2 * Freescale i.MX28 LRADC driver
4 * Copyright (c) 2012 DENX Software Engineering, GmbH.
5 * Marek Vasut <marex@denx.de>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
18 #include <linux/err.h>
19 #include <linux/interrupt.h>
20 #include <linux/device.h>
21 #include <linux/kernel.h>
22 #include <linux/slab.h>
24 #include <linux/of_device.h>
25 #include <linux/sysfs.h>
26 #include <linux/list.h>
28 #include <linux/module.h>
29 #include <linux/platform_device.h>
30 #include <linux/spinlock.h>
31 #include <linux/wait.h>
32 #include <linux/sched.h>
33 #include <linux/stmp_device.h>
34 #include <linux/bitops.h>
35 #include <linux/completion.h>
36 #include <linux/delay.h>
37 #include <linux/input.h>
38 #include <linux/clk.h>
40 #include <linux/iio/iio.h>
41 #include <linux/iio/sysfs.h>
42 #include <linux/iio/buffer.h>
43 #include <linux/iio/trigger.h>
44 #include <linux/iio/trigger_consumer.h>
45 #include <linux/iio/triggered_buffer.h>
47 #define DRIVER_NAME "mxs-lradc"
49 #define LRADC_MAX_DELAY_CHANS 4
50 #define LRADC_MAX_MAPPED_CHANS 8
51 #define LRADC_MAX_TOTAL_CHANS 16
53 #define LRADC_DELAY_TIMER_HZ 2000
56 * Make this runtime configurable if necessary. Currently, if the buffered mode
57 * is enabled, the LRADC takes LRADC_DELAY_TIMER_LOOP samples of data before
58 * triggering IRQ. The sampling happens every (LRADC_DELAY_TIMER_PER / 2000)
59 * seconds. The result is that the samples arrive every 500mS.
61 #define LRADC_DELAY_TIMER_PER 200
62 #define LRADC_DELAY_TIMER_LOOP 5
65 * Once the pen touches the touchscreen, the touchscreen switches from
66 * IRQ-driven mode to polling mode to prevent interrupt storm. The polling
67 * is realized by worker thread, which is called every 20 or so milliseconds.
68 * This gives the touchscreen enough fluence and does not strain the system
71 #define LRADC_TS_SAMPLE_DELAY_MS 5
74 * The LRADC reads the following amount of samples from each touchscreen
75 * channel and the driver then computes avarage of these.
77 #define LRADC_TS_SAMPLE_AMOUNT 4
84 static const char * const mx23_lradc_irq_names[] = {
85 "mxs-lradc-touchscreen",
96 static const char * const mx28_lradc_irq_names[] = {
97 "mxs-lradc-touchscreen",
100 "mxs-lradc-channel0",
101 "mxs-lradc-channel1",
102 "mxs-lradc-channel2",
103 "mxs-lradc-channel3",
104 "mxs-lradc-channel4",
105 "mxs-lradc-channel5",
106 "mxs-lradc-channel6",
107 "mxs-lradc-channel7",
112 struct mxs_lradc_of_config {
114 const char * const *irq_name;
115 const uint32_t *vref_mv;
118 #define VREF_MV_BASE 1850
120 static const uint32_t mx23_vref_mv[LRADC_MAX_TOTAL_CHANS] = {
121 VREF_MV_BASE, /* CH0 */
122 VREF_MV_BASE, /* CH1 */
123 VREF_MV_BASE, /* CH2 */
124 VREF_MV_BASE, /* CH3 */
125 VREF_MV_BASE, /* CH4 */
126 VREF_MV_BASE, /* CH5 */
127 VREF_MV_BASE * 2, /* CH6 VDDIO */
128 VREF_MV_BASE * 4, /* CH7 VBATT */
129 VREF_MV_BASE, /* CH8 Temp sense 0 */
130 VREF_MV_BASE, /* CH9 Temp sense 1 */
131 VREF_MV_BASE, /* CH10 */
132 VREF_MV_BASE, /* CH11 */
133 VREF_MV_BASE, /* CH12 USB_DP */
134 VREF_MV_BASE, /* CH13 USB_DN */
135 VREF_MV_BASE, /* CH14 VBG */
136 VREF_MV_BASE * 4, /* CH15 VDD5V */
139 static const uint32_t mx28_vref_mv[LRADC_MAX_TOTAL_CHANS] = {
140 VREF_MV_BASE, /* CH0 */
141 VREF_MV_BASE, /* CH1 */
142 VREF_MV_BASE, /* CH2 */
143 VREF_MV_BASE, /* CH3 */
144 VREF_MV_BASE, /* CH4 */
145 VREF_MV_BASE, /* CH5 */
146 VREF_MV_BASE, /* CH6 */
147 VREF_MV_BASE * 4, /* CH7 VBATT */
148 VREF_MV_BASE, /* CH8 Temp sense 0 */
149 VREF_MV_BASE, /* CH9 Temp sense 1 */
150 VREF_MV_BASE * 2, /* CH10 VDDIO */
151 VREF_MV_BASE, /* CH11 VTH */
152 VREF_MV_BASE * 2, /* CH12 VDDA */
153 VREF_MV_BASE, /* CH13 VDDD */
154 VREF_MV_BASE, /* CH14 VBG */
155 VREF_MV_BASE * 4, /* CH15 VDD5V */
158 static const struct mxs_lradc_of_config mxs_lradc_of_config[] = {
160 .irq_count = ARRAY_SIZE(mx23_lradc_irq_names),
161 .irq_name = mx23_lradc_irq_names,
162 .vref_mv = mx23_vref_mv,
165 .irq_count = ARRAY_SIZE(mx28_lradc_irq_names),
166 .irq_name = mx28_lradc_irq_names,
167 .vref_mv = mx28_vref_mv,
172 MXS_LRADC_TOUCHSCREEN_NONE = 0,
173 MXS_LRADC_TOUCHSCREEN_4WIRE,
174 MXS_LRADC_TOUCHSCREEN_5WIRE,
178 * Touchscreen handling
180 enum lradc_ts_plate {
184 LRADC_SAMPLE_PRESSURE,
188 enum mxs_lradc_divbytwo {
189 MXS_LRADC_DIV_DISABLED = 0,
190 MXS_LRADC_DIV_ENABLED,
193 struct mxs_lradc_scale {
194 unsigned int integer;
206 struct iio_trigger *trig;
210 struct completion completion;
212 const uint32_t *vref_mv;
213 struct mxs_lradc_scale scale_avail[LRADC_MAX_TOTAL_CHANS][2];
214 unsigned long is_divided;
217 * Touchscreen LRADC channels receives a private slot in the CTRL4
218 * register, the slot #7. Therefore only 7 slots instead of 8 in the
219 * CTRL4 register can be mapped to LRADC channels when using the
222 * Furthermore, certain LRADC channels are shared between touchscreen
223 * and/or touch-buttons and generic LRADC block. Therefore when using
224 * either of these, these channels are not available for the regular
225 * sampling. The shared channels are as follows:
227 * CH0 -- Touch button #0
228 * CH1 -- Touch button #1
229 * CH2 -- Touch screen XPUL
230 * CH3 -- Touch screen YPLL
231 * CH4 -- Touch screen XNUL
232 * CH5 -- Touch screen YNLR
233 * CH6 -- Touch screen WIPER (5-wire only)
235 * The bitfields below represents which parts of the LRADC block are
236 * switched into special mode of operation. These channels can not
237 * be sampled as regular LRADC channels. The driver will refuse any
238 * attempt to sample these channels.
