| Message ID | eff6bfbe-3257-5d74-35c7-226a29c61fcb@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
On 20 February 2017 at 02:05, Heiner Kallweit <hkallweit1@gmail.com> wrote: > Add handling of RNG0 clock to the driver. > > Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> > --- > drivers/char/hw_random/meson-rng.c | 27 ++++++++++++++++++++++++++- > 1 file changed, 26 insertions(+), 1 deletion(-) > > diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c > index 119d6984..1f586e48 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) > @@ -86,6 +88,7 @@ static int meson_rng_probe(struct platform_device *pdev) > struct device *dev = &pdev->dev; > struct meson_rng_data *data; > struct resource *res; > + int ret; Variable ret is not used. It can be removed. > data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); > if (!data) > @@ -98,12 +101,33 @@ 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)) > + return PTR_ERR(data->core_clk); > + > + ret = clk_prepare_enable(data->core_clk); > + if (ret) > + return ret; > + > data->rng.name = pdev->name; > data->rng.read = meson_rng_read; > > platform_set_drvdata(pdev, data); > > - return devm_hwrng_register(dev, &data->rng); > + ret = devm_hwrng_register(dev, &data->rng); > + if (ret) > + clk_disable_unprepare(data->core_clk); > + > + return ret; > +} > + > +static int meson_rng_remove(struct platform_device *pdev) > +{ > + struct meson_rng_data *data = platform_get_drvdata(pdev); > + > + clk_disable_unprepare(data->core_clk); > + > + return 0; > } In .remove clock gets disabled before the hwrng_unregister is called. The device node '/dev/hwrng' could be accessed while meson_rng_remove is called which could lead to problems. Instead of devm_hwrng_register use hwrng_register in .probe and call hwrng_unregister in .remove. > static const struct of_device_id meson_rng_of_match[] = { > @@ -114,6 +138,7 @@ MODULE_DEVICE_TABLE(of, meson_rng_of_match); > > static struct platform_driver meson_rng_driver = { > .probe = meson_rng_probe, > + .remove = meson_rng_remove, > .driver = { > .name = "meson-rng", > .of_match_table = meson_rng_of_match, > -- > 2.11.1 > >
diff --git a/drivers/char/hw_random/meson-rng.c b/drivers/char/hw_random/meson-rng.c index 119d6984..1f586e48 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) @@ -86,6 +88,7 @@ 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) @@ -98,12 +101,33 @@ 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)) + return PTR_ERR(data->core_clk); + + ret = clk_prepare_enable(data->core_clk); + if (ret) + return ret; + data->rng.name = pdev->name; data->rng.read = meson_rng_read; platform_set_drvdata(pdev, data); - return devm_hwrng_register(dev, &data->rng); + ret = devm_hwrng_register(dev, &data->rng); + if (ret) + clk_disable_unprepare(data->core_clk); + + return ret; +} + +static int meson_rng_remove(struct platform_device *pdev) +{ + struct meson_rng_data *data = platform_get_drvdata(pdev); + + clk_disable_unprepare(data->core_clk); + + return 0; } static const struct of_device_id meson_rng_of_match[] = { @@ -114,6 +138,7 @@ MODULE_DEVICE_TABLE(of, meson_rng_of_match); static struct platform_driver meson_rng_driver = { .probe = meson_rng_probe, + .remove = meson_rng_remove, .driver = { .name = "meson-rng", .of_match_table = meson_rng_of_match,
Add handling of RNG0 clock to the driver. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> --- drivers/char/hw_random/meson-rng.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-)