| Message ID | 1471545645-11437-1-git-send-email-linus.walleij@linaro.org |
|---|---|
| State | Accepted |
| Commit | 3526403353c2a1b94c3181f900582626d23c339b |
| Headers | show |
On Thu, 18 Aug 2016, Linus Walleij wrote: > The MSM8660, APQ8060, IPQ806x and MSM8960 have a GCC clock > to the message RAM used by the RPM. This needs to be enabled > for messages to pass through. This is a crude solution that > simply prepare/enable at probe() and disable/unprepare > at remove(). More elaborate PM is probably possible to > add later. > > The construction uses IS_ERR() to gracefully handle the > platforms that do not provide a message RAM clock. It will > bail out of probe only if the clock is hitting a probe > deferral situation. > > Of course this requires the proper device tree set-up: > > rpm: rpm@104000 { > compatible = "qcom,rpm-msm8660"; > clocks = <&gcc RPM_MSG_RAM_H_CLK>; > clock-names = "ram"; > ... > }; > > I have provided this in the MSM8660 device tree, and will > provide patches for the other targets. > > Cc: Björn Andersson <bjorn.andersson@linaro.org> > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> > --- > ChangeLog v1->v2: > - Exploit that a clk can be NULL and handled transparently > by the clock framework, simplifying the code > - Move clock disablement after the OF depopulation call > --- > drivers/mfd/qcom_rpm.c | 20 ++++++++++++++++++++ > 1 file changed, 20 insertions(+) Applied, thanks. > diff --git a/drivers/mfd/qcom_rpm.c b/drivers/mfd/qcom_rpm.c > index 2e44323455dd..315da71bde49 100644 > --- a/drivers/mfd/qcom_rpm.c > +++ b/drivers/mfd/qcom_rpm.c > @@ -21,6 +21,7 @@ > #include <linux/mfd/qcom_rpm.h> > #include <linux/mfd/syscon.h> > #include <linux/regmap.h> > +#include <linux/clk.h> > > #include <dt-bindings/mfd/qcom-rpm.h> > > @@ -48,6 +49,7 @@ struct qcom_rpm { > struct regmap *ipc_regmap; > unsigned ipc_offset; > unsigned ipc_bit; > + struct clk *ramclk; > > struct completion ack; > struct mutex lock; > @@ -501,6 +503,20 @@ static int qcom_rpm_probe(struct platform_device *pdev) > mutex_init(&rpm->lock); > init_completion(&rpm->ack); > > + /* Enable message RAM clock */ > + rpm->ramclk = devm_clk_get(&pdev->dev, "ram"); > + if (IS_ERR(rpm->ramclk)) { > + ret = PTR_ERR(rpm->ramclk); > + if (ret == -EPROBE_DEFER) > + return ret; > + /* > + * Fall through in all other cases, as the clock is > + * optional. (Does not exist on all platforms.) > + */ > + rpm->ramclk = NULL; > + } > + clk_prepare_enable(rpm->ramclk); /* Accepts NULL */ > + > irq_ack = platform_get_irq_byname(pdev, "ack"); > if (irq_ack < 0) { > dev_err(&pdev->dev, "required ack interrupt missing\n"); > @@ -620,7 +636,11 @@ static int qcom_rpm_probe(struct platform_device *pdev) > > static int qcom_rpm_remove(struct platform_device *pdev) > { > + struct qcom_rpm *rpm = dev_get_drvdata(&pdev->dev); > + > of_platform_depopulate(&pdev->dev); > + clk_disable_unprepare(rpm->ramclk); > + > return 0; > } > -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog
diff --git a/drivers/mfd/qcom_rpm.c b/drivers/mfd/qcom_rpm.c index 2e44323455dd..315da71bde49 100644 --- a/drivers/mfd/qcom_rpm.c +++ b/drivers/mfd/qcom_rpm.c @@ -21,6 +21,7 @@ #include <linux/mfd/qcom_rpm.h> #include <linux/mfd/syscon.h> #include <linux/regmap.h> +#include <linux/clk.h> #include <dt-bindings/mfd/qcom-rpm.h> @@ -48,6 +49,7 @@ struct qcom_rpm { struct regmap *ipc_regmap; unsigned ipc_offset; unsigned ipc_bit; + struct clk *ramclk; struct completion ack; struct mutex lock; @@ -501,6 +503,20 @@ static int qcom_rpm_probe(struct platform_device *pdev) mutex_init(&rpm->lock); init_completion(&rpm->ack); + /* Enable message RAM clock */ + rpm->ramclk = devm_clk_get(&pdev->dev, "ram"); + if (IS_ERR(rpm->ramclk)) { + ret = PTR_ERR(rpm->ramclk); + if (ret == -EPROBE_DEFER) + return ret; + /* + * Fall through in all other cases, as the clock is + * optional. (Does not exist on all platforms.) + */ + rpm->ramclk = NULL; + } + clk_prepare_enable(rpm->ramclk); /* Accepts NULL */ + irq_ack = platform_get_irq_byname(pdev, "ack"); if (irq_ack < 0) { dev_err(&pdev->dev, "required ack interrupt missing\n"); @@ -620,7 +636,11 @@ static int qcom_rpm_probe(struct platform_device *pdev) static int qcom_rpm_remove(struct platform_device *pdev) { + struct qcom_rpm *rpm = dev_get_drvdata(&pdev->dev); + of_platform_depopulate(&pdev->dev); + clk_disable_unprepare(rpm->ramclk); + return 0; }
The MSM8660, APQ8060, IPQ806x and MSM8960 have a GCC clock to the message RAM used by the RPM. This needs to be enabled for messages to pass through. This is a crude solution that simply prepare/enable at probe() and disable/unprepare at remove(). More elaborate PM is probably possible to add later. The construction uses IS_ERR() to gracefully handle the platforms that do not provide a message RAM clock. It will bail out of probe only if the clock is hitting a probe deferral situation. Of course this requires the proper device tree set-up: rpm: rpm@104000 { compatible = "qcom,rpm-msm8660"; clocks = <&gcc RPM_MSG_RAM_H_CLK>; clock-names = "ram"; ... }; I have provided this in the MSM8660 device tree, and will provide patches for the other targets. Cc: Björn Andersson <bjorn.andersson@linaro.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- ChangeLog v1->v2: - Exploit that a clk can be NULL and handled transparently by the clock framework, simplifying the code - Move clock disablement after the OF depopulation call --- drivers/mfd/qcom_rpm.c | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) -- 2.7.4