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drm/mcde: Fix DSI transfers

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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.

Reported-by: kbuild test robot <lkp@intel.com>
Fixes: 5fc537bfd0 ("drm/mcde: Add new driver for ST-Ericsson MCDE")
Reviewed-by: Stephan Gerhold <stephan@gerhold.net>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190903170804.17053-1-linus.walleij@linaro.org
This commit is contained in:
Linus Walleij 2019-09-03 19:08:04 +02:00
parent 45d0dbd15a
commit 88537ddbbe
1 changed files with 46 additions and 22 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

68
drivers/gpu/drm/mcde/mcde_dsi.c
View File

@ -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 (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 read 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;
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_format_is_long(msg->type))
ret = 4 + txlen;
else
ret = 4;
ret = txlen;
} else {
/* OK this is a read command, get the response */
u32 rdsz;
@ -282,7 +300,13 @@ static ssize_t mcde_dsi_host_transfer(struct mipi_dsi_host *host,
rdsz = readl(d->regs + DSI_DIRECT_CMD_RD_PROPERTY);
rdsz &= DSI_DIRECT_CMD_RD_PROPERTY_RD_SIZE_MASK;
rddat = readl(d->regs + DSI_DIRECT_CMD_RDDAT);
for (i = 0; i < 4 && i < rdsz; i++)
if (rdsz < rxlen) {
dev_err(d->dev, "read error, requested %zd got %d\n",
rxlen, rdsz);
return -EIO;
}
/* FIXME: read more than 4 bytes */
for (i = 0; i < 4 && i < rxlen; i++)
rx[i] = (rddat >> (i * 8)) & 0xff;
ret = rdsz;
}