linux-kernel - Re: [RESEND PATCH v5 2/2] i2c: muxes: pca954x: Enable features on MAX7357

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Message-ID: <CABqG17gj+NFQUrXByp07YMMh0aAhV7=szXuQfATu4DtRoB9BRA@mail.gmail.com>
Date:   Mon, 20 Nov 2023 15:43:50 +0530
From:   Naresh Solanki <naresh.solanki@...ements.com>
To:     Peter Rosin <peda@...ntia.se>
Cc:     andi.shyti@...nel.org, robh@...nel.org,
        Patrick Rudolph <patrick.rudolph@...ements.com>,
        linux-i2c@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [RESEND PATCH v5 2/2] i2c: muxes: pca954x: Enable features on MAX7357

Hi

I wanted to confirm whether there are any additional details or
modifications needed on my end to expedite the review
process.
I am more than willing to address any concerns or make
necessary adjustments to ensure that the patch is aligned

Regards,
Naresh

On Thu, 9 Nov 2023 at 14:53, Naresh Solanki
<naresh.solanki@...ements.com> wrote:
>
> From: Patrick Rudolph <patrick.rudolph@...ements.com>
>
> Enable additional features based on DT settings and unconditionally
> release the shared interrupt pin after 1.6 seconds and allow to use
> it as reset.
>
> These features aren't enabled by default and it's up to board designer
> to validate for proper functioning and detection of devices in secondary
> bus as sometimes it can cause secondary bus being disabled.
>
> Signed-off-by: Patrick Rudolph <patrick.rudolph@...ements.com>
> Signed-off-by: Naresh Solanki <naresh.solanki@...ements.com>
>
> ---
> Changes in V5:
> - Fix typos
> - Update comment
> - Add newline in dev_warn
> Changes in V4:
> - Drop max7358
> - Update #define
> - Move conf variable
> - Print warning when I2C_FUNC_SMBUS_WRITE_BYTE_DATA isn't supported
> Changes in V3:
> - Delete unused #define
> - Update pca954x_init
> - Update commit message
> Changes in V2:
> - Update comments
> - Update check for DT properties
> ---
>  drivers/i2c/muxes/i2c-mux-pca954x.c | 43 ++++++++++++++++++++++++++++-
>  1 file changed, 42 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/i2c/muxes/i2c-mux-pca954x.c b/drivers/i2c/muxes/i2c-mux-pca954x.c
> index 2219062104fb..f5dfc33b97c0 100644
> --- a/drivers/i2c/muxes/i2c-mux-pca954x.c
> +++ b/drivers/i2c/muxes/i2c-mux-pca954x.c
> @@ -57,6 +57,20 @@
>
>  #define PCA954X_IRQ_OFFSET 4
>
> +/*
> + * MAX7357's configuration register is writeable after POR, but
> + * can be locked by setting the basic mode bit. MAX7358 configuration
> + * register is locked by default and needs to be unlocked first.
> + * The configuration register holds the following settings:
> + */
> +#define MAX7357_CONF_INT_ENABLE                        BIT(0)
> +#define MAX7357_CONF_FLUSH_OUT                 BIT(1)
> +#define MAX7357_CONF_RELEASE_INT               BIT(2)
> +#define MAX7357_CONF_DISCON_SINGLE_CHAN                BIT(4)
> +#define MAX7357_CONF_PRECONNECT_TEST           BIT(7)
> +
> +#define MAX7357_POR_DEFAULT_CONF               MAX7357_CONF_INT_ENABLE
> +
>  enum pca_type {
>         max_7356,
>         max_7357,
> @@ -470,7 +484,34 @@ static int pca954x_init(struct i2c_client *client, struct pca954x *data)
>         else
>                 data->last_chan = 0; /* Disconnect multiplexer */
>
> -       ret = i2c_smbus_write_byte(client, data->last_chan);
> +       if (device_is_compatible(&client->dev, "maxim,max7357")) {
> +               if (i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
> +                       u8 conf = MAX7357_POR_DEFAULT_CONF;
> +                       /*
> +                        * The interrupt signal is shared with the reset pin. Release the
> +                        * interrupt after 1.6 seconds to allow using the pin as reset.
> +                        */
> +                       conf |= MAX7357_CONF_RELEASE_INT;
> +
> +                       if (device_property_read_bool(&client->dev, "maxim,isolate-stuck-channel"))
> +                               conf |= MAX7357_CONF_DISCON_SINGLE_CHAN;
> +                       if (device_property_read_bool(&client->dev,
> +                                                     "maxim,send-flush-out-sequence"))
> +                               conf |= MAX7357_CONF_FLUSH_OUT;
> +                       if (device_property_read_bool(&client->dev,
> +                                                     "maxim,preconnection-wiggle-test-enable"))
> +                               conf |= MAX7357_CONF_PRECONNECT_TEST;
> +
> +                       ret = i2c_smbus_write_byte_data(client, data->last_chan, conf);
> +               } else {
> +                       dev_warn(&client->dev, "Write byte data not supported."
> +                                "Cannot enable enhanced mode features\n");
> +                       ret = i2c_smbus_write_byte(client, data->last_chan);
> +               }
> +       } else {
> +               ret = i2c_smbus_write_byte(client, data->last_chan);
> +       }
> +
>         if (ret < 0)
>                 data->last_chan = 0;
>
> --
> 2.41.0
>