1 // SPDX-License-Identifier: GPL-2.0+
3  * ADS8344 16-bit 8-Channel ADC driver
17 #define ADS8344_START BIT(7)
19 #define ADS8344_CHANNEL(channel) ((channel) << 4)  argument
26 	 * Lock protecting access to adc->tx_buff and rx_buff,
39 		.channel = chan,					\
49 		.channel = (chan1),					\
65 	ADS8344_VOLTAGE_CHANNEL(7, 7),
69 	ADS8344_VOLTAGE_CHANNEL_DIFF(6, 7, 11),
73 	ADS8344_VOLTAGE_CHANNEL_DIFF(7, 6, 15),
76 static int ads8344_adc_conversion(struct ads8344 *adc, int channel,  in ads8344_adc_conversion()  argument
79 	struct spi_device *spi = adc->spi;  in ads8344_adc_conversion()
82 	adc->tx_buf = ADS8344_START;  in ads8344_adc_conversion()
84 		adc->tx_buf |= ADS8344_SINGLE_END;  in ads8344_adc_conversion()
85 	adc->tx_buf |= ADS8344_CHANNEL(channel);  in ads8344_adc_conversion()
86 	adc->tx_buf |= ADS8344_CLOCK_INTERNAL;  in ads8344_adc_conversion()
88 	ret = spi_write(spi, &adc->tx_buf, 1);  in ads8344_adc_conversion()
94 	ret = spi_read(spi, adc->rx_buf, sizeof(adc->rx_buf));  in ads8344_adc_conversion()
98 	return adc->rx_buf[0] << 9 | adc->rx_buf[1] << 1 | adc->rx_buf[2] >> 7;  in ads8344_adc_conversion()
102 			    struct iio_chan_spec const *channel, int *value,  in ads8344_read_raw()  argument
109 		mutex_lock(&adc->lock);  in ads8344_read_raw()
110 		*value = ads8344_adc_conversion(adc, channel->address,  in ads8344_read_raw()
111 						channel->differential);  in ads8344_read_raw()
112 		mutex_unlock(&adc->lock);  in ads8344_read_raw()
118 		*value = regulator_get_voltage(adc->reg);  in ads8344_read_raw()
128 		return -EINVAL;  in ads8344_read_raw()
147 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));  in ads8344_probe()
149 		return -ENOMEM;  in ads8344_probe()
152 	adc->spi = spi;  in ads8344_probe()
153 	mutex_init(&adc->lock);  in ads8344_probe()
155 	indio_dev->name = dev_name(&spi->dev);  in ads8344_probe()
156 	indio_dev->info = &ads8344_info;  in ads8344_probe()
157 	indio_dev->modes = INDIO_DIRECT_MODE;  in ads8344_probe()
158 	indio_dev->channels = ads8344_channels;  in ads8344_probe()
159 	indio_dev->num_channels = ARRAY_SIZE(ads8344_channels);  in ads8344_probe()
161 	adc->reg = devm_regulator_get(&spi->dev, "vref");  in ads8344_probe()
162 	if (IS_ERR(adc->reg))  in ads8344_probe()
163 		return PTR_ERR(adc->reg);  in ads8344_probe()
165 	ret = regulator_enable(adc->reg);  in ads8344_probe()
169 	ret = devm_add_action_or_reset(&spi->dev, ads8344_reg_disable, adc->reg);  in ads8344_probe()
173 	return devm_iio_device_register(&spi->dev, indio_dev);  in ads8344_probe()