Hi Anson,
On Wed, Jan 10, 2018 at 05:10:22PM +0800, Anson Huang wrote:
> Add optional clock enable/disable support for the SNVS pwrkey,
> which is required for accessing SNVS block on some i.MX SoCs
> like i.MX7D.
>
> If SNVS clock is required, it needs to be passed from dtb file
> and SNVS pwrkey driver will enable it.
>
> Signed-off-by: Anson Huang <Anson.Huang@xxxxxxx>
> ---
> drivers/input/keyboard/snvs_pwrkey.c | 30 ++++++++++++++++++++++++++----
> 1 file changed, 26 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/input/keyboard/snvs_pwrkey.c b/drivers/input/keyboard/snvs_pwrkey.c
> index 53c768b..51642aa 100644
> --- a/drivers/input/keyboard/snvs_pwrkey.c
> +++ b/drivers/input/keyboard/snvs_pwrkey.c
> @@ -21,6 +21,7 @@
> #include <linux/module.h>
> #include <linux/of.h>
> #include <linux/of_address.h>
> +#include <linux/clk.h>
> #include <linux/platform_device.h>
> #include <linux/mfd/syscon.h>
> #include <linux/regmap.h>
> @@ -43,6 +44,7 @@ struct pwrkey_drv_data {
> int wakeup;
> struct timer_list check_timer;
> struct input_dev *input;
> + struct clk *clk;
> };
>
> static void imx_imx_snvs_check_for_events(struct timer_list *t)
> @@ -129,6 +131,18 @@ static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
> return -EINVAL;
> }
>
> + pdata->clk = devm_clk_get(&pdev->dev, NULL);
> + if (IS_ERR(pdata->clk)) {
> + pdata->clk = NULL;
This is not right, as you do not handle the deferrals properly, not
differentiate between missing clock and other fatal errors.
Also, it looks like we need something like devm_clk_get_optional() for
your use case. Have you looked into adding such API?
> + } else {
> + error = clk_prepare_enable(pdata->clk);
> + if (error) {
> + dev_err(&pdev->dev,
> + "Could not prepare or enable the snvs clock\n");
> + return error;
> + }
> + }
> +
> regmap_update_bits(pdata->snvs, SNVS_LPCR_REG, SNVS_LPCR_DEP_EN, SNVS_LPCR_DEP_EN);
>
> /* clear the unexpected interrupt before driver ready */
> @@ -139,7 +153,8 @@ static int imx_snvs_pwrkey_probe(struct platform_device *pdev)
> input = devm_input_allocate_device(&pdev->dev);
> if (!input) {
> dev_err(&pdev->dev, "failed to allocate the input device\n");
> - return -ENOMEM;
> + error = -ENOMEM;
> + goto error_snvs_pwrkey_device_register;
Instead of mixing automatic and manual resource release please install a
custom devm action disabling the clock. This will also ensure that we
disable the clock when unbinding device.
Thanks.
--
Dmitry
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