1 /*
2 * TI ADC MFD driver
3 *
4 * Copyright (C) 2012 Texas Instruments Incorporated - https://www.ti.com/
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License as
8 * published by the Free Software Foundation version 2.
9 *
10 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
11 * kind, whether express or implied; without even the implied warranty
12 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 */
15
16 #include <linux/kernel.h>
17 #include <linux/err.h>
18 #include <linux/module.h>
19 #include <linux/slab.h>
20 #include <linux/interrupt.h>
21 #include <linux/platform_device.h>
22 #include <linux/io.h>
23 #include <linux/iio/iio.h>
24 #include <linux/of.h>
25 #include <linux/of_device.h>
26 #include <linux/iio/machine.h>
27 #include <linux/iio/driver.h>
28
29 #include <linux/mfd/ti_am335x_tscadc.h>
30 #include <linux/iio/buffer.h>
31 #include <linux/iio/kfifo_buf.h>
32
33 #include <linux/dmaengine.h>
34 #include <linux/dma-mapping.h>
35
36 #define DMA_BUFFER_SIZE SZ_2K
37
38 struct tiadc_dma {
39 struct dma_slave_config conf;
40 struct dma_chan *chan;
41 dma_addr_t addr;
42 dma_cookie_t cookie;
43 u8 *buf;
44 int current_period;
45 int period_size;
46 u8 fifo_thresh;
47 };
48
49 struct tiadc_device {
50 struct ti_tscadc_dev *mfd_tscadc;
51 struct tiadc_dma dma;
52 struct mutex fifo1_lock; /* to protect fifo access */
53 int channels;
54 int total_ch_enabled;
55 u8 channel_line[8];
56 u8 channel_step[8];
57 int buffer_en_ch_steps;
58 u16 data[8];
59 u32 open_delay[8], sample_delay[8], step_avg[8];
60 };
61
tiadc_readl(struct tiadc_device * adc,unsigned int reg)62 static unsigned int tiadc_readl(struct tiadc_device *adc, unsigned int reg)
63 {
64 return readl(adc->mfd_tscadc->tscadc_base + reg);
65 }
66
tiadc_writel(struct tiadc_device * adc,unsigned int reg,unsigned int val)67 static void tiadc_writel(struct tiadc_device *adc, unsigned int reg,
68 unsigned int val)
69 {
70 writel(val, adc->mfd_tscadc->tscadc_base + reg);
71 }
72
get_adc_step_mask(struct tiadc_device * adc_dev)73 static u32 get_adc_step_mask(struct tiadc_device *adc_dev)
74 {
75 u32 step_en;
76
77 step_en = ((1 << adc_dev->channels) - 1);
78 step_en <<= TOTAL_STEPS - adc_dev->channels + 1;
79 return step_en;
80 }
81
get_adc_chan_step_mask(struct tiadc_device * adc_dev,struct iio_chan_spec const * chan)82 static u32 get_adc_chan_step_mask(struct tiadc_device *adc_dev,
83 struct iio_chan_spec const *chan)
84 {
85 int i;
86
87 for (i = 0; i < ARRAY_SIZE(adc_dev->channel_step); i++) {
88 if (chan->channel == adc_dev->channel_line[i]) {
89 u32 step;
90
91 step = adc_dev->channel_step[i];
92 /* +1 for the charger */
93 return 1 << (step + 1);
94 }
95 }
96 WARN_ON(1);
97 return 0;
98 }
99
get_adc_step_bit(struct tiadc_device * adc_dev,int chan)100 static u32 get_adc_step_bit(struct tiadc_device *adc_dev, int chan)
101 {
102 return 1 << adc_dev->channel_step[chan];
103 }
104
tiadc_step_config(struct iio_dev * indio_dev)105 static void tiadc_step_config(struct iio_dev *indio_dev)
106 {
107 struct tiadc_device *adc_dev = iio_priv(indio_dev);
108 struct device *dev = adc_dev->mfd_tscadc->dev;
109 unsigned int stepconfig;
110 int i, steps = 0;
111
112 /*
113 * There are 16 configurable steps and 8 analog input
114 * lines available which are shared between Touchscreen and ADC.
