On Mon, Jun 17, 2024 at 11:26 PM Anand Moon <linux.amoon@xxxxxxxxx> wrote: > > Hi Sam, > > On Tue, 18 Jun 2024 at 06:08, Sam Protsenko <semen.protsenko@xxxxxxxxxx> wrote: > > > > Some SoCs like Exynos850 might require the SSS bus clock (PCLK) to be > > enabled in order to access TRNG registers. Add and handle optional PCLK > > clock accordingly to make it possible. > > > > Signed-off-by: Sam Protsenko <semen.protsenko@xxxxxxxxxx> > > --- > > drivers/char/hw_random/exynos-trng.c | 22 ++++++++++++++++++++-- > > 1 file changed, 20 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/char/hw_random/exynos-trng.c b/drivers/char/hw_random/exynos-trng.c > > index 88a5088ed34d..4520a280134c 100644 > > --- a/drivers/char/hw_random/exynos-trng.c > > +++ b/drivers/char/hw_random/exynos-trng.c > > @@ -47,7 +47,8 @@ > > struct exynos_trng_dev { > > struct device *dev; > > void __iomem *mem; > > - struct clk *clk; > > + struct clk *clk; /* operating clock */ > > + struct clk *pclk; /* bus clock */ > > struct hwrng rng; > > }; > > > > @@ -141,10 +142,23 @@ static int exynos_trng_probe(struct platform_device *pdev) > > goto err_clock; > > } > > > > + trng->pclk = devm_clk_get_optional(&pdev->dev, "pclk"); > > Use devm_clk_get_optional_enabled to avoid clk_prepare_enable > Thanks for pointing that out! Will fix in v2. > > + if (IS_ERR(trng->pclk)) { > > + ret = dev_err_probe(&pdev->dev, PTR_ERR(trng->pclk), > > + "cannot get pclk"); > > + goto err_clock; > > + } > > + > > + ret = clk_prepare_enable(trng->pclk); > > + if (ret) { > > + dev_err(&pdev->dev, "Could not enable the pclk.\n"); > > + goto err_clock; > > + } > > + > > ret = clk_prepare_enable(trng->clk); > > Use devm_clk_get_enabled for this clock > > > if (ret) { > > dev_err(&pdev->dev, "Could not enable the clk.\n"); > > - goto err_clock; > > + goto err_clock_enable; > > } > > > > ret = devm_hwrng_register(&pdev->dev, &trng->rng); > > @@ -160,6 +174,9 @@ static int exynos_trng_probe(struct platform_device *pdev) > > err_register: > > clk_disable_unprepare(trng->clk); > > > > +err_clock_enable: > > + clk_disable_unprepare(trng->pclk); > > + > > err_clock: > > pm_runtime_put_noidle(&pdev->dev); > > > > @@ -174,6 +191,7 @@ static void exynos_trng_remove(struct platform_device *pdev) > > struct exynos_trng_dev *trng = platform_get_drvdata(pdev); > > > > clk_disable_unprepare(trng->clk); > > + clk_disable_unprepare(trng->pclk); > > > > pm_runtime_put_sync(&pdev->dev); > > pm_runtime_disable(&pdev->dev); > > -- > > 2.39.2 > > > > > > Thanks > -Anand