240 #define CHAN_MASK_TOUCHBUTTON (0x3 << 0)
241 #define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 2)
242 #define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 2)
243 enum mxs_lradc_ts use_touchscreen;
244 bool use_touchbutton;
246 struct input_dev *ts_input;
248 enum mxs_lradc_id soc;
249 enum lradc_ts_plate cur_plate; /* statemachine */
253 unsigned ts_pressure;
255 /* handle touchscreen's physical behaviour */
256 /* samples per coordinate */
257 unsigned over_sample_cnt;
258 /* time clocks between samples */
259 unsigned over_sample_delay;
260 /* time in clocks to wait after the plates where switched */
261 unsigned settling_delay;
264 #define LRADC_CTRL0 0x00
265 # define LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE (1 << 23)
266 # define LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE (1 << 22)
267 # define LRADC_CTRL0_MX28_YNNSW /* YM */ (1 << 21)
268 # define LRADC_CTRL0_MX28_YPNSW /* YP */ (1 << 20)
269 # define LRADC_CTRL0_MX28_YPPSW /* YP */ (1 << 19)
270 # define LRADC_CTRL0_MX28_XNNSW /* XM */ (1 << 18)
271 # define LRADC_CTRL0_MX28_XNPSW /* XM */ (1 << 17)
272 # define LRADC_CTRL0_MX28_XPPSW /* XP */ (1 << 16)
274 # define LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE (1 << 20)
275 # define LRADC_CTRL0_MX23_YM (1 << 19)
276 # define LRADC_CTRL0_MX23_XM (1 << 18)
277 # define LRADC_CTRL0_MX23_YP (1 << 17)
278 # define LRADC_CTRL0_MX23_XP (1 << 16)
280 # define LRADC_CTRL0_MX28_PLATE_MASK \
281 (LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE | \
282 LRADC_CTRL0_MX28_YNNSW | LRADC_CTRL0_MX28_YPNSW | \
283 LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW | \
284 LRADC_CTRL0_MX28_XNPSW | LRADC_CTRL0_MX28_XPPSW)
286 # define LRADC_CTRL0_MX23_PLATE_MASK \
287 (LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE | \
288 LRADC_CTRL0_MX23_YM | LRADC_CTRL0_MX23_XM | \
289 LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_XP)
291 #define LRADC_CTRL1 0x10
292 #define LRADC_CTRL1_TOUCH_DETECT_IRQ_EN (1 << 24)
293 #define LRADC_CTRL1_LRADC_IRQ_EN(n) (1 << ((n) + 16))
294 #define LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK (0x1fff << 16)
295 #define LRADC_CTRL1_MX23_LRADC_IRQ_EN_MASK (0x01ff << 16)
296 #define LRADC_CTRL1_LRADC_IRQ_EN_OFFSET 16
297 #define LRADC_CTRL1_TOUCH_DETECT_IRQ (1 << 8)
298 #define LRADC_CTRL1_LRADC_IRQ(n) (1 << (n))
299 #define LRADC_CTRL1_MX28_LRADC_IRQ_MASK 0x1fff
300 #define LRADC_CTRL1_MX23_LRADC_IRQ_MASK 0x01ff
301 #define LRADC_CTRL1_LRADC_IRQ_OFFSET 0
303 #define LRADC_CTRL2 0x20
304 #define LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET 24
305 #define LRADC_CTRL2_TEMPSENSE_PWD (1 << 15)
307 #define LRADC_STATUS 0x40
308 #define LRADC_STATUS_TOUCH_DETECT_RAW (1 << 0)
310 #define LRADC_CH(n) (0x50 + (0x10 * (n)))
311 #define LRADC_CH_ACCUMULATE (1 << 29)
312 #define LRADC_CH_NUM_SAMPLES_MASK (0x1f << 24)
313 #define LRADC_CH_NUM_SAMPLES_OFFSET 24
314 #define LRADC_CH_NUM_SAMPLES(x) \
315 ((x) << LRADC_CH_NUM_SAMPLES_OFFSET)
316 #define LRADC_CH_VALUE_MASK 0x3ffff
317 #define LRADC_CH_VALUE_OFFSET 0
319 #define LRADC_DELAY(n) (0xd0 + (0x10 * (n)))
320 #define LRADC_DELAY_TRIGGER_LRADCS_MASK (0xff << 24)
321 #define LRADC_DELAY_TRIGGER_LRADCS_OFFSET 24
322 #define LRADC_DELAY_TRIGGER(x) \
323 (((x) << LRADC_DELAY_TRIGGER_LRADCS_OFFSET) & \
324 LRADC_DELAY_TRIGGER_LRADCS_MASK)
325 #define LRADC_DELAY_KICK (1 << 20)
326 #define LRADC_DELAY_TRIGGER_DELAYS_MASK (0xf << 16)
327 #define LRADC_DELAY_TRIGGER_DELAYS_OFFSET 16
328 #define LRADC_DELAY_TRIGGER_DELAYS(x) \
329 (((x) << LRADC_DELAY_TRIGGER_DELAYS_OFFSET) & \
330 LRADC_DELAY_TRIGGER_DELAYS_MASK)
331 #define LRADC_DELAY_LOOP_COUNT_MASK (0x1f << 11)
332 #define LRADC_DELAY_LOOP_COUNT_OFFSET 11
333 #define LRADC_DELAY_LOOP(x) \
334 (((x) << LRADC_DELAY_LOOP_COUNT_OFFSET) & \
335 LRADC_DELAY_LOOP_COUNT_MASK)
336 #define LRADC_DELAY_DELAY_MASK 0x7ff
337 #define LRADC_DELAY_DELAY_OFFSET 0
338 #define LRADC_DELAY_DELAY(x) \
339 (((x) << LRADC_DELAY_DELAY_OFFSET) & \
340 LRADC_DELAY_DELAY_MASK)
342 #define LRADC_CTRL4 0x140
343 #define LRADC_CTRL4_LRADCSELECT_MASK(n) (0xf << ((n) * 4))
344 #define LRADC_CTRL4_LRADCSELECT_OFFSET(n) ((n) * 4)
346 #define LRADC_RESOLUTION 12
347 #define LRADC_SINGLE_SAMPLE_MASK ((1 << LRADC_RESOLUTION) - 1)
349 static void mxs_lradc_reg_set(struct mxs_lradc *lradc, u32 val, u32 reg)
351 writel(val, lradc->base + reg + STMP_OFFSET_REG_SET);
354 static void mxs_lradc_reg_clear(struct mxs_lradc *lradc, u32 val, u32 reg)
356 writel(val, lradc->base + reg + STMP_OFFSET_REG_CLR);
359 static void mxs_lradc_reg_wrt(struct mxs_lradc *lradc, u32 val, u32 reg)
361 writel(val, lradc->base + reg);
364 static u32 mxs_lradc_plate_mask(struct mxs_lradc *lradc)
366 if (lradc->soc == IMX23_LRADC)
367 return LRADC_CTRL0_MX23_PLATE_MASK;
368 return LRADC_CTRL0_MX28_PLATE_MASK;
371 static u32 mxs_lradc_irq_en_mask(struct mxs_lradc *lradc)
373 if (lradc->soc == IMX23_LRADC)
374 return LRADC_CTRL1_MX23_LRADC_IRQ_EN_MASK;
375 return LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK;
378 static u32 mxs_lradc_irq_mask(struct mxs_lradc *lradc)
380 if (lradc->soc == IMX23_LRADC)
381 return LRADC_CTRL1_MX23_LRADC_IRQ_MASK;
382 return LRADC_CTRL1_MX28_LRADC_IRQ_MASK;
385 static u32 mxs_lradc_touch_detect_bit(struct mxs_lradc *lradc)
387 if (lradc->soc == IMX23_LRADC)
388 return LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE;
389 return LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE;
392 static u32 mxs_lradc_drive_x_plate(struct mxs_lradc *lradc)
394 if (lradc->soc == IMX23_LRADC)
395 return LRADC_CTRL0_MX23_XP | LRADC_CTRL0_MX23_XM;
396 return LRADC_CTRL0_MX28_XPPSW | LRADC_CTRL0_MX28_XNNSW;
399 static u32 mxs_lradc_drive_y_plate(struct mxs_lradc *lradc)
401 if (lradc->soc == IMX23_LRADC)
402 return LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_YM;
403 return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_YNNSW;
406 static u32 mxs_lradc_drive_pressure(struct mxs_lradc *lradc)
408 if (lradc->soc == IMX23_LRADC)
409 return LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_XM;
410 return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW;
413 static bool mxs_lradc_check_touch_event(struct mxs_lradc *lradc)
415 return !!(readl(lradc->base + LRADC_STATUS) &
416 LRADC_STATUS_TOUCH_DETECT_RAW);
419 static void mxs_lradc_setup_ts_channel(struct mxs_lradc *lradc, unsigned ch)
422 * prepare for oversampling conversion
424 * from the datasheet:
425 * "The ACCUMULATE bit in the appropriate channel register
426 * HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
427 * otherwise, the IRQs will not fire."
