[PATCH V5 4/5] drm/bridge: it66121: Use vid/pid to detect the type of chip

[Nishanth Menon <nm@ti.com>]

The driver knows exactly which version of the chip is present since
the vid/pid is used to enforce a compatibility. Given that some
devices like IT66121 has potentially been replaced with IT66122 mid
production for many platforms, it makes no sense to use the vid/pid
as an enforcement for compatibility. Instead, detect the ID of the
actual chip in use by matching the corresponding vid/pid and drop the
compatible specific lookup table.

Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Andrew Davis <afd@ti.com>
---
Changes since V4:
- Switched to ARRAY_SIZE, Dropped the null entry
- Picked up Andrew's Reviewed-by

V4: https://lore.kernel.org/all/20250819130807.3322536-5-nm@ti.com/
V3: https://lore.kernel.org/all/20250815034105.1276548-4-nm@ti.com/
V2: https://lore.kernel.org/all/20250813204106.580141-3-nm@ti.com/

 drivers/gpu/drm/bridge/ite-it66121.c | 58 ++++++++++++++--------------
 1 file changed, 29 insertions(+), 29 deletions(-)

diff --git a/drivers/gpu/drm/bridge/ite-it66121.c b/drivers/gpu/drm/bridge/ite-it66121.c
index cd74f3966560..1b2ef774c770 100644
--- a/drivers/gpu/drm/bridge/ite-it66121.c
+++ b/drivers/gpu/drm/bridge/ite-it66121.c
@@ -312,7 +312,7 @@ struct it66121_ctx {
 		u8 swl;
 		bool auto_cts;
 	} audio;
-	const struct it66121_chip_info *info;
+	enum chip_id id;
 };
 
 static const struct regmap_range_cfg it66121_regmap_banks[] = {
@@ -402,7 +402,7 @@ static int it66121_configure_afe(struct it66121_ctx *ctx,
 		if (ret)
 			return ret;
 
-		if (ctx->info->id == ID_IT66121) {
+		if (ctx->id == ID_IT66121) {
 			ret = regmap_write_bits(ctx->regmap, IT66121_AFE_IP_REG,
 						IT66121_AFE_IP_EC1, 0);
 			if (ret)
@@ -428,7 +428,7 @@ static int it66121_configure_afe(struct it66121_ctx *ctx,
 		if (ret)
 			return ret;
 
-		if (ctx->info->id == ID_IT66121) {
+		if (ctx->id == ID_IT66121) {
 			ret = regmap_write_bits(ctx->regmap, IT66121_AFE_IP_REG,
 						IT66121_AFE_IP_EC1,
 						IT66121_AFE_IP_EC1);
@@ -449,7 +449,7 @@ static int it66121_configure_afe(struct it66121_ctx *ctx,
 	if (ret)
 		return ret;
 
-	if (ctx->info->id == ID_IT6610) {
+	if (ctx->id == ID_IT6610) {
 		ret = regmap_write_bits(ctx->regmap, IT66121_AFE_XP_REG,
 					IT6610_AFE_XP_BYPASS,
 					IT6610_AFE_XP_BYPASS);
@@ -599,7 +599,7 @@ static int it66121_bridge_attach(struct drm_bridge *bridge,
 	if (ret)
 		return ret;
 
-	if (ctx->info->id == ID_IT66121) {
+	if (ctx->id == ID_IT66121) {
 		ret = regmap_write_bits(ctx->regmap, IT66121_CLK_BANK_REG,
 					IT66121_CLK_BANK_PWROFF_RCLK, 0);
 		if (ret)
@@ -748,7 +748,7 @@ static int it66121_bridge_check(struct drm_bridge *bridge,
 {
 	struct it66121_ctx *ctx = container_of(bridge, struct it66121_ctx, bridge);
 
-	if (ctx->info->id == ID_IT6610) {
+	if (ctx->id == ID_IT6610) {
 		/* The IT6610 only supports these settings */
 		bridge_state->input_bus_cfg.flags |= DRM_BUS_FLAG_DE_HIGH |
 			DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE;
@@ -802,7 +802,7 @@ void it66121_bridge_mode_set(struct drm_bridge *bridge,
 	if (regmap_write(ctx->regmap, IT66121_HDMI_MODE_REG, IT66121_HDMI_MODE_HDMI))
 		goto unlock;
 
