[PATCH v2 1/1] clk: clk-gpio: add actual gated clock

[Sean Anderson]

On 12/16/23 19:19, Marek Vasut wrote:
> On 12/16/23 17:56, Sean Anderson wrote:
>> On 12/16/23 11:52, Marek Vasut wrote:
>>> On 12/16/23 16:37, Sean Anderson wrote:
>>>> On 12/16/23 03:48, Svyatoslav Ryhel wrote:
>>>>> Existing gpio-gate-clock driver acts like a simple GPIO switch without any
>>>>> effect on gated clock. Add actual clock actions into enable/disable ops and
>>>>> implement get_rate op by passing gated clock if it is enabled.
>>>>>
>>>>> Signed-off-by: Svyatoslav Ryhel <clamor95 at gmail.com>
>>>>> ---
>>>>>   drivers/clk/clk-gpio.c | 44 ++++++++++++++++++++++++++++++++++--------
>>>>>   1 file changed, 36 insertions(+), 8 deletions(-)
>>>>>
>>>>> diff --git a/drivers/clk/clk-gpio.c b/drivers/clk/clk-gpio.c
>>>>> index 26d795b978..72d9747a47 100644
>>>>> --- a/drivers/clk/clk-gpio.c
>>>>> +++ b/drivers/clk/clk-gpio.c
>>>>> @@ -3,19 +3,23 @@
>>>>>    * Copyright (C) 2023 Marek Vasut <marek.vasut+renesas at mailbox.org>
>>>>>    */
>>>>> -#include <asm/gpio.h>
>>>>> -#include <common.h>
>>>>> -#include <clk-uclass.h>
>>>>> +#include <clk.h>
>>>>>   #include <dm.h>
>>>>> +#include <clk-uclass.h>
>>>>> +#include <linux/clk-provider.h>
>>>>> +
>>>>> +#include <asm/gpio.h>
>>>>>   struct clk_gpio_priv {
>>>>> -    struct gpio_desc    enable;
>>>>> +    struct gpio_desc    enable;    /* GPIO, controlling the gate */
>>>>> +    struct clk        *clk;    /* Gated clock */
>>>>>   };
>>>>>   static int clk_gpio_enable(struct clk *clk)
>>>>>   {
>>>>>       struct clk_gpio_priv *priv = dev_get_priv(clk->dev);
>>>>> +    clk_enable(priv->clk);
>>>>>       dm_gpio_set_value(&priv->enable, 1);
>>>>>       return 0;
>>>>> @@ -26,21 +30,45 @@ static int clk_gpio_disable(struct clk *clk)
>>>>>       struct clk_gpio_priv *priv = dev_get_priv(clk->dev);
>>>>>       dm_gpio_set_value(&priv->enable, 0);
>>>>> +    clk_disable(priv->clk);
>>>>>       return 0;
>>>>>   }
>>>>> +static ulong clk_gpio_get_rate(struct clk *clk)
>>>>> +{
>>>>> +    struct clk_gpio_priv *priv = dev_get_priv(clk->dev);
>>>>> +
>>>>> +    return clk_get_rate(priv->clk);
>>>>> +}
>>>>> +
>>>>>   const struct clk_ops clk_gpio_ops = {
>>>>>       .enable        = clk_gpio_enable,
>>>>>       .disable    = clk_gpio_disable,
>>>>> +    .get_rate    = clk_gpio_get_rate,
>>>>>   };
>>>>> -static int clk_gpio_probe(struct udevice *dev)
>>>>> +static int clk_gpio_of_to_plat(struct udevice *dev)
>>>>>   {
>>>>>       struct clk_gpio_priv *priv = dev_get_priv(dev);
>>>>> +    int ret;
>>>>> -    return gpio_request_by_name(dev, "enable-gpios", 0,
>>>>> -                    &priv->enable, GPIOD_IS_OUT);
>>>>> +    priv->clk = devm_clk_get(dev, NULL);
>>>>> +    if (IS_ERR(priv->clk)) {
>>>>> +        log_debug("%s: Could not get gated clock: %ld\n",
>>>>> +              __func__, PTR_ERR(priv->clk));
>>>>> +        return PTR_ERR(priv->clk);
>>>>> +    }
>>>>> +
>>>>> +    ret = gpio_request_by_name(dev, "enable-gpios", 0,
>>>>> +                   &priv->enable, GPIOD_IS_OUT);
>>>>> +    if (ret) {
>>>>> +        log_debug("%s: Could not decode enable-gpios (%d)\n",
>>>>> +              __func__, ret);
>>>>> +        return ret;
>>>>> +    }
>>>>> +
>>>>> +    return 0;
>>>
>>> All this forwarding of clock enable/disable/get_rate for parent clock should already be done in clock core. If it is not, then it should be fixed in clock core.
>>
>> Only CCF forwards things. It's up to the driver to do it in the non-CCF case.
> 
> Shall we add dependency on CCF instead of duplicating code in drivers ?

I'd rather not. This will be useful on non-CCF systems.

--Sean