1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Aspeed AST2400/2500/2600 ADC
4 *
5 * Copyright (C) 2017 Google, Inc.
6 * Copyright (C) 2021 Aspeed Technology Inc.
7 *
8 * ADC clock formula:
9 * Ast2400/Ast2500:
10 * clock period = period of PCLK * 2 * (ADC0C[31:17] + 1) * (ADC0C[9:0] + 1)
11 * Ast2600:
12 * clock period = period of PCLK * 2 * (ADC0C[15:0] + 1)
13 */
14
15#include <linux/clk.h>
16#include <linux/clk-provider.h>
17#include <linux/err.h>
18#include <linux/errno.h>
19#include <linux/io.h>
20#include <linux/module.h>
21#include <linux/of_platform.h>
22#include <linux/platform_device.h>
23#include <linux/regulator/consumer.h>
24#include <linux/reset.h>
25#include <linux/spinlock.h>
26#include <linux/types.h>
27#include <linux/bitfield.h>
28#include <linux/regmap.h>
29#include <linux/mfd/syscon.h>
30
31#include <linux/iio/iio.h>
32#include <linux/iio/driver.h>
33#include <linux/iopoll.h>
34
35#define ASPEED_RESOLUTION_BITS 10
36#define ASPEED_CLOCKS_PER_SAMPLE 12
37
38#define ASPEED_REG_ENGINE_CONTROL 0x00
39#define ASPEED_REG_INTERRUPT_CONTROL 0x04
40#define ASPEED_REG_VGA_DETECT_CONTROL 0x08
41#define ASPEED_REG_CLOCK_CONTROL 0x0C
42#define ASPEED_REG_COMPENSATION_TRIM 0xC4
43/*
44 * The register offset between 0xC8~0xCC can be read and won't affect the
45 * hardware logic in each version of ADC.
46 */
47#define ASPEED_REG_MAX 0xD0
48
49#define ASPEED_ADC_ENGINE_ENABLE BIT(0)
50#define ASPEED_ADC_OP_MODE GENMASK(3, 1)
51#define ASPEED_ADC_OP_MODE_PWR_DOWN 0
52#define ASPEED_ADC_OP_MODE_STANDBY 1
53#define ASPEED_ADC_OP_MODE_NORMAL 7
54#define ASPEED_ADC_CTRL_COMPENSATION BIT(4)
55#define ASPEED_ADC_AUTO_COMPENSATION BIT(5)
56/*
57 * Bit 6 determines not only the reference voltage range but also the dividing
58 * circuit for battery sensing.
59 */
60#define ASPEED_ADC_REF_VOLTAGE GENMASK(7, 6)
61#define ASPEED_ADC_REF_VOLTAGE_2500mV 0
62#define ASPEED_ADC_REF_VOLTAGE_1200mV 1
63#define ASPEED_ADC_REF_VOLTAGE_EXT_HIGH 2
64#define ASPEED_ADC_REF_VOLTAGE_EXT_LOW 3
65#define ASPEED_ADC_BAT_SENSING_DIV BIT(6)
66#define ASPEED_ADC_BAT_SENSING_DIV_2_3 0
67#define ASPEED_ADC_BAT_SENSING_DIV_1_3 1
68#define ASPEED_ADC_CTRL_INIT_RDY BIT(8)
69#define ASPEED_ADC_CH7_MODE BIT(12)
70#define ASPEED_ADC_CH7_NORMAL 0
71#define ASPEED_ADC_CH7_BAT 1
72#define ASPEED_ADC_BAT_SENSING_ENABLE BIT(13)
73#define ASPEED_ADC_CTRL_CHANNEL GENMASK(31, 16)
74#define ASPEED_ADC_CTRL_CHANNEL_ENABLE(ch) FIELD_PREP(ASPEED_ADC_CTRL_CHANNEL, BIT(ch))
75
76#define ASPEED_ADC_INIT_POLLING_TIME 500
77#define ASPEED_ADC_INIT_TIMEOUT 500000
78/*
79 * When the sampling rate is too high, the ADC may not have enough charging
80 * time, resulting in a low voltage value. Thus, the default uses a slow
81 * sampling rate for most use cases.
