Linux kernel & device driver programming

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Version: [ 2.6.11.8 ] [ 2.6.25 ] [ 2.6.25.8 ] [ 2.6.31.13 ] Architecture: [ i386 ]
  1 /*
  2  *  Touchscreen driver for Sharp SL-C7xx and SL-Cxx00 models
  3  *
  4  *  Copyright (c) 2004-2005 Richard Purdie
  5  *
  6  *  This program is free software; you can redistribute it and/or modify
  7  *  it under the terms of the GNU General Public License version 2 as
  8  *  published by the Free Software Foundation.
  9  *
 10  */
 11 
 12 
 13 #include <linux/delay.h>
 14 #include <linux/platform_device.h>
 15 #include <linux/init.h>
 16 #include <linux/input.h>
 17 #include <linux/interrupt.h>
 18 #include <linux/module.h>
 19 #include <linux/slab.h>
 20 #include <linux/irq.h>
 21 
 22 #include <mach/sharpsl.h>
 23 #include <mach/hardware.h>
 24 #include <mach/pxa2xx-gpio.h>
 25 
 26 
 27 #define PWR_MODE_ACTIVE         0
 28 #define PWR_MODE_SUSPEND        1
 29 
 30 #define X_AXIS_MAX              3830
 31 #define X_AXIS_MIN              150
 32 #define Y_AXIS_MAX              3830
 33 #define Y_AXIS_MIN              190
 34 #define PRESSURE_MIN            0
 35 #define PRESSURE_MAX            15000
 36 
 37 struct ts_event {
 38         short pressure;
 39         short x;
 40         short y;
 41 };
 42 
 43 struct corgi_ts {
 44         struct input_dev *input;
 45         struct timer_list timer;
 46         struct ts_event tc;
 47         int pendown;
 48         int power_mode;
 49         int irq_gpio;
 50         struct corgits_machinfo *machinfo;
 51 };
 52 
 53 #ifdef CONFIG_PXA25x
 54 #define CCNT(a)         asm volatile ("mrc p14, 0, %0, C1, C0, 0" : "=r"(a))
 55 #define PMNC_GET(x)     asm volatile ("mrc p14, 0, %0, C0, C0, 0" : "=r"(x))
 56 #define PMNC_SET(x)     asm volatile ("mcr p14, 0, %0, C0, C0, 0" : : "r"(x))
 57 #endif
 58 #ifdef CONFIG_PXA27x
 59 #define CCNT(a)         asm volatile ("mrc p14, 0, %0, C1, C1, 0" : "=r"(a))
 60 #define PMNC_GET(x)     asm volatile ("mrc p14, 0, %0, C0, C1, 0" : "=r"(x))
 61 #define PMNC_SET(x)     asm volatile ("mcr p14, 0, %0, C0, C1, 0" : : "r"(x))
 62 #endif
 63 
 64 /* ADS7846 Touch Screen Controller bit definitions */
 65 #define ADSCTRL_PD0             (1u << 0)       /* PD0 */
 66 #define ADSCTRL_PD1             (1u << 1)       /* PD1 */
 67 #define ADSCTRL_DFR             (1u << 2)       /* SER/DFR */
 68 #define ADSCTRL_MOD             (1u << 3)       /* Mode */
 69 #define ADSCTRL_ADR_SH  4       /* Address setting */
 70 #define ADSCTRL_STS             (1u << 7)       /* Start Bit */
 71 
 72 /* External Functions */
 73 extern unsigned int get_clk_frequency_khz(int info);
 74 
 75 static unsigned long calc_waittime(struct corgi_ts *corgi_ts)
 76 {
 77         unsigned long hsync_invperiod = corgi_ts->machinfo->get_hsync_invperiod();
 78 
 79         if (hsync_invperiod)
 80                 return get_clk_frequency_khz(0)*1000/hsync_invperiod;
 81         else
 82                 return 0;
 83 }
 84 
 85 static int sync_receive_data_send_cmd(struct corgi_ts *corgi_ts, int doRecive, int doSend,
 86                 unsigned int address, unsigned long wait_time)
 87 {
 88         unsigned long timer1 = 0, timer2, pmnc = 0;
 89         int pos = 0;
 90 
 91         if (wait_time && doSend) {
 92                 PMNC_GET(pmnc);
 93                 if (!(pmnc & 0x01))
 94                         PMNC_SET(0x01);
 95 
