[PATCH 2/2] usb: cdns3: Add TI specific wrapper driver

[Roger Quadros]

The J721e platform comes with 2 Cadence USB3 controller
instances. This driver supports the TI specific wrapper
on this platform.

Signed-off-by: Roger Quadros <rogerq@xxxxxx>
Signed-off-by: Sekhar Nori <nsekhar@xxxxxx>
---
 drivers/usb/cdns3/Kconfig    |  10 ++
 drivers/usb/cdns3/Makefile   |   1 +
 drivers/usb/cdns3/cdns3-ti.c | 244 +++++++++++++++++++++++++++++++++++
 3 files changed, 255 insertions(+)
 create mode 100644 drivers/usb/cdns3/cdns3-ti.c

diff --git a/drivers/usb/cdns3/Kconfig b/drivers/usb/cdns3/Kconfig
index d0331613a355..2a1e89d12ed9 100644
--- a/drivers/usb/cdns3/Kconfig
+++ b/drivers/usb/cdns3/Kconfig
@@ -43,4 +43,14 @@ config USB_CDNS3_PCI_WRAP
 	  If you choose to build this driver as module it will
 	  be dynamically linked and module will be called cdns3-pci.ko
 
+config USB_CDNS3_TI
+	tristate "Cadence USB3 support on TI platforms"
+	depends on ARCH_K3 || COMPILE_TEST
+	default USB_CDNS3
+	help
+	  Say 'Y' or 'M' here if you are building for Texas Instruments
+	  platforms that contain Cadence USB3 controller core.
+
+	  e.g. J721e.
+
 endif
diff --git a/drivers/usb/cdns3/Makefile b/drivers/usb/cdns3/Makefile
index a703547350bb..948e6b88d1a9 100644
--- a/drivers/usb/cdns3/Makefile
+++ b/drivers/usb/cdns3/Makefile
@@ -14,3 +14,4 @@ endif
 cdns3-$(CONFIG_USB_CDNS3_HOST)		+= host.o
 
