1 // SPDX-License-Identifier: GPL-2.0-only
3 * Copyright 2016 Broadcom
6 #include <linux/module.h>
7 #include <linux/mod_devicetable.h>
10 #include <linux/mfd/syscon.h>
11 #include <linux/regmap.h>
12 #include <linux/delay.h>
13 #include <linux/interrupt.h>
14 #include <linux/platform_device.h>
16 #include <linux/iio/iio.h>
18 /* Below Register's are common to IPROC ADC and Touchscreen IP */
19 #define IPROC_REGCTL1 0x00
20 #define IPROC_REGCTL2 0x04
21 #define IPROC_INTERRUPT_THRES 0x08
22 #define IPROC_INTERRUPT_MASK 0x0c
23 #define IPROC_INTERRUPT_STATUS 0x10
24 #define IPROC_ANALOG_CONTROL 0x1c
25 #define IPROC_CONTROLLER_STATUS 0x14
26 #define IPROC_AUX_DATA 0x20
27 #define IPROC_SOFT_BYPASS_CONTROL 0x38
28 #define IPROC_SOFT_BYPASS_DATA 0x3C
30 /* IPROC ADC Channel register offsets */
31 #define IPROC_ADC_CHANNEL_REGCTL1 0x800
32 #define IPROC_ADC_CHANNEL_REGCTL2 0x804
33 #define IPROC_ADC_CHANNEL_STATUS 0x808
34 #define IPROC_ADC_CHANNEL_INTERRUPT_STATUS 0x80c
35 #define IPROC_ADC_CHANNEL_INTERRUPT_MASK 0x810
36 #define IPROC_ADC_CHANNEL_DATA 0x814
37 #define IPROC_ADC_CHANNEL_OFFSET 0x20
39 /* Bit definitions for IPROC_REGCTL2 */
40 #define IPROC_ADC_AUXIN_SCAN_ENA BIT(0)
41 #define IPROC_ADC_PWR_LDO BIT(5)
42 #define IPROC_ADC_PWR_ADC BIT(4)
43 #define IPROC_ADC_PWR_BG BIT(3)
44 #define IPROC_ADC_CONTROLLER_EN BIT(17)
46 /* Bit definitions for IPROC_INTERRUPT_MASK and IPROC_INTERRUPT_STATUS */
47 #define IPROC_ADC_AUXDATA_RDY_INTR BIT(3)
48 #define IPROC_ADC_INTR 9
49 #define IPROC_ADC_INTR_MASK (0xFF << IPROC_ADC_INTR)
51 /* Bit definitions for IPROC_ANALOG_CONTROL */
52 #define IPROC_ADC_CHANNEL_SEL 11
53 #define IPROC_ADC_CHANNEL_SEL_MASK (0x7 << IPROC_ADC_CHANNEL_SEL)
55 /* Bit definitions for IPROC_ADC_CHANNEL_REGCTL1 */
56 #define IPROC_ADC_CHANNEL_ROUNDS 0x2
57 #define IPROC_ADC_CHANNEL_ROUNDS_MASK (0x3F << IPROC_ADC_CHANNEL_ROUNDS)
58 #define IPROC_ADC_CHANNEL_MODE 0x1
59 #define IPROC_ADC_CHANNEL_MODE_MASK (0x1 << IPROC_ADC_CHANNEL_MODE)
60 #define IPROC_ADC_CHANNEL_MODE_TDM 0x1
61 #define IPROC_ADC_CHANNEL_MODE_SNAPSHOT 0x0
62 #define IPROC_ADC_CHANNEL_ENABLE 0x0
63 #define IPROC_ADC_CHANNEL_ENABLE_MASK 0x1
65 /* Bit definitions for IPROC_ADC_CHANNEL_REGCTL2 */
66 #define IPROC_ADC_CHANNEL_WATERMARK 0x0
67 #define IPROC_ADC_CHANNEL_WATERMARK_MASK \
68 (0x3F << IPROC_ADC_CHANNEL_WATERMARK)
70 #define IPROC_ADC_WATER_MARK_LEVEL 0x1
72 /* Bit definitions for IPROC_ADC_CHANNEL_STATUS */
73 #define IPROC_ADC_CHANNEL_DATA_LOST 0x0
