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atmel-wm97xx.c
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1 /*
2  * Atmel AT91 and AVR32 continuous touch screen driver for Wolfson WM97xx AC97
3  * codecs.
4  *
5  * Copyright (C) 2008 - 2009 Atmel Corporation
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms of the GNU General Public License version 2 as published by
9  * the Free Software Foundation.
10  */
11 #include <linux/module.h>
12 #include <linux/moduleparam.h>
13 #include <linux/kernel.h>
14 #include <linux/init.h>
15 #include <linux/delay.h>
16 #include <linux/irq.h>
17 #include <linux/interrupt.h>
18 #include <linux/wm97xx.h>
19 #include <linux/timer.h>
20 #include <linux/gpio.h>
21 #include <linux/io.h>
22 #include <linux/slab.h>
23 
24 #define AC97C_ICA 0x10
25 #define AC97C_CBRHR 0x30
26 #define AC97C_CBSR 0x38
27 #define AC97C_CBMR 0x3c
28 #define AC97C_IER 0x54
29 #define AC97C_IDR 0x58
30 
31 #define AC97C_RXRDY (1 << 4)
32 #define AC97C_OVRUN (1 << 5)
33 
34 #define AC97C_CMR_SIZE_20 (0 << 16)
35 #define AC97C_CMR_SIZE_18 (1 << 16)
36 #define AC97C_CMR_SIZE_16 (2 << 16)
37 #define AC97C_CMR_SIZE_10 (3 << 16)
38 #define AC97C_CMR_CEM_LITTLE (1 << 18)
39 #define AC97C_CMR_CEM_BIG (0 << 18)
40 #define AC97C_CMR_CENA (1 << 21)
41 
42 #define AC97C_INT_CBEVT (1 << 4)
43 
44 #define AC97C_SR_CAEVT (1 << 3)
45 
46 #define AC97C_CH_MASK(slot) \
47  (0x7 << (3 * (slot - 3)))
48 #define AC97C_CH_ASSIGN(slot, channel) \
49  (AC97C_CHANNEL_##channel << (3 * (slot - 3)))
50 #define AC97C_CHANNEL_NONE 0x0
51 #define AC97C_CHANNEL_B 0x2
52 
53 #define ac97c_writel(chip, reg, val) \
54  __raw_writel((val), (chip)->regs + AC97C_##reg)
55 #define ac97c_readl(chip, reg) \
56  __raw_readl((chip)->regs + AC97C_##reg)
57 
58 #ifdef CONFIG_CPU_AT32AP700X
59 #define ATMEL_WM97XX_AC97C_IOMEM (0xfff02800)
60 #define ATMEL_WM97XX_AC97C_IRQ (29)
61 #define ATMEL_WM97XX_GPIO_DEFAULT (32+16) /* Pin 16 on port B. */
62 #else
63 #error Unknown CPU, this driver only supports AT32AP700X CPUs.
64 #endif
65 
66 struct continuous {
67  u16 id; /* codec id */
68  u8 code; /* continuous code */
69  u8 reads; /* number of coord reads per read cycle */
70  u32 speed; /* number of coords per second */
71 };
72 
73 #define WM_READS(sp) ((sp / HZ) + 1)
74 
75 static const struct continuous cinfo[] = {
76  {WM9705_ID2, 0, WM_READS(94), 94},
77  {WM9705_ID2, 1, WM_READS(188), 188},
78  {WM9705_ID2, 2, WM_READS(375), 375},
79  {WM9705_ID2, 3, WM_READS(750), 750},
80  {WM9712_ID2, 0, WM_READS(94), 94},
81  {WM9712_ID2, 1, WM_READS(188), 188},
82  {WM9712_ID2, 2, WM_READS(375), 375},
83  {WM9712_ID2, 3, WM_READS(750), 750},
84  {WM9713_ID2, 0, WM_READS(94), 94},
85  {WM9713_ID2, 1, WM_READS(120), 120},
86  {WM9713_ID2, 2, WM_READS(154), 154},
87  {WM9713_ID2, 3, WM_READS(188), 188},
88 };
89 
90 /* Continuous speed index. */
91 static int sp_idx;
92 
93 /*
94  * Pen sampling frequency (Hz) in continuous mode.
95  */
96 static int cont_rate = 188;
97 module_param(cont_rate, int, 0);
98 MODULE_PARM_DESC(cont_rate, "Sampling rate in continuous mode (Hz)");
99 
100 /*
101  * Pen down detection.
102  *
103  * This driver can either poll or use an interrupt to indicate a pen down
104  * event. If the irq request fails then it will fall back to polling mode.
