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Merge remote-tracking branch 'input-current/for-linus'
[deliverable/linux.git] / drivers / iio / adc / at91_adc.c
1 /*
2 * Driver for the ADC present in the Atmel AT91 evaluation boards.
3 *
4 * Copyright 2011 Free Electrons
5 *
6 * Licensed under the GPLv2 or later.
7 */
8
9 #include <linux/bitmap.h>
10 #include <linux/bitops.h>
11 #include <linux/clk.h>
12 #include <linux/err.h>
13 #include <linux/io.h>
14 #include <linux/input.h>
15 #include <linux/interrupt.h>
16 #include <linux/jiffies.h>
17 #include <linux/kernel.h>
18 #include <linux/module.h>
19 #include <linux/of.h>
20 #include <linux/of_device.h>
21 #include <linux/platform_device.h>
22 #include <linux/sched.h>
23 #include <linux/slab.h>
24 #include <linux/wait.h>
25
26 #include <linux/platform_data/at91_adc.h>
27
28 #include <linux/iio/iio.h>
29 #include <linux/iio/buffer.h>
30 #include <linux/iio/trigger.h>
31 #include <linux/iio/trigger_consumer.h>
32 #include <linux/iio/triggered_buffer.h>
33
34 /* Registers */
35 #define AT91_ADC_CR 0x00 /* Control Register */
36 #define AT91_ADC_SWRST (1 << 0) /* Software Reset */
37 #define AT91_ADC_START (1 << 1) /* Start Conversion */
38
39 #define AT91_ADC_MR 0x04 /* Mode Register */
40 #define AT91_ADC_TSAMOD (3 << 0) /* ADC mode */
41 #define AT91_ADC_TSAMOD_ADC_ONLY_MODE (0 << 0) /* ADC Mode */
42 #define AT91_ADC_TSAMOD_TS_ONLY_MODE (1 << 0) /* Touch Screen Only Mode */
43 #define AT91_ADC_TRGEN (1 << 0) /* Trigger Enable */
44 #define AT91_ADC_TRGSEL (7 << 1) /* Trigger Selection */
45 #define AT91_ADC_TRGSEL_TC0 (0 << 1)
46 #define AT91_ADC_TRGSEL_TC1 (1 << 1)
47 #define AT91_ADC_TRGSEL_TC2 (2 << 1)
48 #define AT91_ADC_TRGSEL_EXTERNAL (6 << 1)
49 #define AT91_ADC_LOWRES (1 << 4) /* Low Resolution */
50 #define AT91_ADC_SLEEP (1 << 5) /* Sleep Mode */
51 #define AT91_ADC_PENDET (1 << 6) /* Pen contact detection enable */
52 #define AT91_ADC_PRESCAL_9260 (0x3f << 8) /* Prescalar Rate Selection */
53 #define AT91_ADC_PRESCAL_9G45 (0xff << 8)
54 #define AT91_ADC_PRESCAL_(x) ((x) << 8)
55 #define AT91_ADC_STARTUP_9260 (0x1f << 16) /* Startup Up Time */
56 #define AT91_ADC_STARTUP_9G45 (0x7f << 16)
57 #define AT91_ADC_STARTUP_9X5 (0xf << 16)
58 #define AT91_ADC_STARTUP_(x) ((x) << 16)
59 #define AT91_ADC_SHTIM (0xf << 24) /* Sample & Hold Time */
60 #define AT91_ADC_SHTIM_(x) ((x) << 24)
61 #define AT91_ADC_PENDBC (0x0f << 28) /* Pen Debounce time */
62 #define AT91_ADC_PENDBC_(x) ((x) << 28)
63
64 #define AT91_ADC_TSR 0x0C
65 #define AT91_ADC_TSR_SHTIM (0xf << 24) /* Sample & Hold Time */
66 #define AT91_ADC_TSR_SHTIM_(x) ((x) << 24)
67
68 #define AT91_ADC_CHER 0x10 /* Channel Enable Register */
69 #define AT91_ADC_CHDR 0x14 /* Channel Disable Register */
70 #define AT91_ADC_CHSR 0x18 /* Channel Status Register */
71 #define AT91_ADC_CH(n) (1 << (n)) /* Channel Number */
72
73 #define AT91_ADC_SR 0x1C /* Status Register */
74 #define AT91_ADC_EOC(n) (1 << (n)) /* End of Conversion on Channel N */
75 #define AT91_ADC_OVRE(n) (1 << ((n) + 8))/* Overrun Error on Channel N */
76 #define AT91_ADC_DRDY (1 << 16) /* Data Ready */
77 #define AT91_ADC_GOVRE (1 << 17) /* General Overrun Error */
78 #define AT91_ADC_ENDRX (1 << 18) /* End of RX Buffer */
79 #define AT91_ADC_RXFUFF (1 << 19) /* RX Buffer Full */
80
81 #define AT91_ADC_SR_9X5 0x30 /* Status Register for 9x5 */
82 #define AT91_ADC_SR_DRDY_9X5 (1 << 24) /* Data Ready */
83
84 #define AT91_ADC_LCDR 0x20 /* Last Converted Data Register */
85 #define AT91_ADC_LDATA (0x3ff)
86
87 #define AT91_ADC_IER 0x24 /* Interrupt Enable Register */
88 #define AT91_ADC_IDR 0x28 /* Interrupt Disable Register */
89 #define AT91_ADC_IMR 0x2C /* Interrupt Mask Register */
90 #define AT91RL_ADC_IER_PEN (1 << 20)
91 #define AT91RL_ADC_IER_NOPEN (1 << 21)
92 #define AT91_ADC_IER_PEN (1 << 29)
93 #define AT91_ADC_IER_NOPEN (1 << 30)
94 #define AT91_ADC_IER_XRDY (1 << 20)
95 #define AT91_ADC_IER_YRDY (1 << 21)
96 #define AT91_ADC_IER_PRDY (1 << 22)
97 #define AT91_ADC_ISR_PENS (1 << 31)
98
99 #define AT91_ADC_CHR(n) (0x30 + ((n) * 4)) /* Channel Data Register N */
100 #define AT91_ADC_DATA (0x3ff)
101
102 #define AT91_ADC_CDR0_9X5 (0x50) /* Channel Data Register 0 for 9X5 */
103
104 #define AT91_ADC_ACR 0x94 /* Analog Control Register */
105 #define AT91_ADC_ACR_PENDETSENS (0x3 << 0) /* pull-up resistor */
106
107 #define AT91_ADC_TSMR 0xB0
108 #define AT91_ADC_TSMR_TSMODE (3 << 0) /* Touch Screen Mode */
109 #define AT91_ADC_TSMR_TSMODE_NONE (0 << 0)
110 #define AT91_ADC_TSMR_TSMODE_4WIRE_NO_PRESS (1 << 0)
111 #define AT91_ADC_TSMR_TSMODE_4WIRE_PRESS (2 << 0)
112 #define AT91_ADC_TSMR_TSMODE_5WIRE (3 << 0)
113 #define AT91_ADC_TSMR_TSAV (3 << 4) /* Averages samples */
114 #define AT91_ADC_TSMR_TSAV_(x) ((x) << 4)
115 #define AT91_ADC_TSMR_SCTIM (0x0f << 16) /* Switch closure time */
116 #define AT91_ADC_TSMR_PENDBC (0x0f << 28) /* Pen Debounce time */
117 #define AT91_ADC_TSMR_PENDBC_(x) ((x) << 28)
118 #define AT91_ADC_TSMR_NOTSDMA (1 << 22) /* No Touchscreen DMA */
119 #define AT91_ADC_TSMR_PENDET_DIS (0 << 24) /* Pen contact detection disable */
120 #define AT91_ADC_TSMR_PENDET_ENA (1 << 24) /* Pen contact detection enable */
121
122 #define AT91_ADC_TSXPOSR 0xB4
123 #define AT91_ADC_TSYPOSR 0xB8
124 #define AT91_ADC_TSPRESSR 0xBC
125
