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, *uclk; 34 static int clocked; 35 36 /*-------------------------------------------------------------------------*/ 37 38 static void atmel_start_clock(void) 39 { 40 if (IS_ENABLED(CONFIG_COMMON_CLK)) { 41 clk_set_rate(uclk, 48000000); 42 clk_prepare_enable(uclk); 43 } 44 clk_prepare_enable(iclk); 45 clk_prepare_enable(fclk); 46 clocked = 1; 47 } 48 49 static void atmel_stop_clock(void) 50 { 51 clk_disable_unprepare(fclk); 52 clk_disable_unprepare(iclk); 53 if (IS_ENABLED(CONFIG_COMMON_CLK)) 54 clk_disable_unprepare(uclk); 55 clocked = 0; 56 } 57 58 static void atmel_start_ehci(struct platform_device *pdev) 59 { 60 dev_dbg(&pdev->dev, "start\n"); 61 atmel_start_clock(); 62 } 63 64 static void atmel_stop_ehci(struct platform_device *pdev) 65 { 66 dev_dbg(&pdev->dev, "stop\n"); 67 atmel_stop_clock(); 68 } 69 70 /*-------------------------------------------------------------------------*/ 71 72 static int ehci_atmel_drv_probe(struct platform_device *pdev) 73 { 74 struct usb_hcd *hcd; 75 const struct hc_driver *driver = &ehci_atmel_hc_driver; 76 struct resource *res; 77 struct ehci_hcd *ehci; 78 int irq; 79 int retval; 80 81 if (usb_disabled()) 82 return -ENODEV; 83 84 pr_debug("Initializing Atmel-SoC USB Host Controller\n"); 85 86 irq = platform_get_irq(pdev, 0); 87 if (irq <= 0) { 88 dev_err(&pdev->dev, 89 "Found HC with no IRQ. Check %s setup!\n", 90 dev_name(&pdev->dev)); 91 retval = -ENODEV; 92 goto fail_create_hcd; 93 } 94 95 /* Right now device-tree probed devices don't get dma_mask set. 96 * Since shared usb code relies on it, set it here for now. 97 * Once we have dma capability bindings this can go away. 98 */ 99 retval = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32)); 100 if (retval) 101 goto fail_create_hcd; 102 103 hcd = usb_create_hcd(driver, &pdev->dev, dev_name(&pdev->dev)); 104 if (!hcd) { 105 retval = -ENOMEM; 106 goto fail_create_hcd; 107 } 108 109 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 110 hcd->regs = devm_ioremap_resource(&pdev->dev, res); 111 if (IS_ERR(hcd->regs)) { 112 retval = PTR_ERR(hcd->regs); 113 goto fail_request_resource; 114 } 115 116 hcd->rsrc_start = res->start; 117 hcd->rsrc_len = resource_size(res); 118 119 iclk = devm_clk_get(&pdev->dev, "ehci_clk"); 120 if (IS_ERR(iclk)) { 121 dev_err(&pdev->dev, "Error getting interface clock\n"); 122 retval = -ENOENT; 123 goto fail_request_resource; 124 } 125 fclk = devm_clk_get(&pdev->dev, "uhpck"); 126 if (IS_ERR(fclk)) { 127 dev_err(&pdev->dev, "Error getting function clock\n"); 128 retval = -ENOENT; 129 goto fail_request_resource; 130 } 131 if (IS_ENABLED(CONFIG_COMMON_CLK)) { 132 uclk = devm_clk_get(&pdev->dev, "usb_clk"); 133 if (IS_ERR(uclk)) { 134 dev_err(&pdev->dev, "failed to get uclk\n"); 135 retval = PTR_ERR(uclk); 136 goto fail_request_resource; 137 } 138 } 139 140 ehci = hcd_to_ehci(hcd); 141 /* registers start at offset 0x0 */ 142 ehci->caps = hcd->regs; 143 144 atmel_start_ehci(pdev); 145 146 retval = usb_add_hcd(hcd, irq, IRQF_SHARED); 147 if (retval) 148 goto fail_add_hcd; 149 device_wakeup_enable(hcd->self.controller); 150 151 return retval; 152 153 fail_add_hcd: 154 atmel_stop_ehci(pdev); 155 fail_request_resource: 156 usb_put_hcd(hcd); 157 fail_create_hcd: 158 dev_err(&pdev->dev, "init %s fail, %d\n", 159 dev_name(&pdev->dev), retval); 160 161 return retval; 162 } 163 164 static int ehci_atmel_drv_remove(struct platform_device *pdev) 165 { 166 struct usb_hcd *hcd = platform_get_drvdata(pdev); 167 168 usb_remove_hcd(hcd); 169 usb_put_hcd(hcd); 170 171 atmel_stop_ehci(pdev); 172 fclk = iclk = NULL; 173 174 return 0; 175 } 176 177 #ifdef CONFIG_OF 178 static const struct of_device_id atmel_ehci_dt_ids[] = { 179 { .compatible = "atmel,at91sam9g45-ehci" }, 180 { /* sentinel */ } 181 }; 182 183 MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids); 184 #endif 185 186 static struct platform_driver ehci_atmel_driver = { 187 .probe = ehci_atmel_drv_probe, 188 .remove = ehci_atmel_drv_remove, 189 .shutdown = usb_hcd_platform_shutdown, 190 .driver = { 191 .name = "atmel-ehci", 192 .of_match_table = of_match_ptr(atmel_ehci_dt_ids), 193 }, 194 }; 195 196 static int __init ehci_atmel_init(void) 197 { 198 if (usb_disabled()) 199 return -ENODEV; 200 201 pr_info("%s: " DRIVER_DESC "\n", hcd_name); 202 ehci_init_driver(&ehci_atmel_hc_driver, NULL); 203 return platform_driver_register(&ehci_atmel_driver); 204 } 205 module_init(ehci_atmel_init); 206 207 static void __exit ehci_atmel_cleanup(void) 208 { 209 platform_driver_unregister(&ehci_atmel_driver); 210 } 211 module_exit(ehci_atmel_cleanup); 212 213 MODULE_DESCRIPTION(DRIVER_DESC); 214 MODULE_ALIAS("platform:atmel-ehci"); 215 MODULE_AUTHOR("Nicolas Ferre"); 216 MODULE_LICENSE("GPL"); 217