2 * Atmel Touch Screen Driver
4 * Copyright (c) 2008 ATMEL
5 * Copyright (c) 2008 Dan Liang
6 * Copyright (c) 2008 TimeSys Corporation
7 * Copyright (c) 2008 Justin Waters
9 * Based on touchscreen code from Atmel Corporation.
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.
15 #include <linux/err.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/input.h>
19 #include <linux/slab.h>
20 #include <linux/interrupt.h>
21 #include <linux/clk.h>
22 #include <linux/platform_device.h>
24 #include <linux/platform_data/atmel.h>
27 /* Register definitions based on AT91SAM9RL64 preliminary draft datasheet */
29 #define ATMEL_TSADCC_CR 0x00 /* Control register */
30 #define ATMEL_TSADCC_SWRST (1 << 0) /* Software Reset*/
31 #define ATMEL_TSADCC_START (1 << 1) /* Start conversion */
33 #define ATMEL_TSADCC_MR 0x04 /* Mode register */
34 #define ATMEL_TSADCC_TSAMOD (3 << 0) /* ADC mode */
35 #define ATMEL_TSADCC_TSAMOD_ADC_ONLY_MODE (0x0) /* ADC Mode */
36 #define ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE (0x1) /* Touch Screen Only Mode */
37 #define ATMEL_TSADCC_LOWRES (1 << 4) /* Resolution selection */
38 #define ATMEL_TSADCC_SLEEP (1 << 5) /* Sleep mode */
39 #define ATMEL_TSADCC_PENDET (1 << 6) /* Pen Detect selection */
40 #define ATMEL_TSADCC_PRES (1 << 7) /* Pressure Measurement Selection */
41 #define ATMEL_TSADCC_PRESCAL (0x3f << 8) /* Prescalar Rate Selection */
42 #define ATMEL_TSADCC_EPRESCAL (0xff << 8) /* Prescalar Rate Selection (Extended) */
43 #define ATMEL_TSADCC_STARTUP (0x7f << 16) /* Start Up time */
44 #define ATMEL_TSADCC_SHTIM (0xf << 24) /* Sample & Hold time */
45 #define ATMEL_TSADCC_PENDBC (0xf << 28) /* Pen Detect debouncing time */
47 #define ATMEL_TSADCC_TRGR 0x08 /* Trigger register */
48 #define ATMEL_TSADCC_TRGMOD (7 << 0) /* Trigger mode */
49 #define ATMEL_TSADCC_TRGMOD_NONE (0 << 0)
50 #define ATMEL_TSADCC_TRGMOD_EXT_RISING (1 << 0)
51 #define ATMEL_TSADCC_TRGMOD_EXT_FALLING (2 << 0)
52 #define ATMEL_TSADCC_TRGMOD_EXT_ANY (3 << 0)
53 #define ATMEL_TSADCC_TRGMOD_PENDET (4 << 0)
54 #define ATMEL_TSADCC_TRGMOD_PERIOD (5 << 0)
55 #define ATMEL_TSADCC_TRGMOD_CONTINUOUS (6 << 0)
56 #define ATMEL_TSADCC_TRGPER (0xffff << 16) /* Trigger period */
58 #define ATMEL_TSADCC_TSR 0x0C /* Touch Screen register */
59 #define ATMEL_TSADCC_TSFREQ (0xf << 0) /* TS Frequency in Interleaved mode */
60 #define ATMEL_TSADCC_TSSHTIM (0xf << 24) /* Sample & Hold time */
62 #define ATMEL_TSADCC_CHER 0x10 /* Channel Enable register */
63 #define ATMEL_TSADCC_CHDR 0x14 /* Channel Disable register */
64 #define ATMEL_TSADCC_CHSR 0x18 /* Channel Status register */
65 #define ATMEL_TSADCC_CH(n) (1 << (n)) /* Channel number */
