msm: mdss: expose MDP capabilities through sysfs on 8x10

Currently, MDP capabilities are exposed to the client via
a dedicated ioctl.  As more capabilities are added, it becomes
difficult to have to extend and maintain header file compatibility.
This change is to add a sysfs node which can be used to get the
MDP capabilities.

Change-Id: I9eb2e5546f708eb3f46c61f9abe4f25f23cd64aa
Signed-off-by: Xiaoming Zhou <zhoux@codeaurora.org>

3 files changed, 56 insertions, 0 deletions

diff --git a/drivers/video/fbdev/msm/mdp3.c b/drivers/video/fbdev/msm/mdp3.c
index 74a91d1dce90..da3c5e04ec3c 100644
--- a/drivers/video/fbdev/msm/mdp3.c
+++ b/drivers/video/fbdev/msm/mdp3.c
@@ -1936,6 +1936,53 @@ static void mdp3_dma_underrun_intr_handler(int type, void *arg)
 			mdp3_res->underrun_cnt);
 }
 
+static ssize_t mdp3_show_capabilities(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	size_t len = PAGE_SIZE;
+	int cnt = 0;
+
+#define SPRINT(fmt, ...) \
+		(cnt += scnprintf(buf + cnt, len - cnt, fmt, ##__VA_ARGS__))
+
+	SPRINT("mdp_version=3\n");
+	SPRINT("hw_rev=%d\n", 304);
+	SPRINT("dma_pipes=%d\n", 1);
+	SPRINT("\n");
+
+	return cnt;
+}
+
+static DEVICE_ATTR(caps, S_IRUGO, mdp3_show_capabilities, NULL);
+
+static struct attribute *mdp3_fs_attrs[] = {
+	&dev_attr_caps.attr,
+	NULL
+};
+
+static struct attribute_group mdp3_fs_attr_group = {
+	.attrs = mdp3_fs_attrs
+};
+
+static int mdp3_register_sysfs(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	int rc;
+
+	rc = sysfs_create_group(&dev->kobj, &mdp3_fs_attr_group);
+
+	return rc;
+}
+
+int mdp3_create_sysfs_link(struct device *dev)
+{
+	int rc;
+	rc = sysfs_create_link_nowarn(&dev->kobj,
+			&mdp3_res->pdev->dev.kobj, "mdp");
+
+	return rc;
+}
+
 static int mdp3_probe(struct platform_device *pdev)
 {
 	int rc;
@@ -1994,6 +2041,10 @@ static int mdp3_probe(struct platform_device *pdev)
 		goto probe_done;
 	}
 
+	rc = mdp3_register_sysfs(pdev);
+	if (rc)
+		pr_err("unable to register mdp sysfs nodes\n");
+
 	rc = mdss_fb_register_mdp_instance(&mdp3_interface);
 	if (rc)
 		pr_err("unable to register mdp instance\n");
diff --git a/drivers/video/fbdev/msm/mdp3.h b/drivers/video/fbdev/msm/mdp3.h
index c7ad8d367066..7c110fa5be7e 100644
--- a/drivers/video/fbdev/msm/mdp3.h
+++ b/drivers/video/fbdev/msm/mdp3.h
@@ -188,6 +188,7 @@ int mdp3_iommu_is_attached(int client);
 void mdp3_free(void);
 int mdp3_parse_dt_splash(struct msm_fb_data_type *mfd);
 void mdp3_release_splash_memory(void);
+int mdp3_create_sysfs_link(struct device *dev);
 
 #define MDP3_REG_WRITE(addr, val) writel_relaxed(val, mdp3_res->mdp_base + addr)
 #define MDP3_REG_READ(addr) readl_relaxed(mdp3_res->mdp_base + addr)
diff --git a/drivers/video/fbdev/msm/mdp3_ctrl.c b/drivers/video/fbdev/msm/mdp3_ctrl.c
index dff9b05426fe..c79a17198fd0 100644
--- a/drivers/video/fbdev/msm/mdp3_ctrl.c
+++ b/drivers/video/fbdev/msm/mdp3_ctrl.c
@@ -1555,6 +1555,10 @@ int mdp3_ctrl_init(struct msm_fb_data_type *mfd)
 		goto init_done;
 	}
 
+	rc = mdp3_create_sysfs_link(dev);
+	if (rc)
+		pr_warn("problem creating link to mdp sysfs\n");
+
 	kobject_uevent(&dev->kobj, KOBJ_ADD);
 	pr_debug("vsync kobject_uevent(KOBJ_ADD)\n");