 96                 /* polling HSync */
 97                 corgi_ts->machinfo->wait_hsync();
 98                 /* get CCNT */
 99                 CCNT(timer1);
100         }
101 
102         if (doRecive)
103                 pos = corgi_ssp_ads7846_get();
104 
105         if (doSend) {
106                 int cmd = ADSCTRL_PD0 | ADSCTRL_PD1 | (address << ADSCTRL_ADR_SH) | ADSCTRL_STS;
107                 /* dummy command */
108                 corgi_ssp_ads7846_put(cmd);
109                 corgi_ssp_ads7846_get();
110 
111                 if (wait_time) {
112                         /* Wait after HSync */
113                         CCNT(timer2);
114                         if (timer2-timer1 > wait_time) {
115                                 /* too slow - timeout, try again */
116                                 corgi_ts->machinfo->wait_hsync();
117                                 /* get CCNT */
118                                 CCNT(timer1);
119                                 /* Wait after HSync */
120                                 CCNT(timer2);
121                         }
122                         while (timer2 - timer1 < wait_time)
123                                 CCNT(timer2);
124                 }
125                 corgi_ssp_ads7846_put(cmd);
126                 if (wait_time && !(pmnc & 0x01))
127                         PMNC_SET(pmnc);
128         }
129         return pos;
130 }
131 
132 static int read_xydata(struct corgi_ts *corgi_ts)
133 {
134         unsigned int x, y, z1, z2;
135         unsigned long flags, wait_time;
136 
137         /* critical section */
138         local_irq_save(flags);
139         corgi_ssp_ads7846_lock();
140         wait_time = calc_waittime(corgi_ts);
141 
142         /* Y-axis */
143         sync_receive_data_send_cmd(corgi_ts, 0, 1, 1u, wait_time);
144 
145         /* Y-axis */
146         sync_receive_data_send_cmd(corgi_ts, 1, 1, 1u, wait_time);
147 
148         /* X-axis */
149         y = sync_receive_data_send_cmd(corgi_ts, 1, 1, 5u, wait_time);
150 
151         /* Z1 */
152         x = sync_receive_data_send_cmd(corgi_ts, 1, 1, 3u, wait_time);
153 
154         /* Z2 */
155         z1 = sync_receive_data_send_cmd(corgi_ts, 1, 1, 4u, wait_time);
156         z2 = sync_receive_data_send_cmd(corgi_ts, 1, 0, 4u, wait_time);
157 
158         /* Power-Down Enable */
159         corgi_ssp_ads7846_put((1u << ADSCTRL_ADR_SH) | ADSCTRL_STS);
160         corgi_ssp_ads7846_get();
161 
162         corgi_ssp_ads7846_unlock();
163         local_irq_restore(flags);
164 
165         if (x== 0 || y == 0 || z1 == 0 || (x * (z2 - z1) / z1) >= 15000) {
166                 corgi_ts->tc.pressure = 0;
167                 return 0;
168         }
169 
170         corgi_ts->tc.x = x;
171         corgi_ts->tc.y = y;
172         corgi_ts->tc.pressure = (x * (z2 - z1)) / z1;
173         return 1;
174 }
175 
176 static void new_data(struct corgi_ts *corgi_ts)
177 {
178         struct input_dev *dev = corgi_ts->input;
179 
180         if (corgi_ts->power_mode != PWR_MODE_ACTIVE)
181                 return;
182 
183         if (!corgi_ts->tc.pressure && corgi_ts->pendown == 0)
184                 return;
185 
186         input_report_abs(dev, ABS_X, corgi_ts->tc.x);
187         input_report_abs(dev, ABS_Y, corgi_ts->tc.y);
188         input_report_abs(dev, ABS_PRESSURE, corgi_ts->tc.pressure);
189         input_report_key(dev, BTN_TOUCH, corgi_ts->pendown);
