[PATCH v2] drm/mcde: Fix DSI transfers
There were bugs in the DSI transfer (read and write) function
as it was only tested with displays ever needing a single byte
to be written. Fixed it up and tested so we can now write
messages of up to 16 bytes and read up to 4 bytes from the
display.
Tested with a Sony ACX424AKP display: this display now self-
identifies and can control backlight in command mode.
Cc: Stephan Gerhold
Reported-by: kbuild test robot
Fixes: 5fc537bfd000 ("drm/mcde: Add new driver for ST-Ericsson MCDE")
Signed-off-by: Linus Walleij
---
ChangeLog v1->v2:
- Fix a print modifier for dev_err() found by the build robot.
---
drivers/gpu/drm/mcde/mcde_dsi.c | 70 ++---
1 file changed, 47 insertions(+), 23 deletions(-)
diff --git a/drivers/gpu/drm/mcde/mcde_dsi.c b/drivers/gpu/drm/mcde/mcde_dsi.c
index 07f7090d08b3..90659d190d78 100644
--- a/drivers/gpu/drm/mcde/mcde_dsi.c
+++ b/drivers/gpu/drm/mcde/mcde_dsi.c
@@ -178,22 +178,26 @@ static ssize_t mcde_dsi_host_transfer(struct
mipi_dsi_host *host,
const u32 loop_delay_us = 10; /* us */
const u8 *tx = msg->tx_buf;
u32 loop_counter;
- size_t txlen;
+ size_t txlen = msg->tx_len;
+ size_t rxlen = msg->rx_len;
u32 val;
int ret;
int i;
- txlen = msg->tx_len;
- if (txlen > 12) {
+ if (txlen > 16) {
dev_err(d->dev,
- "dunno how to write more than 12 bytes yet\n");
+ "dunno how to write more than 16 bytes yet\n");
+ return -EIO;
+ }
+ if (rxlen > 4) {
+ dev_err(d->dev,
+ "dunno how to read more than 4 bytes yet\n");
return -EIO;
}
dev_dbg(d->dev,
- "message to channel %d, %zd bytes",
- msg->channel,
- txlen);
+ "message to channel %d, write %zd bytes read %zd bytes\n",
+ msg->channel, txlen, rxlen);
/* Command "nature" */
if (MCDE_DSI_HOST_IS_READ(msg->type))
@@ -210,9 +214,7 @@ static ssize_t mcde_dsi_host_transfer(struct mipi_dsi_host
*host,
if (mipi_dsi_packet_format_is_long(msg->type))
val |= DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_LONGNOTSHORT;
val |= 0 << DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_ID_SHIFT;
- /* Add one to the length for the MIPI DCS command */
- val |= txlen
- << DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_SIZE_SHIFT;
+ val |= txlen << DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_SIZE_SHIFT;
val |= DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_LP_EN;
val |= msg->type << DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_HEAD_SHIFT;
writel(val, d->regs + DSI_DIRECT_CMD_MAIN_SETTINGS);
@@ -249,17 +251,36 @@ static ssize_t mcde_dsi_host_transfer(struct
mipi_dsi_host *host,
writel(1, d->regs + DSI_DIRECT_CMD_SEND);
loop_counter = 1000 * 1000 / loop_delay_us;
- while (!(readl(d->regs + DSI_DIRECT_CMD_STS) &
-DSI_DIRECT_CMD_STS_WRITE_COMPLETED)
- && --loop_counter)
- usleep_range(loop_delay_us, (loop_delay_us * 3) / 2);
-
- if (!loop_counter) {
- dev_err(d->dev, "DSI write timeout!\n");
- return -ETIME;
+ if (MCDE_DSI_HOST_IS_READ(msg->type)) {
+ /* Read command */
+ while (!(readl(d->regs + DSI_DIRECT_CMD_STS) &
+(DSI_DIRECT_CMD_STS_READ_COMPLETED |
+ DSI_DIRECT_CMD_STS_READ_COMPLETED_WITH_ERR))
+ && --loop_counter)
+ usleep_range(loop_delay_us, (loop_delay_us * 3) / 2);
+ if (!loop_counter) {
+ dev_err(d->dev, "DSI write timeout!\n");
+ return -ETIME;
+ }
+ } else {
+ /* Writing only */
+ while (!(readl(d->regs + DSI_DIRECT_CMD_STS) &
+DSI_DIRECT_CMD_STS_WRITE_COMPLETED)
+ && --loop_counter)
+ usleep_range(loop_delay_us, (loop_delay_us * 3) / 2);
+
+ if (!loop_counter) {
+ dev_err(d->dev, "DSI write timeout!\n");
+ return -ETIME;
+ }
}
val = readl(d->regs + DSI_DIRECT_CMD_STS);
+ if (val & DSI_DIRECT_CMD_STS_READ_COMPLETED_WITH_ERR) {
+ dev_err(d->dev, "read completed with error\n");
+ writel(1, d->regs + DSI_DIRECT_CMD_RD_INIT);
+ return -EIO;
+ }
if (val & DSI_DIRECT_CMD_STS_ACKNOWLEDGE_WITH_ERR_RECEIVED) {
val >>= DSI_DIRECT_CMD_STS_ACK_VAL_SHIFT;
dev_err(d->dev, "error during transmission: %04x\n",
@@ -269,10 +290,7 @@ static ssize_t mcde_dsi_host_transfer(struct mipi_dsi_host
*host,
if (!MCDE_DSI_HOST_IS_READ(msg->type)) {
/* Return number of bytes written */
- if (mipi_dsi_packet_
Re: [PATCH v2] drm/mcde: Fix DSI transfers
On Sat, Aug 31, 2019 at 09:50:13AM +0200, Linus Walleij wrote:
> There were bugs in the DSI transfer (read and write) function
> as it was only tested with displays ever needing a single byte
> to be written. Fixed it up and tested so we can now write
> messages of up to 16 bytes and read up to 4 bytes from the
> display.
