On Wed 05 Jun 2024 at 15:12, George Stark <gnstark@xxxxxxxxxxxxxxxxx> wrote:
> Hello Kelvin, Junyi
>
> On 6/5/24 05:44, Kelvin Zhang via B4 Relay wrote:
>> From: Junyi Zhao <junyi.zhao@xxxxxxxxxxx>
>> Add support for Amlogic S4 PWM.
>> Signed-off-by: Junyi Zhao <junyi.zhao@xxxxxxxxxxx>
>> Signed-off-by: Kelvin Zhang <kelvin.zhang@xxxxxxxxxxx>
>> ---
>> drivers/pwm/pwm-meson.c | 36 ++++++++++++++++++++++++++++++++++++
>> 1 file changed, 36 insertions(+)
>> diff --git a/drivers/pwm/pwm-meson.c b/drivers/pwm/pwm-meson.c
>> index b2f97dfb01bb..4f01847525b2 100644
>> --- a/drivers/pwm/pwm-meson.c
>> +++ b/drivers/pwm/pwm-meson.c
>> @@ -460,6 +460,34 @@ static int meson_pwm_init_channels_meson8b_v2(struct pwm_chip *chip)
>> return meson_pwm_init_clocks_meson8b(chip, mux_parent_data);
>> }
>> +static void meson_pwm_s4_put_clk(void *data)
>> +{
>> + struct clk *clk = data;
>> +
>> + clk_put(clk);
>> +}
>> +
>> +static int meson_pwm_init_channels_s4(struct pwm_chip *chip)
>> +{
>> + struct device *dev = pwmchip_parent(chip);
>> + struct device_node *np = dev->of_node;
>> + struct meson_pwm *meson = to_meson_pwm(chip);
>> + int i, ret;
>> +
>> + for (i = 0; i < MESON_NUM_PWMS; i++) {
>> + meson->channels[i].clk = of_clk_get(np, i);
>> + if (IS_ERR(meson->channels[i].clk)) {
>> + ret = PTR_ERR(meson->channels[i].clk);
>> + dev_err_probe(dev, ret, "Failed to get clk\n");
>> + return ret;
>> + }
>> + devm_add_action_or_reset(dev, meson_pwm_s4_put_clk,
>> + meson->channels[i].clk);
>
> devm_add_action_or_reset() result should be checked
>
>> + }
>> +
>> + return 0;
>> +}
>
> You can rewrite it a bit to always have a single allocation for devm node:
>
> static void meson_pwm_s4_put_clk(void *data)
> {
> struct meson_pwm *meson = data;
> int i;
>
> for (i = 0; i < MESON_NUM_PWMS; i++)
> clk_put(meson->channels[i].clk);
> }
This has already been discussed on v6.
This make the code un-necessarily complex and potentially put clock that
have not even been claimed.
>
> static int meson_pwm_init_channels_s4(struct pwm_chip *chip)
> {
> struct device *dev = pwmchip_parent(chip);
> struct device_node *np = dev->of_node;
> struct meson_pwm *meson = to_meson_pwm(chip);
> int i, ret;
>
> ret = devm_add_action(dev, meson_pwm_s4_put_clk, meson);
> if (ret)
> return ret;
>
> for (i = 0; i < MESON_NUM_PWMS; i++) {
> meson->channels[i].clk = of_clk_get(np, i);
> if (IS_ERR(meson->channels[i].clk)) {
> ret = PTR_ERR(meson->channels[i].clk);
> dev_err_probe(dev, ret, "Failed to get clk\n");
> return ret;
> }
> }
>
> return 0;
> }
--
Jerome
