--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Intel Keem Bay USB PHY driver
+ * Copyright (C) 2020 Intel Corporation
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.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 GENMASK(6, 0)
+
+/* 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,
+ .max_register = USS_USB_TIEOFFS_CONSTANTS_REG1,
+};
+
+static int keembay_usb_clocks_on(struct keembay_usb_phy *priv)
+{
+ int ret;
+
+ 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;
+ }
+
+ 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 disable: %d\n", ret);
+ return ret;
+ }
+
+ /* Wait 30us to ensure all analog blocks are powered up. */
+ usleep_range(30, 60);
+
+ 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;
+
+ 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;
+
+ 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;
+
+ 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;
+
+ ret = keembay_usb_core_off(priv);
+ if (ret)
+ return ret;
+
+ /*
+ * According to Keem Bay datasheet, wait minimum 20us after clock
+ * enable before bringing PHYs out of reset.
+ */
+ usleep_range(20, 40);
+
+ ret = keembay_usb_phys_on(priv);
+ if (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, 0));
+ if (ret) {
+ dev_err(priv->dev, "error cr clock disable: %d\n", ret);
+ return ret;
+ }
+
+ /*
+ * According to Keem Bay datasheet, wait 2us after disabling the
+ * clock into the USB 3.x parallel interface.
+ */
+ udelay(2);
+
+ 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;
+ }
+
+ 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;
+ }
+
+ 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;
+ }
+
+ /*
+ * According to Keem Bay datasheet, wait 20us after setting the
+ * SRAM load done bit, before releasing the controller reset.
+ */
+ usleep_range(20, 40);
+
+ 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 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, dev->of_node, &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");
projects / users / dwmw2 / linux.git / commitdiff