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Subject[PATCH 2/4] phy: intel: Add Keem Bay USB PHY support
Date
Add support for USB PHY on Intel Keem Bay SoC.

Signed-off-by: Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>
---
drivers/phy/intel/Kconfig | 12 +
drivers/phy/intel/Makefile | 1 +
drivers/phy/intel/phy-intel-keembay-usb.c | 319 ++++++++++++++++++++++
3 files changed, 332 insertions(+)
create mode 100644 drivers/phy/intel/phy-intel-keembay-usb.c

diff --git a/drivers/phy/intel/Kconfig b/drivers/phy/intel/Kconfig
index 58ec695c92ec..914710660557 100644
--- a/drivers/phy/intel/Kconfig
+++ b/drivers/phy/intel/Kconfig
@@ -14,6 +14,18 @@ config PHY_INTEL_KEEMBAY_EMMC
To compile this driver as a module, choose M here: the module
will be called phy-keembay-emmc.ko.

+config PHY_INTEL_KEEMBAY_USB
+ tristate "Intel Keem Bay USB PHY driver"
+ depends on (OF && ARM64) || COMPILE_TEST
+ depends on HAS_IOMEM
+ select GENERIC_PHY
+ select REGMAP_MMIO
+ help
+ Choose this option if you have an Intel Keem Bay SoC.
+
+ To compile this driver as a module, choose M here: the module
+ will be called phy-keembay-usb.ko.
+
config PHY_INTEL_LGM_COMBO
bool "Intel Lightning Mountain ComboPHY driver"
depends on X86 || COMPILE_TEST
diff --git a/drivers/phy/intel/Makefile b/drivers/phy/intel/Makefile
index a5e0af5ccd75..14550981a707 100644
--- a/drivers/phy/intel/Makefile
+++ b/drivers/phy/intel/Makefile
@@ -1,4 +1,5 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_PHY_INTEL_KEEMBAY_EMMC) += phy-intel-keembay-emmc.o
+obj-$(CONFIG_PHY_INTEL_KEEMBAY_USB) += phy-intel-keembay-usb.o
obj-$(CONFIG_PHY_INTEL_LGM_COMBO) += phy-intel-lgm-combo.o
obj-$(CONFIG_PHY_INTEL_LGM_EMMC) += phy-intel-lgm-emmc.o
diff --git a/drivers/phy/intel/phy-intel-keembay-usb.c b/drivers/phy/intel/phy-intel-keembay-usb.c
new file mode 100644
index 000000000000..3db88e765656
--- /dev/null
+++ b/drivers/phy/intel/phy-intel-keembay-usb.c
@@ -0,0 +1,319 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel Keem Bay USB PHY driver
+ * Copyright (C) 2020 Intel Corporation
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+/* USS (USB Subsystem) clock control registers */
+#define USS_CPR_CLK_EN 0x00
+#define USS_CPR_CLK_SET 0x04
+#define USS_CPR_CLK_CLR 0x08
+#define USS_CPR_RST_EN 0x10
+#define USS_CPR_RST_SET 0x14
+#define USS_CPR_RST_CLR 0x18
+
+/* USS clock/reset bit fields */
+#define USS_CPR_PHY_TST BIT(6)
+#define USS_CPR_LOW_JIT BIT(5)
+#define USS_CPR_CORE BIT(4)
+#define USS_CPR_SUSPEND BIT(3)
+#define USS_CPR_ALT_REF BIT(2)
+#define USS_CPR_REF BIT(1)
+#define USS_CPR_SYS BIT(0)
+#define USS_CPR_MASK 0x7f
+
+/* USS APB slave registers */
+#define USS_USB_CTRL_CFG0 0x10
+#define VCC_RESET_N_MASK BIT(31)
+
+#define USS_USB_PHY_CFG0 0x30
+#define POR_MASK BIT(15)
+#define PHY_RESET_MASK BIT(14)
+#define PHY_REF_USE_PAD_MASK BIT(5)
+
+#define USS_USB_PHY_CFG6 0x64
+#define PHY0_SRAM_EXT_LD_DONE_MASK BIT(23)
+
+#define USS_USB_PARALLEL_IF_CTRL 0xa0
+#define USB_PHY_CR_PARA_SEL_MASK BIT(2)
+
+#define USS_USB_TSET_SIGNALS_AND_GLOB 0xac
+#define USB_PHY_CR_PARA_CLK_EN_MASK BIT(7)
+
+#define USS_USB_STATUS_REG 0xb8
+#define PHY0_SRAM_INIT_DONE_MASK BIT(3)
+
+#define USS_USB_TIEOFFS_CONSTANTS_REG1 0xc0
+#define IDDQ_ENABLE_MASK BIT(10)
+
+struct keembay_usb_phy {
+ struct device *dev;
+ struct regmap *regmap_cpr;
+ struct regmap *regmap_slv;
+};
+
+static const struct regmap_config keembay_regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+};
+
+static int keembay_usb_clocks_on(struct keembay_usb_phy *priv)
+{
+ int ret;
+
+ /* Enable USB subsystem clocks */
+ ret = regmap_update_bits(priv->regmap_cpr, USS_CPR_CLK_SET,
+ USS_CPR_MASK, USS_CPR_MASK);
+ if (ret) {
+ dev_err(priv->dev, "error clock set: %d\n", ret);
+ return ret;
+ }
+
+ ret = regmap_update_bits(priv->regmap_cpr, USS_CPR_RST_SET,
+ USS_CPR_MASK, USS_CPR_MASK);
+ if (ret) {
+ dev_err(priv->dev, "error reset set: %d\n", ret);
+ return ret;
+ }
+
+ /*
+ * Clear IDDQ enable bit ensuring all analog blocks are powered
+ * up in USB2.0 PHY.
