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 * When the touchscreen is enabled, we give it two private virtual
218 * channels: #6 and #7. This means that only 6 virtual channels (instead
219 * of 8) will be available for buffered capture.
221 #define TOUCHSCREEN_VCHANNEL1 7
222 #define TOUCHSCREEN_VCHANNEL2 6
223 #define BUFFER_VCHANS_LIMITED 0x3f
224 #define BUFFER_VCHANS_ALL 0xff
228 * Furthermore, certain LRADC channels are shared between touchscreen
229 * and/or touch-buttons and generic LRADC block. Therefore when using
230 * either of these, these channels are not available for the regular
231 * sampling. The shared channels are as follows:
233 * CH0 -- Touch button #0
234 * CH1 -- Touch button #1
235 * CH2 -- Touch screen XPUL
236 * CH3 -- Touch screen YPLL
237 * CH4 -- Touch screen XNUL
238 * CH5 -- Touch screen YNLR
239 * CH6 -- Touch screen WIPER (5-wire only)
241 * The bitfields below represents which parts of the LRADC block are
242 * switched into special mode of operation. These channels can not
243 * be sampled as regular LRADC channels. The driver will refuse any
244 * attempt to sample these channels.
246 #define CHAN_MASK_TOUCHBUTTON (0x3 << 0)
247 #define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 2)
248 #define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 2)
249 enum mxs_lradc_ts use_touchscreen;
250 bool use_touchbutton;
252 struct input_dev *ts_input;
254 enum mxs_lradc_id soc;
255 enum lradc_ts_plate cur_plate; /* statemachine */
259 unsigned ts_pressure;
261 /* handle touchscreen's physical behaviour */
262 /* samples per coordinate */
263 unsigned over_sample_cnt;
264 /* time clocks between samples */
265 unsigned over_sample_delay;
266 /* time in clocks to wait after the plates where switched */
267 unsigned settling_delay;
270 #define LRADC_CTRL0 0x00
271 # define LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE (1 << 23)
272 # define LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE (1 << 22)
273 # define LRADC_CTRL0_MX28_YNNSW /* YM */ (1 << 21)
274 # define LRADC_CTRL0_MX28_YPNSW /* YP */ (1 << 20)
275 # define LRADC_CTRL0_MX28_YPPSW /* YP */ (1 << 19)
276 # define LRADC_CTRL0_MX28_XNNSW /* XM */ (1 << 18)
277 # define LRADC_CTRL0_MX28_XNPSW /* XM */ (1 << 17)
278 # define LRADC_CTRL0_MX28_XPPSW /* XP */ (1 << 16)
280 # define LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE (1 << 20)
281 # define LRADC_CTRL0_MX23_YM (1 << 19)
282 # define LRADC_CTRL0_MX23_XM (1 << 18)
283 # define LRADC_CTRL0_MX23_YP (1 << 17)
284 # define LRADC_CTRL0_MX23_XP (1 << 16)
286 # define LRADC_CTRL0_MX28_PLATE_MASK \
287 (LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE | \
288 LRADC_CTRL0_MX28_YNNSW | LRADC_CTRL0_MX28_YPNSW | \
289 LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW | \
290 LRADC_CTRL0_MX28_XNPSW | LRADC_CTRL0_MX28_XPPSW)
292 # define LRADC_CTRL0_MX23_PLATE_MASK \
293 (LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE | \
294 LRADC_CTRL0_MX23_YM | LRADC_CTRL0_MX23_XM | \
295 LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_XP)
297 #define LRADC_CTRL1 0x10
298 #define LRADC_CTRL1_TOUCH_DETECT_IRQ_EN (1 << 24)
299 #define LRADC_CTRL1_LRADC_IRQ_EN(n) (1 << ((n) + 16))
300 #define LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK (0x1fff << 16)
301 #define LRADC_CTRL1_MX23_LRADC_IRQ_EN_MASK (0x01ff << 16)
302 #define LRADC_CTRL1_LRADC_IRQ_EN_OFFSET 16
303 #define LRADC_CTRL1_TOUCH_DETECT_IRQ (1 << 8)
304 #define LRADC_CTRL1_LRADC_IRQ(n) (1 << (n))
305 #define LRADC_CTRL1_MX28_LRADC_IRQ_MASK 0x1fff
306 #define LRADC_CTRL1_MX23_LRADC_IRQ_MASK 0x01ff
307 #define LRADC_CTRL1_LRADC_IRQ_OFFSET 0
309 #define LRADC_CTRL2 0x20
310 #define LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET 24
311 #define LRADC_CTRL2_TEMPSENSE_PWD (1 << 15)
313 #define LRADC_STATUS 0x40
314 #define LRADC_STATUS_TOUCH_DETECT_RAW (1 << 0)
316 #define LRADC_CH(n) (0x50 + (0x10 * (n)))
317 #define LRADC_CH_ACCUMULATE (1 << 29)
318 #define LRADC_CH_NUM_SAMPLES_MASK (0x1f << 24)
319 #define LRADC_CH_NUM_SAMPLES_OFFSET 24
320 #define LRADC_CH_NUM_SAMPLES(x) \
321 ((x) << LRADC_CH_NUM_SAMPLES_OFFSET)
322 #define LRADC_CH_VALUE_MASK 0x3ffff
323 #define LRADC_CH_VALUE_OFFSET 0
325 #define LRADC_DELAY(n) (0xd0 + (0x10 * (n)))
326 #define LRADC_DELAY_TRIGGER_LRADCS_MASK (0xff << 24)
327 #define LRADC_DELAY_TRIGGER_LRADCS_OFFSET 24
328 #define LRADC_DELAY_TRIGGER(x) \
329 (((x) << LRADC_DELAY_TRIGGER_LRADCS_OFFSET) & \
330 LRADC_DELAY_TRIGGER_LRADCS_MASK)
331 #define LRADC_DELAY_KICK (1 << 20)
332 #define LRADC_DELAY_TRIGGER_DELAYS_MASK (0xf << 16)
333 #define LRADC_DELAY_TRIGGER_DELAYS_OFFSET 16
334 #define LRADC_DELAY_TRIGGER_DELAYS(x) \
335 (((x) << LRADC_DELAY_TRIGGER_DELAYS_OFFSET) & \
336 LRADC_DELAY_TRIGGER_DELAYS_MASK)
337 #define LRADC_DELAY_LOOP_COUNT_MASK (0x1f << 11)
338 #define LRADC_DELAY_LOOP_COUNT_OFFSET 11
339 #define LRADC_DELAY_LOOP(x) \
340 (((x) << LRADC_DELAY_LOOP_COUNT_OFFSET) & \
341 LRADC_DELAY_LOOP_COUNT_MASK)
342 #define LRADC_DELAY_DELAY_MASK 0x7ff