115 *
116 * Steps forwards i.e. from 0 towards 16 are used by ADC
117 * depending on number of input lines needed.
118 * Channel would represent which analog input
119 * needs to be given to ADC to digitalize data.
120 */
121
122
123 for (i = 0; i < adc_dev->channels; i++) {
124 int chan;
125
126 chan = adc_dev->channel_line[i];
127
128 if (adc_dev->step_avg[i] > STEPCONFIG_AVG_16) {
129 dev_warn(dev, "chan %d step_avg truncating to %d\n",
130 chan, STEPCONFIG_AVG_16);
131 adc_dev->step_avg[i] = STEPCONFIG_AVG_16;
132 }
133
134 if (adc_dev->step_avg[i])
135 stepconfig =
136 STEPCONFIG_AVG(ffs(adc_dev->step_avg[i]) - 1) |
137 STEPCONFIG_FIFO1;
138 else
139 stepconfig = STEPCONFIG_FIFO1;
140
141 if (iio_buffer_enabled(indio_dev))
142 stepconfig |= STEPCONFIG_MODE_SWCNT;
143
144 tiadc_writel(adc_dev, REG_STEPCONFIG(steps),
145 stepconfig | STEPCONFIG_INP(chan) |
146 STEPCONFIG_INM_ADCREFM |
147 STEPCONFIG_RFP_VREFP |
148 STEPCONFIG_RFM_VREFN);
149
150 if (adc_dev->open_delay[i] > STEPDELAY_OPEN_MASK) {
151 dev_warn(dev, "chan %d open delay truncating to 0x3FFFF\n",
152 chan);
153 adc_dev->open_delay[i] = STEPDELAY_OPEN_MASK;
154 }
155
156 if (adc_dev->sample_delay[i] > 0xFF) {
157 dev_warn(dev, "chan %d sample delay truncating to 0xFF\n",
158 chan);
159 adc_dev->sample_delay[i] = 0xFF;
160 }
161
162 tiadc_writel(adc_dev, REG_STEPDELAY(steps),
163 STEPDELAY_OPEN(adc_dev->open_delay[i]) |
164 STEPDELAY_SAMPLE(adc_dev->sample_delay[i]));
165
166 adc_dev->channel_step[i] = steps;
167 steps++;
168 }
169 }
170
tiadc_irq_h(int irq,void * private)171 static irqreturn_t tiadc_irq_h(int irq, void *private)
172 {
173 struct iio_dev *indio_dev = private;
174 struct tiadc_device *adc_dev = iio_priv(indio_dev);
175 unsigned int status, config, adc_fsm;
176 unsigned short count = 0;
177
178 status = tiadc_readl(adc_dev, REG_IRQSTATUS);
179
180 /*
181 * ADC and touchscreen share the IRQ line.
182 * FIFO0 interrupts are used by TSC. Handle FIFO1 IRQs here only
183 */
184 if (status & IRQENB_FIFO1OVRRUN) {
185 /* FIFO Overrun. Clear flag. Disable/Enable ADC to recover */
186 config = tiadc_readl(adc_dev, REG_CTRL);
187 config &= ~(CNTRLREG_TSCSSENB);
188 tiadc_writel(adc_dev, REG_CTRL, config);
189 tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1OVRRUN
190 | IRQENB_FIFO1UNDRFLW | IRQENB_FIFO1THRES);
191
192 /* wait for idle state.
