/**
* dwc3-keystone.c - Keystone Specific Glue layer
*
* Copyright (C) 2010-2013 Texas Instruments Incorporated - http://www.ti.com
*
* Author: WingMan Kwok <w-kwok2@ti.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 of
* the License 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/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>
/* USBSS register offsets */
#define USBSS_REVISION 0x0000
#define USBSS_SYSCONFIG 0x0010
#define USBSS_IRQ_EOI 0x0018
#define USBSS_IRQSTATUS_RAW_0 0x0020
#define USBSS_IRQSTATUS_0 0x0024
#define USBSS_IRQENABLE_SET_0 0x0028
#define USBSS_IRQENABLE_CLR_0 0x002c
/* IRQ register bits */
#define USBSS_IRQ_EOI_LINE(n) BIT(n)
#define USBSS_IRQ_EVENT_ST BIT(0)
#define USBSS_IRQ_COREIRQ_EN BIT(0)
#define USBSS_IRQ_COREIRQ_CLR BIT(0)
static u64 kdwc3_dma_mask;
struct dwc3_keystone {
struct device *dev;
struct clk *clk;
void __iomem *usbss;
};
static inline u32 kdwc3_readl(void __iomem *base, u32 offset)
{
return readl(base + offset);
}
static inline void kdwc3_writel(void __iomem *base, u32 offset, u32 value)
{
writel(value, base + offset);
}
static void kdwc3_enable_irqs(struct dwc3_keystone *kdwc)
{
u32 val;
val = kdwc3_readl(kdwc->usbss, USBSS_IRQENABLE_SET_0);
val |= USBSS_IRQ_COREIRQ_EN;
kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, val);
}
static void kdwc3_disable_irqs(struct dwc3_keystone *kdwc)
{
u32 val;
val = kdwc3_readl(kdwc->usbss, USBSS_IRQENABLE_SET_0);
val &= ~USBSS_IRQ_COREIRQ_EN;
kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, val);
}
static irqreturn_t dwc3_keystone_interrupt(int irq, void *_kdwc)
{
struct dwc3_keystone *kdwc = _kdwc;
kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_CLR_0, USBSS_IRQ_COREIRQ_CLR);
kdwc3_writel(kdwc->usbss, USBSS_IRQSTATUS_0, USBSS_IRQ_EVENT_ST);
kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, USBSS_IRQ_COREIRQ_EN);
kdwc3_writel(kdwc->usbss, USBSS_IRQ_EOI, USBSS_IRQ_EOI_LINE(0));
return IRQ_HANDLED;
}
static int kdwc3_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *node = pdev->dev.of_node;
struct dwc3_keystone *kdwc;
struct resource *res;
int error, irq;
kdwc = devm_kzalloc(dev, sizeof(*kdwc), GFP_KERNEL);
if (!kdwc)
return -ENOMEM;
platform_set_drvdata(pdev, kdwc);
kdwc->dev = dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
kdwc->usbss = devm_ioremap_resource(dev, res);
if (IS_ERR(kdwc->usbss))
return PTR_ERR(kdwc->usbss);
kdwc3_dma_mask = dma_get_mask(dev);
dev->dma_mask = &kdwc3_dma_mask;
kdwc->clk = devm_clk_get(kdwc->dev, "usb");
error = clk_prepare_enable(kdwc->clk);
if (error < 0) {
dev_dbg(kdwc->dev, "unable to enable usb clock, err %d\n",
error);
return error;
}
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "missing irq\n");
goto err_irq;
}
error = devm_request_irq(dev, irq, dwc3_keystone_interrupt, IRQF_SHARED,
dev_name(dev), kdwc);
if (error) {
dev_err(dev, "failed to request IRQ #%d --> %d\n",
irq, error);
goto err_irq;
}
kdwc3_enable_irqs(kdwc);
error = of_platform_populate(node, NULL, NULL, dev);
if (error) {
dev_err(&pdev->dev, "failed to create dwc3 core\n");
goto err_core;
}
return 0;
err_core:
kdwc3_disable_irqs(kdwc);
err_irq:
clk_disable_unprepare(kdwc->clk);
return error;
}
static int kdwc3_remove_core(struct device *dev, void *c)
{
struct platform_device *pdev = to_platform_device(dev);
platform_device_unregister(pdev);
return 0;
}
static int kdwc3_remove(struct platform_device *pdev)
{
struct dwc3_keystone *kdwc = platform_get_drvdata(pdev);
kdwc3_disable_irqs(kdwc);
device_for_each_child(&pdev->dev, NULL, kdwc3_remove_core);
clk_disable_unprepare(kdwc->clk);
platform_set_drvdata(pdev, NULL);
return 0;
}
static const struct of_device_id kdwc3_of_match[] = {
{ .compatible = "ti,keystone-dwc3", },
{},
};
MODULE_DEVICE_TABLE(of, kdwc3_of_match);
static struct platform_driver kdwc3_driver = {
.probe = kdwc3_probe,
.remove = kdwc3_remove,
.driver = {
.name = "keystone-dwc3",
.of_match_table = kdwc3_of_match,
},
};
module_platform_driver(kdwc3_driver);
MODULE_ALIAS("platform:keystone-dwc3");
MODULE_AUTHOR("WingMan Kwok <w-kwok2@ti.com>");
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("DesignWare USB3 KEYSTONE Glue Layer");