343 #define LRADC_DELAY_DELAY_OFFSET 0
344 #define LRADC_DELAY_DELAY(x) \
345 (((x) << LRADC_DELAY_DELAY_OFFSET) & \
346 LRADC_DELAY_DELAY_MASK)
348 #define LRADC_CTRL4 0x140
349 #define LRADC_CTRL4_LRADCSELECT_MASK(n) (0xf << ((n) * 4))
350 #define LRADC_CTRL4_LRADCSELECT_OFFSET(n) ((n) * 4)
351 #define LRADC_CTRL4_LRADCSELECT(n, x) \
352 (((x) << LRADC_CTRL4_LRADCSELECT_OFFSET(n)) & \
353 LRADC_CTRL4_LRADCSELECT_MASK(n))
355 #define LRADC_RESOLUTION 12
356 #define LRADC_SINGLE_SAMPLE_MASK ((1 << LRADC_RESOLUTION) - 1)
358 static void mxs_lradc_reg_set(struct mxs_lradc *lradc, u32 val, u32 reg)
360 writel(val, lradc->base + reg + STMP_OFFSET_REG_SET);
363 static void mxs_lradc_reg_clear(struct mxs_lradc *lradc, u32 val, u32 reg)
365 writel(val, lradc->base + reg + STMP_OFFSET_REG_CLR);
368 static void mxs_lradc_reg_wrt(struct mxs_lradc *lradc, u32 val, u32 reg)
370 writel(val, lradc->base + reg);
373 static u32 mxs_lradc_plate_mask(struct mxs_lradc *lradc)
375 if (lradc->soc == IMX23_LRADC)
376 return LRADC_CTRL0_MX23_PLATE_MASK;
378 return LRADC_CTRL0_MX28_PLATE_MASK;
381 static u32 mxs_lradc_irq_en_mask(struct mxs_lradc *lradc)
383 if (lradc->soc == IMX23_LRADC)
384 return LRADC_CTRL1_MX23_LRADC_IRQ_EN_MASK;
386 return LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK;
389 static u32 mxs_lradc_irq_mask(struct mxs_lradc *lradc)
391 if (lradc->soc == IMX23_LRADC)
392 return LRADC_CTRL1_MX23_LRADC_IRQ_MASK;
394 return LRADC_CTRL1_MX28_LRADC_IRQ_MASK;
397 static u32 mxs_lradc_touch_detect_bit(struct mxs_lradc *lradc)
399 if (lradc->soc == IMX23_LRADC)
400 return LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE;
402 return LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE;
405 static u32 mxs_lradc_drive_x_plate(struct mxs_lradc *lradc)
407 if (lradc->soc == IMX23_LRADC)
408 return LRADC_CTRL0_MX23_XP | LRADC_CTRL0_MX23_XM;
410 return LRADC_CTRL0_MX28_XPPSW | LRADC_CTRL0_MX28_XNNSW;
413 static u32 mxs_lradc_drive_y_plate(struct mxs_lradc *lradc)
415 if (lradc->soc == IMX23_LRADC)
416 return LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_YM;
418 return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_YNNSW;
421 static u32 mxs_lradc_drive_pressure(struct mxs_lradc *lradc)
423 if (lradc->soc == IMX23_LRADC)
424 return LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_XM;
426 return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW;
429 static bool mxs_lradc_check_touch_event(struct mxs_lradc *lradc)
431 return !!(readl(lradc->base + LRADC_STATUS) &
432 LRADC_STATUS_TOUCH_DETECT_RAW);
435 static void mxs_lradc_map_channel(struct mxs_lradc *lradc, unsigned vch,
438 mxs_lradc_reg_clear(lradc, LRADC_CTRL4_LRADCSELECT_MASK(vch),
440 mxs_lradc_reg_set(lradc, LRADC_CTRL4_LRADCSELECT(vch, ch), LRADC_CTRL4);
443 static void mxs_lradc_setup_ts_channel(struct mxs_lradc *lradc, unsigned ch)
446 * prepare for oversampling conversion
448 * from the datasheet:
449 * "The ACCUMULATE bit in the appropriate channel register
450 * HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
451 * otherwise, the IRQs will not fire."
453 mxs_lradc_reg_wrt(lradc, LRADC_CH_ACCUMULATE |
454 LRADC_CH_NUM_SAMPLES(lradc->over_sample_cnt - 1),
457 /* from the datasheet:
458 * "Software must clear this register in preparation for a
459 * multi-cycle accumulation.
461 mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch));
463 /* prepare the delay/loop unit according to the oversampling count */
464 mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(1 << ch) |
465 LRADC_DELAY_TRIGGER_DELAYS(0) |
466 LRADC_DELAY_LOOP(lradc->over_sample_cnt - 1) |
467 LRADC_DELAY_DELAY(lradc->over_sample_delay - 1),
470 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(ch), LRADC_CTRL1);
473 * after changing the touchscreen plates setting
474 * the signals need some initial time to settle. Start the
475 * SoC's delay unit and start the conversion later
478 mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(0) | /* don't trigger ADC */
479 LRADC_DELAY_TRIGGER_DELAYS(1 << 3) | /* trigger DELAY unit#3 */
481 LRADC_DELAY_DELAY(lradc->settling_delay),
486 * Pressure detection is special:
487 * We want to do both required measurements for the pressure detection in
488 * one turn. Use the hardware features to chain both conversions and let the
489 * hardware report one interrupt if both conversions are done
491 static void mxs_lradc_setup_ts_pressure(struct mxs_lradc *lradc, unsigned ch1,
497 * prepare for oversampling conversion
499 * from the datasheet:
500 * "The ACCUMULATE bit in the appropriate channel register
501 * HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
502 * otherwise, the IRQs will not fire."
504 reg = LRADC_CH_ACCUMULATE |
505 LRADC_CH_NUM_SAMPLES(lradc->over_sample_cnt - 1);
506 mxs_lradc_reg_wrt(lradc, reg, LRADC_CH(ch1));
507 mxs_lradc_reg_wrt(lradc, reg, LRADC_CH(ch2));
509 /* from the datasheet:
510 * "Software must clear this register in preparation for a
511 * multi-cycle accumulation.
