Hi, On Sun, Feb 04, 2018 at 10:31:04PM +0100, Philippe Cornu wrote: > This patch adds the DCS/GENERIC DSI read feature. > > Signed-off-by: Philippe Cornu <philippe.cornu@xxxxxx> > --- > Extra notes: > DSI read tests have been performed with DCS & GENERIC, short & long > commands, on two different panels. > The maximum fifo size (32*32-bit = 128 bytes on stm32) has been > verified too. Seems OK to me, just comparing with work we've been borrowing from Rockchip: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/863347 (And in fact, it looks much better than that.) So FWIW: Reviewed-by: Brian Norris <briannorris@xxxxxxxxxxxx> and thanks a bunch! Brian > drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c | 58 +++++++++++++++++++++------ > 1 file changed, 45 insertions(+), 13 deletions(-) > > diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c > index e9422d05e897..65aeb3f78b48 100644 > --- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c > +++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c > @@ -397,18 +397,46 @@ static int dw_mipi_dsi_write(struct dw_mipi_dsi *dsi, > return dw_mipi_dsi_gen_pkt_hdr_write(dsi, le32_to_cpu(word)); > } > > +static int dw_mipi_dsi_read(struct dw_mipi_dsi *dsi, > + const struct mipi_dsi_msg *msg) > +{ > + int i, j, ret, len = msg->rx_len; > + u8 *buf = msg->rx_buf; > + u32 val; > + > + /* Wait end of the read operation */ > + ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS, > + val, !(val & GEN_RD_CMD_BUSY), > + 1000, CMD_PKT_STATUS_TIMEOUT_US); > + if (ret) { > + dev_err(dsi->dev, "Timeout during read operation\n"); > + return ret; > + } > + > + for (i = 0; i < len; i += 4) { > + /* Read fifo must not be empty before all bytes are read */ > + ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS, > + val, !(val & GEN_PLD_R_EMPTY), > + 1000, CMD_PKT_STATUS_TIMEOUT_US); > + if (ret) { > + dev_err(dsi->dev, "Read payload FIFO is empty\n"); > + return ret; > + } > + > + val = dsi_read(dsi, DSI_GEN_PLD_DATA); > + for (j = 0; j < 4 && j + i < len; j++) > + buf[i + j] = val >> (8 * j); > + } > + > + return ret; > +} > + > static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host, > const struct mipi_dsi_msg *msg) > { > struct dw_mipi_dsi *dsi = host_to_dsi(host); > struct mipi_dsi_packet packet; > - int ret; > - > - if (msg->rx_buf || msg->rx_len) { > - /* TODO dw drv improvements: implement read feature */ > - dev_warn(dsi->dev, "read operations not yet implemented\n"); > - return -EINVAL; > - } > + int ret, nb_bytes; > > ret = mipi_dsi_create_packet(&packet, msg); > if (ret) { > @@ -422,12 +450,16 @@ static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host, > if (ret) > return ret; > > - /* > - * TODO Only transmitted size is returned as actual driver does > - * not support dcs/generic reads. Please update return value when > - * delivering the read feature. > - */ > - return packet.size; > + if (msg->rx_buf && msg->rx_len) { > + ret = dw_mipi_dsi_read(dsi, msg); > + if (ret) > + return ret; > + nb_bytes = msg->rx_len; > + } else { > + nb_bytes = packet.size; > + } > + > + return nb_bytes; > } > > static const struct mipi_dsi_host_ops dw_mipi_dsi_host_ops = { > -- > 2.15.1 > _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/dri-devel
