[mirror_ubuntu-jammy-kernel.git] / drivers / iio / adc / ti-adc12138.c

/*
 * ADC12130/ADC12132/ADC12138 12-bit plus sign ADC driver
 *
 * Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com>
 *
 * This file is subject to the terms and conditions of version 2 of
 * the GNU General Public License.  See the file COPYING in the main
 * directory of this archive for more details.
 *
 * Datasheet: http://www.ti.com/lit/ds/symlink/adc12138.pdf
 */

#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/completion.h>
#include <linux/clk.h>
#include <linux/spi/spi.h>
#include <linux/iio/iio.h>
#include <linux/iio/buffer.h>
#include <linux/iio/trigger.h>
#include <linux/iio/triggered_buffer.h>
#include <linux/iio/trigger_consumer.h>
#include <linux/regulator/consumer.h>

#define ADC12138_MODE_AUTO_CAL			0x08
#define ADC12138_MODE_READ_STATUS		0x0c
#define ADC12138_MODE_ACQUISITION_TIME_6	0x0e
#define ADC12138_MODE_ACQUISITION_TIME_10	0x4e
#define ADC12138_MODE_ACQUISITION_TIME_18	0x8e
#define ADC12138_MODE_ACQUISITION_TIME_34	0xce

#define ADC12138_STATUS_CAL			BIT(6)

enum {
	adc12130,
	adc12132,
	adc12138,
};

struct adc12138 {
	struct spi_device *spi;
	unsigned int id;
	/* conversion clock */
	struct clk *cclk;
	/* positive analog voltage reference */
	struct regulator *vref_p;
	/* negative analog voltage reference */
	struct regulator *vref_n;
	struct mutex lock;
	struct completion complete;
	/* The number of cclk periods for the S/H's acquisition time */
	unsigned int acquisition_time;

	u8 tx_buf[2] ____cacheline_aligned;
	u8 rx_buf[2];
};

#define ADC12138_VOLTAGE_CHANNEL(chan)					\
	{								\
		.type = IIO_VOLTAGE,					\
		.indexed = 1,						\
		.channel = chan,					\
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE)	\
					| BIT(IIO_CHAN_INFO_OFFSET),	\
		.scan_index = chan,					\
		.scan_type = {						\
			.sign = 's',					\
			.realbits = 13,					\
			.storagebits = 16,				\
			.shift = 3,					\
			.endianness = IIO_BE,				\
		},							\
	}

#define ADC12138_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si)			\
	{								\
		.type = IIO_VOLTAGE,					\
		.indexed = 1,						\
		.channel = (chan1),					\
		.channel2 = (chan2),					\
		.differential = 1,					\
		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE)	\
					| BIT(IIO_CHAN_INFO_OFFSET),	\
		.scan_index = si,					\
		.scan_type = {						\
			.sign = 's',					\
			.realbits = 13,					\
			.storagebits = 16,				\
			.shift = 3,					\
			.endianness = IIO_BE,				\
		},							\
	}

static const struct iio_chan_spec adc12132_channels[] = {
	ADC12138_VOLTAGE_CHANNEL(0),
	ADC12138_VOLTAGE_CHANNEL(1),
	ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 2),
	ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 3),
	IIO_CHAN_SOFT_TIMESTAMP(4),
};

static const struct iio_chan_spec adc12138_channels[] = {
	ADC12138_VOLTAGE_CHANNEL(0),
	ADC12138_VOLTAGE_CHANNEL(1),
	ADC12138_VOLTAGE_CHANNEL(2),
	ADC12138_VOLTAGE_CHANNEL(3),
	ADC12138_VOLTAGE_CHANNEL(4),
	ADC12138_VOLTAGE_CHANNEL(5),
	ADC12138_VOLTAGE_CHANNEL(6),
	ADC12138_VOLTAGE_CHANNEL(7),
	ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 8),
	ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 9),
	ADC12138_VOLTAGE_CHANNEL_DIFF(2, 3, 10),
	ADC12138_VOLTAGE_CHANNEL_DIFF(3, 2, 11),
	ADC12138_VOLTAGE_CHANNEL_DIFF(4, 5, 12),
	ADC12138_VOLTAGE_CHANNEL_DIFF(5, 4, 13),
	ADC12138_VOLTAGE_CHANNEL_DIFF(6, 7, 14),
	ADC12138_VOLTAGE_CHANNEL_DIFF(7, 6, 15),
	IIO_CHAN_SOFT_TIMESTAMP(16),
};

static int adc12138_mode_programming(struct adc12138 *adc, u8 mode,
				     void *rx_buf, int len)
{
	struct spi_transfer xfer = {
		.tx_buf = adc->tx_buf,
		.rx_buf = adc->rx_buf,
		.len = len,
	};
	int ret;

