[PATCH v6 3/3] usb: dwc3: Add Qualcomm DWC3 glue layer driver

["Ivan T. Ivanov" <iivanov@mm-sol.com>]

From: "Ivan T. Ivanov" <iivanov@mm-sol.com>

DWC3 glue layer is hardware layer around Synopsys DesignWare
USB3 core. Its purpose is to supply Synopsys IP with required
clocks, voltages and interface it with the rest of the SoC.

Signed-off-by: Ivan T. Ivanov <iivanov@mm-sol.com>
---
 drivers/usb/dwc3/Kconfig    |    8 +++
 drivers/usb/dwc3/Makefile   |    1 +
 drivers/usb/dwc3/dwc3-msm.c |  168 +++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 177 insertions(+)
 create mode 100644 drivers/usb/dwc3/dwc3-msm.c

diff --git a/drivers/usb/dwc3/Kconfig b/drivers/usb/dwc3/Kconfig
index 70fc430..4c7b5a4 100644
--- a/drivers/usb/dwc3/Kconfig
+++ b/drivers/usb/dwc3/Kconfig
@@ -59,6 +59,14 @@ config USB_DWC3_EXYNOS
 	  Recent Exynos5 SoCs ship with one DesignWare Core USB3 IP inside,
 	  say 'Y' or 'M' if you have one such device.
 
+config USB_DWC3_MSM
+       tristate "Qualcomm MSM/APQ Platforms"
+       default USB_DWC3
+       select USB_MSM_DWC3_PHYS
+       help
+         Recent Qualcomm SoCs ship with one DesignWare Core USB3 IP inside,
+         say 'Y' or 'M' if you have one such device.
+
 config USB_DWC3_PCI
 	tristate "PCIe-based Platforms"
 	depends on PCI
diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
index dd17601..a90de66 100644
--- a/drivers/usb/dwc3/Makefile
+++ b/drivers/usb/dwc3/Makefile
@@ -31,4 +31,5 @@ endif
 
