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 if (!res) { 108 dev_err(dev, "missing usbss resource\n"); 109 return -EINVAL; 110 } 111 112 kdwc->usbss = devm_ioremap_resource(dev, res); 113 if (IS_ERR(kdwc->usbss)) 114 return PTR_ERR(kdwc->usbss); 115 116 kdwc3_dma_mask = dma_get_mask(dev); 117 dev->dma_mask = &kdwc3_dma_mask; 118 119 kdwc->clk = devm_clk_get(kdwc->dev, "usb"); 120 121 error = clk_prepare_enable(kdwc->clk); 122 if (error < 0) { 123 dev_dbg(kdwc->dev, "unable to enable usb clock, err %d\n", 124 error); 125 return error; 126 } 127 128 irq = platform_get_irq(pdev, 0); 129 if (irq < 0) { 130 dev_err(&pdev->dev, "missing irq\n"); 131 goto err_irq; 132 } 133 134 error = devm_request_irq(dev, irq, dwc3_keystone_interrupt, IRQF_SHARED, 135 dev_name(dev), kdwc); 136 if (error) { 137 dev_err(dev, "failed to request IRQ #%d --> %d\n", 138 irq, error); 139 goto err_irq; 140 } 141 142 kdwc3_enable_irqs(kdwc); 143 144 error = of_platform_populate(node, NULL, NULL, dev); 145 if (error) { 146 dev_err(&pdev->dev, "failed to create dwc3 core\n"); 147 goto err_core; 148 } 149 150 return 0; 151 152 err_core: 153 kdwc3_disable_irqs(kdwc); 154 err_irq: 155 clk_disable_unprepare(kdwc->clk); 156 157 return error; 158 } 159 160 static int kdwc3_remove_core(struct device *dev, void *c) 161 { 162 struct platform_device *pdev = to_platform_device(dev); 163 164 platform_device_unregister(pdev); 165 166 return 0; 167 } 168 169 static int kdwc3_remove(struct platform_device *pdev) 170 { 171 struct dwc3_keystone *kdwc = platform_get_drvdata(pdev); 172 173 kdwc3_disable_irqs(kdwc); 174 device_for_each_child(&pdev->dev, NULL, kdwc3_remove_core); 175 clk_disable_unprepare(kdwc->clk); 176 platform_set_drvdata(pdev, NULL); 177 178 return 0; 179 } 180 181 static const struct of_device_id kdwc3_of_match[] = { 182 { .compatible = "ti,keystone-dwc3", }, 183 {}, 184 }; 185 MODULE_DEVICE_TABLE(of, kdwc3_of_match); 186 187 static struct platform_driver kdwc3_driver = { 188 .probe = kdwc3_probe, 189 .remove = kdwc3_remove, 190 .driver = { 191 .name = "keystone-dwc3", 192 .owner = THIS_MODULE, 193 .of_match_table = kdwc3_of_match, 194 }, 195 }; 196 197 module_platform_driver(kdwc3_driver); 198 199 MODULE_ALIAS("platform:keystone-dwc3"); 200 MODULE_AUTHOR("WingMan Kwok <w-kwok2@ti.com>"); 201 MODULE_LICENSE("GPL v2"); 202 MODULE_DESCRIPTION("DesignWare USB3 KEYSTONE Glue Layer"); 203