513 mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch1));
514 mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch2));
516 /* prepare the delay/loop unit according to the oversampling count */
517 mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(1 << ch1) |
518 LRADC_DELAY_TRIGGER(1 << ch2) | /* start both channels */
519 LRADC_DELAY_TRIGGER_DELAYS(0) |
520 LRADC_DELAY_LOOP(lradc->over_sample_cnt - 1) |
521 LRADC_DELAY_DELAY(lradc->over_sample_delay - 1),
524 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(ch2), LRADC_CTRL1);
527 * after changing the touchscreen plates setting
528 * the signals need some initial time to settle. Start the
529 * SoC's delay unit and start the conversion later
532 mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(0) | /* don't trigger ADC */
533 LRADC_DELAY_TRIGGER_DELAYS(1 << 3) | /* trigger DELAY unit#3 */
535 LRADC_DELAY_DELAY(lradc->settling_delay), LRADC_DELAY(2));
538 static unsigned mxs_lradc_read_raw_channel(struct mxs_lradc *lradc,
542 unsigned num_samples, val;
544 reg = readl(lradc->base + LRADC_CH(channel));
545 if (reg & LRADC_CH_ACCUMULATE)
546 num_samples = lradc->over_sample_cnt;
550 val = (reg & LRADC_CH_VALUE_MASK) >> LRADC_CH_VALUE_OFFSET;
551 return val / num_samples;
554 static unsigned mxs_lradc_read_ts_pressure(struct mxs_lradc *lradc,
555 unsigned ch1, unsigned ch2)
558 unsigned pressure, m1, m2;
560 mask = LRADC_CTRL1_LRADC_IRQ(ch1) | LRADC_CTRL1_LRADC_IRQ(ch2);
561 reg = readl(lradc->base + LRADC_CTRL1) & mask;
563 while (reg != mask) {
564 reg = readl(lradc->base + LRADC_CTRL1) & mask;
565 dev_dbg(lradc->dev, "One channel is still busy: %X\n", reg);
568 m1 = mxs_lradc_read_raw_channel(lradc, ch1);
569 m2 = mxs_lradc_read_raw_channel(lradc, ch2);
572 dev_warn(lradc->dev, "Cannot calculate pressure\n");
573 return 1 << (LRADC_RESOLUTION - 1);
576 /* simply scale the value from 0 ... max ADC resolution */
578 pressure *= (1 << LRADC_RESOLUTION);
581 dev_dbg(lradc->dev, "Pressure = %u\n", pressure);
591 * YP(open)--+-------------+
594 * YM(-)--+-------------+ |
599 * "weak+" means 200k Ohm VDDIO
602 static void mxs_lradc_setup_touch_detection(struct mxs_lradc *lradc)
605 * In order to detect a touch event the 'touch detect enable' bit
607 * - a weak pullup to the X+ connector
608 * - a strong ground at the Y- connector
610 mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
611 mxs_lradc_reg_set(lradc, mxs_lradc_touch_detect_bit(lradc),
616 * YP(meas)--+-------------+
619 * YM(open)--+-------------+ |
624 * (+) means here 1.85 V
627 static void mxs_lradc_prepare_x_pos(struct mxs_lradc *lradc)
629 mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
630 mxs_lradc_reg_set(lradc, mxs_lradc_drive_x_plate(lradc), LRADC_CTRL0);
632 lradc->cur_plate = LRADC_SAMPLE_X;
633 mxs_lradc_map_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_YP);
634 mxs_lradc_setup_ts_channel(lradc, TOUCHSCREEN_VCHANNEL1);
638 * YP(+)--+-------------+
641 * YM(-)--+-------------+ |
646 * (+) means here 1.85 V
649 static void mxs_lradc_prepare_y_pos(struct mxs_lradc *lradc)
651 mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
652 mxs_lradc_reg_set(lradc, mxs_lradc_drive_y_plate(lradc), LRADC_CTRL0);
654 lradc->cur_plate = LRADC_SAMPLE_Y;
655 mxs_lradc_map_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_XM);
656 mxs_lradc_setup_ts_channel(lradc, TOUCHSCREEN_VCHANNEL1);
660 * YP(+)--+-------------+
663 * YM(meas)--+-------------+ |
668 * (+) means here 1.85 V
671 static void mxs_lradc_prepare_pressure(struct mxs_lradc *lradc)
673 mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
674 mxs_lradc_reg_set(lradc, mxs_lradc_drive_pressure(lradc), LRADC_CTRL0);
676 lradc->cur_plate = LRADC_SAMPLE_PRESSURE;
677 mxs_lradc_map_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_YM);
678 mxs_lradc_map_channel(lradc, TOUCHSCREEN_VCHANNEL2, TS_CH_XP);
679 mxs_lradc_setup_ts_pressure(lradc, TOUCHSCREEN_VCHANNEL2,
680 TOUCHSCREEN_VCHANNEL1);
683 static void mxs_lradc_enable_touch_detection(struct mxs_lradc *lradc)
685 mxs_lradc_setup_touch_detection(lradc);
687 lradc->cur_plate = LRADC_TOUCH;
688 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ |
689 LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
690 mxs_lradc_reg_set(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
693 static void mxs_lradc_start_touch_event(struct mxs_lradc *lradc)
695 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
697 mxs_lradc_reg_set(lradc,
698 LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1), LRADC_CTRL1);
700 * start with the Y-pos, because it uses nearly the same plate
701 * settings like the touch detection
703 mxs_lradc_prepare_y_pos(lradc);
706 static void mxs_lradc_report_ts_event(struct mxs_lradc *lradc)
708 input_report_abs(lradc->ts_input, ABS_X, lradc->ts_x_pos);
709 input_report_abs(lradc->ts_input, ABS_Y, lradc->ts_y_pos);
