DEBUG: phy: nxp-ptn3222: Add debug register reads

This allows checking if the defined i2c bus is actually correct, since the
driver does not use the i2c register interface otherwise at the moment.

Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>

drivers/phy/Kconfig

@@ -87,6 +87,7 @@ config PHY_NXP_PTN3222
 	depends on I2C
 	depends on OF
 	select GENERIC_PHY
+	select REGMAP_I2C
 	help
 	  Enable this to support NXP PTN3222 1-port eUSB2 to USB2 Redriver.
 	  This redriver performs translation between eUSB2 and USB2 signalling

drivers/phy/phy-nxp-ptn3222.c

@@ -15,6 +15,7 @@
 
 struct ptn3222 {
 	struct i2c_client *client;
+	struct regmap *regmap;
 	struct phy *phy;
 	struct gpio_desc *reset_gpio;
 	struct regulator_bulk_data *supplies;
@@ -23,6 +24,8 @@ struct ptn3222 {
 static int ptn3222_init(struct phy *phy)
 {
 	struct ptn3222 *ptn3222 = phy_get_drvdata(phy);
+	struct device *dev = &ptn3222->client->dev;
+	unsigned int rev_id, chip_id0, chip_id1, chip_id2;
 	int ret;
 
 	ret = regulator_bulk_enable(NUM_SUPPLIES, ptn3222->supplies);
@@ -31,6 +34,32 @@ static int ptn3222_init(struct phy *phy)
 
 	gpiod_set_value_cansleep(ptn3222->reset_gpio, 0);
 
+	msleep(20);
+
+	ret = regmap_read(ptn3222->regmap, 0x13, &rev_id);
+	if (ret)
+		dev_err(dev, "failed to read 0x13: %d\n", ret);
+
+	ret = regmap_read(ptn3222->regmap, 0x14, &chip_id0);
+	if (ret)
+		dev_err(dev, "failed to read 0x14: %d\n", ret);
+
+	ret = regmap_read(ptn3222->regmap, 0x15, &chip_id1);
+	if (ret)
+		dev_err(dev, "failed to read 0x15: %d\n", ret);
+
+	ret = regmap_read(ptn3222->regmap, 0x16, &chip_id2);
+	if (ret)
+		dev_err(dev, "failed to read 0x16: %d\n", ret);
+
+	dev_info(dev, "REVISION_ID %#x CHIP_ID %#x %#x %#x\n",
+		 rev_id, chip_id0, chip_id1, chip_id2);
+
+	if (rev_id != 0xA2 || chip_id0 != 0x22 || chip_id1 != 0x32)
+		dev_err(dev, "chip id mismatch\n");
+	else
+		dev_info(dev, "chip id matches\n");
+
 	return 0;
 }
 
@@ -59,6 +88,12 @@ static const struct regulator_bulk_data ptn3222_supplies[NUM_SUPPLIES] = {
 	}
 };
 
+static const struct regmap_config ptn3222_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = 0x16,
+};
+
 static int ptn3222_probe(struct i2c_client *client)
 {
 	struct device *dev = &client->dev;
@@ -72,6 +107,11 @@ static int ptn3222_probe(struct i2c_client *client)
 
 	ptn3222->client = client;
 
+	ptn3222->regmap = devm_regmap_init_i2c(client, &ptn3222_regmap_config);
+	if (IS_ERR(ptn3222->regmap))
+		return dev_err_probe(dev, PTR_ERR(ptn3222->regmap),
+				     "unable to init regmap\n");
+
 	ptn3222->reset_gpio = devm_gpiod_get_optional(dev, "reset",
 						      GPIOD_OUT_HIGH);
 	if (IS_ERR(ptn3222->reset_gpio))