diff options
| -rw-r--r-- | Documentation/devicetree/bindings/serial/mtk-uart.txt | 12 | ||||
| -rw-r--r-- | drivers/tty/serial/8250/8250_mtk.c | 28 |
2 files changed, 34 insertions, 6 deletions
diff --git a/Documentation/devicetree/bindings/serial/mtk-uart.txt b/Documentation/devicetree/bindings/serial/mtk-uart.txt index 44152261e5c5..8d63f1da07aa 100644 --- a/Documentation/devicetree/bindings/serial/mtk-uart.txt +++ b/Documentation/devicetree/bindings/serial/mtk-uart.txt @@ -14,7 +14,14 @@ Required properties: - interrupts: A single interrupt specifier. -- clocks: Clock driving the hardware. +- clocks : Must contain an entry for each entry in clock-names. + See ../clocks/clock-bindings.txt for details. +- clock-names: + - "baud": The clock the baudrate is derived from + - "bus": The bus clock for register accesses (optional) + +For compatibility with older device trees an unnamed clock is used for the +baud clock if the baudclk does not exist. Do not use this for new designs. Example: @@ -22,5 +29,6 @@ Example: compatible = "mediatek,mt6589-uart", "mediatek,mt6577-uart"; reg = <0x11006000 0x400>; interrupts = <GIC_SPI 51 IRQ_TYPE_LEVEL_LOW>; - clocks = <&uart_clk>; + clocks = <&uart_clk>, <&bus_clk>; + clock-names = "baud", "bus"; }; diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c index 2f28bd08b69f..8eb3876563f1 100644 --- a/drivers/tty/serial/8250/8250_mtk.c +++ b/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 @@ -120,6 +121,7 @@ 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; } @@ -135,6 +137,12 @@ static int mtk8250_runtime_resume(struct device *dev) return err; } + err = clk_prepare_enable(data->bus_clk); + if (err) { + dev_warn(dev, "Can't enable bus clock\n"); + return err; + } + return 0; } @@ -153,13 +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) { - data->uart_clk = devm_clk_get(&pdev->dev, NULL); + data->uart_clk = devm_clk_get(&pdev->dev, "baud"); if (IS_ERR(data->uart_clk)) { - dev_warn(&pdev->dev, "Can't get uart 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; } - 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; } @@ -204,6 +223,7 @@ 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 + |