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"); 197