67 #define ATMEL_TSADCC_SR 0x1C /* Status register */
68 #define ATMEL_TSADCC_EOC(n) (1 << ((n)+0)) /* End of conversion for channel N */
69 #define ATMEL_TSADCC_OVRE(n) (1 << ((n)+8)) /* Overrun error for channel N */
70 #define ATMEL_TSADCC_DRDY (1 << 16) /* Data Ready */
71 #define ATMEL_TSADCC_GOVRE (1 << 17) /* General Overrun Error */
72 #define ATMEL_TSADCC_ENDRX (1 << 18) /* End of RX Buffer */
73 #define ATMEL_TSADCC_RXBUFF (1 << 19) /* TX Buffer full */
74 #define ATMEL_TSADCC_PENCNT (1 << 20) /* Pen contact */
75 #define ATMEL_TSADCC_NOCNT (1 << 21) /* No contact */
77 #define ATMEL_TSADCC_LCDR 0x20 /* Last Converted Data register */
78 #define ATMEL_TSADCC_DATA (0x3ff << 0) /* Channel data */
80 #define ATMEL_TSADCC_IER 0x24 /* Interrupt Enable register */
81 #define ATMEL_TSADCC_IDR 0x28 /* Interrupt Disable register */
82 #define ATMEL_TSADCC_IMR 0x2C /* Interrupt Mask register */
83 #define ATMEL_TSADCC_CDR0 0x30 /* Channel Data 0 */
84 #define ATMEL_TSADCC_CDR1 0x34 /* Channel Data 1 */
85 #define ATMEL_TSADCC_CDR2 0x38 /* Channel Data 2 */
86 #define ATMEL_TSADCC_CDR3 0x3C /* Channel Data 3 */
87 #define ATMEL_TSADCC_CDR4 0x40 /* Channel Data 4 */
88 #define ATMEL_TSADCC_CDR5 0x44 /* Channel Data 5 */
90 #define ATMEL_TSADCC_XPOS 0x50
91 #define ATMEL_TSADCC_Z1DAT 0x54
92 #define ATMEL_TSADCC_Z2DAT 0x58
94 #define PRESCALER_VAL(x) ((x) >> 8)
96 #define ADC_DEFAULT_CLOCK 100000
99 struct input_dev
*input
;
103 unsigned int prev_absx
;
104 unsigned int prev_absy
;
105 unsigned char bufferedmeasure
;
108 static void __iomem
*tsc_base
;
110 #define atmel_tsadcc_read(reg) __raw_readl(tsc_base + (reg))
111 #define atmel_tsadcc_write(reg, val) __raw_writel((val), tsc_base + (reg))
113 static irqreturn_t
atmel_tsadcc_interrupt(int irq
, void *dev
)
115 struct atmel_tsadcc
*ts_dev
= (struct atmel_tsadcc
*)dev
;
116 struct input_dev
*input_dev
= ts_dev
->input
;
121 status
= atmel_tsadcc_read(ATMEL_TSADCC_SR
);
122 status
&= atmel_tsadcc_read(ATMEL_TSADCC_IMR
);
124 if (status
& ATMEL_TSADCC_NOCNT
) {
126 reg
= atmel_tsadcc_read(ATMEL_TSADCC_MR
) | ATMEL_TSADCC_PENDBC
;
128 atmel_tsadcc_write(ATMEL_TSADCC_MR
, reg
);
129 atmel_tsadcc_write(ATMEL_TSADCC_TRGR
, ATMEL_TSADCC_TRGMOD_NONE
);
130 atmel_tsadcc_write(ATMEL_TSADCC_IDR
,
131 ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT
);
132 atmel_tsadcc_write(ATMEL_TSADCC_IER
, ATMEL_TSADCC_PENCNT
);
134 input_report_key(input_dev
, BTN_TOUCH
, 0);
135 ts_dev
->bufferedmeasure
= 0;
136 input_sync(input_dev
);
138 } else if (status
& ATMEL_TSADCC_PENCNT
) {
140 reg
= atmel_tsadcc_read(ATMEL_TSADCC_MR
);
141 reg
&= ~ATMEL_TSADCC_PENDBC
;
143 atmel_tsadcc_write(ATMEL_TSADCC_IDR
, ATMEL_TSADCC_PENCNT