	/* Skip unused bits for ADC12130 and ADC12132 */
	if (adc->id != adc12138)
		mode = (mode & 0xc0) | ((mode & 0x0f) << 2);

	adc->tx_buf[0] = mode;

	ret = spi_sync_transfer(adc->spi, &xfer, 1);
	if (ret)
		return ret;

	memcpy(rx_buf, adc->rx_buf, len);

	return 0;
}

static int adc12138_read_status(struct adc12138 *adc)
{
	u8 rx_buf[2];
	int ret;

	ret = adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
					rx_buf, 2);
	if (ret)
		return ret;

	return (rx_buf[0] << 1) | (rx_buf[1] >> 7);
}

static int __adc12138_start_conv(struct adc12138 *adc,
				 struct iio_chan_spec const *channel,
				 void *data, int len)

{
	static const u8 ch_to_mux[] = { 0, 4, 1, 5, 2, 6, 3, 7 };
	u8 mode = (ch_to_mux[channel->channel] << 4) |
		  (channel->differential ? 0 : 0x80);

	return adc12138_mode_programming(adc, mode, data, len);
}

static int adc12138_start_conv(struct adc12138 *adc,
			       struct iio_chan_spec const *channel)
{
	u8 trash;

	return __adc12138_start_conv(adc, channel, &trash, 1);
}

static int adc12138_start_and_read_conv(struct adc12138 *adc,
					struct iio_chan_spec const *channel,
					__be16 *data)
{
	return __adc12138_start_conv(adc, channel, data, 2);
}

static int adc12138_read_conv_data(struct adc12138 *adc, __be16 *value)
{
	/* Issue a read status instruction and read previous conversion data */
	return adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
					 value, sizeof(*value));
}

static int adc12138_wait_eoc(struct adc12138 *adc, unsigned long timeout)
{
	if (!wait_for_completion_timeout(&adc->complete, timeout))
		return -ETIMEDOUT;

	return 0;
}

static int adc12138_adc_conversion(struct adc12138 *adc,
				   struct iio_chan_spec const *channel,
				   __be16 *value)
{
	int ret;

	reinit_completion(&adc->complete);

	ret = adc12138_start_conv(adc, channel);
	if (ret)
		return ret;

	ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
	if (ret)
		return ret;

	return adc12138_read_conv_data(adc, value);
}

static int adc12138_read_raw(struct iio_dev *iio,
			     struct iio_chan_spec const *channel, int *value,
			     int *shift, long mask)
{
	struct adc12138 *adc = iio_priv(iio);
	int ret;
	__be16 data;

	switch (mask) {
	case IIO_CHAN_INFO_RAW:
		mutex_lock(&adc->lock);
		ret = adc12138_adc_conversion(adc, channel, &data);
		mutex_unlock(&adc->lock);
		if (ret)
			return ret;

		*value = sign_extend32(be16_to_cpu(data) >> 3, 12);

		return IIO_VAL_INT;
	case IIO_CHAN_INFO_SCALE:
		ret = regulator_get_voltage(adc->vref_p);
		if (ret < 0)
			return ret;
		*value = ret;

		if (!IS_ERR(adc->vref_n)) {
			ret = regulator_get_voltage(adc->vref_n);
			if (ret < 0)
				return ret;
			*value -= ret;
		}

		/* convert regulator output voltage to mV */
		*value /= 1000;
		*shift = channel->scan_type.realbits - 1;

		return IIO_VAL_FRACTIONAL_LOG2;
	case IIO_CHAN_INFO_OFFSET:
		if (!IS_ERR(adc->vref_n)) {
			*value = regulator_get_voltage(adc->vref_n);
			if (*value < 0)
				return *value;
		} else {
			*value = 0;
		}

		/* convert regulator output voltage to mV */
		*value /= 1000;

		return IIO_VAL_INT;
	}

	return -EINVAL;
}

static const struct iio_info adc12138_info = {
	.read_raw = adc12138_read_raw,
};

static int adc12138_init(struct adc12138 *adc)
{
	int ret;
	int status;
	u8 mode;
	u8 trash;

	reinit_completion(&adc->complete);

	ret = adc12138_mode_programming(adc, ADC12138_MODE_AUTO_CAL, &trash, 1);
	if (ret)
		return ret;

