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v5.4
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Aspeed AST2400/2500 ADC
  4 *
  5 * Copyright (C) 2017 Google, Inc.
  6 */
  7
  8#include <linux/clk.h>
  9#include <linux/clk-provider.h>
 10#include <linux/err.h>
 11#include <linux/errno.h>
 12#include <linux/io.h>
 13#include <linux/module.h>
 14#include <linux/of_platform.h>
 15#include <linux/platform_device.h>
 16#include <linux/reset.h>
 17#include <linux/spinlock.h>
 18#include <linux/types.h>
 19
 20#include <linux/iio/iio.h>
 21#include <linux/iio/driver.h>
 22#include <linux/iopoll.h>
 23
 24#define ASPEED_RESOLUTION_BITS		10
 25#define ASPEED_CLOCKS_PER_SAMPLE	12
 26
 27#define ASPEED_REG_ENGINE_CONTROL	0x00
 28#define ASPEED_REG_INTERRUPT_CONTROL	0x04
 29#define ASPEED_REG_VGA_DETECT_CONTROL	0x08
 30#define ASPEED_REG_CLOCK_CONTROL	0x0C
 31#define ASPEED_REG_MAX			0xC0
 32
 33#define ASPEED_OPERATION_MODE_POWER_DOWN	(0x0 << 1)
 34#define ASPEED_OPERATION_MODE_STANDBY		(0x1 << 1)
 35#define ASPEED_OPERATION_MODE_NORMAL		(0x7 << 1)
 36
 37#define ASPEED_ENGINE_ENABLE		BIT(0)
 38
 39#define ASPEED_ADC_CTRL_INIT_RDY	BIT(8)
 40
 41#define ASPEED_ADC_INIT_POLLING_TIME	500
 42#define ASPEED_ADC_INIT_TIMEOUT		500000
 43
 44struct aspeed_adc_model_data {
 45	const char *model_name;
 46	unsigned int min_sampling_rate;	// Hz
 47	unsigned int max_sampling_rate;	// Hz
 48	unsigned int vref_voltage;	// mV
 49	bool wait_init_sequence;
 50};
 51
 52struct aspeed_adc_data {
 53	struct device		*dev;
 54	void __iomem		*base;
 55	spinlock_t		clk_lock;
 56	struct clk_hw		*clk_prescaler;
 57	struct clk_hw		*clk_scaler;
 58	struct reset_control	*rst;
 59};
 60
 61#define ASPEED_CHAN(_idx, _data_reg_addr) {			\
 62	.type = IIO_VOLTAGE,					\
 63	.indexed = 1,						\
 64	.channel = (_idx),					\
 65	.address = (_data_reg_addr),				\
 66	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
 67	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
 68				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
 69}
 70
 71static const struct iio_chan_spec aspeed_adc_iio_channels[] = {
 72	ASPEED_CHAN(0, 0x10),
 73	ASPEED_CHAN(1, 0x12),
 74	ASPEED_CHAN(2, 0x14),
 75	ASPEED_CHAN(3, 0x16),
 76	ASPEED_CHAN(4, 0x18),
 77	ASPEED_CHAN(5, 0x1A),
 78	ASPEED_CHAN(6, 0x1C),
 79	ASPEED_CHAN(7, 0x1E),
 80	ASPEED_CHAN(8, 0x20),
 81	ASPEED_CHAN(9, 0x22),
 82	ASPEED_CHAN(10, 0x24),
 83	ASPEED_CHAN(11, 0x26),
 84	ASPEED_CHAN(12, 0x28),
 85	ASPEED_CHAN(13, 0x2A),
 86	ASPEED_CHAN(14, 0x2C),
 87	ASPEED_CHAN(15, 0x2E),
 88};
 89
 90static int aspeed_adc_read_raw(struct iio_dev *indio_dev,
 91			       struct iio_chan_spec const *chan,
 92			       int *val, int *val2, long mask)
 93{
 94	struct aspeed_adc_data *data = iio_priv(indio_dev);
 95	const struct aspeed_adc_model_data *model_data =
 96			of_device_get_match_data(data->dev);
 97
 98	switch (mask) {
 99	case IIO_CHAN_INFO_RAW:
100		*val = readw(data->base + chan->address);
101		return IIO_VAL_INT;
102
103	case IIO_CHAN_INFO_SCALE:
