staging: dwc2: validate the value for phy_utmi_width

The HWCFG4 register stores the supported utmi width values (8, 16 or
both). This commit reads that value and validates the configured value
against that.

If no (valid) value is given, the parameter defaulted to 8 bits
previously.  However, the documentation for dwc2_core_params_struct
suggests that the default should have been 16. Also, the pci bindings
explicitely set the value to 16, so this commit changes the default to
16 bits (if supported, 8 bits otherwise).

With the default changed, the value set in pci.c is changed to -1 to
make it autodetected as well.

Signed-off-by: Matthijs Kooijman <matthijs@stdin.nl>
Acked-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/dwc2/core.c

@@ -2376,14 +2376,29 @@ int dwc2_set_param_phy_ulpi_ext_vbus(struct dwc2_hsotg *hsotg, int val)
 
 int dwc2_set_param_phy_utmi_width(struct dwc2_hsotg *hsotg, int val)
 {
+	int valid = 0;
 	int retval = 0;
 
-	if (DWC2_PARAM_TEST(val, 8, 8) && DWC2_PARAM_TEST(val, 16, 16)) {
+	switch (hsotg->hw_params.utmi_phy_data_width) {
+	case GHWCFG4_UTMI_PHY_DATA_WIDTH_8:
+		valid = (val == 8);
+		break;
+	case GHWCFG4_UTMI_PHY_DATA_WIDTH_16:
+		valid = (val == 16);
+		break;
+	case GHWCFG4_UTMI_PHY_DATA_WIDTH_8_OR_16:
+		valid = (val == 8 || val == 16);
+		break;
+	}
+
+	if (!valid) {
 		if (val >= 0) {
-			dev_err(hsotg->dev, "Wrong value for phy_utmi_width\n");
-			dev_err(hsotg->dev, "phy_utmi_width must be 8 or 16\n");
+			dev_err(hsotg->dev,
+				"%d invalid for phy_utmi_width. Check HW configuration.\n",
+				val);
 		}
-		val = 8;
+		val = (hsotg->hw_params.utmi_phy_data_width ==
+		       GHWCFG4_UTMI_PHY_DATA_WIDTH_8) ? 8 : 16;
 		dev_dbg(hsotg->dev, "Setting phy_utmi_width to %d\n", val);
 		retval = -EINVAL;
 	}
@@ -2660,6 +2675,8 @@ int dwc2_get_hwparams(struct dwc2_hsotg *hsotg)
 				  GHWCFG4_NUM_DEV_PERIO_IN_EP_SHIFT;
 	hw->dma_desc_enable = !!(hwcfg4 & GHWCFG4_DESC_DMA);
 	hw->power_optimized = !!(hwcfg4 & GHWCFG4_POWER_OPTIMIZ);
+	hw->utmi_phy_data_width = (hwcfg4 & GHWCFG4_UTMI_PHY_DATA_WIDTH_MASK) >>
+				  GHWCFG4_UTMI_PHY_DATA_WIDTH_SHIFT;
 
 	/* fifo sizes */
 	hw->host_rx_fifo_size = (grxfsiz & GRXFSIZ_DEPTH_MASK) >>
@@ -2684,6 +2701,8 @@ int dwc2_get_hwparams(struct dwc2_hsotg *hsotg)
 		hw->hs_phy_type);
 	dev_dbg(hsotg->dev, "  fs_phy_type=%d\n",
 		hw->fs_phy_type);
+	dev_dbg(hsotg->dev, "  utmi_phy_data_wdith=%d\n",
+		hw->utmi_phy_data_width);
 	dev_dbg(hsotg->dev, "  num_dev_ep=%d\n",
 		hw->num_dev_ep);
 	dev_dbg(hsotg->dev, "  num_dev_perio_in_ep=%d\n",

drivers/staging/dwc2/core.h

@@ -239,6 +239,10 @@ struct dwc2_core_params {
  *                       2 - FS pins shared with UTMI+ pins
  *                       3 - FS pins shared with ULPI pins
  * @total_fifo_size:    Total internal RAM for FIFOs (bytes)
+ * @utmi_phy_data_width UTMI+ PHY data width
+ *                       0 - 8 bits
+ *                       1 - 16 bits
+ *                       2 - 8 or 16 bits
  * @snpsid:             Value from SNPSID register
  */
 struct dwc2_hw_params {
@@ -263,6 +267,7 @@ struct dwc2_hw_params {
 	unsigned num_dev_perio_in_ep:4;
 	unsigned total_fifo_size:16;
 	unsigned power_optimized:1;
+	unsigned utmi_phy_data_width:2;
 	u32 snpsid;
 };
 

drivers/staging/dwc2/hw.h

@@ -302,6 +302,9 @@
 #define GHWCFG4_NUM_DEV_MODE_CTRL_EP_SHIFT	16
 #define GHWCFG4_UTMI_PHY_DATA_WIDTH_MASK	(0x3 << 14)
 #define GHWCFG4_UTMI_PHY_DATA_WIDTH_SHIFT	14
+#define GHWCFG4_UTMI_PHY_DATA_WIDTH_8		0
+#define GHWCFG4_UTMI_PHY_DATA_WIDTH_16		1
+#define GHWCFG4_UTMI_PHY_DATA_WIDTH_8_OR_16	2
 #define GHWCFG4_XHIBER				(1 << 7)
 #define GHWCFG4_HIBER				(1 << 6)
 #define GHWCFG4_MIN_AHB_FREQ			(1 << 5)

drivers/staging/dwc2/pci.c

@@ -74,7 +74,7 @@ static const struct dwc2_core_params dwc2_module_params = {
 	.max_packet_count		= 511,
 	.host_channels			= -1,
 	.phy_type			= -1,
-	.phy_utmi_width			= 16,	/* 16 bits - NOT DETECTABLE */
+	.phy_utmi_width			= -1,
 	.phy_ulpi_ddr			= -1,
 	.phy_ulpi_ext_vbus		= -1,
 	.i2c_enable			= -1,