	/* data output at this time has no significance */
	status = adc12138_read_status(adc);
	if (status < 0)
		return status;

	adc12138_wait_eoc(adc, msecs_to_jiffies(100));

	status = adc12138_read_status(adc);
	if (status & ADC12138_STATUS_CAL) {
		dev_warn(&adc->spi->dev,
			"Auto Cal sequence is still in progress: %#x\n",
			status);
		return -EIO;
	}

	switch (adc->acquisition_time) {
	case 6:
		mode = ADC12138_MODE_ACQUISITION_TIME_6;
		break;
	case 10:
		mode = ADC12138_MODE_ACQUISITION_TIME_10;
		break;
	case 18:
		mode = ADC12138_MODE_ACQUISITION_TIME_18;
		break;
	case 34:
		mode = ADC12138_MODE_ACQUISITION_TIME_34;
		break;
	default:
		return -EINVAL;
	}

	return adc12138_mode_programming(adc, mode, &trash, 1);
}

static irqreturn_t adc12138_trigger_handler(int irq, void *p)
{
	struct iio_poll_func *pf = p;
	struct iio_dev *indio_dev = pf->indio_dev;
	struct adc12138 *adc = iio_priv(indio_dev);
	__be16 data[20] = { }; /* 16x 2 bytes ADC data + 8 bytes timestamp */
	__be16 trash;
	int ret;
	int scan_index;
	int i = 0;

	mutex_lock(&adc->lock);

	for_each_set_bit(scan_index, indio_dev->active_scan_mask,
			 indio_dev->masklength) {
		const struct iio_chan_spec *scan_chan =
				&indio_dev->channels[scan_index];

		reinit_completion(&adc->complete);

		ret = adc12138_start_and_read_conv(adc, scan_chan,
						   i ? &data[i - 1] : &trash);
		if (ret) {
			dev_warn(&adc->spi->dev,
				 "failed to start conversion\n");
			goto out;
		}

		ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
		if (ret) {
			dev_warn(&adc->spi->dev, "wait eoc timeout\n");
			goto out;
		}

		i++;
	}

	if (i) {
		ret = adc12138_read_conv_data(adc, &data[i - 1]);
		if (ret) {
			dev_warn(&adc->spi->dev,
				 "failed to get conversion data\n");
			goto out;
		}
	}

	iio_push_to_buffers_with_timestamp(indio_dev, data,
					   iio_get_time_ns(indio_dev));
out:
	mutex_unlock(&adc->lock);

	iio_trigger_notify_done(indio_dev->trig);

	return IRQ_HANDLED;
}

static irqreturn_t adc12138_eoc_handler(int irq, void *p)
{
	struct iio_dev *indio_dev = p;
	struct adc12138 *adc = iio_priv(indio_dev);

	complete(&adc->complete);

	return IRQ_HANDLED;
}

static int adc12138_probe(struct spi_device *spi)
{
	struct iio_dev *indio_dev;
	struct adc12138 *adc;
	int ret;

	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
	if (!indio_dev)
		return -ENOMEM;

	adc = iio_priv(indio_dev);
	adc->spi = spi;
	adc->id = spi_get_device_id(spi)->driver_data;
	mutex_init(&adc->lock);
	init_completion(&adc->complete);

	indio_dev->name = spi_get_device_id(spi)->name;
	indio_dev->dev.parent = &spi->dev;
	indio_dev->info = &adc12138_info;
	indio_dev->modes = INDIO_DIRECT_MODE;

	switch (adc->id) {
	case adc12130:
	case adc12132:
		indio_dev->channels = adc12132_channels;
		indio_dev->num_channels = ARRAY_SIZE(adc12132_channels);
		break;
	case adc12138:
		indio_dev->channels = adc12138_channels;
		indio_dev->num_channels = ARRAY_SIZE(adc12138_channels);
		break;
	default:
		return -EINVAL;
	}

	ret = of_property_read_u32(spi->dev.of_node, "ti,acquisition-time",
				   &adc->acquisition_time);
	if (ret)
		adc->acquisition_time = 10;

	adc->cclk = devm_clk_get(&spi->dev, NULL);
	if (IS_ERR(adc->cclk))
		return PTR_ERR(adc->cclk);

	adc->vref_p = devm_regulator_get(&spi->dev, "vref-p");
	if (IS_ERR(adc->vref_p))
		return PTR_ERR(adc->vref_p);

