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path: root/kernel/drivers/tty/serial/8250/8250_mtk.c
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Diffstat (limited to 'kernel/drivers/tty/serial/8250/8250_mtk.c')
-rw-r--r--kernel/drivers/tty/serial/8250/8250_mtk.c119
1 files changed, 75 insertions, 44 deletions
diff --git a/kernel/drivers/tty/serial/8250/8250_mtk.c b/kernel/drivers/tty/serial/8250/8250_mtk.c
index 7a11fac77..78883ca64 100644
--- a/kernel/drivers/tty/serial/8250/8250_mtk.c
+++ b/kernel/drivers/tty/serial/8250/8250_mtk.c
@@ -34,6 +34,7 @@
struct mtk8250_data {
int line;
struct clk *uart_clk;
+ struct clk *bus_clk;
};
static void
@@ -115,6 +116,36 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios,
tty_termios_encode_baud_rate(termios, baud, baud);
}
+static int mtk8250_runtime_suspend(struct device *dev)
+{
+ struct mtk8250_data *data = dev_get_drvdata(dev);
+
+ clk_disable_unprepare(data->uart_clk);
+ clk_disable_unprepare(data->bus_clk);
+
+ return 0;
+}
+
+static int mtk8250_runtime_resume(struct device *dev)
+{
+ struct mtk8250_data *data = dev_get_drvdata(dev);
+ int err;
+
+ err = clk_prepare_enable(data->uart_clk);
+ if (err) {
+ dev_warn(dev, "Can't enable clock\n");
+ return err;
+ }
+
+ err = clk_prepare_enable(data->bus_clk);
+ if (err) {
+ dev_warn(dev, "Can't enable bus clock\n");
+ return err;
+ }
+
+ return 0;
+}
+
static void
mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
{
@@ -130,22 +161,24 @@ mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old)
static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p,
struct mtk8250_data *data)
{
- int err;
- struct device_node *np = pdev->dev.of_node;
-
- data->uart_clk = of_clk_get(np, 0);
+ data->uart_clk = devm_clk_get(&pdev->dev, "baud");
if (IS_ERR(data->uart_clk)) {
- dev_warn(&pdev->dev, "Can't get timer clock\n");
- return PTR_ERR(data->uart_clk);
+ /*
+ * For compatibility with older device trees try unnamed
+ * clk when no baud clk can be found.
+ */
+ data->uart_clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(data->uart_clk)) {
+ dev_warn(&pdev->dev, "Can't get uart clock\n");
+ return PTR_ERR(data->uart_clk);
+ }
+
+ return 0;
}
- err = clk_prepare_enable(data->uart_clk);
- if (err) {
- dev_warn(&pdev->dev, "Can't prepare clock\n");
- clk_put(data->uart_clk);
- return err;
- }
- p->uartclk = clk_get_rate(data->uart_clk);
+ data->bus_clk = devm_clk_get(&pdev->dev, "bus");
+ if (IS_ERR(data->bus_clk))
+ return PTR_ERR(data->bus_clk);
return 0;
}
@@ -190,19 +223,24 @@ static int mtk8250_probe(struct platform_device *pdev)
uart.port.regshift = 2;
uart.port.private_data = data;
uart.port.set_termios = mtk8250_set_termios;
+ uart.port.uartclk = clk_get_rate(data->uart_clk);
/* Disable Rate Fix function */
writel(0x0, uart.port.membase +
(MTK_UART_RATE_FIX << uart.port.regshift));
- data->line = serial8250_register_8250_port(&uart);
- if (data->line < 0)
- return data->line;
-
platform_set_drvdata(pdev, data);
- pm_runtime_set_active(&pdev->dev);
pm_runtime_enable(&pdev->dev);
+ if (!pm_runtime_enabled(&pdev->dev)) {
+ err = mtk8250_runtime_resume(&pdev->dev);
+ if (err)
+ return err;
+ }
+
+ data->line = serial8250_register_8250_port(&uart);
+ if (data->line < 0)
+ return data->line;
return 0;
}
@@ -214,13 +252,13 @@ static int mtk8250_remove(struct platform_device *pdev)
pm_runtime_get_sync(&pdev->dev);
serial8250_unregister_port(data->line);
- if (!IS_ERR(data->uart_clk)) {
- clk_disable_unprepare(data->uart_clk);
- clk_put(data->uart_clk);
- }
pm_runtime_disable(&pdev->dev);
pm_runtime_put_noidle(&pdev->dev);
+
+ if (!pm_runtime_status_suspended(&pdev->dev))
+ mtk8250_runtime_suspend(&pdev->dev);
+
return 0;
}
@@ -244,28 +282,6 @@ static int mtk8250_resume(struct device *dev)
}
#endif /* CONFIG_PM_SLEEP */
-#ifdef CONFIG_PM
-static int mtk8250_runtime_suspend(struct device *dev)
-{
- struct mtk8250_data *data = dev_get_drvdata(dev);
-
- if (!IS_ERR(data->uart_clk))
- clk_disable_unprepare(data->uart_clk);
-
- return 0;
-}
-
-static int mtk8250_runtime_resume(struct device *dev)
-{
- struct mtk8250_data *data = dev_get_drvdata(dev);
-
- if (!IS_ERR(data->uart_clk))
- clk_prepare_enable(data->uart_clk);
-
- return 0;
-}
-#endif
-
static const struct dev_pm_ops mtk8250_pm_ops = {
SET_SYSTEM_SLEEP_PM_OPS(mtk8250_suspend, mtk8250_resume)
SET_RUNTIME_PM_OPS(mtk8250_runtime_suspend, mtk8250_runtime_resume,
@@ -289,6 +305,21 @@ static struct platform_driver mtk8250_platform_driver = {
};
module_platform_driver(mtk8250_platform_driver);
+#ifdef CONFIG_SERIAL_8250_CONSOLE
+static int __init early_mtk8250_setup(struct earlycon_device *device,
+ const char *options)
+{
+ if (!device->port.membase)
+ return -ENODEV;
+
+ device->port.iotype = UPIO_MEM32;
+
+ return early_serial8250_setup(device, NULL);
+}
+
+OF_EARLYCON_DECLARE(mtk8250, "mediatek,mt6577-uart", early_mtk8250_setup);
+#endif
+
MODULE_AUTHOR("Matthias Brugger");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Mediatek 8250 serial port driver");