82 */
83#define ASPEED_ADC_DEF_SAMPLING_RATE 65000
84
85struct aspeed_adc_trim_locate {
86 const unsigned int offset;
87 const unsigned int field;
88};
89
90struct aspeed_adc_model_data {
91 const char *model_name;
92 unsigned int min_sampling_rate; // Hz
93 unsigned int max_sampling_rate; // Hz
94 unsigned int vref_fixed_mv;
95 bool wait_init_sequence;
96 bool need_prescaler;
97 bool bat_sense_sup;
98 u8 scaler_bit_width;
99 unsigned int num_channels;
100 const struct aspeed_adc_trim_locate *trim_locate;
101};
102
103struct adc_gain {
104 u8 mult;
105 u8 div;
106};
107
108struct aspeed_adc_data {
109 struct device *dev;
110 const struct aspeed_adc_model_data *model_data;
111 struct regulator *regulator;
112 void __iomem *base;
113 spinlock_t clk_lock;
114 struct clk_hw *fixed_div_clk;
115 struct clk_hw *clk_prescaler;
116 struct clk_hw *clk_scaler;
117 struct reset_control *rst;
118 int vref_mv;
119 u32 sample_period_ns;
120 int cv;
121 bool battery_sensing;
122 struct adc_gain battery_mode_gain;
123};
124
125#define ASPEED_CHAN(_idx, _data_reg_addr) { \
126 .type = IIO_VOLTAGE, \
127 .indexed = 1, \
128 .channel = (_idx), \
129 .address = (_data_reg_addr), \
130 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
131 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
132 BIT(IIO_CHAN_INFO_SAMP_FREQ) | \
133 BIT(IIO_CHAN_INFO_OFFSET), \
134}
135
136static const struct iio_chan_spec aspeed_adc_iio_channels[] = {
137 ASPEED_CHAN(0, 0x10),
138 ASPEED_CHAN(1, 0x12),
139 ASPEED_CHAN(2, 0x14),
140 ASPEED_CHAN(3, 0x16),
141 ASPEED_CHAN(4, 0x18),
142 ASPEED_CHAN(5, 0x1A),
143 ASPEED_CHAN(6, 0x1C),
144 ASPEED_CHAN(7, 0x1E),
145 ASPEED_CHAN(8, 0x20),
146 ASPEED_CHAN(9, 0x22),
147 ASPEED_CHAN(10, 0x24),
148 ASPEED_CHAN(11, 0x26),
149 ASPEED_CHAN(12, 0x28),
150 ASPEED_CHAN(13, 0x2A),
151 ASPEED_CHAN(14, 0x2C),
152 ASPEED_CHAN(15, 0x2E),
153};
154
155#define ASPEED_BAT_CHAN(_idx, _data_reg_addr) { \
156 .type = IIO_VOLTAGE, \
157 .indexed = 1, \
158 .channel = (_idx), \
159 .address = (_data_reg_addr), \
160 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
161 BIT(IIO_CHAN_INFO_OFFSET), \
162 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
163 BIT(IIO_CHAN_INFO_SAMP_FREQ), \
164}
165static const struct iio_chan_spec aspeed_adc_iio_bat_channels[] = {
166 ASPEED_CHAN(0, 0x10),
167 ASPEED_CHAN(1, 0x12),
168 ASPEED_CHAN(2, 0x14),
169 ASPEED_CHAN(3, 0x16),
170 ASPEED_CHAN(4, 0x18),
171 ASPEED_CHAN(5, 0x1A),
172 ASPEED_CHAN(6, 0x1C),
173 ASPEED_BAT_CHAN(7, 0x1E),
174};
175