104		*val = model_data->vref_voltage;
105		*val2 = ASPEED_RESOLUTION_BITS;
106		return IIO_VAL_FRACTIONAL_LOG2;
107
108	case IIO_CHAN_INFO_SAMP_FREQ:
109		*val = clk_get_rate(data->clk_scaler->clk) /
110				ASPEED_CLOCKS_PER_SAMPLE;
111		return IIO_VAL_INT;
112
113	default:
114		return -EINVAL;
115	}
116}
117
118static int aspeed_adc_write_raw(struct iio_dev *indio_dev,
119				struct iio_chan_spec const *chan,
120				int val, int val2, long mask)
121{
122	struct aspeed_adc_data *data = iio_priv(indio_dev);
123	const struct aspeed_adc_model_data *model_data =
124			of_device_get_match_data(data->dev);
125
126	switch (mask) {
127	case IIO_CHAN_INFO_SAMP_FREQ:
128		if (val < model_data->min_sampling_rate ||
129			val > model_data->max_sampling_rate)
130			return -EINVAL;
131
132		clk_set_rate(data->clk_scaler->clk,
133				val * ASPEED_CLOCKS_PER_SAMPLE);
134		return 0;
135
136	case IIO_CHAN_INFO_SCALE:
137	case IIO_CHAN_INFO_RAW:
138		/*
139		 * Technically, these could be written but the only reasons
140		 * for doing so seem better handled in userspace.  EPERM is
141		 * returned to signal this is a policy choice rather than a
142		 * hardware limitation.
143		 */
144		return -EPERM;
145
146	default:
147		return -EINVAL;
148	}
149}
150
151static int aspeed_adc_reg_access(struct iio_dev *indio_dev,
152				 unsigned int reg, unsigned int writeval,
153				 unsigned int *readval)
154{
155	struct aspeed_adc_data *data = iio_priv(indio_dev);
156
157	if (!readval || reg % 4 || reg > ASPEED_REG_MAX)
158		return -EINVAL;
159
160	*readval = readl(data->base + reg);
161
162	return 0;
163}
164
165static const struct iio_info aspeed_adc_iio_info = {
166	.read_raw = aspeed_adc_read_raw,
167	.write_raw = aspeed_adc_write_raw,
168	.debugfs_reg_access = aspeed_adc_reg_access,
169};
170
171static int aspeed_adc_probe(struct platform_device *pdev)
172{
173	struct iio_dev *indio_dev;
174	struct aspeed_adc_data *data;
175	const struct aspeed_adc_model_data *model_data;
176	struct resource *res;
177	const char *clk_parent_name;
178	int ret;
179	u32 adc_engine_control_reg_val;
180
181	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*data));
182	if (!indio_dev)
183		return -ENOMEM;
184
185	data = iio_priv(indio_dev);
186	data->dev = &pdev->dev;
187
188	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
189	data->base = devm_ioremap_resource(&pdev->dev, res);
190	if (IS_ERR(data->base))
191		return PTR_ERR(data->base);
192
193	/* Register ADC clock prescaler with source specified by device tree. */
194	spin_lock_init(&data->clk_lock);
195	clk_parent_name = of_clk_get_parent_name(pdev->dev.of_node, 0);
196
197	data->clk_prescaler = clk_hw_register_divider(
198				&pdev->dev, "prescaler", clk_parent_name, 0,
199				data->base + ASPEED_REG_CLOCK_CONTROL,
200				17, 15, 0, &data->clk_lock);
201	if (IS_ERR(data->clk_prescaler))
202		return PTR_ERR(data->clk_prescaler);
203
204	/*
205	 * Register ADC clock scaler downstream from the prescaler. Allow rate
206	 * setting to adjust the prescaler as well.