>
> Tested with a Sony ACX424AKP display: this display now self-
> identifies and can control backlight in command mode.
>
> Cc: Stephan Gerhold
> Reported-by: kbuild test robot
> Fixes: 5fc537bfd000 ("drm/mcde: Add new driver for ST-Ericsson MCDE")
> Signed-off-by: Linus Walleij
> ---
> ChangeLog v1->v2:
> - Fix a print modifier for dev_err() found by the build robot.
> ---
> drivers/gpu/drm/mcde/mcde_dsi.c | 70 ++---
> 1 file changed, 47 insertions(+), 23 deletions(-)
>
> diff --git a/drivers/gpu/drm/mcde/mcde_dsi.c b/drivers/gpu/drm/mcde/mcde_dsi.c
> index 07f7090d08b3..90659d190d78 100644
> --- a/drivers/gpu/drm/mcde/mcde_dsi.c
> +++ b/drivers/gpu/drm/mcde/mcde_dsi.c
> @@ -178,22 +178,26 @@ static ssize_t mcde_dsi_host_transfer(struct
> mipi_dsi_host *host,
> const u32 loop_delay_us = 10; /* us */
> const u8 *tx = msg->tx_buf;
> u32 loop_counter;
> - size_t txlen;
> + size_t txlen = msg->tx_len;
> + size_t rxlen = msg->rx_len;
> u32 val;
> int ret;
> int i;
>
> - txlen = msg->tx_len;
> - if (txlen > 12) {
> + if (txlen > 16) {
> dev_err(d->dev,
> - "dunno how to write more than 12 bytes yet\n");
> + "dunno how to write more than 16 bytes yet\n");
> + return -EIO;
> + }
> + if (rxlen > 4) {
> + dev_err(d->dev,
> + "dunno how to read more than 4 bytes yet\n");
> return -EIO;
> }
>
> dev_dbg(d->dev,
> - "message to channel %d, %zd bytes",
> - msg->channel,
> - txlen);
> + "message to channel %d, write %zd bytes read %zd bytes\n",
> + msg->channel, txlen, rxlen);
>
> /* Command "nature" */
> if (MCDE_DSI_HOST_IS_READ(msg->type))
> @@ -210,9 +214,7 @@ static ssize_t mcde_dsi_host_transfer(struct
> mipi_dsi_host *host,
> if (mipi_dsi_packet_format_is_long(msg->type))
> val |= DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_LONGNOTSHORT;
> val |= 0 << DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_ID_SHIFT;
> - /* Add one to the length for the MIPI DCS command */
> - val |= txlen
> - << DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_SIZE_SHIFT;
> + val |= txlen << DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_SIZE_SHIFT;
> val |= DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_LP_EN;
> val |= msg->type << DSI_DIRECT_CMD_MAIN_SETTINGS_CMD_HEAD_SHIFT;
> writel(val, d->regs + DSI_DIRECT_CMD_MAIN_SETTINGS);
> @@ -249,17 +251,36 @@ static ssize_t mcde_dsi_host_transfer(struct
> mipi_dsi_host *host,
> writel(1, d->regs + DSI_DIRECT_CMD_SEND);
>
> loop_counter = 1000 * 1000 / loop_delay_us;
> - while (!(readl(d->regs + DSI_DIRECT_CMD_STS) &
> - DSI_DIRECT_CMD_STS_WRITE_COMPLETED)
> -&& --loop_counter)
> - usleep_range(loop_delay_us, (loop_delay_us * 3) / 2);
> -
> - if (!loop_counter) {
> - dev_err(d->dev, "DSI write timeout!\n");
> - return -ETIME;
> + if (MCDE_DSI_HOST_IS_READ(msg->type)) {
> + /* Read command */
> + while (!(readl(d->regs + DSI_DIRECT_CMD_STS) &
> + (DSI_DIRECT_CMD_STS_READ_COMPLETED |
> + DSI_DIRECT_CMD_STS_READ_COMPLETED_WITH_ERR))
> +&& --loop_counter)
> + usleep_range(loop_delay_us, (loop_delay_us * 3) / 2);
> + if (!loop_counter) {
> + dev_err(d->dev, "DSI write timeout!\n");
"DSI read timeout!" might be more apppropriate here?
> + return -ETIME;
> + }
> + } else {
> + /* Writing only */
> + while (!(readl(d->regs + DSI_DIRECT_CMD_STS) &
> + DSI_DIRECT_CMD_STS_WRITE_COMPLETED)
> +&& --loop_counter)
> + usleep_range(loop_delay_us, (loop_delay_us * 3) / 2);
> +
> + if (!loop_counter) {
> + dev_err(d->dev, "DSI write timeout!\n");
> + return -ETIME;
> + }
> }
>
> val = readl(d->regs + DSI_DIRECT_CMD_STS);
> + if (val & DSI_DIRECT_CMD_STS_READ_COMPLETED_WITH_ERR) {
> + dev_err(d->dev, "read completed with error\n");
> + writel(1, d->regs + DSI_DIRECT_CMD_RD_INIT);
> + return -EIO;
> + }
> if (val & DSI_DIRECT_CMD_STS_ACKNOWLEDGE_WITH_ERR_RECEIVED) {
> val >>= DSI_DIRECT_CMD_STS_ACK_VAL_SHIFT;
> dev_err(d->dev, "error during transmission: %04x\n",
> @@ -269,10 +290,7 @@ static ssize_
