1 /*
2 * Atmel Touch Screen Driver
3 *
4 * Copyright (c) 2008 ATMEL
5 * Copyright (c) 2008 Dan Liang
6 * Copyright (c) 2008 TimeSys Corporation
7 * Copyright (c) 2008 Justin Waters
8 *
9 * Based on touchscreen code from Atmel Corporation.
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15 #include <linux/init.h>
16 #include <linux/err.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/input.h>
20 #include <linux/slab.h>
21 #include <linux/interrupt.h>
22 #include <linux/clk.h>
23 #include <linux/platform_device.h>
24 #include <linux/io.h>
25
26 /* Register definitions based on AT91SAM9RL64 preliminary draft datasheet */
27
28 #define ATMEL_TSADCC_CR 0x00 /* Control register */
29 #define ATMEL_TSADCC_SWRST (1 << 0) /* Software Reset*/
30 #define ATMEL_TSADCC_START (1 << 1) /* Start conversion */
31
32 #define ATMEL_TSADCC_MR 0x04 /* Mode register */
33 #define ATMEL_TSADCC_TSAMOD (3 << 0) /* ADC mode */
34 #define ATMEL_TSADCC_TSAMOD_ADC_ONLY_MODE (0x0) /* ADC Mode */
35 #define ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE (0x1) /* Touch Screen Only Mode */
36 #define ATMEL_TSADCC_LOWRES (1 << 4) /* Resolution selection */
37 #define ATMEL_TSADCC_SLEEP (1 << 5) /* Sleep mode */
38 #define ATMEL_TSADCC_PENDET (1 << 6) /* Pen Detect selection */
39 #define ATMEL_TSADCC_PRESCAL (0x3f << 8) /* Prescalar Rate Selection */
40 #define ATMEL_TSADCC_STARTUP (0x7f << 16) /* Start Up time */
41 #define ATMEL_TSADCC_SHTIM (0xf << 24) /* Sample & Hold time */
42 #define ATMEL_TSADCC_PENDBC (0xf << 28) /* Pen Detect debouncing time */
43
44 #define ATMEL_TSADCC_TRGR 0x08 /* Trigger register */
45 #define ATMEL_TSADCC_TRGMOD (7 << 0) /* Trigger mode */
46 #define ATMEL_TSADCC_TRGMOD_NONE (0 << 0)
47 #define ATMEL_TSADCC_TRGMOD_EXT_RISING (1 << 0)
48 #define ATMEL_TSADCC_TRGMOD_EXT_FALLING (2 << 0)
49 #define ATMEL_TSADCC_TRGMOD_EXT_ANY (3 << 0)
50 #define ATMEL_TSADCC_TRGMOD_PENDET (4 << 0)
51 #define ATMEL_TSADCC_TRGMOD_PERIOD (5 << 0)
52 #define ATMEL_TSADCC_TRGMOD_CONTINUOUS (6 << 0)
53 #define ATMEL_TSADCC_TRGPER (0xffff << 16) /* Trigger period */
54
55 #define ATMEL_TSADCC_TSR 0x0C /* Touch Screen register */
56 #define ATMEL_TSADCC_TSFREQ (0xf << 0) /* TS Frequency in Interleaved mode */
57 #define ATMEL_TSADCC_TSSHTIM (0xf << 24) /* Sample & Hold time */
58
59 #define ATMEL_TSADCC_CHER 0x10 /* Channel Enable register */
60 #define ATMEL_TSADCC_CHDR 0x14 /* Channel Disable register */
61 #define ATMEL_TSADCC_CHSR 0x18 /* Channel Status register */
62 #define ATMEL_TSADCC_CH(n) (1 << (n)) /* Channel number */
63
64 #define ATMEL_TSADCC_SR 0x1C /* Status register */
65 #define ATMEL_TSADCC_EOC(n) (1 << ((n)+0)) /* End of conversion for channel N */
66 #define ATMEL_TSADCC_OVRE(n) (1 << ((n)+8)) /* Overrun error for channel N */
67 #define ATMEL_TSADCC_DRDY (1 << 16) /* Data Ready */
68 #define ATMEL_TSADCC_GOVRE (1 << 17) /* General Overrun Error */
