This patch adds a new driver for the Qualcomm USB 3.0 PHY that exists on some
Qualcomm platforms.  This driver uses the generic PHY framework and will
interact with the DWC3 controller.

Signed-off-by: Andy Gross <agr...@codeaurora.org>
---
 drivers/phy/Kconfig         |   11 +
 drivers/phy/Makefile        |    1 +
 drivers/phy/phy-qcom-dwc3.c |  483 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 495 insertions(+)
 create mode 100644 drivers/phy/phy-qcom-dwc3.c

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 0dd7427..5d56161 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -230,4 +230,15 @@ config PHY_XGENE
        help
          This option enables support for APM X-Gene SoC multi-purpose PHY.
 
+config PHY_QCOM_DWC3
+       tristate "QCOM DWC3 USB PHY support"
+       depends on ARCH_QCOM
+       depends on HAS_IOMEM
+       depends on OF
+       select GENERIC_PHY
+       help
+         This option enables support for the Synopsis PHYs present inside the
+         Qualcomm USB3.0 DWC3 controller.  This driver supports both HS and SS
+         PHY controllers.
+
 endmenu
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 95c69ed..aa16f30 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -28,3 +28,4 @@ obj-$(CONFIG_PHY_QCOM_IPQ806X_SATA)   += 
phy-qcom-ipq806x-sata.o
 obj-$(CONFIG_PHY_ST_SPEAR1310_MIPHY)   += phy-spear1310-miphy.o
 obj-$(CONFIG_PHY_ST_SPEAR1340_MIPHY)   += phy-spear1340-miphy.o
 obj-$(CONFIG_PHY_XGENE)                        += phy-xgene.o
+obj-$(CONFIG_PHY_QCOM_DWC3)            += phy-qcom-dwc3.o
diff --git a/drivers/phy/phy-qcom-dwc3.c b/drivers/phy/phy-qcom-dwc3.c
new file mode 100644
index 0000000..2c7b316
--- /dev/null
+++ b/drivers/phy/phy-qcom-dwc3.c
@@ -0,0 +1,483 @@
+/* Copyright (c) 2013-2014, Code Aurora Forum. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+
+/**
+ *  USB QSCRATCH Hardware registers
+ */
+#define QSCRATCH_GENERAL_CFG           (0x08)
+#define HSUSB_PHY_CTRL_REG             (0x10)
+
+/* PHY_CTRL_REG */
+#define HSUSB_CTRL_DMSEHV_CLAMP                        BIT(24)
+#define HSUSB_CTRL_USB2_SUSPEND                        BIT(23)
+#define HSUSB_CTRL_UTMI_CLK_EN                 BIT(21)
+#define        HSUSB_CTRL_UTMI_OTG_VBUS_VALID          BIT(20)
+#define HSUSB_CTRL_USE_CLKCORE                 BIT(18)
+#define HSUSB_CTRL_DPSEHV_CLAMP                        BIT(17)
+#define HSUSB_CTRL_COMMONONN                   BIT(11)
+#define HSUSB_CTRL_ID_HV_CLAMP                 BIT(9)
+#define HSUSB_CTRL_OTGSESSVLD_CLAMP            BIT(8)
+#define HSUSB_CTRL_CLAMP_EN                    BIT(7)
+#define HSUSB_CTRL_RETENABLEN                  BIT(1)
+#define HSUSB_CTRL_POR                         BIT(0)
+
+/* QSCRATCH_GENERAL_CFG */
+#define HSUSB_GCFG_XHCI_REV            BIT(2)
+
+/**
+ *  USB QSCRATCH Hardware registers
+ */
+#define SSUSB_PHY_CTRL_REG             (0x00)
+#define SSUSB_PHY_PARAM_CTRL_1         (0x04)
+#define SSUSB_PHY_PARAM_CTRL_2         (0x08)
+#define CR_PROTOCOL_DATA_IN_REG                (0x0c)
+#define CR_PROTOCOL_DATA_OUT_REG       (0x10)