 obj-$(CONFIG_USB_DWC3_OMAP)		+= dwc3-omap.o
 obj-$(CONFIG_USB_DWC3_EXYNOS)		+= dwc3-exynos.o
+obj-$(CONFIG_USB_DWC3_MSM)		+= dwc3-msm.o
 obj-$(CONFIG_USB_DWC3_PCI)		+= dwc3-pci.o
diff --git a/drivers/usb/dwc3/dwc3-msm.c b/drivers/usb/dwc3/dwc3-msm.c
new file mode 100644
index 0000000..1d73f92
--- /dev/null
+++ b/drivers/usb/dwc3/dwc3-msm.c
@@ -0,0 +1,168 @@
+/* Copyright (c) 2013, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+#include <linux/usb/phy.h>
+
+struct dwc3_msm {
+	struct device		*dev;
+
+	struct clk		*core_clk;
+	struct clk		*iface_clk;
+	struct clk		*sleep_clk;
+	struct clk		*utmi_clk;
+
+	struct regulator	*gdsc;
+};
+
+static int dwc3_msm_probe(struct platform_device *pdev)
+{
+	struct device_node *node = pdev->dev.of_node;
+	struct dwc3_msm *mdwc;
+	struct resource *res;
+	void __iomem *tcsr;
+	int ret = 0;
+
+	mdwc = devm_kzalloc(&pdev->dev, sizeof(*mdwc), GFP_KERNEL);
+	if (!mdwc)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, mdwc);
+
+	mdwc->dev = &pdev->dev;
+
+	mdwc->gdsc = devm_regulator_get(mdwc->dev, "gdsc");
+
+	mdwc->core_clk = devm_clk_get(mdwc->dev, "core");
+	if (IS_ERR(mdwc->core_clk)) {
+		dev_dbg(mdwc->dev, "failed to get core clock\n");
+		return PTR_ERR(mdwc->core_clk);
+	}
+
+	mdwc->iface_clk = devm_clk_get(mdwc->dev, "iface");
+	if (IS_ERR(mdwc->iface_clk)) {
+		dev_dbg(mdwc->dev, "failed to get iface clock\n");
+		return PTR_ERR(mdwc->iface_clk);
+	}
+
+	mdwc->sleep_clk = devm_clk_get(mdwc->dev, "sleep");
+	if (IS_ERR(mdwc->sleep_clk)) {
+		dev_dbg(mdwc->dev, "failed to get sleep clock\n");
+		return  PTR_ERR(mdwc->sleep_clk);
+	}
+
+	mdwc->utmi_clk = devm_clk_get(mdwc->dev, "utmi");
+	if (IS_ERR(mdwc->utmi_clk)) {
+		dev_dbg(mdwc->dev, "failed to get utmi clock\n");
+		return  PTR_ERR(mdwc->utmi_clk);
+	}
+
+	if (!IS_ERR(mdwc->gdsc)) {
+		ret = regulator_enable(mdwc->gdsc);
+		if (ret)
+			dev_err(mdwc->dev, "cannot enable gdsc\n");
+	}
+
+	/*
+	 * DWC3 Core requires its CORE CLK (aka master / bus clk) to
+	 * run at 125Mhz in SSUSB mode and >60MHZ for HSUSB mode.
+	 */
+	clk_set_rate(mdwc->core_clk, 125000000);
+	clk_prepare_enable(mdwc->core_clk);
+	clk_prepare_enable(mdwc->iface_clk);
+	clk_prepare_enable(mdwc->sleep_clk);
+	clk_prepare_enable(mdwc->utmi_clk);
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	tcsr = devm_ioremap_resource(mdwc->dev, res);
+	if (!tcsr) {
+		ret = PTR_ERR(tcsr);
+		goto dis_clks;
+	}
+
+	/*
+	 * Primary USB port is shared between USB2 and USB3 controllers.
+	 * By default this port is routed to USB2. Select primary port for
+	 * USB3, this will automatically move USB2 to secondary port.
+	 */
+	writel(0x1, tcsr);
+
+	ret = of_platform_populate(node, NULL, NULL, mdwc->dev);
+	if (ret) {
+		dev_dbg(mdwc->dev, "failed to add create dwc3 core\n");
+		writel(0x0, tcsr);
+		goto dis_clks;
+	}
+
+	return 0;
+
+dis_clks:
+	clk_disable_unprepare(mdwc->utmi_clk);
+	clk_disable_unprepare(mdwc->sleep_clk);
+	clk_disable_unprepare(mdwc->iface_clk);
+	clk_disable_unprepare(mdwc->core_clk);
+	if (!IS_ERR(mdwc->gdsc)) {
+		ret = regulator_disable(mdwc->gdsc);
+		if (ret)
+			dev_dbg(mdwc->dev, "cannot disable gdsc\n");
+	}
+
+	return ret;
+}
+
+static int dwc3_msm_remove(struct platform_device *pdev)
+{
+	struct dwc3_msm	*mdwc = platform_get_drvdata(pdev);
+	int ret;
+
+	clk_disable_unprepare(mdwc->utmi_clk);
+	clk_disable_unprepare(mdwc->sleep_clk);
+	clk_disable_unprepare(mdwc->iface_clk);
+	clk_disable_unprepare(mdwc->core_clk);
+
+	if (!IS_ERR(mdwc->gdsc)) {
+		ret = regulator_disable(mdwc->gdsc);
+		if (ret)
+			dev_dbg(mdwc->dev, "cannot disable gdsc\n");
+	}
+
+	return 0;
+}
+
+static const struct of_device_id of_dwc3_match[] = {
+	{ .compatible = "qcom,dwc3" },
+	{ /* Sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, of_dwc3_match);
+
+static struct platform_driver dwc3_msm_driver = {
+	.probe		= dwc3_msm_probe,
+	.remove		= dwc3_msm_remove,
+	.driver		= {
+		.name	= "msm-dwc3",
+		.owner	= THIS_MODULE,
+		.of_match_table	= of_dwc3_match,
+	},
+};
+
+module_platform_driver(dwc3_msm_driver);
+
+MODULE_ALIAS("platform:msm-dwc3");
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("DesignWare USB3 MSM Glue Layer");
-- 
1.7.9.5