drm/i915: add support for dvo Chrontel 7010B

This patch add dvo detection for the Chrontel 7010B on some old hardware.

References: https://bugzilla.kernel.org/show_bug.cgi?id=55101
Signed-off-by: Braggle <braggle at free.fr>
[danvet: Fix up whitespace mangling.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/dvo_ch7xxx.c

@@ -32,12 +32,14 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 #define CH7xxx_REG_DID		0x4b
 
 #define CH7011_VID		0x83 /* 7010 as well */
+#define CH7010B_VID		0x05
 #define CH7009A_VID		0x84
 #define CH7009B_VID		0x85
 #define CH7301_VID		0x95
 
 #define CH7xxx_VID		0x84
 #define CH7xxx_DID		0x17
+#define CH7010_DID		0x16
 
 #define CH7xxx_NUM_REGS		0x4c
 
@@ -87,11 +89,20 @@ static struct ch7xxx_id_struct {
 	char *name;
 } ch7xxx_ids[] = {
 	{ CH7011_VID, "CH7011" },
+	{ CH7010B_VID, "CH7010B" },
 	{ CH7009A_VID, "CH7009A" },
 	{ CH7009B_VID, "CH7009B" },
 	{ CH7301_VID, "CH7301" },
 };
 
+static struct ch7xxx_did_struct {
+	uint8_t did;
+	char *name;
+} ch7xxx_dids[] = {
+	{ CH7xxx_DID, "CH7XXX" },
+	{ CH7010_DID, "CH7010B" },
+};
+
 struct ch7xxx_priv {
 	bool quiet;
 };
@@ -108,6 +119,18 @@ static char *ch7xxx_get_id(uint8_t vid)
 	return NULL;
 }
 
+static char *ch7xxx_get_did(uint8_t did)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(ch7xxx_dids); i++) {
+		if (ch7xxx_dids[i].did == did)
+			return ch7xxx_dids[i].name;
+	}
+
+	return NULL;
+}
+
 /** Reads an 8 bit register */
 static bool ch7xxx_readb(struct intel_dvo_device *dvo, int addr, uint8_t *ch)
 {
@@ -179,7 +202,7 @@ static bool ch7xxx_init(struct intel_dvo_device *dvo,
 	/* this will detect the CH7xxx chip on the specified i2c bus */
 	struct ch7xxx_priv *ch7xxx;
 	uint8_t vendor, device;
-	char *name;
+	char *name, *devid;
 
 	ch7xxx = kzalloc(sizeof(struct ch7xxx_priv), GFP_KERNEL);
 	if (ch7xxx == NULL)
@@ -204,7 +227,8 @@ static bool ch7xxx_init(struct intel_dvo_device *dvo,
 	if (!ch7xxx_readb(dvo, CH7xxx_REG_DID, &device))
 		goto out;
 
-	if (device != CH7xxx_DID) {
+	devid = ch7xxx_get_did(device);
+	if (!devid) {
 		DRM_DEBUG_KMS("ch7xxx not detected; got 0x%02x from %s "
 				"slave %d.\n",
 			  vendor, adapter->name, dvo->slave_addr);

drivers/gpu/drm/i915/intel_dvo.c

@@ -53,6 +53,13 @@ static const struct intel_dvo_device intel_dvo_devices[] = {
 		.slave_addr = CH7xxx_ADDR,
 		.dev_ops = &ch7xxx_ops,
 	},
+	{
+		.type = INTEL_DVO_CHIP_TMDS,
+		.name = "ch7xxx",
+		.dvo_reg = DVOC,
+		.slave_addr = 0x75, /* For some ch7010 */
+		.dev_ops = &ch7xxx_ops,
+	},
 	{
 		.type = INTEL_DVO_CHIP_LVDS,
 		.name = "ivch",