105  */
106 static int pen_int = 1;
107 module_param(pen_int, int, 0);
108 MODULE_PARM_DESC(pen_int, "Pen down detection (1 = interrupt, 0 = polling)");
109 
110 /*
111  * Pressure readback.
112  *
113  * Set to 1 to read back pen down pressure.
114  */
115 static int pressure;
116 module_param(pressure, int, 0);
117 MODULE_PARM_DESC(pressure, "Pressure readback (1 = pressure, 0 = no pressure)");
118 
119 /*
120  * AC97 touch data slot.
121  *
122  * Touch screen readback data ac97 slot.
123  */
124 static int ac97_touch_slot = 5;
125 module_param(ac97_touch_slot, int, 0);
126 MODULE_PARM_DESC(ac97_touch_slot, "Touch screen data slot AC97 number");
127 
128 /*
129  * GPIO line number.
130  *
131  * Set to GPIO number where the signal from the WM97xx device is hooked up.
132  */
133 static int atmel_gpio_line = ATMEL_WM97XX_GPIO_DEFAULT;
134 module_param(atmel_gpio_line, int, 0);
135 MODULE_PARM_DESC(atmel_gpio_line, "GPIO line number connected to WM97xx");
136 
137 struct atmel_wm97xx {
138  struct wm97xx *wm;
139  struct timer_list pen_timer;
140  void __iomem *regs;
141  unsigned long ac97c_irq;
142  unsigned long gpio_pen;
143  unsigned long gpio_irq;
144  unsigned short x;
145  unsigned short y;
146 };
147 
148 static irqreturn_t atmel_wm97xx_channel_b_interrupt(int irq, void *dev_id)
149 {
150  struct atmel_wm97xx *atmel_wm97xx = dev_id;
151  struct wm97xx *wm = atmel_wm97xx->wm;
152  int status = ac97c_readl(atmel_wm97xx, CBSR);
153  irqreturn_t retval = IRQ_NONE;
154 
155  if (status & AC97C_OVRUN) {
156  dev_dbg(&wm->touch_dev->dev, "AC97C overrun\n");
157  ac97c_readl(atmel_wm97xx, CBRHR);
158  retval = IRQ_HANDLED;
159  } else if (status & AC97C_RXRDY) {
160  u16 data;
161  u16 value;
162  u16 source;
163  u16 pen_down;
164 
165  data = ac97c_readl(atmel_wm97xx, CBRHR);
166  value = data & 0x0fff;
167  source = data & WM97XX_ADCSEL_MASK;
168  pen_down = (data & WM97XX_PEN_DOWN) >> 8;
169 
170  if (source == WM97XX_ADCSEL_X)
171  atmel_wm97xx->x = value;
172  if (source == WM97XX_ADCSEL_Y)
173  atmel_wm97xx->y = value;
174 
175  if (!pressure && source == WM97XX_ADCSEL_Y) {
176  input_report_abs(wm->input_dev, ABS_X, atmel_wm97xx->x);
177  input_report_abs(wm->input_dev, ABS_Y, atmel_wm97xx->y);
178  input_report_key(wm->input_dev, BTN_TOUCH, pen_down);
179  input_sync(wm->input_dev);
180  } else if (pressure && source == WM97XX_ADCSEL_PRES) {
181  input_report_abs(wm->input_dev, ABS_X, atmel_wm97xx->x);
182  input_report_abs(wm->input_dev, ABS_Y, atmel_wm97xx->y);
183  input_report_abs(wm->input_dev, ABS_PRESSURE, value);
184  input_report_key(wm->input_dev, BTN_TOUCH, value);
185  input_sync(wm->input_dev);
186  }
187 
188  retval = IRQ_HANDLED;
189  }
190 
191  return retval;
192 }
193 
194 static void atmel_wm97xx_acc_pen_up(struct wm97xx *wm)
195 {
196  struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(wm->touch_dev);
197  struct input_dev *input_dev = wm->input_dev;
198  int pen_down = gpio_get_value(atmel_wm97xx->gpio_pen);
199 
200  if (pen_down != 0) {
201  mod_timer(&atmel_wm97xx->pen_timer,
202  jiffies + msecs_to_jiffies(1));
203  } else {
204  if (pressure)
205  input_report_abs(input_dev, ABS_PRESSURE, 0);
206  input_report_key(input_dev, BTN_TOUCH, 0);
207  input_sync(input_dev);
208  }
209 }
210 
211 static void atmel_wm97xx_pen_timer(unsigned long data)
212 {
213  atmel_wm97xx_acc_pen_up((struct wm97xx *)data);
214 }
215 
216 static int atmel_wm97xx_acc_startup(struct wm97xx *wm)
217 {
218  struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(wm->touch_dev);
219  int idx = 0;
220 
221  if (wm->ac97 == NULL)
222  return -ENODEV;
223 
224  for (idx = 0; idx < ARRAY_SIZE(cinfo); idx++) {
225  if (wm->id != cinfo[idx].id)
226  continue;
227 
228  sp_idx = idx;
229 
230  if (cont_rate <= cinfo[idx].speed)
231  break;
232  }
233 
234  wm->acc_rate = cinfo[sp_idx].code;
235  wm->acc_slot = ac97_touch_slot;
236  dev_info(&wm->touch_dev->dev, "atmel accelerated touchscreen driver, "
237  "%d samples/sec\n", cinfo[sp_idx].speed);
238 
239  if (pen_int) {
240  unsigned long reg;
241 
242  wm->pen_irq = atmel_wm97xx->gpio_irq;
243 
244  switch (wm->id) {
245  case WM9712_ID2: /* Fall through. */
246  case WM9713_ID2:
247  /*
248  * Use GPIO 13 (PEN_DOWN) to assert GPIO line 3
249  * (PENDOWN).