429 mxs_lradc_reg_wrt(lradc, LRADC_CH_ACCUMULATE |
430 LRADC_CH_NUM_SAMPLES(lradc->over_sample_cnt - 1),
433 /* from the datasheet:
434 * "Software must clear this register in preparation for a
435 * multi-cycle accumulation.
437 mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch));
439 /* prepare the delay/loop unit according to the oversampling count */
440 mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(1 << ch) |
441 LRADC_DELAY_TRIGGER_DELAYS(0) |
442 LRADC_DELAY_LOOP(lradc->over_sample_cnt - 1) |
443 LRADC_DELAY_DELAY(lradc->over_sample_delay - 1),
446 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(2) |
447 LRADC_CTRL1_LRADC_IRQ(3) | LRADC_CTRL1_LRADC_IRQ(4) |
448 LRADC_CTRL1_LRADC_IRQ(5), LRADC_CTRL1);
450 /* wake us again, when the complete conversion is done */
451 mxs_lradc_reg_set(lradc, LRADC_CTRL1_LRADC_IRQ_EN(ch), LRADC_CTRL1);
453 * after changing the touchscreen plates setting
454 * the signals need some initial time to settle. Start the
455 * SoC's delay unit and start the conversion later
458 mxs_lradc_reg_wrt(lradc,
459 LRADC_DELAY_TRIGGER(0) | /* don't trigger ADC */
460 LRADC_DELAY_TRIGGER_DELAYS(1 << 3) | /* trigger DELAY unit#3 */
462 LRADC_DELAY_DELAY(lradc->settling_delay),
467 * Pressure detection is special:
468 * We want to do both required measurements for the pressure detection in
469 * one turn. Use the hardware features to chain both conversions and let the
470 * hardware report one interrupt if both conversions are done
472 static void mxs_lradc_setup_ts_pressure(struct mxs_lradc *lradc, unsigned ch1,
478 * prepare for oversampling conversion
480 * from the datasheet:
481 * "The ACCUMULATE bit in the appropriate channel register
482 * HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
483 * otherwise, the IRQs will not fire."
485 reg = LRADC_CH_ACCUMULATE |
486 LRADC_CH_NUM_SAMPLES(lradc->over_sample_cnt - 1);
487 mxs_lradc_reg_wrt(lradc, reg, LRADC_CH(ch1));
488 mxs_lradc_reg_wrt(lradc, reg, LRADC_CH(ch2));
490 /* from the datasheet:
491 * "Software must clear this register in preparation for a
492 * multi-cycle accumulation.
494 mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch1));
495 mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch2));
497 /* prepare the delay/loop unit according to the oversampling count */
498 mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(1 << ch1) |
499 LRADC_DELAY_TRIGGER(1 << ch2) | /* start both channels */
500 LRADC_DELAY_TRIGGER_DELAYS(0) |
501 LRADC_DELAY_LOOP(lradc->over_sample_cnt - 1) |
502 LRADC_DELAY_DELAY(lradc->over_sample_delay - 1),
505 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(2) |
506 LRADC_CTRL1_LRADC_IRQ(3) | LRADC_CTRL1_LRADC_IRQ(4) |
507 LRADC_CTRL1_LRADC_IRQ(5), LRADC_CTRL1);
509 /* wake us again, when the conversions are done */
510 mxs_lradc_reg_set(lradc, LRADC_CTRL1_LRADC_IRQ_EN(ch2), LRADC_CTRL1);
512 * after changing the touchscreen plates setting
513 * the signals need some initial time to settle. Start the
514 * SoC's delay unit and start the conversion later
517 mxs_lradc_reg_wrt(lradc,
518 LRADC_DELAY_TRIGGER(0) | /* don't trigger ADC */
519 LRADC_DELAY_TRIGGER_DELAYS(1 << 3) | /* trigger DELAY unit#3 */
521 LRADC_DELAY_DELAY(lradc->settling_delay), LRADC_DELAY(2));
524 static unsigned mxs_lradc_read_raw_channel(struct mxs_lradc *lradc,
528 unsigned num_samples, val;
530 reg = readl(lradc->base + LRADC_CH(channel));
531 if (reg & LRADC_CH_ACCUMULATE)
532 num_samples = lradc->over_sample_cnt;
536 val = (reg & LRADC_CH_VALUE_MASK) >> LRADC_CH_VALUE_OFFSET;
537 return val / num_samples;
540 static unsigned mxs_lradc_read_ts_pressure(struct mxs_lradc *lradc,
541 unsigned ch1, unsigned ch2)
544 unsigned pressure, m1, m2;
546 mask = LRADC_CTRL1_LRADC_IRQ(ch1) | LRADC_CTRL1_LRADC_IRQ(ch2);
547 reg = readl(lradc->base + LRADC_CTRL1) & mask;
549 while (reg != mask) {
550 reg = readl(lradc->base + LRADC_CTRL1) & mask;
551 dev_dbg(lradc->dev, "One channel is still busy: %X\n", reg);
554 m1 = mxs_lradc_read_raw_channel(lradc, ch1);
555 m2 = mxs_lradc_read_raw_channel(lradc, ch2);
558 dev_warn(lradc->dev, "Cannot calculate pressure\n");
559 return 1 << (LRADC_RESOLUTION - 1);
562 /* simply scale the value from 0 ... max ADC resolution */
564 pressure *= (1 << LRADC_RESOLUTION);
567 dev_dbg(lradc->dev, "Pressure = %u\n", pressure);
576 static int mxs_lradc_read_ts_channel(struct mxs_lradc *lradc)
581 reg = readl(lradc->base + LRADC_CTRL1);
583 /* only channels 3 to 5 are of interest here */
584 if (reg & LRADC_CTRL1_LRADC_IRQ(TS_CH_YP)) {
585 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(TS_CH_YP) |
586 LRADC_CTRL1_LRADC_IRQ(TS_CH_YP), LRADC_CTRL1);
587 val = mxs_lradc_read_raw_channel(lradc, TS_CH_YP);
588 } else if (reg & LRADC_CTRL1_LRADC_IRQ(TS_CH_XM)) {
589 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(TS_CH_XM) |
590 LRADC_CTRL1_LRADC_IRQ(TS_CH_XM), LRADC_CTRL1);
591 val = mxs_lradc_read_raw_channel(lradc, TS_CH_XM);
592 } else if (reg & LRADC_CTRL1_LRADC_IRQ(TS_CH_YM)) {
593 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(TS_CH_YM) |
594 LRADC_CTRL1_LRADC_IRQ(TS_CH_YM), LRADC_CTRL1);
595 val = mxs_lradc_read_raw_channel(lradc, TS_CH_YM);
600 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(2));
601 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(3));
607 * YP(open)--+-------------+