);
144 atmel_tsadcc_write(ATMEL_TSADCC_MR
, reg
);
145 atmel_tsadcc_write(ATMEL_TSADCC_IER
,
146 ATMEL_TSADCC_EOC(3) | ATMEL_TSADCC_NOCNT
);
147 atmel_tsadcc_write(ATMEL_TSADCC_TRGR
,
148 ATMEL_TSADCC_TRGMOD_PERIOD
| (0x0FFF << 16));
150 } else if (status
& ATMEL_TSADCC_EOC(3)) {
151 /* Conversion finished */
153 if (ts_dev
->bufferedmeasure
) {
154 /* Last measurement is always discarded, since it can
156 * Always report previous measurement */
157 input_report_abs(input_dev
, ABS_X
, ts_dev
->prev_absx
);
158 input_report_abs(input_dev
, ABS_Y
, ts_dev
->prev_absy
);
159 input_report_key(input_dev
, BTN_TOUCH
, 1);
160 input_sync(input_dev
);
162 ts_dev
->bufferedmeasure
= 1;
164 /* Now make new measurement */
165 ts_dev
->prev_absx
= atmel_tsadcc_read(ATMEL_TSADCC_CDR3
) << 10;
166 ts_dev
->prev_absx
/= atmel_tsadcc_read(ATMEL_TSADCC_CDR2
);
168 ts_dev
->prev_absy
= atmel_tsadcc_read(ATMEL_TSADCC_CDR1
) << 10;
169 ts_dev
->prev_absy
/= atmel_tsadcc_read(ATMEL_TSADCC_CDR0
);
176 * The functions for inserting/removing us as a module.
179 static int atmel_tsadcc_probe(struct platform_device
*pdev
)
181 struct atmel_tsadcc
*ts_dev
;
182 struct input_dev
*input_dev
;
183 struct resource
*res
;
184 struct at91_tsadcc_data
*pdata
= dev_get_platdata(&pdev
->dev
);
192 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
194 dev_err(&pdev
->dev
, "no mmio resource defined.\n");
198 /* Allocate memory for device */
199 ts_dev
= kzalloc(sizeof(struct atmel_tsadcc
), GFP_KERNEL
);
201 dev_err(&pdev
->dev
, "failed to allocate memory.\n");
204 platform_set_drvdata(pdev
, ts_dev
);
206 input_dev
= input_allocate_device();
208 dev_err(&pdev
->dev
, "failed to allocate input device.\n");
213 ts_dev
->irq
= platform_get_irq(pdev
, 0);
214 if (ts_dev
->irq
< 0) {
215 dev_err(&pdev
->dev
, "no irq ID is designated.\n");
220 if (!request_mem_region(res
->start
, resource_size(res
),
221 "atmel tsadcc regs")) {
222 dev_err(&pdev
->dev
, "resources is unavailable.\n");
227 tsc_base
= ioremap(res
->start
, resource_size(res
));
229 dev_err(&pdev
->dev
, "failed to map registers.\n");
231 goto err_release_mem
;
234 err
= request_irq(ts_dev
->irq
, atmel_tsadcc_interrupt
, 0,
235 pdev
->dev
.driver
->name
, ts_dev
);
237 dev_err(&pdev
->dev
, "failed to allocate irq.\n");
241 ts_dev
->clk
= clk_get(&pdev
->dev
, "tsc_clk");
242 if (IS_ERR(ts_dev
->clk
)) {
243 dev_err(&pdev
->dev
, "failed to get ts_clk\n");
244 err
= PTR_ERR(ts_dev
->clk
);
248 ts_dev
->input
= input_dev
;
249 ts_dev
->bufferedmeasure
= 0;
251 snprintf(ts_dev
->phys
, sizeof(ts_dev
->phys
),
252 "%s/input0", dev_name(&pdev
->dev
));
254 input_dev
->name
= "atmel touch screen controller";
255 input_dev