74 #define IPROC_ADC_CHANNEL_DATA_LOST_MASK \
75 (0x0 << IPROC_ADC_CHANNEL_DATA_LOST)
76 #define IPROC_ADC_CHANNEL_VALID_ENTERIES 0x1
77 #define IPROC_ADC_CHANNEL_VALID_ENTERIES_MASK \
78 (0xFF << IPROC_ADC_CHANNEL_VALID_ENTERIES)
79 #define IPROC_ADC_CHANNEL_TOTAL_ENTERIES 0x9
80 #define IPROC_ADC_CHANNEL_TOTAL_ENTERIES_MASK \
81 (0xFF << IPROC_ADC_CHANNEL_TOTAL_ENTERIES)
83 /* Bit definitions for IPROC_ADC_CHANNEL_INTERRUPT_MASK */
84 #define IPROC_ADC_CHANNEL_WTRMRK_INTR 0x0
85 #define IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK \
86 (0x1 << IPROC_ADC_CHANNEL_WTRMRK_INTR)
87 #define IPROC_ADC_CHANNEL_FULL_INTR 0x1
88 #define IPROC_ADC_CHANNEL_FULL_INTR_MASK \
89 (0x1 << IPROC_ADC_IPROC_ADC_CHANNEL_FULL_INTR)
90 #define IPROC_ADC_CHANNEL_EMPTY_INTR 0x2
91 #define IPROC_ADC_CHANNEL_EMPTY_INTR_MASK \
92 (0x1 << IPROC_ADC_CHANNEL_EMPTY_INTR)
94 #define IPROC_ADC_WATER_MARK_INTR_ENABLE 0x1
96 /* Number of time to retry a set of the interrupt mask reg */
97 #define IPROC_ADC_INTMASK_RETRY_ATTEMPTS 10
99 #define IPROC_ADC_READ_TIMEOUT (HZ*2)
101 #define iproc_adc_dbg_reg(dev, priv, reg) \
104 regmap_read(priv->regmap, reg, &val); \
105 dev_dbg(dev, "%20s= 0x%08x\n", #reg, val); \
108 struct iproc_adc_priv
{
109 struct regmap
*regmap
;
115 struct completion completion
;
118 static void iproc_adc_reg_dump(struct iio_dev
*indio_dev
)
120 struct device
*dev
= &indio_dev
->dev
;
121 struct iproc_adc_priv
*adc_priv
= iio_priv(indio_dev
);
123 iproc_adc_dbg_reg(dev
, adc_priv
, IPROC_REGCTL1
);
124 iproc_adc_dbg_reg(dev
, adc_priv
, IPROC_REGCTL2
);
125 iproc_adc_dbg_reg(dev
, adc_priv
, IPROC_INTERRUPT_THRES
);
126 iproc_adc_dbg_reg(dev
, adc_priv
, IPROC_INTERRUPT_MASK
);
127 iproc_adc_dbg_reg(dev
, adc_priv
, IPROC_INTERRUPT_STATUS
);
128 iproc_adc_dbg_reg(dev
, adc_priv
, IPROC_CONTROLLER_STATUS
);
129 iproc_adc_dbg_reg(dev
, adc_priv
, IPROC_ANALOG_CONTROL
);
130 iproc_adc_dbg_reg(dev
, adc_priv
, IPROC_AUX_DATA
);
131 iproc_adc_dbg_reg(dev
, adc_priv
, IPROC_SOFT_BYPASS_CONTROL
);
132 iproc_adc_dbg_reg(dev
, adc_priv
, IPROC_SOFT_BYPASS_DATA
);
135 static irqreturn_t
iproc_adc_interrupt_thread(int irq
, void *data
)
137 u32 channel_intr_status
;
140 struct iio_dev
*indio_dev
= data
;
141 struct iproc_adc_priv
*adc_priv
= iio_priv(indio_dev
);
144 * This interrupt is shared with the touchscreen driver.
145 * Make sure this interrupt is intended for us.
146 * Handle only ADC channel specific interrupts.
