gehc-pmc-adc.c

  1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * The GE HealthCare PMC ADC is a 16-Channel (Voltage and current), 16-Bit
  4 * ADC with an I2C Interface.
  5 *
  6 * Copyright (C) 2024, GE HealthCare
  7 *
  8 * Authors:
  9 * Herve Codina <herve.codina@bootlin.com>
 10 */
 11#include <dt-bindings/iio/adc/gehc,pmc-adc.h>
 12#include <linux/bitops.h>
 13#include <linux/clk.h>
 14#include <linux/i2c.h>
 15#include <linux/iio/iio.h>
 16#include <linux/module.h>
 17#include <linux/regulator/consumer.h>
 18#include <linux/slab.h>
 19
 20struct pmc_adc {
 21	struct i2c_client *client;
 22};
 23
 24#define PMC_ADC_CMD_REQUEST_PROTOCOL_VERSION	0x01
 25#define PMC_ADC_CMD_READ_VOLTAGE(_ch)		(0x10 | (_ch))
 26#define PMC_ADC_CMD_READ_CURRENT(_ch)		(0x20 | (_ch))
 27
 28#define PMC_ADC_VOLTAGE_CHANNEL(_ch, _ds_name) {			\
 29	.type = IIO_VOLTAGE,						\
 30	.indexed = 1,							\
 31	.channel = (_ch),						\
 32	.address = PMC_ADC_CMD_READ_VOLTAGE(_ch),			\
 33	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),		\
 34	.datasheet_name = (_ds_name),					\
 35}
 36
 37#define PMC_ADC_CURRENT_CHANNEL(_ch, _ds_name) {			\
 38	.type = IIO_CURRENT,						\
 39	.indexed = 1,							\
 40	.channel = (_ch),						\
 41	.address = PMC_ADC_CMD_READ_CURRENT(_ch),			\
 42	.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),		\
 43	.datasheet_name = (_ds_name),					\
 44}
 45
 46static const struct iio_chan_spec pmc_adc_channels[] = {
 47	PMC_ADC_VOLTAGE_CHANNEL(0, "CH0_V"),
 48	PMC_ADC_VOLTAGE_CHANNEL(1, "CH1_V"),
 49	PMC_ADC_VOLTAGE_CHANNEL(2, "CH2_V"),
 50	PMC_ADC_VOLTAGE_CHANNEL(3, "CH3_V"),
 51	PMC_ADC_VOLTAGE_CHANNEL(4, "CH4_V"),
 52	PMC_ADC_VOLTAGE_CHANNEL(5, "CH5_V"),
 53	PMC_ADC_VOLTAGE_CHANNEL(6, "CH6_V"),
 54	PMC_ADC_VOLTAGE_CHANNEL(7, "CH7_V"),
 55	PMC_ADC_VOLTAGE_CHANNEL(8, "CH8_V"),
 56	PMC_ADC_VOLTAGE_CHANNEL(9, "CH9_V"),
 57	PMC_ADC_VOLTAGE_CHANNEL(10, "CH10_V"),
 58	PMC_ADC_VOLTAGE_CHANNEL(11, "CH11_V"),
 59	PMC_ADC_VOLTAGE_CHANNEL(12, "CH12_V"),
 60	PMC_ADC_VOLTAGE_CHANNEL(13, "CH13_V"),
 61	PMC_ADC_VOLTAGE_CHANNEL(14, "CH14_V"),
 62	PMC_ADC_VOLTAGE_CHANNEL(15, "CH15_V"),
 63
 64	PMC_ADC_CURRENT_CHANNEL(0, "CH0_I"),
 65	PMC_ADC_CURRENT_CHANNEL(1, "CH1_I"),
 66	PMC_ADC_CURRENT_CHANNEL(2, "CH2_I"),
 67	PMC_ADC_CURRENT_CHANNEL(3, "CH3_I"),
 68	PMC_ADC_CURRENT_CHANNEL(4, "CH4_I"),
 69	PMC_ADC_CURRENT_CHANNEL(5, "CH5_I"),
 70	PMC_ADC_CURRENT_CHANNEL(6, "CH6_I"),
 71	PMC_ADC_CURRENT_CHANNEL(7, "CH7_I"),
 72	PMC_ADC_CURRENT_CHANNEL(8, "CH8_I"),
 73	PMC_ADC_CURRENT_CHANNEL(9, "CH9_I"),
 74	PMC_ADC_CURRENT_CHANNEL(10, "CH10_I"),
 75	PMC_ADC_CURRENT_CHANNEL(11, "CH11_I"),
 76	PMC_ADC_CURRENT_CHANNEL(12, "CH12_I"),
 77	PMC_ADC_CURRENT_CHANNEL(13, "CH13_I"),
 78	PMC_ADC_CURRENT_CHANNEL(14, "CH14_I"),
 79	PMC_ADC_CURRENT_CHANNEL(15, "CH15_I"),
 80};
 81
 82static int pmc_adc_read_raw_ch(struct pmc_adc *pmc_adc, u8 cmd, int *val)
 83{
 84	s32 ret;
 85
 86	ret = i2c_smbus_read_word_swapped(pmc_adc->client, cmd);
 87	if (ret < 0) {
 88		dev_err(&pmc_adc->client->dev, "i2c read word failed (%d)\n", ret);
 89		return ret;
 90	}
 91
 92	*val = sign_extend32(ret, 15);
 93	return 0;
 94}
 95
 96static int pmc_adc_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan,
 97			    int *val, int *val2, long mask)
 98{
 99	struct pmc_adc *pmc_adc = iio_priv(indio_dev);
100	int ret;
101
102	switch (mask) {
103	case IIO_CHAN_INFO_PROCESSED:
104		/* Values are directly read in mV or mA */