610 * YM(-)--+-------------+ |
615 * "weak+" means 200k Ohm VDDIO
618 static void mxs_lradc_setup_touch_detection(struct mxs_lradc *lradc)
621 * In order to detect a touch event the 'touch detect enable' bit
623 * - a weak pullup to the X+ connector
624 * - a strong ground at the Y- connector
626 mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
627 mxs_lradc_reg_set(lradc, mxs_lradc_touch_detect_bit(lradc),
632 * YP(meas)--+-------------+
635 * YM(open)--+-------------+ |
640 * (+) means here 1.85 V
643 static void mxs_lradc_prepare_x_pos(struct mxs_lradc *lradc)
645 mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
646 mxs_lradc_reg_set(lradc, mxs_lradc_drive_x_plate(lradc), LRADC_CTRL0);
648 lradc->cur_plate = LRADC_SAMPLE_X;
649 mxs_lradc_setup_ts_channel(lradc, TS_CH_YP);
653 * YP(+)--+-------------+
656 * YM(-)--+-------------+ |
661 * (+) means here 1.85 V
664 static void mxs_lradc_prepare_y_pos(struct mxs_lradc *lradc)
666 mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
667 mxs_lradc_reg_set(lradc, mxs_lradc_drive_y_plate(lradc), LRADC_CTRL0);
669 lradc->cur_plate = LRADC_SAMPLE_Y;
670 mxs_lradc_setup_ts_channel(lradc, TS_CH_XM);
674 * YP(+)--+-------------+
677 * YM(meas)--+-------------+ |
682 * (+) means here 1.85 V
685 static void mxs_lradc_prepare_pressure(struct mxs_lradc *lradc)
687 mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
688 mxs_lradc_reg_set(lradc, mxs_lradc_drive_pressure(lradc), LRADC_CTRL0);
690 lradc->cur_plate = LRADC_SAMPLE_PRESSURE;
691 mxs_lradc_setup_ts_pressure(lradc, TS_CH_XP, TS_CH_YM);
694 static void mxs_lradc_enable_touch_detection(struct mxs_lradc *lradc)
696 mxs_lradc_setup_touch_detection(lradc);
698 lradc->cur_plate = LRADC_TOUCH;
699 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ |
700 LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
701 mxs_lradc_reg_set(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
704 static void mxs_lradc_report_ts_event(struct mxs_lradc *lradc)
706 input_report_abs(lradc->ts_input, ABS_X, lradc->ts_x_pos);
707 input_report_abs(lradc->ts_input, ABS_Y, lradc->ts_y_pos);
708 input_report_abs(lradc->ts_input, ABS_PRESSURE, lradc->ts_pressure);
709 input_report_key(lradc->ts_input, BTN_TOUCH, 1);
710 input_sync(lradc->ts_input);
713 static void mxs_lradc_complete_touch_event(struct mxs_lradc *lradc)
715 mxs_lradc_setup_touch_detection(lradc);
716 lradc->cur_plate = LRADC_SAMPLE_VALID;
718 * start a dummy conversion to burn time to settle the signals
719 * note: we are not interested in the conversion's value
721 mxs_lradc_reg_wrt(lradc, 0, LRADC_CH(5));
722 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(5), LRADC_CTRL1);
723 mxs_lradc_reg_set(lradc, LRADC_CTRL1_LRADC_IRQ_EN(5), LRADC_CTRL1);
724 mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(1 << 5) |
725 LRADC_DELAY_KICK | LRADC_DELAY_DELAY(10), /* waste 5 ms */
730 * in order to avoid false measurements, report only samples where
731 * the surface is still touched after the position measurement
733 static void mxs_lradc_finish_touch_event(struct mxs_lradc *lradc, bool valid)
735 /* if it is still touched, report the sample */
736 if (valid && mxs_lradc_check_touch_event(lradc)) {
737 lradc->ts_valid = true;
738 mxs_lradc_report_ts_event(lradc);
741 /* if it is even still touched, continue with the next measurement */
742 if (mxs_lradc_check_touch_event(lradc)) {
743 mxs_lradc_prepare_y_pos(lradc);
747 if (lradc->ts_valid) {
748 /* signal the release */
749 lradc->ts_valid = false;
750 input_report_key(lradc->ts_input, BTN_TOUCH, 0);
751 input_sync(lradc->ts_input);
754 /* if it is released, wait for the next touch via IRQ */
755 lradc->cur_plate = LRADC_TOUCH;
756 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ, LRADC_CTRL1);
757 mxs_lradc_reg_set(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
760 /* touchscreen's state machine */
761 static void mxs_lradc_handle_touch(struct mxs_lradc *lradc)
765 switch (lradc->cur_plate) {
768 * start with the Y-pos, because it uses nearly the same plate
769 * settings like the touch detection
771 if (mxs_lradc_check_touch_event(lradc)) {
772 mxs_lradc_reg_clear(lradc,
773 LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
775 mxs_lradc_prepare_y_pos(lradc);
777 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ,
782 val = mxs_lradc_read_ts_channel(lradc);
784 mxs_lradc_enable_touch_detection(lradc); /* re-start */
787 lradc->ts_y_pos = val;
788 mxs_lradc_prepare_x_pos(lradc);
792 val = mxs_lradc_read_ts_channel(lradc);
794 mxs_lradc_enable_touch_detection(lradc); /* re-start */
797 lradc->ts_x_pos = val;
798 mxs_lradc_prepare_pressure(lradc);
801 case LRADC_SAMPLE_PRESSURE:
803 mxs_lradc_read_ts_pressure(lradc, TS_CH_XP, TS_CH_YM);
804 mxs_lradc_complete_touch_event(lradc);
807 case LRADC_SAMPLE_VALID:
808 val = mxs_lradc_read_ts_channel(lradc); /* ignore the value */
809 mxs_lradc_finish_touch_event(lradc, 1);
817 static int mxs_lradc_read_single(struct iio_dev *iio_dev, int chan, int *val)
819 struct mxs_lradc *lradc = iio_priv(iio_dev);
823 * See if there is no buffered operation in progess. If there is, simply
824 * bail out. This can be improved to support both buffered and raw IO at
825 * the same time, yet the code becomes horribly complicated. Therefore I
826 * applied KISS principle here.