 obj-$(CONFIG_USB_CDNS3_PCI_WRAP)	+= cdns3-pci-wrap.o
+obj-$(CONFIG_USB_CDNS3_TI)		+= cdns3-ti.o
diff --git a/drivers/usb/cdns3/cdns3-ti.c b/drivers/usb/cdns3/cdns3-ti.c
new file mode 100644
index 000000000000..7447f5fcbe64
--- /dev/null
+++ b/drivers/usb/cdns3/cdns3-ti.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0
+/**
+ * cdns_ti-ti.c - TI specific Glue layer for Cadence USB Controller
+ *
+ * Copyright (C) 2019 Texas Instruments Incorporated - http://www.ti.com
+ */
+
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/dma-mapping.h>
+#include <linux/io.h>
+#include <linux/of_platform.h>
+#include <linux/pm_runtime.h>
+
+/* USB Wrapper register offsets */
+#define USBSS_PID		0x0
+#define	USBSS_W1		0x4
+#define USBSS_STATIC_CONFIG	0x8
+#define USBSS_PHY_TEST		0xc
+#define	USBSS_DEBUG_CTRL	0x10
+#define	USBSS_DEBUG_INFO	0x14
+#define	USBSS_DEBUG_LINK_STATE	0x18
+#define	USBSS_DEVICE_CTRL	0x1c
+
+/* Wrapper 1 register bits */
+#define USBSS_W1_PWRUP_RST		BIT(0)
+#define USBSS_W1_OVERCURRENT_SEL	BIT(8)
+#define USBSS_W1_MODESTRAP_SEL		BIT(9)
+#define USBSS_W1_OVERCURRENT		BIT(16)
+#define USBSS_W1_MODESTRAP_MASK		GENMASK(18, 17)
+#define USBSS_W1_MODESTRAP_SHIFT	17
+#define USBSS_W1_USB2_ONLY		BIT(19)
+
+/* Static config register bits */
+#define USBSS1_STATIC_PLL_REF_SEL_MASK	GENMASK(8, 5)
+#define USBSS1_STATIC_PLL_REF_SEL_SHIFT	5
+#define USBSS1_STATIC_LOOPBACK_MODE_MASK	GENMASK(4, 3)
+#define USBSS1_STATIC_LOOPBACK_MODE_SHIFT	3
+#define USBSS1_STATIC_VBUS_SEL_MASK	GENMASK(2, 1)
+#define USBSS1_STATIC_VBUS_SEL_SHIFT	1
+#define USBSS1_STATIC_LANE_REVERSE	BIT(0)
+
+/* Modestrap modes */
+enum modestrap_mode { USBSS_MODESTRAP_MODE_NONE,
+		      USBSS_MODESTRAP_MODE_HOST,
+		      USBSS_MODESTRAP_MODE_PERIPHERAL};
+
+struct cdns_ti {
+	struct device *dev;
+	void __iomem *usbss;
+	int usb2_only:1;
+	int vbus_divider:1;
+	struct clk *usb2_refclk;
+	struct clk *lpm_clk;
+};
+
+static const int cdns_ti_rate_table[] = {	/* in KHZ */
+	9600,
+	10000,
+	12000,
+	19200,
+	20000,
+	24000,
+	25000,
+	26000,
+	38400,
+	40000,
+	58000,
+	50000,
+	52000,
+};
+
+static inline u32 cdns_ti_readl(struct cdns_ti *data, u32 offset)
+{
+	return readl(data->usbss + offset);
+}
+
+static inline void cdns_ti_writel(struct cdns_ti *data, u32 offset, u32 value)
+{
+	writel(value, data->usbss + offset);
+}
+
+static int cdns_ti_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *node = pdev->dev.of_node;
+	struct cdns_ti *data;
+	struct resource	*res;
+	int error;
+	u32 reg;
+	int modestrap_mode;
+	int rate_code, i;
+	unsigned long rate;
+
+	data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, data);
+
+	data->dev = dev;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	data->usbss = devm_ioremap_resource(dev, res);
+	if (IS_ERR(data->usbss))
+		return PTR_ERR(data->usbss);
+
+	data->usb2_refclk = devm_clk_get(dev, "usb2_refclk");
+	if (IS_ERR(data->usb2_refclk)) {
+		dev_err(dev, "can't get usb2_refclk\n");
+		return PTR_ERR(data->usb2_refclk);
+	}
+
+	data->lpm_clk = devm_clk_get(dev, "lpm_clk");
+	if (IS_ERR(data->lpm_clk)) {
+		dev_err(dev, "can't get lpm_clk\n");
+		return PTR_ERR(data->lpm_clk);
+	}
+
+	rate = clk_get_rate(data->usb2_refclk);
+	rate /= 1000;	/* To KHz */
+	for (i = 0; i < ARRAY_SIZE(cdns_ti_rate_table); i++) {
+		if (cdns_ti_rate_table[i] == rate)
+			break;
+	}
+
+	if (i == ARRAY_SIZE(cdns_ti_rate_table)) {
+		dev_err(dev, "unsupported usb2_refclk rate: %lu KHz\n", rate);
+		return -EINVAL;
+	}
+
+	rate_code = i;
+
+	pm_runtime_enable(dev);
+	error = pm_runtime_get_sync(dev);
+	if (error < 0) {
+		dev_err(dev, "pm_runtime_get_sync failed: %d\n", error);
+		goto err_get;
+	}
+
+	/* assert RESET */
+	reg = cdns_ti_readl(data, USBSS_W1);
+	reg &= ~USBSS_W1_PWRUP_RST;
+	cdns_ti_writel(data, USBSS_W1, reg);
+
+	/* set static config */
+	reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
+	reg &= ~USBSS1_STATIC_PLL_REF_SEL_MASK;
+	reg |= rate_code << USBSS1_STATIC_PLL_REF_SEL_SHIFT;
+
+	reg &= ~USBSS1_STATIC_VBUS_SEL_MASK;
+	data->vbus_divider = device_property_read_bool(dev, "ti,vbus-divider");
+	if (data->vbus_divider)
+		reg |= 1 << USBSS1_STATIC_VBUS_SEL_SHIFT;
+
+	cdns_ti_writel(data, USBSS_STATIC_CONFIG, reg);
+	reg = cdns_ti_readl(data, USBSS_STATIC_CONFIG);
+
+	/* set USB2_ONLY mode if requested */
+	reg = cdns_ti_readl(data, USBSS_W1);
+	data->usb2_only = device_property_read_bool(dev, "ti,usb2-only");
+	if (data->usb2_only)
+		reg |= USBSS_W1_USB2_ONLY;
+
+	/* set modestrap  */
+	if (device_property_read_bool(dev, "ti,modestrap-host"))
+		modestrap_mode = USBSS_MODESTRAP_MODE_HOST;
+	else if (device_property_read_bool(dev, "ti,modestrap-peripheral"))
+		modestrap_mode = USBSS_MODESTRAP_MODE_PERIPHERAL;
+	else
+		modestrap_mode = USBSS_MODESTRAP_MODE_NONE;
+
+	reg |= USBSS_W1_MODESTRAP_SEL;
+	reg &= ~USBSS_W1_MODESTRAP_MASK;
+	reg |= modestrap_mode << USBSS_W1_MODESTRAP_SHIFT;
+	cdns_ti_writel(data, USBSS_W1, reg);
+
+	/* de-assert RESET */
+	reg |= USBSS_W1_PWRUP_RST;
+	cdns_ti_writel(data, USBSS_W1, reg);
+
+	error = of_platform_populate(node, NULL, NULL, dev);
+	if (error) {
+		dev_err(dev, "failed to create children: %d\n", error);
+		goto err;
+	}
+
+	return 0;
+
+err:
+	pm_runtime_put_sync(data->dev);
+err_get:
+	pm_runtime_disable(data->dev);
+
+	return error;
+}
+
+static int cdns_ti_remove_core(struct device *dev, void *c)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+
+	platform_device_unregister(pdev);
+
+	return 0;
+}
+
+static int cdns_ti_remove(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+
+	device_for_each_child(dev, NULL, cdns_ti_remove_core);
+	pm_runtime_put_sync(dev);
+	pm_runtime_disable(dev);
+
+	platform_set_drvdata(pdev, NULL);
+
+	return 0;
+}
+
+static const struct of_device_id cdns_ti_of_match[] = {
+	{ .compatible = "ti,j721e-usb", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, cdns_ti_of_match);
+
+static struct platform_driver cdns_ti_driver = {
+	.probe		= cdns_ti_probe,
+	.remove		= cdns_ti_remove,
+	.driver		= {
+		.name	= "cdns3-ti",
+		.of_match_table	= cdns_ti_of_match,
+	},
+};
+
+module_platform_driver(cdns_ti_driver);
+
+MODULE_ALIAS("platform:cdns3-ti");
+MODULE_AUTHOR("Roger Quadros <rogerq@xxxxxx>");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Cadence USB3 TI Glue Layer");
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