drm/bridge/synopsys: dsi: use common mipi_dsi_create_packet()

This takes care of 2 TODOs in this driver, by using the common DSI
packet-marshalling code instead of our custom short/long write code.
This both saves us some duplicated code and gets us free support for
command types that weren't already part of our switch block (e.g.,
MIPI_DSI_GENERIC_LONG_WRITE).

The code logic stays mostly intact, except that it becomes unnecessary
to split the short/long write functions, and we have to copy data a bit
more.

Along the way, I noticed that loop bounds were a little odd:

	while (DIV_ROUND_UP(len, pld_data_bytes))

This really was just supposed to be 'len != 0', so I made that more
clear.

Tested on RK3399 with some pending refactoring patches by Nickey Yang,
to make the Rockchip DSI driver wrap this common driver.

Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Philippe Cornu <philippe.cornu@st.com>
Tested-by: Philippe Cornu <philippe.cornu@st.com>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20180109203248.139249-1-briannorris@chromium.org

diff --git a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
index 247605271d41d4a821f59d09f0db4d3b610e474c..8d90079707ea7c8491d51fd3dfc508cbd3eb1dec 100644 (file)
--- a/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
+++ b/drivers/gpu/drm/bridge/synopsys/dw-mipi-dsi.c
@@ -136,10 +136,6 @@
                                         GEN_SW_0P_TX_LP)
 
 #define DSI_GEN_HDR                    0x6c
-/* TODO These 2 defines will be reworked thanks to mipi_dsi_create_packet() */
-#define GEN_HDATA(data)                        (((data) & 0xffff) << 8)
-#define GEN_HTYPE(type)                        (((type) & 0xff) << 0)
-
 #define DSI_GEN_PLD_DATA               0x70
 
 #define DSI_CMD_PKT_STATUS             0x74
@@ -359,44 +355,15 @@ static int dw_mipi_dsi_gen_pkt_hdr_write(struct dw_mipi_dsi *dsi, u32 hdr_val)
        return 0;
 }
 
-static int dw_mipi_dsi_dcs_short_write(struct dw_mipi_dsi *dsi,
-                                      const struct mipi_dsi_msg *msg)
-{
-       const u8 *tx_buf = msg->tx_buf;
-       u16 data = 0;
-       u32 val;
-
-       if (msg->tx_len > 0)
-               data |= tx_buf[0];
-       if (msg->tx_len > 1)
-               data |= tx_buf[1] << 8;
-
-       if (msg->tx_len > 2) {
-               dev_err(dsi->dev, "too long tx buf length %zu for short write\n",
-                       msg->tx_len);
-               return -EINVAL;
-       }
-
-       val = GEN_HDATA(data) | GEN_HTYPE(msg->type);
-       return dw_mipi_dsi_gen_pkt_hdr_write(dsi, val);
-}
-
-static int dw_mipi_dsi_dcs_long_write(struct dw_mipi_dsi *dsi,
-                                     const struct mipi_dsi_msg *msg)
+static int dw_mipi_dsi_write(struct dw_mipi_dsi *dsi,
+                            const struct mipi_dsi_packet *packet)
 {
-       const u8 *tx_buf = msg->tx_buf;
-       int len = msg->tx_len, pld_data_bytes = sizeof(u32), ret;
-       u32 hdr_val = GEN_HDATA(msg->tx_len) | GEN_HTYPE(msg->type);
+       const u8 *tx_buf = packet->payload;
+       int len = packet->payload_length, pld_data_bytes = sizeof(u32), ret;
        u32 remainder;
        u32 val;
 
-       if (msg->tx_len < 3) {
-               dev_err(dsi->dev, "wrong tx buf length %zu for long write\n",
-                       msg->tx_len);
-               return -EINVAL;
-       }
-
-       while (DIV_ROUND_UP(len, pld_data_bytes)) {
+       while (len) {
                if (len < pld_data_bytes) {
                        remainder = 0;
                        memcpy(&remainder, tx_buf, len);
@@ -419,40 +386,27 @@ static int dw_mipi_dsi_dcs_long_write(struct dw_mipi_dsi *dsi,
                }
        }
 
-       return dw_mipi_dsi_gen_pkt_hdr_write(dsi, hdr_val);
+       remainder = 0;
+       memcpy(&remainder, packet->header, sizeof(packet->header));
+       return dw_mipi_dsi_gen_pkt_hdr_write(dsi, remainder);
 }
 
 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;
 
-       /*
-        * TODO dw drv improvements
-        * use mipi_dsi_create_packet() instead of all following
-        * functions and code (no switch cases, no
-        * dw_mipi_dsi_dcs_short_write(), only the loop in long_write...)
-        * and use packet.header...
-        */
-       dw_mipi_message_config(dsi, msg);
-
-       switch (msg->type) {
-       case MIPI_DSI_DCS_SHORT_WRITE:
-       case MIPI_DSI_DCS_SHORT_WRITE_PARAM:
-       case MIPI_DSI_SET_MAXIMUM_RETURN_PACKET_SIZE:
-               ret = dw_mipi_dsi_dcs_short_write(dsi, msg);
-               break;
-       case MIPI_DSI_DCS_LONG_WRITE:
-               ret = dw_mipi_dsi_dcs_long_write(dsi, msg);
-               break;
-       default:
-               dev_err(dsi->dev, "unsupported message type 0x%02x\n",
-                       msg->type);
-               ret = -EINVAL;
+       ret = mipi_dsi_create_packet(&packet, msg);
+       if (ret) {
+               dev_err(dsi->dev, "failed to create packet: %d\n", ret);
+               return ret;
        }
 
-       return ret;
+       dw_mipi_message_config(dsi, msg);
+
+       return dw_mipi_dsi_write(dsi, &packet);
 }
 
 static const struct mipi_dsi_host_ops dw_mipi_dsi_host_ops = {