1 /* 2 * Driver for EHCI UHP on Atmel chips 3 * 4 * Copyright (C) 2009 Atmel Corporation, 5 * Nicolas Ferre <nicolas.ferre@atmel.com> 6 * 7 * Based on various ehci-*.c drivers 8 * 9 * This file is subject to the terms and conditions of the GNU General Public 10 * License. See the file COPYING in the main directory of this archive for 11 * more details. 12 */ 13 14 #include <linux/clk.h> 15 #include <linux/dma-mapping.h> 16 #include <linux/io.h> 17 #include <linux/kernel.h> 18 #include <linux/module.h> 19 #include <linux/of.h> 20 #include <linux/of_platform.h> 21 #include <linux/platform_device.h> 22 #include <linux/usb.h> 23 #include <linux/usb/hcd.h> 24 25 #include "ehci.h" 26 27 #define DRIVER_DESC "EHCI Atmel driver" 28 29 static const char hcd_name[] = "ehci-atmel"; 30 static struct hc_driver __read_mostly ehci_atmel_hc_driver; 31 32 /* interface and function clocks */ 33 static struct clk *iclk, *fclk; 34 static int clocked; 35 36 /*-------------------------------------------------------------------------*/ 37 38 static void atmel_start_clock(void) 39 { 40 clk_prepare_enable(iclk); 41 clk_prepare_enable(fclk); 42 clocked = 1; 43 } 44 45 static void atmel_stop_clock(void) 46 { 47 clk_disable_unprepare(fclk); 48 clk_disable_unprepare(iclk); 49 clocked = 0; 50 } 51 52 static void atmel_start_ehci(struct platform_device *pdev) 53 { 54 dev_dbg(&pdev->dev, "start\n"); 55 atmel_start_clock(); 56 } 57 58 static void atmel_stop_ehci(struct platform_device *pdev) 59 { 60 dev_dbg(&pdev->dev, "stop\n"); 61 atmel_stop_clock(); 62 } 63 64 /*-------------------------------------------------------------------------*/ 65 66 static int ehci_atmel_drv_probe(struct platform_device *pdev) 67 { 68 struct usb_hcd *hcd; 69 const struct hc_driver *driver = &ehci_atmel_hc_driver; 70 struct resource *res; 71 struct ehci_hcd *ehci; 72 int irq; 73 int retval; 74 75 if (usb_disabled()) 76 return -ENODEV; 77 78 pr_debug("Initializing Atmel-SoC USB Host Controller\n"); 79 80 irq = platform_get_irq(pdev, 0); 81 if (irq <= 0) { 82 dev_err(&pdev->dev, 83 "Found HC with no IRQ. Check %s setup!\n", 84 dev_name(&pdev->dev)); 85 retval = -ENODEV; 86 goto fail_create_hcd; 87 } 88 89 /* Right now device-tree probed devices don't get dma_mask set. 90 * Since shared usb code relies on it, set it here for now. 91 * Once we have dma capability bindings this can go away. 92 */ 93 if (!pdev->dev.dma_mask) 94 pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask; 95 if (!pdev->dev.coherent_dma_mask) 96 pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32); 97 98 hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev)); 99 if (!hcd) { 100 retval = -ENOMEM; 101 goto fail_create_hcd; 102 } 103 104 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 105 if (!res) { 106 dev_err(&pdev->dev, 107 "Found HC with no register addr. Check %s setup!\n", 108 dev_name(&pdev->dev)); 109 retval = -ENODEV; 110 goto fail_request_resource; 111 } 112 hcd->rsrc_start = res->start; 113 hcd->rsrc_len = resource_size(res); 114 115 hcd->regs = devm_ioremap_resource(&pdev->dev, res); 116 if (IS_ERR(hcd->regs)) { 117 retval = PTR_ERR(hcd->regs); 118 goto fail_request_resource; 119 } 120 121 iclk = devm_clk_get(&pdev->dev, "ehci_clk"); 122 if (IS_ERR(iclk)) { 123 dev_err(&pdev->dev, "Error getting interface clock\n"); 124 retval = -ENOENT; 125 goto fail_request_resource; 126 } 127 fclk = devm_clk_get(&pdev->dev, "uhpck"); 128 if (IS_ERR(fclk)) { 129 dev_err(&pdev->dev, "Error getting function clock\n"); 130 retval = -ENOENT; 131 goto fail_request_resource; 132 } 133 134 ehci = hcd_to_ehci(hcd); 135 /* registers start at offset 0x0 */ 136 ehci->caps = hcd->regs; 137 138 atmel_start_ehci(pdev); 139 140 retval = usb_add_hcd(hcd, irq, IRQF_SHARED); 141 if (retval) 142 goto fail_add_hcd; 143 144 return retval; 145 146 fail_add_hcd: 147 atmel_stop_ehci(pdev); 148 fail_request_resource: 149 usb_put_hcd(hcd); 150 fail_create_hcd: 151 dev_err(&pdev->dev, "init %s fail, %d\n", 152 dev_name(&pdev->dev), retval); 153 154 return retval; 155 } 156 157 static int ehci_atmel_drv_remove(struct platform_device *pdev) 158 { 159 struct usb_hcd *hcd = platform_get_drvdata(pdev); 160 161 usb_remove_hcd(hcd); 162 usb_put_hcd(hcd); 163 164 atmel_stop_ehci(pdev); 165 fclk = iclk = NULL; 166 167 return 0; 168 } 169 170 #ifdef CONFIG_OF 171 static const struct of_device_id atmel_ehci_dt_ids[] = { 172 { .compatible = "atmel,at91sam9g45-ehci" }, 173 { /* sentinel */ } 174 }; 175 176 MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids); 177 #endif 178 179 static struct platform_driver ehci_atmel_driver = { 180 .probe = ehci_atmel_drv_probe, 181 .remove = ehci_atmel_drv_remove, 182 .shutdown = usb_hcd_platform_shutdown, 183 .driver = { 184 .name = "atmel-ehci", 185 .of_match_table = of_match_ptr(atmel_ehci_dt_ids), 186 }, 187 }; 188 189 static int __init ehci_atmel_init(void) 190 { 191 if (usb_disabled()) 192 return -ENODEV; 193 194 pr_info("%s: " DRIVER_DESC "\n", hcd_name); 195 ehci_init_driver(&ehci_atmel_hc_driver, NULL); 196 return platform_driver_register(&ehci_atmel_driver); 197 } 198 module_init(ehci_atmel_init); 199 200 static void __exit ehci_atmel_cleanup(void) 201 { 202 platform_driver_unregister(&ehci_atmel_driver); 203 } 204 module_exit(ehci_atmel_cleanup); 205 206 MODULE_DESCRIPTION(DRIVER_DESC); 207 MODULE_ALIAS("platform:atmel-ehci"); 208 MODULE_AUTHOR("Nicolas Ferre"); 209 MODULE_LICENSE("GPL"); 210