710 input_report_abs(lradc->ts_input, ABS_PRESSURE, lradc->ts_pressure);
711 input_report_key(lradc->ts_input, BTN_TOUCH, 1);
712 input_sync(lradc->ts_input);
715 static void mxs_lradc_complete_touch_event(struct mxs_lradc *lradc)
717 mxs_lradc_setup_touch_detection(lradc);
718 lradc->cur_plate = LRADC_SAMPLE_VALID;
720 * start a dummy conversion to burn time to settle the signals
721 * note: we are not interested in the conversion's value
723 mxs_lradc_reg_wrt(lradc, 0, LRADC_CH(TOUCHSCREEN_VCHANNEL1));
724 mxs_lradc_reg_clear(lradc,
725 LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
726 LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2), LRADC_CTRL1);
727 mxs_lradc_reg_wrt(lradc,
728 LRADC_DELAY_TRIGGER(1 << TOUCHSCREEN_VCHANNEL1) |
729 LRADC_DELAY_KICK | LRADC_DELAY_DELAY(10), /* waste 5 ms */
734 * in order to avoid false measurements, report only samples where
735 * the surface is still touched after the position measurement
737 static void mxs_lradc_finish_touch_event(struct mxs_lradc *lradc, bool valid)
739 /* if it is still touched, report the sample */
740 if (valid && mxs_lradc_check_touch_event(lradc)) {
741 lradc->ts_valid = true;
742 mxs_lradc_report_ts_event(lradc);
745 /* if it is even still touched, continue with the next measurement */
746 if (mxs_lradc_check_touch_event(lradc)) {
747 mxs_lradc_prepare_y_pos(lradc);
751 if (lradc->ts_valid) {
752 /* signal the release */
753 lradc->ts_valid = false;
754 input_report_key(lradc->ts_input, BTN_TOUCH, 0);
755 input_sync(lradc->ts_input);
758 /* if it is released, wait for the next touch via IRQ */
759 lradc->cur_plate = LRADC_TOUCH;
760 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(2));
761 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(3));
762 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ |
763 LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) |
764 LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1), LRADC_CTRL1);
765 mxs_lradc_reg_set(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
768 /* touchscreen's state machine */
769 static void mxs_lradc_handle_touch(struct mxs_lradc *lradc)
771 switch (lradc->cur_plate) {
773 if (mxs_lradc_check_touch_event(lradc))
774 mxs_lradc_start_touch_event(lradc);
775 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ,
780 lradc->ts_y_pos = mxs_lradc_read_raw_channel(lradc,
781 TOUCHSCREEN_VCHANNEL1);
782 mxs_lradc_prepare_x_pos(lradc);
786 lradc->ts_x_pos = mxs_lradc_read_raw_channel(lradc,
787 TOUCHSCREEN_VCHANNEL1);
788 mxs_lradc_prepare_pressure(lradc);
791 case LRADC_SAMPLE_PRESSURE:
792 lradc->ts_pressure = mxs_lradc_read_ts_pressure(lradc,
793 TOUCHSCREEN_VCHANNEL2,
794 TOUCHSCREEN_VCHANNEL1);
795 mxs_lradc_complete_touch_event(lradc);
798 case LRADC_SAMPLE_VALID:
799 mxs_lradc_finish_touch_event(lradc, 1);
807 static int mxs_lradc_read_single(struct iio_dev *iio_dev, int chan, int *val)
809 struct mxs_lradc *lradc = iio_priv(iio_dev);
813 * See if there is no buffered operation in progess. If there is, simply
814 * bail out. This can be improved to support both buffered and raw IO at
815 * the same time, yet the code becomes horribly complicated. Therefore I
816 * applied KISS principle here.
818 ret = mutex_trylock(&lradc->lock);
822 reinit_completion(&lradc->completion);
825 * No buffered operation in progress, map the channel and trigger it.
826 * Virtual channel 0 is always used here as the others are always not
827 * used if doing raw sampling.
829 if (lradc->soc == IMX28_LRADC)
830 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0),
832 mxs_lradc_reg_clear(lradc, 0x1, LRADC_CTRL0);
834 /* Enable / disable the divider per requirement */
835 if (test_bit(chan, &lradc->is_divided))
836 mxs_lradc_reg_set(lradc, 1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
839 mxs_lradc_reg_clear(lradc,
840 1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET, LRADC_CTRL2);
842 /* Clean the slot's previous content, then set new one. */
843 mxs_lradc_reg_clear(lradc, LRADC_CTRL4_LRADCSELECT_MASK(0),
845 mxs_lradc_reg_set(lradc, chan, LRADC_CTRL4);
847 mxs_lradc_reg_wrt(lradc, 0, LRADC_CH(0));
849 /* Enable the IRQ and start sampling the channel. */
850 mxs_lradc_reg_set(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0), LRADC_CTRL1);
851 mxs_lradc_reg_set(lradc, 1 << 0, LRADC_CTRL0);
853 /* Wait for completion on the channel, 1 second max. */
854 ret = wait_for_completion_killable_timeout(&lradc->completion, HZ);
861 *val = readl(lradc->base + LRADC_CH(0)) & LRADC_CH_VALUE_MASK;
865 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0), LRADC_CTRL1);
867 mutex_unlock(&lradc->lock);
872 static int mxs_lradc_read_temp(struct iio_dev *iio_dev, int *val)
876 ret = mxs_lradc_read_single(iio_dev, 8, &min);
877 if (ret != IIO_VAL_INT)
880 ret = mxs_lradc_read_single(iio_dev, 9, &max);
881 if (ret != IIO_VAL_INT)
889 static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