193 * ADC needs to finish the current conversion
194 * before disabling the module
195 */
196 do {
197 adc_fsm = tiadc_readl(adc_dev, REG_ADCFSM);
198 } while (adc_fsm != 0x10 && count++ < 100);
199
200 tiadc_writel(adc_dev, REG_CTRL, (config | CNTRLREG_TSCSSENB));
201 return IRQ_HANDLED;
202 } else if (status & IRQENB_FIFO1THRES) {
203 /* Disable irq and wake worker thread */
204 tiadc_writel(adc_dev, REG_IRQCLR, IRQENB_FIFO1THRES);
205 return IRQ_WAKE_THREAD;
206 }
207
208 return IRQ_NONE;
209 }
210
tiadc_worker_h(int irq,void * private)211 static irqreturn_t tiadc_worker_h(int irq, void *private)
212 {
213 struct iio_dev *indio_dev = private;
214 struct tiadc_device *adc_dev = iio_priv(indio_dev);
215 int i, k, fifo1count, read;
216 u16 *data = adc_dev->data;
217
218 fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
219 for (k = 0; k < fifo1count; k = k + i) {
220 for (i = 0; i < (indio_dev->scan_bytes)/2; i++) {
221 read = tiadc_readl(adc_dev, REG_FIFO1);
222 data[i] = read & FIFOREAD_DATA_MASK;
223 }
224 iio_push_to_buffers(indio_dev, (u8 *) data);
225 }
226
227 tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1THRES);
228 tiadc_writel(adc_dev, REG_IRQENABLE, IRQENB_FIFO1THRES);
229
230 return IRQ_HANDLED;
231 }
232
tiadc_dma_rx_complete(void * param)233 static void tiadc_dma_rx_complete(void *param)
234 {
235 struct iio_dev *indio_dev = param;
236 struct tiadc_device *adc_dev = iio_priv(indio_dev);
237 struct tiadc_dma *dma = &adc_dev->dma;
238 u8 *data;
239 int i;
240
241 data = dma->buf + dma->current_period * dma->period_size;
242 dma->current_period = 1 - dma->current_period; /* swap the buffer ID */
243
244 for (i = 0; i < dma->period_size; i += indio_dev->scan_bytes) {
245 iio_push_to_buffers(indio_dev, data);
246 data += indio_dev->scan_bytes;
247 }
248 }
249
tiadc_start_dma(struct iio_dev * indio_dev)250 static int tiadc_start_dma(struct iio_dev *indio_dev)
251 {
252 struct tiadc_device *adc_dev = iio_priv(indio_dev);
253 struct tiadc_dma *dma = &adc_dev->dma;
254 struct dma_async_tx_descriptor *desc;
255
256 dma->current_period = 0; /* We start to fill period 0 */
257 /*
258 * Make the fifo thresh as the multiple of total number of
259 * channels enabled, so make sure that cyclic DMA period
260 * length is also a multiple of total number of channels
261 * enabled. This ensures that no invalid data is reported
262 * to the stack via iio_push_to_buffers().
263 */
264 dma->fifo_thresh = rounddown(FIFO1_THRESHOLD + 1,
265 adc_dev->total_ch_enabled) - 1;
266 /* Make sure that period length is multiple of fifo thresh level */
267 dma->period_size = rounddown(DMA_BUFFER_SIZE / 2,
268 (dma->fifo_thresh + 1) * sizeof(u16));
269
270 dma->conf.src_maxburst = dma->fifo_thresh + 1;
271 dmaengine_slave_config(dma->chan, &dma->conf);
272
273 desc = dmaengine_prep_dma_cyclic(dma->chan, dma->addr,
274 dma->period_size * 2,
275 dma->period_size, DMA_DEV_TO_MEM,
276 DMA_PREP_INTERRUPT);
277 if (!desc)
278 return -EBUSY;
279
280 desc->callback = tiadc_dma_rx_complete;
281 desc->callback_param = indio_dev;
282
283 dma->cookie = dmaengine_submit(desc);
284
285 dma_async_issue_pending(dma->chan);
286
287 tiadc_writel(adc_dev, REG_FIFO1THR, dma->fifo_thresh);
