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