2 * Freescale MXS 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/bitops.h>
19 #include <linux/clk.h>
20 #include <linux/completion.h>
21 #include <linux/device.h>
22 #include <linux/err.h>
23 #include <linux/input.h>
24 #include <linux/interrupt.h>
26 #include <linux/kernel.h>
27 #include <linux/module.h>
28 #include <linux/mutex.h>
30 #include <linux/of_device.h>
31 #include <linux/platform_device.h>
32 #include <linux/slab.h>
33 #include <linux/stmp_device.h>
34 #include <linux/sysfs.h>
36 #include <linux/iio/buffer.h>
37 #include <linux/iio/iio.h>
38 #include <linux/iio/trigger.h>
39 #include <linux/iio/trigger_consumer.h>
40 #include <linux/iio/triggered_buffer.h>
41 #include <linux/iio/sysfs.h>
43 #define DRIVER_NAME "mxs-lradc"
45 #define LRADC_MAX_DELAY_CHANS 4
46 #define LRADC_MAX_MAPPED_CHANS 8
47 #define LRADC_MAX_TOTAL_CHANS 16
49 #define LRADC_DELAY_TIMER_HZ 2000
52 * Make this runtime configurable if necessary. Currently, if the buffered mode
53 * is enabled, the LRADC takes LRADC_DELAY_TIMER_LOOP samples of data before
54 * triggering IRQ. The sampling happens every (LRADC_DELAY_TIMER_PER / 2000)
55 * seconds. The result is that the samples arrive every 500mS.
57 #define LRADC_DELAY_TIMER_PER 200
58 #define LRADC_DELAY_TIMER_LOOP 5
61 * Once the pen touches the touchscreen, the touchscreen switches from
62 * IRQ-driven mode to polling mode to prevent interrupt storm. The polling
63 * is realized by worker thread, which is called every 20 or so milliseconds.
64 * This gives the touchscreen enough fluency and does not strain the system
67 #define LRADC_TS_SAMPLE_DELAY_MS 5
70 * The LRADC reads the following amount of samples from each touchscreen
71 * channel and the driver then computes average of these.
73 #define LRADC_TS_SAMPLE_AMOUNT 4
80 static const char * const mx23_lradc_irq_names[] = {
81 "mxs-lradc-touchscreen",
92 static const char * const mx28_lradc_irq_names[] = {
93 "mxs-lradc-touchscreen",
100 "mxs-lradc-channel4",
101 "mxs-lradc-channel5",
102 "mxs-lradc-channel6",
103 "mxs-lradc-channel7",
108 struct mxs_lradc_of_config {
110 const char * const *irq_name;
111 const uint32_t *vref_mv;
114 #define VREF_MV_BASE 1850
116 static const uint32_t mx23_vref_mv[LRADC_MAX_TOTAL_CHANS] = {
117 VREF_MV_BASE, /* CH0 */
118 VREF_MV_BASE, /* CH1 */
119 VREF_MV_BASE, /* CH2 */
120 VREF_MV_BASE, /* CH3 */
121 VREF_MV_BASE, /* CH4 */
122 VREF_MV_BASE, /* CH5 */
123 VREF_MV_BASE * 2, /* CH6 VDDIO */
124 VREF_MV_BASE * 4, /* CH7 VBATT */
125 VREF_MV_BASE, /* CH8 Temp sense 0 */
126 VREF_MV_BASE, /* CH9 Temp sense 1 */
127 VREF_MV_BASE, /* CH10 */
128 VREF_MV_BASE, /* CH11 */
129 VREF_MV_BASE, /* CH12 USB_DP */
130 VREF_MV_BASE, /* CH13 USB_DN */
131 VREF_MV_BASE, /* CH14 VBG */
132 VREF_MV_BASE * 4, /* CH15 VDD5V */
135 static const uint32_t mx28_vref_mv[LRADC_MAX_TOTAL_CHANS] = {
136 VREF_MV_BASE, /* CH0 */
137 VREF_MV_BASE, /* CH1 */
138 VREF_MV_BASE, /* CH2 */
139 VREF_MV_BASE, /* CH3 */
140 VREF_MV_BASE, /* CH4 */
141 VREF_MV_BASE, /* CH5 */
142 VREF_MV_BASE, /* CH6 */
143 VREF_MV_BASE * 4, /* CH7 VBATT */
144 VREF_MV_BASE, /* CH8 Temp sense 0 */
145 VREF_MV_BASE, /* CH9 Temp sense 1 */
146 VREF_MV_BASE * 2, /* CH10 VDDIO */
147 VREF_MV_BASE, /* CH11 VTH */
148 VREF_MV_BASE * 2, /* CH12 VDDA */
149 VREF_MV_BASE, /* CH13 VDDD */
150 VREF_MV_BASE, /* CH14 VBG */
151 VREF_MV_BASE * 4, /* CH15 VDD5V */
154 static const struct mxs_lradc_of_config mxs_lradc_of_config[] = {
156 .irq_count = ARRAY_SIZE(mx23_lradc_irq_names),
157 .irq_name = mx23_lradc_irq_names,
158 .vref_mv = mx23_vref_mv,
161 .irq_count = ARRAY_SIZE(mx28_lradc_irq_names),
162 .irq_name = mx28_lradc_irq_names,
163 .vref_mv = mx28_vref_mv,
168 MXS_LRADC_TOUCHSCREEN_NONE = 0,
169 MXS_LRADC_TOUCHSCREEN_4WIRE,
170 MXS_LRADC_TOUCHSCREEN_5WIRE,
174 * Touchscreen handling
176 enum lradc_ts_plate {
180 LRADC_SAMPLE_PRESSURE,
184 enum mxs_lradc_divbytwo {
185 MXS_LRADC_DIV_DISABLED = 0,
186 MXS_LRADC_DIV_ENABLED,
189 struct mxs_lradc_scale {
190 unsigned int integer;
202 struct iio_trigger *trig;
206 struct completion completion;
208 const uint32_t *vref_mv;
209 struct mxs_lradc_scale scale_avail[LRADC_MAX_TOTAL_CHANS][2];
210 unsigned long is_divided;
213 * When the touchscreen is enabled, we give it two private virtual
214 * channels: #6 and #7. This means that only 6 virtual channels (instead
215 * of 8) will be available for buffered capture.
217 #define TOUCHSCREEN_VCHANNEL1 7
218 #define TOUCHSCREEN_VCHANNEL2 6
219 #define BUFFER_VCHANS_LIMITED 0x3f
220 #define BUFFER_VCHANS_ALL 0xff
224 * Furthermore, certain LRADC channels are shared between touchscreen
225 * and/or touch-buttons and generic LRADC block. Therefore when using
226 * either of these, these channels are not available for the regular
227 * sampling. The shared channels are as follows:
229 * CH0 -- Touch button #0
230 * CH1 -- Touch button #1
231 * CH2 -- Touch screen XPUL
232 * CH3 -- Touch screen YPLL
233 * CH4 -- Touch screen XNUL
234 * CH5 -- Touch screen YNLR
235 * CH6 -- Touch screen WIPER (5-wire only)
237 * The bit fields below represents which parts of the LRADC block are
238 * switched into special mode of operation. These channels can not
239 * be sampled as regular LRADC channels. The driver will refuse any
240 * attempt to sample these channels.
