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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         if (!res) {
111                 dev_err(&pdev->dev,
112                         "Found HC with no register addr. Check %s setup!\n",
113                         dev_name(&pdev->dev));
114                 retval = -ENODEV;
115                 goto fail_request_resource;
116         }
117         hcd->rsrc_start = res->start;
118         hcd->rsrc_len = resource_size(res);
119 
120         hcd->regs = devm_ioremap_resource(&pdev->dev, res);
121         if (IS_ERR(hcd->regs)) {
122                 retval = PTR_ERR(hcd->regs);
123                 goto fail_request_resource;
124         }
125 
126         iclk = devm_clk_get(&pdev->dev, "ehci_clk");
127         if (IS_ERR(iclk)) {
128                 dev_err(&pdev->dev, "Error getting interface clock\n");
129                 retval = -ENOENT;
130                 goto fail_request_resource;
131         }
132         fclk = devm_clk_get(&pdev->dev, "uhpck");
133         if (IS_ERR(fclk)) {
134                 dev_err(&pdev->dev, "Error getting function clock\n");
135                 retval = -ENOENT;
136                 goto fail_request_resource;
137         }
138         if (IS_ENABLED(CONFIG_COMMON_CLK)) {
139                 uclk = devm_clk_get(&pdev->dev, "usb_clk");
140                 if (IS_ERR(uclk)) {
141                         dev_err(&pdev->dev, "failed to get uclk\n");
142                         retval = PTR_ERR(uclk);
143                         goto fail_request_resource;
144                 }
145         }
146 
147         ehci = hcd_to_ehci(hcd);
148         /* registers start at offset 0x0 */
149         ehci->caps = hcd->regs;
150 
151         atmel_start_ehci(pdev);
152 
153         retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
154         if (retval)
155                 goto fail_add_hcd;
156         device_wakeup_enable(hcd->self.controller);
157 
158         return retval;
159 
160 fail_add_hcd:
161         atmel_stop_ehci(pdev);
162 fail_request_resource:
163         usb_put_hcd(hcd);
164 fail_create_hcd:
165         dev_err(&pdev->dev, "init %s fail, %d\n",
166                 dev_name(&pdev->dev), retval);
167 
168         return retval;
169 }
170 
171 static int ehci_atmel_drv_remove(struct platform_device *pdev)
172 {
173         struct usb_hcd *hcd = platform_get_drvdata(pdev);
174 
175         usb_remove_hcd(hcd);
176         usb_put_hcd(hcd);
177 
178         atmel_stop_ehci(pdev);
179         fclk = iclk = NULL;
180 
181         return 0;
182 }
183 
184 #ifdef CONFIG_OF
185 static const struct of_device_id atmel_ehci_dt_ids[] = {
186         { .compatible = "atmel,at91sam9g45-ehci" },
187         { /* sentinel */ }
188 };
189 
190 MODULE_DEVICE_TABLE(of, atmel_ehci_dt_ids);
191 #endif
192 
193 static struct platform_driver ehci_atmel_driver = {
194         .probe          = ehci_atmel_drv_probe,
195         .remove         = ehci_atmel_drv_remove,
196         .shutdown       = usb_hcd_platform_shutdown,
197         .driver         = {
198                 .name   = "atmel-ehci",
199                 .of_match_table = of_match_ptr(atmel_ehci_dt_ids),
200         },
201 };
202 
203 static int __init ehci_atmel_init(void)
204 {
205         if (usb_disabled())
206                 return -ENODEV;
207 
208         pr_info("%s: " DRIVER_DESC "\n", hcd_name);
209         ehci_init_driver(&ehci_atmel_hc_driver, NULL);
210         return platform_driver_register(&ehci_atmel_driver);
211 }
212 module_init(ehci_atmel_init);
213 
214 static void __exit ehci_atmel_cleanup(void)
215 {
216         platform_driver_unregister(&ehci_atmel_driver);
217 }
218 module_exit(ehci_atmel_cleanup);
219 
220 MODULE_DESCRIPTION(DRIVER_DESC);
221 MODULE_ALIAS("platform:atmel-ehci");
222 MODULE_AUTHOR("Nicolas Ferre");
223 MODULE_LICENSE("GPL");
224 

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