176static int aspeed_adc_set_trim_data(struct iio_dev *indio_dev)
177{
178 struct device_node *syscon;
179 struct regmap *scu;
180 u32 scu_otp, trimming_val;
181 struct aspeed_adc_data *data = iio_priv(indio_dev);
182
183 syscon = of_find_node_by_name(NULL, name: "syscon");
184 if (syscon == NULL) {
185 dev_warn(data->dev, "Couldn't find syscon node\n");
186 return -EOPNOTSUPP;
187 }
188 scu = syscon_node_to_regmap(np: syscon);
189 of_node_put(node: syscon);
190 if (IS_ERR(ptr: scu)) {
191 dev_warn(data->dev, "Failed to get syscon regmap\n");
192 return -EOPNOTSUPP;
193 }
194 if (data->model_data->trim_locate) {
195 if (regmap_read(map: scu, reg: data->model_data->trim_locate->offset,
196 val: &scu_otp)) {
197 dev_warn(data->dev,
198 "Failed to get adc trimming data\n");
199 trimming_val = 0x8;
200 } else {
201 trimming_val =
202 ((scu_otp) &
203 (data->model_data->trim_locate->field)) >>
204 __ffs(data->model_data->trim_locate->field);
205 if (!trimming_val)
206 trimming_val = 0x8;
207 }
208 dev_dbg(data->dev,
209 "trimming val = %d, offset = %08x, fields = %08x\n",
210 trimming_val, data->model_data->trim_locate->offset,
211 data->model_data->trim_locate->field);
212 writel(val: trimming_val, addr: data->base + ASPEED_REG_COMPENSATION_TRIM);
213 }
214 return 0;
215}
216
217static int aspeed_adc_compensation(struct iio_dev *indio_dev)
218{
219 struct aspeed_adc_data *data = iio_priv(indio_dev);
220 u32 index, adc_raw = 0;
221 u32 adc_engine_control_reg_val;
222
223 adc_engine_control_reg_val =
224 readl(addr: data->base + ASPEED_REG_ENGINE_CONTROL);
225 adc_engine_control_reg_val &= ~ASPEED_ADC_OP_MODE;
226 adc_engine_control_reg_val |=
227 (FIELD_PREP(ASPEED_ADC_OP_MODE, ASPEED_ADC_OP_MODE_NORMAL) |
228 ASPEED_ADC_ENGINE_ENABLE);
229 /*
230 * Enable compensating sensing:
231 * After that, the input voltage of ADC will force to half of the reference
232 * voltage. So the expected reading raw data will become half of the max
233 * value. We can get compensating value = 0x200 - ADC read raw value.
234 * It is recommended to average at least 10 samples to get a final CV.
235 */
236 writel(val: adc_engine_control_reg_val | ASPEED_ADC_CTRL_COMPENSATION |
237 ASPEED_ADC_CTRL_CHANNEL_ENABLE(0),
238 addr: data->base + ASPEED_REG_ENGINE_CONTROL);
239 /*
240 * After enable compensating sensing mode need to wait some time for ADC stable
241 * Experiment result is 1ms.
242 */
243 mdelay(1);
244
245 for (index = 0; index < 16; index++) {
246 /*
247 * Waiting for the sampling period ensures that the value acquired
248 * is fresh each time.