126 #define AT91_ADC_TRGR_9260 AT91_ADC_MR
127 #define AT91_ADC_TRGR_9G45 0x08
128 #define AT91_ADC_TRGR_9X5 0xC0
129
130 /* Trigger Register bit field */
131 #define AT91_ADC_TRGR_TRGPER (0xffff << 16)
132 #define AT91_ADC_TRGR_TRGPER_(x) ((x) << 16)
133 #define AT91_ADC_TRGR_TRGMOD (0x7 << 0)
134 #define AT91_ADC_TRGR_NONE (0 << 0)
135 #define AT91_ADC_TRGR_MOD_PERIOD_TRIG (5 << 0)
136
137 #define AT91_ADC_CHAN(st, ch) \
138 (st->registers->channel_base + (ch * 4))
139 #define at91_adc_readl(st, reg) \
140 (readl_relaxed(st->reg_base + reg))
141 #define at91_adc_writel(st, reg, val) \
142 (writel_relaxed(val, st->reg_base + reg))
143
144 #define DRIVER_NAME "at91_adc"
145 #define MAX_POS_BITS 12
146
147 #define TOUCH_SAMPLE_PERIOD_US 2000 /* 2ms */
148 #define TOUCH_PEN_DETECT_DEBOUNCE_US 200
149
150 #define MAX_RLPOS_BITS 10
151 #define TOUCH_SAMPLE_PERIOD_US_RL 10000 /* 10ms, the SoC can't keep up with 2ms */
152 #define TOUCH_SHTIM 0xa
153
154 /**
155 * struct at91_adc_reg_desc - Various informations relative to registers
156 * @channel_base: Base offset for the channel data registers
157 * @drdy_mask: Mask of the DRDY field in the relevant registers
158 (Interruptions registers mostly)
159 * @status_register: Offset of the Interrupt Status Register
160 * @trigger_register: Offset of the Trigger setup register
161 * @mr_prescal_mask: Mask of the PRESCAL field in the adc MR register
162 * @mr_startup_mask: Mask of the STARTUP field in the adc MR register
163 */
164 struct at91_adc_reg_desc {
165 u8 channel_base;
166 u32 drdy_mask;
167 u8 status_register;
168 u8 trigger_register;
169 u32 mr_prescal_mask;
170 u32 mr_startup_mask;
171 };
172
173 struct at91_adc_caps {
174 bool has_ts; /* Support touch screen */
175 bool has_tsmr; /* only at91sam9x5, sama5d3 have TSMR reg */
176 /*
177 * Numbers of sampling data will be averaged. Can be 0~3.
178 * Hardware can average (2 ^ ts_filter_average) sample data.
179 */
180 u8 ts_filter_average;
181 /* Pen Detection input pull-up resistor, can be 0~3 */
182 u8 ts_pen_detect_sensitivity;
183
184 /* startup time calculate function */
185 u32 (*calc_startup_ticks)(u32 startup_time, u32 adc_clk_khz);
186
187 u8 num_channels;
188 struct at91_adc_reg_desc registers;
189 };
190
191 struct at91_adc_state {
192 struct clk *adc_clk;
193 u16 *buffer;
194 unsigned long channels_mask;
195 struct clk *clk;
196 bool done;
197 int irq;
198 u16 last_value;
199 int chnb;
200 struct mutex lock;
201 u8 num_channels;
202 void __iomem *reg_base;
203 struct at91_adc_reg_desc *registers;
204 u32 startup_time;
205 u8 sample_hold_time;
206 bool sleep_mode;
207 struct iio_trigger **trig;
208 struct at91_adc_trigger *trigger_list;
209 u32 trigger_number;
210 bool use_external;
211 u32 vref_mv;
212 u32 res; /* resolution used for convertions */
213 bool low_res; /* the resolution corresponds to the lowest one */
214 wait_queue_head_t wq_data_avail;
215 struct at91_adc_caps *caps;
216
217 /*
218 * Following ADC channels are shared by touchscreen:
219 *
220 * CH0 -- Touch screen XP/UL
221 * CH1 -- Touch screen XM/UR
222 * CH2 -- Touch screen YP/LL
223 * CH3 -- Touch screen YM/Sense
224 * CH4 -- Touch screen LR(5-wire only)
225 *
226 * The bitfields below represents the reserved channel in the
227 * touchscreen mode.
228 */
229 #define CHAN_MASK_TOUCHSCREEN_4WIRE (0xf << 0)
230 #define CHAN_MASK_TOUCHSCREEN_5WIRE (0x1f << 0)
231 enum atmel_adc_ts_type touchscreen_type;
232 struct input_dev *ts_input;
233
234 u16 ts_sample_period_val;
235 u32 ts_pressure_threshold;
236 u16 ts_pendbc;
237
238 bool ts_bufferedmeasure;
239 u32 ts_prev_absx;
240 u32 ts_prev_absy;
241 };
242
243 static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
244 {
245 struct iio_poll_func *pf = p;
246 struct iio_dev *idev = pf->indio_dev;
247 struct at91_adc_state *st = iio_priv(idev);
248 int i, j = 0;
249
250 for (i = 0; i < idev->masklength; i++) {
251 if (!test_bit(i, idev->active_scan_mask))
252 continue;
253 st->buffer[j] = at91_adc_readl(st, AT91_ADC_CHAN(st, i));
254 j++;
255 }
256
257 iio_push_to_buffers_with_timestamp(idev, st->buffer, pf->timestamp);
258
259 iio_trigger_notify_done(idev->trig);
260
261 /* Needed to ACK the DRDY interruption */
262 at91_adc_readl(st, AT91_ADC_LCDR);
263
264 enable_irq(st->irq);
265
266 return IRQ_HANDLED;
267 }
268
269 /* Handler for classic adc channel eoc trigger */
270 static void handle_adc_eoc_trigger(int irq, struct iio_dev *idev)
271 {
272 struct at91_adc_state *st = iio_priv(idev);
273
274 if (iio_buffer_enabled(idev)) {
275 disable_irq_nosync(irq);
276 iio_trigger_poll(idev->trig);
277 } else {
278 st->last_value = at91_adc_readl(st, AT91_ADC_CHAN(st, st->chnb));
279 st->done = true;
280 wake_up_interruptible(&st->wq_data_avail);
281 }
282 }
283
284 static int at91_ts_sample(struct at91_adc_state *st)
285 {
286 unsigned int xscale, yscale, reg, z1, z2;
287 unsigned int x, y, pres, xpos, ypos;
288 unsigned int rxp = 1;
289 unsigned int factor = 1000;
290 struct iio_dev *idev = iio_priv_to_dev(st);
291
292 unsigned int xyz_mask_bits = st->res;
293 unsigned int xyz_mask = (1 << xyz_mask_bits) - 1;
294
295 /* calculate position */
296 /* x position = (x / xscale) * max, max = 2^MAX_POS_BITS - 1 */
297 reg = at91_adc_readl(st, AT91_ADC_TSXPOSR);
298 xpos = reg & xyz_mask;
299 x = (xpos << MAX_POS_BITS) - xpos;
