| Message ID | 989cf7bf-b7ea-0b41-510b-6eab403f0185@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
On 02/21/2017 12:26 PM, Heiner Kallweit wrote: > Add handling of RNG0 clock to the driver. > > Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> > --- > v2: > - consider that clock is optional > - use managed call to clk_disable_unprepare to ensure that > cleaning up is done in the right order if driver is removed > --- > drivers/char/hw_random/meson-rng.c | 22 ++++++++++++++++++++++ > 1 file changed, 22 insertions(+) > > diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c > index 119d6984..2e23be80 100644 > --- a/drivers/char/hw_random/meson-rng.c > +++ b/drivers/char/hw_random/meson-rng.c > @@ -62,6 +62,7 @@ > #include <linux/slab.h> > #include <linux/types.h> > #include <linux/of.h> > +#include <linux/clk.h> > > #define RNG_DATA 0x00 > > @@ -69,6 +70,7 @@ struct meson_rng_data { > void __iomem *base; > struct platform_device *pdev; > struct hwrng rng; > + struct clk *core_clk; > }; > > static int meson_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) > @@ -81,11 +83,17 @@ static int meson_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) > return sizeof(u32); > } > > +static void meson_rng_clk_disable(void *clk) > +{ > + clk_disable_unprepare(clk); > +} > + > static int meson_rng_probe(struct platform_device *pdev) > { > struct device *dev = &pdev->dev; > struct meson_rng_data *data; > struct resource *res; > + int ret; > > data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); > if (!data) > @@ -98,6 +106,20 @@ static int meson_rng_probe(struct platform_device *pdev) > if (IS_ERR(data->base)) > return PTR_ERR(data->base); > > + data->core_clk = devm_clk_get(dev, "core"); > + if (IS_ERR(data->core_clk)) > + data->core_clk = NULL; > + > + if (data->core_clk) { This "if" is useless, if core_clk is NULL, this will work also. > + ret = clk_prepare_enable(data->core_clk); > + if (ret) > + return ret; > + ret = devm_add_action_or_reset(dev, meson_rng_clk_disable, > + data->core_clk); > + if (ret) > + return ret; > + } > + > data->rng.name = pdev->name; > data->rng.read = meson_rng_read; > >
Am 21.02.2017 um 22:21 schrieb Neil Armstrong: > On 02/21/2017 12:26 PM, Heiner Kallweit wrote: >> Add handling of RNG0 clock to the driver. >> >> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> >> --- >> v2: >> - consider that clock is optional >> - use managed call to clk_disable_unprepare to ensure that >> cleaning up is done in the right order if driver is removed >> --- >> drivers/char/hw_random/meson-rng.c | 22 ++++++++++++++++++++++ >> 1 file changed, 22 insertions(+) >> >> diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c >> index 119d6984..2e23be80 100644 >> --- a/drivers/char/hw_random/meson-rng.c >> +++ b/drivers/char/hw_random/meson-rng.c >> @@ -62,6 +62,7 @@ >> #include <linux/slab.h> >> #include <linux/types.h> >> #include <linux/of.h> >> +#include <linux/clk.h> >> >> #define RNG_DATA 0x00 >> >> @@ -69,6 +70,7 @@ struct meson_rng_data { >> void __iomem *base; >> struct platform_device *pdev; >> struct hwrng rng; >> + struct clk *core_clk; >> }; >> >> static int meson_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) >> @@ -81,11 +83,17 @@ static int meson_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) >> return sizeof(u32); >> } >> >> +static void meson_rng_clk_disable(void *clk) >> +{ >> + clk_disable_unprepare(clk); >> +} >> + >> static int meson_rng_probe(struct platform_device *pdev) >> { >> struct device *dev = &pdev->dev; >> struct meson_rng_data *data; >> struct resource *res; >> + int ret; >> >> data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); >> if (!data) >> @@ -98,6 +106,20 @@ static int meson_rng_probe(struct platform_device *pdev) >> if (IS_ERR(data->base)) >> return PTR_ERR(data->base); >> >> + data->core_clk = devm_clk_get(dev, "core"); >> + if (IS_ERR(data->core_clk)) >> + data->core_clk = NULL; >> + >> + if (data->core_clk) { > > This "if" is useless, if core_clk is NULL, this will work also. > Regarding clk_prepare_enable you're right. However we need this "if" for the call to devm_add_action_or_reset because we can't provide a NULL pointer as data argument. And including clk_prepare_enable in the if clause creates no overhead and is clearer IMHO. >> + ret = clk_prepare_enable(data->core_clk); >> + if (ret) >> + return ret; >> + ret = devm_add_action_or_reset(dev, meson_rng_clk_disable, >> + data->core_clk); >> + if (ret) >> + return ret; >> + } >> + >> data->rng.name = pdev->name; >> data->rng.read = meson_rng_read; >> >> > >
diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c index 119d6984..2e23be80 100644 --- a/drivers/char/hw_random/meson-rng.c +++ b/drivers/char/hw_random/meson-rng.c @@ -62,6 +62,7 @@ #include <linux/slab.h> #include <linux/types.h> #include <linux/of.h> +#include <linux/clk.h> #define RNG_DATA 0x00 @@ -69,6 +70,7 @@ struct meson_rng_data { void __iomem *base; struct platform_device *pdev; struct hwrng rng; + struct clk *core_clk; }; static int meson_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) @@ -81,11 +83,17 @@ static int meson_rng_read(struct hwrng *rng, void *buf, size_t max, bool wait) return sizeof(u32); } +static void meson_rng_clk_disable(void *clk) +{ + clk_disable_unprepare(clk); +} + static int meson_rng_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct meson_rng_data *data; struct resource *res; + int ret; data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); if (!data) @@ -98,6 +106,20 @@ static int meson_rng_probe(struct platform_device *pdev) if (IS_ERR(data->base)) return PTR_ERR(data->base); + data->core_clk = devm_clk_get(dev, "core"); + if (IS_ERR(data->core_clk)) + data->core_clk = NULL; + + if (data->core_clk) { + ret = clk_prepare_enable(data->core_clk); + if (ret) + return ret; + ret = devm_add_action_or_reset(dev, meson_rng_clk_disable, + data->core_clk); + if (ret) + return ret; + } + data->rng.name = pdev->name; data->rng.read = meson_rng_read;
Add handling of RNG0 clock to the driver. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> --- v2: - consider that clock is optional - use managed call to clk_disable_unprepare to ensure that cleaning up is done in the right order if driver is removed --- drivers/char/hw_random/meson-rng.c | 22 ++++++++++++++++++++++ 1 file changed, 22 insertions(+)