828 ret = mutex_trylock(&lradc->lock);
832 reinit_completion(&lradc->completion);
835 * No buffered operation in progress, map the channel and trigger it.
836 * Virtual channel 0 is always used here as the others are always not
837 * used if doing raw sampling.
839 if (lradc->soc == IMX28_LRADC)
840 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK,
842 mxs_lradc_reg_clear(lradc, 0xff, LRADC_CTRL0);
844 /* Enable / disable the divider per requirement */
845 if (test_bit(chan, &lradc->is_divided))
846 mxs_lradc_reg_set(lradc, 1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
849 mxs_lradc_reg_clear(lradc,
850 1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET, LRADC_CTRL2);
852 /* Clean the slot's previous content, then set new one. */
853 mxs_lradc_reg_clear(lradc, LRADC_CTRL4_LRADCSELECT_MASK(0),
855 mxs_lradc_reg_set(lradc, chan, LRADC_CTRL4);
857 mxs_lradc_reg_wrt(lradc, 0, LRADC_CH(0));
859 /* Enable the IRQ and start sampling the channel. */
860 mxs_lradc_reg_set(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0), LRADC_CTRL1);
861 mxs_lradc_reg_set(lradc, 1 << 0, LRADC_CTRL0);
863 /* Wait for completion on the channel, 1 second max. */
864 ret = wait_for_completion_killable_timeout(&lradc->completion, HZ);
871 *val = readl(lradc->base + LRADC_CH(0)) & LRADC_CH_VALUE_MASK;
875 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0), LRADC_CTRL1);
877 mutex_unlock(&lradc->lock);
882 static int mxs_lradc_read_temp(struct iio_dev *iio_dev, int *val)
886 ret = mxs_lradc_read_single(iio_dev, 8, &min);
887 if (ret != IIO_VAL_INT)
890 ret = mxs_lradc_read_single(iio_dev, 9, &max);
891 if (ret != IIO_VAL_INT)
899 static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
900 const struct iio_chan_spec *chan,
901 int *val, int *val2, long m)
903 struct mxs_lradc *lradc = iio_priv(iio_dev);
906 case IIO_CHAN_INFO_RAW:
907 if (chan->type == IIO_TEMP)
908 return mxs_lradc_read_temp(iio_dev, val);
910 return mxs_lradc_read_single(iio_dev, chan->channel, val);
912 case IIO_CHAN_INFO_SCALE:
913 if (chan->type == IIO_TEMP) {
914 /* From the datasheet, we have to multiply by 1.012 and
919 return IIO_VAL_INT_PLUS_MICRO;
922 *val = lradc->vref_mv[chan->channel];
923 *val2 = chan->scan_type.realbits -
924 test_bit(chan->channel, &lradc->is_divided);
925 return IIO_VAL_FRACTIONAL_LOG2;
927 case IIO_CHAN_INFO_OFFSET:
928 if (chan->type == IIO_TEMP) {
929 /* The calculated value from the ADC is in Kelvin, we
930 * want Celsius for hwmon so the offset is
936 return IIO_VAL_INT_PLUS_MICRO;
948 static int mxs_lradc_write_raw(struct iio_dev *iio_dev,
949 const struct iio_chan_spec *chan,
950 int val, int val2, long m)
952 struct mxs_lradc *lradc = iio_priv(iio_dev);
953 struct mxs_lradc_scale *scale_avail =
954 lradc->scale_avail[chan->channel];
957 ret = mutex_trylock(&lradc->lock);
962 case IIO_CHAN_INFO_SCALE:
964 if (val == scale_avail[MXS_LRADC_DIV_DISABLED].integer &&
965 val2 == scale_avail[MXS_LRADC_DIV_DISABLED].nano) {
966 /* divider by two disabled */
967 clear_bit(chan->channel, &lradc->is_divided);
969 } else if (val == scale_avail[MXS_LRADC_DIV_ENABLED].integer &&
970 val2 == scale_avail[MXS_LRADC_DIV_ENABLED].nano) {
971 /* divider by two enabled */
972 set_bit(chan->channel, &lradc->is_divided);
982 mutex_unlock(&lradc->lock);
987 static int mxs_lradc_write_raw_get_fmt(struct iio_dev *iio_dev,
988 const struct iio_chan_spec *chan,
991 return IIO_VAL_INT_PLUS_NANO;
994 static ssize_t mxs_lradc_show_scale_available_ch(struct device *dev,
995 struct device_attribute *attr,
999 struct iio_dev *iio = dev_to_iio_dev(dev);
1000 struct mxs_lradc *lradc = iio_priv(iio);
1003 for (i = 0; i < ARRAY_SIZE(lradc->scale_avail[ch]); i++)
1004 len += sprintf(buf + len, "%d.%09u ",
1005 lradc->scale_avail[ch][i].integer,
1006 lradc->scale_avail[ch][i].nano);
1008 len += sprintf(buf + len, "\n");
1013 static ssize_t mxs_lradc_show_scale_available(struct device *dev,
1014 struct device_attribute *attr,
1017 struct iio_dev_attr *iio_attr = to_iio_dev_attr(attr);
1019 return mxs_lradc_show_scale_available_ch(dev, attr, buf,
1023 #define SHOW_SCALE_AVAILABLE_ATTR(ch) \
1024 static IIO_DEVICE_ATTR(in_voltage##ch##_scale_available, S_IRUGO, \
1025 mxs_lradc_show_scale_available, NULL, ch)
1027 SHOW_SCALE_AVAILABLE_ATTR(0);
1028 SHOW_SCALE_AVAILABLE_ATTR(1);
1029 SHOW_SCALE_AVAILABLE_ATTR(2);
1030 SHOW_SCALE_AVAILABLE_ATTR(3);
1031 SHOW_SCALE_AVAILABLE_ATTR(4);
1032 SHOW_SCALE_AVAILABLE_ATTR(5);
1033 SHOW_SCALE_AVAILABLE_ATTR(6);
1034 SHOW_SCALE_AVAILABLE_ATTR(7);
1035 SHOW_SCALE_AVAILABLE_ATTR(10);
1036 SHOW_SCALE_AVAILABLE_ATTR(11);
1037 SHOW_SCALE_AVAILABLE_ATTR(12);
1038 SHOW_SCALE_AVAILABLE_ATTR(13);
1039 SHOW_SCALE_AVAILABLE_ATTR(14);
1040 SHOW_SCALE_AVAILABLE_ATTR(15);
1042 static struct attribute *mxs_lradc_attributes[] = {
1043 &iio_dev_attr_in_voltage0_scale_available.dev_attr.attr,
1044 &iio_dev_attr_in_voltage1_scale_available.dev_attr.attr,
1045 &iio_dev_attr_in_voltage2_scale_available.dev_attr.attr,
1046 &iio_dev_attr_in_voltage3_scale_available.dev_attr.attr,
1047 &iio_dev_attr_in_voltage4_scale_available.dev_attr.attr,
1048 &iio_dev_attr_in_voltage5_scale_available.dev_attr.attr,
1049 &iio_dev_attr_in_voltage6_scale_available.dev_attr.attr,
1050 &iio_dev_attr_in_voltage7_scale_available.dev_attr.attr,
1051 &iio_dev_attr_in_voltage10_scale_available.dev_attr.attr,
1052 &iio_dev_attr_in_voltage11_scale_available.dev_attr.attr,
1053 &iio_dev_attr_in_voltage12_scale_available.dev_attr.attr,
