[PATCH v4 11/13] phy: usb: bdc: Fix occasional failure with BDC on 7211

[Al Cooper <alcooperx@xxxxxxxxx>]

The BDC "Read Transaction Size" needs to be changed from 1024
bytes to 256 bytes to prevent occasional transaction failures.

Signed-off-by: Al Cooper <alcooperx@xxxxxxxxx>
---
 .../phy/broadcom/phy-brcm-usb-init-synopsys.c | 18 +++++++++++++++
 drivers/phy/broadcom/phy-brcm-usb-init.h      |  1 +
 drivers/phy/broadcom/phy-brcm-usb.c           | 23 +++++++++++++++----
 3 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c b/drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c
index ce4226ac552e..60969827a67a 100644
--- a/drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c
+++ b/drivers/phy/broadcom/phy-brcm-usb-init-synopsys.c
@@ -70,6 +70,11 @@
 #define USB_GMDIOCSR	0
 #define USB_GMDIOGEN	4
 
+/* Register definitions for the BDC EC block in 7211b0 */
+#define BDC_EC_AXIRDA			0x0c
+#define   BDC_EC_AXIRDA_RTS_MASK			0xf0000000
+#define   BDC_EC_AXIRDA_RTS_SHIFT			28
+
 
 static void usb_mdio_write_7211b0(struct brcm_usb_init_params *params,
 				  uint8_t addr, uint16_t data)
@@ -198,6 +203,7 @@ static void usb_init_common_7211b0(struct brcm_usb_init_params *params)
 {
 	void __iomem *ctrl = params->regs[BRCM_REGS_CTRL];
 	void __iomem *usb_phy = params->regs[BRCM_REGS_USB_PHY];
+	void __iomem *bdc_ec = params->regs[BRCM_REGS_BDC_EC];
 	int timeout_ms = PHY_LOCK_TIMEOUT_MS;
 	u32 reg;
 
@@ -230,6 +236,18 @@ static void usb_init_common_7211b0(struct brcm_usb_init_params *params)
 
 	usb_init_common(params);
 
+	/*
+	 * The BDC controller will get occasional failures with
+	 * the default "Read Transaction Size" of 6 (1024 bytes).
+	 * Set it to 4 (256 bytes).
+	 */
+	if ((params->mode != USB_CTLR_MODE_HOST) && bdc_ec) {
+		reg = brcm_usb_readl(bdc_ec + BDC_EC_AXIRDA);
+		reg &= ~BDC_EC_AXIRDA_RTS_MASK;
+		reg |= (0x4 << BDC_EC_AXIRDA_RTS_SHIFT);
+		brcm_usb_writel(reg, bdc_ec + BDC_EC_AXIRDA);
+	}
+
 	/*
 	 * Disable FSM, otherwise the PHY will auto suspend when no
 	 * device is connected and will be reset on resume.
diff --git a/drivers/phy/broadcom/phy-brcm-usb-init.h b/drivers/phy/broadcom/phy-brcm-usb-init.h
index 2ea81daf295e..4cdd9cc1c5a3 100644
--- a/drivers/phy/broadcom/phy-brcm-usb-init.h
+++ b/drivers/phy/broadcom/phy-brcm-usb-init.h
@@ -19,6 +19,7 @@ enum brcmusb_reg_sel {
 	BRCM_REGS_XHCI_GBL,
 	BRCM_REGS_USB_PHY,
 	BRCM_REGS_USB_MDIO,
+	BRCM_REGS_BDC_EC,
 	BRCM_REGS_MAX
 };
 
diff --git a/drivers/phy/broadcom/phy-brcm-usb.c b/drivers/phy/broadcom/phy-brcm-usb.c
index c82d7ec15334..cc5763ace3ad 100644
--- a/drivers/phy/broadcom/phy-brcm-usb.c
+++ b/drivers/phy/broadcom/phy-brcm-usb.c
@@ -36,6 +36,7 @@ struct value_to_name_map {
 struct match_chip_info {
 	void *init_func;
 	u8 required_regs[BRCM_REGS_MAX + 1];
+	u8 optional_reg;
 };
 
 static struct value_to_name_map brcm_dr_mode_to_name[] = {
@@ -71,7 +72,7 @@ struct brcm_usb_phy_data {
 };
 
 static s8 *node_reg_names[BRCM_REGS_MAX] = {
-	"crtl", "xhci_ec", "xhci_gbl", "usb_phy", "usb_mdio"
+	"crtl", "xhci_ec", "xhci_gbl", "usb_phy", "usb_mdio", "bdc_ec"
 };
 
 static irqreturn_t brcm_usb_phy_wake_isr(int irq, void *dev_id)
@@ -271,6 +272,7 @@ static struct match_chip_info chip_info_7211b0 = {
 		BRCM_REGS_USB_MDIO,
 		-1,
 	},
+	.optional_reg = BRCM_REGS_BDC_EC,
 };
 
 static struct match_chip_info chip_info_7445 = {
@@ -300,7 +302,8 @@ static const struct of_device_id brcm_usb_dt_ids[] = {
 
 static int brcm_usb_get_regs(struct platform_device *pdev,
 			     enum brcmusb_reg_sel regs,
-			     struct  brcm_usb_init_params *ini)
+			     struct  brcm_usb_init_params *ini,
+			     bool optional)
 {
 	struct resource *res;
 
@@ -317,7 +320,13 @@ static int brcm_usb_get_regs(struct platform_device *pdev,
 				return 0;
 		}
 		if (res == NULL) {
-			dev_err(&pdev->dev, "can't get %s base address\n",
+			if (optional) {
+				dev_dbg(&pdev->dev,
+					"Optional reg %s not found\n",
+					node_reg_names[regs]);
+				return 0;
+			}
+			dev_err(&pdev->dev, "can't get %s base addr\n",
 				node_reg_names[regs]);
 			return 1;
 		}
@@ -460,7 +469,13 @@ static int brcm_usb_phy_probe(struct platform_device *pdev)
 			break;
 
 		err = brcm_usb_get_regs(pdev, info->required_regs[x],
-					&priv->ini);
+					&priv->ini, false);
+		if (err)
+			return -EINVAL;
+	}
+	if (info->optional_reg) {
+		err = brcm_usb_get_regs(pdev, info->optional_reg,
+					&priv->ini, true);
 		if (err)
 			return -EINVAL;
 	}
-- 
2.17.1