Re: [PATCH v3 06/56] drm/omap: dsi: add generic transfer function

Laurent Pinchart
2020-11-06T05:05:37Z

Hi Tomi and Sebastian,

Thank you for the patch.

On Thu, Nov 05, 2020 at 02:02:43PM +0200, Tomi Valkeinen wrote:
> From: Sebastian Reichel <sebastian.reichel@collabora.com>
>
> This prepares the driver for becoming a mipi_dsi_host implementation,
> which provides a generic transfer function instead of all kind of
> different read/write functions. The implementation will become more
> elegant after unexporting the specific functions in the following
> patches.
>
> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
> ---
> drivers/gpu/drm/omapdrm/dss/dsi.c | 54 +++++++++++++++++++++++++++
> drivers/gpu/drm/omapdrm/dss/omapdss.h | 3 ++
> 2 files changed, 57 insertions(+)
>
> diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
> index 22d74d762a10..59a62d1d41cb 100644
> --- a/drivers/gpu/drm/omapdrm/dss/dsi.c
> +++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
> @@ -4842,6 +4842,58 @@ static void dsi_release_vc(struct omap_dss_device *dssdev, int channel)
> }
> }
>
> +static ssize_t omap_dsi_transfer(struct omap_dss_device *dssdev,
> + const struct mipi_dsi_msg *msg)
> +{
> + /*
> + * no_sync can be used to optimize performance by sending e.g. column

Can we start this with "TODO: no_sync can ..." to make it standout as
something to be addressed ?

> + * and page information without syncing in between. It's not absolutley

s/absolutley/absolutely/

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> + * required, so postpone this feature for now.
> + */
> + bool no_sync = false;
> + u16 val;
> +
> + switch (msg->type) {
> + case MIPI_DSI_GENERIC_SHORT_WRITE_0_PARAM:
> + case MIPI_DSI_GENERIC_SHORT_WRITE_1_PARAM:
> + case MIPI_DSI_GENERIC_SHORT_WRITE_2_PARAM:
> + case MIPI_DSI_GENERIC_LONG_WRITE:
> + if (no_sync)
> + return dsi_vc_generic_write_nosync(dssdev, msg->channel,
> + msg->tx_buf,
> + msg->tx_len);
> + else
> + return dsi_vc_generic_write(dssdev, msg->channel,
> + msg->tx_buf, msg->tx_len);
> + case MIPI_DSI_DCS_SHORT_WRITE:
> + case MIPI_DSI_DCS_SHORT_WRITE_PARAM:
> + case MIPI_DSI_DCS_LONG_WRITE:
> + if (no_sync)
> + return dsi_vc_dcs_write_nosync(dssdev, msg->channel,
> + msg->tx_buf,
> + msg->tx_len);
> + else
> + return dsi_vc_dcs_write(dssdev, msg->channel,
> + msg->tx_buf, msg->tx_len);
> + case MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM:
> + case MIPI_DSI_GENERIC_READ_REQUEST_1_PARAM:
> + case MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM:
> + return dsi_vc_generic_read(dssdev, msg->channel,
> + msg->tx_buf, msg->tx_len,
> + msg->rx_buf, msg->rx_len);
> + case MIPI_DSI_DCS_READ:
> + return dsi_vc_dcs_read(dssdev, msg->channel,
> + ((u8 *)msg->tx_buf)[0],
> + msg->rx_buf, msg->rx_len);
> + case MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE:
> + val = le16_to_cpu(*((__le16 *)msg->tx_buf));
> + return dsi_vc_set_max_rx_packet_size(dssdev, msg->channel, val);
> + case MIPI_DSI_NULL_PACKET:
> + return dsi_vc_send_null(to_dsi_data(dssdev), msg->channel);
> + }
> +
> + return -EINVAL;
> +}
>
> static int dsi_get_clocks(struct dsi_data *dsi)
> {
> @@ -4896,6 +4948,8 @@ static const struct omap_dss_device_ops dsi_ops = {
> .set_vc_id = dsi_set_vc_id,
> .release_vc = dsi_release_vc,
>
> + .transfer = omap_dsi_transfer,
> +
> .dcs_write = dsi_vc_dcs_write,
> .dcs_write_nosync = dsi_vc_dcs_write_nosync,
> .dcs_read = dsi_vc_dcs_read,
> diff --git a/drivers/gpu/drm/omapdrm/dss/omapdss.h b/drivers/gpu/drm/omapdrm/dss/omapdss.h
> index 8e96ab2f20b6..654618e5a4e5 100644
> --- a/drivers/gpu/drm/omapdrm/dss/omapdss.h
> +++ b/drivers/gpu/drm/omapdrm/dss/omapdss.h
> @@ -308,6 +308,9 @@ struct omapdss_dsi_ops {
> void (*release_vc)(struct omap_dss_device *dssdev, int channel);
>
> /* data transfer */
> + ssize_t (*transfer)(struct omap_dss_device *dssdev,
> + const struct mipi_dsi_msg *msg);
> +
> int (*dcs_write)(struct omap_dss_device *dssdev, int channel,
> const u8 *data, int len);
> int (*dcs_write_nosync)(struct omap_dss_device *dssdev, int channel,

--
Regards,

Laurent Pinchart