video: tegra: flesh out edid support

* read blocks in a single command instead of byte at a time
* allow reading past segment 0 (edid > 256 bytes)
* handle mutiple extention blocks
* add debugfs file for reading edid

Change-Id: Iec8182cdbccdaa2142e4bbc892202d2e8d73c23b
Signed-off-by: Erik Gilling <konkers@android.com>

2 files changed, 182 insertions, 21 deletions

diff --git a/drivers/video/tegra/dc/edid.c b/drivers/video/tegra/dc/edid.c
index 0b0b1a760a4e..812a0087a96d 100644
--- a/drivers/video/tegra/dc/edid.c
+++ b/drivers/video/tegra/dc/edid.c
@@ -15,31 +15,181 @@
  *
  */
 
-#include <linux/i2c.h>
+#define DEBUG
+
+#include <linux/debugfs.h>
 #include <linux/fb.h>
+#include <linux/i2c.h>
+#include <linux/seq_file.h>
+#include <linux/vmalloc.h>
 
 #include "edid.h"
 
+struct tegra_edid {
+	struct i2c_client	*client;
+	struct i2c_board_info	info;
+	int			bus;
+
+	u8			*data;
+	unsigned		len;
+};
+
+#if defined(DEBUG) || defined(CONFIG_DEBUG_FS)
+static int tegra_edid_show(struct seq_file *s, void *unused)
+{
+	struct tegra_edid *edid = s->private;
+	int i;
+
+	for (i = 0; i < edid->len; i++) {
+		if (i % 16 == 0)
+			seq_printf(s, "edid[%03x] =", i);
+
+		seq_printf(s, " %02x", edid->data[i]);
+
+		if (i % 16 == 15)
+			seq_printf(s, "\n");
+	}
+
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_DEBUG_FS
+static int tegra_edid_debug_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, tegra_edid_show, inode->i_private);
+}
+
+static const struct file_operations tegra_edid_debug_fops = {
+	.open		= tegra_edid_debug_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+void tegra_edid_debug_add(struct tegra_edid *edid)
+{
+	char name[] = "edidX";
+
+	snprintf(name, sizeof(name), "edid%1d", edid->bus);
+	debugfs_create_file(name, S_IRUGO, NULL, edid, &tegra_edid_debug_fops);
+}
+#else
+void tegra_edid_debug_add(struct tegra_edid *edid)
+{
+}
+#endif
+
+#ifdef DEBUG
+static char tegra_edid_dump_buff[16 * 1024];
+
+static void tegra_edid_dump(struct tegra_edid *edid)
+{
+	struct seq_file s;
+	int i;
+	char c;
+
+	memset(&s, 0x0, sizeof(s));
+
+	s.buf = tegra_edid_dump_buff;
+	s.size = sizeof(tegra_edid_dump_buff);
+	s.private = edid;
+
+	tegra_edid_show(&s, NULL);
+
+	i = 0;
+	while (i < s.count ) {
+		if ((s.count - i) > 256) {
+			c = s.buf[i + 256];
+			s.buf[i + 256] = 0;
+			printk("%s", s.buf + i);
+			s.buf[i + 256] = c;
+		} else {
+			printk("%s", s.buf + i);
+		}
+		i += 256;
+	}
+}
+#else
+static void tegra_edid_dump(struct tegra_edid *edid)
+{
+}
+#endif
+
+int tegra_edid_read_block(struct tegra_edid *edid, int block, u8 *data)
+{
+	u8 block_buf[] = {block >> 1};
+	u8 cmd_buf[] = {(block & 0x1) * 128};
+	int status;
+	struct i2c_msg msg[] = {
+		{
+			.addr = 0x30,
+			.flags = 0,
+			.len = 1,
+			.buf = block_buf,
+		},
+		{
+			.addr = 0x50,
+			.flags = 0,
+			.len = 1,
+			.buf = cmd_buf,
+		},
+		{
+			.addr = 0x50,
+			.flags = I2C_M_RD,
+			.len = 128,
+			.buf = data,
+		}};
+	struct i2c_msg *m;
+	int msg_len;
+
+	if (block > 1) {
+		msg_len = 3;
+		m = msg;
+	} else {
+		msg_len = 2;
+		m = &msg[1];
+	}
+
+	status = i2c_transfer(edid->client->adapter, m, msg_len);
+
+	if (status < 0)
+		return status;
+
+	if (status != msg_len)
+		return -EIO;
+
+	return 0;
+}
+
+
 int tegra_edid_get_monspecs(struct tegra_edid *edid, struct fb_monspecs *specs)
 {
-	u8 data[256];
 	int i;
 	int ret;
+	int extension_blocks;
+
+	ret = tegra_edid_read_block(edid, 0, edid->data);
+
+	memset(specs, 0x0, sizeof(struct fb_monspecs));
+	fb_edid_to_monspecs(edid->data, specs);
+	if (specs->modedb == NULL)
+		return -EINVAL;
+
+	extension_blocks = edid->data[0x7e];
 