+#define CR_PROTOCOL_CAP_ADDR_REG       (0x14)
+#define CR_PROTOCOL_CAP_DATA_REG       (0x18)
+#define CR_PROTOCOL_READ_REG           (0x1c)
+#define CR_PROTOCOL_WRITE_REG          (0x20)
+
+/* PHY_CTRL_REG */
+#define SSUSB_CTRL_REF_USE_PAD         BIT(28)
+#define SSUSB_CTRL_TEST_POWERDOWN      BIT(27)
+#define SSUSB_CTRL_LANE0_PWR_PRESENT   BIT(24)
+#define SSUSB_CTRL_SS_PHY_EN           BIT(8)
+#define SSUSB_CTRL_SS_PHY_RESET                BIT(7)
+
+/* SSPHY control registers */
+#define SSPHY_CTRL_RX_OVRD_IN_HI(lane) (0x1006 + 0x100 * lane)
+#define SSPHY_CTRL_TX_OVRD_DRV_LO(lane)        (0x1002 + 0x100 * lane)
+
+/* RX OVRD IN HI bits */
+#define RX_OVRD_IN_HI_RX_RESET_OVRD            BIT(13)
+#define RX_OVRD_IN_HI_RX_RX_RESET              BIT(12)
+#define RX_OVRD_IN_HI_RX_EQ_OVRD               BIT(11)
+#define RX_OVRD_IN_HI_RX_EQ_MASK               0x0700
+#define RX_OVRD_IN_HI_RX_EQ_SHIFT              8
+#define RX_OVRD_IN_HI_RX_EQ_EN_OVRD            BIT(7)
+#define RX_OVRD_IN_HI_RX_EQ_EN                 BIT(6)
+#define RX_OVRD_IN_HI_RX_LOS_FILTER_OVRD       BIT(5)
+#define RX_OVRD_IN_HI_RX_LOS_FILTER_MASK       0x0018
+#define RX_OVRD_IN_HI_RX_RATE_OVRD             BIT(2)
+#define RX_OVRD_IN_HI_RX_RATE_MASK             0x0003
+
+/* TX OVRD DRV LO register bits */
+#define TX_OVRD_DRV_LO_AMPLITUDE_MASK  0x007F
+#define TX_OVRD_DRV_LO_PREEMPH_MASK    0x3F80
+#define TX_OVRD_DRV_LO_PREEMPH_SHIFT   7
+#define TX_OVRD_DRV_LO_EN              BIT(14)
+
+struct qcom_dwc3_usb_phy {
+       void __iomem            *base;
+       struct device           *dev;
+       struct phy *phy;
+
+       int (*phy_init)(struct qcom_dwc3_usb_phy *phy_dwc3);
+       int (*phy_exit)(struct qcom_dwc3_usb_phy *phy_dwc3);
+
+       struct clk              *xo_clk;
+       struct clk              *ref_clk;
+};
+
+/**
+ * Write register and read back masked value to confirm it is written
+ *
+ * @base - QCOM DWC3 PHY base virtual address.
+ * @offset - register offset.
+ * @mask - register bitmask specifying what should be updated
+ * @val - value to write.
+ */
+static inline void qcom_dwc3_phy_write_readback(
+       struct qcom_dwc3_usb_phy *phy_dwc3, u32 offset,
+       const u32 mask, u32 val)
+{
+       u32 write_val, tmp = readl(phy_dwc3->base + offset);
+
+       tmp &= ~mask;           /* retain other bits */
+       write_val = tmp | val;
+
+       writel(write_val, phy_dwc3->base + offset);
+
+       /* Read back to see if val was written */
+       tmp = readl(phy_dwc3->base + offset);
+       tmp &= mask;            /* clear other bits */
+
+       if (tmp != val)
+               dev_err(phy_dwc3->dev, "write: %x to QSCRATCH: %x FAILED\n",
+                       val, offset);
+}
+
+static int wait_for_latch(void __iomem *addr)
+{
+       u32 retry = 10;
+
+       while (true) {
+               if (!readl(addr))
+                       break;
+
+               if (--retry == 0)
+                       return -ETIMEDOUT;
+
+               usleep_range(10, 20);
+       }
+
+       return 0;
+}
+
+/**
+ * Write SSPHY register
+ *
+ * @base - QCOM DWC3 PHY base virtual address.