207	 */
208	data->clk_scaler = clk_hw_register_divider(
209				&pdev->dev, "scaler", "prescaler",
210				CLK_SET_RATE_PARENT,
211				data->base + ASPEED_REG_CLOCK_CONTROL,
212				0, 10, 0, &data->clk_lock);
213	if (IS_ERR(data->clk_scaler)) {
214		ret = PTR_ERR(data->clk_scaler);
215		goto scaler_error;
216	}
217
218	data->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
219	if (IS_ERR(data->rst)) {
220		dev_err(&pdev->dev,
221			"invalid or missing reset controller device tree entry");
222		ret = PTR_ERR(data->rst);
223		goto reset_error;
224	}
225	reset_control_deassert(data->rst);
226
227	model_data = of_device_get_match_data(&pdev->dev);
228
229	if (model_data->wait_init_sequence) {
230		/* Enable engine in normal mode. */
231		writel(ASPEED_OPERATION_MODE_NORMAL | ASPEED_ENGINE_ENABLE,
232		       data->base + ASPEED_REG_ENGINE_CONTROL);
233
234		/* Wait for initial sequence complete. */
235		ret = readl_poll_timeout(data->base + ASPEED_REG_ENGINE_CONTROL,
236					 adc_engine_control_reg_val,
237					 adc_engine_control_reg_val &
238					 ASPEED_ADC_CTRL_INIT_RDY,
239					 ASPEED_ADC_INIT_POLLING_TIME,
240					 ASPEED_ADC_INIT_TIMEOUT);
241		if (ret)
242			goto poll_timeout_error;
243	}
244
245	/* Start all channels in normal mode. */
246	ret = clk_prepare_enable(data->clk_scaler->clk);
247	if (ret)
248		goto clk_enable_error;
249
250	adc_engine_control_reg_val = GENMASK(31, 16) |
251		ASPEED_OPERATION_MODE_NORMAL | ASPEED_ENGINE_ENABLE;
252	writel(adc_engine_control_reg_val,
253		data->base + ASPEED_REG_ENGINE_CONTROL);
254
255	model_data = of_device_get_match_data(&pdev->dev);
256	indio_dev->name = model_data->model_name;
257	indio_dev->dev.parent = &pdev->dev;
258	indio_dev->info = &aspeed_adc_iio_info;
259	indio_dev->modes = INDIO_DIRECT_MODE;
260	indio_dev->channels = aspeed_adc_iio_channels;
261	indio_dev->num_channels = ARRAY_SIZE(aspeed_adc_iio_channels);
262
263	ret = iio_device_register(indio_dev);
264	if (ret)
265		goto iio_register_error;
266
267	return 0;
268
269iio_register_error:
270	writel(ASPEED_OPERATION_MODE_POWER_DOWN,
271		data->base + ASPEED_REG_ENGINE_CONTROL);
272	clk_disable_unprepare(data->clk_scaler->clk);
273clk_enable_error:
274poll_timeout_error:
275	reset_control_assert(data->rst);
276reset_error:
277	clk_hw_unregister_divider(data->clk_scaler);
278scaler_error:
279	clk_hw_unregister_divider(data->clk_prescaler);
280	return ret;
281}
282
283static int aspeed_adc_remove(struct platform_device *pdev)
284{
285	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
286	struct aspeed_adc_data *data = iio_priv(indio_dev);
287
288	iio_device_unregister(indio_dev);
289	writel(ASPEED_OPERATION_MODE_POWER_DOWN,
290		data->base + ASPEED_REG_ENGINE_CONTROL);
291	clk_disable_unprepare(data->clk_scaler->clk);
292	reset_control_assert(data->rst);
293	clk_hw_unregister_divider(data->clk_scaler);
294	clk_hw_unregister_divider(data->clk_prescaler);
295
296	return 0;
297}
298
299static const struct aspeed_adc_model_data ast2400_model_data = {
300	.model_name = "ast2400-adc",
301	.vref_voltage = 2500, // mV
302	.min_sampling_rate = 10000,
303	.max_sampling_rate = 500000,
304};
305
306static const struct aspeed_adc_model_data ast2500_model_data = {
307	.model_name = "ast2500-adc",
308	.vref_voltage = 1800, // mV
309	.min_sampling_rate = 1,
310	.max_sampling_rate = 1000000,
311	.wait_init_sequence = true,
312};
313
314static const struct of_device_id aspeed_adc_matches[] = {
315	{ .compatible = "aspeed,ast2400-adc", .data = &ast2400_model_data },
316	{ .compatible = "aspeed,ast2500-adc", .data = &ast2500_model_data },
317	{},
318};
319MODULE_DEVICE_TABLE(of, aspeed_adc_matches);
320
321static struct platform_driver aspeed_adc_driver = {
322	.probe = aspeed_adc_probe,
323	.remove = aspeed_adc_remove,
324	.driver = {
325		.name = KBUILD_MODNAME,
326		.of_match_table = aspeed_adc_matches,
327	}
328};
329
330module_platform_driver(aspeed_adc_driver);
331
332MODULE_AUTHOR("Rick Altherr <raltherr@google.com>");
333MODULE_DESCRIPTION("Aspeed AST2400/2500 ADC Driver");
334MODULE_LICENSE("GPL");
v5.9
  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Aspeed AST2400/2500 ADC
  4 *
  5 * Copyright (C) 2017 Google, Inc.