-	for (i = 0; i < 256; i++) {
-		ret = i2c_smbus_read_byte_data(edid->client, i);
+	for (i = 1; i <= extension_blocks; i++) {
+		ret = tegra_edid_read_block(edid, i, edid->data + i * 128);
 		if (ret < 0)
 			break;
 
-		data[i] = ret;
+		if (edid->data[i * 128] == 0x2)
+			fb_edid_add_monspecs(edid->data + i * 128, specs);
 	}
 
-	if (i != 128 && i != 256)
-		return ret;
+	edid->len = i * 128;
 
-	fb_edid_to_monspecs(data, specs);
-	if (i == 256)
-		fb_edid_add_monspecs(data + 128, specs);
+	tegra_edid_dump(edid);
 
 	return 0;
 }
@@ -48,36 +198,53 @@ struct tegra_edid *tegra_edid_create(int bus)
 {
 	struct tegra_edid *edid;
 	struct i2c_adapter *adapter;
+	int err;
 
 	edid = kzalloc(sizeof(struct tegra_edid), GFP_KERNEL);
 	if (!edid)
 		return ERR_PTR(-ENOMEM);
 
+	edid->data = vmalloc(SZ_32K);
+	if (!edid->data) {
+		err = -ENOMEM;
+		goto free_edid;
+	}
 	strlcpy(edid->info.type, "tegra_edid", sizeof(edid->info.type));
+	edid->bus = bus;
 	edid->info.addr = 0x50;
 	edid->info.platform_data = edid;
-	init_waitqueue_head(&edid->wq);
 
 	adapter = i2c_get_adapter(bus);
 	if (!adapter) {
 		pr_err("can't get adpater for bus %d\n", bus);
-		return NULL;
+		err = -EBUSY;
+		goto free_edid;
 	}
-	edid->client = i2c_new_device(adapter, &edid->info);
 
+	edid->client = i2c_new_device(adapter, &edid->info);
 	i2c_put_adapter(adapter);
 
 	if (!edid->client) {
 		pr_err("can't create new device\n");
-		return NULL;
+		err = -EBUSY;
+		goto free_edid;
 	}
 
+	tegra_edid_debug_add(edid);
+
 	return edid;
+
+free_edid:
+	vfree(edid->data);
+	kfree(edid);
+
+	return ERR_PTR(err);
 }
 
 void tegra_edid_destroy(struct tegra_edid *edid)
 {
 	i2c_release_client(edid->client);
+	vfree(edid->data);
 	kfree(edid);
 }
 
diff --git a/drivers/video/tegra/dc/edid.h b/drivers/video/tegra/dc/edid.h
index eb78abb7e7d8..821da90a8b4f 100644
--- a/drivers/video/tegra/dc/edid.h
+++ b/drivers/video/tegra/dc/edid.h
@@ -21,13 +21,7 @@
 #include <linux/i2c.h>
 #include <linux/wait.h>
 
-struct tegra_edid {
-	struct i2c_client	*client;
-	struct i2c_board_info	info;
-
-	int			probed;
-	wait_queue_head_t	wq;
-};
+struct tegra_edid;
 
 struct tegra_edid *tegra_edid_create(int bus);
 void tegra_edid_destroy(struct tegra_edid *edid);