1054 &iio_dev_attr_in_voltage13_scale_available.dev_attr.attr,
1055 &iio_dev_attr_in_voltage14_scale_available.dev_attr.attr,
1056 &iio_dev_attr_in_voltage15_scale_available.dev_attr.attr,
1060 static const struct attribute_group mxs_lradc_attribute_group = {
1061 .attrs = mxs_lradc_attributes,
1064 static const struct iio_info mxs_lradc_iio_info = {
1065 .driver_module = THIS_MODULE,
1066 .read_raw = mxs_lradc_read_raw,
1067 .write_raw = mxs_lradc_write_raw,
1068 .write_raw_get_fmt = mxs_lradc_write_raw_get_fmt,
1069 .attrs = &mxs_lradc_attribute_group,
1072 static int mxs_lradc_ts_open(struct input_dev *dev)
1074 struct mxs_lradc *lradc = input_get_drvdata(dev);
1076 /* Enable the touch-detect circuitry. */
1077 mxs_lradc_enable_touch_detection(lradc);
1082 static void mxs_lradc_disable_ts(struct mxs_lradc *lradc)
1084 /* stop all interrupts from firing */
1085 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN |
1086 LRADC_CTRL1_LRADC_IRQ_EN(2) | LRADC_CTRL1_LRADC_IRQ_EN(3) |
1087 LRADC_CTRL1_LRADC_IRQ_EN(4) | LRADC_CTRL1_LRADC_IRQ_EN(5),
1090 /* Power-down touchscreen touch-detect circuitry. */
1091 mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
1094 static void mxs_lradc_ts_close(struct input_dev *dev)
1096 struct mxs_lradc *lradc = input_get_drvdata(dev);
1098 mxs_lradc_disable_ts(lradc);
1101 static int mxs_lradc_ts_register(struct mxs_lradc *lradc)
1103 struct input_dev *input;
1104 struct device *dev = lradc->dev;
1107 if (!lradc->use_touchscreen)
1110 input = input_allocate_device();
1114 input->name = DRIVER_NAME;
1115 input->id.bustype = BUS_HOST;
1116 input->dev.parent = dev;
1117 input->open = mxs_lradc_ts_open;
1118 input->close = mxs_lradc_ts_close;
1120 __set_bit(EV_ABS, input->evbit);
1121 __set_bit(EV_KEY, input->evbit);
1122 __set_bit(BTN_TOUCH, input->keybit);
1123 input_set_abs_params(input, ABS_X, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0);
1124 input_set_abs_params(input, ABS_Y, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0);
1125 input_set_abs_params(input, ABS_PRESSURE, 0, LRADC_SINGLE_SAMPLE_MASK,
1128 lradc->ts_input = input;
1129 input_set_drvdata(input, lradc);
1130 ret = input_register_device(input);
1132 input_free_device(lradc->ts_input);
1137 static void mxs_lradc_ts_unregister(struct mxs_lradc *lradc)
1139 if (!lradc->use_touchscreen)
1142 mxs_lradc_disable_ts(lradc);
1143 input_unregister_device(lradc->ts_input);
1149 static irqreturn_t mxs_lradc_handle_irq(int irq, void *data)
1151 struct iio_dev *iio = data;
1152 struct mxs_lradc *lradc = iio_priv(iio);
1153 unsigned long reg = readl(lradc->base + LRADC_CTRL1);
1154 const uint32_t ts_irq_mask =
1155 LRADC_CTRL1_TOUCH_DETECT_IRQ |
1156 LRADC_CTRL1_LRADC_IRQ(2) |
1157 LRADC_CTRL1_LRADC_IRQ(3) |
1158 LRADC_CTRL1_LRADC_IRQ(4) |
1159 LRADC_CTRL1_LRADC_IRQ(5);
1161 if (!(reg & mxs_lradc_irq_mask(lradc)))
1164 if (lradc->use_touchscreen && (reg & ts_irq_mask))
1165 mxs_lradc_handle_touch(lradc);
1167 if (iio_buffer_enabled(iio))
1168 iio_trigger_poll(iio->trig);
1169 else if (reg & LRADC_CTRL1_LRADC_IRQ(0))
1170 complete(&lradc->completion);
1172 mxs_lradc_reg_clear(lradc, reg & mxs_lradc_irq_mask(lradc),
1181 static irqreturn_t mxs_lradc_trigger_handler(int irq, void *p)
1183 struct iio_poll_func *pf = p;
1184 struct iio_dev *iio = pf->indio_dev;
1185 struct mxs_lradc *lradc = iio_priv(iio);
1186 const uint32_t chan_value = LRADC_CH_ACCUMULATE |
1187 ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET);
1188 unsigned int i, j = 0;
1190 for_each_set_bit(i, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) {
1191 lradc->buffer[j] = readl(lradc->base + LRADC_CH(j));
1192 mxs_lradc_reg_wrt(lradc, chan_value, LRADC_CH(j));
1193 lradc->buffer[j] &= LRADC_CH_VALUE_MASK;
1194 lradc->buffer[j] /= LRADC_DELAY_TIMER_LOOP;
1198 iio_push_to_buffers_with_timestamp(iio, lradc->buffer, pf->timestamp);
1200 iio_trigger_notify_done(iio->trig);
1205 static int mxs_lradc_configure_trigger(struct iio_trigger *trig, bool state)
1207 struct iio_dev *iio = iio_trigger_get_drvdata(trig);
1208 struct mxs_lradc *lradc = iio_priv(iio);
1209 const uint32_t st = state ? STMP_OFFSET_REG_SET : STMP_OFFSET_REG_CLR;
1211 mxs_lradc_reg_wrt(lradc, LRADC_DELAY_KICK, LRADC_DELAY(0) + st);
1216 static const struct iio_trigger_ops mxs_lradc_trigger_ops = {
1217 .owner = THIS_MODULE,
1218 .set_trigger_state = &mxs_lradc_configure_trigger,
1221 static int mxs_lradc_trigger_init(struct iio_dev *iio)
1224 struct iio_trigger *trig;
1225 struct mxs_lradc *lradc = iio_priv(iio);
1227 trig = iio_trigger_alloc("%s-dev%i", iio->name, iio->id);
1231 trig->dev.parent = lradc->dev;
1232 iio_trigger_set_drvdata(trig, iio);
1233 trig->ops = &mxs_lradc_trigger_ops;
1235 ret = iio_trigger_register(trig);
1237 iio_trigger_free(trig);
1246 static void mxs_lradc_trigger_remove(struct iio_dev *iio)
1248 struct mxs_lradc *lradc = iio_priv(iio);
1250 iio_trigger_unregister(lradc->trig);
1251 iio_trigger_free(lradc->trig);
1254 static int mxs_lradc_buffer_preenable(struct iio_dev *iio)
1256 struct mxs_lradc *lradc = iio_priv(iio);
1257 int ret = 0, chan, ofs = 0;
1258 unsigned long enable = 0;
1259 uint32_t ctrl4_set = 0;
1260 uint32_t ctrl4_clr = 0;
1261 uint32_t ctrl1_irq = 0;
1262 const uint32_t chan_value = LRADC_CH_ACCUMULATE |
1263 ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET);
1264 const int len = bitmap_weight(iio->active_scan_mask,
1265 LRADC_MAX_TOTAL_CHANS);
1271 * Lock the driver so raw access can not be done during buffered
1272 * operation. This simplifies the code a lot.