105		ret = pmc_adc_read_raw_ch(pmc_adc, chan->address, val);
106		if (ret)
107			return ret;
108		return IIO_VAL_INT;
109	}
110
111	return -EINVAL;
112}
113
114static int pmc_adc_fwnode_xlate(struct iio_dev *indio_dev,
115				const struct fwnode_reference_args *iiospec)
116{
117	enum iio_chan_type expected_type;
118	unsigned int i;
119
120	/*
121	 * args[0]: Acquisition type (i.e. voltage or current)
122	 * args[1]: PMC ADC channel number
123	 */
124	if (iiospec->nargs != 2)
125		return -EINVAL;
126
127	switch (iiospec->args[0]) {
128	case GEHC_PMC_ADC_VOLTAGE:
129		expected_type = IIO_VOLTAGE;
130		break;
131	case GEHC_PMC_ADC_CURRENT:
132		expected_type = IIO_CURRENT;
133		break;
134	default:
135		dev_err(&indio_dev->dev, "Invalid channel type %llu\n",
136			iiospec->args[0]);
137		return -EINVAL;
138	}
139
140	for (i = 0; i < indio_dev->num_channels; i++)
141		if (indio_dev->channels[i].type == expected_type &&
142		    indio_dev->channels[i].channel == iiospec->args[1])
143			return i;
144
145	dev_err(&indio_dev->dev, "Invalid channel type %llu number %llu\n",
146		iiospec->args[0], iiospec->args[1]);
147	return -EINVAL;
148}
149
150static const struct iio_info pmc_adc_info = {
151	.read_raw = pmc_adc_read_raw,
152	.fwnode_xlate = pmc_adc_fwnode_xlate,
153};
154
155static const char *const pmc_adc_regulator_names[] = {
156	"vdd",
157	"vdda",
158	"vddio",
159	"vref",
160};
161
162static int pmc_adc_probe(struct i2c_client *client)
163{
164	struct iio_dev *indio_dev;
165	struct pmc_adc *pmc_adc;
166	struct clk *clk;
167	s32 val;
168	int ret;
169
170	ret = devm_regulator_bulk_get_enable(&client->dev, ARRAY_SIZE(pmc_adc_regulator_names),
171					     pmc_adc_regulator_names);
172	if (ret)
173		return dev_err_probe(&client->dev, ret, "Failed to get regulators\n");
174
175	clk = devm_clk_get_optional_enabled(&client->dev, "osc");
176	if (IS_ERR(clk))
177		return dev_err_probe(&client->dev, PTR_ERR(clk), "Failed to get osc clock\n");
178
179	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*pmc_adc));
180	if (!indio_dev)
181		return -ENOMEM;
182
183	pmc_adc = iio_priv(indio_dev);
184	pmc_adc->client = client;
185
186	val = i2c_smbus_read_byte_data(pmc_adc->client, PMC_ADC_CMD_REQUEST_PROTOCOL_VERSION);
187	if (val < 0)
188		return dev_err_probe(&client->dev, val, "Failed to get protocol version\n");
189
190	if (val != 0x01)
191		return dev_err_probe(&client->dev, -EINVAL,
192				     "Unsupported protocol version 0x%02x\n", val);
193
194	indio_dev->name = "pmc_adc";
195	indio_dev->info = &pmc_adc_info;
196	indio_dev->modes = INDIO_DIRECT_MODE;
197	indio_dev->channels = pmc_adc_channels;
198	indio_dev->num_channels = ARRAY_SIZE(pmc_adc_channels);
199
200	return devm_iio_device_register(&client->dev, indio_dev);
201}
202
203static const struct of_device_id pmc_adc_of_match[] = {
204	{ .compatible = "gehc,pmc-adc"},
205	{ }
206};
207MODULE_DEVICE_TABLE(of, pmc_adc_of_match);
208
209static const struct i2c_device_id pmc_adc_id_table[] = {
210	{ "pmc-adc" },
211	{ }
212};
213MODULE_DEVICE_TABLE(i2c, pmc_adc_id_table);
214
215static struct i2c_driver pmc_adc_i2c_driver = {
216	.driver  = {
217		.name = "pmc-adc",
218		.of_match_table = pmc_adc_of_match,
219	},
220	.id_table = pmc_adc_id_table,
221	.probe  = pmc_adc_probe,
222};
223
224module_i2c_driver(pmc_adc_i2c_driver);
225
226MODULE_AUTHOR("Herve Codina <herve.codina@bootlin.com>");
227MODULE_DESCRIPTION("GE HealthCare PMC ADC driver");
228MODULE_LICENSE("GPL");