288 tiadc_writel(adc_dev, REG_DMA1REQ, dma->fifo_thresh);
289 tiadc_writel(adc_dev, REG_DMAENABLE_SET, DMA_FIFO1);
290
291 return 0;
292 }
293
tiadc_buffer_preenable(struct iio_dev * indio_dev)294 static int tiadc_buffer_preenable(struct iio_dev *indio_dev)
295 {
296 struct tiadc_device *adc_dev = iio_priv(indio_dev);
297 int i, fifo1count;
298
299 tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES |
300 IRQENB_FIFO1OVRRUN |
301 IRQENB_FIFO1UNDRFLW));
302
303 /* Flush FIFO. Needed in corner cases in simultaneous tsc/adc use */
304 fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
305 for (i = 0; i < fifo1count; i++)
306 tiadc_readl(adc_dev, REG_FIFO1);
307
308 return 0;
309 }
310
tiadc_buffer_postenable(struct iio_dev * indio_dev)311 static int tiadc_buffer_postenable(struct iio_dev *indio_dev)
312 {
313 struct tiadc_device *adc_dev = iio_priv(indio_dev);
314 struct tiadc_dma *dma = &adc_dev->dma;
315 unsigned int irq_enable;
316 unsigned int enb = 0;
317 u8 bit;
318
319 tiadc_step_config(indio_dev);
320 for_each_set_bit(bit, indio_dev->active_scan_mask, adc_dev->channels) {
321 enb |= (get_adc_step_bit(adc_dev, bit) << 1);
322 adc_dev->total_ch_enabled++;
323 }
324 adc_dev->buffer_en_ch_steps = enb;
325
326 if (dma->chan)
327 tiadc_start_dma(indio_dev);
328
329 am335x_tsc_se_set_cache(adc_dev->mfd_tscadc, enb);
330
331 tiadc_writel(adc_dev, REG_IRQSTATUS, IRQENB_FIFO1THRES
332 | IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW);
333
334 irq_enable = IRQENB_FIFO1OVRRUN;
335 if (!dma->chan)
336 irq_enable |= IRQENB_FIFO1THRES;
337 tiadc_writel(adc_dev, REG_IRQENABLE, irq_enable);
338
339 return 0;
340 }
341
tiadc_buffer_predisable(struct iio_dev * indio_dev)342 static int tiadc_buffer_predisable(struct iio_dev *indio_dev)
343 {
344 struct tiadc_device *adc_dev = iio_priv(indio_dev);
345 struct tiadc_dma *dma = &adc_dev->dma;
346 int fifo1count, i;
347
348 tiadc_writel(adc_dev, REG_IRQCLR, (IRQENB_FIFO1THRES |
349 IRQENB_FIFO1OVRRUN | IRQENB_FIFO1UNDRFLW));
350 am335x_tsc_se_clr(adc_dev->mfd_tscadc, adc_dev->buffer_en_ch_steps);
351 adc_dev->buffer_en_ch_steps = 0;
352 adc_dev->total_ch_enabled = 0;
353 if (dma->chan) {
354 tiadc_writel(adc_dev, REG_DMAENABLE_CLEAR, 0x2);
355 dmaengine_terminate_async(dma->chan);
356 }
357
358 /* Flush FIFO of leftover data in the time it takes to disable adc */
359 fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
360 for (i = 0; i < fifo1count; i++)
361 tiadc_readl(adc_dev, REG_FIFO1);
362
363 return 0;
364 }
365
tiadc_buffer_postdisable(struct iio_dev * indio_dev)366 static int tiadc_buffer_postdisable(struct iio_dev *indio_dev)
367 {
368 tiadc_step_config(indio_dev);
369
370 return 0;
371 }
372
373 static const struct iio_buffer_setup_ops tiadc_buffer_setup_ops = {
374 .preenable = &tiadc_buffer_preenable,
375 .postenable = &tiadc_buffer_postenable,
376 .predisable = &tiadc_buffer_predisable,
377 .postdisable = &tiadc_buffer_postdisable,
378 };
379
tiadc_iio_buffered_hardware_setup(struct device * dev,struct iio_dev * indio_dev,irqreturn_t (* pollfunc_bh)(int irq,void * p),irqreturn_t (* pollfunc_th)(int irq,void * p),int irq,unsigned long flags,const struct iio_buffer_setup_ops * setup_ops)380 static int tiadc_iio_buffered_hardware_setup(struct device *dev,