190         input_sync(dev);
191 }
192 
193 static void ts_interrupt_main(struct corgi_ts *corgi_ts, int isTimer)
194 {
195         if ((GPLR(IRQ_TO_GPIO(corgi_ts->irq_gpio)) & GPIO_bit(IRQ_TO_GPIO(corgi_ts->irq_gpio))) == 0) {
196                 /* Disable Interrupt */
197                 set_irq_type(corgi_ts->irq_gpio, IRQ_TYPE_NONE);
198                 if (read_xydata(corgi_ts)) {
199                         corgi_ts->pendown = 1;
200                         new_data(corgi_ts);
201                 }
202                 mod_timer(&corgi_ts->timer, jiffies + HZ / 100);
203         } else {
204                 if (corgi_ts->pendown == 1 || corgi_ts->pendown == 2) {
205                         mod_timer(&corgi_ts->timer, jiffies + HZ / 100);
206                         corgi_ts->pendown++;
207                         return;
208                 }
209 
210                 if (corgi_ts->pendown) {
211                         corgi_ts->tc.pressure = 0;
212                         new_data(corgi_ts);
213                 }
214 
215                 /* Enable Falling Edge */
216                 set_irq_type(corgi_ts->irq_gpio, IRQ_TYPE_EDGE_FALLING);
217                 corgi_ts->pendown = 0;
218         }
219 }
220 
221 static void corgi_ts_timer(unsigned long data)
222 {
223         struct corgi_ts *corgits_data = (struct corgi_ts *) data;
224 
225         ts_interrupt_main(corgits_data, 1);
226 }
227 
228 static irqreturn_t ts_interrupt(int irq, void *dev_id)
229 {
230         struct corgi_ts *corgits_data = dev_id;
231 
232         ts_interrupt_main(corgits_data, 0);
233         return IRQ_HANDLED;
234 }
235 
236 #ifdef CONFIG_PM
237 static int corgits_suspend(struct platform_device *dev, pm_message_t state)
238 {
239         struct corgi_ts *corgi_ts = platform_get_drvdata(dev);
240 
241         if (corgi_ts->pendown) {
242                 del_timer_sync(&corgi_ts->timer);
243                 corgi_ts->tc.pressure = 0;
244                 new_data(corgi_ts);
245                 corgi_ts->pendown = 0;
246         }
247         corgi_ts->power_mode = PWR_MODE_SUSPEND;
248 
249         corgi_ssp_ads7846_putget((1u << ADSCTRL_ADR_SH) | ADSCTRL_STS);
250 
251         return 0;
252 }
253 
254 static int corgits_resume(struct platform_device *dev)
255 {
256         struct corgi_ts *corgi_ts = platform_get_drvdata(dev);
257 
258         corgi_ssp_ads7846_putget((4u << ADSCTRL_ADR_SH) | ADSCTRL_STS);
259         /* Enable Falling Edge */
260         set_irq_type(corgi_ts->irq_gpio, IRQ_TYPE_EDGE_FALLING);
261         corgi_ts->power_mode = PWR_MODE_ACTIVE;
262 
263         return 0;
264 }
265 #else
266 #define corgits_suspend         NULL
267 #define corgits_resume          NULL
268 #endif
269 
270 static int __devinit corgits_probe(struct platform_device *pdev)
271 {
272         struct corgi_ts *corgi_ts;
273         struct input_dev *input_dev;
274         int err = -ENOMEM;
275 
276         corgi_ts = kzalloc(sizeof(struct corgi_ts), GFP_KERNEL);
277         input_dev = input_allocate_device();
278         if (!corgi_ts || !input_dev)
279                 goto fail1;
280 
281         platform_set_drvdata(pdev, corgi_ts);
282 
283         corgi_ts->machinfo = pdev->dev.platform_data;
284         corgi_ts->irq_gpio = platform_get_irq(pdev, 0);
285 
286         if (corgi_ts->irq_gpio < 0) {
287                 err = -ENODEV;
288                 goto fail1;
289         }
290 
291         corgi_ts->input = input_dev;
