usb: dwc3: Add Exynos Specific Glue layer

Adds Exynos Specific Glue layer to support USB peripherals
on Samsung Exynos5 chips.

[ balbi@ti.com : prevent compilation of Exynos glue layer
	on platforms which don't provide clk API implementation ]

Signed-off-by: Anton Tikhomirov <av.tikhomirov@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

2 files changed, 164 insertions, 0 deletions

diff --git a/drivers/usb/dwc3/Makefile b/drivers/usb/dwc3/Makefile
index 900ae74357f1..d441fe4c180b 100644
--- a/drivers/usb/dwc3/Makefile
+++ b/drivers/usb/dwc3/Makefile
@@ -28,6 +28,19 @@ endif
 
 obj-$(CONFIG_USB_DWC3)		+= dwc3-omap.o
 
+##
+# REVISIT Samsung Exynos platform needs the clk API which isn't
+# defined on all architectures. If we allow dwc3-exynos.c compile
+# always we will fail the linking phase on those architectures
+# which don't provide clk api implementation and that's unnaceptable.
+#
+# When Samsung's platform start supporting pm_runtime, this check
+# for HAVE_CLK should be removed.
+##
+ifneq ($(CONFIG_HAVE_CLK),)
+	obj-$(CONFIG_USB_DWC3)		+= dwc3-exynos.o
+endif
+
 ifneq ($(CONFIG_PCI),)
 	obj-$(CONFIG_USB_DWC3)		+= dwc3-pci.o
 endif
diff --git a/drivers/usb/dwc3/dwc3-exynos.c b/drivers/usb/dwc3/dwc3-exynos.c
new file mode 100644
index 000000000000..d19030198086
--- /dev/null
+++ b/drivers/usb/dwc3/dwc3-exynos.c
@@ -0,0 +1,151 @@
+/**
+ * dwc3-exynos.c - Samsung EXYNOS DWC3 Specific Glue layer
+ *
+ * Copyright (c) 2012 Samsung Electronics Co., Ltd.
+ *		http://www.samsung.com
+ *
+ * Author: Anton Tikhomirov <av.tikhomirov@samsung.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/dwc3-exynos.h>
+#include <linux/dma-mapping.h>
+#include <linux/module.h>
+#include <linux/clk.h>
+
+#include "core.h"
+
+struct dwc3_exynos {
+	struct platform_device	*dwc3;
+	struct device		*dev;
+
+	struct clk		*clk;
+};
+
+static int __devinit dwc3_exynos_probe(struct platform_device *pdev)
+{
+	struct dwc3_exynos_data	*pdata = pdev->dev.platform_data;
+	struct platform_device	*dwc3;
+	struct dwc3_exynos	*exynos;
+	struct clk		*clk;
+
+	int			devid;
+	int			ret = -ENOMEM;
+
+	exynos = kzalloc(sizeof(*exynos), GFP_KERNEL);
+	if (!exynos) {
+		dev_err(&pdev->dev, "not enough memory\n");
+		goto err0;
+	}
+
+	platform_set_drvdata(pdev, exynos);
+
+	devid = dwc3_get_device_id();
+	if (devid < 0)
+		goto err1;
+
+	dwc3 = platform_device_alloc("dwc3", devid);
+	if (!dwc3) {
+		dev_err(&pdev->dev, "couldn't allocate dwc3 device\n");
+		goto err2;
+	}
+
+	clk = clk_get(&pdev->dev, "usbdrd30");
+	if (IS_ERR(clk)) {
+		dev_err(&pdev->dev, "couldn't get clock\n");
+		ret = -EINVAL;
+		goto err3;
+	}
+
+	dma_set_coherent_mask(&dwc3->dev, pdev->dev.coherent_dma_mask);
+
+	dwc3->dev.parent = &pdev->dev;
+	dwc3->dev.dma_mask = pdev->dev.dma_mask;
+	dwc3->dev.dma_parms = pdev->dev.dma_parms;
+	exynos->dwc3	= dwc3;
+	exynos->dev	= &pdev->dev;
+	exynos->clk	= clk;
+
+	clk_enable(exynos->clk);
+
+	/* PHY initialization */
+	if (!pdata) {
+		dev_dbg(&pdev->dev, "missing platform data\n");
+	} else {
+		if (pdata->phy_init)
+			pdata->phy_init(pdev, pdata->phy_type);
+	}
+
+	ret = platform_device_add_resources(dwc3, pdev->resource,
+			pdev->num_resources);
+	if (ret) {
+		dev_err(&pdev->dev, "couldn't add resources to dwc3 device\n");
+		goto err4;
+	}
+
+	ret = platform_device_add(dwc3);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to register dwc3 device\n");
+		goto err4;
+	}
+
+	return 0;
+
+err4:
+	if (pdata && pdata->phy_exit)
+		pdata->phy_exit(pdev, pdata->phy_type);
+
+	clk_disable(clk);
+	clk_put(clk);
+err3:
+	platform_device_put(dwc3);
+err2:
+	dwc3_put_device_id(devid);
+err1:
+	kfree(exynos);
+err0:
+	return ret;
+}
+
+static int __devexit dwc3_exynos_remove(struct platform_device *pdev)
+{
+	struct dwc3_exynos	*exynos = platform_get_drvdata(pdev);
+	struct dwc3_exynos_data *pdata = pdev->dev.platform_data;
+
+	platform_device_unregister(exynos->dwc3);
+
+	dwc3_put_device_id(exynos->dwc3->id);
+
+	if (pdata && pdata->phy_exit)
+		pdata->phy_exit(pdev, pdata->phy_type);
+
+	clk_disable(exynos->clk);
+	clk_put(exynos->clk);
+
+	kfree(exynos);
+
+	return 0;
+}
+
+static struct platform_driver dwc3_exynos_driver = {
+	.probe		= dwc3_exynos_probe,
+	.remove		= __devexit_p(dwc3_exynos_remove),
+	.driver		= {
+		.name	= "exynos-dwc3",
+	},
+};
+
+module_platform_driver(dwc3_exynos_driver);
+
+MODULE_ALIAS("platform:exynos-dwc3");
+MODULE_AUTHOR("Anton Tikhomirov <av.tikhomirov@samsung.com>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("DesignWare USB3 EXYNOS Glue Layer");