Re: [PATCH v2 23/91] reset: simple: Add reset callback

From: Philipp Zabel
Date: Wed May 06 2020 - 05:26:54 EST


Hi Maxime,

On Fri, 2020-04-24 at 17:34 +0200, Maxime Ripard wrote:
> The reset-simple code lacks a reset callback that is still pretty easy to
> implement. The only real thing to consider is the delay needed for a device
> to be reset, so let's expose that as part of the reset-simple driver data.
>
> Cc: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>
> Signed-off-by: Maxime Ripard <maxime@xxxxxxxxxx>
> ---
> drivers/reset/reset-simple.c | 24 ++++++++++++++++++++++++
> include/linux/reset/reset-simple.h | 6 ++++++
> 2 files changed, 30 insertions(+)
>
> diff --git a/drivers/reset/reset-simple.c b/drivers/reset/reset-simple.c
> index c854aa351640..602ed972b0a9 100644
> --- a/drivers/reset/reset-simple.c
> +++ b/drivers/reset/reset-simple.c
> @@ -11,6 +11,7 @@
> * Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx>
> */
>
> +#include <linux/delay.h>
> #include <linux/device.h>
> #include <linux/err.h>
> #include <linux/io.h>
> @@ -63,6 +64,28 @@ static int reset_simple_deassert(struct reset_controller_dev *rcdev,
> return reset_simple_update(rcdev, id, false);
> }
>
> +static int reset_simple_reset(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + struct reset_simple_data *data = to_reset_simple_data(rcdev);
> + int ret;
> +
> + if (!data->reset_us)
> + return -ENOTSUPP;
> +
> + ret = reset_simple_assert(rcdev, id);
> + if (ret)
> + return ret;
> +
> + usleep_range(data->reset_us, data->reset_us * 2);
> +
> + ret = reset_simple_deassert(rcdev, id);
> + if (ret)
> + return ret;
> +
> + return 0;

Just
return reset_simple_deassert(rcdev, id);
here.

> +}
> +
> static int reset_simple_status(struct reset_controller_dev *rcdev,
> unsigned long id)
> {
> @@ -80,6 +103,7 @@ static int reset_simple_status(struct reset_controller_dev *rcdev,
> const struct reset_control_ops reset_simple_ops = {
> .assert = reset_simple_assert,
> .deassert = reset_simple_deassert,
> + .reset = reset_simple_reset,
> .status = reset_simple_status,
> };
> EXPORT_SYMBOL_GPL(reset_simple_ops);
> diff --git a/include/linux/reset/reset-simple.h b/include/linux/reset/reset-simple.h
> index 08ccb25a55e6..5eb83625a495 100644
> --- a/include/linux/reset/reset-simple.h
> +++ b/include/linux/reset/reset-simple.h
> @@ -27,6 +27,11 @@
> * @status_active_low: if true, bits read back as cleared while the reset is
> * asserted. Otherwise, bits read back as set while the
> * reset is asserted.
> + * @reset_us: Minimum delay in microseconds needed that needs to be
> + * waited for between an assert and a deassert to reset the
> + * device. If multiple consumers with different delay
> + * requirements are connected to this controller, it must
> + * be the largest minimum delay.

Please mention that 0 does not meen 0 Âs delay, but unknown and thus
reset callback not supported.

With these two issues fixed
Reviewed-by: Philipp Zabel <p.zabel@xxxxxxxxxxxxxx>

regards
Philipp