381 struct iio_dev *indio_dev,
382 irqreturn_t (*pollfunc_bh)(int irq, void *p),
383 irqreturn_t (*pollfunc_th)(int irq, void *p),
384 int irq,
385 unsigned long flags,
386 const struct iio_buffer_setup_ops *setup_ops)
387 {
388 int ret;
389
390 ret = devm_iio_kfifo_buffer_setup(dev, indio_dev,
391 INDIO_BUFFER_SOFTWARE,
392 setup_ops);
393 if (ret)
394 return ret;
395
396 return devm_request_threaded_irq(dev, irq, pollfunc_th, pollfunc_bh,
397 flags, indio_dev->name, indio_dev);
398 }
399
400 static const char * const chan_name_ain[] = {
401 "AIN0",
402 "AIN1",
403 "AIN2",
404 "AIN3",
405 "AIN4",
406 "AIN5",
407 "AIN6",
408 "AIN7",
409 };
410
tiadc_channel_init(struct device * dev,struct iio_dev * indio_dev,int channels)411 static int tiadc_channel_init(struct device *dev, struct iio_dev *indio_dev,
412 int channels)
413 {
414 struct tiadc_device *adc_dev = iio_priv(indio_dev);
415 struct iio_chan_spec *chan_array;
416 struct iio_chan_spec *chan;
417 int i;
418
419 indio_dev->num_channels = channels;
420 chan_array = devm_kcalloc(dev, channels, sizeof(*chan_array),
421 GFP_KERNEL);
422 if (chan_array == NULL)
423 return -ENOMEM;
424
425 chan = chan_array;
426 for (i = 0; i < channels; i++, chan++) {
427
428 chan->type = IIO_VOLTAGE;
429 chan->indexed = 1;
430 chan->channel = adc_dev->channel_line[i];
431 chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
432 chan->datasheet_name = chan_name_ain[chan->channel];
433 chan->scan_index = i;
434 chan->scan_type.sign = 'u';
435 chan->scan_type.realbits = 12;
436 chan->scan_type.storagebits = 16;
437 }
438
439 indio_dev->channels = chan_array;
440
441 return 0;
442 }
443
tiadc_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)444 static int tiadc_read_raw(struct iio_dev *indio_dev,
445 struct iio_chan_spec const *chan,
446 int *val, int *val2, long mask)
447 {
448 struct tiadc_device *adc_dev = iio_priv(indio_dev);
449 int ret = IIO_VAL_INT;
450 int i, map_val;
451 unsigned int fifo1count, read, stepid;
452 bool found = false;
453 u32 step_en;
454 unsigned long timeout;
455
456 if (iio_buffer_enabled(indio_dev))
457 return -EBUSY;
458
459 step_en = get_adc_chan_step_mask(adc_dev, chan);
460 if (!step_en)
461 return -EINVAL;
462
463 mutex_lock(&adc_dev->fifo1_lock);
464 fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
465 while (fifo1count--)
466 tiadc_readl(adc_dev, REG_FIFO1);
467
468 am335x_tsc_se_set_once(adc_dev->mfd_tscadc, step_en);
469
470 timeout = jiffies + msecs_to_jiffies
471 (IDLE_TIMEOUT * adc_dev->channels);
472 /* Wait for Fifo threshold interrupt */
473 while (1) {
474 fifo1count = tiadc_readl(adc_dev, REG_FIFO1CNT);
475 if (fifo1count)
476 break;
477
478 if (time_after(jiffies, timeout)) {
479 am335x_tsc_se_adc_done(adc_dev->mfd_tscadc);
480 ret = -EAGAIN;
481 goto err_unlock;
482 }
483 }
484 map_val = adc_dev->channel_step[chan->scan_index];
485
486 /*
487 * We check the complete FIFO. We programmed just one entry but in case
488 * something went wrong we left empty handed (-EAGAIN previously) and
489 * then the value apeared somehow in the FIFO we would have two entries.
490 * Therefore we read every item and keep only the latest version of the
491 * requested channel.