69 #define ATMEL_TSADCC_ENDRX (1 << 18) /* End of RX Buffer */
70 #define ATMEL_TSADCC_RXBUFF (1 << 19) /* TX Buffer full */
71 #define ATMEL_TSADCC_PENCNT (1 << 20) /* Pen contact */
72 #define ATMEL_TSADCC_NOCNT (1 << 21) /* No contact */
73
74 #define ATMEL_TSADCC_LCDR 0x20 /* Last Converted Data register */
75 #define ATMEL_TSADCC_DATA (0x3ff << 0) /* Channel data */
76
77 #define ATMEL_TSADCC_IER 0x24 /* Interrupt Enable register */
78 #define ATMEL_TSADCC_IDR 0x28 /* Interrupt Disable register */
79 #define ATMEL_TSADCC_IMR 0x2C /* Interrupt Mask register */
80 #define ATMEL_TSADCC_CDR0 0x30 /* Channel Data 0 */
81 #define ATMEL_TSADCC_CDR1 0x34 /* Channel Data 1 */
82 #define ATMEL_TSADCC_CDR2 0x38 /* Channel Data 2 */
83 #define ATMEL_TSADCC_CDR3 0x3C /* Channel Data 3 */
84 #define ATMEL_TSADCC_CDR4 0x40 /* Channel Data 4 */
85 #define ATMEL_TSADCC_CDR5 0x44 /* Channel Data 5 */
86
87 #define ADC_CLOCK 1000000
88
89 struct atmel_tsadcc {
90 struct input_dev *input;
91 char phys[32];
92 struct clk *clk;
93 int irq;
94 unsigned int prev_absx;
95 unsigned int prev_absy;
96 unsigned char bufferedmeasure;
97 };
98
99 static void __iomem *tsc_base;
100
101 #define atmel_tsadcc_read(reg) __raw_readl(tsc_base + (reg))
102 #define atmel_tsadcc_write(reg, val) __raw_writel((val), tsc_base + (reg))
103
atmel_tsadcc_interrupt(int irq,void * dev)104 static irqreturn_t atmel_tsadcc_interrupt(int irq, void *dev)
105 {
106 struct atmel_tsadcc *ts_dev = (struct atmel_tsadcc *)dev;
107 struct input_dev *input_dev = ts_dev->input;
108
109 unsigned int status;
110 unsigned int reg;
111
112 status = atmel_tsadcc_read(ATMEL_TSADCC_SR);
113 status &= atmel_tsadcc_read(ATMEL_TSADCC_IMR);
114
115 if (status & ATMEL_TSADCC_NOCNT) {
116 /* Contact lost */
117 reg = atmel_tsadcc_read(ATMEL_TSADCC_MR) | ATMEL_TSADCC_PENDBC;
118
119 atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
120 atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE);
121 atmel_tsadcc_write(ATMEL_TSADCC_IDR,
122 ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT);
123 atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT);
124
125 input_report_key(input_dev, BTN_TOUCH, 0);
126 ts_dev->bufferedmeasure = 0;
127 input_sync(input_dev);
128
129 } else if (status & ATMEL_TSADCC_PENCNT) {
130 /* Pen detected */
131 reg = atmel_tsadcc_read(ATMEL_TSADCC_MR);
132 reg &= ~ATMEL_TSADCC_PENDBC;
133
134 atmel_tsadcc_write(ATMEL_TSADCC_IDR, ATMEL_TSADCC_PENCNT);
135 atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
136 atmel_tsadcc_write(ATMEL_TSADCC_IER,
137 ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT);
138 atmel_tsadcc_write(ATMEL_TSADCC_TRGR,
139 ATMEL_TSADCC_TRGMOD_PERIOD | (0x0FFF << 16));
140
141 } else if (status & ATMEL_TSADCC_EOC(3)) {
142 /* Conversion finished */
143
144 if (ts_dev->bufferedmeasure) {
145 /* Last measurement is always discarded, since it can
146 * be erroneous.