249 */
250 ndelay(data->sample_period_ns);
251 adc_raw += readw(addr: data->base + aspeed_adc_iio_channels[0].address);
252 }
253 adc_raw >>= 4;
254 data->cv = BIT(ASPEED_RESOLUTION_BITS - 1) - adc_raw;
255 writel(val: adc_engine_control_reg_val,
256 addr: data->base + ASPEED_REG_ENGINE_CONTROL);
257 dev_dbg(data->dev, "Compensating value = %d\n", data->cv);
258
259 return 0;
260}
261
262static int aspeed_adc_set_sampling_rate(struct iio_dev *indio_dev, u32 rate)
263{
264 struct aspeed_adc_data *data = iio_priv(indio_dev);
265
266 if (rate < data->model_data->min_sampling_rate ||
267 rate > data->model_data->max_sampling_rate)
268 return -EINVAL;
269 /* Each sampling needs 12 clocks to convert.*/
270 clk_set_rate(clk: data->clk_scaler->clk, rate: rate * ASPEED_CLOCKS_PER_SAMPLE);
271 rate = clk_get_rate(clk: data->clk_scaler->clk);
272 data->sample_period_ns = DIV_ROUND_UP_ULL(
273 (u64)NSEC_PER_SEC * ASPEED_CLOCKS_PER_SAMPLE, rate);
274 dev_dbg(data->dev, "Adc clock = %d sample period = %d ns", rate,
275 data->sample_period_ns);
276
277 return 0;
278}
279
280static int aspeed_adc_read_raw(struct iio_dev *indio_dev,
281 struct iio_chan_spec const *chan,
282 int *val, int *val2, long mask)
283{
284 struct aspeed_adc_data *data = iio_priv(indio_dev);
285 u32 adc_engine_control_reg_val;
286
287 switch (mask) {
288 case IIO_CHAN_INFO_RAW:
289 if (data->battery_sensing && chan->channel == 7) {
290 adc_engine_control_reg_val =
291 readl(addr: data->base + ASPEED_REG_ENGINE_CONTROL);
292 writel(val: adc_engine_control_reg_val |
293 FIELD_PREP(ASPEED_ADC_CH7_MODE,
294 ASPEED_ADC_CH7_BAT) |
295 ASPEED_ADC_BAT_SENSING_ENABLE,
296 addr: data->base + ASPEED_REG_ENGINE_CONTROL);
297 /*
298 * After enable battery sensing mode need to wait some time for adc stable
299 * Experiment result is 1ms.
300 */
301 mdelay(1);
302 *val = readw(addr: data->base + chan->address);
303 *val = (*val * data->battery_mode_gain.mult) /
304 data->battery_mode_gain.div;
305 /* Restore control register value */
306 writel(val: adc_engine_control_reg_val,
307 addr: data->base + ASPEED_REG_ENGINE_CONTROL);
308 } else
309 *val = readw(addr: data->base + chan->address);
310 return IIO_VAL_INT;
311
312 case IIO_CHAN_INFO_OFFSET:
313 if (data->battery_sensing && chan->channel == 7)
314 *val = (data->cv * data->battery_mode_gain.mult) /
315 data->battery_mode_gain.div;
316 else
317 *val = data->cv;
318 return IIO_VAL_INT;
319
320 case IIO_CHAN_INFO_SCALE:
321 *val = data->vref_mv;
322 *val2 = ASPEED_RESOLUTION_BITS;
323 return IIO_VAL_FRACTIONAL_LOG2;
324
325 case IIO_CHAN_INFO_SAMP_FREQ:
326 *val = clk_get_rate(clk: data->clk_scaler->clk) /
327 ASPEED_CLOCKS_PER_SAMPLE;
328 return IIO_VAL_INT;
329
330 default:
331 return -EINVAL;
332 }
333}
334
335static int aspeed_adc_write_raw(struct iio_dev *indio_dev,
336 struct iio_chan_spec const *chan,
337 int val, int val2, long mask)
338{
339 switch (mask) {
340 case IIO_CHAN_INFO_SAMP_FREQ:
341 return aspeed_adc_set_sampling_rate(indio_dev, rate: val);
342
343 case IIO_CHAN_INFO_SCALE:
344 case IIO_CHAN_INFO_RAW:
345 /*
346 * Technically, these could be written but the only reasons
347 * for doing so seem better handled in userspace. EPERM is
348 * returned to signal this is a policy choice rather than a
349 * hardware limitation.