250  */
251  wm97xx_config_gpio(wm, WM97XX_GPIO_13, WM97XX_GPIO_IN,
252  WM97XX_GPIO_POL_HIGH,
253  WM97XX_GPIO_STICKY,
254  WM97XX_GPIO_WAKE);
255  wm97xx_config_gpio(wm, WM97XX_GPIO_3, WM97XX_GPIO_OUT,
256  WM97XX_GPIO_POL_HIGH,
257  WM97XX_GPIO_NOTSTICKY,
258  WM97XX_GPIO_NOWAKE);
259  case WM9705_ID2: /* Fall through. */
260  /*
261  * Enable touch data slot in AC97 controller channel B.
262  */
263  reg = ac97c_readl(atmel_wm97xx, ICA);
264  reg &= ~AC97C_CH_MASK(wm->acc_slot);
265  reg |= AC97C_CH_ASSIGN(wm->acc_slot, B);
266  ac97c_writel(atmel_wm97xx, ICA, reg);
267 
268  /*
269  * Enable channel and interrupt for RXRDY and OVERRUN.
270  */
271  ac97c_writel(atmel_wm97xx, CBMR, AC97C_CMR_CENA
272  | AC97C_CMR_CEM_BIG
273  | AC97C_CMR_SIZE_16
274  | AC97C_OVRUN
275  | AC97C_RXRDY);
276  /* Dummy read to empty RXRHR. */
277  ac97c_readl(atmel_wm97xx, CBRHR);
278  /*
279  * Enable interrupt for channel B in the AC97
280  * controller.
281  */
282  ac97c_writel(atmel_wm97xx, IER, AC97C_INT_CBEVT);
283  break;
284  default:
285  dev_err(&wm->touch_dev->dev, "pen down irq not "
286  "supported on this device\n");
287  pen_int = 0;
288  break;
289  }
290  }
291 
292  return 0;
293 }
294 
295 static void atmel_wm97xx_acc_shutdown(struct wm97xx *wm)
296 {
297  if (pen_int) {
298  struct atmel_wm97xx *atmel_wm97xx =
299  platform_get_drvdata(wm->touch_dev);
300  unsigned long ica;
301 
302  switch (wm->id & 0xffff) {
303  case WM9705_ID2: /* Fall through. */
304  case WM9712_ID2: /* Fall through. */
305  case WM9713_ID2:
306  /* Disable slot and turn off channel B interrupts. */
307  ica = ac97c_readl(atmel_wm97xx, ICA);
308  ica &= ~AC97C_CH_MASK(wm->acc_slot);
309  ac97c_writel(atmel_wm97xx, ICA, ica);
310  ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
311  ac97c_writel(atmel_wm97xx, CBMR, 0);
312  wm->pen_irq = 0;
313  break;
314  default:
315  dev_err(&wm->touch_dev->dev, "unknown codec\n");
316  break;
317  }
318  }
319 }
320 
321 static void atmel_wm97xx_irq_enable(struct wm97xx *wm, int enable)
322 {
323  /* Intentionally left empty. */
324 }
325 
326 static struct wm97xx_mach_ops atmel_mach_ops = {
327  .acc_enabled = 1,
328  .acc_pen_up = atmel_wm97xx_acc_pen_up,
329  .acc_startup = atmel_wm97xx_acc_startup,
330  .acc_shutdown = atmel_wm97xx_acc_shutdown,
331  .irq_enable = atmel_wm97xx_irq_enable,
332  .irq_gpio = WM97XX_GPIO_3,
333 };
334 
335 static int __init atmel_wm97xx_probe(struct platform_device *pdev)
336 {
337  struct wm97xx *wm = platform_get_drvdata(pdev);
338  struct atmel_wm97xx *atmel_wm97xx;
339  int ret;
340 
341  atmel_wm97xx = kzalloc(sizeof(struct atmel_wm97xx), GFP_KERNEL);
342  if (!atmel_wm97xx) {
343  dev_dbg(&pdev->dev, "out of memory\n");
344  return -ENOMEM;
345  }
346 
347  atmel_wm97xx->wm = wm;
348  atmel_wm97xx->regs = (void *)ATMEL_WM97XX_AC97C_IOMEM;
349  atmel_wm97xx->ac97c_irq = ATMEL_WM97XX_AC97C_IRQ;
350  atmel_wm97xx->gpio_pen = atmel_gpio_line;