-	if (ctx->info->id == ID_IT66121 &&
+	if (ctx->id == ID_IT66121 &&
 	    regmap_write_bits(ctx->regmap, IT66121_CLK_BANK_REG,
 			      IT66121_CLK_BANK_PWROFF_TXCLK,
 			      IT66121_CLK_BANK_PWROFF_TXCLK)) {
@@ -815,7 +815,7 @@ void it66121_bridge_mode_set(struct drm_bridge *bridge,
 	if (it66121_configure_afe(ctx, adjusted_mode))
 		goto unlock;
 
-	if (ctx->info->id == ID_IT66121 &&
+	if (ctx->id == ID_IT66121 &&
 	    regmap_write_bits(ctx->regmap, IT66121_CLK_BANK_REG,
 			      IT66121_CLK_BANK_PWROFF_TXCLK, 0)) {
 		goto unlock;
@@ -1498,13 +1498,19 @@ static const char * const it66121_supplies[] = {
 	"vcn33", "vcn18", "vrf12"
 };
 
+static const struct it66121_chip_info it66xx_chip_info[] = {
+	{.id = ID_IT6610, .vid = 0xca00, .pid = 0x0611 },
+	{.id = ID_IT66121, .vid = 0x4954, .pid = 0x0612 },
+};
+
 static int it66121_probe(struct i2c_client *client)
 {
 	u32 revision_id, vendor_ids[2] = { 0 }, device_ids[2] = { 0 };
 	struct device_node *ep;
-	int ret;
+	int ret, i;
 	struct it66121_ctx *ctx;
 	struct device *dev = &client->dev;
+	const struct it66121_chip_info *chip_info;
 
 	if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) {
 		dev_err(dev, "I2C check functionality failed.\n");
@@ -1522,7 +1528,6 @@ static int it66121_probe(struct i2c_client *client)
 
 	ctx->dev = dev;
 	ctx->client = client;
-	ctx->info = i2c_get_match_data(client);
 
 	of_property_read_u32(ep, "bus-width", &ctx->bus_width);
 	of_node_put(ep);
@@ -1568,11 +1573,18 @@ static int it66121_probe(struct i2c_client *client)
 	revision_id = FIELD_GET(IT66121_REVISION_MASK, device_ids[1]);
 	device_ids[1] &= IT66121_DEVICE_ID1_MASK;
 
-	if ((vendor_ids[1] << 8 | vendor_ids[0]) != ctx->info->vid ||
-	    (device_ids[1] << 8 | device_ids[0]) != ctx->info->pid) {
-		return -ENODEV;
+	for (i = 0; i < ARRAY_SIZE(it66xx_chip_info); i++) {
+		chip_info = &it66xx_chip_info[i];
+		if ((vendor_ids[1] << 8 | vendor_ids[0]) == chip_info->vid &&
+		    (device_ids[1] << 8 | device_ids[0]) == chip_info->pid) {
+			ctx->id = chip_info->id;
+			break;
+		}
 	}
 
+	if (i == ARRAY_SIZE(it66xx_chip_info))
+		return -ENODEV;
+
 	ctx->bridge.of_node = dev->of_node;
 	ctx->bridge.type = DRM_MODE_CONNECTOR_HDMIA;
 	ctx->bridge.ops = DRM_BRIDGE_OP_DETECT | DRM_BRIDGE_OP_EDID;
@@ -1606,28 +1618,16 @@ static void it66121_remove(struct i2c_client *client)
 	mutex_destroy(&ctx->lock);
 }
 
-static const struct it66121_chip_info it66121_chip_info = {
-	.id = ID_IT66121,
-	.vid = 0x4954,
-	.pid = 0x0612,
-};
-
-static const struct it66121_chip_info it6610_chip_info = {
-	.id = ID_IT6610,
-	.vid = 0xca00,
-	.pid = 0x0611,
-};
-
 static const struct of_device_id it66121_dt_match[] = {
-	{ .compatible = "ite,it6610", &it6610_chip_info },
-	{ .compatible = "ite,it66121", &it66121_chip_info },
+	{ .compatible = "ite,it6610" },
+	{ .compatible = "ite,it66121" },
 	{ }
 };
 MODULE_DEVICE_TABLE(of, it66121_dt_match);
 
 static const struct i2c_device_id it66121_id[] = {
-	{ "it6610", (kernel_ulong_t)&it6610_chip_info },
-	{ "it66121", (kernel_ulong_t)&it66121_chip_info },
+	{ .name = "it6610" },
+	{ .name = "it66121" },
 	{ }
 };
 MODULE_DEVICE_TABLE(i2c, it66121_id);
-- 
2.47.0