890 const struct iio_chan_spec *chan,
891 int *val, int *val2, long m)
893 struct mxs_lradc *lradc = iio_priv(iio_dev);
896 case IIO_CHAN_INFO_RAW:
897 if (chan->type == IIO_TEMP)
898 return mxs_lradc_read_temp(iio_dev, val);
900 return mxs_lradc_read_single(iio_dev, chan->channel, val);
902 case IIO_CHAN_INFO_SCALE:
903 if (chan->type == IIO_TEMP) {
904 /* From the datasheet, we have to multiply by 1.012 and
909 return IIO_VAL_INT_PLUS_MICRO;
912 *val = lradc->vref_mv[chan->channel];
913 *val2 = chan->scan_type.realbits -
914 test_bit(chan->channel, &lradc->is_divided);
915 return IIO_VAL_FRACTIONAL_LOG2;
917 case IIO_CHAN_INFO_OFFSET:
918 if (chan->type == IIO_TEMP) {
919 /* The calculated value from the ADC is in Kelvin, we
920 * want Celsius for hwmon so the offset is -273.15
921 * The offset is applied before scaling so it is
922 * actually -213.15 * 4 / 1.012 = -1079.644268
927 return IIO_VAL_INT_PLUS_MICRO;
939 static int mxs_lradc_write_raw(struct iio_dev *iio_dev,
940 const struct iio_chan_spec *chan,
941 int val, int val2, long m)
943 struct mxs_lradc *lradc = iio_priv(iio_dev);
944 struct mxs_lradc_scale *scale_avail =
945 lradc->scale_avail[chan->channel];
948 ret = mutex_trylock(&lradc->lock);
953 case IIO_CHAN_INFO_SCALE:
955 if (val == scale_avail[MXS_LRADC_DIV_DISABLED].integer &&
956 val2 == scale_avail[MXS_LRADC_DIV_DISABLED].nano) {
957 /* divider by two disabled */
958 clear_bit(chan->channel, &lradc->is_divided);
960 } else if (val == scale_avail[MXS_LRADC_DIV_ENABLED].integer &&
961 val2 == scale_avail[MXS_LRADC_DIV_ENABLED].nano) {
962 /* divider by two enabled */
963 set_bit(chan->channel, &lradc->is_divided);
973 mutex_unlock(&lradc->lock);
978 static int mxs_lradc_write_raw_get_fmt(struct iio_dev *iio_dev,
979 const struct iio_chan_spec *chan,
982 return IIO_VAL_INT_PLUS_NANO;
985 static ssize_t mxs_lradc_show_scale_available_ch(struct device *dev,
986 struct device_attribute *attr,
990 struct iio_dev *iio = dev_to_iio_dev(dev);
991 struct mxs_lradc *lradc = iio_priv(iio);
994 for (i = 0; i < ARRAY_SIZE(lradc->scale_avail[ch]); i++)
995 len += sprintf(buf + len, "%d.%09u ",
996 lradc->scale_avail[ch][i].integer,
997 lradc->scale_avail[ch][i].nano);
999 len += sprintf(buf + len, "\n");
1004 static ssize_t mxs_lradc_show_scale_available(struct device *dev,
1005 struct device_attribute *attr,
1008 struct iio_dev_attr *iio_attr = to_iio_dev_attr(attr);
1010 return mxs_lradc_show_scale_available_ch(dev, attr, buf,
1014 #define SHOW_SCALE_AVAILABLE_ATTR(ch) \
1015 static IIO_DEVICE_ATTR(in_voltage##ch##_scale_available, S_IRUGO, \
1016 mxs_lradc_show_scale_available, NULL, ch)
1018 SHOW_SCALE_AVAILABLE_ATTR(0);
1019 SHOW_SCALE_AVAILABLE_ATTR(1);
1020 SHOW_SCALE_AVAILABLE_ATTR(2);
1021 SHOW_SCALE_AVAILABLE_ATTR(3);
1022 SHOW_SCALE_AVAILABLE_ATTR(4);
1023 SHOW_SCALE_AVAILABLE_ATTR(5);
1024 SHOW_SCALE_AVAILABLE_ATTR(6);
1025 SHOW_SCALE_AVAILABLE_ATTR(7);
1026 SHOW_SCALE_AVAILABLE_ATTR(10);
1027 SHOW_SCALE_AVAILABLE_ATTR(11);
1028 SHOW_SCALE_AVAILABLE_ATTR(12);
1029 SHOW_SCALE_AVAILABLE_ATTR(13);
1030 SHOW_SCALE_AVAILABLE_ATTR(14);
1031 SHOW_SCALE_AVAILABLE_ATTR(15);
1033 static struct attribute *mxs_lradc_attributes[] = {
1034 &iio_dev_attr_in_voltage0_scale_available.dev_attr.attr,
1035 &iio_dev_attr_in_voltage1_scale_available.dev_attr.attr,
1036 &iio_dev_attr_in_voltage2_scale_available.dev_attr.attr,
1037 &iio_dev_attr_in_voltage3_scale_available.dev_attr.attr,
1038 &iio_dev_attr_in_voltage4_scale_available.dev_attr.attr,
1039 &iio_dev_attr_in_voltage5_scale_available.dev_attr.attr,
1040 &iio_dev_attr_in_voltage6_scale_available.dev_attr.attr,
1041 &iio_dev_attr_in_voltage7_scale_available.dev_attr.attr,
1042 &iio_dev_attr_in_voltage10_scale_available.dev_attr.attr,
1043 &iio_dev_attr_in_voltage11_scale_available.dev_attr.attr,
1044 &iio_dev_attr_in_voltage12_scale_available.dev_attr.attr,
1045 &iio_dev_attr_in_voltage13_scale_available.dev_attr.attr,
1046 &iio_dev_attr_in_voltage14_scale_available.dev_attr.attr,
1047 &iio_dev_attr_in_voltage15_scale_available.dev_attr.attr,
1051 static const struct attribute_group mxs_lradc_attribute_group = {
1052 .attrs = mxs_lradc_attributes,
1055 static const struct iio_info mxs_lradc_iio_info = {
1056 .driver_module = THIS_MODULE,
1057 .read_raw = mxs_lradc_read_raw,
1058 .write_raw = mxs_lradc_write_raw,
1059 .write_raw_get_fmt = mxs_lradc_write_raw_get_fmt,
1060 .attrs = &mxs_lradc_attribute_group,
1063 static int mxs_lradc_ts_open(struct input_dev *dev)
1065 struct mxs_lradc *lradc = input_get_drvdata(dev);
1067 /* Enable the touch-detect circuitry. */
1068 mxs_lradc_enable_touch_detection(lradc);
1073 static void mxs_lradc_disable_ts(struct mxs_lradc *lradc)
1075 /* stop all interrupts from firing */
1076 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN |
1077 LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) |
