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 struct dwc3_keystone {
  43         struct device                   *dev;
  44         struct clk                      *clk;
  45         void __iomem                    *usbss;
  46 };
  47
  48 static inline u32 kdwc3_readl(void __iomem *base, u32 offset)
  49 {
  50         return readl(base + offset);
  51 }
  52
  53 static inline void kdwc3_writel(void __iomem *base, u32 offset, u32 value)
  54 {
  55         writel(value, base + offset);
  56 }
  57
  58 static 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
  67 static 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
  76 static 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
  88 static 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         if (IS_ERR(kdwc->clk)) {
 111                 dev_err(kdwc->dev, "unable to get usb clock\n");
 112                 return PTR_ERR(kdwc->clk);
 113         }
 114
 115         error = clk_prepare_enable(kdwc->clk);
 116         if (error < 0) {
 117                 dev_err(kdwc->dev, "unable to enable usb clock, error %d\n",
 118                         error);
 119                 return error;
 120         }
 121
 122         irq = platform_get_irq(pdev, 0);
 123         if (irq < 0) {
 124                 dev_err(&pdev->dev, "missing irq\n");
 125                 error = irq;
 126                 goto err_irq;
 127         }
 128
 129         error = devm_request_irq(dev, irq, dwc3_keystone_interrupt, IRQF_SHARED,
 130                         dev_name(dev), kdwc);
 131         if (error) {
 132                 dev_err(dev, "failed to request IRQ #%d --> %d\n",
 133                                 irq, error);
 134                 goto err_irq;
 135         }
 136
 137         kdwc3_enable_irqs(kdwc);
 138
 139         error = of_platform_populate(node, NULL, NULL, dev);
 140         if (error) {
 141                 dev_err(&pdev->dev, "failed to create dwc3 core\n");
 142                 goto err_core;
 143         }
 144
 145         return 0;
 146
 147 err_core:
 148         kdwc3_disable_irqs(kdwc);
 149 err_irq:
 150         clk_disable_unprepare(kdwc->clk);
 151
 152         return error;
 153 }
 154
 155 static int kdwc3_remove_core(struct device *dev, void *c)
 156 {
 157         struct platform_device *pdev = to_platform_device(dev);
 158
 159         platform_device_unregister(pdev);
 160
 161         return 0;
 162 }
 163
 164 static int kdwc3_remove(struct platform_device *pdev)
 165 {
 166         struct dwc3_keystone *kdwc = platform_get_drvdata(pdev);
 167
 168         kdwc3_disable_irqs(kdwc);
 169         device_for_each_child(&pdev->dev, NULL, kdwc3_remove_core);
 170         clk_disable_unprepare(kdwc->clk);
 171         platform_set_drvdata(pdev, NULL);
 172
 173         return 0;
 174 }
 175
 176 static const struct of_device_id kdwc3_of_match[] = {
 177         { .compatible = "ti,keystone-dwc3", },
 178         {},
 179 };
 180 MODULE_DEVICE_TABLE(of, kdwc3_of_match);
 181
 182 static struct platform_driver kdwc3_driver = {
 183         .probe          = kdwc3_probe,
 184         .remove         = kdwc3_remove,
 185         .driver         = {
 186                 .name   = "keystone-dwc3",
 187                 .of_match_table = kdwc3_of_match,
 188         },
 189 };
 190
 191 module_platform_driver(kdwc3_driver);
 192
 193 MODULE_ALIAS("platform:keystone-dwc3");
 194 MODULE_AUTHOR("WingMan Kwok <w-kwok2@ti.com>");
 195 MODULE_LICENSE("GPL v2");
 196 MODULE_DESCRIPTION("DesignWare USB3 KEYSTONE Glue Layer");