242 #define CHAN_MASK_TOUCHBUTTON (BIT(1) | BIT(0))
243 #define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 2)
244 #define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 2)
245 enum mxs_lradc_ts use_touchscreen;
246 bool use_touchbutton;
248 struct input_dev *ts_input;
250 enum mxs_lradc_id soc;
251 enum lradc_ts_plate cur_plate; /* state machine */
255 unsigned ts_pressure;
257 /* handle touchscreen's physical behaviour */
258 /* samples per coordinate */
259 unsigned over_sample_cnt;
260 /* time clocks between samples */
261 unsigned over_sample_delay;
262 /* time in clocks to wait after the plates where switched */
263 unsigned settling_delay;
266 #define LRADC_CTRL0 0x00
267 # define LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE BIT(23)
268 # define LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE BIT(22)
269 # define LRADC_CTRL0_MX28_YNNSW /* YM */ BIT(21)
270 # define LRADC_CTRL0_MX28_YPNSW /* YP */ BIT(20)
271 # define LRADC_CTRL0_MX28_YPPSW /* YP */ BIT(19)
272 # define LRADC_CTRL0_MX28_XNNSW /* XM */ BIT(18)
273 # define LRADC_CTRL0_MX28_XNPSW /* XM */ BIT(17)
274 # define LRADC_CTRL0_MX28_XPPSW /* XP */ BIT(16)
276 # define LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE BIT(20)
277 # define LRADC_CTRL0_MX23_YM BIT(19)
278 # define LRADC_CTRL0_MX23_XM BIT(18)
279 # define LRADC_CTRL0_MX23_YP BIT(17)
280 # define LRADC_CTRL0_MX23_XP BIT(16)
282 # define LRADC_CTRL0_MX28_PLATE_MASK \
283 (LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE | \
284 LRADC_CTRL0_MX28_YNNSW | LRADC_CTRL0_MX28_YPNSW | \
285 LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW | \
286 LRADC_CTRL0_MX28_XNPSW | LRADC_CTRL0_MX28_XPPSW)
288 # define LRADC_CTRL0_MX23_PLATE_MASK \
289 (LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE | \
290 LRADC_CTRL0_MX23_YM | LRADC_CTRL0_MX23_XM | \
291 LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_XP)
293 #define LRADC_CTRL1 0x10
294 #define LRADC_CTRL1_TOUCH_DETECT_IRQ_EN BIT(24)
295 #define LRADC_CTRL1_LRADC_IRQ_EN(n) (1 << ((n) + 16))
296 #define LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK (0x1fff << 16)
297 #define LRADC_CTRL1_MX23_LRADC_IRQ_EN_MASK (0x01ff << 16)
298 #define LRADC_CTRL1_LRADC_IRQ_EN_OFFSET 16
299 #define LRADC_CTRL1_TOUCH_DETECT_IRQ BIT(8)
300 #define LRADC_CTRL1_LRADC_IRQ(n) (1 << (n))
301 #define LRADC_CTRL1_MX28_LRADC_IRQ_MASK 0x1fff
302 #define LRADC_CTRL1_MX23_LRADC_IRQ_MASK 0x01ff
303 #define LRADC_CTRL1_LRADC_IRQ_OFFSET 0
305 #define LRADC_CTRL2 0x20
306 #define LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET 24
307 #define LRADC_CTRL2_TEMPSENSE_PWD BIT(15)
309 #define LRADC_STATUS 0x40
310 #define LRADC_STATUS_TOUCH_DETECT_RAW BIT(0)
312 #define LRADC_CH(n) (0x50 + (0x10 * (n)))
313 #define LRADC_CH_ACCUMULATE BIT(29)
314 #define LRADC_CH_NUM_SAMPLES_MASK (0x1f << 24)
315 #define LRADC_CH_NUM_SAMPLES_OFFSET 24
316 #define LRADC_CH_NUM_SAMPLES(x) \
317 ((x) << LRADC_CH_NUM_SAMPLES_OFFSET)
318 #define LRADC_CH_VALUE_MASK 0x3ffff
319 #define LRADC_CH_VALUE_OFFSET 0
321 #define LRADC_DELAY(n) (0xd0 + (0x10 * (n)))
322 #define LRADC_DELAY_TRIGGER_LRADCS_MASK (0xff << 24)
323 #define LRADC_DELAY_TRIGGER_LRADCS_OFFSET 24
324 #define LRADC_DELAY_TRIGGER(x) \
325 (((x) << LRADC_DELAY_TRIGGER_LRADCS_OFFSET) & \
326 LRADC_DELAY_TRIGGER_LRADCS_MASK)
327 #define LRADC_DELAY_KICK (1 << 20)
328 #define LRADC_DELAY_TRIGGER_DELAYS_MASK (0xf << 16)
329 #define LRADC_DELAY_TRIGGER_DELAYS_OFFSET 16
330 #define LRADC_DELAY_TRIGGER_DELAYS(x) \
331 (((x) << LRADC_DELAY_TRIGGER_DELAYS_OFFSET) & \
332 LRADC_DELAY_TRIGGER_DELAYS_MASK)
333 #define LRADC_DELAY_LOOP_COUNT_MASK (0x1f << 11)
334 #define LRADC_DELAY_LOOP_COUNT_OFFSET 11
335 #define LRADC_DELAY_LOOP(x) \
336 (((x) << LRADC_DELAY_LOOP_COUNT_OFFSET) & \
337 LRADC_DELAY_LOOP_COUNT_MASK)
338 #define LRADC_DELAY_DELAY_MASK 0x7ff
339 #define LRADC_DELAY_DELAY_OFFSET 0
340 #define LRADC_DELAY_DELAY(x) \
341 (((x) << LRADC_DELAY_DELAY_OFFSET) & \
342 LRADC_DELAY_DELAY_MASK)
344 #define LRADC_CTRL4 0x140
345 #define LRADC_CTRL4_LRADCSELECT_MASK(n) (0xf << ((n) * 4))
346 #define LRADC_CTRL4_LRADCSELECT_OFFSET(n) ((n) * 4)
347 #define LRADC_CTRL4_LRADCSELECT(n, x) \
348 (((x) << LRADC_CTRL4_LRADCSELECT_OFFSET(n)) & \
349 LRADC_CTRL4_LRADCSELECT_MASK(n))
351 #define LRADC_RESOLUTION 12
352 #define LRADC_SINGLE_SAMPLE_MASK ((1 << LRADC_RESOLUTION) - 1)
354 static void mxs_lradc_reg_set(struct mxs_lradc *lradc, u32 val, u32 reg)
356 writel(val, lradc->base + reg + STMP_OFFSET_REG_SET);
359 static void mxs_lradc_reg_clear(struct mxs_lradc *lradc, u32 val, u32 reg)
361 writel(val, lradc->base + reg + STMP_OFFSET_REG_CLR);
364 static void mxs_lradc_reg_wrt(struct mxs_lradc *lradc, u32 val, u32 reg)
366 writel(val, lradc->base + reg);
369 static u32 mxs_lradc_plate_mask(struct mxs_lradc *lradc)
371 if (lradc->soc == IMX23_LRADC)
372 return LRADC_CTRL0_MX23_PLATE_MASK;
373 return LRADC_CTRL0_MX28_PLATE_MASK;
376 static u32 mxs_lradc_irq_en_mask(struct mxs_lradc *lradc)
378 if (lradc->soc == IMX23_LRADC)
379 return LRADC_CTRL1_MX23_LRADC_IRQ_EN_MASK;
380 return LRADC_CTRL1_MX28_LRADC_IRQ_EN_MASK;
383 static u32 mxs_lradc_irq_mask(struct mxs_lradc *lradc)
385 if (lradc->soc == IMX23_LRADC)
386 return LRADC_CTRL1_MX23_LRADC_IRQ_MASK;
387 return LRADC_CTRL1_MX28_LRADC_IRQ_MASK;
390 static u32 mxs_lradc_touch_detect_bit(struct mxs_lradc *lradc)
392 if (lradc->soc == IMX23_LRADC)
393 return LRADC_CTRL0_MX23_TOUCH_DETECT_ENABLE;
394 return LRADC_CTRL0_MX28_TOUCH_DETECT_ENABLE;
397 static u32 mxs_lradc_drive_x_plate(struct mxs_lradc *lradc)
399 if (lradc->soc == IMX23_LRADC)
400 return LRADC_CTRL0_MX23_XP | LRADC_CTRL0_MX23_XM;
401 return LRADC_CTRL0_MX28_XPPSW | LRADC_CTRL0_MX28_XNNSW;
404 static u32 mxs_lradc_drive_y_plate(struct mxs_lradc *lradc)
406 if (lradc->soc == IMX23_LRADC)
407 return LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_YM;
408 return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_YNNSW;
411 static u32 mxs_lradc_drive_pressure(struct mxs_lradc *lradc)
413 if (lradc->soc == IMX23_LRADC)
414 return LRADC_CTRL0_MX23_YP | LRADC_CTRL0_MX23_XM;
415 return LRADC_CTRL0_MX28_YPPSW | LRADC_CTRL0_MX28_XNNSW;
418 static bool mxs_lradc_check_touch_event(struct mxs_lradc *lradc)
420 return !!(readl(lradc->base + LRADC_STATUS) &
421 LRADC_STATUS_TOUCH_DETECT_RAW);
424 static void mxs_lradc_map_channel(struct mxs_lradc *lradc, unsigned vch,
427 mxs_lradc_reg_clear(lradc, LRADC_CTRL4_LRADCSELECT_MASK(vch),
429 mxs_lradc_reg_set(lradc, LRADC_CTRL4_LRADCSELECT(vch, ch), LRADC_CTRL4);
432 static void mxs_lradc_setup_ts_channel(struct mxs_lradc *lradc, unsigned ch)
435 * prepare for oversampling conversion
437 * from the datasheet:
438 * "The ACCUMULATE bit in the appropriate channel register
439 * HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
440 * otherwise, the IRQs will not fire."