	adc->vref_n = devm_regulator_get_optional(&spi->dev, "vref-n");
	if (IS_ERR(adc->vref_n)) {
		/*
		 * Assume vref_n is 0V if an optional regulator is not
		 * specified, otherwise return the error code.
		 */
		ret = PTR_ERR(adc->vref_n);
		if (ret != -ENODEV)
			return ret;
	}

	ret = devm_request_irq(&spi->dev, spi->irq, adc12138_eoc_handler,
			       IRQF_TRIGGER_RISING, indio_dev->name, indio_dev);
	if (ret)
		return ret;

	ret = clk_prepare_enable(adc->cclk);
	if (ret)
		return ret;

	ret = regulator_enable(adc->vref_p);
	if (ret)
		goto err_clk_disable;

	if (!IS_ERR(adc->vref_n)) {
		ret = regulator_enable(adc->vref_n);
		if (ret)
			goto err_vref_p_disable;
	}

	ret = adc12138_init(adc);
	if (ret)
		goto err_vref_n_disable;

	spi_set_drvdata(spi, indio_dev);

	ret = iio_triggered_buffer_setup(indio_dev, NULL,
					 adc12138_trigger_handler, NULL);
	if (ret)
		goto err_vref_n_disable;

	ret = iio_device_register(indio_dev);
	if (ret)
		goto err_buffer_cleanup;

	return 0;
err_buffer_cleanup:
	iio_triggered_buffer_cleanup(indio_dev);
err_vref_n_disable:
	if (!IS_ERR(adc->vref_n))
		regulator_disable(adc->vref_n);
err_vref_p_disable:
	regulator_disable(adc->vref_p);
err_clk_disable:
	clk_disable_unprepare(adc->cclk);

	return ret;
}

static int adc12138_remove(struct spi_device *spi)
{
	struct iio_dev *indio_dev = spi_get_drvdata(spi);
	struct adc12138 *adc = iio_priv(indio_dev);

	iio_device_unregister(indio_dev);
	iio_triggered_buffer_cleanup(indio_dev);
	if (!IS_ERR(adc->vref_n))
		regulator_disable(adc->vref_n);
	regulator_disable(adc->vref_p);
	clk_disable_unprepare(adc->cclk);

	return 0;
}

#ifdef CONFIG_OF

static const struct of_device_id adc12138_dt_ids[] = {
	{ .compatible = "ti,adc12130", },
	{ .compatible = "ti,adc12132", },
	{ .compatible = "ti,adc12138", },
	{}
};
MODULE_DEVICE_TABLE(of, adc12138_dt_ids);

#endif

static const struct spi_device_id adc12138_id[] = {
	{ "adc12130", adc12130 },
	{ "adc12132", adc12132 },
	{ "adc12138", adc12138 },
	{}
};
MODULE_DEVICE_TABLE(spi, adc12138_id);

static struct spi_driver adc12138_driver = {
	.driver = {
		.name = "adc12138",
		.of_match_table = of_match_ptr(adc12138_dt_ids),
	},
	.probe = adc12138_probe,
	.remove = adc12138_remove,
	.id_table = adc12138_id,
};
module_spi_driver(adc12138_driver);

MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
MODULE_DESCRIPTION("ADC12130/ADC12132/ADC12138 driver");
MODULE_LICENSE("GPL v2");
Commit	Line	Data
50a6edb1 AM	1	/*
	2	* ADC12130/ADC12132/ADC12138 12-bit plus sign ADC driver
	3	*
	4	* Copyright (c) 2016 Akinobu Mita <akinobu.mita@gmail.com>
	5	*
	6	* This file is subject to the terms and conditions of version 2 of
	7	* the GNU General Public License. See the file COPYING in the main
	8	* directory of this archive for more details.
	9	*
	10	* Datasheet: http://www.ti.com/lit/ds/symlink/adc12138.pdf
	11	*/
	12
	13	#include <linux/module.h>
	14	#include <linux/interrupt.h>
	15	#include <linux/completion.h>
	16	#include <linux/clk.h>
	17	#include <linux/spi/spi.h>
	18	#include <linux/iio/iio.h>
	19	#include <linux/iio/buffer.h>
	20	#include <linux/iio/trigger.h>
	21	#include <linux/iio/triggered_buffer.h>
	22	#include <linux/iio/trigger_consumer.h>
	23	#include <linux/regulator/consumer.h>
	24
	25	#define ADC12138_MODE_AUTO_CAL 0x08
	26	#define ADC12138_MODE_READ_STATUS 0x0c
	27	#define ADC12138_MODE_ACQUISITION_TIME_6 0x0e
	28	#define ADC12138_MODE_ACQUISITION_TIME_10 0x4e
	29	#define ADC12138_MODE_ACQUISITION_TIME_18 0x8e
	30	#define ADC12138_MODE_ACQUISITION_TIME_34 0xce
	31
	32	#define ADC12138_STATUS_CAL BIT(6)
	33
	34	enum {
	35	adc12130,
	36	adc12132,
	37	adc12138,
	38	};
	39
	40	struct adc12138 {
	41	struct spi_device *spi;
	42	unsigned int id;
	43	/* conversion clock */
	44	struct clk *cclk;
	45	/* positive analog voltage reference */
	46	struct regulator *vref_p;
	47	/* negative analog voltage reference */
	48	struct regulator *vref_n;
	49	struct mutex lock;
	50	struct completion complete;
	51	/* The number of cclk periods for the S/H's acquisition time */
	52	unsigned int acquisition_time;
	53
	54	u8 tx_buf[2] ____cacheline_aligned;
	55	u8 rx_buf[2];
	56	};
	57
	58	#define ADC12138_VOLTAGE_CHANNEL(chan) \
	59	{ \
	60	.type = IIO_VOLTAGE, \
	61	.indexed = 1, \
	62	.channel = chan, \
	63	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
	64	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
65	\| BIT(IIO_CHAN_INFO_OFFSET), \
66	.scan_index = chan, \
67	.scan_type = { \
68	.sign = 's', \
69	.realbits = 13, \
70	.storagebits = 16, \
71	.shift = 3, \
72	.endianness = IIO_BE, \
73	}, \
74	}
75
76	#define ADC12138_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si) \
77	{ \
78	.type = IIO_VOLTAGE, \
79	.indexed = 1, \
80	.channel = (chan1), \
81	.channel2 = (chan2), \
82	.differential = 1, \
83	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
84	.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
85	\| BIT(IIO_CHAN_INFO_OFFSET), \
86	.scan_index = si, \
87	.scan_type = { \
88	.sign = 's', \
89	.realbits = 13, \
90	.storagebits = 16, \
91	.shift = 3, \
92	.endianness = IIO_BE, \
93	}, \
94	}
95
96	static const struct iio_chan_spec adc12132_channels[] = {
97	ADC12138_VOLTAGE_CHANNEL(0),
98	ADC12138_VOLTAGE_CHANNEL(1),
99	ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 2),
100	ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 3),
101	IIO_CHAN_SOFT_TIMESTAMP(4),
102	};
103
104	static const struct iio_chan_spec adc12138_channels[] = {
105	ADC12138_VOLTAGE_CHANNEL(0),
106	ADC12138_VOLTAGE_CHANNEL(1),
107	ADC12138_VOLTAGE_CHANNEL(2),
108	ADC12138_VOLTAGE_CHANNEL(3),
109	ADC12138_VOLTAGE_CHANNEL(4),
110	ADC12138_VOLTAGE_CHANNEL(5),
111	ADC12138_VOLTAGE_CHANNEL(6),
112	ADC12138_VOLTAGE_CHANNEL(7),
113	ADC12138_VOLTAGE_CHANNEL_DIFF(0, 1, 8),
114	ADC12138_VOLTAGE_CHANNEL_DIFF(1, 0, 9),
115	ADC12138_VOLTAGE_CHANNEL_DIFF(2, 3, 10),
116	ADC12138_VOLTAGE_CHANNEL_DIFF(3, 2, 11),
