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/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>
26 /* Register definitions based on AT91SAM9RL64 preliminary draft datasheet */
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 */
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 */
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 */
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 */
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 */
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 */
74 #define ATMEL_TSADCC_LCDR 0x20 /* Last Converted Data register */
75 #define ATMEL_TSADCC_DATA (0x3ff << 0) /* Channel data */
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 */
87 #define ADC_CLOCK 1000000
90 struct input_dev
*input
;
94 unsigned int prev_absx
;
95 unsigned int prev_absy
;
96 unsigned char bufferedmeasure
;
99 static void __iomem
*tsc_base
;
101 #define atmel_tsadcc_read(reg) __raw_readl(tsc_base + (reg))
102 #define atmel_tsadcc_write(reg, val) __raw_writel((val), tsc_base + (reg))
104 static irqreturn_t
atmel_tsadcc_interrupt(int irq
, void *dev
)
106 struct atmel_tsadcc
*ts_dev
= (struct atmel_tsadcc
*)dev
;
107 struct input_dev
*input_dev
= ts_dev
->input
;
112 status
= atmel_tsadcc_read(ATMEL_TSADCC_SR
);
113 status
&= atmel_tsadcc_read(ATMEL_TSADCC_IMR
);
115 if (status
& ATMEL_TSADCC_NOCNT
) {
117 reg
= atmel_tsadcc_read(ATMEL_TSADCC_MR
) | ATMEL_TSADCC_PENDBC
;
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
);
125 input_report_key(input_dev
, BTN_TOUCH
, 0);
126 ts_dev
->bufferedmeasure
= 0;
127 input_sync(input_dev
);
129 } else if (status
& ATMEL_TSADCC_PENCNT
) {
131 reg
= atmel_tsadcc_read(ATMEL_TSADCC_MR
);
132 reg
&= ~ATMEL_TSADCC_PENDBC
;
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));
141 } else if (status
& ATMEL_TSADCC_EOC(3)) {
142 /* Conversion finished */
144 if (ts_dev
->bufferedmeasure
) {
145 /* Last measurement is always discarded, since it can
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
);
153 ts_dev
->bufferedmeasure
= 1;
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
);
159 ts_dev
->prev_absy
= atmel_tsadcc_read(ATMEL_TSADCC_CDR1
) << 10;
160 ts_dev
->prev_absy
/= atmel_tsadcc_read(ATMEL_TSADCC_CDR0
);
167 * The functions for inserting/removing us as a module.
170 static int __devinit
atmel_tsadcc_probe(struct platform_device
*pdev
)
172 struct atmel_tsadcc
*ts_dev
;
173 struct input_dev
*input_dev
;
174 struct resource
*res
;
179 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
181 dev_err(&pdev
->dev
, "no mmio resource defined.\n");
185 /* Allocate memory for device */
186 ts_dev
= kzalloc(sizeof(struct atmel_tsadcc
), GFP_KERNEL
);
188 dev_err(&pdev
->dev
, "failed to allocate memory.\n");
191 platform_set_drvdata(pdev
, ts_dev
);
193 input_dev
= input_allocate_device();
195 dev_err(&pdev
->dev
, "failed to allocate input device.\n");
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");
207 if (!request_mem_region(res
->start
, resource_size(res
),
208 "atmel tsadcc regs")) {
209 dev_err(&pdev
->dev
, "resources is unavailable.\n");
214 tsc_base
= ioremap(res
->start
, resource_size(res
));
216 dev_err(&pdev
->dev
, "failed to map registers.\n");
218 goto err_release_mem
;
221 err
= request_irq(ts_dev
->irq
, atmel_tsadcc_interrupt
, IRQF_DISABLED
,
222 pdev
->dev
.driver
->name
, ts_dev
);
224 dev_err(&pdev
->dev
, "failed to allocate irq.\n");
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
);
235 ts_dev
->input
= input_dev
;
236 ts_dev
->bufferedmeasure
= 0;
238 snprintf(ts_dev
->phys
, sizeof(ts_dev
->phys
),
239 "%s/input0", dev_name(&pdev
->dev
));
241 input_dev
->name
= "atmel touch screen controller";
242 input_dev
->phys
= ts_dev
->phys
;
243 input_dev
->dev
.parent
= &pdev
->dev
;
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
);
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);
251 /* clk_enable() always returns 0, no need to check it */
252 clk_enable(ts_dev
->clk
);
254 prsc
= clk_get_rate(ts_dev
->clk
);
255 dev_info(&pdev
->dev
, "Master clock is set at: %d Hz\n", prsc
);
257 prsc
= prsc
/ ADC_CLOCK
/ 2 - 1;
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 */
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
);
271 atmel_tsadcc_read(ATMEL_TSADCC_SR
);
272 atmel_tsadcc_write(ATMEL_TSADCC_IER
, ATMEL_TSADCC_PENCNT
);
274 /* All went ok, so register to the input system */
275 err
= input_register_device(input_dev
);
282 clk_disable(ts_dev
->clk
);
283 clk_put(ts_dev
->clk
);
285 free_irq(ts_dev
->irq
, ts_dev
);
289 release_mem_region(res
->start
, resource_size(res
));
291 input_free_device(ts_dev
->input
);
297 static int __devexit
atmel_tsadcc_remove(struct platform_device
*pdev
)
299 struct atmel_tsadcc
*ts_dev
= dev_get_drvdata(&pdev
->dev
);
300 struct resource
*res
;
302 free_irq(ts_dev
->irq
, ts_dev
);
304 input_unregister_device(ts_dev
->input
);
306 res
= platform_get_resource(pdev
, IORESOURCE_MEM
, 0);
308 release_mem_region(res
->start
, resource_size(res
));
310 clk_disable(ts_dev
->clk
);
311 clk_put(ts_dev
->clk
);
318 static struct platform_driver atmel_tsadcc_driver
= {
319 .probe
= atmel_tsadcc_probe
,
320 .remove
= __devexit_p(atmel_tsadcc_remove
),
322 .name
= "atmel_tsadcc",
326 static int __init
atmel_tsadcc_init(void)
328 return platform_driver_register(&atmel_tsadcc_driver
);
331 static void __exit
atmel_tsadcc_exit(void)
333 platform_driver_unregister(&atmel_tsadcc_driver
);
336 module_init(atmel_tsadcc_init
);
337 module_exit(atmel_tsadcc_exit
);
340 MODULE_LICENSE("GPL");
341 MODULE_DESCRIPTION("Atmel TouchScreen Driver");
342 MODULE_AUTHOR("Dan Liang <dan.liang@atmel.com>");