442 mxs_lradc_reg_wrt(lradc, LRADC_CH_ACCUMULATE |
443 LRADC_CH_NUM_SAMPLES(lradc->over_sample_cnt - 1),
446 /* from the datasheet:
447 * "Software must clear this register in preparation for a
448 * multi-cycle accumulation.
450 mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch));
453 * prepare the delay/loop unit according to the oversampling count
455 * from the datasheet:
456 * "The DELAY fields in HW_LRADC_DELAY0, HW_LRADC_DELAY1,
457 * HW_LRADC_DELAY2, and HW_LRADC_DELAY3 must be non-zero; otherwise,
458 * the LRADC will not trigger the delay group."
460 mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(1 << ch) |
461 LRADC_DELAY_TRIGGER_DELAYS(0) |
462 LRADC_DELAY_LOOP(lradc->over_sample_cnt - 1) |
463 LRADC_DELAY_DELAY(lradc->over_sample_delay - 1),
466 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(ch), LRADC_CTRL1);
469 * after changing the touchscreen plates setting
470 * the signals need some initial time to settle. Start the
471 * SoC's delay unit and start the conversion later
474 mxs_lradc_reg_wrt(lradc,
475 LRADC_DELAY_TRIGGER(0) | /* don't trigger ADC */
476 LRADC_DELAY_TRIGGER_DELAYS(BIT(3)) | /* trigger DELAY unit#3 */
478 LRADC_DELAY_DELAY(lradc->settling_delay),
483 * Pressure detection is special:
484 * We want to do both required measurements for the pressure detection in
485 * one turn. Use the hardware features to chain both conversions and let the
486 * hardware report one interrupt if both conversions are done
488 static void mxs_lradc_setup_ts_pressure(struct mxs_lradc *lradc, unsigned ch1,
494 * prepare for oversampling conversion
496 * from the datasheet:
497 * "The ACCUMULATE bit in the appropriate channel register
498 * HW_LRADC_CHn must be set to 1 if NUM_SAMPLES is greater then 0;
499 * otherwise, the IRQs will not fire."
501 reg = LRADC_CH_ACCUMULATE |
502 LRADC_CH_NUM_SAMPLES(lradc->over_sample_cnt - 1);
503 mxs_lradc_reg_wrt(lradc, reg, LRADC_CH(ch1));
504 mxs_lradc_reg_wrt(lradc, reg, LRADC_CH(ch2));
506 /* from the datasheet:
507 * "Software must clear this register in preparation for a
508 * multi-cycle accumulation.
510 mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch1));
511 mxs_lradc_reg_clear(lradc, LRADC_CH_VALUE_MASK, LRADC_CH(ch2));
513 /* prepare the delay/loop unit according to the oversampling count */
514 mxs_lradc_reg_wrt(lradc, LRADC_DELAY_TRIGGER(1 << ch1) |
515 LRADC_DELAY_TRIGGER(1 << ch2) | /* start both channels */
516 LRADC_DELAY_TRIGGER_DELAYS(0) |
517 LRADC_DELAY_LOOP(lradc->over_sample_cnt - 1) |
518 LRADC_DELAY_DELAY(lradc->over_sample_delay - 1),
521 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ(ch2), LRADC_CTRL1);
524 * after changing the touchscreen plates setting
525 * the signals need some initial time to settle. Start the
526 * SoC's delay unit and start the conversion later
529 mxs_lradc_reg_wrt(lradc,
530 LRADC_DELAY_TRIGGER(0) | /* don't trigger ADC */
531 LRADC_DELAY_TRIGGER_DELAYS(BIT(3)) | /* trigger DELAY unit#3 */
533 LRADC_DELAY_DELAY(lradc->settling_delay), LRADC_DELAY(2));
536 static unsigned mxs_lradc_read_raw_channel(struct mxs_lradc *lradc,
540 unsigned num_samples, val;
542 reg = readl(lradc->base + LRADC_CH(channel));
543 if (reg & LRADC_CH_ACCUMULATE)
544 num_samples = lradc->over_sample_cnt;
548 val = (reg & LRADC_CH_VALUE_MASK) >> LRADC_CH_VALUE_OFFSET;
549 return val / num_samples;
552 static unsigned mxs_lradc_read_ts_pressure(struct mxs_lradc *lradc,
553 unsigned ch1, unsigned ch2)
556 unsigned pressure, m1, m2;
558 mask = LRADC_CTRL1_LRADC_IRQ(ch1) | LRADC_CTRL1_LRADC_IRQ(ch2);
559 reg = readl(lradc->base + LRADC_CTRL1) & mask;
561 while (reg != mask) {
562 reg = readl(lradc->base + LRADC_CTRL1) & mask;
563 dev_dbg(lradc->dev, "One channel is still busy: %X\n", reg);
566 m1 = mxs_lradc_read_raw_channel(lradc, ch1);
567 m2 = mxs_lradc_read_raw_channel(lradc, ch2);
570 dev_warn(lradc->dev, "Cannot calculate pressure\n");
571 return 1 << (LRADC_RESOLUTION - 1);
574 /* simply scale the value from 0 ... max ADC resolution */
576 pressure *= (1 << LRADC_RESOLUTION);
579 dev_dbg(lradc->dev, "Pressure = %u\n", pressure);
589 * YP(open)--+-------------+
592 * YM(-)--+-------------+ |
597 * "weak+" means 200k Ohm VDDIO
600 static void mxs_lradc_setup_touch_detection(struct mxs_lradc *lradc)
603 * In order to detect a touch event the 'touch detect enable' bit
605 * - a weak pullup to the X+ connector
606 * - a strong ground at the Y- connector
608 mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
609 mxs_lradc_reg_set(lradc, mxs_lradc_touch_detect_bit(lradc),
614 * YP(meas)--+-------------+
617 * YM(open)--+-------------+ |
622 * (+) means here 1.85 V
625 static void mxs_lradc_prepare_x_pos(struct mxs_lradc *lradc)
627 mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
628 mxs_lradc_reg_set(lradc, mxs_lradc_drive_x_plate(lradc), LRADC_CTRL0);
630 lradc->cur_plate = LRADC_SAMPLE_X;