148 regmap_read(adc_priv
->regmap
, IPROC_INTERRUPT_STATUS
, &intr_status
);
149 regmap_read(adc_priv
->regmap
, IPROC_INTERRUPT_MASK
, &intr_mask
);
150 intr_status
= intr_status
& intr_mask
;
151 channel_intr_status
= (intr_status
& IPROC_ADC_INTR_MASK
) >>
153 if (channel_intr_status
)
154 return IRQ_WAKE_THREAD
;
159 static irqreturn_t
iproc_adc_interrupt_handler(int irq
, void *data
)
161 irqreturn_t retval
= IRQ_NONE
;
162 struct iproc_adc_priv
*adc_priv
;
163 struct iio_dev
*indio_dev
= data
;
164 unsigned int valid_entries
;
170 adc_priv
= iio_priv(indio_dev
);
172 regmap_read(adc_priv
->regmap
, IPROC_INTERRUPT_STATUS
, &intr_status
);
173 dev_dbg(&indio_dev
->dev
, "iproc_adc_interrupt_handler(),INTRPT_STS:%x\n",
176 intr_channels
= (intr_status
& IPROC_ADC_INTR_MASK
) >> IPROC_ADC_INTR
;
178 regmap_read(adc_priv
->regmap
,
179 IPROC_ADC_CHANNEL_INTERRUPT_STATUS
+
180 IPROC_ADC_CHANNEL_OFFSET
* adc_priv
->chan_id
,
183 if (ch_intr_status
& IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK
) {
184 regmap_read(adc_priv
->regmap
,
185 IPROC_ADC_CHANNEL_STATUS
+
186 IPROC_ADC_CHANNEL_OFFSET
*
190 valid_entries
= ((channel_status
&
191 IPROC_ADC_CHANNEL_VALID_ENTERIES_MASK
) >>
192 IPROC_ADC_CHANNEL_VALID_ENTERIES
);
193 if (valid_entries
>= 1) {
194 regmap_read(adc_priv
->regmap
,
195 IPROC_ADC_CHANNEL_DATA
+
196 IPROC_ADC_CHANNEL_OFFSET
*
198 &adc_priv
->chan_val
);
199 complete(&adc_priv
->completion
);
201 dev_err(&indio_dev
->dev
,
202 "No data rcvd on channel %d\n",
205 regmap_write(adc_priv
->regmap
,
206 IPROC_ADC_CHANNEL_INTERRUPT_MASK
+
207 IPROC_ADC_CHANNEL_OFFSET
*
210 ~(IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK
)));
212 regmap_write(adc_priv
->regmap
,
213 IPROC_ADC_CHANNEL_INTERRUPT_STATUS
+
214 IPROC_ADC_CHANNEL_OFFSET
* adc_priv
->chan_id
,
216 regmap_write(adc_priv
->regmap
, IPROC_INTERRUPT_STATUS
,
218 retval
= IRQ_HANDLED
;
224 static int iproc_adc_do_read(struct iio_dev
*indio_dev
,
233 struct iproc_adc_priv
*adc_priv
= iio_priv(indio_dev
);
235 mutex_lock(&adc_priv
->mutex
);
238 * After a read is complete the ADC interrupts will be disabled so
239 * we can assume this section of code is safe from interrupts.