351  atmel_wm97xx->gpio_irq = gpio_to_irq(atmel_wm97xx->gpio_pen);
352 
353  setup_timer(&atmel_wm97xx->pen_timer, atmel_wm97xx_pen_timer,
354  (unsigned long)wm);
355 
356  ret = request_irq(atmel_wm97xx->ac97c_irq,
357  atmel_wm97xx_channel_b_interrupt,
358  IRQF_SHARED, "atmel-wm97xx-ch-b", atmel_wm97xx);
359  if (ret) {
360  dev_dbg(&pdev->dev, "could not request ac97c irq\n");
361  goto err;
362  }
363 
364  platform_set_drvdata(pdev, atmel_wm97xx);
365 
366  ret = wm97xx_register_mach_ops(wm, &atmel_mach_ops);
367  if (ret)
368  goto err_irq;
369 
370  return ret;
371 
372 err_irq:
373  free_irq(atmel_wm97xx->ac97c_irq, atmel_wm97xx);
374 err:
375  platform_set_drvdata(pdev, NULL);
376  kfree(atmel_wm97xx);
377  return ret;
378 }
379 
380 static int __exit atmel_wm97xx_remove(struct platform_device *pdev)
381 {
382  struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
383  struct wm97xx *wm = atmel_wm97xx->wm;
384 
385  ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
386  free_irq(atmel_wm97xx->ac97c_irq, atmel_wm97xx);
387  del_timer_sync(&atmel_wm97xx->pen_timer);
388  wm97xx_unregister_mach_ops(wm);
389  platform_set_drvdata(pdev, NULL);
390  kfree(atmel_wm97xx);
391 
392  return 0;
393 }
394 
395 #ifdef CONFIG_PM_SLEEP
396 static int atmel_wm97xx_suspend(struct *dev)
397 {
398  struct platform_device *pdev = to_platform_device(dev);
399  struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
400 
401  ac97c_writel(atmel_wm97xx, IDR, AC97C_INT_CBEVT);
402  disable_irq(atmel_wm97xx->gpio_irq);
403  del_timer_sync(&atmel_wm97xx->pen_timer);
404 
405  return 0;
406 }
407 
408 static int atmel_wm97xx_resume(struct device *dev)
409 {
410  struct platform_device *pdev = to_platform_device(dev);
411  struct atmel_wm97xx *atmel_wm97xx = platform_get_drvdata(pdev);
412  struct wm97xx *wm = atmel_wm97xx->wm;
413 
414  if (wm->input_dev->users) {
415  enable_irq(atmel_wm97xx->gpio_irq);
416  ac97c_writel(atmel_wm97xx, IER, AC97C_INT_CBEVT);
417  }
418 
419  return 0;
420 }
421 #endif
422 
423 static SIMPLE_DEV_PM_OPS(atmel_wm97xx_pm_ops,
424  atmel_wm97xx_suspend, atmel_wm97xx_resume);
425 
426 static struct platform_driver atmel_wm97xx_driver = {
427  .remove = __exit_p(atmel_wm97xx_remove),
428  .driver = {
429  .name = "wm97xx-touch",
430  .owner = THIS_MODULE,
431  .pm = &atmel_wm97xx_pm_ops,
432  },
433 };
434 
435 static int __init atmel_wm97xx_init(void)
436 {
437  return platform_driver_probe(&atmel_wm97xx_driver, atmel_wm97xx_probe);
438 }
439 module_init(atmel_wm97xx_init);
440 
441 static void __exit atmel_wm97xx_exit(void)
442 {
443  platform_driver_unregister(&atmel_wm97xx_driver);
444 }
445 module_exit(atmel_wm97xx_exit);
446 
447 MODULE_AUTHOR("Hans-Christian Egtvedt <[email protected]>");
448 MODULE_DESCRIPTION("wm97xx continuous touch driver for Atmel AT91 and AVR32");
449 MODULE_LICENSE("GPL");
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