+ */
+ ret = regmap_update_bits(priv->regmap_slv,
+ USS_USB_TIEOFFS_CONSTANTS_REG1,
+ IDDQ_ENABLE_MASK,
+ FIELD_PREP(IDDQ_ENABLE_MASK, 0));
+ if (ret) {
+ dev_err(priv->dev, "error iddq enable: %d\n", ret);
+ return ret;
+ }
+
+ usleep_range(30, 50);
+
+ /*
+ * Set bit 5 of USS_USB_PHY_CFG0 register.
+ * This selects the external reference pads as the inputs for the
+ * ref clk source as oppose to the alternate ref clk.
+ */
+ ret = regmap_update_bits(priv->regmap_slv, USS_USB_PHY_CFG0,
+ PHY_REF_USE_PAD_MASK,
+ FIELD_PREP(PHY_REF_USE_PAD_MASK, 1));
+ if (ret)
+ dev_err(priv->dev, "error ref clock select: %d\n", ret);
+
+ return ret;
+}
+
+static int keembay_usb_core_off(struct keembay_usb_phy *priv)
+{
+ int ret;
+
+ /* Send the core back to the reset state */
+ ret = regmap_update_bits(priv->regmap_slv, USS_USB_CTRL_CFG0,
+ VCC_RESET_N_MASK,
+ FIELD_PREP(VCC_RESET_N_MASK, 0));
+ if (ret)
+ dev_err(priv->dev, "error core reset: %d\n", ret);
+
+ return ret;
+}
+
+static int keembay_usb_core_on(struct keembay_usb_phy *priv)
+{
+ int ret;
+
+ /* Release core reset (so that AXI slave can be used) */
+ ret = regmap_update_bits(priv->regmap_slv, USS_USB_CTRL_CFG0,
+ VCC_RESET_N_MASK,
+ FIELD_PREP(VCC_RESET_N_MASK, 1));
+ if (ret)
+ dev_err(priv->dev, "error core on: %d\n", ret);
+
+ return ret;
+}
+
+static int keembay_usb_phys_on(struct keembay_usb_phy *priv)
+{
+ int ret;
+
+ /* Bring PHYs out of reset */
+ ret = regmap_update_bits(priv->regmap_slv, USS_USB_PHY_CFG0,
+ POR_MASK | PHY_RESET_MASK,
+ FIELD_PREP(POR_MASK | PHY_RESET_MASK, 0));
+ if (ret)
+ dev_err(priv->dev, "error phys on: %d\n", ret);
+
+ return ret;
+}
+
+static int keembay_usb_phy_init(struct phy *phy)
+{
+ struct keembay_usb_phy *priv = phy_get_drvdata(phy);
+ u32 val;
+ int ret;
+
+ /* Reset the controller and both the USB2.0 and USB3.1 PHYs */
+ ret = keembay_usb_core_off(priv);
+ if (ret)
+ return ret;
+
+ /* Wait minimum 20us after clock enable */
+ usleep_range(20, 50);
+
+ /* to bring PHYs out of reset */
+ ret = keembay_usb_phys_on(priv);
+ if (ret)
+ return ret;
+
+ /*
+ * Enable USB3.1 Control Register Parallel Interface
+ *
+ * (1) Clear bit 7 of USS_USB_TSET_SIGNALS_AND_GLOB register
+ * to disable the clock into the USB3.X parallel interface.
+ * (2) Wait 2us.
+ * (3) Set bit 2 of USS_USB_PARALLEL_IF_CTRL register to choose
+ * CR interface instead of JTAG.
+ * (4) Set bit 7 of USS_USB_TSET_SIGNALS_AND_GLOB register
+ * to reenable the clock into the USB3.X parallel interface.