292 
293         init_timer(&corgi_ts->timer);
294         corgi_ts->timer.data = (unsigned long) corgi_ts;
295         corgi_ts->timer.function = corgi_ts_timer;
296 
297         input_dev->name = "Corgi Touchscreen";
298         input_dev->phys = "corgits/input0";
299         input_dev->id.bustype = BUS_HOST;
300         input_dev->id.vendor = 0x0001;
301         input_dev->id.product = 0x0002;
302         input_dev->id.version = 0x0100;
303         input_dev->dev.parent = &pdev->dev;
304 
305         input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
306         input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
307         input_set_abs_params(input_dev, ABS_X, X_AXIS_MIN, X_AXIS_MAX, 0, 0);
308         input_set_abs_params(input_dev, ABS_Y, Y_AXIS_MIN, Y_AXIS_MAX, 0, 0);
309         input_set_abs_params(input_dev, ABS_PRESSURE, PRESSURE_MIN, PRESSURE_MAX, 0, 0);
310 
311         pxa_gpio_mode(IRQ_TO_GPIO(corgi_ts->irq_gpio) | GPIO_IN);
312 
313         /* Initiaize ADS7846 Difference Reference mode */
314         corgi_ssp_ads7846_putget((1u << ADSCTRL_ADR_SH) | ADSCTRL_STS);
315         mdelay(5);
316         corgi_ssp_ads7846_putget((3u << ADSCTRL_ADR_SH) | ADSCTRL_STS);
317         mdelay(5);
318         corgi_ssp_ads7846_putget((4u << ADSCTRL_ADR_SH) | ADSCTRL_STS);
319         mdelay(5);
320         corgi_ssp_ads7846_putget((5u << ADSCTRL_ADR_SH) | ADSCTRL_STS);
321         mdelay(5);
322 
323         if (request_irq(corgi_ts->irq_gpio, ts_interrupt, IRQF_DISABLED, "ts", corgi_ts)) {
324                 err = -EBUSY;
325                 goto fail1;
326         }
327 
328         err = input_register_device(corgi_ts->input);
329         if (err)
330                 goto fail2;
331 
332         corgi_ts->power_mode = PWR_MODE_ACTIVE;
333 
334         /* Enable Falling Edge */
335         set_irq_type(corgi_ts->irq_gpio, IRQ_TYPE_EDGE_FALLING);
336 
337         return 0;
338 
339  fail2: free_irq(corgi_ts->irq_gpio, corgi_ts);
340  fail1: input_free_device(input_dev);
341         kfree(corgi_ts);
342         return err;
343 }
344 
345 static int __devexit corgits_remove(struct platform_device *pdev)
346 {
347         struct corgi_ts *corgi_ts = platform_get_drvdata(pdev);
348 
349         free_irq(corgi_ts->irq_gpio, corgi_ts);
350         del_timer_sync(&corgi_ts->timer);
351         corgi_ts->machinfo->put_hsync();
352         input_unregister_device(corgi_ts->input);
353         kfree(corgi_ts);
354 
355         return 0;
356 }
357 
358 static struct platform_driver corgits_driver = {
359         .probe          = corgits_probe,
360         .remove         = __devexit_p(corgits_remove),
361         .suspend        = corgits_suspend,
362         .resume         = corgits_resume,
363         .driver         = {
364                 .name   = "corgi-ts",
365                 .owner  = THIS_MODULE,
366         },
367 };
368 
369 static int __init corgits_init(void)
370 {
371         return platform_driver_register(&corgits_driver);
372 }
373 
374 static void __exit corgits_exit(void)
375 {
376         platform_driver_unregister(&corgits_driver);
377 }
378 
379 module_init(corgits_init);
380 module_exit(corgits_exit);
381 
382 MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
383 MODULE_DESCRIPTION("Corgi TouchScreen Driver");
384 MODULE_LICENSE("GPL");
385 MODULE_ALIAS("platform:corgi-ts");
386 
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