241 adc_priv
->chan_val
= -1;
242 adc_priv
->chan_id
= channel
;
244 reinit_completion(&adc_priv
->completion
);
245 /* Clear any pending interrupt */
246 regmap_update_bits(adc_priv
->regmap
, IPROC_INTERRUPT_STATUS
,
247 IPROC_ADC_INTR_MASK
| IPROC_ADC_AUXDATA_RDY_INTR
,
248 ((0x0 << channel
) << IPROC_ADC_INTR
) |
249 IPROC_ADC_AUXDATA_RDY_INTR
);
251 /* Configure channel for snapshot mode and enable */
252 val
= (BIT(IPROC_ADC_CHANNEL_ROUNDS
) |
253 (IPROC_ADC_CHANNEL_MODE_SNAPSHOT
<< IPROC_ADC_CHANNEL_MODE
) |
254 (0x1 << IPROC_ADC_CHANNEL_ENABLE
));
256 mask
= IPROC_ADC_CHANNEL_ROUNDS_MASK
| IPROC_ADC_CHANNEL_MODE_MASK
|
257 IPROC_ADC_CHANNEL_ENABLE_MASK
;
258 regmap_update_bits(adc_priv
->regmap
, (IPROC_ADC_CHANNEL_REGCTL1
+
259 IPROC_ADC_CHANNEL_OFFSET
* channel
),
262 /* Set the Watermark for a channel */
263 regmap_update_bits(adc_priv
->regmap
, (IPROC_ADC_CHANNEL_REGCTL2
+
264 IPROC_ADC_CHANNEL_OFFSET
* channel
),
265 IPROC_ADC_CHANNEL_WATERMARK_MASK
,
268 /* Enable water mark interrupt */
269 regmap_update_bits(adc_priv
->regmap
, (IPROC_ADC_CHANNEL_INTERRUPT_MASK
+
270 IPROC_ADC_CHANNEL_OFFSET
*
272 IPROC_ADC_CHANNEL_WTRMRK_INTR_MASK
,
273 IPROC_ADC_WATER_MARK_INTR_ENABLE
);
274 regmap_read(adc_priv
->regmap
, IPROC_INTERRUPT_MASK
, &val
);
276 /* Enable ADC interrupt for a channel */
277 val
|= (BIT(channel
) << IPROC_ADC_INTR
);
278 regmap_write(adc_priv
->regmap
, IPROC_INTERRUPT_MASK
, val
);
281 * There seems to be a very rare issue where writing to this register
282 * does not take effect. To work around the issue we will try multiple
283 * writes. In total we will spend about 10*10 = 100 us attempting this.
284 * Testing has shown that this may loop a few time, but we have never
285 * hit the full count.
287 regmap_read(adc_priv
->regmap
, IPROC_INTERRUPT_MASK
, &val_check
);
288 while (val_check
!= val
) {
291 if (failed_cnt
> IPROC_ADC_INTMASK_RETRY_ATTEMPTS
)
295 regmap_update_bits(adc_priv
->regmap
, IPROC_INTERRUPT_MASK
,
300 regmap_read(adc_priv
->regmap
, IPROC_INTERRUPT_MASK
, &val_check
);
304 dev_dbg(&indio_dev
->dev
,
305 "IntMask failed (%d times)", failed_cnt
);
306 if (failed_cnt
> IPROC_ADC_INTMASK_RETRY_ATTEMPTS
) {
307 dev_err(&indio_dev
->dev
,
308 "IntMask set failed. Read will likely fail.");
313 regmap_read(adc_priv
->regmap
, IPROC_INTERRUPT_MASK
, &val_check
);
315 if (wait_for_completion_timeout(&adc_priv
->completion
,
316 IPROC_ADC_READ_TIMEOUT
) > 0) {
318 /* Only the lower 16 bits are relevant */
319 *p_adc_data
= adc_priv
->chan_val
& 0xFFFF;
320 read_len
= sizeof(*p_adc_data
);
324 * We never got the interrupt, something went wrong.
325 * Perhaps the interrupt may still be coming, we do not want
326 * that now. Lets disable the ADC interrupt, and clear the
327 * status to put it back in to normal state.