117	ADC12138_VOLTAGE_CHANNEL_DIFF(4, 5, 12),
118	ADC12138_VOLTAGE_CHANNEL_DIFF(5, 4, 13),
119	ADC12138_VOLTAGE_CHANNEL_DIFF(6, 7, 14),
120	ADC12138_VOLTAGE_CHANNEL_DIFF(7, 6, 15),
121	IIO_CHAN_SOFT_TIMESTAMP(16),
122	};
123
124	static int adc12138_mode_programming(struct adc12138 *adc, u8 mode,
125	void *rx_buf, int len)
126	{
127	struct spi_transfer xfer = {
128	.tx_buf = adc->tx_buf,
129	.rx_buf = adc->rx_buf,
130	.len = len,
131	};
132	int ret;
133
134	/* Skip unused bits for ADC12130 and ADC12132 */
135	if (adc->id != adc12138)
136	mode = (mode & 0xc0) \| ((mode & 0x0f) << 2);
137
138	adc->tx_buf[0] = mode;
139
140	ret = spi_sync_transfer(adc->spi, &xfer, 1);
141	if (ret)
142	return ret;
143
144	memcpy(rx_buf, adc->rx_buf, len);
145
146	return 0;
147	}
148
149	static int adc12138_read_status(struct adc12138 *adc)
150	{
151	u8 rx_buf[2];
152	int ret;
153
154	ret = adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
155	rx_buf, 2);
156	if (ret)
157	return ret;
158
159	return (rx_buf[0] << 1) \| (rx_buf[1] >> 7);
160	}
161
162	static int __adc12138_start_conv(struct adc12138 *adc,
163	struct iio_chan_spec const *channel,
164	void *data, int len)
165
166	{
59dba8fa	167	static const u8 ch_to_mux[] = { 0, 4, 1, 5, 2, 6, 3, 7 };
50a6edb1 AM	168	u8 mode = (ch_to_mux[channel->channel] << 4) \|
	169	(channel->differential ? 0 : 0x80);
	170
	171	return adc12138_mode_programming(adc, mode, data, len);
	172	}
	173
	174	static int adc12138_start_conv(struct adc12138 *adc,
	175	struct iio_chan_spec const *channel)
	176	{
	177	u8 trash;
	178
	179	return __adc12138_start_conv(adc, channel, &trash, 1);
	180	}
	181
	182	static int adc12138_start_and_read_conv(struct adc12138 *adc,
	183	struct iio_chan_spec const *channel,
	184	__be16 *data)
	185	{
	186	return __adc12138_start_conv(adc, channel, data, 2);
	187	}
	188
	189	static int adc12138_read_conv_data(struct adc12138 adc, __be16 value)
	190	{
	191	/* Issue a read status instruction and read previous conversion data */
	192	return adc12138_mode_programming(adc, ADC12138_MODE_READ_STATUS,
	193	value, sizeof(*value));
	194	}
	195
	196	static int adc12138_wait_eoc(struct adc12138 *adc, unsigned long timeout)
	197	{
	198	if (!wait_for_completion_timeout(&adc->complete, timeout))
	199	return -ETIMEDOUT;
	200
	201	return 0;
	202	}
	203
	204	static int adc12138_adc_conversion(struct adc12138 *adc,
	205	struct iio_chan_spec const *channel,
	206	__be16 *value)
	207	{
	208	int ret;
	209
	210	reinit_completion(&adc->complete);
	211
	212	ret = adc12138_start_conv(adc, channel);
	213	if (ret)
	214	return ret;
	215
	216	ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
	217	if (ret)
	218	return ret;
	219
	220	return adc12138_read_conv_data(adc, value);
	221	}
	222
	223	static int adc12138_read_raw(struct iio_dev *iio,
	224	struct iio_chan_spec const channel, int value,
	225	int *shift, long mask)
	226	{
	227	struct adc12138 *adc = iio_priv(iio);
	228	int ret;
	229	__be16 data;
	230
	231	switch (mask) {
232	case IIO_CHAN_INFO_RAW:
233	mutex_lock(&adc->lock);
234	ret = adc12138_adc_conversion(adc, channel, &data);
235	mutex_unlock(&adc->lock);
236	if (ret)
237	return ret;
238
239	*value = sign_extend32(be16_to_cpu(data) >> 3, 12);
240
241	return IIO_VAL_INT;
242	case IIO_CHAN_INFO_SCALE:
243	ret = regulator_get_voltage(adc->vref_p);
244	if (ret < 0)
245	return ret;
246	*value = ret;
247
248	if (!IS_ERR(adc->vref_n)) {
249	ret = regulator_get_voltage(adc->vref_n);
250	if (ret < 0)
251	return ret;
252	*value -= ret;
253	}
254
255	/* convert regulator output voltage to mV */
256	*value /= 1000;
257	*shift = channel->scan_type.realbits - 1;
258
