diff options
Diffstat (limited to 'drivers/tty/serial/uartlite.c')
| -rw-r--r-- | drivers/tty/serial/uartlite.c | 88 |
1 files changed, 62 insertions, 26 deletions
diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c index a5f15f22d9ef..dfc1ba4e1572 100644 --- a/drivers/tty/serial/uartlite.c +++ b/drivers/tty/serial/uartlite.c @@ -17,11 +17,13 @@ #include <linux/interrupt.h> #include <linux/init.h> #include <linux/io.h> +#include <linux/iopoll.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_device.h> #include <linux/of_platform.h> #include <linux/clk.h> +#include <linux/pm_runtime.h> #define ULITE_NAME "ttyUL" #define ULITE_MAJOR 204 @@ -54,6 +56,7 @@ #define ULITE_CONTROL_RST_TX 0x01 #define ULITE_CONTROL_RST_RX 0x02 #define ULITE_CONTROL_IE 0x10 +#define UART_AUTOSUSPEND_TIMEOUT 3000 /* ms */ /* Static pointer to console port */ #ifdef CONFIG_SERIAL_UARTLITE_CONSOLE @@ -390,12 +393,16 @@ static int ulite_verify_port(struct uart_port *port, struct serial_struct *ser) static void ulite_pm(struct uart_port *port, unsigned int state, unsigned int oldstate) { - struct uartlite_data *pdata = port->private_data; + int ret; - if (!state) - clk_enable(pdata->clk); - else - clk_disable(pdata->clk); + if (!state) { + ret = pm_runtime_get_sync(port->dev); + if (ret < 0) + dev_err(port->dev, "Failed to enable clocks\n"); + } else { + pm_runtime_mark_last_busy(port->dev); + pm_runtime_put_autosuspend(port->dev); + } } #ifdef CONFIG_CONSOLE_POLL @@ -448,24 +455,15 @@ static const struct uart_ops ulite_ops = { static void ulite_console_wait_tx(struct uart_port *port) { u8 val; - unsigned long timeout; /* * Spin waiting for TX fifo to have space available. * When using the Microblaze Debug Module this can take up to 1s */ - timeout = jiffies + msecs_to_jiffies(1000); - while (1) { - val = uart_in32(ULITE_STATUS, port); - if ((val & ULITE_STATUS_TXFULL) == 0) - break; - if (time_after(jiffies, timeout)) { - dev_warn(port->dev, - "timeout waiting for TX buffer empty\n"); - break; - } - cpu_relax(); - } + if (read_poll_timeout_atomic(uart_in32, val, !(val & ULITE_STATUS_TXFULL), + 0, 1000000, false, ULITE_STATUS, port)) + dev_warn(port->dev, + "timeout waiting for TX buffer empty\n"); } static void ulite_console_putchar(struct uart_port *port, int ch) @@ -555,16 +553,15 @@ static void early_uartlite_putc(struct uart_port *port, int c) * This limit is pretty arbitrary, unless we are at about 10 baud * we'll never timeout on a working UART. */ - unsigned retries = 1000000; - /* read status bit - 0x8 offset */ - while (--retries && (readl(port->membase + 8) & (1 << 3))) + + while (--retries && + (readl(port->membase + ULITE_STATUS) & ULITE_STATUS_TXFULL)) ; /* Only attempt the iowrite if we didn't timeout */ - /* write to TX_FIFO - 0x4 offset */ if (retries) - writel(c & 0xff, port->membase + 4); + writel(c & 0xff, port->membase + ULITE_TX); } static void early_uartlite_write(struct console *console, @@ -719,11 +716,38 @@ static int __maybe_unused ulite_resume(struct device *dev) return 0; } +static int __maybe_unused ulite_runtime_suspend(struct device *dev) +{ + struct uart_port *port = dev_get_drvdata(dev); + struct uartlite_data *pdata = port->private_data; + + clk_disable(pdata->clk); + return 0; +}; + +static int __maybe_unused ulite_runtime_resume(struct device *dev) +{ + struct uart_port *port = dev_get_drvdata(dev); + struct uartlite_data *pdata = port->private_data; + int ret; + + ret = clk_enable(pdata->clk); + if (ret) { + dev_err(dev, "Cannot enable clock.\n"); + return ret; + } + return 0; +} + /* --------------------------------------------------------------------- * Platform bus binding */ -static SIMPLE_DEV_PM_OPS(ulite_pm_ops, ulite_suspend, ulite_resume); +static const struct dev_pm_ops ulite_pm_ops = { + SET_SYSTEM_SLEEP_PM_OPS(ulite_suspend, ulite_resume) + SET_RUNTIME_PM_OPS(ulite_runtime_suspend, + ulite_runtime_resume, NULL) +}; #if defined(CONFIG_OF) /* Match table for of_platform binding */ @@ -779,18 +803,25 @@ static int ulite_probe(struct platform_device *pdev) return ret; } + pm_runtime_use_autosuspend(&pdev->dev); + pm_runtime_set_autosuspend_delay(&pdev->dev, UART_AUTOSUSPEND_TIMEOUT); + pm_runtime_set_active(&pdev->dev); + pm_runtime_enable(&pdev->dev); + 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"); + clk_disable_unprepare(pdata->clk); return ret; } } ret = ulite_assign(&pdev->dev, id, res->start, irq, pdata); - clk_disable(pdata->clk); + pm_runtime_mark_last_busy(&pdev->dev); + pm_runtime_put_autosuspend(&pdev->dev); return ret; } @@ -799,9 +830,14 @@ static int ulite_remove(struct platform_device *pdev) { struct uart_port *port = dev_get_drvdata(&pdev->dev); struct uartlite_data *pdata = port->private_data; + int rc; clk_disable_unprepare(pdata->clk); - return ulite_release(&pdev->dev); + rc = ulite_release(&pdev->dev); + pm_runtime_disable(&pdev->dev); + pm_runtime_set_suspended(&pdev->dev); + pm_runtime_dont_use_autosuspend(&pdev->dev); + return rc; } /* work with hotplug and coldplug */ |