300 xscale = (reg >> 16) & xyz_mask;
301 if (xscale == 0) {
302 dev_err(&idev->dev, "Error: xscale == 0!\n");
303 return -1;
304 }
305 x /= xscale;
306
307 /* y position = (y / yscale) * max, max = 2^MAX_POS_BITS - 1 */
308 reg = at91_adc_readl(st, AT91_ADC_TSYPOSR);
309 ypos = reg & xyz_mask;
310 y = (ypos << MAX_POS_BITS) - ypos;
311 yscale = (reg >> 16) & xyz_mask;
312 if (yscale == 0) {
313 dev_err(&idev->dev, "Error: yscale == 0!\n");
314 return -1;
315 }
316 y /= yscale;
317
318 /* calculate the pressure */
319 reg = at91_adc_readl(st, AT91_ADC_TSPRESSR);
320 z1 = reg & xyz_mask;
321 z2 = (reg >> 16) & xyz_mask;
322
323 if (z1 != 0)
324 pres = rxp * (x * factor / 1024) * (z2 * factor / z1 - factor)
325 / factor;
326 else
327 pres = st->ts_pressure_threshold; /* no pen contacted */
328
329 dev_dbg(&idev->dev, "xpos = %d, xscale = %d, ypos = %d, yscale = %d, z1 = %d, z2 = %d, press = %d\n",
330 xpos, xscale, ypos, yscale, z1, z2, pres);
331
332 if (pres < st->ts_pressure_threshold) {
333 dev_dbg(&idev->dev, "x = %d, y = %d, pressure = %d\n",
334 x, y, pres / factor);
335 input_report_abs(st->ts_input, ABS_X, x);
336 input_report_abs(st->ts_input, ABS_Y, y);
337 input_report_abs(st->ts_input, ABS_PRESSURE, pres);
338 input_report_key(st->ts_input, BTN_TOUCH, 1);
339 input_sync(st->ts_input);
340 } else {
341 dev_dbg(&idev->dev, "pressure too low: not reporting\n");
342 }
343
344 return 0;
345 }
346
347 static irqreturn_t at91_adc_rl_interrupt(int irq, void *private)
348 {
349 struct iio_dev *idev = private;
350 struct at91_adc_state *st = iio_priv(idev);
351 u32 status = at91_adc_readl(st, st->registers->status_register);
352 unsigned int reg;
353
354 status &= at91_adc_readl(st, AT91_ADC_IMR);
355 if (status & GENMASK(st->num_channels - 1, 0))
356 handle_adc_eoc_trigger(irq, idev);
357
358 if (status & AT91RL_ADC_IER_PEN) {
359 /* Disabling pen debounce is required to get a NOPEN irq */
360 reg = at91_adc_readl(st, AT91_ADC_MR);
361 reg &= ~AT91_ADC_PENDBC;
362 at91_adc_writel(st, AT91_ADC_MR, reg);
363
364 at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
365 at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_NOPEN
366 | AT91_ADC_EOC(3));
367 /* Set up period trigger for sampling */
368 at91_adc_writel(st, st->registers->trigger_register,
369 AT91_ADC_TRGR_MOD_PERIOD_TRIG |
370 AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
371 } else if (status & AT91RL_ADC_IER_NOPEN) {
372 reg = at91_adc_readl(st, AT91_ADC_MR);
373 reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
374 at91_adc_writel(st, AT91_ADC_MR, reg);
375 at91_adc_writel(st, st->registers->trigger_register,
376 AT91_ADC_TRGR_NONE);
377
378 at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_NOPEN
379 | AT91_ADC_EOC(3));
380 at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
381 st->ts_bufferedmeasure = false;
382 input_report_key(st->ts_input, BTN_TOUCH, 0);
383 input_sync(st->ts_input);
384 } else if (status & AT91_ADC_EOC(3) && st->ts_input) {
385 /* Conversion finished and we've a touchscreen */
386 if (st->ts_bufferedmeasure) {
387 /*
388 * Last measurement is always discarded, since it can
389 * be erroneous.
390 * Always report previous measurement
391 */
392 input_report_abs(st->ts_input, ABS_X, st->ts_prev_absx);
393 input_report_abs(st->ts_input, ABS_Y, st->ts_prev_absy);
394 input_report_key(st->ts_input, BTN_TOUCH, 1);
395 input_sync(st->ts_input);
396 } else
397 st->ts_bufferedmeasure = true;
398
399 /* Now make new measurement */
400 st->ts_prev_absx = at91_adc_readl(st, AT91_ADC_CHAN(st, 3))
401 << MAX_RLPOS_BITS;
402 st->ts_prev_absx /= at91_adc_readl(st, AT91_ADC_CHAN(st, 2));
403
404 st->ts_prev_absy = at91_adc_readl(st, AT91_ADC_CHAN(st, 1))
405 << MAX_RLPOS_BITS;
406 st->ts_prev_absy /= at91_adc_readl(st, AT91_ADC_CHAN(st, 0));
407 }
408
409 return IRQ_HANDLED;
410 }
411
412 static irqreturn_t at91_adc_9x5_interrupt(int irq, void *private)
413 {
414 struct iio_dev *idev = private;
415 struct at91_adc_state *st = iio_priv(idev);
416 u32 status = at91_adc_readl(st, st->registers->status_register);
417 const uint32_t ts_data_irq_mask =
418 AT91_ADC_IER_XRDY |
419 AT91_ADC_IER_YRDY |
420 AT91_ADC_IER_PRDY;
421
422 if (status & GENMASK(st->num_channels - 1, 0))
423 handle_adc_eoc_trigger(irq, idev);
424
425 if (status & AT91_ADC_IER_PEN) {
426 at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
427 at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_NOPEN |
428 ts_data_irq_mask);
429 /* Set up period trigger for sampling */
430 at91_adc_writel(st, st->registers->trigger_register,
431 AT91_ADC_TRGR_MOD_PERIOD_TRIG |
432 AT91_ADC_TRGR_TRGPER_(st->ts_sample_period_val));
433 } else if (status & AT91_ADC_IER_NOPEN) {
434 at91_adc_writel(st, st->registers->trigger_register, 0);
435 at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_NOPEN |
436 ts_data_irq_mask);
437 at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
438
439 input_report_key(st->ts_input, BTN_TOUCH, 0);
440 input_sync(st->ts_input);
441 } else if ((status & ts_data_irq_mask) == ts_data_irq_mask) {
442 /* Now all touchscreen data is ready */
443
444 if (status & AT91_ADC_ISR_PENS) {
445 /* validate data by pen contact */
446 at91_ts_sample(st);
447 } else {
448 /* triggered by event that is no pen contact, just read
449 * them to clean the interrupt and discard all.