492 */
493 for (i = 0; i < fifo1count; i++) {
494 read = tiadc_readl(adc_dev, REG_FIFO1);
495 stepid = read & FIFOREAD_CHNLID_MASK;
496 stepid = stepid >> 0x10;
497
498 if (stepid == map_val) {
499 read = read & FIFOREAD_DATA_MASK;
500 found = true;
501 *val = (u16) read;
502 }
503 }
504 am335x_tsc_se_adc_done(adc_dev->mfd_tscadc);
505
506 if (!found)
507 ret = -EBUSY;
508
509 err_unlock:
510 mutex_unlock(&adc_dev->fifo1_lock);
511 return ret;
512 }
513
514 static const struct iio_info tiadc_info = {
515 .read_raw = &tiadc_read_raw,
516 };
517
tiadc_request_dma(struct platform_device * pdev,struct tiadc_device * adc_dev)518 static int tiadc_request_dma(struct platform_device *pdev,
519 struct tiadc_device *adc_dev)
520 {
521 struct tiadc_dma *dma = &adc_dev->dma;
522 dma_cap_mask_t mask;
523
524 /* Default slave configuration parameters */
525 dma->conf.direction = DMA_DEV_TO_MEM;
526 dma->conf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
527 dma->conf.src_addr = adc_dev->mfd_tscadc->tscadc_phys_base + REG_FIFO1;
528
529 dma_cap_zero(mask);
530 dma_cap_set(DMA_CYCLIC, mask);
531
532 /* Get a channel for RX */
533 dma->chan = dma_request_chan(adc_dev->mfd_tscadc->dev, "fifo1");
534 if (IS_ERR(dma->chan)) {
535 int ret = PTR_ERR(dma->chan);
536
537 dma->chan = NULL;
538 return ret;
539 }
540
541 /* RX buffer */
542 dma->buf = dma_alloc_coherent(dma->chan->device->dev, DMA_BUFFER_SIZE,
543 &dma->addr, GFP_KERNEL);
544 if (!dma->buf)
545 goto err;
546
547 return 0;
548 err:
549 dma_release_channel(dma->chan);
550 return -ENOMEM;
551 }
552
tiadc_parse_dt(struct platform_device * pdev,struct tiadc_device * adc_dev)553 static int tiadc_parse_dt(struct platform_device *pdev,
554 struct tiadc_device *adc_dev)
555 {
556 struct device_node *node = pdev->dev.of_node;
557 struct property *prop;
558 const __be32 *cur;
559 int channels = 0;
560 u32 val;
561
562 of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) {
563 adc_dev->channel_line[channels] = val;
564
565 /* Set Default values for optional DT parameters */
566 adc_dev->open_delay[channels] = STEPCONFIG_OPENDLY;
567 adc_dev->sample_delay[channels] = STEPCONFIG_SAMPLEDLY;
568 adc_dev->step_avg[channels] = 16;
569
570 channels++;
571 }
572
573 of_property_read_u32_array(node, "ti,chan-step-avg",
574 adc_dev->step_avg, channels);
575 of_property_read_u32_array(node, "ti,chan-step-opendelay",
576 adc_dev->open_delay, channels);
577 of_property_read_u32_array(node, "ti,chan-step-sampledelay",
578 adc_dev->sample_delay, channels);
579
580 adc_dev->channels = channels;
581 return 0;
582 }
583
tiadc_probe(struct platform_device * pdev)584 static int tiadc_probe(struct platform_device *pdev)
585 {
586 struct iio_dev *indio_dev;
587 struct tiadc_device *adc_dev;
588 struct device_node *node = pdev->dev.of_node;
589 int err;
590
591 if (!node) {
592 dev_err(&pdev->dev, "Could not find valid DT data.\n");
593 return -EINVAL;
594 }
595
596 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc_dev));
597 if (indio_dev == NULL) {
598 dev_err(&pdev->dev, "failed to allocate iio device\n");
599 return -ENOMEM;
600 }
601 adc_dev = iio_priv(indio_dev);
602
603 adc_dev->mfd_tscadc = ti_tscadc_dev_get(pdev);
604 tiadc_parse_dt(pdev, adc_dev);
605
