drivers/usb/dwc3/dwc3-keystone.c

   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
  42 static u64 kdwc3_dma_mask;
  43
  44 struct dwc3_keystone {
  45         struct device                   *dev;
  46         struct clk                      *clk;
  47         void __iomem                    *usbss;
  48 };
  49
  50 static inline u32 kdwc3_readl(void __iomem *base, u32 offset)
  51 {
  52         return readl(base + offset);
  53 }
  54
  55 static inline void kdwc3_writel(void __iomem *base, u32 offset, u32 value)
  56 {
  57         writel(value, base + offset);
  58 }
  59
  60 static 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
  69 static 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
  78 static 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
  90 static 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_err(kdwc->dev, "unable to enable usb clock, error %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
 148 err_core:
 149         kdwc3_disable_irqs(kdwc);
 150 err_irq:
 151         clk_disable_unprepare(kdwc->clk);
 152
 153         return error;
 154 }
 155
 156 static 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
 165 static 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
 177 static const struct of_device_id kdwc3_of_match[] = {
 178         { .compatible = "ti,keystone-dwc3", },
 179         {},
 180 };
 181 MODULE_DEVICE_TABLE(of, kdwc3_of_match);
 182
 183 static 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
 192 module_platform_driver(kdwc3_driver);
 193
 194 MODULE_ALIAS("platform:keystone-dwc3");
 195 MODULE_AUTHOR("WingMan Kwok <w-kwok2@ti.com>");
 196 MODULE_LICENSE("GPL v2");
 197 MODULE_DESCRIPTION("DesignWare USB3 KEYSTONE Glue Layer");