450 */
451 at91_adc_readl(st, AT91_ADC_TSXPOSR);
452 at91_adc_readl(st, AT91_ADC_TSYPOSR);
453 at91_adc_readl(st, AT91_ADC_TSPRESSR);
454 }
455 }
456
457 return IRQ_HANDLED;
458 }
459
460 static int at91_adc_channel_init(struct iio_dev *idev)
461 {
462 struct at91_adc_state *st = iio_priv(idev);
463 struct iio_chan_spec *chan_array, *timestamp;
464 int bit, idx = 0;
465 unsigned long rsvd_mask = 0;
466
467 /* If touchscreen is enable, then reserve the adc channels */
468 if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
469 rsvd_mask = CHAN_MASK_TOUCHSCREEN_4WIRE;
470 else if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_5WIRE)
471 rsvd_mask = CHAN_MASK_TOUCHSCREEN_5WIRE;
472
473 /* set up the channel mask to reserve touchscreen channels */
474 st->channels_mask &= ~rsvd_mask;
475
476 idev->num_channels = bitmap_weight(&st->channels_mask,
477 st->num_channels) + 1;
478
479 chan_array = devm_kzalloc(&idev->dev,
480 ((idev->num_channels + 1) *
481 sizeof(struct iio_chan_spec)),
482 GFP_KERNEL);
483
484 if (!chan_array)
485 return -ENOMEM;
486
487 for_each_set_bit(bit, &st->channels_mask, st->num_channels) {
488 struct iio_chan_spec *chan = chan_array + idx;
489
490 chan->type = IIO_VOLTAGE;
491 chan->indexed = 1;
492 chan->channel = bit;
493 chan->scan_index = idx;
494 chan->scan_type.sign = 'u';
495 chan->scan_type.realbits = st->res;
496 chan->scan_type.storagebits = 16;
497 chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE);
498 chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
499 idx++;
500 }
501 timestamp = chan_array + idx;
502
503 timestamp->type = IIO_TIMESTAMP;
504 timestamp->channel = -1;
505 timestamp->scan_index = idx;
506 timestamp->scan_type.sign = 's';
507 timestamp->scan_type.realbits = 64;
508 timestamp->scan_type.storagebits = 64;
509
510 idev->channels = chan_array;
511 return idev->num_channels;
512 }
513
514 static int at91_adc_get_trigger_value_by_name(struct iio_dev *idev,
515 struct at91_adc_trigger *triggers,
516 const char *trigger_name)
517 {
518 struct at91_adc_state *st = iio_priv(idev);
519 int i;
520
521 for (i = 0; i < st->trigger_number; i++) {
522 char *name = kasprintf(GFP_KERNEL,
523 "%s-dev%d-%s",
524 idev->name,
525 idev->id,
526 triggers[i].name);
527 if (!name)
528 return -ENOMEM;
529
530 if (strcmp(trigger_name, name) == 0) {
531 kfree(name);
532 if (triggers[i].value == 0)
533 return -EINVAL;
534 return triggers[i].value;
535 }
536
537 kfree(name);
538 }
539
540 return -EINVAL;
541 }
542
543 static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
544 {
545 struct iio_dev *idev = iio_trigger_get_drvdata(trig);
546 struct at91_adc_state *st = iio_priv(idev);
547 struct at91_adc_reg_desc *reg = st->registers;
548 u32 status = at91_adc_readl(st, reg->trigger_register);
549 int value;
550 u8 bit;
551
552 value = at91_adc_get_trigger_value_by_name(idev,
553 st->trigger_list,
554 idev->trig->name);
555 if (value < 0)
556 return value;
557
558 if (state) {
559 st->buffer = kmalloc(idev->scan_bytes, GFP_KERNEL);
560 if (st->buffer == NULL)
561 return -ENOMEM;
562
563 at91_adc_writel(st, reg->trigger_register,
564 status | value);
565
566 for_each_set_bit(bit, idev->active_scan_mask,
567 st->num_channels) {
568 struct iio_chan_spec const *chan = idev->channels + bit;
569 at91_adc_writel(st, AT91_ADC_CHER,
570 AT91_ADC_CH(chan->channel));
571 }
572
573 at91_adc_writel(st, AT91_ADC_IER, reg->drdy_mask);
574
575 } else {
576 at91_adc_writel(st, AT91_ADC_IDR, reg->drdy_mask);
577
578 at91_adc_writel(st, reg->trigger_register,
579 status & ~value);
580
581 for_each_set_bit(bit, idev->active_scan_mask,
582 st->num_channels) {
583 struct iio_chan_spec const *chan = idev->channels + bit;
584 at91_adc_writel(st, AT91_ADC_CHDR,
585 AT91_ADC_CH(chan->channel));
586 }
587 kfree(st->buffer);
588 }
589
590 return 0;
591 }
592
593 static const struct iio_trigger_ops at91_adc_trigger_ops = {
594 .owner = THIS_MODULE,
595 .set_trigger_state = &at91_adc_configure_trigger,
596 };
597
598 static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *idev,
599 struct at91_adc_trigger *trigger)
600 {
601 struct iio_trigger *trig;
602 int ret;
603
604 trig = iio_trigger_alloc("%s-dev%d-%s", idev->name,
605 idev->id, trigger->name);
606 if (trig == NULL)
607 return NULL;
608
609 trig->dev.parent = idev->dev.parent;
610 iio_trigger_set_drvdata(trig, idev);
611 trig->ops = &at91_adc_trigger_ops;
612
613 ret = iio_trigger_register(trig);
614 if (ret)
615 return NULL;
616
617 return trig;
618 }
619
620 static int at91_adc_trigger_init(struct iio_dev *idev)
621 {
622 struct at91_adc_state *st = iio_priv(idev);
623 int i, ret;
624
625 st->trig = devm_kzalloc(&idev->dev,
626 st->trigger_number * sizeof(*st->trig),
627 GFP_KERNEL);
628
629 if (st->trig == NULL) {
630 ret = -ENOMEM;
631 goto error_ret;
632 }
633
634 for (i = 0; i < st->trigger_number; i++) {
635 if (st->trigger_list[i].is_external && !(st->use_external))
636 continue;
637
638 st->trig[i] = at91_adc_allocate_trigger(idev,
639 st->trigger_list + i);
640 if (st->trig[i] == NULL) {
641 dev_err(&idev->dev,
642 "Could not allocate trigger %d\n", i);
643 ret = -ENOMEM;
644 goto error_trigger;
645 }
646 }
647
648 return 0;
649
650 error_trigger:
651 for (i--; i >= 0; i--) {
652 iio_trigger_unregister(st->trig[i]);
653 iio_trigger_free(st->trig[i]);
654 }
655 error_ret:
656 return ret;
657 }
658
659 static void at91_adc_trigger_remove(struct iio_dev *idev)
660 {
661 struct at91_adc_state *st = iio_priv(idev);
662 int i;
663
664 for (i = 0; i < st->trigger_number; i++) {
