phy: ti: tusb1210: Improve ulpi_read()/_write() error checking

ulpi_read() and ulpi_write() calls can fail. Add wrapper functions to log
errors when this happens and add error checking to the read + write of
the phy parameters from the TUSB1210_VENDOR_SPECIFIC2 register.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20220213130524.18748-7-hdegoede@redhat.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>

diff --git a/drivers/phy/ti/phy-tusb1210.c b/drivers/phy/ti/phy-tusb1210.c
index 15c1c79e5c294dc66ab551cfad9fc72732289889..bf7793afdc840f8f83dbb4e2ad3b238bd93f09ae 100644 (file)
--- a/drivers/phy/ti/phy-tusb1210.c
+++ b/drivers/phy/ti/phy-tusb1210.c
@@ -26,6 +26,33 @@ struct tusb1210 {
        u8 vendor_specific2;
 };
 
+static int tusb1210_ulpi_write(struct tusb1210 *tusb, u8 reg, u8 val)
+{
+       int ret;
+
+       ret = ulpi_write(tusb->ulpi, reg, val);
+       if (ret)
+               dev_err(&tusb->ulpi->dev, "error %d writing val 0x%02x to reg 0x%02x\n",
+                       ret, val, reg);
+
+       return ret;
+}
+
+static int tusb1210_ulpi_read(struct tusb1210 *tusb, u8 reg, u8 *val)
+{
+       int ret;
+
+       ret = ulpi_read(tusb->ulpi, reg);
+       if (ret >= 0) {
+               *val = ret;
+               ret = 0;
+       } else {
+               dev_err(&tusb->ulpi->dev, "error %d reading reg 0x%02x\n", ret, reg);
+       }
+
+       return ret;
+}
+
 static int tusb1210_power_on(struct phy *phy)
 {
        struct tusb1210 *tusb = phy_get_drvdata(phy);
@@ -35,8 +62,8 @@ static int tusb1210_power_on(struct phy *phy)
 
        /* Restore the optional eye diagram optimization value */
        if (tusb->vendor_specific2)
-               ulpi_write(tusb->ulpi, TUSB1210_VENDOR_SPECIFIC2,
-                          tusb->vendor_specific2);
+               return tusb1210_ulpi_write(tusb, TUSB1210_VENDOR_SPECIFIC2,
+                                          tusb->vendor_specific2);
 
        return 0;
 }
@@ -55,33 +82,34 @@ static int tusb1210_set_mode(struct phy *phy, enum phy_mode mode, int submode)
 {
        struct tusb1210 *tusb = phy_get_drvdata(phy);
        int ret;
+       u8 reg;
 
-       ret = ulpi_read(tusb->ulpi, ULPI_OTG_CTRL);
+       ret = tusb1210_ulpi_read(tusb, ULPI_OTG_CTRL, &reg);
        if (ret < 0)
                return ret;
 
        switch (mode) {
        case PHY_MODE_USB_HOST:
-               ret |= (ULPI_OTG_CTRL_DRVVBUS_EXT
+               reg |= (ULPI_OTG_CTRL_DRVVBUS_EXT
                        | ULPI_OTG_CTRL_ID_PULLUP
                        | ULPI_OTG_CTRL_DP_PULLDOWN
                        | ULPI_OTG_CTRL_DM_PULLDOWN);
-               ulpi_write(tusb->ulpi, ULPI_OTG_CTRL, ret);
-               ret |= ULPI_OTG_CTRL_DRVVBUS;
+               tusb1210_ulpi_write(tusb, ULPI_OTG_CTRL, reg);
+               reg |= ULPI_OTG_CTRL_DRVVBUS;
                break;
        case PHY_MODE_USB_DEVICE:
-               ret &= ~(ULPI_OTG_CTRL_DRVVBUS
+               reg &= ~(ULPI_OTG_CTRL_DRVVBUS
                         | ULPI_OTG_CTRL_DP_PULLDOWN
                         | ULPI_OTG_CTRL_DM_PULLDOWN);
-               ulpi_write(tusb->ulpi, ULPI_OTG_CTRL, ret);
-               ret &= ~ULPI_OTG_CTRL_DRVVBUS_EXT;
+               tusb1210_ulpi_write(tusb, ULPI_OTG_CTRL, reg);
+               reg &= ~ULPI_OTG_CTRL_DRVVBUS_EXT;
                break;
        default:
                /* nothing */
                return 0;
        }
 
-       return ulpi_write(tusb->ulpi, ULPI_OTG_CTRL, ret);
+       return tusb1210_ulpi_write(tusb, ULPI_OTG_CTRL, reg);
 }
 
 static const struct phy_ops phy_ops = {
@@ -95,11 +123,14 @@ static int tusb1210_probe(struct ulpi *ulpi)
 {
        struct tusb1210 *tusb;
        u8 val, reg;
+       int ret;
 
        tusb = devm_kzalloc(&ulpi->dev, sizeof(*tusb), GFP_KERNEL);
        if (!tusb)
                return -ENOMEM;
 
+       tusb->ulpi = ulpi;
+
        tusb->gpio_reset = devm_gpiod_get_optional(&ulpi->dev, "reset",
                                                   GPIOD_OUT_LOW);
        if (IS_ERR(tusb->gpio_reset))
@@ -119,7 +150,9 @@ static int tusb1210_probe(struct ulpi *ulpi)
         * diagram optimization and DP/DM swap.
         */
 
-       reg = ulpi_read(ulpi, TUSB1210_VENDOR_SPECIFIC2);
+       ret = tusb1210_ulpi_read(tusb, TUSB1210_VENDOR_SPECIFIC2, &reg);
+       if (ret)
+               return ret;
 
        /* High speed output drive strength configuration */
        if (!device_property_read_u8(&ulpi->dev, "ihstx", &val))
@@ -133,15 +166,16 @@ static int tusb1210_probe(struct ulpi *ulpi)
        if (!device_property_read_u8(&ulpi->dev, "datapolarity", &val))
                u8p_replace_bits(&reg, val, (u8)TUSB1210_VENDOR_SPECIFIC2_DP_MASK);
 
-       ulpi_write(ulpi, TUSB1210_VENDOR_SPECIFIC2, reg);
+       ret = tusb1210_ulpi_write(tusb, TUSB1210_VENDOR_SPECIFIC2, reg);
+       if (ret)
+               return ret;
+
        tusb->vendor_specific2 = reg;
 
        tusb->phy = ulpi_phy_create(ulpi, &phy_ops);
        if (IS_ERR(tusb->phy))
                return PTR_ERR(tusb->phy);
 
-       tusb->ulpi = ulpi;
-
        phy_set_drvdata(tusb->phy, tusb);
        ulpi_set_drvdata(ulpi, tusb);
        return 0;