631 mxs_lradc_map_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_YP);
632 mxs_lradc_setup_ts_channel(lradc, TOUCHSCREEN_VCHANNEL1);
636 * YP(+)--+-------------+
639 * YM(-)--+-------------+ |
644 * (+) means here 1.85 V
647 static void mxs_lradc_prepare_y_pos(struct mxs_lradc *lradc)
649 mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
650 mxs_lradc_reg_set(lradc, mxs_lradc_drive_y_plate(lradc), LRADC_CTRL0);
652 lradc->cur_plate = LRADC_SAMPLE_Y;
653 mxs_lradc_map_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_XM);
654 mxs_lradc_setup_ts_channel(lradc, TOUCHSCREEN_VCHANNEL1);
658 * YP(+)--+-------------+
661 * YM(meas)--+-------------+ |
666 * (+) means here 1.85 V
669 static void mxs_lradc_prepare_pressure(struct mxs_lradc *lradc)
671 mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
672 mxs_lradc_reg_set(lradc, mxs_lradc_drive_pressure(lradc), LRADC_CTRL0);
674 lradc->cur_plate = LRADC_SAMPLE_PRESSURE;
675 mxs_lradc_map_channel(lradc, TOUCHSCREEN_VCHANNEL1, TS_CH_YM);
676 mxs_lradc_map_channel(lradc, TOUCHSCREEN_VCHANNEL2, TS_CH_XP);
677 mxs_lradc_setup_ts_pressure(lradc, TOUCHSCREEN_VCHANNEL2,
678 TOUCHSCREEN_VCHANNEL1);
681 static void mxs_lradc_enable_touch_detection(struct mxs_lradc *lradc)
683 mxs_lradc_setup_touch_detection(lradc);
685 lradc->cur_plate = LRADC_TOUCH;
686 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ |
687 LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
688 mxs_lradc_reg_set(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
691 static void mxs_lradc_start_touch_event(struct mxs_lradc *lradc)
693 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN,
695 mxs_lradc_reg_set(lradc,
696 LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1), LRADC_CTRL1);
698 * start with the Y-pos, because it uses nearly the same plate
699 * settings like the touch detection
701 mxs_lradc_prepare_y_pos(lradc);
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(TOUCHSCREEN_VCHANNEL1));
722 mxs_lradc_reg_clear(lradc,
723 LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
724 LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2), LRADC_CTRL1);
725 mxs_lradc_reg_wrt(lradc,
726 LRADC_DELAY_TRIGGER(1 << TOUCHSCREEN_VCHANNEL1) |
727 LRADC_DELAY_KICK | LRADC_DELAY_DELAY(10), /* waste 5 ms */
732 * in order to avoid false measurements, report only samples where
733 * the surface is still touched after the position measurement
735 static void mxs_lradc_finish_touch_event(struct mxs_lradc *lradc, bool valid)
737 /* if it is still touched, report the sample */
738 if (valid && mxs_lradc_check_touch_event(lradc)) {
739 lradc->ts_valid = true;
740 mxs_lradc_report_ts_event(lradc);
743 /* if it is even still touched, continue with the next measurement */
744 if (mxs_lradc_check_touch_event(lradc)) {
745 mxs_lradc_prepare_y_pos(lradc);
749 if (lradc->ts_valid) {
750 /* signal the release */
751 lradc->ts_valid = false;
752 input_report_key(lradc->ts_input, BTN_TOUCH, 0);
753 input_sync(lradc->ts_input);
756 /* if it is released, wait for the next touch via IRQ */
757 lradc->cur_plate = LRADC_TOUCH;
758 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(2));
759 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(3));
760 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ |
761 LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) |
762 LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1), LRADC_CTRL1);
763 mxs_lradc_reg_set(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN, LRADC_CTRL1);
766 /* touchscreen's state machine */
767 static void mxs_lradc_handle_touch(struct mxs_lradc *lradc)
769 switch (lradc->cur_plate) {
771 if (mxs_lradc_check_touch_event(lradc))
772 mxs_lradc_start_touch_event(lradc);
773 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ,
778 lradc->ts_y_pos = mxs_lradc_read_raw_channel(lradc,
779 TOUCHSCREEN_VCHANNEL1);
780 mxs_lradc_prepare_x_pos(lradc);
784 lradc->ts_x_pos = mxs_lradc_read_raw_channel(lradc,
785 TOUCHSCREEN_VCHANNEL1);
786 mxs_lradc_prepare_pressure(lradc);
789 case LRADC_SAMPLE_PRESSURE:
790 lradc->ts_pressure = mxs_lradc_read_ts_pressure(lradc,
791 TOUCHSCREEN_VCHANNEL2,
792 TOUCHSCREEN_VCHANNEL1);
793 mxs_lradc_complete_touch_event(lradc);
796 case LRADC_SAMPLE_VALID:
797 mxs_lradc_finish_touch_event(lradc, 1);
805 static int mxs_lradc_read_single(struct iio_dev *iio_dev, int chan, int *val)
807 struct mxs_lradc *lradc = iio_priv(iio_dev);
811 * See if there is no buffered operation in progress. If there is, simply
812 * bail out. This can be improved to support both buffered and raw IO at
813 * the same time, yet the code becomes horribly complicated. Therefore I
814 * applied KISS principle here.
816 ret = mutex_trylock(&lradc->lock);
820 reinit_completion(&lradc->completion);
823 * No buffered operation in progress, map the channel and trigger it.
824 * Virtual channel 0 is always used here as the others are always not
825 * used if doing raw sampling.