350 */
351 return -EPERM;
352
353 default:
354 return -EINVAL;
355 }
356}
357
358static int aspeed_adc_reg_access(struct iio_dev *indio_dev,
359 unsigned int reg, unsigned int writeval,
360 unsigned int *readval)
361{
362 struct aspeed_adc_data *data = iio_priv(indio_dev);
363
364 if (!readval || reg % 4 || reg > ASPEED_REG_MAX)
365 return -EINVAL;
366
367 *readval = readl(addr: data->base + reg);
368
369 return 0;
370}
371
372static const struct iio_info aspeed_adc_iio_info = {
373 .read_raw = aspeed_adc_read_raw,
374 .write_raw = aspeed_adc_write_raw,
375 .debugfs_reg_access = aspeed_adc_reg_access,
376};
377
378static void aspeed_adc_unregister_fixed_divider(void *data)
379{
380 struct clk_hw *clk = data;
381
382 clk_hw_unregister_fixed_factor(hw: clk);
383}
384
385static void aspeed_adc_reset_assert(void *data)
386{
387 struct reset_control *rst = data;
388
389 reset_control_assert(rstc: rst);
390}
391
392static void aspeed_adc_clk_disable_unprepare(void *data)
393{
394 struct clk *clk = data;
395
396 clk_disable_unprepare(clk);
397}
398
399static void aspeed_adc_power_down(void *data)
400{
401 struct aspeed_adc_data *priv_data = data;
402
403 writel(FIELD_PREP(ASPEED_ADC_OP_MODE, ASPEED_ADC_OP_MODE_PWR_DOWN),
404 addr: priv_data->base + ASPEED_REG_ENGINE_CONTROL);
405}
406
407static void aspeed_adc_reg_disable(void *data)
408{
409 struct regulator *reg = data;
410
411 regulator_disable(regulator: reg);
412}
413
414static int aspeed_adc_vref_config(struct iio_dev *indio_dev)
415{
416 struct aspeed_adc_data *data = iio_priv(indio_dev);
417 int ret;
418 u32 adc_engine_control_reg_val;
419
420 if (data->model_data->vref_fixed_mv) {
421 data->vref_mv = data->model_data->vref_fixed_mv;
422 return 0;
423 }
424 adc_engine_control_reg_val =
425 readl(addr: data->base + ASPEED_REG_ENGINE_CONTROL);
426 data->regulator = devm_regulator_get_optional(dev: data->dev, id: "vref");
427 if (!IS_ERR(ptr: data->regulator)) {
428 ret = regulator_enable(regulator: data->regulator);
429 if (ret)
430 return ret;
431 ret = devm_add_action_or_reset(
432 data->dev, aspeed_adc_reg_disable, data->regulator);
433 if (ret)
434 return ret;
435 data->vref_mv = regulator_get_voltage(regulator: data->regulator);
436 /* Conversion from uV to mV */
437 data->vref_mv /= 1000;
438 if ((data->vref_mv >= 1550) && (data->vref_mv <= 2700))
439 writel(val: adc_engine_control_reg_val |
440 FIELD_PREP(
441 ASPEED_ADC_REF_VOLTAGE,
442 ASPEED_ADC_REF_VOLTAGE_EXT_HIGH),
443 addr: data->base + ASPEED_REG_ENGINE_CONTROL);
444 else if ((data->vref_mv >= 900) && (data->vref_mv <= 1650))
445 writel(val: adc_engine_control_reg_val |
446 FIELD_PREP(
447 ASPEED_ADC_REF_VOLTAGE,
448 ASPEED_ADC_REF_VOLTAGE_EXT_LOW),
449 addr: data->base + ASPEED_REG_ENGINE_CONTROL);
450 else {
451 dev_err(data->dev, "Regulator voltage %d not support",
452 data->vref_mv);
453 return -EOPNOTSUPP;
454 }
455 } else {
456 if (PTR_ERR(ptr: data->regulator) != -ENODEV)
457 return PTR_ERR(ptr: data->regulator);