329 read_len
= -ETIMEDOUT
;
332 mutex_unlock(&adc_priv
->mutex
);
337 regmap_update_bits(adc_priv
->regmap
, IPROC_INTERRUPT_MASK
,
339 ((0x0 << channel
) << IPROC_ADC_INTR
));
341 regmap_update_bits(adc_priv
->regmap
, IPROC_INTERRUPT_STATUS
,
343 ((0x0 << channel
) << IPROC_ADC_INTR
));
345 dev_err(&indio_dev
->dev
, "Timed out waiting for ADC data!\n");
346 iproc_adc_reg_dump(indio_dev
);
347 mutex_unlock(&adc_priv
->mutex
);
352 static int iproc_adc_enable(struct iio_dev
*indio_dev
)
356 struct iproc_adc_priv
*adc_priv
= iio_priv(indio_dev
);
359 /* Set i_amux = 3b'000, select channel 0 */
360 ret
= regmap_clear_bits(adc_priv
->regmap
, IPROC_ANALOG_CONTROL
,
361 IPROC_ADC_CHANNEL_SEL_MASK
);
363 dev_err(&indio_dev
->dev
,
364 "failed to write IPROC_ANALOG_CONTROL %d\n", ret
);
367 adc_priv
->chan_val
= -1;
370 * PWR up LDO, ADC, and Band Gap (0 to enable)
371 * Also enable ADC controller (set high)
373 ret
= regmap_read(adc_priv
->regmap
, IPROC_REGCTL2
, &val
);
375 dev_err(&indio_dev
->dev
,
376 "failed to read IPROC_REGCTL2 %d\n", ret
);
380 val
&= ~(IPROC_ADC_PWR_LDO
| IPROC_ADC_PWR_ADC
| IPROC_ADC_PWR_BG
);
382 ret
= regmap_write(adc_priv
->regmap
, IPROC_REGCTL2
, val
);
384 dev_err(&indio_dev
->dev
,
385 "failed to write IPROC_REGCTL2 %d\n", ret
);
389 ret
= regmap_read(adc_priv
->regmap
, IPROC_REGCTL2
, &val
);
391 dev_err(&indio_dev
->dev
,
392 "failed to read IPROC_REGCTL2 %d\n", ret
);
396 val
|= IPROC_ADC_CONTROLLER_EN
;
397 ret
= regmap_write(adc_priv
->regmap
, IPROC_REGCTL2
, val
);
399 dev_err(&indio_dev
->dev
,
400 "failed to write IPROC_REGCTL2 %d\n", ret
);
404 for (channel_id
= 0; channel_id
< indio_dev
->num_channels
;
406 ret
= regmap_write(adc_priv
->regmap
,
407 IPROC_ADC_CHANNEL_INTERRUPT_MASK
+
408 IPROC_ADC_CHANNEL_OFFSET
* channel_id
, 0);
410 dev_err(&indio_dev
->dev
,
411 "failed to write ADC_CHANNEL_INTERRUPT_MASK %d\n",
416 ret
= regmap_write(adc_priv
->regmap
,
417 IPROC_ADC_CHANNEL_INTERRUPT_STATUS
+
418 IPROC_ADC_CHANNEL_OFFSET
* channel_id
, 0);
420 dev_err(&indio_dev
->dev
,
421 "failed to write ADC_CHANNEL_INTERRUPT_STATUS %d\n",
430 static void iproc_adc_disable(struct iio_dev
*indio_dev
)
434 struct iproc_adc_priv
*adc_priv
= iio_priv(indio_dev
);
436 ret
= regmap_read(adc_priv
->regmap
, IPROC_REGCTL2
, &val
);
438 dev_err(&indio_dev
->dev
,
439 "failed to read IPROC_REGCTL2 %d\n", ret
);
443 val
&= ~IPROC_ADC_CONTROLLER_EN
;
444 ret
= regmap_write(adc_priv
->regmap
, IPROC_REGCTL2
, val
);
446 dev_err(&indio_dev
->dev
,
447 "failed to write IPROC_REGCTL2 %d\n", ret
);
452 static int iproc_adc_read_raw(struct iio_dev
*indio_dev
,
453 struct iio_chan_spec
const *chan
,
462 case IIO_CHAN_INFO_RAW
:
463 err
= iproc_adc_do_read(indio_dev
, chan
->channel
, &adc_data
);
468 case IIO_CHAN_INFO_SCALE
:
469 switch (chan
->type
) {
473 return IIO_VAL_FRACTIONAL_LOG2
;
482 static const struct iio_info iproc_adc_iio_info
= {
483 .read_raw
= &iproc_adc_read_raw
,
486 #define IPROC_ADC_CHANNEL(_index, _id) { \
487 .type = IIO_VOLTAGE, \
490 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
491 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
492 .datasheet_name = _id, \