606 indio_dev->name = dev_name(&pdev->dev);
607 indio_dev->modes = INDIO_DIRECT_MODE;
608 indio_dev->info = &tiadc_info;
609
610 tiadc_step_config(indio_dev);
611 tiadc_writel(adc_dev, REG_FIFO1THR, FIFO1_THRESHOLD);
612 mutex_init(&adc_dev->fifo1_lock);
613
614 err = tiadc_channel_init(&pdev->dev, indio_dev, adc_dev->channels);
615 if (err < 0)
616 return err;
617
618 err = tiadc_iio_buffered_hardware_setup(&pdev->dev, indio_dev,
619 &tiadc_worker_h,
620 &tiadc_irq_h,
621 adc_dev->mfd_tscadc->irq,
622 IRQF_SHARED,
623 &tiadc_buffer_setup_ops);
624
625 if (err)
626 goto err_free_channels;
627
628 err = iio_device_register(indio_dev);
629 if (err)
630 goto err_buffer_unregister;
631
632 platform_set_drvdata(pdev, indio_dev);
633
634 err = tiadc_request_dma(pdev, adc_dev);
635 if (err && err != -ENODEV) {
636 dev_err_probe(&pdev->dev, err, "DMA request failed\n");
637 goto err_dma;
638 }
639
640 return 0;
641
642 err_dma:
643 iio_device_unregister(indio_dev);
644 err_buffer_unregister:
645 err_free_channels:
646 return err;
647 }
648
tiadc_remove(struct platform_device * pdev)649 static int tiadc_remove(struct platform_device *pdev)
650 {
651 struct iio_dev *indio_dev = platform_get_drvdata(pdev);
652 struct tiadc_device *adc_dev = iio_priv(indio_dev);
653 struct tiadc_dma *dma = &adc_dev->dma;
654 u32 step_en;
655
656 if (dma->chan) {
657 dma_free_coherent(dma->chan->device->dev, DMA_BUFFER_SIZE,
658 dma->buf, dma->addr);
659 dma_release_channel(dma->chan);
660 }
661 iio_device_unregister(indio_dev);
662
663 step_en = get_adc_step_mask(adc_dev);
664 am335x_tsc_se_clr(adc_dev->mfd_tscadc, step_en);
665
666 return 0;
667 }
668
tiadc_suspend(struct device * dev)669 static int __maybe_unused tiadc_suspend(struct device *dev)
670 {
671 struct iio_dev *indio_dev = dev_get_drvdata(dev);
672 struct tiadc_device *adc_dev = iio_priv(indio_dev);
673 unsigned int idle;
674
675 idle = tiadc_readl(adc_dev, REG_CTRL);
676 idle &= ~(CNTRLREG_TSCSSENB);
677 tiadc_writel(adc_dev, REG_CTRL, (idle |
678 CNTRLREG_POWERDOWN));
679
680 return 0;
681 }
682
tiadc_resume(struct device * dev)683 static int __maybe_unused tiadc_resume(struct device *dev)
684 {
685 struct iio_dev *indio_dev = dev_get_drvdata(dev);
686 struct tiadc_device *adc_dev = iio_priv(indio_dev);
687 unsigned int restore;
688
689 /* Make sure ADC is powered up */
690 restore = tiadc_readl(adc_dev, REG_CTRL);
691 restore &= ~(CNTRLREG_POWERDOWN);
692 tiadc_writel(adc_dev, REG_CTRL, restore);
693
694 tiadc_step_config(indio_dev);
695 am335x_tsc_se_set_cache(adc_dev->mfd_tscadc,
696 adc_dev->buffer_en_ch_steps);
697 return 0;
698 }
699
700 static SIMPLE_DEV_PM_OPS(tiadc_pm_ops, tiadc_suspend, tiadc_resume);
701
702 static const struct of_device_id ti_adc_dt_ids[] = {
703 { .compatible = "ti,am3359-adc", },
704 { }
705 };
706 MODULE_DEVICE_TABLE(of, ti_adc_dt_ids);
707
708 static struct platform_driver tiadc_driver = {
709 .driver = {
710 .name = "TI-am335x-adc",
711 .pm = &tiadc_pm_ops,
712 .of_match_table = ti_adc_dt_ids,
713 },
714 .probe = tiadc_probe,
715 .remove = tiadc_remove,
716 };
717 module_platform_driver(tiadc_driver);
718
719 MODULE_DESCRIPTION("TI ADC controller driver");
720 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>");
721 MODULE_LICENSE("GPL");
722