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 31 /* interface and function clocks */ 32 #define hcd_to_atmel_ehci_priv(h) \ 33 ((struct atmel_ehci_priv *)hcd_to_ehci(h)->priv) 34 35 struct atmel_ehci_priv { 36 struct clk *iclk; 37 struct clk *uclk; 38 bool clocked; 39 }; 40 41 static struct hc_driver __read_mostly ehci_atmel_hc_driver; 42 43 static const struct ehci_driver_overrides ehci_atmel_drv_overrides __initconst = { 44 .extra_priv_size = sizeof(struct atmel_ehci_priv), 45 }; 46 47 /*-------------------------------------------------------------------------*/ 48 49 static void atmel_start_clock(struct atmel_ehci_priv *atmel_ehci) 50 { 51 if (atmel_ehci->clocked) 52 return; 53 54 clk_prepare_enable(atmel_ehci->uclk); 55 clk_prepare_enable(atmel_ehci->iclk); 56 atmel_ehci->clocked = true; 57 } 58 59 static void atmel_stop_clock(struct atmel_ehci_priv *atmel_ehci) 60 { 61 if (!atmel_ehci->clocked) 62 return; 63 64 clk_disable_unprepare(atmel_ehci->iclk); 65 clk_disable_unprepare(atmel_ehci->uclk); 66 atmel_ehci->clocked = false; 67 } 68 69 static void atmel_start_ehci(struct platform_device *pdev) 70 { 71 struct usb_hcd *hcd = platform_get_drvdata(pdev); 72 struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd); 73 74 dev_dbg(&pdev->dev, "start\n"); 75 atmel_start_clock(atmel_ehci); 76 } 77 78 static void atmel_stop_ehci(struct platform_device *pdev) 79 { 80 struct usb_hcd *hcd = platform_get_drvdata(pdev); 81 struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd); 82 83 dev_dbg(&pdev->dev, "stop\n"); 84 atmel_stop_clock(atmel_ehci); 85 } 86 87 /*-------------------------------------------------------------------------*/ 88 89 static int ehci_atmel_drv_probe(struct platform_device *pdev) 90 { 91 struct usb_hcd *hcd; 92 const struct hc_driver *driver = &ehci_atmel_hc_driver; 93 struct resource *res; 94 struct ehci_hcd *ehci; 95 struct atmel_ehci_priv *atmel_ehci; 96 int irq; 97 int retval; 98 99 if (usb_disabled()) 100 return -ENODEV; 101 102 pr_debug("Initializing Atmel-SoC USB Host Controller\n"); 103 104 irq = platform_get_irq(pdev, 0); 105 if (irq <= 0) { 106 dev_err(&pdev->dev, 107 "Found HC with no IRQ. Check %s setup!\n", 108 dev_name(&pdev->dev)); 109 retval = -ENODEV; 110 goto fail_create_hcd; 111 } 112 113 /* Right now device-tree probed devices don't get dma_mask set. 114 * Since shared usb code relies on it, set it here for now. 115 * Once we have dma capability bindings this can go away. 116 */ 117 retval = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); 118 if (retval) 119 goto fail_create_hcd; 120 121 hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev)); 122 if (!hcd) { 123 retval = -ENOMEM; 124 goto fail_create_hcd; 125 } 126 atmel_ehci = hcd_to_atmel_ehci_priv(hcd); 127 128 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 129 hcd->regs = devm_ioremap_resource(&pdev->dev, res); 130 if (IS_ERR(hcd->regs)) { 131 retval = PTR_ERR(hcd->regs); 132 goto fail_request_resource; 133 } 134 135 hcd->rsrc_start = res->start; 136 hcd->rsrc_len = resource_size(res); 137 138 atmel_ehci->iclk = devm_clk_get(&pdev->dev, "ehci_clk"); 139 if (IS_ERR(atmel_ehci->iclk)) { 140 dev_err(&pdev->dev, "Error getting interface clock\n"); 141 retval = -ENOENT; 142 goto fail_request_resource; 143 } 144 145 atmel_ehci->uclk = devm_clk_get(&pdev->dev, "usb_clk"); 146 if (IS_ERR(atmel_ehci->uclk)) { 147 dev_err(&pdev->dev, "failed to get uclk\n"); 148 retval = PTR_ERR(atmel_ehci->uclk); 149 goto fail_request_resource; 150 } 151 152 ehci = hcd_to_ehci(hcd); 153 /* registers start at offset 0x0 */ 154 ehci->caps = hcd->regs; 155 156 atmel_start_ehci(pdev); 157 158 retval = usb_add_hcd(hcd, irq, IRQF_SHARED); 159 if (retval) 160 goto fail_add_hcd; 161 device_wakeup_enable(hcd->self.controller); 162 163 return retval; 164 165 fail_add_hcd: 166 atmel_stop_ehci(pdev); 167 fail_request_resource: 168 usb_put_hcd(hcd); 169 fail_create_hcd: 170 dev_err(&pdev->dev, "init %s fail, %d\n", 171 dev_name(&pdev->dev), retval); 172 173 return retval; 174 } 175 176 static int ehci_atmel_drv_remove(struct platform_device *pdev) 177 { 178 struct usb_hcd *hcd = platform_get_drvdata(pdev); 179 180 usb_remove_hcd(hcd); 181 usb_put_hcd(hcd); 182 183 atmel_stop_ehci(pdev); 184 185 return 0; 186 } 187 188 static int __maybe_unused ehci_atmel_drv_suspend(struct device *dev) 189 { 190 struct usb_hcd *hcd = dev_get_drvdata(dev); 191 struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd); 192 int ret; 193 194 ret = ehci_suspend(hcd, false); 195 if (ret) 196 return ret; 197 198 atmel_stop_clock(atmel_ehci); 199 return 0; 200 } 201 202 static int __maybe_unused ehci_atmel_drv_resume(struct device *dev) 203 { 204 struct usb_hcd *hcd = dev_get_drvdata(dev); 205 struct atmel_ehci_priv *atmel_ehci = hcd_to_atmel_ehci_priv(hcd); 206 207 atmel_start_clock(atmel_ehci); 208 return ehci_resume(hcd, false); 209 } 210 211 #ifdef CONFIG_OF 212 static const struct of_device_id atmel_ehci_dt_ids[] = { 213 { .compatible = "atmel,at91sam9g45-ehci" }, 214 { /* sentinel */ } 215 }; 216 217 MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids); 218 #endif 219 220 static SIMPLE_DEV_PM_OPS(ehci_atmel_pm_ops, ehci_atmel_drv_suspend, 221 ehci_atmel_drv_resume); 222 223 static struct platform_driver ehci_atmel_driver = { 224 .probe = ehci_atmel_drv_probe, 225 .remove = ehci_atmel_drv_remove, 226 .shutdown = usb_hcd_platform_shutdown, 227 .driver = { 228 .name = "atmel-ehci", 229 .pm = &ehci_atmel_pm_ops, 230 .of_match_table = of_match_ptr(atmel_ehci_dt_ids), 231 }, 232 }; 233 234 static int __init ehci_atmel_init(void) 235 { 236 if (usb_disabled()) 237 return -ENODEV; 238 239 pr_info("%s: " DRIVER_DESC "\n", hcd_name); 240 ehci_init_driver(&ehci_atmel_hc_driver, &ehci_atmel_drv_overrides); 241 return platform_driver_register(&ehci_atmel_driver); 242 } 243 module_init(ehci_atmel_init); 244 245 static void __exit ehci_atmel_cleanup(void) 246 { 247 platform_driver_unregister(&ehci_atmel_driver); 248 } 249 module_exit(ehci_atmel_cleanup); 250 251 MODULE_DESCRIPTION(DRIVER_DESC); 252 MODULE_ALIAS("platform:atmel-ehci"); 253 MODULE_AUTHOR("Nicolas Ferre"); 254 MODULE_LICENSE("GPL"); 255