147 * Always report previous measurement */
148 input_report_abs(input_dev, ABS_X, ts_dev->prev_absx);
149 input_report_abs(input_dev, ABS_Y, ts_dev->prev_absy);
150 input_report_key(input_dev, BTN_TOUCH, 1);
151 input_sync(input_dev);
152 } else
153 ts_dev->bufferedmeasure = 1;
154
155 /* Now make new measurement */
156 ts_dev->prev_absx = atmel_tsadcc_read(ATMEL_TSADCC_CDR3) << 10;
157 ts_dev->prev_absx /= atmel_tsadcc_read(ATMEL_TSADCC_CDR2);
158
159 ts_dev->prev_absy = atmel_tsadcc_read(ATMEL_TSADCC_CDR1) << 10;
160 ts_dev->prev_absy /= atmel_tsadcc_read(ATMEL_TSADCC_CDR0);
161 }
162
163 return IRQ_HANDLED;
164 }
165
166 /*
167 * The functions for inserting/removing us as a module.
168 */
169
atmel_tsadcc_probe(struct platform_device * pdev)170 static int __devinit atmel_tsadcc_probe(struct platform_device *pdev)
171 {
172 struct atmel_tsadcc *ts_dev;
173 struct input_dev *input_dev;
174 struct resource *res;
175 int err = 0;
176 unsigned int prsc;
177 unsigned int reg;
178
179 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
180 if (!res) {
181 dev_err(&pdev->dev, "no mmio resource defined.\n");
182 return -ENXIO;
183 }
184
185 /* Allocate memory for device */
186 ts_dev = kzalloc(sizeof(struct atmel_tsadcc), GFP_KERNEL);
187 if (!ts_dev) {
188 dev_err(&pdev->dev, "failed to allocate memory.\n");
189 return -ENOMEM;
190 }
191 platform_set_drvdata(pdev, ts_dev);
192
193 input_dev = input_allocate_device();
194 if (!input_dev) {
195 dev_err(&pdev->dev, "failed to allocate input device.\n");
196 err = -EBUSY;
197 goto err_free_mem;
198 }
199
200 ts_dev->irq = platform_get_irq(pdev, 0);
201 if (ts_dev->irq < 0) {
202 dev_err(&pdev->dev, "no irq ID is designated.\n");
203 err = -ENODEV;
204 goto err_free_dev;
205 }
206
207 if (!request_mem_region(res->start, res->end - res->start + 1,
208 "atmel tsadcc regs")) {
209 dev_err(&pdev->dev, "resources is unavailable.\n");
210 err = -EBUSY;
211 goto err_free_dev;
212 }
213
214 tsc_base = ioremap(res->start, res->end - res->start + 1);
215 if (!tsc_base) {
216 dev_err(&pdev->dev, "failed to map registers.\n");
217 err = -ENOMEM;
218 goto err_release_mem;
219 }
220
221 err = request_irq(ts_dev->irq, atmel_tsadcc_interrupt, IRQF_DISABLED,
222 pdev->dev.driver->name, ts_dev);
223 if (err) {
224 dev_err(&pdev->dev, "failed to allocate irq.\n");
225 goto err_unmap_regs;
226 }
227
228 ts_dev->clk = clk_get(&pdev->dev, "tsc_clk");
229 if (IS_ERR(ts_dev->clk)) {
230 dev_err(&pdev->dev, "failed to get ts_clk\n");
231 err = PTR_ERR(ts_dev->clk);
232 goto err_free_irq;
233 }
234
235 ts_dev->input = input_dev;
236 ts_dev->bufferedmeasure = 0;
237
238 snprintf(ts_dev->phys, sizeof(ts_dev->phys),
239 "%s/input0", dev_name(&pdev->dev));
240
241 input_dev->name = "atmel touch screen controller";
242 input_dev->phys = ts_dev->phys;
243 input_dev->dev.parent = &pdev->dev;
244
245 input_dev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