827 if (lradc->soc == IMX28_LRADC)
828 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0),
830 mxs_lradc_reg_clear(lradc, 0x1, LRADC_CTRL0);
832 /* Enable / disable the divider per requirement */
833 if (test_bit(chan, &lradc->is_divided))
834 mxs_lradc_reg_set(lradc, 1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
837 mxs_lradc_reg_clear(lradc,
838 1 << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET, LRADC_CTRL2);
840 /* Clean the slot's previous content, then set new one. */
841 mxs_lradc_reg_clear(lradc, LRADC_CTRL4_LRADCSELECT_MASK(0),
843 mxs_lradc_reg_set(lradc, chan, LRADC_CTRL4);
845 mxs_lradc_reg_wrt(lradc, 0, LRADC_CH(0));
847 /* Enable the IRQ and start sampling the channel. */
848 mxs_lradc_reg_set(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0), LRADC_CTRL1);
849 mxs_lradc_reg_set(lradc, BIT(0), LRADC_CTRL0);
851 /* Wait for completion on the channel, 1 second max. */
852 ret = wait_for_completion_killable_timeout(&lradc->completion, HZ);
859 *val = readl(lradc->base + LRADC_CH(0)) & LRADC_CH_VALUE_MASK;
863 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_LRADC_IRQ_EN(0), LRADC_CTRL1);
865 mutex_unlock(&lradc->lock);
870 static int mxs_lradc_read_temp(struct iio_dev *iio_dev, int *val)
874 ret = mxs_lradc_read_single(iio_dev, 8, &min);
875 if (ret != IIO_VAL_INT)
878 ret = mxs_lradc_read_single(iio_dev, 9, &max);
879 if (ret != IIO_VAL_INT)
887 static int mxs_lradc_read_raw(struct iio_dev *iio_dev,
888 const struct iio_chan_spec *chan,
889 int *val, int *val2, long m)
891 struct mxs_lradc *lradc = iio_priv(iio_dev);
894 case IIO_CHAN_INFO_RAW:
895 if (chan->type == IIO_TEMP)
896 return mxs_lradc_read_temp(iio_dev, val);
898 return mxs_lradc_read_single(iio_dev, chan->channel, val);
900 case IIO_CHAN_INFO_SCALE:
901 if (chan->type == IIO_TEMP) {
902 /* From the datasheet, we have to multiply by 1.012 and
907 return IIO_VAL_INT_PLUS_MICRO;
910 *val = lradc->vref_mv[chan->channel];
911 *val2 = chan->scan_type.realbits -
912 test_bit(chan->channel, &lradc->is_divided);
913 return IIO_VAL_FRACTIONAL_LOG2;
915 case IIO_CHAN_INFO_OFFSET:
916 if (chan->type == IIO_TEMP) {
917 /* The calculated value from the ADC is in Kelvin, we
918 * want Celsius for hwmon so the offset is -273.15
919 * The offset is applied before scaling so it is
920 * actually -213.15 * 4 / 1.012 = -1079.644268
925 return IIO_VAL_INT_PLUS_MICRO;
937 static int mxs_lradc_write_raw(struct iio_dev *iio_dev,
938 const struct iio_chan_spec *chan,
939 int val, int val2, long m)
941 struct mxs_lradc *lradc = iio_priv(iio_dev);
942 struct mxs_lradc_scale *scale_avail =
943 lradc->scale_avail[chan->channel];
946 ret = mutex_trylock(&lradc->lock);
951 case IIO_CHAN_INFO_SCALE:
953 if (val == scale_avail[MXS_LRADC_DIV_DISABLED].integer &&
954 val2 == scale_avail[MXS_LRADC_DIV_DISABLED].nano) {
955 /* divider by two disabled */
956 clear_bit(chan->channel, &lradc->is_divided);
958 } else if (val == scale_avail[MXS_LRADC_DIV_ENABLED].integer &&
959 val2 == scale_avail[MXS_LRADC_DIV_ENABLED].nano) {
960 /* divider by two enabled */
961 set_bit(chan->channel, &lradc->is_divided);
971 mutex_unlock(&lradc->lock);
976 static int mxs_lradc_write_raw_get_fmt(struct iio_dev *iio_dev,
977 const struct iio_chan_spec *chan,
980 return IIO_VAL_INT_PLUS_NANO;
983 static ssize_t mxs_lradc_show_scale_available_ch(struct device *dev,
984 struct device_attribute *attr,
988 struct iio_dev *iio = dev_to_iio_dev(dev);
989 struct mxs_lradc *lradc = iio_priv(iio);
992 for (i = 0; i < ARRAY_SIZE(lradc->scale_avail[ch]); i++)
993 len += sprintf(buf + len, "%u.%09u ",
994 lradc->scale_avail[ch][i].integer,
995 lradc->scale_avail[ch][i].nano);
997 len += sprintf(buf + len, "\n");
1002 static ssize_t mxs_lradc_show_scale_available(struct device *dev,
1003 struct device_attribute *attr,
1006 struct iio_dev_attr *iio_attr = to_iio_dev_attr(attr);
1008 return mxs_lradc_show_scale_available_ch(dev, attr, buf,
1012 #define SHOW_SCALE_AVAILABLE_ATTR(ch) \
1013 static IIO_DEVICE_ATTR(in_voltage##ch##_scale_available, S_IRUGO, \
1014 mxs_lradc_show_scale_available, NULL, ch)
1016 SHOW_SCALE_AVAILABLE_ATTR(0);
1017 SHOW_SCALE_AVAILABLE_ATTR(1);
1018 SHOW_SCALE_AVAILABLE_ATTR(2);
1019 SHOW_SCALE_AVAILABLE_ATTR(3);
1020 SHOW_SCALE_AVAILABLE_ATTR(4);
1021 SHOW_SCALE_AVAILABLE_ATTR(5);
1022 SHOW_SCALE_AVAILABLE_ATTR(6);
1023 SHOW_SCALE_AVAILABLE_ATTR(7);
1024 SHOW_SCALE_AVAILABLE_ATTR(10);
1025 SHOW_SCALE_AVAILABLE_ATTR(11);
1026 SHOW_SCALE_AVAILABLE_ATTR(12);
1027 SHOW_SCALE_AVAILABLE_ATTR(13);
1028 SHOW_SCALE_AVAILABLE_ATTR(14);
1029 SHOW_SCALE_AVAILABLE_ATTR(15);
1031 static struct attribute *mxs_lradc_attributes[] = {
1032 &iio_dev_attr_in_voltage0_scale_available.dev_attr.attr,
1033 &iio_dev_attr_in_voltage1_scale_available.dev_attr.attr,
1034 &iio_dev_attr_in_voltage2_scale_available.dev_attr.attr,
1035 &iio_dev_attr_in_voltage3_scale_available.dev_attr.attr,
1036 &iio_dev_attr_in_voltage4_scale_available.dev_attr.attr,
1037 &iio_dev_attr_in_voltage5_scale_available.dev_attr.attr,
1038 &iio_dev_attr_in_voltage6_scale_available.dev_attr.attr,
1039 &iio_dev_attr_in_voltage7_scale_available.dev_attr.attr,
1040 &iio_dev_attr_in_voltage10_scale_available.dev_attr.attr,
1041 &iio_dev_attr_in_voltage11_scale_available.dev_attr.attr,
1042 &iio_dev_attr_in_voltage12_scale_available.dev_attr.attr,
1043 &iio_dev_attr_in_voltage13_scale_available.dev_attr.attr,
1044 &iio_dev_attr_in_voltage14_scale_available.dev_attr.attr,
1045 &iio_dev_attr_in_voltage15_scale_available.dev_attr.attr,
1049 static const struct attribute_group mxs_lradc_attribute_group = {
