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FROMLIST: drm/bridge: dw_hdmi: support i2c extended read mode

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"I2C Master Interface Extended Read Mode" implements a segment
pointer-based read operation using the Special Register configuration.

This patch fix https://patchwork.kernel.org/patch/7098101/ mentioned
"The current implementation does not support "I2C Master Interface
Extended Read Mode" to read data addressed by non-zero segment
pointer, this means that if EDID has more than 1 extension blocks"

With this patch,dw-hdmi can read EDID data with 1/2/4 blocks.

(am from https://patchwork.kernel.org/patch/9586343/)

BUG=chrome-os-partner:59768
TEST=fievel can read 1/2/4 blocks EDID data

Change-Id: I086e6ea63ec69c0532be445b958ce253a7f1f3cc
Signed-off-by: Nickey Yang <nickey.yang@rock-chips.com>
Reviewed-on: https://chromium-review.googlesource.com/442308
Reviewed-by: Douglas Anderson <dianders@chromium.org>
This commit is contained in:
Nickey Yang
2017-03-09 10:56:37 +08:00
committed by Huang, Tao
parent 1eb011849f
commit 7d8946a76e
1 changed files with 24 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

38
drivers/gpu/drm/bridge/dw-hdmi.c
View File

@@ -39,6 +39,7 @@
#include "dw-hdmi-audio.h"
#define HDMI_EDID_LEN 512
#define DDC_SEGMENT_ADDR 0x30
#define RGB 0
#define YCBCR444 1
@@ -174,6 +175,7 @@ struct dw_hdmi_i2c {
u8 slave_reg;
bool is_regaddr;
bool is_segment;
};
struct dw_hdmi {
@@ -317,8 +319,12 @@ static int dw_hdmi_i2c_read(struct dw_hdmi *hdmi,
reinit_completion(&i2c->cmp);
hdmi_writeb(hdmi, i2c->slave_reg++, HDMI_I2CM_ADDRESS);
hdmi_writeb(hdmi, HDMI_I2CM_OPERATION_READ,
HDMI_I2CM_OPERATION);
if (i2c->is_segment)
hdmi_writeb(hdmi, HDMI_I2CM_OPERATION_READ_EXT,
HDMI_I2CM_OPERATION);
else
hdmi_writeb(hdmi, HDMI_I2CM_OPERATION_READ,
HDMI_I2CM_OPERATION);
stat = wait_for_completion_timeout(&i2c->cmp, HZ / 10);
if (!stat)
@@ -330,6 +336,7 @@ static int dw_hdmi_i2c_read(struct dw_hdmi *hdmi,
*buf++ = hdmi_readb(hdmi, HDMI_I2CM_DATAI);
}
i2c->is_segment = false;
return 0;
}
@@ -379,12 +386,6 @@ static int dw_hdmi_i2c_xfer(struct i2c_adapter *adap,
dev_dbg(hdmi->dev, "xfer: num: %d, addr: %#x\n", num, addr);
for (i = 0; i < num; i++) {
if (msgs[i].addr != addr) {
dev_warn(hdmi->dev,
"unsupported transfer, changed slave address\n");
return -EOPNOTSUPP;
}
if (msgs[i].len == 0) {
dev_dbg(hdmi->dev,
"unsupported transfer %d/%d, no data\n",
@@ -403,15 +404,24 @@ static int dw_hdmi_i2c_xfer(struct i2c_adapter *adap,
/* Set slave device register address on transfer */
i2c->is_regaddr = false;
/* Set segment pointer for I2C extended read mode operation */
i2c->is_segment = false;
for (i = 0; i < num; i++) {
dev_dbg(hdmi->dev, "xfer: num: %d/%d, len: %d, flags: %#x\n",
i + 1, num, msgs[i].len, msgs[i].flags);
if (msgs[i].flags & I2C_M_RD)
ret = dw_hdmi_i2c_read(hdmi, msgs[i].buf, msgs[i].len);
else
ret = dw_hdmi_i2c_write(hdmi, msgs[i].buf, msgs[i].len);
if (msgs[i].addr == DDC_SEGMENT_ADDR && msgs[i].len == 1) {
i2c->is_segment = true;
hdmi_writeb(hdmi, DDC_SEGMENT_ADDR, HDMI_I2CM_SEGADDR);
hdmi_writeb(hdmi, *msgs[i].buf, HDMI_I2CM_SEGPTR);
} else {
if (msgs[i].flags & I2C_M_RD)
ret = dw_hdmi_i2c_read(hdmi, msgs[i].buf,
msgs[i].len);
else
ret = dw_hdmi_i2c_write(hdmi, msgs[i].buf,
msgs[i].len);
}
if (ret < 0)
break;
}