1078 LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL2), LRADC_CTRL1);
1080 /* Power-down touchscreen touch-detect circuitry. */
1081 mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
1084 static void mxs_lradc_ts_close(struct input_dev *dev)
1086 struct mxs_lradc *lradc = input_get_drvdata(dev);
1088 mxs_lradc_disable_ts(lradc);
1091 static int mxs_lradc_ts_register(struct mxs_lradc *lradc)
1093 struct input_dev *input;
1094 struct device *dev = lradc->dev;
1097 if (!lradc->use_touchscreen)
1100 input = input_allocate_device();
1104 input->name = DRIVER_NAME;
1105 input->id.bustype = BUS_HOST;
1106 input->dev.parent = dev;
1107 input->open = mxs_lradc_ts_open;
1108 input->close = mxs_lradc_ts_close;
1110 __set_bit(EV_ABS, input->evbit);
1111 __set_bit(EV_KEY, input->evbit);
1112 __set_bit(BTN_TOUCH, input->keybit);
1113 input_set_abs_params(input, ABS_X, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0);
1114 input_set_abs_params(input, ABS_Y, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0);
1115 input_set_abs_params(input, ABS_PRESSURE, 0, LRADC_SINGLE_SAMPLE_MASK,
1118 lradc->ts_input = input;
1119 input_set_drvdata(input, lradc);
1120 ret = input_register_device(input);
1122 input_free_device(lradc->ts_input);
1127 static void mxs_lradc_ts_unregister(struct mxs_lradc *lradc)
1129 if (!lradc->use_touchscreen)
1132 mxs_lradc_disable_ts(lradc);
1133 input_unregister_device(lradc->ts_input);
1139 static irqreturn_t mxs_lradc_handle_irq(int irq, void *data)
1141 struct iio_dev *iio = data;
1142 struct mxs_lradc *lradc = iio_priv(iio);
1143 unsigned long reg = readl(lradc->base + LRADC_CTRL1);
1144 uint32_t clr_irq = mxs_lradc_irq_mask(lradc);
1145 const uint32_t ts_irq_mask =
1146 LRADC_CTRL1_TOUCH_DETECT_IRQ |
1147 LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
1148 LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2);
1150 if (!(reg & mxs_lradc_irq_mask(lradc)))
1153 if (lradc->use_touchscreen && (reg & ts_irq_mask)) {
1154 mxs_lradc_handle_touch(lradc);
1156 /* Make sure we don't clear the next conversion's interrupt. */
1157 clr_irq &= ~(LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
1158 LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2));
1161 if (iio_buffer_enabled(iio)) {
1162 if (reg & lradc->buffer_vchans)
1163 iio_trigger_poll(iio->trig, iio_get_time_ns());
1164 } else if (reg & LRADC_CTRL1_LRADC_IRQ(0)) {
1165 complete(&lradc->completion);
1168 mxs_lradc_reg_clear(lradc, reg & clr_irq, LRADC_CTRL1);
1176 static irqreturn_t mxs_lradc_trigger_handler(int irq, void *p)
1178 struct iio_poll_func *pf = p;
1179 struct iio_dev *iio = pf->indio_dev;
1180 struct mxs_lradc *lradc = iio_priv(iio);
1181 const uint32_t chan_value = LRADC_CH_ACCUMULATE |
1182 ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET);
1183 unsigned int i, j = 0;
1185 for_each_set_bit(i, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) {
1186 lradc->buffer[j] = readl(lradc->base + LRADC_CH(j));
1187 mxs_lradc_reg_wrt(lradc, chan_value, LRADC_CH(j));
1188 lradc->buffer[j] &= LRADC_CH_VALUE_MASK;
1189 lradc->buffer[j] /= LRADC_DELAY_TIMER_LOOP;
1193 iio_push_to_buffers_with_timestamp(iio, lradc->buffer, pf->timestamp);
1195 iio_trigger_notify_done(iio->trig);
1200 static int mxs_lradc_configure_trigger(struct iio_trigger *trig, bool state)
1202 struct iio_dev *iio = iio_trigger_get_drvdata(trig);
1203 struct mxs_lradc *lradc = iio_priv(iio);
1204 const uint32_t st = state ? STMP_OFFSET_REG_SET : STMP_OFFSET_REG_CLR;
1206 mxs_lradc_reg_wrt(lradc, LRADC_DELAY_KICK, LRADC_DELAY(0) + st);
1211 static const struct iio_trigger_ops mxs_lradc_trigger_ops = {
1212 .owner = THIS_MODULE,
1213 .set_trigger_state = &mxs_lradc_configure_trigger,
1216 static int mxs_lradc_trigger_init(struct iio_dev *iio)
1219 struct iio_trigger *trig;
1220 struct mxs_lradc *lradc = iio_priv(iio);
1222 trig = iio_trigger_alloc("%s-dev%i", iio->name, iio->id);
1226 trig->dev.parent = lradc->dev;
1227 iio_trigger_set_drvdata(trig, iio);
1228 trig->ops = &mxs_lradc_trigger_ops;
1230 ret = iio_trigger_register(trig);
1232 iio_trigger_free(trig);
1241 static void mxs_lradc_trigger_remove(struct iio_dev *iio)
1243 struct mxs_lradc *lradc = iio_priv(iio);
1245 iio_trigger_unregister(lradc->trig);
1246 iio_trigger_free(lradc->trig);
1249 static int mxs_lradc_buffer_preenable(struct iio_dev *iio)
1251 struct mxs_lradc *lradc = iio_priv(iio);
1252 int ret = 0, chan, ofs = 0;
1253 unsigned long enable = 0;
1254 uint32_t ctrl4_set = 0;
1255 uint32_t ctrl4_clr = 0;
1256 uint32_t ctrl1_irq = 0;
1257 const uint32_t chan_value = LRADC_CH_ACCUMULATE |
1258 ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET);
1259 const int len = bitmap_weight(iio->active_scan_mask,
1260 LRADC_MAX_TOTAL_CHANS);
1266 * Lock the driver so raw access can not be done during buffered
1267 * operation. This simplifies the code a lot.
