| Message ID | 1430117397-13517-5-git-send-email-s.hauer@pengutronix.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
2015-04-27 8:49 GMT+02:00 Sascha Hauer <s.hauer@pengutronix.de>: > The mtk 8250 needs two clocks, one for providing the baudrate and > one that needs to be enabled for register accesses. The latter has > not been supported, this patch adds support for it. It is optional > for now since not all SoCs provide a bus clock. > > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> > --- > .../devicetree/bindings/serial/mtk-uart.txt | 12 ++++++++-- > 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 4415226..8d63f1d 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 2f28bd0..8eb3876 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; > }; Not sure if it would be better to rename the uart_clk to baud_clk which reflects the new naming scheme. > > 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); bus_clk can be NULL. > > 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; > + } > + Same here.
On Tue, May 05, 2015 at 05:41:16PM +0200, Matthias Brugger wrote: > 2015-04-27 8:49 GMT+02:00 Sascha Hauer <s.hauer@pengutronix.de>: > > The mtk 8250 needs two clocks, one for providing the baudrate and > > one that needs to be enabled for register accesses. The latter has > > not been supported, this patch adds support for it. It is optional > > for now since not all SoCs provide a bus clock. > > > > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> > > --- > > .../devicetree/bindings/serial/mtk-uart.txt | 12 ++++++++-- > > 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 4415226..8d63f1d 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 2f28bd0..8eb3876 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; > > }; > > Not sure if it would be better to rename the uart_clk to baud_clk > which reflects the new naming scheme. Can do. > > > > > 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); > > bus_clk can be NULL. The clk core handles NULL clks just fine. They are considered dummy clks. You can prepare/enable them, clk_get_rate of course returns nothing useful. Sascha
2015-05-05 17:50 GMT+02:00 Sascha Hauer <s.hauer@pengutronix.de>: > On Tue, May 05, 2015 at 05:41:16PM +0200, Matthias Brugger wrote: >> 2015-04-27 8:49 GMT+02:00 Sascha Hauer <s.hauer@pengutronix.de>: >> > The mtk 8250 needs two clocks, one for providing the baudrate and >> > one that needs to be enabled for register accesses. The latter has >> > not been supported, this patch adds support for it. It is optional >> > for now since not all SoCs provide a bus clock. >> > >> > Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> >> > --- >> > .../devicetree/bindings/serial/mtk-uart.txt | 12 ++++++++-- >> > 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 4415226..8d63f1d 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 2f28bd0..8eb3876 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; >> > }; >> >> Not sure if it would be better to rename the uart_clk to baud_clk >> which reflects the new naming scheme. > > Can do. If you do so you can add: Acked-by: Matthias Brugger <matthias.bgg@gmail.com> Thanks, Matthias
diff --git a/Documentation/devicetree/bindings/serial/mtk-uart.txt b/Documentation/devicetree/bindings/serial/mtk-uart.txt index 4415226..8d63f1d 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 2f28bd0..8eb3876 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 +
The mtk 8250 needs two clocks, one for providing the baudrate and one that needs to be enabled for register accesses. The latter has not been supported, this patch adds support for it. It is optional for now since not all SoCs provide a bus clock. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> --- .../devicetree/bindings/serial/mtk-uart.txt | 12 ++++++++-- drivers/tty/serial/8250/8250_mtk.c | 28 ++++++++++++++++++---- 2 files changed, 34 insertions(+), 6 deletions(-)