+ * @addr - SSPHY address to write.
+ * @val - value to write.
+ */
+static int qcom_dwc3_ss_write_phycreg(void __iomem *base, u32 addr, u32 val)
+{
+       int ret;
+
+       writel(addr, base + CR_PROTOCOL_DATA_IN_REG);
+       writel(0x1, base + CR_PROTOCOL_CAP_ADDR_REG);
+
+       ret = wait_for_latch(base + CR_PROTOCOL_CAP_ADDR_REG);
+       if (ret)
+               goto err_wait;
+
+       writel(val, base + CR_PROTOCOL_DATA_IN_REG);
+       writel(0x1, base + CR_PROTOCOL_CAP_DATA_REG);
+
+       ret = wait_for_latch(base + CR_PROTOCOL_CAP_DATA_REG);
+       if (ret)
+               goto err_wait;
+
+       writel(0x1, base + CR_PROTOCOL_WRITE_REG);
+
+       ret = wait_for_latch(base + CR_PROTOCOL_WRITE_REG);
+
+err_wait:
+       return ret;
+}
+
+/**
+ * Read SSPHY register.
+ *
+ * @base - QCOM DWC3 PHY base virtual address.
+ * @addr - SSPHY address to read.
+ */
+static int qcom_dwc3_ss_read_phycreg(void __iomem *base, u32 addr, u32 *val)
+{
+       int ret;
+       bool first_read = true;
+
+       writel(addr, base + CR_PROTOCOL_DATA_IN_REG);
+       writel(0x1, base + CR_PROTOCOL_CAP_ADDR_REG);
+
+       ret = wait_for_latch(base + CR_PROTOCOL_CAP_ADDR_REG);
+       if (ret)
+               goto err_wait;
+
+       /*
+        * Due to hardware bug, first read of SSPHY register might be
+        * incorrect. Hence as workaround, SW should perform SSPHY register
+        * read twice, but use only second read and ignore first read.
+        */
+retry:
+       writel(0x1, base + CR_PROTOCOL_READ_REG);
+
+       ret = wait_for_latch(base + CR_PROTOCOL_READ_REG);
+       if (ret)
+               goto err_wait;
+
+       if (first_read) {
+               readl(base + CR_PROTOCOL_DATA_OUT_REG);
+               first_read = false;
+               goto retry;
+       }
+
+       *val = readl(base + CR_PROTOCOL_DATA_OUT_REG);
+
+err_wait:
+       return ret;
+}
+
+static int qcom_dwc3_phy_power_on(struct phy *phy)
+{
+       int ret;
+       struct qcom_dwc3_usb_phy *phy_dwc3 = phy_get_drvdata(phy);
+
+       ret = clk_prepare_enable(phy_dwc3->xo_clk);
+       if (ret)
+               return ret;
+
+       ret = clk_prepare_enable(phy_dwc3->ref_clk);
+       if (ret)
+               clk_disable_unprepare(phy_dwc3->xo_clk);
+
+       return ret;
+}
+
+static int qcom_dwc3_phy_power_off(struct phy *phy)
+{
+       struct qcom_dwc3_usb_phy *phy_dwc3 = phy_get_drvdata(phy);
+
+       clk_disable_unprepare(phy_dwc3->ref_clk);
+       clk_disable_unprepare(phy_dwc3->xo_clk);
+
+       return 0;
+}
+
+static int qcom_dwc3_hs_phy_init(struct qcom_dwc3_usb_phy *phy_dwc3)
+{
+       u32 val;
+
+       /*
+        * HSPHY Initialization: Enable UTMI clock, select 19.2MHz fsel
