[PATCH v3 2/2] drivers: usb: dwc3: Add AM62 USB wrapper driver
From: Aswath Govindraju
Date: Wed Apr 06 2022 - 12:32:01 EST
In AM62 SoC, the Designware Core USB3 IP is progammed to operate in USB2.0
only mode. Add driver for AM62 USB DWC3 Wrapper.
Signed-off-by: Aswath Govindraju <a-govindraju@xxxxxx>
---
changes since v2:
- Removed the implementation of detecting the role from the wrapper
driver and moved the implementation to using linux,extcon-usb-gpio
driver for role detection.
- Updated the binding documentation and example to reflect the same.
drivers/usb/dwc3/Kconfig | 9 +
drivers/usb/dwc3/Makefile | 1 +
drivers/usb/dwc3/dwc3-am62.c | 446 +++++++++++++++++++++++++++++++++++
3 files changed, 456 insertions(+)
create mode 100644 drivers/usb/dwc3/dwc3-am62.c
diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index c483f28b695d..cd9a734522a7 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -159,4 +159,13 @@ config USB_DWC3_XILINX
This driver handles both ZynqMP and Versal SoC operations.
Say 'Y' or 'M' if you have one such device.
+config USB_DWC3_AM62
+ tristate "Texas Instruments AM62 Platforms"
+ depends on ARCH_K3 || COMPILE_TEST
+ default USB_DWC3
+ help
+ Support TI's AM62 platforms with DesignWare Core USB3 IP.
+ The Designware Core USB3 IP is progammed to operate in
+ in USB 2.0 mode only.
+ Say 'Y' or 'M' here if you have one such device
endif
diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
index 2d499de6f66a..9f66bd82b639 100644
--- a/drivers/usb/dwc3/Makefile
+++ b/drivers/usb/dwc3/Makefile
@@ -42,6 +42,7 @@ endif
# and allyesconfig builds.
##
+obj-$(CONFIG_USB_DWC3_AM62) += dwc3-am62.o
obj-$(CONFIG_USB_DWC3_OMAP) += dwc3-omap.o
obj-$(CONFIG_USB_DWC3_EXYNOS) += dwc3-exynos.o
obj-$(CONFIG_USB_DWC3_PCI) += dwc3-pci.o
diff --git a/drivers/usb/dwc3/dwc3-am62.c b/drivers/usb/dwc3/dwc3-am62.c
new file mode 100644
index 000000000000..5700258c8deb
--- /dev/null
+++ b/drivers/usb/dwc3/dwc3-am62.c
@@ -0,0 +1,446 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * dwc3-am62.c - TI specific Glue layer for AM62 DWC3 USB Controller
+ *
+ * Copyright (C) 2022 Texas Instruments Incorporated - https://www.ti.com
+ */
+
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/workqueue.h>
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/clk.h>
+#include <linux/regmap.h>
+#include <linux/devm-helpers.h>
+#include <linux/pinctrl/consumer.h>
+
+/* USB WRAPPER register offsets */
+#define USBSS_PID 0x0
+#define USBSS_OVERCURRENT_CTRL 0x4
+#define USBSS_PHY_CONFIG 0x8
+#define USBSS_PHY_TEST 0xc
+#define USBSS_CORE_STAT 0x14
+#define USBSS_HOST_VBUS_CTRL 0x18
+#define USBSS_MODE_CONTROL 0x1c
+#define USBSS_WAKEUP_CONFIG 0x30
+#define USBSS_WAKEUP_STAT 0x34
+#define USBSS_OVERRIDE_CONFIG 0x38
+#define USBSS_IRQ_MISC_STATUS_RAW 0x430
+#define USBSS_IRQ_MISC_STATUS 0x434
+#define USBSS_IRQ_MISC_ENABLE_SET 0x438
+#define USBSS_IRQ_MISC_ENABLE_CLR 0x43c
+#define USBSS_IRQ_MISC_EOI 0x440
+#define USBSS_INTR_TEST 0x490
+#define USBSS_VBUS_FILTER 0x614
+#define USBSS_VBUS_STAT 0x618
+#define USBSS_DEBUG_CFG 0x708
+#define USBSS_DEBUG_DATA 0x70c
+#define USBSS_HOST_HUB_CTRL 0x714
+
+/* PHY CONFIG register bits */
+#define USBSS_PHY_VBUS_SEL_MASK GENMASK(2, 1)
+#define USBSS_PHY_VBUS_SEL_SHIFT 1