+ */
+ ret = regmap_update_bits(priv->regmap_slv,
+ USS_USB_TSET_SIGNALS_AND_GLOB,
+ USB_PHY_CR_PARA_CLK_EN_MASK,
+ FIELD_PREP(USB_PHY_CR_PARA_CLK_EN_MASK, 0));
+ if (ret) {
+ dev_err(priv->dev, "error cr clock disable: %d\n", ret);
+ return ret;
+ }
+
+ usleep_range(2, 10);
+
+ ret = regmap_update_bits(priv->regmap_slv,
+ USS_USB_PARALLEL_IF_CTRL,
+ USB_PHY_CR_PARA_SEL_MASK,
+ FIELD_PREP(USB_PHY_CR_PARA_SEL_MASK, 1));
+ if (ret) {
+ dev_err(priv->dev, "error cr select: %d\n", ret);
+ return ret;
+ }
+
+ ret = regmap_update_bits(priv->regmap_slv,
+ USS_USB_TSET_SIGNALS_AND_GLOB,
+ USB_PHY_CR_PARA_CLK_EN_MASK,
+ FIELD_PREP(USB_PHY_CR_PARA_CLK_EN_MASK, 1));
+ if (ret) {
+ dev_err(priv->dev, "error cr clock enable: %d\n", ret);
+ return ret;
+ }
+
+ /* Wait for USB3.1 PHY0 SRAM init done */
+ ret = regmap_read_poll_timeout(priv->regmap_slv, USS_USB_STATUS_REG,
+ val, (val & PHY0_SRAM_INIT_DONE_MASK),
+ USEC_PER_MSEC, 10 * USEC_PER_MSEC);
+ if (ret) {
+ dev_err(priv->dev, "SRAM init not done: %d\n", ret);
+ return ret;
+ }
+
+ /* Set the SRAM load done bit */
+ ret = regmap_update_bits(priv->regmap_slv, USS_USB_PHY_CFG6,
+ PHY0_SRAM_EXT_LD_DONE_MASK,
+ FIELD_PREP(PHY0_SRAM_EXT_LD_DONE_MASK, 1));
+ if (ret) {
+ dev_err(priv->dev, "error SRAM init done set: %d\n", ret);
+ return ret;
+ }
+
+ /* Wait 20us */
+ usleep_range(20, 50);
+
+ /* and release the controller reset */
+ return keembay_usb_core_on(priv);
+}
+
+static const struct phy_ops ops = {
+ .init = keembay_usb_phy_init,
+ .owner = THIS_MODULE,
+};
+
+static int keembay_usb_phy_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *np = dev->of_node;
+ struct keembay_usb_phy *priv;
+ struct phy *generic_phy;
+ struct phy_provider *phy_provider;
+ void __iomem *base;
+ int ret;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ base = devm_platform_ioremap_resource_byname(pdev, "cpr-apb-base");
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ priv->regmap_cpr = devm_regmap_init_mmio(dev, base,
+ &keembay_regmap_config);
+ if (IS_ERR(priv->regmap_cpr))
+ return PTR_ERR(priv->regmap_cpr);
+
+ base = devm_platform_ioremap_resource_byname(pdev, "slv-apb-base");
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ priv->regmap_slv = devm_regmap_init_mmio(dev, base,
+ &keembay_regmap_config);
+ if (IS_ERR(priv->regmap_slv))
+ return PTR_ERR(priv->regmap_slv);
+
+ generic_phy = devm_phy_create(dev, np, &ops);
+ if (IS_ERR(generic_phy))
+ return dev_err_probe(dev, PTR_ERR(generic_phy),
+ "failed to create PHY\n");
+
+ phy_set_drvdata(generic_phy, priv);
+ phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+ if (IS_ERR(phy_provider))
+ return dev_err_probe(dev, PTR_ERR(phy_provider),
+ "failed to register phy provider\n");
+
+ /* Setup USB subsystem clocks */
+ ret = keembay_usb_clocks_on(priv);
+ if (ret)
+ return ret;
+
+ /* and turn on the DWC3 core, prior to DWC3 driver init */
+ return keembay_usb_core_on(priv);
+}
+
+static const struct of_device_id keembay_usb_phy_dt_ids[] = {
+ { .compatible = "intel,keembay-usb-phy" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, keembay_usb_phy_dt_ids);
+
+static struct platform_driver keembay_usb_phy_driver = {
+ .probe = keembay_usb_phy_probe,
+ .driver = {
+ .name = "keembay-usb-phy",
+ .of_match_table = keembay_usb_phy_dt_ids,
+ },
+};
+module_platform_driver(keembay_usb_phy_driver);
+
+MODULE_AUTHOR("Wan Ahmad Zainie <wan.ahmad.zainie.wan.mohamad@intel.com>");
+MODULE_DESCRIPTION("Intel Keem Bay USB PHY driver");
+MODULE_LICENSE("GPL v2");
--
2.17.1
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