1050 .attrs = mxs_lradc_attributes,
1053 static const struct iio_info mxs_lradc_iio_info = {
1054 .driver_module = THIS_MODULE,
1055 .read_raw = mxs_lradc_read_raw,
1056 .write_raw = mxs_lradc_write_raw,
1057 .write_raw_get_fmt = mxs_lradc_write_raw_get_fmt,
1058 .attrs = &mxs_lradc_attribute_group,
1061 static int mxs_lradc_ts_open(struct input_dev *dev)
1063 struct mxs_lradc *lradc = input_get_drvdata(dev);
1065 /* Enable the touch-detect circuitry. */
1066 mxs_lradc_enable_touch_detection(lradc);
1071 static void mxs_lradc_disable_ts(struct mxs_lradc *lradc)
1073 /* stop all interrupts from firing */
1074 mxs_lradc_reg_clear(lradc, LRADC_CTRL1_TOUCH_DETECT_IRQ_EN |
1075 LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL1) |
1076 LRADC_CTRL1_LRADC_IRQ_EN(TOUCHSCREEN_VCHANNEL2), LRADC_CTRL1);
1078 /* Power-down touchscreen touch-detect circuitry. */
1079 mxs_lradc_reg_clear(lradc, mxs_lradc_plate_mask(lradc), LRADC_CTRL0);
1082 static void mxs_lradc_ts_close(struct input_dev *dev)
1084 struct mxs_lradc *lradc = input_get_drvdata(dev);
1086 mxs_lradc_disable_ts(lradc);
1089 static int mxs_lradc_ts_register(struct mxs_lradc *lradc)
1091 struct input_dev *input;
1092 struct device *dev = lradc->dev;
1095 if (!lradc->use_touchscreen)
1098 input = input_allocate_device();
1102 input->name = DRIVER_NAME;
1103 input->id.bustype = BUS_HOST;
1104 input->dev.parent = dev;
1105 input->open = mxs_lradc_ts_open;
1106 input->close = mxs_lradc_ts_close;
1108 __set_bit(EV_ABS, input->evbit);
1109 __set_bit(EV_KEY, input->evbit);
1110 __set_bit(BTN_TOUCH, input->keybit);
1111 input_set_abs_params(input, ABS_X, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0);
1112 input_set_abs_params(input, ABS_Y, 0, LRADC_SINGLE_SAMPLE_MASK, 0, 0);
1113 input_set_abs_params(input, ABS_PRESSURE, 0, LRADC_SINGLE_SAMPLE_MASK,
1116 lradc->ts_input = input;
1117 input_set_drvdata(input, lradc);
1118 ret = input_register_device(input);
1120 input_free_device(lradc->ts_input);
1125 static void mxs_lradc_ts_unregister(struct mxs_lradc *lradc)
1127 if (!lradc->use_touchscreen)
1130 mxs_lradc_disable_ts(lradc);
1131 input_unregister_device(lradc->ts_input);
1137 static irqreturn_t mxs_lradc_handle_irq(int irq, void *data)
1139 struct iio_dev *iio = data;
1140 struct mxs_lradc *lradc = iio_priv(iio);
1141 unsigned long reg = readl(lradc->base + LRADC_CTRL1);
1142 uint32_t clr_irq = mxs_lradc_irq_mask(lradc);
1143 const uint32_t ts_irq_mask =
1144 LRADC_CTRL1_TOUCH_DETECT_IRQ |
1145 LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
1146 LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2);
1148 if (!(reg & mxs_lradc_irq_mask(lradc)))
1151 if (lradc->use_touchscreen && (reg & ts_irq_mask)) {
1152 mxs_lradc_handle_touch(lradc);
1154 /* Make sure we don't clear the next conversion's interrupt. */
1155 clr_irq &= ~(LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL1) |
1156 LRADC_CTRL1_LRADC_IRQ(TOUCHSCREEN_VCHANNEL2));
1159 if (iio_buffer_enabled(iio)) {
1160 if (reg & lradc->buffer_vchans)
1161 iio_trigger_poll(iio->trig);
1162 } else if (reg & LRADC_CTRL1_LRADC_IRQ(0)) {
1163 complete(&lradc->completion);
1166 mxs_lradc_reg_clear(lradc, reg & clr_irq, LRADC_CTRL1);
1174 static irqreturn_t mxs_lradc_trigger_handler(int irq, void *p)
1176 struct iio_poll_func *pf = p;
1177 struct iio_dev *iio = pf->indio_dev;
1178 struct mxs_lradc *lradc = iio_priv(iio);
1179 const uint32_t chan_value = LRADC_CH_ACCUMULATE |
1180 ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET);
1181 unsigned int i, j = 0;
1183 for_each_set_bit(i, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) {
1184 lradc->buffer[j] = readl(lradc->base + LRADC_CH(j));
1185 mxs_lradc_reg_wrt(lradc, chan_value, LRADC_CH(j));
1186 lradc->buffer[j] &= LRADC_CH_VALUE_MASK;
1187 lradc->buffer[j] /= LRADC_DELAY_TIMER_LOOP;
1191 iio_push_to_buffers_with_timestamp(iio, lradc->buffer, pf->timestamp);
1193 iio_trigger_notify_done(iio->trig);
1198 static int mxs_lradc_configure_trigger(struct iio_trigger *trig, bool state)
1200 struct iio_dev *iio = iio_trigger_get_drvdata(trig);
1201 struct mxs_lradc *lradc = iio_priv(iio);
1202 const uint32_t st = state ? STMP_OFFSET_REG_SET : STMP_OFFSET_REG_CLR;
1204 mxs_lradc_reg_wrt(lradc, LRADC_DELAY_KICK, LRADC_DELAY(0) + st);
1209 static const struct iio_trigger_ops mxs_lradc_trigger_ops = {
1210 .owner = THIS_MODULE,
1211 .set_trigger_state = &mxs_lradc_configure_trigger,
1214 static int mxs_lradc_trigger_init(struct iio_dev *iio)
1217 struct iio_trigger *trig;
1218 struct mxs_lradc *lradc = iio_priv(iio);
1220 trig = iio_trigger_alloc("%s-dev%i", iio->name, iio->id);
1224 trig->dev.parent = lradc->dev;
1225 iio_trigger_set_drvdata(trig, iio);
1226 trig->ops = &mxs_lradc_trigger_ops;
1228 ret = iio_trigger_register(trig);
1230 iio_trigger_free(trig);
1239 static void mxs_lradc_trigger_remove(struct iio_dev *iio)
1241 struct mxs_lradc *lradc = iio_priv(iio);
1243 iio_trigger_unregister(lradc->trig);
1244 iio_trigger_free(lradc->trig);
1247 static int mxs_lradc_buffer_preenable(struct iio_dev *iio)
1249 struct mxs_lradc *lradc = iio_priv(iio);
1250 int ret = 0, chan, ofs = 0;
1251 unsigned long enable = 0;
1252 uint32_t ctrl4_set = 0;
1253 uint32_t ctrl4_clr = 0;
1254 uint32_t ctrl1_irq = 0;
1255 const uint32_t chan_value = LRADC_CH_ACCUMULATE |
1256 ((LRADC_DELAY_TIMER_LOOP - 1) << LRADC_CH_NUM_SAMPLES_OFFSET);
1257 const int len = bitmap_weight(iio->active_scan_mask,
1258 LRADC_MAX_TOTAL_CHANS);
1264 * Lock the driver so raw access can not be done during buffered
1265 * operation. This simplifies the code a lot.