495 static const struct iio_chan_spec iproc_adc_iio_channels
[] = {
496 IPROC_ADC_CHANNEL(0, "adc0"),
497 IPROC_ADC_CHANNEL(1, "adc1"),
498 IPROC_ADC_CHANNEL(2, "adc2"),
499 IPROC_ADC_CHANNEL(3, "adc3"),
500 IPROC_ADC_CHANNEL(4, "adc4"),
501 IPROC_ADC_CHANNEL(5, "adc5"),
502 IPROC_ADC_CHANNEL(6, "adc6"),
503 IPROC_ADC_CHANNEL(7, "adc7"),
506 static int iproc_adc_probe(struct platform_device
*pdev
)
508 struct iproc_adc_priv
*adc_priv
;
509 struct iio_dev
*indio_dev
= NULL
;
512 indio_dev
= devm_iio_device_alloc(&pdev
->dev
,
515 dev_err(&pdev
->dev
, "failed to allocate iio device\n");
519 adc_priv
= iio_priv(indio_dev
);
520 platform_set_drvdata(pdev
, indio_dev
);
522 mutex_init(&adc_priv
->mutex
);
524 init_completion(&adc_priv
->completion
);
526 adc_priv
->regmap
= syscon_regmap_lookup_by_phandle(pdev
->dev
.of_node
,
528 if (IS_ERR(adc_priv
->regmap
)) {
529 dev_err(&pdev
->dev
, "failed to get handle for tsc syscon\n");
530 ret
= PTR_ERR(adc_priv
->regmap
);
534 adc_priv
->adc_clk
= devm_clk_get(&pdev
->dev
, "tsc_clk");
535 if (IS_ERR(adc_priv
->adc_clk
)) {
537 "failed getting clock tsc_clk\n");
538 ret
= PTR_ERR(adc_priv
->adc_clk
);
542 adc_priv
->irqno
= platform_get_irq(pdev
, 0);
543 if (adc_priv
->irqno
< 0)
544 return adc_priv
->irqno
;
546 ret
= regmap_clear_bits(adc_priv
->regmap
, IPROC_REGCTL2
,
547 IPROC_ADC_AUXIN_SCAN_ENA
);
549 dev_err(&pdev
->dev
, "failed to write IPROC_REGCTL2 %d\n", ret
);
553 ret
= devm_request_threaded_irq(&pdev
->dev
, adc_priv
->irqno
,
554 iproc_adc_interrupt_handler
,
555 iproc_adc_interrupt_thread
,
556 IRQF_SHARED
, "iproc-adc", indio_dev
);
558 dev_err(&pdev
->dev
, "request_irq error %d\n", ret
);
562 ret
= clk_prepare_enable(adc_priv
->adc_clk
);
565 "clk_prepare_enable failed %d\n", ret
);
569 ret
= iproc_adc_enable(indio_dev
);
571 dev_err(&pdev
->dev
, "failed to enable adc %d\n", ret
);
575 indio_dev
->name
= "iproc-static-adc";
576 indio_dev
->info
= &iproc_adc_iio_info
;
577 indio_dev
->modes
= INDIO_DIRECT_MODE
;
578 indio_dev
->channels
= iproc_adc_iio_channels
;
579 indio_dev
->num_channels
= ARRAY_SIZE(iproc_adc_iio_channels
);
581 ret
= iio_device_register(indio_dev
);
583 dev_err(&pdev
->dev
, "iio_device_register failed:err %d\n", ret
);
590 iproc_adc_disable(indio_dev
);
592 clk_disable_unprepare(adc_priv
->adc_clk
);
597 static void iproc_adc_remove(struct platform_device
*pdev
)
599 struct iio_dev
*indio_dev
= platform_get_drvdata(pdev
);
600 struct iproc_adc_priv
*adc_priv
= iio_priv(indio_dev
);
602 iio_device_unregister(indio_dev
);
603 iproc_adc_disable(indio_dev
);
604 clk_disable_unprepare(adc_priv
->adc_clk
);
607 static const struct of_device_id iproc_adc_of_match
[] = {
608 {.compatible
= "brcm,iproc-static-adc", },
611 MODULE_DEVICE_TABLE(of
, iproc_adc_of_match
);
613 static struct platform_driver iproc_adc_driver
= {
614 .probe
= iproc_adc_probe
,
615 .remove_new
= iproc_adc_remove
,
617 .name
= "iproc-static-adc",
618 .of_match_table
= iproc_adc_of_match
,
621 module_platform_driver(iproc_adc_driver
);
623 MODULE_DESCRIPTION("Broadcom iProc ADC controller driver");
624 MODULE_AUTHOR("Raveendra Padasalagi <raveendra.padasalagi@broadcom.com>");
625 MODULE_LICENSE("GPL v2");