Linux kernel & device driver programming

Cross-Referenced Linux and Device Driver Code

[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ]
Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  * OHCI HCD (Host Controller Driver) for USB.
  3  *
  4  *  Copyright (C) 2004 SAN People (Pty) Ltd.
  5  *  Copyright (C) 2005 Thibaut VARENE <varenet@parisc-linux.org>
  6  *
  7  * AT91 Bus Glue
  8  *
  9  * Based on fragments of 2.4 driver by Rick Bronson.
 10  * Based on ohci-omap.c
 11  *
 12  * This file is licenced under the GPL.
 13  */
 14 
 15 #include <linux/clk.h>
 16 #include <linux/platform_device.h>
 17 
 18 #include <mach/hardware.h>
 19 #include <asm/gpio.h>
 20 
 21 #include <mach/board.h>
 22 #include <mach/cpu.h>
 23 
 24 #ifndef CONFIG_ARCH_AT91
 25 #error "CONFIG_ARCH_AT91 must be defined."
 26 #endif
 27 
 28 /* interface and function clocks; sometimes also an AHB clock */
 29 static struct clk *iclk, *fclk, *hclk;
 30 static int clocked;
 31 
 32 extern int usb_disabled(void);
 33 
 34 /*-------------------------------------------------------------------------*/
 35 
 36 static void at91_start_clock(void)
 37 {
 38         if (cpu_is_at91sam9261())
 39                 clk_enable(hclk);
 40         clk_enable(iclk);
 41         clk_enable(fclk);
 42         clocked = 1;
 43 }
 44 
 45 static void at91_stop_clock(void)
 46 {
 47         clk_disable(fclk);
 48         clk_disable(iclk);
 49         if (cpu_is_at91sam9261())
 50                 clk_disable(hclk);
 51         clocked = 0;
 52 }
 53 
 54 static void at91_start_hc(struct platform_device *pdev)
 55 {
 56         struct usb_hcd *hcd = platform_get_drvdata(pdev);
 57         struct ohci_regs __iomem *regs = hcd->regs;
 58 
 59         dev_dbg(&pdev->dev, "start\n");
 60 
 61         /*
 62          * Start the USB clocks.
 63          */
 64         at91_start_clock();
 65 
 66         /*
 67          * The USB host controller must remain in reset.
 68          */
 69         writel(0, &regs->control);
 70 }
 71 
 72 static void at91_stop_hc(struct platform_device *pdev)
 73 {
 74         struct usb_hcd *hcd = platform_get_drvdata(pdev);
 75         struct ohci_regs __iomem *regs = hcd->regs;
 76 
 77         dev_dbg(&pdev->dev, "stop\n");
 78 
 79         /*
 80          * Put the USB host controller into reset.
 81          */
 82         writel(0, &regs->control);
 83 
 84         /*
 85          * Stop the USB clocks.
 86          */
 87         at91_stop_clock();
 88 }
 89 
 90 
 91 /*-------------------------------------------------------------------------*/
 92 
 93 static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);
 94 
 95 /* configure so an HC device and id are always provided */
 96 /* always called with process context; sleeping is OK */
 97 
 98 
 99 /**
100  * usb_hcd_at91_probe - initialize AT91-based HCDs
101  * Context: !in_interrupt()
102  *
103  * Allocates basic resources for this USB host controller, and
104  * then invokes the start() method for the HCD associated with it
105  * through the hotplug entry's driver_data.