246 input_dev->keybit[BIT_WORD(BTN_TOUCH)] = BIT_MASK(BTN_TOUCH);
247
248 input_set_abs_params(input_dev, ABS_X, 0, 0x3FF, 0, 0);
249 input_set_abs_params(input_dev, ABS_Y, 0, 0x3FF, 0, 0);
250
251 /* clk_enable() always returns 0, no need to check it */
252 clk_enable(ts_dev->clk);
253
254 prsc = clk_get_rate(ts_dev->clk);
255 dev_info(&pdev->dev, "Master clock is set at: %d Hz\n", prsc);
256
257 prsc = prsc / ADC_CLOCK / 2 - 1;
258
259 reg = ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE |
260 ((0x00 << 5) & ATMEL_TSADCC_SLEEP) | /* Normal Mode */
261 ((0x01 << 6) & ATMEL_TSADCC_PENDET) | /* Enable Pen Detect */
262 ((prsc << 8) & ATMEL_TSADCC_PRESCAL) | /* PRESCAL */
263 ((0x13 << 16) & ATMEL_TSADCC_STARTUP) | /* STARTUP */
264 ((0x0F << 28) & ATMEL_TSADCC_PENDBC); /* PENDBC */
265
266 atmel_tsadcc_write(ATMEL_TSADCC_CR, ATMEL_TSADCC_SWRST);
267 atmel_tsadcc_write(ATMEL_TSADCC_MR, reg);
268 atmel_tsadcc_write(ATMEL_TSADCC_TRGR, ATMEL_TSADCC_TRGMOD_NONE);
269 atmel_tsadcc_write(ATMEL_TSADCC_TSR, (0x3 << 24) & ATMEL_TSADCC_TSSHTIM);
270
271 atmel_tsadcc_read(ATMEL_TSADCC_SR);
272 atmel_tsadcc_write(ATMEL_TSADCC_IER, ATMEL_TSADCC_PENCNT);
273
274 /* All went ok, so register to the input system */
275 err = input_register_device(input_dev);
276 if (err)
277 goto err_fail;
278
279 return 0;
280
281 err_fail:
282 clk_disable(ts_dev->clk);
283 clk_put(ts_dev->clk);
284 err_free_irq:
285 free_irq(ts_dev->irq, ts_dev);
286 err_unmap_regs:
287 iounmap(tsc_base);
288 err_release_mem:
289 release_mem_region(res->start, res->end - res->start + 1);
290 err_free_dev:
291 input_free_device(ts_dev->input);
292 err_free_mem:
293 kfree(ts_dev);
294 return err;
295 }
296
atmel_tsadcc_remove(struct platform_device * pdev)297 static int __devexit atmel_tsadcc_remove(struct platform_device *pdev)
298 {
299 struct atmel_tsadcc *ts_dev = dev_get_drvdata(&pdev->dev);
300 struct resource *res;
301
302 free_irq(ts_dev->irq, ts_dev);
303
304 input_unregister_device(ts_dev->input);
305
306 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
307 iounmap(tsc_base);
308 release_mem_region(res->start, res->end - res->start + 1);
309
310 clk_disable(ts_dev->clk);
311 clk_put(ts_dev->clk);
312
313 kfree(ts_dev);
314
315 return 0;
316 }
317
318 static struct platform_driver atmel_tsadcc_driver = {
319 .probe = atmel_tsadcc_probe,
320 .remove = __devexit_p(atmel_tsadcc_remove),
321 .driver = {
322 .name = "atmel_tsadcc",
323 },
324 };
325
atmel_tsadcc_init(void)326 static int __init atmel_tsadcc_init(void)
327 {
328 return platform_driver_register(&atmel_tsadcc_driver);
329 }
330
atmel_tsadcc_exit(void)331 static void __exit atmel_tsadcc_exit(void)
332 {
333 platform_driver_unregister(&atmel_tsadcc_driver);
334 }
335
336 module_init(atmel_tsadcc_init);
337 module_exit(atmel_tsadcc_exit);
338
339
340 MODULE_LICENSE("GPL");
341 MODULE_DESCRIPTION("Atmel TouchScreen Driver");
342 MODULE_AUTHOR("Dan Liang <dan.liang@atmel.com>");
343
344