pdata; - int irq, ret; + int ret; int id = pdev->id; #ifdef CONFIG_OF const __be32 *prop; @@ -796,39 +768,158 @@ static int ulite_probe(struct platform_device *pdev) if (prop) id = be32_to_cpup(prop); #endif - if (id < 0) { - /* Look for a serialN alias */ - id = of_alias_get_id(pdev->dev.of_node, "serial"); - if (id < 0) - id = 0; - } - if (!ulite_uart_driver.state) { - dev_dbg(&pdev->dev, "uartlite: calling uart_register_driver()\n"); - ret = uart_register_driver(&ulite_uart_driver); - if (ret < 0) { - dev_err(&pdev->dev, "Failed to register driver\n"); + mutex_lock(&bitmap_lock); + + /* Alias list is stable that's why get alias bitmap only once */ + if (!alias_bitmap_initialized) { + ret = of_alias_get_alias_list(ulite_of_match, "serial", + alias_bitmap, MAX_UART_INSTANCES); + if (ret) { + mutex_unlock(&bitmap_lock); return ret; } + + alias_bitmap_initialized++; } + /* Make sure that alias ID is not taken by instance without alias */ + bitmap_or(bitmap, bitmap, alias_bitmap, MAX_UART_INSTANCES); + + dev_dbg(&pdev->dev, "Alias bitmap: %*pb\n", + MAX_UART_INSTANCES, bitmap); + + /* Look for a serialN alias */ + if (id < 0) + id = of_alias_get_id(pdev->dev.of_node, "serial"); + + if (id < 0) { + dev_warn(&pdev->dev, + "No serial alias passed. Using the first free id\n"); + + /* + * Start with id 0 and check if there is no serial0 alias + * which points to device which is compatible with this driver. + * If alias exists then try next free position. + */ + id = 0; + + for (;;) { + dev_info(&pdev->dev, "Checking id %d\n", id); + id = find_next_zero_bit(bitmap, MAX_UART_INSTANCES, id); + + /* No free empty instance */ + if (id == MAX_UART_INSTANCES) { + dev_err(&pdev->dev, "No free ID\n"); + mutex_unlock(&bitmap_lock); + return -EINVAL; + } + + dev_dbg(&pdev->dev, "The empty id is %d\n", id); + /* Check if ID is empty */ + if (!test_and_set_bit(id, bitmap)) { + /* Break the loop if bit is taken */ + dev_dbg(&pdev->dev, + "Selected ID %d allocation passed\n", + id); + break; + } + dev_dbg(&pdev->dev, + "Selected ID %d allocation failed\n", id); + /* if taking bit fails then try next one */ + id++; + } + } + + mutex_unlock(&bitmap_lock); + + return id; +} + +static int ulite_probe(struct platform_device *pdev) +{ + struct resource *res; + struct uartlite_data *pdata; + int irq, ret; + struct uart_driver *ulite_uart_driver; + char *driver_name; +#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE + struct console *ulite_console; +#endif + pdata = devm_kzalloc(&pdev->dev, sizeof(struct uartlite_data), GFP_KERNEL); if (!pdata) return -ENOMEM; + ulite_uart_driver = devm_kzalloc(&pdev->dev, + sizeof(*ulite_uart_driver), + GFP_KERNEL); + if (!ulite_uart_driver) + return -ENOMEM; + + pdata->id = ulite_get_id(pdev); + if (pdata->id < 0) + return pdata->id; + + /* There is a need to use unique driver name */ + driver_name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%s%d", + ULITE_NAME, pdata->id); + if (!driver_name) { + ret = -ENOMEM; + goto err_out_id; + } + + ulite_uart_driver->owner = THIS_MODULE; + ulite_uart_driver->driver_name = driver_name; + ulite_uart_driver->dev_name = ULITE_NAME; + ulite_uart_driver->major = ULITE_MAJOR; + ulite_uart_driver->minor = pdata->id; + ulite_uart_driver->nr = 1; +#ifdef CONFIG_SERIAL_UARTLITE_CONSOLE + ulite_console = devm_kzalloc(&pdev->dev, sizeof(*ulite_console), + GFP_KERNEL); + if (!ulite_console) { + ret = -ENOMEM; + goto err_out_id; + } + + strncpy(ulite_console->name, ULITE_NAME, + sizeof(ulite_console->name)); + ulite_console->index = pdata->id; + ulite_console->write = ulite_console_write; + ulite_console->device = uart_console_device; + ulite_console->setup = ulite_console_setup; + ulite_console->flags = CON_PRINTBUFFER; + ulite_uart_driver->cons = ulite_console; + ulite_console->data = ulite_uart_driver; +#endif + + dev_dbg(&pdev->dev, "uartlite: calling uart_register_driver()\n"); + ret = uart_register_driver(ulite_uart_driver); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to register driver\n"); + goto err_out_id; + } + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); - if (!res) - return -ENODEV; + if (!res) { + ret = -ENODEV; + goto err_out_unregister_driver; + } irq = platform_get_irq(pdev, 0); - if (irq <= 0) - return -ENXIO; + if (irq <= 0) { + ret = -ENXIO; + goto err_out_unregister_driver; + } pdata->clk = devm_clk_get(&pdev->dev, "s_axi_aclk"); if (IS_ERR(pdata->clk)) { - if (PTR_ERR(pdata->clk) != -ENOENT) - return PTR_ERR(pdata->clk); + if (PTR_ERR(pdata->clk) != -ENOENT) { + ret = PTR_ERR(pdata->clk); + goto err_out_unregister_driver; + } /* * Clock framework support is optional, continue on @@ -837,11 +928,10 @@ static int ulite_probe(struct platform_device *pdev) pdata->clk = NULL; } - pdata->ulite_uart_driver = &ulite_uart_driver; ret = clk_prepare_enable(pdata->clk); if (ret) { dev_err(&pdev->dev, "Failed to prepare clock\n"); - return ret; + goto err_out_unregister_driver; } pm_runtime_use_autosuspend(&pdev->dev); @@ -849,11 +939,27 @@ static int ulite_probe(struct platform_device *pdev) pm_runtime_set_active(&pdev->dev); pm_runtime_enable(&pdev->dev); - ret = ulite_assign(&pdev->dev, id, res->start, irq, pdata); + ulite_uart_driver->tty_driver->name_base = pdata->id; + pdata->ulite_uart_driver = ulite_uart_driver; + ret = ulite_assign(&pdev->dev, pdata->id, res->start, irq, pdata); + if (ret < 0) + goto err_out_clk_disable; pm_runtime_mark_last_busy(&pdev->dev); pm_runtime_put_autosuspend(&pdev->dev); + return 0; +err_out_clk_disable: + clk_disable_unprepare(pdata->clk); + pm_runtime_disable(&pdev->dev); + pm_runtime_set_suspended(&pdev->dev); + pm_runtime_dont_use_autosuspend(&pdev->dev); +err_out_unregister_driver: + uart_unregister_driver(ulite_uart_driver); +err_out_id: + mutex_lock(&bitmap_lock); + clear_bit(pdata->id, bitmap); + mutex_unlock(&bitmap_lock); return ret; } @@ -865,11 +971,16 @@ static int ulite_remove(struct platform_device *pdev) clk_unprepare(pdata->clk); rc = ulite_release(&pdev->dev); + mutex_lock(&bitmap_lock); + clear_bit(pdata->id, bitmap); + mutex_unlock(&bitmap_lock); + #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE if (console_port == port) console_port = NULL; #endif + uart_unregister_driver(pdata->ulite_uart_driver); pm_runtime_disable(&pdev->dev); pm_runtime_set_suspended(&pdev->dev); pm_runtime_dont_use_autosuspend(&pdev->dev); @@ -903,8 +1014,6 @@ static int __init ulite_init(void) static void __exit ulite_exit(void) { platform_driver_unregister(&ulite_platform_driver); - if (ulite_uart_driver.state) - uart_unregister_driver(&ulite_uart_driver); } module_init(ulite_init); -- 2.1.1