->phys
= ts_dev
->phys
;
256 input_dev
->dev
.parent
= &pdev
->dev
;
258 __set_bit(EV_ABS
, input_dev
->evbit
);
259 input_set_abs_params(input_dev
, ABS_X
, 0, 0x3FF, 0, 0);
260 input_set_abs_params(input_dev
, ABS_Y
, 0, 0x3FF, 0, 0);
262 input_set_capability(input_dev
, EV_KEY
, BTN_TOUCH
);
264 /* clk_enable() always returns 0, no need to check it */
265 clk_enable(ts_dev
->clk
);
267 prsc
= clk_get_rate(ts_dev
->clk
);
268 dev_info(&pdev
->dev
, "Master clock is set at: %d Hz\n", prsc
);
270 if (!pdata
->adc_clock
)
271 pdata
->adc_clock
= ADC_DEFAULT_CLOCK
;
273 prsc
= (prsc
/ (2 * pdata
->adc_clock
)) - 1;
275 /* saturate if this value is too high */
276 if (cpu_is_at91sam9rl()) {
277 if (prsc
> PRESCALER_VAL(ATMEL_TSADCC_PRESCAL
))
278 prsc
= PRESCALER_VAL(ATMEL_TSADCC_PRESCAL
);
280 if (prsc
> PRESCALER_VAL(ATMEL_TSADCC_EPRESCAL
))
281 prsc
= PRESCALER_VAL(ATMEL_TSADCC_EPRESCAL
);
284 dev_info(&pdev
->dev
, "Prescaler is set at: %d\n", prsc
);
286 reg
= ATMEL_TSADCC_TSAMOD_TS_ONLY_MODE
|
287 ((0x00 << 5) & ATMEL_TSADCC_SLEEP
) | /* Normal Mode */
288 ((0x01 << 6) & ATMEL_TSADCC_PENDET
) | /* Enable Pen Detect */
290 ((0x26 << 16) & ATMEL_TSADCC_STARTUP
) |
291 ((pdata
->pendet_debounce
<< 28) & ATMEL_TSADCC_PENDBC
);
293 atmel_tsadcc_write(ATMEL_TSADCC_CR
, ATMEL_TSADCC_SWRST
);
294 atmel_tsadcc_write(ATMEL_TSADCC_MR
, reg
);
295 atmel_tsadcc_write(ATMEL_TSADCC_TRGR
, ATMEL_TSADCC_TRGMOD_NONE
);
296 atmel_tsadcc_write(ATMEL_TSADCC_TSR
,
297 (pdata
->ts_sample_hold_time
<< 24) & ATMEL_TSADCC_TSSHTIM
);
299 atmel_tsadcc_read(ATMEL_TSADCC_SR
);
300 atmel_tsadcc_write(ATMEL_TSADCC_IER
, ATMEL_TSADCC_PENCNT
);
302 /* All went ok, so register to the input system */
303 err
= input_register_device(input_dev
);
310 clk_disable(ts_dev
->clk
);
311 clk_put(ts_dev
->clk
);
313 free_irq(ts_dev
->irq
, ts_dev
);
317 release_mem_region(res
->start
, resource_size(res
));
319 input_free_device(input_dev
);
325 static int atmel_tsadcc_remove(struct platform_device
*pdev
)
327 struct atmel_tsadcc
*ts_dev
= platform_get_drvdata(pdev
);
328 struct resource
*res
;
330 free_irq(ts_dev
->irq
, ts_dev
);
332 input_unregister_device(ts_dev
->input
);
334 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
336 release_mem_region(res
->start
, resource_size(res
));
338 clk_disable(ts_dev
->clk
);
339 clk_put(ts_dev
->clk
);
346 static struct platform_driver atmel_tsadcc_driver
= {
347 .probe
= atmel_tsadcc_probe
,
348 .remove
= atmel_tsadcc_remove
,
350 .name
= "atmel_tsadcc",
353 module_platform_driver(atmel_tsadcc_driver
);
355 MODULE_LICENSE("GPL");
356 MODULE_DESCRIPTION("Atmel TouchScreen Driver");
357 MODULE_AUTHOR("Dan Liang <dan.liang@atmel.com>");