1267 ret = mutex_trylock(&lradc->lock);
1271 lradc->buffer = kmalloc_array(len, sizeof(*lradc->buffer), GFP_KERNEL);
1272 if (!lradc->buffer) {
1277 if (lradc->soc == IMX28_LRADC)
1278 mxs_lradc_reg_clear(lradc,
1279 lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
1281 mxs_lradc_reg_clear(lradc, lradc->buffer_vchans, LRADC_CTRL0);
1283 for_each_set_bit(chan, iio->active_scan_mask, LRADC_MAX_TOTAL_CHANS) {
1284 ctrl4_set |= chan << LRADC_CTRL4_LRADCSELECT_OFFSET(ofs);
1285 ctrl4_clr |= LRADC_CTRL4_LRADCSELECT_MASK(ofs);
1286 ctrl1_irq |= LRADC_CTRL1_LRADC_IRQ_EN(ofs);
1287 mxs_lradc_reg_wrt(lradc, chan_value, LRADC_CH(ofs));
1288 bitmap_set(&enable, ofs, 1);
1292 mxs_lradc_reg_clear(lradc, LRADC_DELAY_TRIGGER_LRADCS_MASK |
1293 LRADC_DELAY_KICK, LRADC_DELAY(0));
1294 mxs_lradc_reg_clear(lradc, ctrl4_clr, LRADC_CTRL4);
1295 mxs_lradc_reg_set(lradc, ctrl4_set, LRADC_CTRL4);
1296 mxs_lradc_reg_set(lradc, ctrl1_irq, LRADC_CTRL1);
1297 mxs_lradc_reg_set(lradc, enable << LRADC_DELAY_TRIGGER_LRADCS_OFFSET,
1303 mutex_unlock(&lradc->lock);
1307 static int mxs_lradc_buffer_postdisable(struct iio_dev *iio)
1309 struct mxs_lradc *lradc = iio_priv(iio);
1311 mxs_lradc_reg_clear(lradc, LRADC_DELAY_TRIGGER_LRADCS_MASK |
1312 LRADC_DELAY_KICK, LRADC_DELAY(0));
1314 mxs_lradc_reg_clear(lradc, lradc->buffer_vchans, LRADC_CTRL0);
1315 if (lradc->soc == IMX28_LRADC)
1316 mxs_lradc_reg_clear(lradc,
1317 lradc->buffer_vchans << LRADC_CTRL1_LRADC_IRQ_EN_OFFSET,
1320 kfree(lradc->buffer);
1321 mutex_unlock(&lradc->lock);
1326 static bool mxs_lradc_validate_scan_mask(struct iio_dev *iio,
1327 const unsigned long *mask)
1329 struct mxs_lradc *lradc = iio_priv(iio);
1330 const int map_chans = bitmap_weight(mask, LRADC_MAX_TOTAL_CHANS);
1332 unsigned long rsvd_mask = 0;
1334 if (lradc->use_touchbutton)
1335 rsvd_mask |= CHAN_MASK_TOUCHBUTTON;
1336 if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_4WIRE)
1337 rsvd_mask |= CHAN_MASK_TOUCHSCREEN_4WIRE;
1338 if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE)
1339 rsvd_mask |= CHAN_MASK_TOUCHSCREEN_5WIRE;
1341 if (lradc->use_touchbutton)
1343 if (lradc->use_touchscreen)
1346 /* Test for attempts to map channels with special mode of operation. */
1347 if (bitmap_intersects(mask, &rsvd_mask, LRADC_MAX_TOTAL_CHANS))
1350 /* Test for attempts to map more channels then available slots. */
1351 if (map_chans + rsvd_chans > LRADC_MAX_MAPPED_CHANS)
1357 static const struct iio_buffer_setup_ops mxs_lradc_buffer_ops = {
1358 .preenable = &mxs_lradc_buffer_preenable,
1359 .postenable = &iio_triggered_buffer_postenable,
1360 .predisable = &iio_triggered_buffer_predisable,
1361 .postdisable = &mxs_lradc_buffer_postdisable,
1362 .validate_scan_mask = &mxs_lradc_validate_scan_mask,
1366 * Driver initialization
1369 #define MXS_ADC_CHAN(idx, chan_type, name) { \
1370 .type = (chan_type), \
1372 .scan_index = (idx), \
1373 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
1374 BIT(IIO_CHAN_INFO_SCALE), \
1379 .realbits = LRADC_RESOLUTION, \
1380 .storagebits = 32, \
1382 .datasheet_name = (name), \
1385 static const struct iio_chan_spec mx23_lradc_chan_spec[] = {
1386 MXS_ADC_CHAN(0, IIO_VOLTAGE, "LRADC0"),
1387 MXS_ADC_CHAN(1, IIO_VOLTAGE, "LRADC1"),
1388 MXS_ADC_CHAN(2, IIO_VOLTAGE, "LRADC2"),
1389 MXS_ADC_CHAN(3, IIO_VOLTAGE, "LRADC3"),
1390 MXS_ADC_CHAN(4, IIO_VOLTAGE, "LRADC4"),
1391 MXS_ADC_CHAN(5, IIO_VOLTAGE, "LRADC5"),
1392 MXS_ADC_CHAN(6, IIO_VOLTAGE, "VDDIO"),
1393 MXS_ADC_CHAN(7, IIO_VOLTAGE, "VBATT"),
1394 /* Combined Temperature sensors */
1399 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
1400 BIT(IIO_CHAN_INFO_OFFSET) |
1401 BIT(IIO_CHAN_INFO_SCALE),
1403 .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
1404 .datasheet_name = "TEMP_DIE",
1406 /* Hidden channel to keep indexes */
1413 MXS_ADC_CHAN(10, IIO_VOLTAGE, NULL),
1414 MXS_ADC_CHAN(11, IIO_VOLTAGE, NULL),
1415 MXS_ADC_CHAN(12, IIO_VOLTAGE, "USB_DP"),
1416 MXS_ADC_CHAN(13, IIO_VOLTAGE, "USB_DN"),
1417 MXS_ADC_CHAN(14, IIO_VOLTAGE, "VBG"),
1418 MXS_ADC_CHAN(15, IIO_VOLTAGE, "VDD5V"),
1421 static const struct iio_chan_spec mx28_lradc_chan_spec[] = {
1422 MXS_ADC_CHAN(0, IIO_VOLTAGE, "LRADC0"),
1423 MXS_ADC_CHAN(1, IIO_VOLTAGE, "LRADC1"),
1424 MXS_ADC_CHAN(2, IIO_VOLTAGE, "LRADC2"),
1425 MXS_ADC_CHAN(3, IIO_VOLTAGE, "LRADC3"),
1426 MXS_ADC_CHAN(4, IIO_VOLTAGE, "LRADC4"),
1427 MXS_ADC_CHAN(5, IIO_VOLTAGE, "LRADC5"),
1428 MXS_ADC_CHAN(6, IIO_VOLTAGE, "LRADC6"),
1429 MXS_ADC_CHAN(7, IIO_VOLTAGE, "VBATT"),
1430 /* Combined Temperature sensors */
1435 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
1436 BIT(IIO_CHAN_INFO_OFFSET) |
1437 BIT(IIO_CHAN_INFO_SCALE),
1439 .scan_type = {.sign = 'u', .realbits = 18, .storagebits = 32,},
1440 .datasheet_name = "TEMP_DIE",
1442 /* Hidden channel to keep indexes */
1449 MXS_ADC_CHAN(10, IIO_VOLTAGE, "VDDIO"),
1450 MXS_ADC_CHAN(11, IIO_VOLTAGE, "VTH"),
1451 MXS_ADC_CHAN(12, IIO_VOLTAGE, "VDDA"),
1452 MXS_ADC_CHAN(13, IIO_VOLTAGE, "VDDD"),
1453 MXS_ADC_CHAN(14, IIO_VOLTAGE, "VBG"),
1454 MXS_ADC_CHAN(15, IIO_VOLTAGE, "VDD5V"),
1457 static int mxs_lradc_hw_init(struct mxs_lradc *lradc)
1459 /* The ADC always uses DELAY CHANNEL 0. */
1460 const uint32_t adc_cfg =
1461 (1 << (LRADC_DELAY_TRIGGER_DELAYS_OFFSET + 0)) |
1462 (LRADC_DELAY_TIMER_PER << LRADC_DELAY_DELAY_OFFSET);
1464 int ret = stmp_reset_block(lradc->base);
1469 /* Configure DELAY CHANNEL 0 for generic ADC sampling. */
1470 mxs_lradc_reg_wrt(lradc, adc_cfg, LRADC_DELAY(0));
1472 /* Disable remaining DELAY CHANNELs */
1473 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(1));
1474 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(2));
1475 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(3));
1477 /* Configure the touchscreen type */
1478 if (lradc->soc == IMX28_LRADC) {
1479 mxs_lradc_reg_clear(lradc, LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
1482 if (lradc->use_touchscreen == MXS_LRADC_TOUCHSCREEN_5WIRE)
1483 mxs_lradc_reg_set(lradc, LRADC_CTRL0_MX28_TOUCH_SCREEN_TYPE,
1487 /* Start internal temperature sensing. */
1488 mxs_lradc_reg_wrt(lradc, 0, LRADC_CTRL2);