  6 */
  7
  8#include <linux/clk.h>
  9#include <linux/clk-provider.h>
 10#include <linux/err.h>
 11#include <linux/errno.h>
 12#include <linux/io.h>
 13#include <linux/module.h>
 14#include <linux/of_platform.h>
 15#include <linux/platform_device.h>
 16#include <linux/reset.h>
 17#include <linux/spinlock.h>
 18#include <linux/types.h>
 19
 20#include <linux/iio/iio.h>
 21#include <linux/iio/driver.h>
 22#include <linux/iopoll.h>
 23
 24#define ASPEED_RESOLUTION_BITS		10
 25#define ASPEED_CLOCKS_PER_SAMPLE	12
 26
 27#define ASPEED_REG_ENGINE_CONTROL	0x00
 28#define ASPEED_REG_INTERRUPT_CONTROL	0x04
 29#define ASPEED_REG_VGA_DETECT_CONTROL	0x08
 30#define ASPEED_REG_CLOCK_CONTROL	0x0C
 31#define ASPEED_REG_MAX			0xC0
 32
 33#define ASPEED_OPERATION_MODE_POWER_DOWN	(0x0 << 1)
 34#define ASPEED_OPERATION_MODE_STANDBY		(0x1 << 1)
 35#define ASPEED_OPERATION_MODE_NORMAL		(0x7 << 1)
 36
 37#define ASPEED_ENGINE_ENABLE		BIT(0)
 38
 39#define ASPEED_ADC_CTRL_INIT_RDY	BIT(8)
 40
 41#define ASPEED_ADC_INIT_POLLING_TIME	500
 42#define ASPEED_ADC_INIT_TIMEOUT		500000
 43
 44struct aspeed_adc_model_data {
 45	const char *model_name;
 46	unsigned int min_sampling_rate;	// Hz
 47	unsigned int max_sampling_rate;	// Hz
 48	unsigned int vref_voltage;	// mV
 49	bool wait_init_sequence;
 50};
 51
 52struct aspeed_adc_data {
 53	struct device		*dev;
 54	void __iomem		*base;
 55	spinlock_t		clk_lock;
 56	struct clk_hw		*clk_prescaler;
 57	struct clk_hw		*clk_scaler;
 58	struct reset_control	*rst;
 59};
 60
 61#define ASPEED_CHAN(_idx, _data_reg_addr) {			\
 62	.type = IIO_VOLTAGE,					\
 63	.indexed = 1,						\
 64	.channel = (_idx),					\
 65	.address = (_data_reg_addr),				\
 66	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
 67	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) |	\
 68				BIT(IIO_CHAN_INFO_SAMP_FREQ),	\
 69}
 70
 71static const struct iio_chan_spec aspeed_adc_iio_channels[] = {
 72	ASPEED_CHAN(0, 0x10),
 73	ASPEED_CHAN(1, 0x12),
 74	ASPEED_CHAN(2, 0x14),
 75	ASPEED_CHAN(3, 0x16),
 76	ASPEED_CHAN(4, 0x18),
 77	ASPEED_CHAN(5, 0x1A),
 78	ASPEED_CHAN(6, 0x1C),
 79	ASPEED_CHAN(7, 0x1E),
 80	ASPEED_CHAN(8, 0x20),
 81	ASPEED_CHAN(9, 0x22),
 82	ASPEED_CHAN(10, 0x24),
 83	ASPEED_CHAN(11, 0x26),
 84	ASPEED_CHAN(12, 0x28),
 85	ASPEED_CHAN(13, 0x2A),
 86	ASPEED_CHAN(14, 0x2C),
 87	ASPEED_CHAN(15, 0x2E),
 88};
 89
 90static int aspeed_adc_read_raw(struct iio_dev *indio_dev,
 91			       struct iio_chan_spec const *chan,
 92			       int *val, int *val2, long mask)
 93{
 94	struct aspeed_adc_data *data = iio_priv(indio_dev);
 95	const struct aspeed_adc_model_data *model_data =
 96			of_device_get_match_data(data->dev);
 97
 98	switch (mask) {
 99	case IIO_CHAN_INFO_RAW:
100		*val = readw(data->base + chan->address);
101		return IIO_VAL_INT;
102
103	case IIO_CHAN_INFO_SCALE:
104		*val = model_data->vref_voltage;
105		*val2 = ASPEED_RESOLUTION_BITS;