1274 ret = mutex_trylock(&lradc->lock);
1278 lradc->buffer = kmalloc_array(len, sizeof(*lradc->buffer), GFP_KERNEL);
1279 if (!lradc->buffer) {
1284 if (lradc->soc == IMX28_LRADC)
1285 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK,
1287 mxs_lradc_reg_clear(lradc, 0xff, LRADC_CTRL0);
1289 for_each_set_bit(chan, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) {
1290 ctrl4_set |= chan << LRADC_CTRL4_LRADCSELECT_OFFSET(ofs);
1291 ctrl4_clr |= LRADC_CTRL4_LRADCSELECT_MASK(ofs);
1292 ctrl1_irq |= LRADC_CTRL1_LRADC_IRQ_EN(ofs);
1293 mxs_lradc_reg_wrt(lradc, chan_value, LRADC_CH(ofs));
1294 bitmap_set(&enable, ofs, 1);
1298 mxs_lradc_reg_clear(lradc, LRADC_DELAY_TRIGGER_LRADCS_MASK |
1299 LRADC_DELAY_KICK, LRADC_DELAY(0));
1300 mxs_lradc_reg_clear(lradc, ctrl4_clr, LRADC_CTRL4);
1301 mxs_lradc_reg_set(lradc, ctrl4_set, LRADC_CTRL4);
1302 mxs_lradc_reg_set(lradc, ctrl1_irq, LRADC_CTRL1);
1303 mxs_lradc_reg_set(lradc, enable << LRADC_DELAY_TRIGGER_LRADCS_OFFSET,
1309 mutex_unlock(&lradc->lock);
1313 static int mxs_lradc_buffer_postdisable(struct iio_dev *iio)
1315 struct mxs_lradc *lradc = iio_priv(iio);
1317 mxs_lradc_reg_clear(lradc, LRADC_DELAY_TRIGGER_LRADCS_MASK |
1318 LRADC_DELAY_KICK, LRADC_DELAY(0));
1320 mxs_lradc_reg_clear(lradc, 0xff, LRADC_CTRL0);
1321 if (lradc->soc == IMX28_LRADC)
1322 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK,
1325 kfree(lradc->buffer);
1326 mutex_unlock(&lradc->lock);
1331 static bool mxs_lradc_validate_scan_mask(struct iio_dev *iio,
1332 const unsigned long *mask)
1334 struct mxs_lradc *lradc = iio_priv(iio);
1335 const int map_chans = bitmap_weight(mask, LRADC_MAX_TOTAL_CHANS);
1337 unsigned long rsvd_mask = 0;
1339 if (lradc->use_touchbutton)
1340 rsvd_mask |= CHAN_MASK_TOUCHBUTTON;
1341 if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_4WIRE)
1342 rsvd_mask |= CHAN_MASK_TOUCHSCREEN_4WIRE;
1343 if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE)
1344 rsvd_mask |= CHAN_MASK_TOUCHSCREEN_5WIRE;
1346 if (lradc->use_touchbutton)
1348 if (lradc->use_touchscreen)
1351 /* Test for attempts to map channels with special mode of operation. */
1352 if (bitmap_intersects(mask, &rsvd_mask, LRADC_MAX_TOTAL_CHANS))
1355 /* Test for attempts to map more channels then available slots. */
1356 if (map_chans + rsvd_chans > LRADC_MAX_MAPPED_CHANS)
1362 static const struct iio_buffer_setup_ops mxs_lradc_buffer_ops = {
1363 .preenable = &mxs_lradc_buffer_preenable,
1364 .postenable = &iio_triggered_buffer_postenable,
1365 .predisable = &iio_triggered_buffer_predisable,
1366 .postdisable = &mxs_lradc_buffer_postdisable,
1367 .validate_scan_mask = &mxs_lradc_validate_scan_mask,
1371 * Driver initialization
1374 #define MXS_ADC_CHAN(idx, chan_type) { \
1375 .type = (chan_type), \
1377 .scan_index = (idx), \
1378 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
1379 BIT(IIO_CHAN_INFO_SCALE), \
1384 .realbits = LRADC_RESOLUTION, \
1385 .storagebits = 32, \
1389 static const struct iio_chan_spec mxs_lradc_chan_spec[] = {
1390 MXS_ADC_CHAN(0, IIO_VOLTAGE),
1391 MXS_ADC_CHAN(1, IIO_VOLTAGE),
1392 MXS_ADC_CHAN(2, IIO_VOLTAGE),
1393 MXS_ADC_CHAN(3, IIO_VOLTAGE),
1394 MXS_ADC_CHAN(4, IIO_VOLTAGE),
1395 MXS_ADC_CHAN(5, IIO_VOLTAGE),
1396 MXS_ADC_CHAN(6, IIO_VOLTAGE),
1397 MXS_ADC_CHAN(7, IIO_VOLTAGE), /* VBATT */
1398 /* Combined Temperature sensors */
1403 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
1404 BIT(IIO_CHAN_INFO_OFFSET) |
1405 BIT(IIO_CHAN_INFO_SCALE),
1407 .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
1409 MXS_ADC_CHAN(10, IIO_VOLTAGE), /* VDDIO */
1410 MXS_ADC_CHAN(11, IIO_VOLTAGE), /* VTH */
1411 MXS_ADC_CHAN(12, IIO_VOLTAGE), /* VDDA */
1412 MXS_ADC_CHAN(13, IIO_VOLTAGE), /* VDDD */
1413 MXS_ADC_CHAN(14, IIO_VOLTAGE), /* VBG */
1414 MXS_ADC_CHAN(15, IIO_VOLTAGE), /* VDD5V */
1417 static int mxs_lradc_hw_init(struct mxs_lradc *lradc)
1419 /* The ADC always uses DELAY CHANNEL 0. */
1420 const uint32_t adc_cfg =
1421 (1 << (LRADC_DELAY_TRIGGER_DELAYS_OFFSET + 0)) |
1422 (LRADC_DELAY_TIMER_PER << LRADC_DELAY_DELAY_OFFSET);
1424 int ret = stmp_reset_block(lradc->base);
1429 /* Configure DELAY CHANNEL 0 for generic ADC sampling. */
1430 mxs_lradc_reg_wrt(lradc, adc_cfg, LRADC_DELAY(0));
1432 /* Disable remaining DELAY CHANNELs */
1433 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(1));
1434 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(2));
1435 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(3));
1437 /* Configure the touchscreen type */
1438 if (lradc->soc == IMX28_LRADC) {
1439 mxs_lradc_reg_clear(lradc, LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
1442 if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE)
1443 mxs_lradc_reg_set(lradc, LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
1447 /* Start internal temperature sensing. */
1448 mxs_lradc_reg_wrt(lradc, 0, LRADC_CTRL2);
1453 static void mxs_lradc_hw_stop(struct mxs_lradc *lradc)
1457 mxs_lradc_reg_clear(lradc, mxs_lradc_irq_en_mask(lradc), LRADC_CTRL1);
1459 for (i = 0; i < LRADC_MAX_DELAY_CHANS; i++)
1460 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(i));
1463 static const struct of_device_id mxs_lradc_dt_ids[] = {
