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
  42static u64 kdwc3_dma_mask;
  43
  44struct dwc3_keystone {
  45        struct device                   *dev;
  46        struct clk                      *clk;
  47        void __iomem                    *usbss;
  48};
  49
  50static inline u32 kdwc3_readl(void __iomem *base, u32 offset)
  51{
  52        return readl(base + offset);
  53}
  54
  55static inline void kdwc3_writel(void __iomem *base, u32 offset, u32 value)
  56{
  57        writel(value, base + offset);
  58}
  59
  60static void kdwc3_enable_irqs(struct dwc3_keystone *kdwc)
  61{
  62        u32 val;
  63
  64        val = kdwc3_readl(kdwc->usbss, USBSS_IRQENABLE_SET_0);
  65        val |= USBSS_IRQ_COREIRQ_EN;
  66        kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, val);
  67}
  68
  69static void kdwc3_disable_irqs(struct dwc3_keystone *kdwc)
  70{
  71        u32 val;
  72
  73        val = kdwc3_readl(kdwc->usbss, USBSS_IRQENABLE_SET_0);
  74        val &= ~USBSS_IRQ_COREIRQ_EN;
  75        kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, val);
  76}
  77
  78static irqreturn_t dwc3_keystone_interrupt(int irq, void *_kdwc)
  79{
  80        struct dwc3_keystone    *kdwc = _kdwc;
  81
  82        kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_CLR_0, USBSS_IRQ_COREIRQ_CLR);
  83        kdwc3_writel(kdwc->usbss, USBSS_IRQSTATUS_0, USBSS_IRQ_EVENT_ST);
  84        kdwc3_writel(kdwc->usbss, USBSS_IRQENABLE_SET_0, USBSS_IRQ_COREIRQ_EN);
  85        kdwc3_writel(kdwc->usbss, USBSS_IRQ_EOI, USBSS_IRQ_EOI_LINE(0));
  86
  87        return IRQ_HANDLED;
  88}
  89
  90static int kdwc3_probe(struct platform_device *pdev)
  91{
  92        struct device           *dev = &pdev->dev;
  93        struct device_node      *node = pdev->dev.of_node;
  94        struct dwc3_keystone    *kdwc;
  95        struct resource         *res;
  96        int                     error, irq;
  97
  98        kdwc = devm_kzalloc(dev, sizeof(*kdwc), GFP_KERNEL);
  99        if (!kdwc)
 100                return -ENOMEM;
 101
 102        platform_set_drvdata(pdev, kdwc);
 103
 104        kdwc->dev = dev;
 105
 106        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 107        kdwc->usbss = devm_ioremap_resource(dev, res);
 108        if (IS_ERR(kdwc->usbss))
 109                return PTR_ERR(kdwc->usbss);
 110
 111        kdwc3_dma_mask = dma_get_mask(dev);
 112        dev->dma_mask = &kdwc3_dma_mask;
 113
 114        kdwc->clk = devm_clk_get(kdwc->dev, "usb");
 115
 116        error = clk_prepare_enable(kdwc->clk);
 117        if (error < 0) {
 118                dev_dbg(kdwc->dev, "unable to enable usb clock, err %d\n",
 119                        error);
 120                return error;
 121        }
 122
 123        irq = platform_get_irq(pdev, 0);
 124        if (irq < 0) {
 125                dev_err(&pdev->dev, "missing irq\n");
 126                error = irq;
 127                goto err_irq;
 128        }
 129
 130        error = devm_request_irq(dev, irq, dwc3_keystone_interrupt, IRQF_SHARED,
 131                        dev_name(dev), kdwc);
 132        if (error) {
 133                dev_err(dev, "failed to request IRQ #%d --> %d\n",
 134                                irq, error);
 135                goto err_irq;
 136        }
 137
 138        kdwc3_enable_irqs(kdwc);
 139
 140        error = of_platform_populate(node, NULL, NULL, dev);
 141        if (error) {
 142                dev_err(&pdev->dev, "failed to create dwc3 core\n");
 143                goto err_core;
 144        }
 145
 146        return 0;
 147
 148err_core:
 149        kdwc3_disable_irqs(kdwc);
 150err_irq:
 151        clk_disable_unprepare(kdwc->clk);
 152
 153        return error;
 154}
 155
 156static int kdwc3_remove_core(struct device *dev, void *c)
 157{
 158        struct platform_device *pdev = to_platform_device(dev);
 159
 160        platform_device_unregister(pdev);
 161
 162        return 0;
 163}
 164
 165static int kdwc3_remove(struct platform_device *pdev)
 166{
 167        struct dwc3_keystone *kdwc = platform_get_drvdata(pdev);
 168
 169        kdwc3_disable_irqs(kdwc);
 170        device_for_each_child(&pdev->dev, NULL, kdwc3_remove_core);
 171        clk_disable_unprepare(kdwc->clk);
 172        platform_set_drvdata(pdev, NULL);
 173
 174        return 0;
 175}
 176
 177static const struct of_device_id kdwc3_of_match[] = {
 178        { .compatible = "ti,keystone-dwc3", },
 179        {},
 180};
 181MODULE_DEVICE_TABLE(of, kdwc3_of_match);
 182
 183static struct platform_driver kdwc3_driver = {
 184        .probe          = kdwc3_probe,
 185        .remove         = kdwc3_remove,
 186        .driver         = {
 187                .name   = "keystone-dwc3",
 188                .of_match_table = kdwc3_of_match,
 189        },
 190};
 191
 192module_platform_driver(kdwc3_driver);
 193
 194MODULE_ALIAS("platform:keystone-dwc3");
 195MODULE_AUTHOR("WingMan Kwok <w-kwok2@ti.com>");
 196MODULE_LICENSE("GPL v2");
 197MODULE_DESCRIPTION("DesignWare USB3 KEYSTONE Glue Layer");
 198
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