+        * enable clamping, and disable RETENTION (power-on default is ENABLED)
+        */
+       val = HSUSB_CTRL_DPSEHV_CLAMP | HSUSB_CTRL_DMSEHV_CLAMP |
+               HSUSB_CTRL_RETENABLEN  | HSUSB_CTRL_COMMONONN |
+               HSUSB_CTRL_OTGSESSVLD_CLAMP | HSUSB_CTRL_ID_HV_CLAMP |
+               HSUSB_CTRL_DPSEHV_CLAMP | HSUSB_CTRL_UTMI_OTG_VBUS_VALID |
+               HSUSB_CTRL_UTMI_CLK_EN | HSUSB_CTRL_CLAMP_EN | 0x70;
+
+       /* use core clock if external reference is not present */
+       if (!phy_dwc3->xo_clk)
+               val |= HSUSB_CTRL_USE_CLKCORE;
+
+       writel(val, phy_dwc3->base + HSUSB_PHY_CTRL_REG);
+       usleep_range(2000, 2200);
+
+       /* Disable (bypass) VBUS and ID filters */
+       writel(HSUSB_GCFG_XHCI_REV, phy_dwc3->base + QSCRATCH_GENERAL_CFG);
+
+       return 0;
+}
+
+static int qcom_dwc3_ss_phy_init(struct qcom_dwc3_usb_phy *phy_dwc3)
+{
+       int ret;
+       u32 data = 0;
+
+       /* reset phy */
+       data = readl_relaxed(phy_dwc3->base + SSUSB_PHY_CTRL_REG);
+       writel_relaxed(data | SSUSB_CTRL_SS_PHY_RESET,
+               phy_dwc3->base + SSUSB_PHY_CTRL_REG);
+       usleep_range(2000, 2200);
+       writel_relaxed(data, phy_dwc3->base + SSUSB_PHY_CTRL_REG);
+
+       /* clear REF_PAD if we don't have XO clk */
+       if (!phy_dwc3->xo_clk)
+               data &= ~SSUSB_CTRL_REF_USE_PAD;
+       else
+               data |= SSUSB_CTRL_REF_USE_PAD;
+
+       writel_relaxed(data, phy_dwc3->base + SSUSB_PHY_CTRL_REG);
+       msleep(30);
+
+       data |= SSUSB_CTRL_SS_PHY_EN | SSUSB_CTRL_LANE0_PWR_PRESENT;
+       writel_relaxed(data, phy_dwc3->base + SSUSB_PHY_CTRL_REG);
+
+       /*
+        * Fix RX Equalization setting as follows
+        * LANE0.RX_OVRD_IN_HI. RX_EQ_EN set to 0
+        * LANE0.RX_OVRD_IN_HI.RX_EQ_EN_OVRD set to 1
+        * LANE0.RX_OVRD_IN_HI.RX_EQ set to 3
+        * LANE0.RX_OVRD_IN_HI.RX_EQ_OVRD set to 1
+        */
+       ret = qcom_dwc3_ss_read_phycreg(phy_dwc3->base,
+                       SSPHY_CTRL_RX_OVRD_IN_HI(0), &data);
+       if (ret)
+               goto err_phy_trans;
+
+       data &= ~RX_OVRD_IN_HI_RX_EQ_EN;
+       data |= RX_OVRD_IN_HI_RX_EQ_EN_OVRD;
+       data &= ~RX_OVRD_IN_HI_RX_EQ_MASK;
+       data |= 0x3 << RX_OVRD_IN_HI_RX_EQ_SHIFT;
+       data |= RX_OVRD_IN_HI_RX_EQ_OVRD;
+       ret = qcom_dwc3_ss_write_phycreg(phy_dwc3->base,
+               SSPHY_CTRL_RX_OVRD_IN_HI(0), data);
+       if (ret)
+               goto err_phy_trans;
+
+       /*
+        * Set EQ and TX launch amplitudes as follows
+        * LANE0.TX_OVRD_DRV_LO.PREEMPH set to 22
+        * LANE0.TX_OVRD_DRV_LO.AMPLITUDE set to 127
+        * LANE0.TX_OVRD_DRV_LO.EN set to 1.
