On Sun, Jan 29, 2017 at 01:24:44PM +0000, John Keeping wrote:
I haven't found any method for getting the length of a response, so this just uses the requested rx_len
Signed-off-by: John Keeping john@metanate.com
v3:
- Fix checkpatch warnings
Unchanged in v2
drivers/gpu/drm/rockchip/dw-mipi-dsi.c | 56 ++++++++++++++++++++++++++++++++++ 1 file changed, 56 insertions(+)
diff --git a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c index cf3ca6b0cbdb..cc58ada75425 100644 --- a/drivers/gpu/drm/rockchip/dw-mipi-dsi.c +++ b/drivers/gpu/drm/rockchip/dw-mipi-dsi.c @@ -678,6 +678,56 @@ static int dw_mipi_dsi_dcs_long_write(struct dw_mipi_dsi *dsi, return dw_mipi_dsi_gen_pkt_hdr_write(dsi, hdr_val); }
+static int dw_mipi_dsi_dcs_read(struct dw_mipi_dsi *dsi,
const struct mipi_dsi_msg *msg)
+{
- const u8 *tx_buf = msg->tx_buf;
- u8 *rx_buf = msg->rx_buf;
- size_t i;
- int ret, val;
- dsi_write(dsi, DSI_PCKHDL_CFG, EN_CRC_RX | EN_ECC_RX | EN_BTA);
- dsi_write(dsi, DSI_GEN_HDR,
GEN_HDATA(tx_buf[0]) | GEN_HTYPE(msg->type));
- ret = readl_poll_timeout(dsi->base + DSI_CMD_PKT_STATUS,
val, !(val & GEN_RD_CMD_BUSY), 1000,
CMD_PKT_STATUS_TIMEOUT_US);
- if (ret < 0) {
dev_err(dsi->dev, "failed to read command response\n");
return ret;
- }
- for (i = 0; i < msg->rx_len;) {
u32 pld = dsi_read(dsi, DSI_GEN_PLD_DATA);
while (i < msg->rx_len) {
rx_buf[i] = pld & 0xff;
pld >>= 8;
i++;
}
- }
AFAICT, the outer for loop just initializes i and ensures msg->rx_len is non-zero?
I think the following would be easier to read (and safe against the case where msg->rx_len > sizeof(pld) (even though this shouldn't happen according to DCS spec)).
if (msg->rx_len > 0) { u32 pld = dsi_read(dsi, DSI_GEN_PLD_DATA); memcpy(rx_buf, &pld, MIN(msg->rx_len, sizeof(pld)); }
- return msg->rx_len;
+}
+static int dw_mipi_dsi_set_max_return_packet_size(struct dw_mipi_dsi *dsi,
size_t len)
+{
- u8 val[] = { len & 0xff, (len >> 8) & 0xff };
- struct mipi_dsi_msg msg = {
.channel = dsi->channel,
.type = MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE,
.tx_buf = val,
.tx_len = 2,
- };
- if (len > 0xffff)
return -EINVAL;
- return dw_mipi_dsi_dcs_short_write(dsi, &msg);
+}
static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host, const struct mipi_dsi_msg *msg) { @@ -695,6 +745,12 @@ static ssize_t dw_mipi_dsi_host_transfer(struct mipi_dsi_host *host, case MIPI_DSI_DCS_LONG_WRITE: ret = dw_mipi_dsi_dcs_long_write(dsi, msg); break;
- case MIPI_DSI_DCS_READ:
ret = dw_mipi_dsi_set_max_return_packet_size(dsi, msg->rx_len);
if (ret < 0)
return ret;
ret = dw_mipi_dsi_dcs_read(dsi, msg);
default: dev_err(dsi->dev, "unsupported message type 0x%02x\n", msg->type);break;
-- 2.11.0.197.gb556de5.dirty
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