1493 static void mxs_lradc_hw_stop(struct mxs_lradc *lradc)
1497 mxs_lradc_reg_clear(lradc, mxs_lradc_irq_en_mask(lradc), LRADC_CTRL1);
1499 for (i = 0; i < LRADC_MAX_DELAY_CHANS; i++)
1500 mxs_lradc_reg_wrt(lradc, 0, LRADC_DELAY(i));
1503 static const struct of_device_id mxs_lradc_dt_ids[] = {
1504 { .compatible = "fsl,imx23-lradc", .data = (void *)IMX23_LRADC, },
1505 { .compatible = "fsl,imx28-lradc", .data = (void *)IMX28_LRADC, },
1508 MODULE_DEVICE_TABLE(of, mxs_lradc_dt_ids);
1510 static int mxs_lradc_probe_touchscreen(struct mxs_lradc *lradc,
1511 struct device_node *lradc_node)
1514 u32 ts_wires = 0, adapt;
1516 ret = of_property_read_u32(lradc_node, "fsl,lradc-touchscreen-wires",
1519 return -ENODEV; /* touchscreen feature disabled */
1523 lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_4WIRE;
1526 if (lradc->soc == IMX28_LRADC) {
1527 lradc->use_touchscreen = MXS_LRADC_TOUCHSCREEN_5WIRE;
1530 /* fall through an error message for i.MX23 */
1533 "Unsupported number of touchscreen wires (%d)\n",
1538 if (of_property_read_u32(lradc_node, "fsl,ave-ctrl", &adapt)) {
1539 lradc->over_sample_cnt = 4;
1541 if (adapt < 1 || adapt > 32) {
1542 dev_err(lradc->dev, "Invalid sample count (%u)\n",
1546 lradc->over_sample_cnt = adapt;
1549 if (of_property_read_u32(lradc_node, "fsl,ave-delay", &adapt)) {
1550 lradc->over_sample_delay = 2;
1552 if (adapt < 2 || adapt > LRADC_DELAY_DELAY_MASK + 1) {
1553 dev_err(lradc->dev, "Invalid sample delay (%u)\n",
1557 lradc->over_sample_delay = adapt;
1560 if (of_property_read_u32(lradc_node, "fsl,settling", &adapt)) {
1561 lradc->settling_delay = 10;
1563 if (adapt < 1 || adapt > LRADC_DELAY_DELAY_MASK) {
1564 dev_err(lradc->dev, "Invalid settling delay (%u)\n",
1568 lradc->settling_delay = adapt;
1574 static int mxs_lradc_probe(struct platform_device *pdev)
1576 const struct of_device_id *of_id =
1577 of_match_device(mxs_lradc_dt_ids, &pdev->dev);
1578 const struct mxs_lradc_of_config *of_cfg =
1579 &mxs_lradc_of_config[(enum mxs_lradc_id)of_id->data];
1580 struct device *dev = &pdev->dev;
1581 struct device_node *node = dev->of_node;
1582 struct mxs_lradc *lradc;
1583 struct iio_dev *iio;
1584 struct resource *iores;
1585 int ret = 0, touch_ret;
1589 /* Allocate the IIO device. */
1590 iio = devm_iio_device_alloc(dev, sizeof(*lradc));
1592 dev_err(dev, "Failed to allocate IIO device\n");
1596 lradc = iio_priv(iio);
1597 lradc->soc = (enum mxs_lradc_id)of_id->data;
1599 /* Grab the memory area */
1600 iores = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1601 lradc->dev = &pdev->dev;
1602 lradc->base = devm_ioremap_resource(dev, iores);
1603 if (IS_ERR(lradc->base))
1604 return PTR_ERR(lradc->base);
1606 lradc->clk = devm_clk_get(&pdev->dev, NULL);
1607 if (IS_ERR(lradc->clk)) {
1608 dev_err(dev, "Failed to get the delay unit clock\n");
1609 return PTR_ERR(lradc->clk);
1611 ret = clk_prepare_enable(lradc->clk);
1613 dev_err(dev, "Failed to enable the delay unit clock\n");
1617 touch_ret = mxs_lradc_probe_touchscreen(lradc, node);
1620 lradc->buffer_vchans = BUFFER_VCHANS_LIMITED;
1622 lradc->buffer_vchans = BUFFER_VCHANS_ALL;
1624 /* Grab all IRQ sources */
1625 for (i = 0; i < of_cfg->irq_count; i++) {
1626 lradc->irq[i] = platform_get_irq(pdev, i);
1627 if (lradc->irq[i] < 0) {
1628 ret = lradc->irq[i];
1632 ret = devm_request_irq(dev, lradc->irq[i],
1633 mxs_lradc_handle_irq, 0,
1634 of_cfg->irq_name[i], iio);
1639 lradc->vref_mv = of_cfg->vref_mv;
1641 platform_set_drvdata(pdev, iio);
1643 init_completion(&lradc->completion);
1644 mutex_init(&lradc->lock);
1646 iio->name = pdev->name;
1647 iio->dev.parent = &pdev->dev;
1648 iio->info = &mxs_lradc_iio_info;
1649 iio->modes = INDIO_DIRECT_MODE;
1650 iio->masklength = LRADC_MAX_TOTAL_CHANS;
1652 if (lradc->soc == IMX23_LRADC) {
1653 iio->channels = mx23_lradc_chan_spec;
1654 iio->num_channels = ARRAY_SIZE(mx23_lradc_chan_spec);
1656 iio->channels = mx28_lradc_chan_spec;
1657 iio->num_channels = ARRAY_SIZE(mx28_lradc_chan_spec);
1660 ret = iio_triggered_buffer_setup(iio, &iio_pollfunc_store_time,
1661 &mxs_lradc_trigger_handler,
1662 &mxs_lradc_buffer_ops);
1666 ret = mxs_lradc_trigger_init(iio);
1670 /* Populate available ADC input ranges */
1671 for (i = 0; i < LRADC_MAX_TOTAL_CHANS; i++) {
1672 for (s = 0; s < ARRAY_SIZE(lradc->scale_avail[i]); s++) {
1674 * [s=0] = optional divider by two disabled (default)
1675 * [s=1] = optional divider by two enabled
1677 * The scale is calculated by doing:
1678 * Vref >> (realbits - s)
1679 * which multiplies by two on the second component
1682 scale_uv = ((u64)lradc->vref_mv[i] * 100000000) >>
1683 (LRADC_RESOLUTION - s);
1684 lradc->scale_avail[i][s].nano =
1685 do_div(scale_uv, 100000000) * 10;
1686 lradc->scale_avail[i][s].integer = scale_uv;
1690 /* Configure the hardware. */
1691 ret = mxs_lradc_hw_init(lradc);
1695 /* Register the touchscreen input device. */
1696 if (touch_ret == 0) {
1697 ret = mxs_lradc_ts_register(lradc);
1699 goto err_ts_register;
1702 /* Register IIO device. */
1703 ret = iio_device_register(iio);
1705 dev_err(dev, "Failed to register IIO device\n");
1712 mxs_lradc_ts_unregister(lradc);
1714 mxs_lradc_hw_stop(lradc);
1716 mxs_lradc_trigger_remove(iio);
1718 iio_triggered_buffer_cleanup(iio);
1720 clk_disable_unprepare(lradc->clk);
1724 static int mxs_lradc_remove(struct platform_device *pdev)
1726 struct iio_dev *iio = platform_get_drvdata(pdev);
1727 struct mxs_lradc *lradc = iio_priv(iio);
1729 iio_device_unregister(iio);
1730 mxs_lradc_ts_unregister(lradc);
1731 mxs_lradc_hw_stop(lradc);
1732 mxs_lradc_trigger_remove(iio);
1733 iio_triggered_buffer_cleanup(iio);
1735 clk_disable_unprepare(lradc->clk);
1739 static struct platform_driver mxs_lradc_driver = {
1741 .name = DRIVER_NAME,
1742 .of_match_table = mxs_lradc_dt_ids,
1744 .probe = mxs_lradc_probe,
1745 .remove = mxs_lradc_remove,
1748 module_platform_driver(mxs_lradc_driver);
1750 MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
1751 MODULE_DESCRIPTION("Freescale MXS LRADC driver");
1752 MODULE_LICENSE("GPL v2");
1753 MODULE_ALIAS("platform:" DRIVER_NAME);