665 iio_trigger_unregister(st->trig[i]);
666 iio_trigger_free(st->trig[i]);
667 }
668 }
669
670 static int at91_adc_buffer_init(struct iio_dev *idev)
671 {
672 return iio_triggered_buffer_setup(idev, &iio_pollfunc_store_time,
673 &at91_adc_trigger_handler, NULL);
674 }
675
676 static void at91_adc_buffer_remove(struct iio_dev *idev)
677 {
678 iio_triggered_buffer_cleanup(idev);
679 }
680
681 static int at91_adc_read_raw(struct iio_dev *idev,
682 struct iio_chan_spec const *chan,
683 int *val, int *val2, long mask)
684 {
685 struct at91_adc_state *st = iio_priv(idev);
686 int ret;
687
688 switch (mask) {
689 case IIO_CHAN_INFO_RAW:
690 mutex_lock(&st->lock);
691
692 st->chnb = chan->channel;
693 at91_adc_writel(st, AT91_ADC_CHER,
694 AT91_ADC_CH(chan->channel));
695 at91_adc_writel(st, AT91_ADC_IER, BIT(chan->channel));
696 at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_START);
697
698 ret = wait_event_interruptible_timeout(st->wq_data_avail,
699 st->done,
700 msecs_to_jiffies(1000));
701 if (ret == 0)
702 ret = -ETIMEDOUT;
703 if (ret < 0) {
704 mutex_unlock(&st->lock);
705 return ret;
706 }
707
708 *val = st->last_value;
709
710 at91_adc_writel(st, AT91_ADC_CHDR,
711 AT91_ADC_CH(chan->channel));
712 at91_adc_writel(st, AT91_ADC_IDR, BIT(chan->channel));
713
714 st->last_value = 0;
715 st->done = false;
716 mutex_unlock(&st->lock);
717 return IIO_VAL_INT;
718
719 case IIO_CHAN_INFO_SCALE:
720 *val = st->vref_mv;
721 *val2 = chan->scan_type.realbits;
722 return IIO_VAL_FRACTIONAL_LOG2;
723 default:
724 break;
725 }
726 return -EINVAL;
727 }
728
729 static int at91_adc_of_get_resolution(struct at91_adc_state *st,
730 struct platform_device *pdev)
731 {
732 struct iio_dev *idev = iio_priv_to_dev(st);
733 struct device_node *np = pdev->dev.of_node;
734 int count, i, ret = 0;
735 char *res_name, *s;
736 u32 *resolutions;
737
738 count = of_property_count_strings(np, "atmel,adc-res-names");
739 if (count < 2) {
740 dev_err(&idev->dev, "You must specified at least two resolution names for "
741 "adc-res-names property in the DT\n");
742 return count;
743 }
744
745 resolutions = kmalloc_array(count, sizeof(*resolutions), GFP_KERNEL);
746 if (!resolutions)
747 return -ENOMEM;
748
749 if (of_property_read_u32_array(np, "atmel,adc-res", resolutions, count)) {
750 dev_err(&idev->dev, "Missing adc-res property in the DT.\n");
751 ret = -ENODEV;
752 goto ret;
753 }
754
755 if (of_property_read_string(np, "atmel,adc-use-res", (const char **)&res_name))
756 res_name = "highres";
757
758 for (i = 0; i < count; i++) {
759 if (of_property_read_string_index(np, "atmel,adc-res-names", i, (const char **)&s))
760 continue;
761
762 if (strcmp(res_name, s))
763 continue;
764
765 st->res = resolutions[i];
766 if (!strcmp(res_name, "lowres"))
767 st->low_res = true;
768 else
769 st->low_res = false;
770
771 dev_info(&idev->dev, "Resolution used: %u bits\n", st->res);
772 goto ret;
773 }
774
775 dev_err(&idev->dev, "There is no resolution for %s\n", res_name);
776
777 ret:
778 kfree(resolutions);
779 return ret;
780 }
781
782 static u32 calc_startup_ticks_9260(u32 startup_time, u32 adc_clk_khz)
783 {
784 /*
785 * Number of ticks needed to cover the startup time of the ADC
786 * as defined in the electrical characteristics of the board,
787 * divided by 8. The formula thus is :
788 * Startup Time = (ticks + 1) * 8 / ADC Clock
789 */
790 return round_up((startup_time * adc_clk_khz / 1000) - 1, 8) / 8;
791 }
792
793 static u32 calc_startup_ticks_9x5(u32 startup_time, u32 adc_clk_khz)
794 {
795 /*
796 * For sama5d3x and at91sam9x5, the formula changes to:
797 * Startup Time = <lookup_table_value> / ADC Clock
798 */
799 const int startup_lookup[] = {
800 0, 8, 16, 24,
801 64, 80, 96, 112,
802 512, 576, 640, 704,
803 768, 832, 896, 960
804 };
805 int i, size = ARRAY_SIZE(startup_lookup);
806 unsigned int ticks;
807
808 ticks = startup_time * adc_clk_khz / 1000;
809 for (i = 0; i < size; i++)
810 if (ticks < startup_lookup[i])
811 break;
812
813 ticks = i;
814 if (ticks == size)
815 /* Reach the end of lookup table */
816 ticks = size - 1;
817
818 return ticks;
819 }
820
821 static const struct of_device_id at91_adc_dt_ids[];
822
823 static int at91_adc_probe_dt_ts(struct device_node *node,
824 struct at91_adc_state *st, struct device *dev)
825 {
826 int ret;
827 u32 prop;
828
829 ret = of_property_read_u32(node, "atmel,adc-ts-wires", &prop);
830 if (ret) {
831 dev_info(dev, "ADC Touch screen is disabled.\n");
832 return 0;
833 }
834
835 switch (prop) {
836 case 4:
837 case 5:
838 st->touchscreen_type = prop;
839 break;
840 default:
841 dev_err(dev, "Unsupported number of touchscreen wires (%d). Should be 4 or 5.\n", prop);
842 return -EINVAL;
843 }
844
845 if (!st->caps->has_tsmr)
846 return 0;
847 prop = 0;
848 of_property_read_u32(node, "atmel,adc-ts-pressure-threshold", &prop);
849 st->ts_pressure_threshold = prop;
850 if (st->ts_pressure_threshold) {
851 return 0;
852 } else {
853 dev_err(dev, "Invalid pressure threshold for the touchscreen\n");
854 return -EINVAL;
855 }
856 }
857
858 static int at91_adc_probe_dt(struct at91_adc_state *st,
859 struct platform_device *pdev)
860 {
861 struct iio_dev *idev = iio_priv_to_dev(st);
862 struct device_node *node = pdev->dev.of_node;
863 struct device_node *trig_node;
864 int i = 0, ret;
865 u32 prop;
866
867 if (!node)
868 return -EINVAL;
869
870 st->caps = (struct at91_adc_caps *)
871 of_match_device(at91_adc_dt_ids, &pdev->dev)->data;
872
873 st->use_external = of_property_read_bool(node, "atmel,adc-use-external-triggers");