1269 ret = mutex_trylock(&lradc->lock);
1273 lradc->buffer = kmalloc(len * sizeof(*lradc->buffer), GFP_KERNEL);
1274 if (!lradc->buffer) {
1279 if (lradc->soc == IMX28_LRADC)
1280 mxs_lradc_reg_clear(lradc,
1281 lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
1283 mxs_lradc_reg_clear(lradc, lradc->buffer_vchans, LRADC_CTRL0);
1285 for_each_set_bit(chan, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) {
1286 ctrl4_set |= chan << LRADC_CTRL4_LRADCSELECT_OFFSET(ofs);
1287 ctrl4_clr |= LRADC_CTRL4_LRADCSELECT_MASK(ofs);
1288 ctrl1_irq |= LRADC_CTRL1_LRADC_IRQ_EN(ofs);
1289 mxs_lradc_reg_wrt(lradc, chan_value, LRADC_CH(ofs));
1290 bitmap_set(&enable, ofs, 1);
1294 mxs_lradc_reg_clear(lradc, LRADC_DELAY_TRIGGER_LRADCS_MASK |
1295 LRADC_DELAY_KICK, LRADC_DELAY(0));
1296 mxs_lradc_reg_clear(lradc, ctrl4_clr, LRADC_CTRL4);
1297 mxs_lradc_reg_set(lradc, ctrl4_set, LRADC_CTRL4);
1298 mxs_lradc_reg_set(lradc, ctrl1_irq, LRADC_CTRL1);
1299 mxs_lradc_reg_set(lradc, enable << LRADC_DELAY_TRIGGER_LRADCS_OFFSET,
1305 mutex_unlock(&lradc->lock);
1309 static int mxs_lradc_buffer_postdisable(struct iio_dev *iio)
1311 struct mxs_lradc *lradc = iio_priv(iio);
1313 mxs_lradc_reg_clear(lradc, LRADC_DELAY_TRIGGER_LRADCS_MASK |
1314 LRADC_DELAY_KICK, LRADC_DELAY(0));
1316 mxs_lradc_reg_clear(lradc, lradc->buffer_vchans, LRADC_CTRL0);
1317 if (lradc->soc == IMX28_LRADC)
1318 mxs_lradc_reg_clear(lradc,
1319 lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
1322 kfree(lradc->buffer);
1323 mutex_unlock(&lradc->lock);
1328 static bool mxs_lradc_validate_scan_mask(struct iio_dev *iio,
1329 const unsigned long *mask)
1331 struct mxs_lradc *lradc = iio_priv(iio);
1332 const int map_chans = bitmap_weight(mask, LRADC_MAX_TOTAL_CHANS);
1334 unsigned long rsvd_mask = 0;
1336 if (lradc->use_touchbutton)
1337 rsvd_mask |= CHAN_MASK_TOUCHBUTTON;
1338 if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_4WIRE)
1339 rsvd_mask |= CHAN_MASK_TOUCHSCREEN_4WIRE;
1340 if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE)
1341 rsvd_mask |= CHAN_MASK_TOUCHSCREEN_5WIRE;
1343 if (lradc->use_touchbutton)
1345 if (lradc->use_touchscreen)
1348 /* Test for attempts to map channels with special mode of operation. */
1349 if (bitmap_intersects(mask, &rsvd_mask, LRADC_MAX_TOTAL_CHANS))
1352 /* Test for attempts to map more channels then available slots. */
1353 if (map_chans + rsvd_chans > LRADC_MAX_MAPPED_CHANS)
1359 static const struct iio_buffer_setup_ops mxs_lradc_buffer_ops = {
1360 .preenable = &mxs_lradc_buffer_preenable,
1361 .postenable = &iio_triggered_buffer_postenable,
1362 .predisable = &iio_triggered_buffer_predisable,
1363 .postdisable = &mxs_lradc_buffer_postdisable,
1364 .validate_scan_mask = &mxs_lradc_validate_scan_mask,
1368 * Driver initialization
1371 #define MXS_ADC_CHAN(idx, chan_type) { \
1372 .type = (chan_type), \
1374 .scan_index = (idx), \
1375 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
1376 BIT(IIO_CHAN_INFO_SCALE), \
1381 .realbits = LRADC_RESOLUTION, \
1382 .storagebits = 32, \
1386 static const struct iio_chan_spec mxs_lradc_chan_spec[] = {
1387 MXS_ADC_CHAN(0, IIO_VOLTAGE),
1388 MXS_ADC_CHAN(1, IIO_VOLTAGE),
1389 MXS_ADC_CHAN(2, IIO_VOLTAGE),
1390 MXS_ADC_CHAN(3, IIO_VOLTAGE),
1391 MXS_ADC_CHAN(4, IIO_VOLTAGE),
1392 MXS_ADC_CHAN(5, IIO_VOLTAGE),
1393 MXS_ADC_CHAN(6, IIO_VOLTAGE),
1394 MXS_ADC_CHAN(7, IIO_VOLTAGE), /* VBATT */
1395 /* Combined Temperature sensors */
1400 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
1401 BIT(IIO_CHAN_INFO_OFFSET) |
1402 BIT(IIO_CHAN_INFO_SCALE),
1404 .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
1406 /* Hidden channel to keep indexes */
1413 MXS_ADC_CHAN(10, IIO_VOLTAGE), /* VDDIO */
1414 MXS_ADC_CHAN(11, IIO_VOLTAGE), /* VTH */
1415 MXS_ADC_CHAN(12, IIO_VOLTAGE), /* VDDA */
1416 MXS_ADC_CHAN(13, IIO_VOLTAGE), /* VDDD */
1417 MXS_ADC_CHAN(14, IIO_VOLTAGE), /* VBG */
1418 MXS_ADC_CHAN(15, IIO_VOLTAGE), /* VDD5V */
1421 static int mxs_lradc_hw_init(struct mxs_lradc *lradc)
1423 /* The ADC always uses DELAY CHANNEL 0. */
1424 const uint32_t adc_cfg =
1425 (1 << (LRADC_DELAY_TRIGGER_DELAYS_OFFSET + 0)) |
1426 (LRADC_DELAY_TIMER_PER << LRADC_DELAY_DELAY_OFFSET);
1428 int ret = stmp_reset_block(lradc->base);
1432 /* Configure DELAY CHANNEL 0 for generic ADC sampling. */
1433 mxs_lradc_reg_wrt(lradc, adc_cfg, LRADC_DELAY(0));
1435 /* Disable remaining DELAY CHANNELs */
1436 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(1));
1437 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(2));
1438 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(3));
1440 /* Configure the touchscreen type */
1441 if (lradc->soc == IMX28_LRADC) {
1442 mxs_lradc_reg_clear(lradc, LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
1445 if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE)
1446 mxs_lradc_reg_set(lradc, LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
1450 /* Start internal temperature sensing. */
1451 mxs_lradc_reg_wrt(lradc, 0, LRADC_CTRL2);
1456 static void mxs_lradc_hw_stop(struct mxs_lradc *lradc)
1460 mxs_lradc_reg_clear(lradc, mxs_lradc_irq_en_mask(lradc), LRADC_CTRL1);
1462 for (i = 0; i < LRADC_MAX_DELAY_CHANS; i++)
1463 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(i));
1466 static const struct of_device_id mxs_lradc_dt_ids[] = {