259	return IIO_VAL_FRACTIONAL_LOG2;
260	case IIO_CHAN_INFO_OFFSET:
261	if (!IS_ERR(adc->vref_n)) {
262	*value = regulator_get_voltage(adc->vref_n);
263	if (*value < 0)
264	return *value;
265	} else {
266	*value = 0;
267	}
268
269	/* convert regulator output voltage to mV */
270	*value /= 1000;
271
272	return IIO_VAL_INT;
273	}
274
275	return -EINVAL;
276	}
277
278	static const struct iio_info adc12138_info = {
279	.read_raw = adc12138_read_raw,
50a6edb1 AM	280	};
	281
	282	static int adc12138_init(struct adc12138 *adc)
	283	{
	284	int ret;
	285	int status;
	286	u8 mode;
	287	u8 trash;
	288
	289	reinit_completion(&adc->complete);
	290
	291	ret = adc12138_mode_programming(adc, ADC12138_MODE_AUTO_CAL, &trash, 1);
	292	if (ret)
	293	return ret;
	294
	295	/* data output at this time has no significance */
	296	status = adc12138_read_status(adc);
	297	if (status < 0)
	298	return status;
	299
	300	adc12138_wait_eoc(adc, msecs_to_jiffies(100));
	301
	302	status = adc12138_read_status(adc);
	303	if (status & ADC12138_STATUS_CAL) {
	304	dev_warn(&adc->spi->dev,
	305	"Auto Cal sequence is still in progress: %#x\n",
	306	status);
	307	return -EIO;
	308	}
	309
	310	switch (adc->acquisition_time) {
	311	case 6:
	312	mode = ADC12138_MODE_ACQUISITION_TIME_6;
	313	break;
	314	case 10:
	315	mode = ADC12138_MODE_ACQUISITION_TIME_10;
	316	break;
	317	case 18:
	318	mode = ADC12138_MODE_ACQUISITION_TIME_18;
	319	break;
	320	case 34:
	321	mode = ADC12138_MODE_ACQUISITION_TIME_34;
	322	break;
	323	default:
	324	return -EINVAL;
	325	}
	326
	327	return adc12138_mode_programming(adc, mode, &trash, 1);
	328	}
	329
	330	static irqreturn_t adc12138_trigger_handler(int irq, void *p)
	331	{
	332	struct iio_poll_func *pf = p;
	333	struct iio_dev *indio_dev = pf->indio_dev;
	334	struct adc12138 *adc = iio_priv(indio_dev);
	335	__be16 data[20] = { }; /* 16x 2 bytes ADC data + 8 bytes timestamp */
	336	__be16 trash;
	337	int ret;
	338	int scan_index;
	339	int i = 0;
	340
	341	mutex_lock(&adc->lock);
	342
	343	for_each_set_bit(scan_index, indio_dev->active_scan_mask,
344	indio_dev->masklength) {
345	const struct iio_chan_spec *scan_chan =
346	&indio_dev->channels[scan_index];
347
348	reinit_completion(&adc->complete);
349
350	ret = adc12138_start_and_read_conv(adc, scan_chan,
351	i ? &data[i - 1] : &trash);
352	if (ret) {
353	dev_warn(&adc->spi->dev,
354	"failed to start conversion\n");
355	goto out;
356	}
357
358	ret = adc12138_wait_eoc(adc, msecs_to_jiffies(100));
359	if (ret) {
360	dev_warn(&adc->spi->dev, "wait eoc timeout\n");
361	goto out;
362	}
363
364	i++;
365	}
366
367	if (i) {
368	ret = adc12138_read_conv_data(adc, &data[i - 1]);
369	if (ret) {
370	dev_warn(&adc->spi->dev,
371	"failed to get conversion data\n");
372	goto out;
373	}
374	}
375
376	iio_push_to_buffers_with_timestamp(indio_dev, data,
377	iio_get_time_ns(indio_dev));
378	out:
379	mutex_unlock(&adc->lock);
380
381	iio_trigger_notify_done(indio_dev->trig);
382
383	return IRQ_HANDLED;
384	}
385
386	static irqreturn_t adc12138_eoc_handler(int irq, void *p)
387	{
388	struct iio_dev *indio_dev = p;
389	struct adc12138 *adc = iio_priv(indio_dev);
390
391	complete(&adc->complete);
392
393	return IRQ_HANDLED;
394	}
395
396	static int adc12138_probe(struct spi_device *spi)
397	{
398	struct iio_dev *indio_dev;
399	struct adc12138 *adc;
400	int ret;
401
402	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));
403	if (!indio_dev)
404	return -ENOMEM;
405
406	adc = iio_priv(indio_dev);
407	adc->spi = spi;
408	adc->id = spi_get_device_id(spi)->driver_data;
409	mutex_init(&adc->lock);
410	init_completion(&adc->complete);
411
412	indio_dev->name = spi_get_device_id(spi)->name;
