[PATCH 3/5] drm/mipi-dbi: Make bits per word configurable for pixel transfers

[Noralf Trønnes via B4 Relay]

From: Noralf Trønnes <nor...@tronnes.org>

This prepares for supporting other pixel formats than RGB565.

Signed-off-by: Noralf Trønnes <nor...@tronnes.org>
---
 drivers/gpu/drm/drm_mipi_dbi.c | 14 ++++++++++----
 include/drm/drm_mipi_dbi.h     |  5 +++++
 2 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/drm_mipi_dbi.c b/drivers/gpu/drm/drm_mipi_dbi.c
index fa8aba6dc81c..77f8a828d6e0 100644
--- a/drivers/gpu/drm/drm_mipi_dbi.c
+++ b/drivers/gpu/drm/drm_mipi_dbi.c
@@ -1079,7 +1079,7 @@ static int mipi_dbi_typec1_command_read(struct mipi_dbi 
*dbi, u8 *cmd,
 static int mipi_dbi_typec1_command(struct mipi_dbi *dbi, u8 *cmd,
                                   u8 *parameters, size_t num)
 {
-       unsigned int bpw = (*cmd == MIPI_DCS_WRITE_MEMORY_START) ? 16 : 8;
+       unsigned int bpw = 8;
        int ret;
 
        if (mipi_dbi_command_is_read(dbi, *cmd))
@@ -1091,6 +1091,9 @@ static int mipi_dbi_typec1_command(struct mipi_dbi *dbi, 
u8 *cmd,
        if (ret || !num)
                return ret;
 
+       if (*cmd == MIPI_DCS_WRITE_MEMORY_START)
+               bpw = dbi->write_memory_bpw;
+
        return mipi_dbi_spi1_transfer(dbi, 1, parameters, num, bpw);
 }
 
@@ -1184,8 +1187,8 @@ static int mipi_dbi_typec3_command(struct mipi_dbi *dbi, 
u8 *cmd,
        if (ret || !num)
                return ret;
 
-       if (*cmd == MIPI_DCS_WRITE_MEMORY_START && !dbi->swap_bytes)
-               bpw = 16;
+       if (*cmd == MIPI_DCS_WRITE_MEMORY_START)
+               bpw = dbi->write_memory_bpw;
 
        spi_bus_lock(spi->controller);
        gpiod_set_value_cansleep(dbi->dc, 1);
@@ -1256,12 +1259,15 @@ int mipi_dbi_spi_init(struct spi_device *spi, struct 
mipi_dbi *dbi,
 
        dbi->spi = spi;
        dbi->read_commands = mipi_dbi_dcs_read_commands;
+       dbi->write_memory_bpw = 16;
 
        if (dc) {
                dbi->command = mipi_dbi_typec3_command;
                dbi->dc = dc;
-               if (!spi_is_bpw_supported(spi, 16))
+               if (!spi_is_bpw_supported(spi, 16)) {
+                       dbi->write_memory_bpw = 8;
                        dbi->swap_bytes = true;
+               }
        } else {
                dbi->command = mipi_dbi_typec1_command;
                dbi->tx_buf9_len = SZ_16K;
diff --git a/include/drm/drm_mipi_dbi.h b/include/drm/drm_mipi_dbi.h
index e8e0f8d39f3a..b36596efdcc3 100644
--- a/include/drm/drm_mipi_dbi.h
+++ b/include/drm/drm_mipi_dbi.h
@@ -56,6 +56,11 @@ struct mipi_dbi {
         */
        struct spi_device *spi;
 
+       /**
+        * @write_memory_bpw: Bits per word used on a 
MIPI_DCS_WRITE_MEMORY_START transfer
+        */
+       unsigned int write_memory_bpw;
+
        /**
         * @dc: Optional D/C gpio.
         */

-- 
2.45.0