[PATCH v4 0/2] AM62: Add support for AM62 USB wrapper driver

[PATCH v4 0/2] AM62: Add support for AM62 USB wrapper driver

[Aswath Govindraju]

The following series of patches add support for AM62 USB wrapper driver
and its corresponding bindings.

changes since v3:
- Removed the VBUS_VALID interrupt servicing as mode valid bit
  need not be switched based on the connect/disconnect event.
  The mode valid bit is being set during probe and cleared
  during remove
- As VBUS_VALID interrupt is not being used, removed the interrupts
  property from the bindings. As there is change in the dt-bindings
  I did not pick the reviewed-by tags from the earlier version of
  the series.

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.

changes since v1:
- Fixed the error with dev_pm_ops uninitialization, in patch 2.
  This was reported by kernel test bot
- In patch 1, made correction in grammer of clocks property description
  and added maxItems in the interrupts property based on comments
  received from Roger
- In patch 1, corrected the title, fixed the description of
  ti,syscon-phy-pll-refclk, added pattern properties and child node
  in the example based on the comments from Krzysztof. 

Aswath Govindraju (2):
  dt-bindings: usb: Add documentation for AM62 USB Wrapper module
  drivers: usb: dwc3: Add AM62 USB wrapper driver

 .../devicetree/bindings/usb/ti,am62-usb.yaml  | 103 ++++++
 drivers/usb/dwc3/Kconfig                      |   9 +
 drivers/usb/dwc3/Makefile                     |   1 +
 drivers/usb/dwc3/dwc3-am62.c                  | 332 ++++++++++++++++++
 4 files changed, 445 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/usb/ti,am62-usb.yaml
 create mode 100644 drivers/usb/dwc3/dwc3-am62.c

-- 
2.17.1

[PATCH v4 1/2] dt-bindings: usb: Add documentation for AM62 USB Wrapper module

[Aswath Govindraju]

Add bindings for the TI's AM62 wrapper module for the Synopsys USBSS-DRD
controller.

Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
---

Changes since v3:
- As VBUS_VALID interrupt is not being used, removed the interrupts
  property from the bindings. As there is change in the properties
  I did not pick the reviewed-by tags from the earlier version of
  the series.

 .../devicetree/bindings/usb/ti,am62-usb.yaml  | 103 ++++++++++++++++++
 1 file changed, 103 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/usb/ti,am62-usb.yaml

diff --git a/Documentation/devicetree/bindings/usb/ti,am62-usb.yaml b/Documentation/devicetree/bindings/usb/ti,am62-usb.yaml
new file mode 100644
index 000000000000..d25fc708e32c
--- /dev/null
+++ b/Documentation/devicetree/bindings/usb/ti,am62-usb.yaml
@@ -0,0 +1,103 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/usb/ti,am62-usb.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TI's AM62 wrapper module for the Synopsys USBSS-DRD controller
+
+maintainers:
+  - Aswath Govindraju <a-govindraju@ti.com>
+
+properties:
+  compatible:
+    const: ti,am62-usb
+
+  reg:
+    maxItems: 1
+
+  ranges: true
+
+  power-domains:
+    description:
+      PM domain provider node and an args specifier containing
+      the USB ISO device id value. See,
+      Documentation/devicetree/bindings/soc/ti/sci-pm-domain.yaml
+    maxItems: 1
+
+  clocks:
+    description: Clock phandle to usb2_refclk
+    maxItems: 1
+
+  clock-names:
+    items:
+      - const: ref
+
+  ti,vbus-divider:
+    description:
+      Should be present if USB VBUS line is connected to the
+      VBUS pin of the SoC via a 1/3 voltage divider.
+    type: boolean
+
+  ti,syscon-phy-pll-refclk:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    items:
+      - items:
+          - description: Phandle to the SYSCON entry
+          - description: USB phy control register offset within SYSCON
+    description:
+      Specifier for conveying frequency of ref clock input, for the
+      operation of USB2PHY.
+
+  '#address-cells':
+    const: 2
+
+  '#size-cells':
+    const: 2
+
+patternProperties:
+  "^usb@[0-9a-f]+$":
+    $ref: snps,dwc3.yaml#
+    description: Required child node
+
+required:
+  - compatible
+  - reg
+  - power-domains
+  - clocks
+  - clock-names
+  - ti,syscon-phy-pll-refclk
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/soc/ti,sci_pm_domain.h>
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/gpio/gpio.h>
+
+    bus {
+      #address-cells = <2>;
+      #size-cells = <2>;
+
+      usbss1: usb@f910000 {
+        compatible = "ti,am62-usb";
+        reg = <0x00 0x0f910000 0x00 0x800>;
+        clocks = <&k3_clks 162 3>;
+        clock-names = "ref";
+        ti,syscon-phy-pll-refclk = <&wkup_conf 0x4018>;
+        power-domains = <&k3_pds 179 TI_SCI_PD_EXCLUSIVE>;
+        #address-cells = <2>;
+        #size-cells = <2>;
+
+        usb@31100000 {
+          compatible = "snps,dwc3";
+          reg =<0x00 0x31100000 0x00 0x50000>;
+          interrupts = <GIC_SPI 226 IRQ_TYPE_LEVEL_HIGH>, /* irq.0 */
+                       <GIC_SPI 226 IRQ_TYPE_LEVEL_HIGH>; /* irq.0 */
+          interrupt-names = "host", "peripheral";
+          maximum-speed = "high-speed";
+          dr_mode = "otg";
+        };
+      };
+    };
-- 
2.17.1

[PATCH v4 2/2] drivers: usb: dwc3: Add AM62 USB wrapper driver

[Aswath Govindraju]

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@ti.com>
---

Changes since v3:
- Removed the VBUS_VALID interrupt servicing as mode valid bit
  need not be switched based on the connect/disconnect event.
  The mode valid bit is being set during probe and cleared
  during remove

 drivers/usb/dwc3/Kconfig     |   9 +
 drivers/usb/dwc3/Makefile    |   1 +
 drivers/usb/dwc3/dwc3-am62.c | 332 +++++++++++++++++++++++++++++++++++
 3 files changed, 342 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..730f2be46ef5
--- /dev/null
+++ b/drivers/usb/dwc3/dwc3-am62.c
@@ -0,0 +1,332 @@
+// 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/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.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/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;
+	int rate_code;
+	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 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 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);
+
+	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;
+	}
+
+	/* Set mode valid bit to indicate role is valid */
+	reg = dwc3_ti_readl(data, USBSS_MODE_CONTROL);
+	reg |= USBSS_MODE_VALID;
+	dwc3_ti_writel(data, USBSS_MODE_CONTROL, reg);
+
+	/* 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;
+
+	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);
+
+	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);
+
+	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@ti.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("DesignWare USB3 TI Glue Layer");
-- 
2.17.1

Re: [PATCH v4 1/2] dt-bindings: usb: Add documentation for AM62 USB Wrapper module

[Rob Herring]

On Thu, 14 Apr 2022 16:02:08 +0530, Aswath Govindraju wrote:
> Add bindings for the TI's AM62 wrapper module for the Synopsys USBSS-DRD
> controller.
> 
> Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
> ---
> 
> Changes since v3:
> - As VBUS_VALID interrupt is not being used, removed the interrupts
>   property from the bindings. As there is change in the properties
>   I did not pick the reviewed-by tags from the earlier version of
>   the series.
> 
>  .../devicetree/bindings/usb/ti,am62-usb.yaml  | 103 ++++++++++++++++++
>  1 file changed, 103 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/usb/ti,am62-usb.yaml
> 

Reviewed-by: Rob Herring <robh@kernel.org>