413	indio_dev->dev.parent = &spi->dev;
414	indio_dev->info = &adc12138_info;
415	indio_dev->modes = INDIO_DIRECT_MODE;
416
417	switch (adc->id) {
418	case adc12130:
419	case adc12132:
420	indio_dev->channels = adc12132_channels;
421	indio_dev->num_channels = ARRAY_SIZE(adc12132_channels);
422	break;
423	case adc12138:
424	indio_dev->channels = adc12138_channels;
425	indio_dev->num_channels = ARRAY_SIZE(adc12138_channels);
426	break;
427	default:
428	return -EINVAL;
429	}
430
431	ret = of_property_read_u32(spi->dev.of_node, "ti,acquisition-time",
432	&adc->acquisition_time);
433	if (ret)
434	adc->acquisition_time = 10;
435
436	adc->cclk = devm_clk_get(&spi->dev, NULL);
437	if (IS_ERR(adc->cclk))
438	return PTR_ERR(adc->cclk);
439
440	adc->vref_p = devm_regulator_get(&spi->dev, "vref-p");
441	if (IS_ERR(adc->vref_p))
442	return PTR_ERR(adc->vref_p);
443
444	adc->vref_n = devm_regulator_get_optional(&spi->dev, "vref-n");
445	if (IS_ERR(adc->vref_n)) {
446	/*
447	* Assume vref_n is 0V if an optional regulator is not
448	* specified, otherwise return the error code.
449	*/
450	ret = PTR_ERR(adc->vref_n);
451	if (ret != -ENODEV)
452	return ret;
453	}
454
455	ret = devm_request_irq(&spi->dev, spi->irq, adc12138_eoc_handler,
456	IRQF_TRIGGER_RISING, indio_dev->name, indio_dev);
457	if (ret)
458	return ret;
459
460	ret = clk_prepare_enable(adc->cclk);
461	if (ret)
462	return ret;
463
464	ret = regulator_enable(adc->vref_p);
465	if (ret)
466	goto err_clk_disable;
467
468	if (!IS_ERR(adc->vref_n)) {
469	ret = regulator_enable(adc->vref_n);
470	if (ret)
471	goto err_vref_p_disable;
472	}
473
474	ret = adc12138_init(adc);
475	if (ret)
476	goto err_vref_n_disable;
477
478	spi_set_drvdata(spi, indio_dev);
479
480	ret = iio_triggered_buffer_setup(indio_dev, NULL,
481	adc12138_trigger_handler, NULL);
482	if (ret)
483	goto err_vref_n_disable;
484
485	ret = iio_device_register(indio_dev);
486	if (ret)
487	goto err_buffer_cleanup;
488
489	return 0;
490	err_buffer_cleanup:
491	iio_triggered_buffer_cleanup(indio_dev);
492	err_vref_n_disable:
493	if (!IS_ERR(adc->vref_n))
494	regulator_disable(adc->vref_n);
495	err_vref_p_disable:
496	regulator_disable(adc->vref_p);
497	err_clk_disable:
498	clk_disable_unprepare(adc->cclk);
499
500	return ret;
501	}
502
503	static int adc12138_remove(struct spi_device *spi)
504	{
505	struct iio_dev *indio_dev = spi_get_drvdata(spi);
506	struct adc12138 *adc = iio_priv(indio_dev);
507
508	iio_device_unregister(indio_dev);
509	iio_triggered_buffer_cleanup(indio_dev);
510	if (!IS_ERR(adc->vref_n))
511	regulator_disable(adc->vref_n);
512	regulator_disable(adc->vref_p);
513	clk_disable_unprepare(adc->cclk);
514
515	return 0;
516	}
517
518	#ifdef CONFIG_OF
519
520	static const struct of_device_id adc12138_dt_ids[] = {
521	{ .compatible = "ti,adc12130", },
522	{ .compatible = "ti,adc12132", },
523	{ .compatible = "ti,adc12138", },
524	{}
525	};
526	MODULE_DEVICE_TABLE(of, adc12138_dt_ids);
527
528	#endif
529
530	static const struct spi_device_id adc12138_id[] = {
531	{ "adc12130", adc12130 },
532	{ "adc12132", adc12132 },
533	{ "adc12138", adc12138 },
534	{}
535	};
536	MODULE_DEVICE_TABLE(spi, adc12138_id);
537
538	static struct spi_driver adc12138_driver = {
539	.driver = {
540	.name = "adc12138",
541	.of_match_table = of_match_ptr(adc12138_dt_ids),
542	},
543	.probe = adc12138_probe,
544	.remove = adc12138_remove,
545	.id_table = adc12138_id,
546	};
547	module_spi_driver(adc12138_driver);
548
549	MODULE_AUTHOR("Akinobu Mita <akinobu.mita@gmail.com>");
550	MODULE_DESCRIPTION("ADC12130/ADC12132/ADC12138 driver");
551	MODULE_LICENSE("GPL v2");