458 data->vref_mv = 2500000;
459 of_property_read_u32(np: data->dev->of_node,
460 propname: "aspeed,int-vref-microvolt",
461 out_value: &data->vref_mv);
462 /* Conversion from uV to mV */
463 data->vref_mv /= 1000;
464 if (data->vref_mv == 2500)
465 writel(val: adc_engine_control_reg_val |
466 FIELD_PREP(ASPEED_ADC_REF_VOLTAGE,
467 ASPEED_ADC_REF_VOLTAGE_2500mV),
468 addr: data->base + ASPEED_REG_ENGINE_CONTROL);
469 else if (data->vref_mv == 1200)
470 writel(val: adc_engine_control_reg_val |
471 FIELD_PREP(ASPEED_ADC_REF_VOLTAGE,
472 ASPEED_ADC_REF_VOLTAGE_1200mV),
473 addr: data->base + ASPEED_REG_ENGINE_CONTROL);
474 else {
475 dev_err(data->dev, "Voltage %d not support", data->vref_mv);
476 return -EOPNOTSUPP;
477 }
478 }
479
480 return 0;
481}
482
483static int aspeed_adc_probe(struct platform_device *pdev)
484{
485 struct iio_dev *indio_dev;
486 struct aspeed_adc_data *data;
487 int ret;
488 u32 adc_engine_control_reg_val;
489 unsigned long scaler_flags = 0;
490 char clk_name[32], clk_parent_name[32];
491
492 indio_dev = devm_iio_device_alloc(parent: &pdev->dev, sizeof_priv: sizeof(*data));
493 if (!indio_dev)
494 return -ENOMEM;
495
496 data = iio_priv(indio_dev);
497 data->dev = &pdev->dev;
498 data->model_data = of_device_get_match_data(dev: &pdev->dev);
499 platform_set_drvdata(pdev, data: indio_dev);
500
501 data->base = devm_platform_ioremap_resource(pdev, index: 0);
502 if (IS_ERR(ptr: data->base))
503 return PTR_ERR(ptr: data->base);
504
505 /* Register ADC clock prescaler with source specified by device tree. */
506 spin_lock_init(&data->clk_lock);
507 snprintf(buf: clk_parent_name, ARRAY_SIZE(clk_parent_name), fmt: "%s",
508 of_clk_get_parent_name(np: pdev->dev.of_node, index: 0));
509 snprintf(buf: clk_name, ARRAY_SIZE(clk_name), fmt: "%s-fixed-div",
510 data->model_data->model_name);
511 data->fixed_div_clk = clk_hw_register_fixed_factor(
512 dev: &pdev->dev, name: clk_name, parent_name: clk_parent_name, flags: 0, mult: 1, div: 2);
513 if (IS_ERR(ptr: data->fixed_div_clk))
514 return PTR_ERR(ptr: data->fixed_div_clk);
515
516 ret = devm_add_action_or_reset(data->dev,
517 aspeed_adc_unregister_fixed_divider,
518 data->fixed_div_clk);
519 if (ret)
520 return ret;
521 snprintf(buf: clk_parent_name, ARRAY_SIZE(clk_parent_name), fmt: clk_name);
522
523 if (data->model_data->need_prescaler) {
524 snprintf(buf: clk_name, ARRAY_SIZE(clk_name), fmt: "%s-prescaler",
525 data->model_data->model_name);
526 data->clk_prescaler = devm_clk_hw_register_divider(
527 &pdev->dev, clk_name, clk_parent_name, 0,
528 data->base + ASPEED_REG_CLOCK_CONTROL, 17, 15, 0,
529 &data->clk_lock);
530 if (IS_ERR(ptr: data->clk_prescaler))
531 return PTR_ERR(ptr: data->clk_prescaler);
532 snprintf(buf: clk_parent_name, ARRAY_SIZE(clk_parent_name),
533 fmt: clk_name);
534 scaler_flags = CLK_SET_RATE_PARENT;
535 }
536 /*
537 * Register ADC clock scaler downstream from the prescaler. Allow rate
538 * setting to adjust the prescaler as well.
