msm: mdss: dp: add configuration sysfs node

Add node named 'config' to let the user modules know
about the supported DisplayPort configurations. On
every cable connection, user modules can read this sysfs
node to configure accordingly. This sysfs node can also
be used to force a test pattern on the DP interface using
the following syntax:

echo "bpp=<bpp> pattern_type=<pattern>" > /sys/class/graphics/<fbi>/config
where
   * bpp = [0/18/24/30]
   * pattern_type = [0/1/2/3]

CRs-Fixed: 1109812
Change-Id: Ia2890e8c8e6214d4a1532f081d7c906484c99a03
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>
Signed-off-by: Aravind Venkateswaran <aravindh@codeaurora.org>

drivers/video/fbdev/msm/mdss_dp.c

@@ -1037,7 +1037,7 @@ static u32 mdss_dp_get_bpp(struct mdss_dp_drv_pdata *dp)
 	 * For test pattern, the test data has the bit depth per color
 	 * component. Otherwise, set it based on EDID.
 	 */
-	if (mdss_dp_is_video_pattern_requested(dp))
+	if (dp->override_config || mdss_dp_is_video_pattern_requested(dp))
 		bit_depth = dp->test_data.test_bit_depth;
 	else
 		bit_depth = dp->edid.color_depth;
@@ -2202,6 +2202,111 @@ static ssize_t mdss_dp_rda_hpd(struct device *dev,
 	return ret;
 }
 
+static int mdss_dp_parse_config_value(char const *buf, char const *name,
+	u32 *val)
+{
+	int ret = 0;
+	char *buf1;
+	char *token;
+
+	buf1 = strnstr(buf, name, PAGE_SIZE);
+	if (buf1) {
+		buf1 = buf1 + strlen(name);
+		token = strsep(&buf1, " ");
+		ret = kstrtou32(token, 10, val);
+		if (ret) {
+			pr_err("kstrtoint failed. ret=%d\n", (int)ret);
+			goto end;
+		}
+		pr_debug("parsed %s(%d)\n", name, *val);
+	} else {
+		ret = -EINVAL;
+	}
+
+end:
+	return ret;
+}
+
+static ssize_t mdss_dp_wta_config(struct device *dev,
+	struct device_attribute *attr, const char *buf, size_t count)
+{
+	u32 val;
+	u32 bit_depth;
+	int ret;
+	char const *bpp_key = "bpp=";
+	char const *pattern_type_key = "pattern_type=";
+	struct mdss_dp_drv_pdata *dp = mdss_dp_get_drvdata(dev);
+
+	if (!dp) {
+		pr_err("invalid data\n");
+		ret = -EINVAL;
+		goto end;
+	}
+
+	ret = mdss_dp_parse_config_value(buf, bpp_key, &val);
+	if (ret) {
+		pr_debug("%s config not found\n", bpp_key);
+		goto pattern_type;
+	}
+
+	bit_depth = mdss_dp_bpp_to_test_bit_depth(val);
+	if (!mdss_dp_is_test_bit_depth_valid(bit_depth)) {
+		pr_err("invalid bpp = %d\n", val);
+	} else {
+		dp->test_data.test_bit_depth = bit_depth;
+		if (val != 0)
+			dp->override_config = true;
+		else
+			dp->override_config = false;
+		pr_debug("bpp=%d, test_bit_depth=%d\n", val,
+			dp->test_data.test_bit_depth);
+	}
+
+pattern_type:
+	ret = mdss_dp_parse_config_value(buf, pattern_type_key, &val);
+	if (ret) {
+		pr_debug("%s config not found\n", pattern_type_key);
+		goto end;
+	}
+
+	if (!mdss_dp_is_test_video_pattern_valid(val)) {
+		pr_err("invalid test video pattern = %d\n", val);
+	} else {
+		dp->test_data.test_video_pattern = val;
+		pr_debug("test_video_pattern=%d (%s)\n",
+			dp->test_data.test_video_pattern,
+			mdss_dp_test_video_pattern_to_string(
+				dp->test_data.test_video_pattern));
+	}
+
+end:
+	return count;
+}
+
+static ssize_t mdss_dp_rda_config(struct device *dev,
+	struct device_attribute *attr, char *buf)
+{
+	ssize_t ret;
+	u32 bpp;
+	struct mdss_dp_drv_pdata *dp = mdss_dp_get_drvdata(dev);
+
+	if (!dp) {
+		pr_err("invalid input\n");
+		return -EINVAL;
+	}
+
+	bpp = mdss_dp_get_bpp(dp);
+	ret = snprintf(buf, PAGE_SIZE, "bpp=%d\npattern_type=%d\n",
+		bpp, dp->test_data.test_video_pattern);
+
+	pr_debug("bpp: %d pattern_type=%d (%s)\n",
+		bpp, dp->test_data.test_video_pattern,
+		mdss_dp_test_video_pattern_to_string(
+			dp->test_data.test_video_pattern));
+
+	return ret;
+}
+
 static DEVICE_ATTR(connected, S_IRUGO, mdss_dp_rda_connected, NULL);
 static DEVICE_ATTR(s3d_mode, S_IRUGO | S_IWUSR, mdss_dp_sysfs_rda_s3d_mode,
 	mdss_dp_sysfs_wta_s3d_mode);
@@ -2209,13 +2314,15 @@ static DEVICE_ATTR(hpd, S_IRUGO | S_IWUSR, mdss_dp_rda_hpd,
 	mdss_dp_wta_hpd);
 static DEVICE_ATTR(psm, S_IRUGO | S_IWUSR, mdss_dp_rda_psm,
 	mdss_dp_wta_psm);
-
+static DEVICE_ATTR(config, S_IRUGO | S_IWUSR, mdss_dp_rda_config,
+	mdss_dp_wta_config);
 
 static struct attribute *mdss_dp_fs_attrs[] = {
 	&dev_attr_connected.attr,
 	&dev_attr_s3d_mode.attr,
 	&dev_attr_hpd.attr,
 	&dev_attr_psm.attr,
+	&dev_attr_config.attr,
 	NULL,
 };
 

drivers/video/fbdev/msm/mdss_dp.h

@@ -443,6 +443,7 @@ struct mdss_dp_drv_pdata {
 	struct dss_io_data hdcp_io;
 	int base_size;
 	unsigned char *mmss_cc_base;
+	bool override_config;
 	u32 mask1;
 	u32 mask2;