106		return IIO_VAL_FRACTIONAL_LOG2;
107
108	case IIO_CHAN_INFO_SAMP_FREQ:
109		*val = clk_get_rate(data->clk_scaler->clk) /
110				ASPEED_CLOCKS_PER_SAMPLE;
111		return IIO_VAL_INT;
112
113	default:
114		return -EINVAL;
115	}
116}
117
118static int aspeed_adc_write_raw(struct iio_dev *indio_dev,
119				struct iio_chan_spec const *chan,
120				int val, int val2, long mask)
121{
122	struct aspeed_adc_data *data = iio_priv(indio_dev);
123	const struct aspeed_adc_model_data *model_data =
124			of_device_get_match_data(data->dev);
125
126	switch (mask) {
127	case IIO_CHAN_INFO_SAMP_FREQ:
128		if (val < model_data->min_sampling_rate ||
129			val > model_data->max_sampling_rate)
130			return -EINVAL;
131
132		clk_set_rate(data->clk_scaler->clk,
133				val * ASPEED_CLOCKS_PER_SAMPLE);
134		return 0;
135
136	case IIO_CHAN_INFO_SCALE:
137	case IIO_CHAN_INFO_RAW:
138		/*
139		 * Technically, these could be written but the only reasons
140		 * for doing so seem better handled in userspace.  EPERM is
141		 * returned to signal this is a policy choice rather than a
142		 * hardware limitation.
143		 */
144		return -EPERM;
145
146	default:
147		return -EINVAL;
148	}
149}
150
151static int aspeed_adc_reg_access(struct iio_dev *indio_dev,
152				 unsigned int reg, unsigned int writeval,
153				 unsigned int *readval)
154{
155	struct aspeed_adc_data *data = iio_priv(indio_dev);
156
157	if (!readval || reg % 4 || reg > ASPEED_REG_MAX)
158		return -EINVAL;
159
160	*readval = readl(data->base + reg);
161
162	return 0;
163}
164
165static const struct iio_info aspeed_adc_iio_info = {
166	.read_raw = aspeed_adc_read_raw,
167	.write_raw = aspeed_adc_write_raw,
168	.debugfs_reg_access = aspeed_adc_reg_access,
169};
170
171static int aspeed_adc_probe(struct platform_device *pdev)
172{
173	struct iio_dev *indio_dev;
174	struct aspeed_adc_data *data;
175	const struct aspeed_adc_model_data *model_data;
 
176	const char *clk_parent_name;
177	int ret;
178	u32 adc_engine_control_reg_val;
179
180	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*data));
181	if (!indio_dev)
182		return -ENOMEM;
183
184	data = iio_priv(indio_dev);
185	data->dev = &pdev->dev;
186
187	data->base = devm_platform_ioremap_resource(pdev, 0);
 
188	if (IS_ERR(data->base))
189		return PTR_ERR(data->base);
190
191	/* Register ADC clock prescaler with source specified by device tree. */
192	spin_lock_init(&data->clk_lock);
193	clk_parent_name = of_clk_get_parent_name(pdev->dev.of_node, 0);
194
195	data->clk_prescaler = clk_hw_register_divider(
196				&pdev->dev, "prescaler", clk_parent_name, 0,
197				data->base + ASPEED_REG_CLOCK_CONTROL,
198				17, 15, 0, &data->clk_lock);
199	if (IS_ERR(data->clk_prescaler))
200		return PTR_ERR(data->clk_prescaler);
201
202	/*
203	 * Register ADC clock scaler downstream from the prescaler. Allow rate
204	 * setting to adjust the prescaler as well.