+        */
+       ret = qcom_dwc3_ss_read_phycreg(phy_dwc3->base,
+               SSPHY_CTRL_TX_OVRD_DRV_LO(0), &data);
+       if (ret)
+               goto err_phy_trans;
+
+       data &= ~TX_OVRD_DRV_LO_PREEMPH_MASK;
+       data |= 0x16 << TX_OVRD_DRV_LO_PREEMPH_SHIFT;
+       data &= ~TX_OVRD_DRV_LO_AMPLITUDE_MASK;
+       data |= 0x7f;
+       data |= TX_OVRD_DRV_LO_EN;
+       ret = qcom_dwc3_ss_write_phycreg(phy_dwc3->base,
+               SSPHY_CTRL_TX_OVRD_DRV_LO(0), data);
+       if (ret)
+               goto err_phy_trans;
+
+       /*
+        * Set the QSCRATCH PHY_PARAM_CTRL1 parameters as follows
+        * TX_FULL_SWING [26:20] amplitude to 127
+        * TX_DEEMPH_3_5DB [13:8] to 22
+        * LOS_BIAS [2:0] to 0x5
+        */
+       qcom_dwc3_phy_write_readback(phy_dwc3, SSUSB_PHY_PARAM_CTRL_1,
+                                  0x07f03f07, 0x07f01605);
+
+err_phy_trans:
+       return ret;
+}
+
+static int qcom_dwc3_ss_phy_exit(struct qcom_dwc3_usb_phy *phy_dwc3)
+{
+       /* Sequence to put SSPHY in low power state:
+        * 1. Clear REF_PHY_EN in PHY_CTRL_REG
+        * 2. Clear REF_USE_PAD in PHY_CTRL_REG
+        * 3. Set TEST_POWERED_DOWN in PHY_CTRL_REG to enable PHY retention
+        * 4. Disable SSPHY ref clk
+        */
+       qcom_dwc3_phy_write_readback(phy_dwc3, SSUSB_PHY_CTRL_REG,
+               SSUSB_CTRL_SS_PHY_EN, 0x0);
+       qcom_dwc3_phy_write_readback(phy_dwc3, SSUSB_PHY_CTRL_REG,
+               SSUSB_CTRL_REF_USE_PAD, 0x0);
+       qcom_dwc3_phy_write_readback(phy_dwc3, SSUSB_PHY_CTRL_REG,
+               0x0, SSUSB_CTRL_TEST_POWERDOWN);
+
+       return 0;
+}
+
+static int qcom_dwc3_phy_init(struct phy *phy)
+{
+       struct qcom_dwc3_usb_phy *phy_dwc3 = phy_get_drvdata(phy);
+
+       if (phy_dwc3->phy_init)
+               return phy_dwc3->phy_init(phy_dwc3);
+
+       return 0;
+}
+
+static int qcom_dwc3_phy_exit(struct phy *phy)
+{
+       struct qcom_dwc3_usb_phy *phy_dwc3 = phy_get_drvdata(phy);
+
+       if (phy_dwc3->phy_exit)
+               return qcom_dwc3_ss_phy_exit(phy_dwc3);
+
+       return 0;
+}
+
+static struct phy_ops qcom_dwc3_phy_ops = {
+       .init           = qcom_dwc3_phy_init,
+       .exit           = qcom_dwc3_phy_exit,
+       .power_on       = qcom_dwc3_phy_power_on,
+       .power_off      = qcom_dwc3_phy_power_off,
+       .owner          = THIS_MODULE,
+};
+
+static const struct of_device_id qcom_dwc3_phy_table[] = {
+       { .compatible = "qcom,dwc3-hs-usb-phy", },
+       { .compatible = "qcom,dwc3-ss-usb-phy", },
+       { /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, qcom_dwc3_phy_table);
+
+static int qcom_dwc3_phy_probe(struct platform_device *pdev)
+{
+       struct qcom_dwc3_usb_phy        *phy_dwc3;