539 */
540 snprintf(buf: clk_name, ARRAY_SIZE(clk_name), fmt: "%s-scaler",
541 data->model_data->model_name);
542 data->clk_scaler = devm_clk_hw_register_divider(
543 &pdev->dev, clk_name, clk_parent_name, scaler_flags,
544 data->base + ASPEED_REG_CLOCK_CONTROL, 0,
545 data->model_data->scaler_bit_width,
546 data->model_data->need_prescaler ? CLK_DIVIDER_ONE_BASED : 0,
547 &data->clk_lock);
548 if (IS_ERR(ptr: data->clk_scaler))
549 return PTR_ERR(ptr: data->clk_scaler);
550
551 data->rst = devm_reset_control_get_shared(dev: &pdev->dev, NULL);
552 if (IS_ERR(ptr: data->rst)) {
553 dev_err(&pdev->dev,
554 "invalid or missing reset controller device tree entry");
555 return PTR_ERR(ptr: data->rst);
556 }
557 reset_control_deassert(rstc: data->rst);
558
559 ret = devm_add_action_or_reset(data->dev, aspeed_adc_reset_assert,
560 data->rst);
561 if (ret)
562 return ret;
563
564 ret = aspeed_adc_vref_config(indio_dev);
565 if (ret)
566 return ret;
567
568 ret = aspeed_adc_set_trim_data(indio_dev);
569 if (ret)
570 return ret;
571
572 if (of_find_property(np: data->dev->of_node, name: "aspeed,battery-sensing",
573 NULL)) {
574 if (data->model_data->bat_sense_sup) {
575 data->battery_sensing = 1;
576 if (readl(addr: data->base + ASPEED_REG_ENGINE_CONTROL) &
577 ASPEED_ADC_BAT_SENSING_DIV) {
578 data->battery_mode_gain.mult = 3;
579 data->battery_mode_gain.div = 1;
580 } else {
581 data->battery_mode_gain.mult = 3;
582 data->battery_mode_gain.div = 2;
583 }
584 } else
585 dev_warn(&pdev->dev,
586 "Failed to enable battery-sensing mode\n");
587 }
588
589 ret = clk_prepare_enable(clk: data->clk_scaler->clk);
590 if (ret)
591 return ret;
592 ret = devm_add_action_or_reset(data->dev,
593 aspeed_adc_clk_disable_unprepare,
594 data->clk_scaler->clk);
595 if (ret)
596 return ret;
597 ret = aspeed_adc_set_sampling_rate(indio_dev,
598 ASPEED_ADC_DEF_SAMPLING_RATE);
599 if (ret)
600 return ret;
601
602 adc_engine_control_reg_val =
603 readl(addr: data->base + ASPEED_REG_ENGINE_CONTROL);
604 adc_engine_control_reg_val |=
605 FIELD_PREP(ASPEED_ADC_OP_MODE, ASPEED_ADC_OP_MODE_NORMAL) |
606 ASPEED_ADC_ENGINE_ENABLE;
607 /* Enable engine in normal mode. */
608 writel(val: adc_engine_control_reg_val,
609 addr: data->base + ASPEED_REG_ENGINE_CONTROL);
610
611 ret = devm_add_action_or_reset(data->dev, aspeed_adc_power_down,
612 data);
613 if (ret)
614 return ret;
615
616 if (data->model_data->wait_init_sequence) {
617 /* Wait for initial sequence complete. */
618 ret = readl_poll_timeout(data->base + ASPEED_REG_ENGINE_CONTROL,
619 adc_engine_control_reg_val,
620 adc_engine_control_reg_val &
621 ASPEED_ADC_CTRL_INIT_RDY,
622 ASPEED_ADC_INIT_POLLING_TIME,
623 ASPEED_ADC_INIT_TIMEOUT);
624 if (ret)
625 return ret;
626 }
627
628 aspeed_adc_compensation(indio_dev);
629 /* Start all channels in normal mode. */
630 adc_engine_control_reg_val =
631 readl(addr: data->base + ASPEED_REG_ENGINE_CONTROL);
632 adc_engine_control_reg_val |= ASPEED_ADC_CTRL_CHANNEL;
633 writel(val: adc_engine_control_reg_val,
634 addr: data->base + ASPEED_REG_ENGINE_CONTROL);
635
636 indio_dev->name = data->model_data->model_name;
637 indio_dev->info = &aspeed_adc_iio_info;
638 indio_dev->modes = INDIO_DIRECT_MODE;
639 indio_dev->channels = data->battery_sensing ?