106  */
107 static int usb_hcd_at91_probe(const struct hc_driver *driver,
108                         struct platform_device *pdev)
109 {
110         int retval;
111         struct usb_hcd *hcd = NULL;
112 
113         if (pdev->num_resources != 2) {
114                 pr_debug("hcd probe: invalid num_resources");
115                 return -ENODEV;
116         }
117 
118         if ((pdev->resource[0].flags != IORESOURCE_MEM)
119                         || (pdev->resource[1].flags != IORESOURCE_IRQ)) {
120                 pr_debug("hcd probe: invalid resource type\n");
121                 return -ENODEV;
122         }
123 
124         hcd = usb_create_hcd(driver, &pdev->dev, "at91");
125         if (!hcd)
126                 return -ENOMEM;
127         hcd->rsrc_start = pdev->resource[0].start;
128         hcd->rsrc_len = pdev->resource[0].end - pdev->resource[0].start + 1;
129 
130         if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
131                 pr_debug("request_mem_region failed\n");
132                 retval = -EBUSY;
133                 goto err1;
134         }
135 
136         hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len);
137         if (!hcd->regs) {
138                 pr_debug("ioremap failed\n");
139                 retval = -EIO;
140                 goto err2;
141         }
142 
143         iclk = clk_get(&pdev->dev, "ohci_clk");
144         fclk = clk_get(&pdev->dev, "uhpck");
145         if (cpu_is_at91sam9261())
146                 hclk = clk_get(&pdev->dev, "hck0");
147 
148         at91_start_hc(pdev);
149         ohci_hcd_init(hcd_to_ohci(hcd));
150 
151         retval = usb_add_hcd(hcd, pdev->resource[1].start, IRQF_DISABLED);
152         if (retval == 0)
153                 return retval;
154 
155         /* Error handling */
156         at91_stop_hc(pdev);
157 
158         if (cpu_is_at91sam9261())
159                 clk_put(hclk);
160         clk_put(fclk);
161         clk_put(iclk);
162 
163         iounmap(hcd->regs);
164 
165  err2:
166         release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
167 
168  err1:
169         usb_put_hcd(hcd);
170         return retval;
171 }
172 
173 
174 /* may be called with controller, bus, and devices active */
175 
176 /**
177  * usb_hcd_at91_remove - shutdown processing for AT91-based HCDs
178  * @dev: USB Host Controller being removed
179  * Context: !in_interrupt()
180  *
181  * Reverses the effect of usb_hcd_at91_probe(), first invoking
182  * the HCD's stop() method.  It is always called from a thread
183  * context, "rmmod" or something similar.
184  *
185  */
186 static void usb_hcd_at91_remove(struct usb_hcd *hcd,
187                                 struct platform_device *pdev)
188 {
189         usb_remove_hcd(hcd);
190         at91_stop_hc(pdev);
191         iounmap(hcd->regs);
192         release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
193         usb_put_hcd(hcd);
194 
195         if (cpu_is_at91sam9261())
196                 clk_put(hclk);
197         clk_put(fclk);
198         clk_put(iclk);
199         fclk = iclk = hclk = NULL;
200 
201         dev_set_drvdata(&pdev->dev, NULL);
202 }
203 
204 /*-------------------------------------------------------------------------*/
205 
206 static int __devinit
207 ohci_at91_start (struct usb_hcd *hcd)
208 {
209         struct at91_usbh_data   *board = hcd->self.controller->platform_data;
210         struct ohci_hcd         *ohci = hcd_to_ohci (hcd);
211         int                     ret;
212 
213         if ((ret = ohci_init(ohci)) < 0)
214                 return ret;
215 
216         ohci->num_ports = board->ports;
217 
218         if ((ret = ohci_run(ohci)) < 0) {
219                 err("can't start %s", hcd->self.bus_name);
220                 ohci_stop(hcd);
221                 return ret;
222         }
223         return 0;
224 }
225 
226 /*-------------------------------------------------------------------------*/
227 
228 static const struct hc_driver ohci_at91_hc_driver = {
229         .description =          hcd_name,
230         .product_desc =         "AT91 OHCI",
231         .hcd_priv_size =        sizeof(struct ohci_hcd),
232 
233         /*
234          * generic hardware linkage
235          */
236         .irq =                  ohci_irq,
237         .flags =                HCD_USB11 | HCD_MEMORY,
238 
239         /*
240          * basic lifecycle operations
241          */
242         .start =                ohci_at91_start,
243         .stop =                 ohci_stop,
244         .shutdown =             ohci_shutdown,
245 
246         /*
247          * managing i/o requests and associated device resources
248          */
249         .urb_enqueue =          ohci_urb_enqueue,
250         .urb_dequeue =          ohci_urb_dequeue,
251         .endpoint_disable =     ohci_endpoint_disable,
252 
253         /*
254          * scheduling support
255          */
256         .get_frame_number =     ohci_get_frame,
257 
258         /*
259          * root hub support
260          */
261         .hub_status_data =      ohci_hub_status_data,
262         .hub_control =          ohci_hub_control,
263 #ifdef CONFIG_PM
264         .bus_suspend =          ohci_bus_suspend,
265         .bus_resume =           ohci_bus_resume,
266 #endif
267         .start_port_reset =     ohci_start_port_reset,
268 };
269 
270 /*-------------------------------------------------------------------------*/
271 
272 static int ohci_hcd_at91_drv_probe(struct platform_device *pdev)
273 {
274         struct at91_usbh_data   *pdata = pdev->dev.platform_data;
275         int                     i;
276 
277         if (pdata) {
278                 /* REVISIT make the driver support per-port power switching,
279                  * and also overcurrent detection.  Here we assume the ports
280                  * are always powered while this driver is active, and use
281                  * active-low power switches.
