linux/drivers/usb/dwc3/dwc3-keystone.c
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   1/**
   2 * dwc3-keystone.c - Keystone Specific Glue layer
   3 *
   4 * Copyright (C) 2010-2013 Texas Instruments Incorporated - http://www.ti.com
   5 *
   6 * Author: WingMan Kwok <w-kwok2@ti.com>
   7 *
   8 * This program is free software: you can redistribute it and/or modify
   9 * it under the terms of the GNU General Public License version 2  of
  10 * the License as published by the Free Software Foundation.
  11 *
  12 * This program is distributed in the hope that it will be useful,
  13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 * GNU General Public License for more details.
  16 */
  17
  18#include <linux/clk.h>
  19#include <linux/module.h>
  20#include <linux/kernel.h>
  21#include <linux/interrupt.h>
  22#include <linux/platform_device.h>
  23#include <linux/dma-mapping.h>
  24#include <linux/io.h>
  25#include <linux/of_platform.h>
  26
  27/* USBSS register offsets */
  28#define USBSS_REVISION          0x0000
  29#define USBSS_SYSCONFIG         0x0010
  30#define USBSS_IRQ_EOI           0x0018
  31#define USBSS_IRQSTATUS_RAW_0   0x0020
  32#define USBSS_IRQSTATUS_0       0x0024
  33#define USBSS_IRQENABLE_SET_0   0x0028
  34#define USBSS_IRQENABLE_CLR_0   0x002c
  35
  36/* IRQ register bits */
  37#define USBSS_IRQ_EOI_LINE(n)   BIT(n)
  38#define USBSS_IRQ_EVENT_ST      BIT(0)
  39#define USBSS_IRQ_COREIRQ_EN    BIT(0)
  40#define USBSS_IRQ_COREIRQ_CLR   BIT(0)
  41
  42struct dwc3_keystone {
  43        struct device                   *dev;
  44        struct clk                      *clk;
  45        void __iomem                    *usbss;
  46};
  47
  48static inline u32 kdwc3_readl(void __iomem *base, u32 offset)
  49{
  50        return readl(base + offset);
  51}
  52
  53static inline void kdwc3_writel(void __iomem *base, u32 offset, u32 value)
  54{
  55        writel(value, base + offset);
  56}
  57
  58static void kdwc3_enable_irqs(struct dwc3_keystone *kdwc)
  59{
  60        u32 val;
  61
  62        val = kdwc3_readl(kdwc->usbss, USBSS_IRQENABLE_SET_0);
  63        val |= USBSS_IRQ_COREIRQ_EN;
  64        kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, val);
  65}
  66
  67static void kdwc3_disable_irqs(struct dwc3_keystone *kdwc)
  68{
  69        u32 val;
  70
  71        val = kdwc3_readl(kdwc->usbss, USBSS_IRQENABLE_SET_0);
  72        val &= ~USBSS_IRQ_COREIRQ_EN;
  73        kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, val);
  74}
  75
  76static irqreturn_t dwc3_keystone_interrupt(int irq, void *_kdwc)
  77{
  78        struct dwc3_keystone    *kdwc = _kdwc;
  79
  80        kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_CLR_0, USBSS_IRQ_COREIRQ_CLR);
  81        kdwc3_writel(kdwc->usbss, USBSS_IRQSTATUS_0, USBSS_IRQ_EVENT_ST);
  82        kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, USBSS_IRQ_COREIRQ_EN);
  83        kdwc3_writel(kdwc->usbss, USBSS_IRQ_EOI, USBSS_IRQ_EOI_LINE(0));
  84
  85        return IRQ_HANDLED;
  86}
  87
  88static int kdwc3_probe(struct platform_device *pdev)
  89{
  90        struct device           *dev = &pdev->dev;
  91        struct device_node      *node = pdev->dev.of_node;
  92        struct dwc3_keystone    *kdwc;
  93        struct resource         *res;
  94        int                     error, irq;
  95
  96        kdwc = devm_kzalloc(dev, sizeof(*kdwc), GFP_KERNEL);
  97        if (!kdwc)
  98                return -ENOMEM;
  99
 100        platform_set_drvdata(pdev, kdwc);
 101
 102        kdwc->dev = dev;
 103
 104        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 105        kdwc->usbss = devm_ioremap_resource(dev, res);
 106        if (IS_ERR(kdwc->usbss))
 107                return PTR_ERR(kdwc->usbss);
 108
 109        kdwc->clk = devm_clk_get(kdwc->dev, "usb");
 110
 111        error = clk_prepare_enable(kdwc->clk);
 112        if (error < 0) {
 113                dev_err(kdwc->dev, "unable to enable usb clock, error %d\n",
 114                        error);
 115                return error;
 116        }
 117
 118        irq = platform_get_irq(pdev, 0);
 119        if (irq < 0) {
 120                dev_err(&pdev->dev, "missing irq\n");
 121                error = irq;
 122                goto err_irq;
 123        }
 124
 125        error = devm_request_irq(dev, irq, dwc3_keystone_interrupt, IRQF_SHARED,
 126                        dev_name(dev), kdwc);
 127        if (error) {
 128                dev_err(dev, "failed to request IRQ #%d --> %d\n",
 129                                irq, error);
 130                goto err_irq;
 131        }
 132
 133        kdwc3_enable_irqs(kdwc);
 134
 135        error = of_platform_populate(node, NULL, NULL, dev);
 136        if (error) {
 137                dev_err(&pdev->dev, "failed to create dwc3 core\n");
 138                goto err_core;
 139        }
 140
 141        return 0;
 142
 143err_core:
 144        kdwc3_disable_irqs(kdwc);
 145err_irq:
 146        clk_disable_unprepare(kdwc->clk);
 147
 148        return error;
 149}
 150
 151static int kdwc3_remove_core(struct device *dev, void *c)
 152{
 153        struct platform_device *pdev = to_platform_device(dev);
 154
 155        platform_device_unregister(pdev);
 156
 157        return 0;
 158}
 159
 160static int kdwc3_remove(struct platform_device *pdev)
 161{
 162        struct dwc3_keystone *kdwc = platform_get_drvdata(pdev);
 163
 164        kdwc3_disable_irqs(kdwc);
 165        device_for_each_child(&pdev->dev, NULL, kdwc3_remove_core);
 166        clk_disable_unprepare(kdwc->clk);
 167        platform_set_drvdata(pdev, NULL);
 168
 169        return 0;
 170}
 171
 172static const struct of_device_id kdwc3_of_match[] = {
 173        { .compatible = "ti,keystone-dwc3", },
 174        {},
 175};
 176MODULE_DEVICE_TABLE(of, kdwc3_of_match);
 177
 178static struct platform_driver kdwc3_driver = {
 179        .probe          = kdwc3_probe,
 180        .remove         = kdwc3_remove,
 181        .driver         = {
 182                .name   = "keystone-dwc3",
 183                .of_match_table = kdwc3_of_match,
 184        },
 185};
 186
 187module_platform_driver(kdwc3_driver);
 188
 189MODULE_ALIAS("platform:keystone-dwc3");
 190MODULE_AUTHOR("WingMan Kwok <w-kwok2@ti.com>");
 191MODULE_LICENSE("GPL v2");
 192MODULE_DESCRIPTION("DesignWare USB3 KEYSTONE Glue Layer");
 193
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