874
875 if (of_property_read_u32(node, "atmel,adc-channels-used", &prop)) {
876 dev_err(&idev->dev, "Missing adc-channels-used property in the DT.\n");
877 ret = -EINVAL;
878 goto error_ret;
879 }
880 st->channels_mask = prop;
881
882 st->sleep_mode = of_property_read_bool(node, "atmel,adc-sleep-mode");
883
884 if (of_property_read_u32(node, "atmel,adc-startup-time", &prop)) {
885 dev_err(&idev->dev, "Missing adc-startup-time property in the DT.\n");
886 ret = -EINVAL;
887 goto error_ret;
888 }
889 st->startup_time = prop;
890
891 prop = 0;
892 of_property_read_u32(node, "atmel,adc-sample-hold-time", &prop);
893 st->sample_hold_time = prop;
894
895 if (of_property_read_u32(node, "atmel,adc-vref", &prop)) {
896 dev_err(&idev->dev, "Missing adc-vref property in the DT.\n");
897 ret = -EINVAL;
898 goto error_ret;
899 }
900 st->vref_mv = prop;
901
902 ret = at91_adc_of_get_resolution(st, pdev);
903 if (ret)
904 goto error_ret;
905
906 st->registers = &st->caps->registers;
907 st->num_channels = st->caps->num_channels;
908 st->trigger_number = of_get_child_count(node);
909 st->trigger_list = devm_kzalloc(&idev->dev, st->trigger_number *
910 sizeof(struct at91_adc_trigger),
911 GFP_KERNEL);
912 if (!st->trigger_list) {
913 dev_err(&idev->dev, "Could not allocate trigger list memory.\n");
914 ret = -ENOMEM;
915 goto error_ret;
916 }
917
918 for_each_child_of_node(node, trig_node) {
919 struct at91_adc_trigger *trig = st->trigger_list + i;
920 const char *name;
921
922 if (of_property_read_string(trig_node, "trigger-name", &name)) {
923 dev_err(&idev->dev, "Missing trigger-name property in the DT.\n");
924 ret = -EINVAL;
925 goto error_ret;
926 }
927 trig->name = name;
928
929 if (of_property_read_u32(trig_node, "trigger-value", &prop)) {
930 dev_err(&idev->dev, "Missing trigger-value property in the DT.\n");
931 ret = -EINVAL;
932 goto error_ret;
933 }
934 trig->value = prop;
935 trig->is_external = of_property_read_bool(trig_node, "trigger-external");
936 i++;
937 }
938
939 /* Check if touchscreen is supported. */
940 if (st->caps->has_ts)
941 return at91_adc_probe_dt_ts(node, st, &idev->dev);
942 else
943 dev_info(&idev->dev, "not support touchscreen in the adc compatible string.\n");
944
945 return 0;
946
947 error_ret:
948 return ret;
949 }
950
951 static int at91_adc_probe_pdata(struct at91_adc_state *st,
952 struct platform_device *pdev)
953 {
954 struct at91_adc_data *pdata = pdev->dev.platform_data;
955
956 if (!pdata)
957 return -EINVAL;
958
959 st->caps = (struct at91_adc_caps *)
960 platform_get_device_id(pdev)->driver_data;
961
962 st->use_external = pdata->use_external_triggers;
963 st->vref_mv = pdata->vref;
964 st->channels_mask = pdata->channels_used;
965 st->num_channels = st->caps->num_channels;
966 st->startup_time = pdata->startup_time;
967 st->trigger_number = pdata->trigger_number;
968 st->trigger_list = pdata->trigger_list;
969 st->registers = &st->caps->registers;
970 st->touchscreen_type = pdata->touchscreen_type;
971
972 return 0;
973 }
974
975 static const struct iio_info at91_adc_info = {
976 .driver_module = THIS_MODULE,
977 .read_raw = &at91_adc_read_raw,
978 };
979
980 /* Touchscreen related functions */
981 static int atmel_ts_open(struct input_dev *dev)
982 {
983 struct at91_adc_state *st = input_get_drvdata(dev);
984
985 if (st->caps->has_tsmr)
986 at91_adc_writel(st, AT91_ADC_IER, AT91_ADC_IER_PEN);
987 else
988 at91_adc_writel(st, AT91_ADC_IER, AT91RL_ADC_IER_PEN);
989 return 0;
990 }
991
992 static void atmel_ts_close(struct input_dev *dev)
993 {
994 struct at91_adc_state *st = input_get_drvdata(dev);
995
996 if (st->caps->has_tsmr)
997 at91_adc_writel(st, AT91_ADC_IDR, AT91_ADC_IER_PEN);
998 else
999 at91_adc_writel(st, AT91_ADC_IDR, AT91RL_ADC_IER_PEN);
1000 }
1001
1002 static int at91_ts_hw_init(struct at91_adc_state *st, u32 adc_clk_khz)
1003 {
1004 u32 reg = 0;
1005 int i = 0;
1006
1007 /* a Pen Detect Debounce Time is necessary for the ADC Touch to avoid
1008 * pen detect noise.
1009 * The formula is : Pen Detect Debounce Time = (2 ^ pendbc) / ADCClock
1010 */
1011 st->ts_pendbc = round_up(TOUCH_PEN_DETECT_DEBOUNCE_US * adc_clk_khz /
1012 1000, 1);
1013
1014 while (st->ts_pendbc >> ++i)
1015 ; /* Empty! Find the shift offset */
1016 if (abs(st->ts_pendbc - (1 << i)) < abs(st->ts_pendbc - (1 << (i - 1))))
1017 st->ts_pendbc = i;
1018 else
1019 st->ts_pendbc = i - 1;
1020
1021 if (!st->caps->has_tsmr) {
1022 reg = at91_adc_readl(st, AT91_ADC_MR);
1023 reg |= AT91_ADC_TSAMOD_TS_ONLY_MODE | AT91_ADC_PENDET;
1024
1025 reg |= AT91_ADC_PENDBC_(st->ts_pendbc) & AT91_ADC_PENDBC;
1026 at91_adc_writel(st, AT91_ADC_MR, reg);
1027
1028 reg = AT91_ADC_TSR_SHTIM_(TOUCH_SHTIM) & AT91_ADC_TSR_SHTIM;
1029 at91_adc_writel(st, AT91_ADC_TSR, reg);
1030
1031 st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US_RL *
1032 adc_clk_khz / 1000) - 1, 1);
1033
1034 return 0;
1035 }
1036
1037 if (st->touchscreen_type == ATMEL_ADC_TOUCHSCREEN_4WIRE)
1038 reg = AT91_ADC_TSMR_TSMODE_4WIRE_PRESS;
1039 else
1040 reg = AT91_ADC_TSMR_TSMODE_5WIRE;
1041
1042 reg |= AT91_ADC_TSMR_TSAV_(st->caps->ts_filter_average)
1043 & AT91_ADC_TSMR_TSAV;
1044 reg |= AT91_ADC_TSMR_PENDBC_(st->ts_pendbc) & AT91_ADC_TSMR_PENDBC;
1045 reg |= AT91_ADC_TSMR_NOTSDMA;
1046 reg |= AT91_ADC_TSMR_PENDET_ENA;
1047 reg |= 0x03 << 8; /* TSFREQ, needs to be bigger than TSAV */
1048
1049 at91_adc_writel(st, AT91_ADC_TSMR, reg);
1050
1051 /* Change adc internal resistor value for better pen detection,
1052 * default value is 100 kOhm.