1467 { .compatible = "fsl,imx23-lradc", .data = (void *)IMX23_LRADC, },
1468 { .compatible = "fsl,imx28-lradc", .data = (void *)IMX28_LRADC, },
1471 MODULE_DEVICE_TABLE(of, mxs_lradc_dt_ids);
1473 static int mxs_lradc_probe_touchscreen(struct mxs_lradc *lradc,
1474 struct device_node *lradc_node)
1477 u32 ts_wires = 0, adapt;
1479 ret = of_property_read_u32(lradc_node, "fsl,lradc-touchscreen-wires",
1482 return -ENODEV; /* touchscreen feature disabled */
1486 lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_4WIRE;
1489 if (lradc->soc == IMX28_LRADC) {
1490 lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_5WIRE;
1493 /* fall through an error message for i.MX23 */
1496 "Unsupported number of touchscreen wires (%d)\n",
1501 lradc->over_sample_cnt = 4;
1502 ret = of_property_read_u32(lradc_node, "fsl,ave-ctrl", &adapt);
1504 lradc->over_sample_cnt = adapt;
1506 lradc->over_sample_delay = 2;
1507 ret = of_property_read_u32(lradc_node, "fsl,ave-delay", &adapt);
1509 lradc->over_sample_delay = adapt;
1511 lradc->settling_delay = 10;
1512 ret = of_property_read_u32(lradc_node, "fsl,settling", &adapt);
1514 lradc->settling_delay = adapt;
1519 static int mxs_lradc_probe(struct platform_device *pdev)
1521 const struct of_device_id *of_id =
1522 of_match_device(mxs_lradc_dt_ids, &pdev->dev);
1523 const struct mxs_lradc_of_config *of_cfg =
1524 &mxs_lradc_of_config[(enum mxs_lradc_id)of_id->data];
1525 struct device *dev = &pdev->dev;
1526 struct device_node *node = dev->of_node;
1527 struct mxs_lradc *lradc;
1528 struct iio_dev *iio;
1529 struct resource *iores;
1530 int ret = 0, touch_ret;
1534 /* Allocate the IIO device. */
1535 iio = devm_iio_device_alloc(dev, sizeof(*lradc));
1537 dev_err(dev, "Failed to allocate IIO device\n");
1541 lradc = iio_priv(iio);
1542 lradc->soc = (enum mxs_lradc_id)of_id->data;
1544 /* Grab the memory area */
1545 iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1546 lradc->dev = &pdev->dev;
1547 lradc->base = devm_ioremap_resource(dev, iores);
1548 if (IS_ERR(lradc->base))
1549 return PTR_ERR(lradc->base);
1551 lradc->clk = devm_clk_get(&pdev->dev, NULL);
1552 if (IS_ERR(lradc->clk)) {
1553 dev_err(dev, "Failed to get the delay unit clock\n");
1554 return PTR_ERR(lradc->clk);
1556 ret = clk_prepare_enable(lradc->clk);
1558 dev_err(dev, "Failed to enable the delay unit clock\n");
1562 touch_ret = mxs_lradc_probe_touchscreen(lradc, node);
1565 lradc->buffer_vchans = BUFFER_VCHANS_LIMITED;
1567 lradc->buffer_vchans = BUFFER_VCHANS_ALL;
1569 /* Grab all IRQ sources */
1570 for (i = 0; i < of_cfg->irq_count; i++) {
1571 lradc->irq[i] = platform_get_irq(pdev, i);
1572 if (lradc->irq[i] < 0) {
1573 ret = lradc->irq[i];
1577 ret = devm_request_irq(dev, lradc->irq[i],
1578 mxs_lradc_handle_irq, 0,
1579 of_cfg->irq_name[i], iio);
1584 lradc->vref_mv = of_cfg->vref_mv;
1586 platform_set_drvdata(pdev, iio);
1588 init_completion(&lradc->completion);
1589 mutex_init(&lradc->lock);
1591 iio->name = pdev->name;
1592 iio->dev.parent = &pdev->dev;
1593 iio->info = &mxs_lradc_iio_info;
1594 iio->modes = INDIO_DIRECT_MODE;
1595 iio->channels = mxs_lradc_chan_spec;
1596 iio->num_channels = ARRAY_SIZE(mxs_lradc_chan_spec);
1597 iio->masklength = LRADC_MAX_TOTAL_CHANS;
1599 ret = iio_triggered_buffer_setup(iio, &iio_pollfunc_store_time,
1600 &mxs_lradc_trigger_handler,
1601 &mxs_lradc_buffer_ops);
1605 ret = mxs_lradc_trigger_init(iio);
1609 /* Populate available ADC input ranges */
1610 for (i = 0; i < LRADC_MAX_TOTAL_CHANS; i++) {
1611 for (s = 0; s < ARRAY_SIZE(lradc->scale_avail[i]); s++) {
1613 * [s=0] = optional divider by two disabled (default)
1614 * [s=1] = optional divider by two enabled
1616 * The scale is calculated by doing:
1617 * Vref >> (realbits - s)
1618 * which multiplies by two on the second component
1621 scale_uv = ((u64)lradc->vref_mv[i] * 100000000) >>
1622 (LRADC_RESOLUTION - s);
1623 lradc->scale_avail[i][s].nano =
1624 do_div(scale_uv, 100000000) * 10;
1625 lradc->scale_avail[i][s].integer = scale_uv;
1629 /* Configure the hardware. */
1630 ret = mxs_lradc_hw_init(lradc);
1634 /* Register the touchscreen input device. */
1635 if (touch_ret == 0) {
1636 ret = mxs_lradc_ts_register(lradc);
1638 goto err_ts_register;
1641 /* Register IIO device. */
1642 ret = iio_device_register(iio);
1644 dev_err(dev, "Failed to register IIO device\n");
1651 mxs_lradc_ts_unregister(lradc);
1653 mxs_lradc_hw_stop(lradc);
1655 mxs_lradc_trigger_remove(iio);
1657 iio_triggered_buffer_cleanup(iio);
1659 clk_disable_unprepare(lradc->clk);
1663 static int mxs_lradc_remove(struct platform_device *pdev)
1665 struct iio_dev *iio = platform_get_drvdata(pdev);
1666 struct mxs_lradc *lradc = iio_priv(iio);
1668 iio_device_unregister(iio);
1669 mxs_lradc_ts_unregister(lradc);
1670 mxs_lradc_hw_stop(lradc);
1671 mxs_lradc_trigger_remove(iio);
1672 iio_triggered_buffer_cleanup(iio);
1674 clk_disable_unprepare(lradc->clk);
1678 static struct platform_driver mxs_lradc_driver = {
1680 .name = DRIVER_NAME,
1681 .owner = THIS_MODULE,
1682 .of_match_table = mxs_lradc_dt_ids,
1684 .probe = mxs_lradc_probe,
1685 .remove = mxs_lradc_remove,
1688 module_platform_driver(mxs_lradc_driver);
1690 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
1691 MODULE_DESCRIPTION("Freescale i.MX28 LRADC driver");
1692 MODULE_LICENSE("GPL v2");
1693 MODULE_ALIAS("platform:" DRIVER_NAME);