Multiple displays may be connected to the same bus and share a D/C GPIO,
so the display driver needs exclusive access to the bus to ensure that
it can control the D/C GPIO safely.
Signed-off-by: Otto Pflüger <otto.pflue...@abscue.de>
Reviewed-by: Noralf Trønnes <nor...@tronnes.org>
---
drivers/gpu/drm/drm_mipi_dbi.c | 17 +++++++++++++----
drivers/gpu/drm/tiny/ili9225.c | 7 ++++++-
drivers/gpu/drm/tiny/ili9486.c | 4 ++++
3 files changed, 23 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/drm_mipi_dbi.c b/drivers/gpu/drm/drm_mipi_dbi.c
index c871d9f096b8..e90f0bf895b3 100644
--- a/drivers/gpu/drm/drm_mipi_dbi.c
+++ b/drivers/gpu/drm/drm_mipi_dbi.c
@@ -1140,10 +1140,13 @@ static int mipi_dbi_typec3_command_read(struct mipi_dbi
*dbi, u8 *cmd,
return -ENOMEM;
tr[1].rx_buf = buf;
+
+ spi_bus_lock(spi->controller);
gpiod_set_value_cansleep(dbi->dc, 0);
spi_message_init_with_transfers(&m, tr, ARRAY_SIZE(tr));
- ret = spi_sync(spi, &m);
+ ret = spi_sync_locked(spi, &m);
+ spi_bus_unlock(spi->controller);
if (ret)
goto err_free;
@@ -1177,19 +1180,24 @@ static int mipi_dbi_typec3_command(struct mipi_dbi
*dbi, u8 *cmd,
MIPI_DBI_DEBUG_COMMAND(*cmd, par, num);
+ spi_bus_lock(spi->controller);
gpiod_set_value_cansleep(dbi->dc, 0);
speed_hz = mipi_dbi_spi_cmd_max_speed(spi, 1);
ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, cmd, 1);
+ spi_bus_unlock(spi->controller);
if (ret || !num)
return ret;
if (*cmd == MIPI_DCS_WRITE_MEMORY_START && !dbi->swap_bytes)
bpw = 16;
+ spi_bus_lock(spi->controller);
gpiod_set_value_cansleep(dbi->dc, 1);
speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);
+ ret = mipi_dbi_spi_transfer(spi, speed_hz, bpw, par, num);
+ spi_bus_unlock(spi->controller);
- return mipi_dbi_spi_transfer(spi, speed_hz, bpw, par, num);
+ return ret;
}
/**
@@ -1271,7 +1279,8 @@ EXPORT_SYMBOL(mipi_dbi_spi_init);
* @len: Buffer length
*
* This SPI transfer helper breaks up the transfer of @buf into chunks which
- * the SPI controller driver can handle.
+ * the SPI controller driver can handle. The SPI bus must be locked when
+ * calling this.
*
* Returns:
* Zero on success, negative error code on failure.
@@ -1305,7 +1314,7 @@ int mipi_dbi_spi_transfer(struct spi_device *spi, u32
speed_hz,
buf += chunk;
len -= chunk;
- ret = spi_sync(spi, &m);
+ ret = spi_sync_locked(spi, &m);
if (ret)
return ret;
}
diff --git a/drivers/gpu/drm/tiny/ili9225.c b/drivers/gpu/drm/tiny/ili9225.c
index 077c6ff5a2e1..4ceb68ffac4b 100644
--- a/drivers/gpu/drm/tiny/ili9225.c
+++ b/drivers/gpu/drm/tiny/ili9225.c
@@ -316,19 +316,24 @@ static int ili9225_dbi_command(struct mipi_dbi *dbi, u8
*cmd, u8 *par,
u32 speed_hz;
int ret;
+ spi_bus_lock(spi->controller);
gpiod_set_value_cansleep(dbi->dc, 0);
speed_hz = mipi_dbi_spi_cmd_max_speed(spi, 1);
ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, cmd, 1);
+ spi_bus_unlock(spi->controller);
if (ret || !num)
return ret;
if (*cmd == ILI9225_WRITE_DATA_TO_GRAM && !dbi->swap_bytes)
bpw = 16;
+ spi_bus_lock(spi->controller);
gpiod_set_value_cansleep(dbi->dc, 1);
speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);
+ ret = mipi_dbi_spi_transfer(spi, speed_hz, bpw, par, num);
+ spi_bus_unlock(spi->controller);
- return mipi_dbi_spi_transfer(spi, speed_hz, bpw, par, num);
+ return ret;
}
static const struct drm_simple_display_pipe_funcs ili9225_pipe_funcs = {
diff --git a/drivers/gpu/drm/tiny/ili9486.c b/drivers/gpu/drm/tiny/ili9486.c
index 02265c898816..938bceed5999 100644
--- a/drivers/gpu/drm/tiny/ili9486.c
+++ b/drivers/gpu/drm/tiny/ili9486.c
@@ -59,9 +59,11 @@ static int waveshare_command(struct mipi_dbi *mipi, u8 *cmd,
u8 *par,
* before being transferred as 8-bit on the big endian SPI bus.
*/
buf[0] = cpu_to_be16(*cmd);
+ spi_bus_lock(spi->controller);
gpiod_set_value_cansleep(mipi->dc, 0);
speed_hz = mipi_dbi_spi_cmd_max_speed(spi, 2);
ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, buf, 2);
+ spi_bus_unlock(spi->controller);
if (ret || !num)
goto free;
@@ -79,9 +81,11 @@ static int waveshare_command(struct mipi_dbi *mipi, u8 *cmd,
u8 *par,
if (*cmd == MIPI_DCS_WRITE_MEMORY_START && !mipi->swap_bytes)
bpw = 16;
+ spi_bus_lock(spi->controller);
gpiod_set_value_cansleep(mipi->dc, 1);
speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);
ret = mipi_dbi_spi_transfer(spi, speed_hz, bpw, data, num);
+ spi_bus_unlock(spi->controller);
free:
kfree(buf);
--
2.39.1