1053 * 0 = 200 kOhm, 1 = 150 kOhm, 2 = 100 kOhm, 3 = 50 kOhm
1054 * option only available on ES2 and higher
1055 */
1056 at91_adc_writel(st, AT91_ADC_ACR, st->caps->ts_pen_detect_sensitivity
1057 & AT91_ADC_ACR_PENDETSENS);
1058
1059 /* Sample Period Time = (TRGPER + 1) / ADCClock */
1060 st->ts_sample_period_val = round_up((TOUCH_SAMPLE_PERIOD_US *
1061 adc_clk_khz / 1000) - 1, 1);
1062
1063 return 0;
1064 }
1065
1066 static int at91_ts_register(struct at91_adc_state *st,
1067 struct platform_device *pdev)
1068 {
1069 struct input_dev *input;
1070 struct iio_dev *idev = iio_priv_to_dev(st);
1071 int ret;
1072
1073 input = input_allocate_device();
1074 if (!input) {
1075 dev_err(&idev->dev, "Failed to allocate TS device!\n");
1076 return -ENOMEM;
1077 }
1078
1079 input->name = DRIVER_NAME;
1080 input->id.bustype = BUS_HOST;
1081 input->dev.parent = &pdev->dev;
1082 input->open = atmel_ts_open;
1083 input->close = atmel_ts_close;
1084
1085 __set_bit(EV_ABS, input->evbit);
1086 __set_bit(EV_KEY, input->evbit);
1087 __set_bit(BTN_TOUCH, input->keybit);
1088 if (st->caps->has_tsmr) {
1089 input_set_abs_params(input, ABS_X, 0, (1 << MAX_POS_BITS) - 1,
1090 0, 0);
1091 input_set_abs_params(input, ABS_Y, 0, (1 << MAX_POS_BITS) - 1,
1092 0, 0);
1093 input_set_abs_params(input, ABS_PRESSURE, 0, 0xffffff, 0, 0);
1094 } else {
1095 if (st->touchscreen_type != ATMEL_ADC_TOUCHSCREEN_4WIRE) {
1096 dev_err(&pdev->dev,
1097 "This touchscreen controller only support 4 wires\n");
1098 ret = -EINVAL;
1099 goto err;
1100 }
1101
1102 input_set_abs_params(input, ABS_X, 0, (1 << MAX_RLPOS_BITS) - 1,
1103 0, 0);
1104 input_set_abs_params(input, ABS_Y, 0, (1 << MAX_RLPOS_BITS) - 1,
1105 0, 0);
1106 }
1107
1108 st->ts_input = input;
1109 input_set_drvdata(input, st);
1110
1111 ret = input_register_device(input);
1112 if (ret)
1113 goto err;
1114
1115 return ret;
1116
1117 err:
1118 input_free_device(st->ts_input);
1119 return ret;
1120 }
1121
1122 static void at91_ts_unregister(struct at91_adc_state *st)
1123 {
1124 input_unregister_device(st->ts_input);
1125 }
1126
1127 static int at91_adc_probe(struct platform_device *pdev)
1128 {
1129 unsigned int prsc, mstrclk, ticks, adc_clk, adc_clk_khz, shtim;
1130 int ret;
1131 struct iio_dev *idev;
1132 struct at91_adc_state *st;
1133 struct resource *res;
1134 u32 reg;
1135
1136 idev = devm_iio_device_alloc(&pdev->dev, sizeof(struct at91_adc_state));
1137 if (!idev)
1138 return -ENOMEM;
1139
1140 st = iio_priv(idev);
1141
1142 if (pdev->dev.of_node)
1143 ret = at91_adc_probe_dt(st, pdev);
1144 else
1145 ret = at91_adc_probe_pdata(st, pdev);
1146
1147 if (ret) {
1148 dev_err(&pdev->dev, "No platform data available.\n");
1149 return -EINVAL;
1150 }
1151
1152 platform_set_drvdata(pdev, idev);
1153
1154 idev->dev.parent = &pdev->dev;
1155 idev->name = dev_name(&pdev->dev);
1156 idev->modes = INDIO_DIRECT_MODE;
1157 idev->info = &at91_adc_info;
1158
1159 st->irq = platform_get_irq(pdev, 0);
1160 if (st->irq < 0) {
1161 dev_err(&pdev->dev, "No IRQ ID is designated\n");
1162 return -ENODEV;
1163 }
1164
1165 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
1166
1167 st->reg_base = devm_ioremap_resource(&pdev->dev, res);
1168 if (IS_ERR(st->reg_base)) {
1169 return PTR_ERR(st->reg_base);
1170 }
1171
1172 /*
1173 * Disable all IRQs before setting up the handler
1174 */
1175 at91_adc_writel(st, AT91_ADC_CR, AT91_ADC_SWRST);
1176 at91_adc_writel(st, AT91_ADC_IDR, 0xFFFFFFFF);
1177
1178 if (st->caps->has_tsmr)
1179 ret = request_irq(st->irq, at91_adc_9x5_interrupt, 0,
1180 pdev->dev.driver->name, idev);
1181 else
1182 ret = request_irq(st->irq, at91_adc_rl_interrupt, 0,
1183 pdev->dev.driver->name, idev);
1184 if (ret) {
1185 dev_err(&pdev->dev, "Failed to allocate IRQ.\n");
1186 return ret;
1187 }
1188
1189 st->clk = devm_clk_get(&pdev->dev, "adc_clk");
1190 if (IS_ERR(st->clk)) {
1191 dev_err(&pdev->dev, "Failed to get the clock.\n");
1192 ret = PTR_ERR(st->clk);
1193 goto error_free_irq;
1194 }
1195
1196 ret = clk_prepare_enable(st->clk);
1197 if (ret) {
1198 dev_err(&pdev->dev,
1199 "Could not prepare or enable the clock.\n");
1200 goto error_free_irq;
1201 }
1202
1203 st->adc_clk = devm_clk_get(&pdev->dev, "adc_op_clk");
1204 if (IS_ERR(st->adc_clk)) {
1205 dev_err(&pdev->dev, "Failed to get the ADC clock.\n");
1206 ret = PTR_ERR(st->adc_clk);
1207 goto error_disable_clk;
1208 }
1209
1210 ret = clk_prepare_enable(st->adc_clk);
1211 if (ret) {
1212 dev_err(&pdev->dev,
1213 "Could not prepare or enable the ADC clock.\n");
1214 goto error_disable_clk;
1215 }
1216
1217 /*
1218 * Prescaler rate computation using the formula from the Atmel's
1219 * datasheet : ADC Clock = MCK / ((Prescaler + 1) * 2), ADC Clock being
1220 * specified by the electrical characteristics of the board.
1221 */
1222 mstrclk = clk_get_rate(st->clk);
1223 adc_clk = clk_get_rate(st->adc_clk);
1224 adc_clk_khz = adc_clk / 1000;
1225
1226 dev_dbg(&pdev->dev, "Master clock is set as: %d Hz, adc_clk should set as: %d Hz\n",
1227 mstrclk, adc_clk);
1228
1229 prsc = (mstrclk / (2 * adc_clk)) - 1;
1230
1231 if (!st->startup_time) {
1232 dev_err(&pdev->dev, "No startup time available.\n");
1233 ret = -EINVAL;
1234 goto error_disable_adc_clk;
1235 }
1236 ticks = (*st->caps->calc_startup_ticks)(st->startup_time, adc_clk_khz);
1237
1238 /*
1239 * a minimal Sample and Hold Time is necessary for the ADC to guarantee
1240 * the best converted final value between two channels selection
1241 * The formula thus is : Sample and Hold Time = (shtim + 1) / ADCClock
1242 */
1243 if (st->sample_hold_time > 0)
1244 shtim = round_up((st->sample_hold_time * adc_clk_khz / 1000)
1245 - 1, 1);
1246 else
1247 shtim = 0;
1248
1249 reg = AT91_ADC_PRESCAL_(prsc) & st->registers->mr_prescal_mask;
1250 reg |= AT91_ADC_STARTUP_(ticks) & st->registers->mr_startup_mask;
1251 if (st->low_res)
1252 reg |= AT91_ADC_LOWRES;
1253 if (st->sleep_mode)
1254 reg |= AT91_ADC_SLEEP;
1255 reg |= AT91_ADC_SHTIM_(shtim) & AT91_ADC_SHTIM;
1256 at91_adc_writel(st, AT91_ADC_MR, reg);
1257
1258 /* Setup the ADC channels available on the board */
1259 ret = at91_adc_channel_init(idev);
1260 if (ret < 0) {
1261 dev_err(&pdev->dev, "Couldn't initialize the channels.\n");
1262 goto error_disable_adc_clk;
1263 }
1264
1265 init_waitqueue_head(&st->wq_data_avail);
1266 mutex_init(&st->lock);
1267
1268 /*
1269 * Since touch screen will set trigger register as period trigger. So
1270 * when touch screen is enabled, then we have to disable hardware
1271 * trigger for classic adc.