+#define USBSS_PHY_LANE_REVERSE BIT(0)
+
+/* MODE CONTROL register bits */
+#define USBSS_MODE_VALID BIT(0)
+
+/* WAKEUP CONFIG register bits */
+#define USBSS_WAKEUP_CFG_OVERCURRENT_EN BIT(3)
+#define USBSS_WAKEUP_CFG_LINESTATE_EN BIT(2)
+#define USBSS_WAKEUP_CFG_SESSVALID_EN BIT(1)
+#define USBSS_WAKEUP_CFG_VBUSVALID_EN BIT(0)
+
+/* WAKEUP STAT register bits */
+#define USBSS_WAKEUP_STAT_OVERCURRENT BIT(4)
+#define USBSS_WAKEUP_STAT_LINESTATE BIT(3)
+#define USBSS_WAKEUP_STAT_SESSVALID BIT(2)
+#define USBSS_WAKEUP_STAT_VBUSVALID BIT(1)
+#define USBSS_WAKEUP_STAT_CLR BIT(0)
+
+/* IRQ_MISC_STATUS_RAW register bits */
+#define USBSS_IRQ_MISC_RAW_VBUSVALID BIT(22)
+#define USBSS_IRQ_MISC_RAW_SESSVALID BIT(20)
+
+/* IRQ_MISC_STATUS register bits */
+#define USBSS_IRQ_MISC_VBUSVALID BIT(22)
+#define USBSS_IRQ_MISC_SESSVALID BIT(20)
+
+/* IRQ_MISC_ENABLE_SET register bits */
+#define USBSS_IRQ_MISC_ENABLE_SET_VBUSVALID BIT(22)
+#define USBSS_IRQ_MISC_ENABLE_SET_SESSVALID BIT(20)
+
+/* IRQ_MISC_ENABLE_CLR register bits */
+#define USBSS_IRQ_MISC_ENABLE_CLR_VBUSVALID BIT(22)
+#define USBSS_IRQ_MISC_ENABLE_CLR_SESSVALID BIT(20)
+
+/* IRQ_MISC_EOI register bits */
+#define USBSS_IRQ_MISC_EOI_VECTOR BIT(0)
+
+/* VBUS_STAT register bits */
+#define USBSS_VBUS_STAT_SESSVALID BIT(2)
+#define USBSS_VBUS_STAT_VBUSVALID BIT(0)
+
+/* Mask for PHY PLL REFCLK */
+#define PHY_PLL_REFCLK_MASK GENMASK(3, 0)
+
+#define DWC3_AM62_AUTOSUSPEND_DELAY 100
+
+struct dwc3_data {
+ struct device *dev;
+ void __iomem *usbss;
+ struct clk *usb2_refclk;
+ struct work_struct work;
+ int vbus_irq;
+ int rate_code;
+ int connect;
+ struct regmap *syscon;
+ unsigned int offset;
+ unsigned int vbus_divider;
+};
+
+static const int dwc3_ti_rate_table[] = { /* in KHZ */
+ 9600,
+ 10000,
+ 12000,
+ 19200,
+ 20000,
+ 24000,
+ 25000,
+ 26000,
+ 38400,
+ 40000,
+ 58000,
+ 50000,
+ 52000,
+};
+
+static inline u32 dwc3_ti_readl(struct dwc3_data *data, u32 offset)
+{
+ return readl((data->usbss) + offset);
+}
+
+static inline void dwc3_ti_writel(struct dwc3_data *data, u32 offset, u32 value)
+{
+ writel(value, (data->usbss) + offset);
+}
+
+static void connect_detect_work(struct work_struct *work)
+{
+ struct dwc3_data *data =
+ container_of(work, struct dwc3_data, work);
+ u32 vbus_state, reg;
+ int connect = 0;
+
+ /* Read the status for VBUS valid register */
+ vbus_state = dwc3_ti_readl(data, USBSS_VBUS_STAT);
+ vbus_state &= USBSS_VBUS_STAT_VBUSVALID;
+
+ if (vbus_state)
+ connect = 1;
+
+ /* Set or clear mode valid bit based on connect or disconnect event */
+ if (data->connect != connect) {
+ reg = dwc3_ti_readl(data, USBSS_MODE_CONTROL);
+ if (connect)
+ reg |= USBSS_MODE_VALID;
+ else
+ reg &= ~USBSS_MODE_VALID;
+
+ dwc3_ti_writel(data, USBSS_MODE_CONTROL, reg);
+ data->connect = connect;
+ }
+}
+
+static irqreturn_t connect_detect_irq_handler(int irq, void *dev_id)
+{
+ struct dwc3_data *data = dev_id;
+ u32 reg;
+
+ /* Clear VBUS interrupt always to aviod queuing up redundant work items */
+ reg = dwc3_ti_readl(data, USBSS_IRQ_MISC_STATUS);
+ reg |= USBSS_IRQ_MISC_VBUSVALID;
+ dwc3_ti_writel(data, USBSS_IRQ_MISC_STATUS, reg);
+
+ queue_work(system_power_efficient_wq, &data->work);
+
+ reg = dwc3_ti_readl(data, USBSS_IRQ_MISC_EOI);
