Re: [PATCH v3 11/56] drm/omap: dsi: simplify read functions

Laurent Pinchart
2020-11-09T08:28:38Z

Hi Tomi and Sebastian,

Thank you for the patch.

On Thu, Nov 05, 2020 at 02:02:48PM +0200, Tomi Valkeinen wrote:
> From: Sebastian Reichel <sebastian.reichel@collabora.com>
>
> Simplify the read related message handling by using the functionality
> provided by CONFIG_DRM_MIPI_DSI.
>
> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>

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

> ---
> drivers/gpu/drm/omapdrm/dss/dsi.c | 110 +++++++++---------------------
> 1 file changed, 34 insertions(+), 76 deletions(-)
>
> diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
> index e1595c0608f2..bbdc52ee3559 100644
> --- a/drivers/gpu/drm/omapdrm/dss/dsi.c
> +++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
> @@ -2742,60 +2742,6 @@ static int dsi_vc_write_common(struct omap_dss_device *dssdev,
> return 0;
> }
>
> -static int dsi_vc_dcs_send_read_request(struct dsi_data *dsi, int channel,
> - u8 dcs_cmd)
> -{
> - int r;
> -
> - if (dsi->debug_read)
> - DSSDBG("dsi_vc_dcs_send_read_request(ch%d, dcs_cmd %x)\n",
> - channel, dcs_cmd);
> -
> - r = dsi_vc_send_short(dsi, channel, MIPI_DSI_DCS_READ, dcs_cmd, 0);
> - if (r) {
> - DSSERR("dsi_vc_dcs_send_read_request(ch %d, cmd 0x%02x)"
> - " failed\n", channel, dcs_cmd);
> - return r;
> - }
> -
> - return 0;
> -}
> -
> -static int dsi_vc_generic_send_read_request(struct dsi_data *dsi, int channel,
> - const u8 *reqdata, int reqlen)
> -{
> - u16 data;
> - u8 data_type;
> - int r;
> -
> - if (dsi->debug_read)
> - DSSDBG("dsi_vc_generic_send_read_request(ch %d, reqlen %d)\n",
> - channel, reqlen);
> -
> - if (reqlen == 0) {
> - data_type = MIPI_DSI_GENERIC_READ_REQUEST_0_PARAM;
> - data = 0;
> - } else if (reqlen == 1) {
> - data_type = MIPI_DSI_GENERIC_READ_REQUEST_1_PARAM;
> - data = reqdata[0];
> - } else if (reqlen == 2) {
> - data_type = MIPI_DSI_GENERIC_READ_REQUEST_2_PARAM;
> - data = reqdata[0] | (reqdata[1] << 8);
> - } else {
> - BUG();
> - return -EINVAL;
> - }
> -
> - r = dsi_vc_send_short(dsi, channel, data_type, data, 0);
> - if (r) {
> - DSSERR("dsi_vc_generic_send_read_request(ch %d, reqlen %d)"
> - " failed\n", channel, reqlen);
> - return r;
> - }
> -
> - return 0;
> -}
> -
> static int dsi_vc_read_rx_fifo(struct dsi_data *dsi, int channel, u8 *buf,
> int buflen, enum dss_dsi_content_type type)
> {
> @@ -2904,13 +2850,18 @@ static int dsi_vc_read_rx_fifo(struct dsi_data *dsi, int channel, u8 *buf,
> return r;
> }
>
> -static int dsi_vc_dcs_read(struct omap_dss_device *dssdev, int channel, u8 dcs_cmd,
> - u8 *buf, int buflen)
> +static int dsi_vc_dcs_read(struct omap_dss_device *dssdev,
> + const struct mipi_dsi_msg *msg)
> {
> struct dsi_data *dsi = to_dsi_data(dssdev);
> + u8 dcs_cmd = ((u8 *)msg->tx_buf)[0];
> + u8 channel = msg->channel;
> int r;
>
> - r = dsi_vc_dcs_send_read_request(dsi, channel, dcs_cmd);
> + if (dsi->debug_read)
> + DSSDBG("%s(ch %d, cmd %x)\n", __func__, channel, dcs_cmd);
> +
> + r = dsi_vc_send_short(dsi, channel, MIPI_DSI_DCS_READ, dcs_cmd, 0);
> if (r)
> goto err;
>
> @@ -2918,47 +2869,58 @@ static int dsi_vc_dcs_read(struct omap_dss_device *dssdev, int channel, u8 dcs_c
> if (r)
> goto err;
>
> - r = dsi_vc_read_rx_fifo(dsi, channel, buf, buflen,
> + r = dsi_vc_read_rx_fifo(dsi, channel, msg->rx_buf, msg->rx_len,
> DSS_DSI_CONTENT_DCS);
> if (r < 0)
> goto err;
>
> - if (r != buflen) {
> + if (r != msg->rx_len) {
> r = -EIO;
> goto err;
> }
>
> return 0;
> err:
> - DSSERR("dsi_vc_dcs_read(ch %d, cmd 0x%02x) failed\n", channel, dcs_cmd);
> + DSSERR("%s(ch %d, cmd 0x%02x) failed\n", __func__, msg->channel, dcs_cmd);
> return r;
> }
>
> -static int dsi_vc_generic_read(struct omap_dss_device *dssdev, int channel,
> - const u8 *reqdata, int reqlen, u8 *buf, int buflen)
> +static int dsi_vc_generic_read(struct omap_dss_device *dssdev,
> + const struct mipi_dsi_msg *msg)
> {
> struct dsi_data *dsi = to_dsi_data(dssdev);
> + struct mipi_dsi_packet packet;
> + u16 data;
> int r;
>
> - r = dsi_vc_generic_send_read_request(dsi, channel, reqdata, reqlen);
> + r = mipi_dsi_create_packet(&packet, msg);
> + if (r < 0)
> + goto err;
> +
> + data = packet.header[1] | (packet.header[2] << 8);
> +
> + r = dsi_vc_send_short(dsi, msg->channel, msg->type, data, 0);
> if (r)
> - return r;
> + goto err;
>
> - r = dsi_vc_send_bta_sync(dssdev, channel);
> + r = dsi_vc_send_bta_sync(dssdev, msg->channel);
> if (r)
> - return r;
> + goto err;
>
> - r = dsi_vc_read_rx_fifo(dsi, channel, buf, buflen,
> + r = dsi_vc_read_rx_fifo(dsi, msg->channel, msg->rx_buf, msg->rx_len,
> DSS_DSI_CONTENT_GENERIC);
> if (r < 0)
> - return r;
> + goto err;
>
> - if (r != buflen) {
> + if (r != msg->rx_len) {
> r = -EIO;
> - return r;
> + goto err;
> }
>
> return 0;
> +err:
> + DSSERR("%s(ch %d, reqlen %d) failed\n", __func__, msg->channel, msg->tx_len);
> + return r;
> }
>
> static int dsi_enter_ulps(struct dsi_data *dsi)
> @@ -4775,13 +4737,9 @@ static ssize_t omap_dsi_transfer(struct omap_dss_device *dssdev,
> 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);
> + return dsi_vc_generic_read(dssdev, msg);
> case MIPI_DSI_DCS_READ:
> - return dsi_vc_dcs_read(dssdev, msg->channel,
> - ((u8 *)msg->tx_buf)[0],
> - msg->rx_buf, msg->rx_len);
> + return dsi_vc_dcs_read(dssdev, msg);
> }
>
> return -EINVAL;

--
Regards,

Laurent Pinchart