1464 { .compatible = "fsl,imx23-lradc", .data = (void *)IMX23_LRADC, },
1465 { .compatible = "fsl,imx28-lradc", .data = (void *)IMX28_LRADC, },
1468 MODULE_DEVICE_TABLE(of, mxs_lradc_dt_ids);
1470 static int mxs_lradc_probe_touchscreen(struct mxs_lradc *lradc,
1471 struct device_node *lradc_node)
1474 u32 ts_wires = 0, adapt;
1476 ret = of_property_read_u32(lradc_node, "fsl,lradc-touchscreen-wires",
1479 return -ENODEV; /* touchscreen feature disabled */
1483 lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_4WIRE;
1486 if (lradc->soc == IMX28_LRADC) {
1487 lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_5WIRE;
1490 /* fall through an error message for i.MX23 */
1493 "Unsupported number of touchscreen wires (%d)\n",
1498 lradc->over_sample_cnt = 4;
1499 ret = of_property_read_u32(lradc_node, "fsl,ave-ctrl", &adapt);
1501 lradc->over_sample_cnt = adapt;
1503 lradc->over_sample_delay = 2;
1504 ret = of_property_read_u32(lradc_node, "fsl,ave-delay", &adapt);
1506 lradc->over_sample_delay = adapt;
1508 lradc->settling_delay = 10;
1509 ret = of_property_read_u32(lradc_node, "fsl,settling", &adapt);
1511 lradc->settling_delay = adapt;
1516 static int mxs_lradc_probe(struct platform_device *pdev)
1518 const struct of_device_id *of_id =
1519 of_match_device(mxs_lradc_dt_ids, &pdev->dev);
1520 const struct mxs_lradc_of_config *of_cfg =
1521 &mxs_lradc_of_config[(enum mxs_lradc_id)of_id->data];
1522 struct device *dev = &pdev->dev;
1523 struct device_node *node = dev->of_node;
1524 struct mxs_lradc *lradc;
1525 struct iio_dev *iio;
1526 struct resource *iores;
1527 int ret = 0, touch_ret;
1531 /* Allocate the IIO device. */
1532 iio = devm_iio_device_alloc(dev, sizeof(*lradc));
1534 dev_err(dev, "Failed to allocate IIO device\n");
1538 lradc = iio_priv(iio);
1539 lradc->soc = (enum mxs_lradc_id)of_id->data;
1541 /* Grab the memory area */
1542 iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1543 lradc->dev = &pdev->dev;
1544 lradc->base = devm_ioremap_resource(dev, iores);
1545 if (IS_ERR(lradc->base))
1546 return PTR_ERR(lradc->base);
1548 lradc->clk = devm_clk_get(&pdev->dev, NULL);
1549 if (IS_ERR(lradc->clk)) {
1550 dev_err(dev, "Failed to get the delay unit clock\n");
1551 return PTR_ERR(lradc->clk);
1553 ret = clk_prepare_enable(lradc->clk);
1555 dev_err(dev, "Failed to enable the delay unit clock\n");
1559 touch_ret = mxs_lradc_probe_touchscreen(lradc, node);
1561 /* Grab all IRQ sources */
1562 for (i = 0; i < of_cfg->irq_count; i++) {
1563 lradc->irq[i] = platform_get_irq(pdev, i);
1564 if (lradc->irq[i] < 0) {
1565 ret = lradc->irq[i];
1569 ret = devm_request_irq(dev, lradc->irq[i],
1570 mxs_lradc_handle_irq, 0,
1571 of_cfg->irq_name[i], iio);
1576 lradc->vref_mv = of_cfg->vref_mv;
1578 platform_set_drvdata(pdev, iio);
1580 init_completion(&lradc->completion);
1581 mutex_init(&lradc->lock);
1583 iio->name = pdev->name;
1584 iio->dev.parent = &pdev->dev;
1585 iio->info = &mxs_lradc_iio_info;
1586 iio->modes = INDIO_DIRECT_MODE;
1587 iio->channels = mxs_lradc_chan_spec;
1588 iio->num_channels = ARRAY_SIZE(mxs_lradc_chan_spec);
1589 iio->masklength = LRADC_MAX_TOTAL_CHANS;
1591 ret = iio_triggered_buffer_setup(iio, &iio_pollfunc_store_time,
1592 &mxs_lradc_trigger_handler,
1593 &mxs_lradc_buffer_ops);
1597 ret = mxs_lradc_trigger_init(iio);
1601 /* Populate available ADC input ranges */
1602 for (i = 0; i < LRADC_MAX_TOTAL_CHANS; i++) {
1603 for (s = 0; s < ARRAY_SIZE(lradc->scale_avail[i]); s++) {
1605 * [s=0] = optional divider by two disabled (default)
1606 * [s=1] = optional divider by two enabled
1608 * The scale is calculated by doing:
1609 * Vref >> (realbits - s)
1610 * which multiplies by two on the second component
1613 scale_uv = ((u64)lradc->vref_mv[i] * 100000000) >>
1614 (LRADC_RESOLUTION - s);
1615 lradc->scale_avail[i][s].nano =
1616 do_div(scale_uv, 100000000) * 10;
1617 lradc->scale_avail[i][s].integer = scale_uv;
1621 /* Configure the hardware. */
1622 ret = mxs_lradc_hw_init(lradc);
1626 /* Register the touchscreen input device. */
1627 if (touch_ret == 0) {
1628 ret = mxs_lradc_ts_register(lradc);
1630 goto err_ts_register;
1633 /* Register IIO device. */
1634 ret = iio_device_register(iio);
1636 dev_err(dev, "Failed to register IIO device\n");
1643 mxs_lradc_ts_unregister(lradc);
1645 mxs_lradc_hw_stop(lradc);
1647 mxs_lradc_trigger_remove(iio);
1649 iio_triggered_buffer_cleanup(iio);
1651 clk_disable_unprepare(lradc->clk);
1655 static int mxs_lradc_remove(struct platform_device *pdev)
1657 struct iio_dev *iio = platform_get_drvdata(pdev);
1658 struct mxs_lradc *lradc = iio_priv(iio);
1660 iio_device_unregister(iio);
1661 mxs_lradc_ts_unregister(lradc);
1662 mxs_lradc_hw_stop(lradc);
1663 mxs_lradc_trigger_remove(iio);
1664 iio_triggered_buffer_cleanup(iio);
1666 clk_disable_unprepare(lradc->clk);
1670 static struct platform_driver mxs_lradc_driver = {
1672 .name = DRIVER_NAME,
1673 .of_match_table = mxs_lradc_dt_ids,
1675 .probe = mxs_lradc_probe,
1676 .remove = mxs_lradc_remove,
1679 module_platform_driver(mxs_lradc_driver);
1681 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
1682 MODULE_DESCRIPTION("Freescale i.MX28 LRADC driver");
1683 MODULE_LICENSE("GPL v2");
1684 MODULE_ALIAS("platform:" DRIVER_NAME);