+ reg &= ~USBSS_IRQ_MISC_EOI_VECTOR;
+ dwc3_ti_writel(data, USBSS_IRQ_MISC_EOI, reg);
+ return IRQ_HANDLED;
+}
+
+static int dwc3_ti_vbus_irq_setup(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct dwc3_data *data = platform_get_drvdata(pdev);
+ int irq, ret;
+
+ /* Get the misc interrupt */
+ irq = platform_get_irq(pdev, 0);
+ if (irq < 0)
+ return irq;
+
+ ret = devm_request_irq(dev, irq, connect_detect_irq_handler, IRQF_SHARED,
+ dev_name(dev), data);
+ if (ret) {
+ dev_err(dev, "failed to required IRQ #%d-->%d\n",
+ irq, ret);
+ return ret;
+ }
+
+ data->vbus_irq = irq;
+
+ return 0;
+}
+
+static int phy_syscon_pll_refclk(struct dwc3_data *data)
+{
+ struct device *dev = data->dev;
+ struct device_node *node = dev->of_node;
+ struct of_phandle_args args;
+ struct regmap *syscon;
+ int ret;
+
+ syscon = syscon_regmap_lookup_by_phandle(node, "ti,syscon-phy-pll-refclk");
+ if (IS_ERR(syscon)) {
+ dev_err(dev, "unable to get ti,syscon-phy-pll-refclk regmap\n");
+ return PTR_ERR(syscon);
+ }
+
+ data->syscon = syscon;
+
+ ret = of_parse_phandle_with_fixed_args(node, "ti,syscon-phy-pll-refclk", 1,
+ 0, &args);
+ if (ret)
+ return ret;
+
+ data->offset = args.args[0];
+
+ ret = regmap_update_bits(data->syscon, data->offset, PHY_PLL_REFCLK_MASK, data->rate_code);
+ if (ret) {
+ dev_err(dev, "failed to set phy pll reference clock rate\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static void dwc3_ti_enable_irqs(struct dwc3_data *data)
+{
+ u32 reg;
+
+ /* enable VBUSVALID interrupt */
+ reg = dwc3_ti_readl(data, USBSS_IRQ_MISC_ENABLE_SET);
+ reg |= USBSS_IRQ_MISC_ENABLE_SET_VBUSVALID;
+ dwc3_ti_writel(data, USBSS_IRQ_MISC_ENABLE_SET, reg);
+}
+
+static void dwc3_ti_disable_irqs(struct dwc3_data *data)
+{
+ u32 reg;
+
+ /* disable VBUSVALID interrupt */
+ reg = dwc3_ti_readl(data, USBSS_IRQ_MISC_ENABLE_CLR);
+ reg |= USBSS_IRQ_MISC_ENABLE_CLR_VBUSVALID;
+ dwc3_ti_writel(data, USBSS_IRQ_MISC_ENABLE_CLR, reg);
+}
+
+static int dwc3_ti_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct device_node *node = pdev->dev.of_node;
+ struct dwc3_data *data;
+ int i, ret;
+ unsigned long rate;
+ u32 reg;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->dev = dev;
+ platform_set_drvdata(pdev, data);
+
+ data->usbss = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(data->usbss)) {
+ dev_err(dev, "can't map IOMEM resource\n");
+ return PTR_ERR(data->usbss);
+ }
+
+ data->usb2_refclk = devm_clk_get(dev, "ref");
+ if (IS_ERR(data->usb2_refclk)) {
+ dev_err(dev, "can't get usb2_refclk\n");
+ return PTR_ERR(data->usb2_refclk);
+ }
+
+ /* Calculate the rate code */
+ rate = clk_get_rate(data->usb2_refclk);
+ rate /= 1000; // To KHz
+ for (i = 0; i < ARRAY_SIZE(dwc3_ti_rate_table); i++) {
+ if (dwc3_ti_rate_table[i] == rate)
+ break;
+ }
+
+ if (i == ARRAY_SIZE(dwc3_ti_rate_table)) {
+ dev_err(dev, "unsupported usb2_refclk rate: %lu KHz\n", rate);
+ ret = -EINVAL;
+ goto err_clk_disable;
+ }
+
+ data->rate_code = i;
+
+ /* Read the syscon property and set the rate code */
+ ret = phy_syscon_pll_refclk(data);
+ if (ret)
+ goto err_clk_disable;
+
+ /* VBUS divider select */
+ data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider");
+ reg = dwc3_ti_readl(data, USBSS_PHY_CONFIG);
