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Linux/drivers/usb/host/ehci-atmel.c

  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 

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