282                  */
283                 for (i = 0; i < ARRAY_SIZE(pdata->vbus_pin); i++) {
284                         if (pdata->vbus_pin[i] <= 0)
285                                 continue;
286                         gpio_request(pdata->vbus_pin[i], "ohci_vbus");
287                         gpio_direction_output(pdata->vbus_pin[i], 0);
288                 }
289         }
290 
291         device_init_wakeup(&pdev->dev, 1);
292         return usb_hcd_at91_probe(&ohci_at91_hc_driver, pdev);
293 }
294 
295 static int ohci_hcd_at91_drv_remove(struct platform_device *pdev)
296 {
297         struct at91_usbh_data   *pdata = pdev->dev.platform_data;
298         int                     i;
299 
300         if (pdata) {
301                 for (i = 0; i < ARRAY_SIZE(pdata->vbus_pin); i++) {
302                         if (pdata->vbus_pin[i] <= 0)
303                                 continue;
304                         gpio_direction_output(pdata->vbus_pin[i], 1);
305                         gpio_free(pdata->vbus_pin[i]);
306                 }
307         }
308 
309         device_init_wakeup(&pdev->dev, 0);
310         usb_hcd_at91_remove(platform_get_drvdata(pdev), pdev);
311         return 0;
312 }
313 
314 #ifdef CONFIG_PM
315 
316 static int
317 ohci_hcd_at91_drv_suspend(struct platform_device *pdev, pm_message_t mesg)
318 {
319         struct usb_hcd  *hcd = platform_get_drvdata(pdev);
320         struct ohci_hcd *ohci = hcd_to_ohci(hcd);
321 
322         if (device_may_wakeup(&pdev->dev))
323                 enable_irq_wake(hcd->irq);
324 
325         /*
326          * The integrated transceivers seem unable to notice disconnect,
327          * reconnect, or wakeup without the 48 MHz clock active.  so for
328          * correctness, always discard connection state (using reset).
329          *
330          * REVISIT: some boards will be able to turn VBUS off...
331          */
332         if (at91_suspend_entering_slow_clock()) {
333                 ohci_usb_reset (ohci);
334                 at91_stop_clock();
335         }
336 
337         return 0;
338 }
339 
340 static int ohci_hcd_at91_drv_resume(struct platform_device *pdev)
341 {
342         struct usb_hcd  *hcd = platform_get_drvdata(pdev);
343 
344         if (device_may_wakeup(&pdev->dev))
345                 disable_irq_wake(hcd->irq);
346 
347         if (!clocked)
348                 at91_start_clock();
349 
350         ohci_finish_controller_resume(hcd);
351         return 0;
352 }
353 #else
354 #define ohci_hcd_at91_drv_suspend NULL
355 #define ohci_hcd_at91_drv_resume  NULL
356 #endif
357 
358 MODULE_ALIAS("platform:at91_ohci");
359 
360 static struct platform_driver ohci_hcd_at91_driver = {
361         .probe          = ohci_hcd_at91_drv_probe,
362         .remove         = ohci_hcd_at91_drv_remove,
363         .shutdown       = usb_hcd_platform_shutdown,
364         .suspend        = ohci_hcd_at91_drv_suspend,
365         .resume         = ohci_hcd_at91_drv_resume,
366         .driver         = {
367                 .name   = "at91_ohci",
368                 .owner  = THIS_MODULE,
369         },
370 };
371 
  This page was automatically generated by the LXR engine.