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drm/bridge/synopsys: dsi: Add read feature 

This patch adds the DCS/GENERIC DSI read feature.

Signed-off-by: Philippe Cornu <philippe.cornu@st.com>
Reviewed-by: Andrzej Hajda <a.hajda@samsung.com>
Reviewed-by: Brian Norris <briannorris@chromium.org>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180204213104.17834-1-philippe.cornu@st.com
This commit is contained in:
Philippe Cornu 2018-02-04 22:31:04 +01:00 committed by Andrzej Hajda
parent 3b6ec45857
commit a009c53e8d
1 changed files with 45 additions and 13 deletions
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58
drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
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@ -391,18 +391,46 @@ 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) {
@ -416,12 +444,16 @@ 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 = {