Re: [PATCH v2 4/8] drm: mipi: add mipi_dsi_generic_write_multi_type()

[Caleb Connolly <caleb@xxxxxxxxxxxxxxxx>]

Hi Jessica,

On 12/07/2024 23:39, Jessica Zhang wrote:
> On 6/30/2024 11:36 AM, Caleb Connolly wrote:
> > Some panels like the Samsung AMB655X use long write commands for all
> > non-standard messages and do not work when trying to use the appropriate
> > command type.
> >
> > Support these panels by introducing a new helper to send commands of a
> > specific type, overriding the normal rules.
> >
> > Signed-off-by: Caleb Connolly <caleb@xxxxxxxxxxxxxxxx>
> > ---
> >   drivers/gpu/drm/drm_mipi_dsi.c | 40 
> > ++++++++++++++++++++++++++++++++++++++++
> >   include/drm/drm_mipi_dsi.h     | 16 ++++++++++++++++
> >   2 files changed, 56 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/drm_mipi_dsi.c 
> > b/drivers/gpu/drm/drm_mipi_dsi.c
> > index a471c46f5ca6..f2c7f3f23a6e 100644
> > --- a/drivers/gpu/drm/drm_mipi_dsi.c
> > +++ b/drivers/gpu/drm/drm_mipi_dsi.c
> > @@ -819,8 +819,48 @@ void mipi_dsi_generic_write_multi(struct 
> > mipi_dsi_multi_context *ctx,
> >       }
> >   }
> >   EXPORT_SYMBOL(mipi_dsi_generic_write_multi);
> > +/**
> > + * mipi_dsi_generic_write_raw_multi() - transmit data using a generic 
> > write packet of
> > + * a specific type
> > + * @ctx: Context for multiple DSI transactions
> > + * @type: data type of the packet
> > + * @payload: buffer containing the payload
> > + * @size: size of payload buffer
> > + *
> > + * This function will automatically choose the right data type 
> > depending on
> > + * the payload length.
>
> Hi Caleb,
>
> I'm a bit confused by the wording here. By "automatically", do you mean 
> the chosen by the macro calling this function?

Hmm, nope, looks like i either got this description totally wrong or 
copied it from somewhere and forgot to change it. I'll fix this in the 
next revision.

Kind regards,
> Thanks,
>
> Jessica Zhang
>
> > + *
> > + * Return: The number of bytes transmitted on success or a negative 
> > error code
> > + * on failure.
> > + */
> > +ssize_t mipi_dsi_generic_write_raw_multi(struct 
> > mipi_dsi_multi_context *ctx,
> > +                      u8 type, const void *payload, size_t size)
> > +{
> > +    struct mipi_dsi_device *dsi = ctx->dsi;
> > +    struct mipi_dsi_msg msg = {
> > +        .channel = dsi->channel,
> > +        .tx_buf = payload,
> > +        .tx_len = size,
> > +        .type = type,
> > +    };
> > +    ssize_t ret;
> > +
> > +    if (ctx->accum_err)
> > +        return 0;
> > +
> > +    ret = mipi_dsi_device_transfer(dsi, &msg);
> > +    if (ret < 0) {
> > +        ctx->accum_err = ret;
> > +        dev_err(&dsi->dev, "sending generic data %*ph failed: %zd\n",
> > +            (int)size, payload, ret);
> > +    }
> > +
> > +    return ret;
> > +}
> > +EXPORT_SYMBOL(mipi_dsi_generic_write_raw_multi);
> > +
> >   /**
> >    * mipi_dsi_generic_read() - receive data using a generic read packet
> >    * @dsi: DSI peripheral device
> >    * @params: buffer containing the request parameters
> > diff --git a/include/drm/drm_mipi_dsi.h b/include/drm/drm_mipi_dsi.h
> > index 71d121aeef24..fb23f4e3b94e 100644
> > --- a/include/drm/drm_mipi_dsi.h
> > +++ b/include/drm/drm_mipi_dsi.h
> > @@ -287,8 +287,10 @@ ssize_t mipi_dsi_generic_write(struct 
> > mipi_dsi_device *dsi, const void *payload,
> >   int mipi_dsi_generic_write_chatty(struct mipi_dsi_device *dsi,
> >                     const void *payload, size_t size);
> >   void mipi_dsi_generic_write_multi(struct mipi_dsi_multi_context *ctx,
> >                     const void *payload, size_t size);
> > +ssize_t mipi_dsi_generic_write_raw_multi(struct 
> > mipi_dsi_multi_context *ctx, u8 type,
> > +                    const void *payload, size_t size);
> >   ssize_t mipi_dsi_generic_read(struct mipi_dsi_device *dsi, const 
> > void *params,
> >                     size_t num_params, void *data, size_t size);
> >   #define mipi_dsi_msleep(ctx, delay)    \
> > @@ -432,8 +434,22 @@ void mipi_dsi_dcs_set_tear_on_multi(struct 
> > mipi_dsi_multi_context *ctx,
> >           static const u8 d[] = { cmd, seq };                     \
> >           mipi_dsi_dcs_write_buffer_multi(ctx, d, ARRAY_SIZE(d)); \
> >       } while (0)
> > +/**
> > + * mipi_dsi_dcs_write_long_multi - transmit a DCS long command with 
> > payload
> > + * @ctx: Context for multiple DSI transactions
> > + * @cmd: Commands
> > + * @seq: buffer containing data to be transmitted
> > + */
> > +#define mipi_dsi_dcs_write_long_multi(ctx, cmd, 
> > seq...)                    \
> > +    do {                                                               \
> > +        static const u8 d[] = { cmd, seq };                        \
> > +        mipi_dsi_generic_write_raw_multi(ctx,                      \
> > +                          MIPI_DSI_DCS_LONG_WRITE, \
> > +                          d, ARRAY_SIZE(d));       \
> > +    } while (0)
> > +
> >   /**
> >    * struct mipi_dsi_driver - DSI driver
> >    * @driver: device driver model driver
> >    * @probe: callback for device binding
> >
> > --
> > 2.45.0