205	 */
206	data->clk_scaler = clk_hw_register_divider(
207				&pdev->dev, "scaler", "prescaler",
208				CLK_SET_RATE_PARENT,
209				data->base + ASPEED_REG_CLOCK_CONTROL,
210				0, 10, 0, &data->clk_lock);
211	if (IS_ERR(data->clk_scaler)) {
212		ret = PTR_ERR(data->clk_scaler);
213		goto scaler_error;
214	}
215
216	data->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
217	if (IS_ERR(data->rst)) {
218		dev_err(&pdev->dev,
219			"invalid or missing reset controller device tree entry");
220		ret = PTR_ERR(data->rst);
221		goto reset_error;
222	}
223	reset_control_deassert(data->rst);
224
225	model_data = of_device_get_match_data(&pdev->dev);
226
227	if (model_data->wait_init_sequence) {
228		/* Enable engine in normal mode. */
229		writel(ASPEED_OPERATION_MODE_NORMAL | ASPEED_ENGINE_ENABLE,
230		       data->base + ASPEED_REG_ENGINE_CONTROL);
231
232		/* Wait for initial sequence complete. */
233		ret = readl_poll_timeout(data->base + ASPEED_REG_ENGINE_CONTROL,
234					 adc_engine_control_reg_val,
235					 adc_engine_control_reg_val &
236					 ASPEED_ADC_CTRL_INIT_RDY,
237					 ASPEED_ADC_INIT_POLLING_TIME,
238					 ASPEED_ADC_INIT_TIMEOUT);
239		if (ret)
240			goto poll_timeout_error;
241	}
242
243	/* Start all channels in normal mode. */
244	ret = clk_prepare_enable(data->clk_scaler->clk);
245	if (ret)
246		goto clk_enable_error;
247
248	adc_engine_control_reg_val = GENMASK(31, 16) |
249		ASPEED_OPERATION_MODE_NORMAL | ASPEED_ENGINE_ENABLE;
250	writel(adc_engine_control_reg_val,
251		data->base + ASPEED_REG_ENGINE_CONTROL);
252
253	model_data = of_device_get_match_data(&pdev->dev);
254	indio_dev->name = model_data->model_name;
 
255	indio_dev->info = &aspeed_adc_iio_info;
256	indio_dev->modes = INDIO_DIRECT_MODE;
257	indio_dev->channels = aspeed_adc_iio_channels;
258	indio_dev->num_channels = ARRAY_SIZE(aspeed_adc_iio_channels);
259
260	ret = iio_device_register(indio_dev);
261	if (ret)
262		goto iio_register_error;
263
264	return 0;
265
266iio_register_error:
267	writel(ASPEED_OPERATION_MODE_POWER_DOWN,
268		data->base + ASPEED_REG_ENGINE_CONTROL);
269	clk_disable_unprepare(data->clk_scaler->clk);
270clk_enable_error:
271poll_timeout_error:
272	reset_control_assert(data->rst);
273reset_error:
274	clk_hw_unregister_divider(data->clk_scaler);
275scaler_error:
276	clk_hw_unregister_divider(data->clk_prescaler);
277	return ret;
278}
279
280static int aspeed_adc_remove(struct platform_device *pdev)
281{
282	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
283	struct aspeed_adc_data *data = iio_priv(indio_dev);
284
285	iio_device_unregister(indio_dev);
286	writel(ASPEED_OPERATION_MODE_POWER_DOWN,
287		data->base + ASPEED_REG_ENGINE_CONTROL);
288	clk_disable_unprepare(data->clk_scaler->clk);
289	reset_control_assert(data->rst);
290	clk_hw_unregister_divider(data->clk_scaler);
291	clk_hw_unregister_divider(data->clk_prescaler);
292
293	return 0;
294}
295
296static const struct aspeed_adc_model_data ast2400_model_data = {
297	.model_name = "ast2400-adc",
298	.vref_voltage = 2500, // mV
299	.min_sampling_rate = 10000,
300	.max_sampling_rate = 500000,
301};
302
303static const struct aspeed_adc_model_data ast2500_model_data = {
304	.model_name = "ast2500-adc",
305	.vref_voltage = 1800, // mV
306	.min_sampling_rate = 1,
307	.max_sampling_rate = 1000000,
308	.wait_init_sequence = true,
309};
310
311static const struct of_device_id aspeed_adc_matches[] = {
312	{ .compatible = "aspeed,ast2400-adc", .data = &ast2400_model_data },
313	{ .compatible = "aspeed,ast2500-adc", .data = &ast2500_model_data },
314	{},
315};
316MODULE_DEVICE_TABLE(of, aspeed_adc_matches);
317
318static struct platform_driver aspeed_adc_driver = {
319	.probe = aspeed_adc_probe,
320	.remove = aspeed_adc_remove,
321	.driver = {
322		.name = KBUILD_MODNAME,
323		.of_match_table = aspeed_adc_matches,
324	}
325};
326
327module_platform_driver(aspeed_adc_driver);
328
329MODULE_AUTHOR("Rick Altherr <raltherr@google.com>");
330MODULE_DESCRIPTION("Aspeed AST2400/2500 ADC Driver");
331MODULE_LICENSE("GPL");