640 aspeed_adc_iio_bat_channels :
641 aspeed_adc_iio_channels;
642 indio_dev->num_channels = data->model_data->num_channels;
643
644 ret = devm_iio_device_register(data->dev, indio_dev);
645 return ret;
646}
647
648static const struct aspeed_adc_trim_locate ast2500_adc_trim = {
649 .offset = 0x154,
650 .field = GENMASK(31, 28),
651};
652
653static const struct aspeed_adc_trim_locate ast2600_adc0_trim = {
654 .offset = 0x5d0,
655 .field = GENMASK(3, 0),
656};
657
658static const struct aspeed_adc_trim_locate ast2600_adc1_trim = {
659 .offset = 0x5d0,
660 .field = GENMASK(7, 4),
661};
662
663static const struct aspeed_adc_model_data ast2400_model_data = {
664 .model_name = "ast2400-adc",
665 .vref_fixed_mv = 2500,
666 .min_sampling_rate = 10000,
667 .max_sampling_rate = 500000,
668 .need_prescaler = true,
669 .scaler_bit_width = 10,
670 .num_channels = 16,
671};
672
673static const struct aspeed_adc_model_data ast2500_model_data = {
674 .model_name = "ast2500-adc",
675 .vref_fixed_mv = 1800,
676 .min_sampling_rate = 1,
677 .max_sampling_rate = 1000000,
678 .wait_init_sequence = true,
679 .need_prescaler = true,
680 .scaler_bit_width = 10,
681 .num_channels = 16,
682 .trim_locate = &ast2500_adc_trim,
683};
684
685static const struct aspeed_adc_model_data ast2600_adc0_model_data = {
686 .model_name = "ast2600-adc0",
687 .min_sampling_rate = 10000,
688 .max_sampling_rate = 500000,
689 .wait_init_sequence = true,
690 .bat_sense_sup = true,
691 .scaler_bit_width = 16,
692 .num_channels = 8,
693 .trim_locate = &ast2600_adc0_trim,
694};
695
696static const struct aspeed_adc_model_data ast2600_adc1_model_data = {
697 .model_name = "ast2600-adc1",
698 .min_sampling_rate = 10000,
699 .max_sampling_rate = 500000,
700 .wait_init_sequence = true,
701 .bat_sense_sup = true,
702 .scaler_bit_width = 16,
703 .num_channels = 8,
704 .trim_locate = &ast2600_adc1_trim,
705};
706
707static const struct of_device_id aspeed_adc_matches[] = {
708 { .compatible = "aspeed,ast2400-adc", .data = &ast2400_model_data },
709 { .compatible = "aspeed,ast2500-adc", .data = &ast2500_model_data },
710 { .compatible = "aspeed,ast2600-adc0", .data = &ast2600_adc0_model_data },
711 { .compatible = "aspeed,ast2600-adc1", .data = &ast2600_adc1_model_data },
712 {},
713};
714MODULE_DEVICE_TABLE(of, aspeed_adc_matches);
715
716static struct platform_driver aspeed_adc_driver = {
717 .probe = aspeed_adc_probe,
718 .driver = {
719 .name = KBUILD_MODNAME,
720 .of_match_table = aspeed_adc_matches,
721 }
722};
723
724module_platform_driver(aspeed_adc_driver);
725
726MODULE_AUTHOR("Rick Altherr <raltherr@google.com>");
727MODULE_DESCRIPTION("Aspeed AST2400/2500/2600 ADC Driver");
728MODULE_LICENSE("GPL");
729

source code of linux/drivers/iio/adc/aspeed_adc.c