+       struct phy_provider             *phy_provider;
+       struct resource                 *res;
+
+       phy_dwc3 = devm_kzalloc(&pdev->dev, sizeof(*phy_dwc3), GFP_KERNEL);
+       if (!phy_dwc3)
+               return -ENOMEM;
+
+       platform_set_drvdata(pdev, phy_dwc3);
+
+       phy_dwc3->dev = &pdev->dev;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       phy_dwc3->base = devm_ioremap_resource(phy_dwc3->dev, res);
+       if (IS_ERR(phy_dwc3->base))
+               return PTR_ERR(phy_dwc3->base);
+
+       phy_dwc3->ref_clk = devm_clk_get(phy_dwc3->dev, "ref");
+       if (IS_ERR(phy_dwc3->ref_clk)) {
+               dev_dbg(phy_dwc3->dev, "cannot get reference clock\n");
+               return PTR_ERR(phy_dwc3->ref_clk);
+       }
+
+       if (of_device_is_compatible(pdev->dev.of_node,
+                       "qcom,dwc3-hs-usb-phy")) {
+               clk_set_rate(phy_dwc3->ref_clk, 60000000);
+               phy_dwc3->phy_init = qcom_dwc3_hs_phy_init;
+       } else if (of_device_is_compatible(pdev->dev.of_node,
+                       "qcom,dwc3-ss-usb-phy")) {
+               phy_dwc3->phy_init = qcom_dwc3_ss_phy_init;
+               phy_dwc3->phy_exit = qcom_dwc3_ss_phy_exit;
+               clk_set_rate(phy_dwc3->ref_clk, 125000000);
+       } else {
+               dev_err(phy_dwc3->dev, "Unknown phy\n");
+               return -EINVAL;
+       }
+
+       phy_dwc3->xo_clk = devm_clk_get(phy_dwc3->dev, "xo");
+       if (IS_ERR(phy_dwc3->xo_clk)) {
+               dev_dbg(phy_dwc3->dev, "cannot get TCXO clock\n");
+               phy_dwc3->xo_clk = NULL;
+       }
+
+       phy_dwc3->phy = devm_phy_create(phy_dwc3->dev, NULL, &qcom_dwc3_phy_ops,
+               NULL);
+
+       if (IS_ERR(phy_dwc3->phy))
+               return PTR_ERR(phy_dwc3->phy);
+
+       phy_set_drvdata(phy_dwc3->phy, phy_dwc3);
+
+       phy_provider = devm_of_phy_provider_register(phy_dwc3->dev,
+                       of_phy_simple_xlate);
+
+       if (IS_ERR(phy_provider))
+               return PTR_ERR(phy_provider);
+
+       return 0;
+}
+
+static struct platform_driver qcom_dwc3_phy_driver = {
+       .probe          = qcom_dwc3_phy_probe,
+       .driver         = {
+               .name   = "qcom-dwc3-usb-phy",
+               .owner  = THIS_MODULE,
+               .of_match_table = qcom_dwc3_phy_table,
+       },
+};
+
+module_platform_driver(qcom_dwc3_phy_driver);
+
+MODULE_ALIAS("platform:phy-qcom-dwc3");
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Andy Gross <agr...@codeaurora.org>");
+MODULE_AUTHOR("Ivan T. Ivanov <iiva...@mm-sol.com>");
+MODULE_DESCRIPTION("DesignWare USB3 QCOM PHY driver");
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

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