1272 */
1273 if (!st->touchscreen_type) {
1274 ret = at91_adc_buffer_init(idev);
1275 if (ret < 0) {
1276 dev_err(&pdev->dev, "Couldn't initialize the buffer.\n");
1277 goto error_disable_adc_clk;
1278 }
1279
1280 ret = at91_adc_trigger_init(idev);
1281 if (ret < 0) {
1282 dev_err(&pdev->dev, "Couldn't setup the triggers.\n");
1283 at91_adc_buffer_remove(idev);
1284 goto error_disable_adc_clk;
1285 }
1286 } else {
1287 ret = at91_ts_register(st, pdev);
1288 if (ret)
1289 goto error_disable_adc_clk;
1290
1291 at91_ts_hw_init(st, adc_clk_khz);
1292 }
1293
1294 ret = iio_device_register(idev);
1295 if (ret < 0) {
1296 dev_err(&pdev->dev, "Couldn't register the device.\n");
1297 goto error_iio_device_register;
1298 }
1299
1300 return 0;
1301
1302 error_iio_device_register:
1303 if (!st->touchscreen_type) {
1304 at91_adc_trigger_remove(idev);
1305 at91_adc_buffer_remove(idev);
1306 } else {
1307 at91_ts_unregister(st);
1308 }
1309 error_disable_adc_clk:
1310 clk_disable_unprepare(st->adc_clk);
1311 error_disable_clk:
1312 clk_disable_unprepare(st->clk);
1313 error_free_irq:
1314 free_irq(st->irq, idev);
1315 return ret;
1316 }
1317
1318 static int at91_adc_remove(struct platform_device *pdev)
1319 {
1320 struct iio_dev *idev = platform_get_drvdata(pdev);
1321 struct at91_adc_state *st = iio_priv(idev);
1322
1323 iio_device_unregister(idev);
1324 if (!st->touchscreen_type) {
1325 at91_adc_trigger_remove(idev);
1326 at91_adc_buffer_remove(idev);
1327 } else {
1328 at91_ts_unregister(st);
1329 }
1330 clk_disable_unprepare(st->adc_clk);
1331 clk_disable_unprepare(st->clk);
1332 free_irq(st->irq, idev);
1333
1334 return 0;
1335 }
1336
1337 static struct at91_adc_caps at91sam9260_caps = {
1338 .calc_startup_ticks = calc_startup_ticks_9260,
1339 .num_channels = 4,
1340 .registers = {
1341 .channel_base = AT91_ADC_CHR(0),
1342 .drdy_mask = AT91_ADC_DRDY,
1343 .status_register = AT91_ADC_SR,
1344 .trigger_register = AT91_ADC_TRGR_9260,
1345 .mr_prescal_mask = AT91_ADC_PRESCAL_9260,
1346 .mr_startup_mask = AT91_ADC_STARTUP_9260,
1347 },
1348 };
1349
1350 static struct at91_adc_caps at91sam9rl_caps = {
1351 .has_ts = true,
1352 .calc_startup_ticks = calc_startup_ticks_9260, /* same as 9260 */
1353 .num_channels = 6,
1354 .registers = {
1355 .channel_base = AT91_ADC_CHR(0),
1356 .drdy_mask = AT91_ADC_DRDY,
1357 .status_register = AT91_ADC_SR,
1358 .trigger_register = AT91_ADC_TRGR_9G45,
1359 .mr_prescal_mask = AT91_ADC_PRESCAL_9260,
1360 .mr_startup_mask = AT91_ADC_STARTUP_9G45,
1361 },
1362 };
1363
1364 static struct at91_adc_caps at91sam9g45_caps = {
1365 .has_ts = true,
1366 .calc_startup_ticks = calc_startup_ticks_9260, /* same as 9260 */
1367 .num_channels = 8,
1368 .registers = {
1369 .channel_base = AT91_ADC_CHR(0),
1370 .drdy_mask = AT91_ADC_DRDY,
1371 .status_register = AT91_ADC_SR,
1372 .trigger_register = AT91_ADC_TRGR_9G45,
1373 .mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1374 .mr_startup_mask = AT91_ADC_STARTUP_9G45,
1375 },
1376 };
1377
1378 static struct at91_adc_caps at91sam9x5_caps = {
1379 .has_ts = true,
1380 .has_tsmr = true,
1381 .ts_filter_average = 3,
1382 .ts_pen_detect_sensitivity = 2,
1383 .calc_startup_ticks = calc_startup_ticks_9x5,
1384 .num_channels = 12,
1385 .registers = {
1386 .channel_base = AT91_ADC_CDR0_9X5,
1387 .drdy_mask = AT91_ADC_SR_DRDY_9X5,
1388 .status_register = AT91_ADC_SR_9X5,
1389 .trigger_register = AT91_ADC_TRGR_9X5,
1390 /* prescal mask is same as 9G45 */
1391 .mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
1392 .mr_startup_mask = AT91_ADC_STARTUP_9X5,
1393 },
1394 };
1395
1396 static const struct of_device_id at91_adc_dt_ids[] = {
1397 { .compatible = "atmel,at91sam9260-adc", .data = &at91sam9260_caps },
1398 { .compatible = "atmel,at91sam9rl-adc", .data = &at91sam9rl_caps },
1399 { .compatible = "atmel,at91sam9g45-adc", .data = &at91sam9g45_caps },
1400 { .compatible = "atmel,at91sam9x5-adc", .data = &at91sam9x5_caps },
1401 {},
1402 };
1403 MODULE_DEVICE_TABLE(of, at91_adc_dt_ids);
1404
1405 static const struct platform_device_id at91_adc_ids[] = {
1406 {
1407 .name = "at91sam9260-adc",
1408 .driver_data = (unsigned long)&at91sam9260_caps,
1409 }, {
1410 .name = "at91sam9rl-adc",
1411 .driver_data = (unsigned long)&at91sam9rl_caps,
1412 }, {
1413 .name = "at91sam9g45-adc",
1414 .driver_data = (unsigned long)&at91sam9g45_caps,
1415 }, {
1416 .name = "at91sam9x5-adc",
1417 .driver_data = (unsigned long)&at91sam9x5_caps,
1418 }, {
1419 /* terminator */
1420 }
1421 };
1422 MODULE_DEVICE_TABLE(platform, at91_adc_ids);
1423
1424 static struct platform_driver at91_adc_driver = {
1425 .probe = at91_adc_probe,
1426 .remove = at91_adc_remove,
1427 .id_table = at91_adc_ids,
1428 .driver = {
1429 .name = DRIVER_NAME,
1430 .of_match_table = of_match_ptr(at91_adc_dt_ids),
1431 },
1432 };
1433
1434 module_platform_driver(at91_adc_driver);
1435
1436 MODULE_LICENSE("GPL");
1437 MODULE_DESCRIPTION("Atmel AT91 ADC Driver");
1438 MODULE_AUTHOR("Maxime Ripard <maxime.ripard@free-electrons.com>");
Linux kernel - Deliverables
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