+ if (data->vbus_divider)
+ reg |= 1 << USBSS_PHY_VBUS_SEL_SHIFT;
+
+ dwc3_ti_writel(data, USBSS_PHY_CONFIG, reg);
+
+ /* Initialize a work queue */
+ ret = devm_work_autocancel(dev, &data->work, connect_detect_work);
+ if (ret)
+ goto err_clk_disable;
+
+ /* Read and set VBUS IRQ */
+ ret = dwc3_ti_vbus_irq_setup(pdev);
+ if (ret)
+ goto err_clk_disable;
+
+ pm_runtime_set_active(dev);
+ pm_runtime_enable(dev);
+ /*
+ * Don't ignore its dependencies with its children
+ */
+ pm_suspend_ignore_children(dev, false);
+ clk_prepare_enable(data->usb2_refclk);
+ pm_runtime_get_noresume(dev);
+
+ ret = of_platform_populate(node, NULL, NULL, dev);
+ if (ret) {
+ dev_err(dev, "failed to create dwc3 core: %d\n", ret);
+ goto err_pm_disable;
+ }
+
+ /* Enable vbus irq */
+ dwc3_ti_enable_irqs(data);
+
+ connect_detect_work(&data->work);
+
+ /* Setting up autosuspend */
+ pm_runtime_set_autosuspend_delay(dev, DWC3_AM62_AUTOSUSPEND_DELAY);
+ pm_runtime_use_autosuspend(dev);
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);
+ return 0;
+
+err_pm_disable:
+ clk_disable_unprepare(data->usb2_refclk);
+ pm_runtime_disable(dev);
+ pm_runtime_set_suspended(dev);
+err_clk_disable:
+ clk_put(data->usb2_refclk);
+ return ret;
+}
+
+static int dwc3_ti_remove_core(struct device *dev, void *c)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+
+ platform_device_unregister(pdev);
+ return 0;
+}
+
+static int dwc3_ti_remove(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct dwc3_data *data = platform_get_drvdata(pdev);
+ u32 reg;
+
+ dwc3_ti_disable_irqs(data);
+
+ device_for_each_child(dev, NULL, dwc3_ti_remove_core);
+
+ /* Clear mode valid bit */
+ reg = dwc3_ti_readl(data, USBSS_MODE_CONTROL);
+ reg &= ~USBSS_MODE_VALID;
+ dwc3_ti_writel(data, USBSS_MODE_CONTROL, reg);
+
+ pm_runtime_put_sync(dev);
+ clk_disable_unprepare(data->usb2_refclk);
+ pm_runtime_disable(dev);
+ pm_runtime_set_suspended(dev);
+
+ clk_put(data->usb2_refclk);
+ platform_set_drvdata(pdev, NULL);
+ return 0;
+}
+
+#ifdef CONFIG_PM
+static int dwc3_ti_suspend_common(struct device *dev)
+{
+ struct dwc3_data *data = dev_get_drvdata(dev);
+
+ /* disable irqs */
+ dwc3_ti_disable_irqs(data);
+
+ clk_disable_unprepare(data->usb2_refclk);
+
+ return 0;
+}
+
+static int dwc3_ti_resume_common(struct device *dev)
+{
+ struct dwc3_data *data = dev_get_drvdata(dev);
+
+ clk_prepare_enable(data->usb2_refclk);
+
+ /* Enable irqs */
+ dwc3_ti_enable_irqs(data);
+
+ return 0;
+}
+
+static UNIVERSAL_DEV_PM_OPS(dwc3_ti_pm_ops, dwc3_ti_suspend_common,
+ dwc3_ti_resume_common, NULL);
+
+#define DEV_PM_OPS (&dwc3_ti_pm_ops)
+#else
+#define DEV_PM_OPS NULL
+#endif /* CONFIG_PM */
+
+static const struct of_device_id dwc3_ti_of_match[] = {
+ { .compatible = "ti,am62-usb"},
+ {},
+};
+MODULE_DEVICE_TABLE(of, dwc3_ti_of_match);
+
+static struct platform_driver dwc3_ti_driver = {
+ .probe = dwc3_ti_probe,
+ .remove = dwc3_ti_remove,
+ .driver = {
+ .name = "dwc3-am62",
+ .pm = DEV_PM_OPS,
+ .of_match_table = dwc3_ti_of_match,
+ },
+};
+
+module_platform_driver(dwc3_ti_driver);
+
+MODULE_ALIAS("platform:dwc3-am62");
+MODULE_AUTHOR("Aswath Govindraju <a-govindraju@xxxxxx>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("DesignWare USB3 TI Glue Layer");
--
2.17.1