1 // SPDX-License-Identifier: GPL-2.0
3  * IIO driver for Texas Instruments ADS7924 ADC, 12-bit, 4-Channels, I2C
8  * based on iio/adc/ti-ads1015.c
23 #include <linux/regulator/consumer.h>
98  * The power-up time is allowed to elapse whenever the device has been shutdown
99  * in idle mode. Power-up time can allow external circuits, such as an
103  * If a power-up time is not required, set the bits to '0' to effectively bypass.
105 #define ADS7924_PWRUPTIME_US 0 /* Bypass (0us). */
135 	struct regulator *vref_reg;
137 	/* GPIO descriptor for device hard-reset pin. */
147 	 * Set to true when the ADC is switched to the continuous-conversion
148 	 * mode and exits from a power-down state. This flag is used to avoid
198 	if (chan->channel < 0 || chan->channel >= ADS7924_CHANNELS)  in ads7924_get_adc_result()
199 		return -EINVAL;  in ads7924_get_adc_result()
201 	if (data->conv_invalid) {  in ads7924_get_adc_result()
205 		/* Allow 10% for internal clock inaccuracy. */  in ads7924_get_adc_result()
208 		data->conv_invalid = false;  in ads7924_get_adc_result()
211 	ret = regmap_raw_read(data->regmap, ADS7924_AUTO_INCREMENT_BIT |  in ads7924_get_adc_result()
212 			      chan->address, &be_val, sizeof(be_val));  in ads7924_get_adc_result()
230 		mutex_lock(&data->lock);  in ads7924_read_raw()
232 		mutex_unlock(&data->lock);  in ads7924_read_raw()
238 		vref_uv = regulator_get_voltage(data->vref_reg);  in ads7924_read_raw()
246 		return -EINVAL;  in ads7924_read_raw()
279 		return -EINVAL;  in ads7924_get_channels_config()
288 	struct device *dev = data->dev;  in ads7924_set_conv_mode()
299 		ret = regmap_update_bits(data->regmap, ADS7924_MODECNTRL_REG,  in ads7924_set_conv_mode()
311 	ret = regmap_update_bits(data->regmap, ADS7924_MODECNTRL_REG,  in ads7924_set_conv_mode()
324 	if (data->reset_gpio) {  in ads7924_reset()
325 		gpiod_set_value(data->reset_gpio, 1); /* Assert. */  in ads7924_reset()
328 		gpiod_set_value(data->reset_gpio, 0); /* Deassert. */  in ads7924_reset()
336 	return regmap_write(data->regmap, ADS7924_RESET_REG, 0b10101010);  in ads7924_reset()
353 	struct device *dev = &client->dev;  in ads7924_probe()
356 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));  in ads7924_probe()
358 		return dev_err_probe(dev, -ENOMEM,  in ads7924_probe()
363 	data->dev = dev;  in ads7924_probe()
366 	data->reset_gpio = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW);  in ads7924_probe()
367 	if (IS_ERR(data->reset_gpio))  in ads7924_probe()
368 		return dev_err_probe(dev, PTR_ERR(data->reset_gpio),  in ads7924_probe()
371 	mutex_init(&data->lock);  in ads7924_probe()
373 	indio_dev->name = "ads7924";  in ads7924_probe()
374 	indio_dev->modes = INDIO_DIRECT_MODE;  in ads7924_probe()
376 	indio_dev->channels = ads7924_channels;  in ads7924_probe()
377 	indio_dev->num_channels = ARRAY_SIZE(ads7924_channels);  in ads7924_probe()
378 	indio_dev->info = &ads7924_info;  in ads7924_probe()
385 	data->regmap = devm_regmap_init_i2c(client, &ads7924_regmap_config);  in ads7924_probe()
386 	if (IS_ERR(data->regmap))  in ads7924_probe()
387 		return dev_err_probe(dev, PTR_ERR(data->regmap),  in ads7924_probe()
390 	data->vref_reg = devm_regulator_get(dev, "vref");  in ads7924_probe()
391 	if (IS_ERR(data->vref_reg))  in ads7924_probe()
392 		return dev_err_probe(dev, PTR_ERR(data->vref_reg),  in ads7924_probe()
393 				     "failed to get vref regulator\n");  in ads7924_probe()
395 	ret = regulator_enable(data->vref_reg);  in ads7924_probe()
398 				     "failed to enable regulator\n");  in ads7924_probe()
400 	ret = devm_add_action_or_reset(dev, ads7924_reg_disable, data->vref_reg);  in ads7924_probe()
403 				     "failed to add regulator disable action\n");  in ads7924_probe()
421 	ret = regmap_update_bits(data->regmap, ADS7924_ACQCONFIG_REG,  in ads7924_probe()
428 	/* Disable power-up time. */  in ads7924_probe()
429 	ret = regmap_update_bits(data->regmap, ADS7924_PWRCONFIG_REG,  in ads7924_probe()
434 				     "failed to configure power-up time\n");  in ads7924_probe()
436 	data->conv_invalid = true;  in ads7924_probe()