1 // SPDX-License-Identifier: GPL-2.0-only
3  * ADC0831/ADC0832/ADC0834/ADC0838 8-bit ADC driver
7  * Datasheet: https://www.ti.com/lit/ds/symlink/adc0832-n.pdf
33 	 * Max size needed: 16x 1 byte ADC data + 8 bytes timestamp
34 	 * May be shorter if not all channels are enabled subject
120 static int adc0831_adc_conversion(struct adc0832 *adc)  in adc0831_adc_conversion()  argument
122 	struct spi_device *spi = adc->spi;  in adc0831_adc_conversion()
125 	ret = spi_read(spi, &adc->rx_buf, 2);  in adc0831_adc_conversion()
130 	 * Skip TRI-STATE and a leading zero  in adc0831_adc_conversion()
132 	return (adc->rx_buf[0] << 2 & 0xff) | (adc->rx_buf[1] >> 6);  in adc0831_adc_conversion()
135 static int adc0832_adc_conversion(struct adc0832 *adc, int channel,  in adc0832_adc_conversion()  argument
138 	struct spi_device *spi = adc->spi;  in adc0832_adc_conversion()
140 		.tx_buf = adc->tx_buf,  in adc0832_adc_conversion()
141 		.rx_buf = adc->rx_buf,  in adc0832_adc_conversion()
146 	if (!adc->mux_bits)  in adc0832_adc_conversion()
147 		return adc0831_adc_conversion(adc);  in adc0832_adc_conversion()
150 	adc->tx_buf[0] = 1 << (adc->mux_bits + 1);  in adc0832_adc_conversion()
151 	/* single-ended or differential */  in adc0832_adc_conversion()
152 	adc->tx_buf[0] |= differential ? 0 : (1 << adc->mux_bits);  in adc0832_adc_conversion()
154 	adc->tx_buf[0] |= (channel % 2) << (adc->mux_bits - 1);  in adc0832_adc_conversion()
156 	if (adc->mux_bits > 1)  in adc0832_adc_conversion()
157 		adc->tx_buf[0] |= channel / 2;  in adc0832_adc_conversion()
159 	/* align Data output BIT7 (MSB) to 8-bit boundary */  in adc0832_adc_conversion()
160 	adc->tx_buf[0] <<= 1;  in adc0832_adc_conversion()
166 	return adc->rx_buf[1];  in adc0832_adc_conversion()
173 	struct adc0832 *adc = iio_priv(iio);  in adc0832_read_raw()  local
177 		mutex_lock(&adc->lock);  in adc0832_read_raw()
178 		*value = adc0832_adc_conversion(adc, channel->channel,  in adc0832_read_raw()
179 						channel->differential);  in adc0832_read_raw()
180 		mutex_unlock(&adc->lock);  in adc0832_read_raw()
186 		*value = regulator_get_voltage(adc->reg);  in adc0832_read_raw()
197 	return -EINVAL;  in adc0832_read_raw()
207 	struct iio_dev *indio_dev = pf->indio_dev;  in adc0832_trigger_handler()
208 	struct adc0832 *adc = iio_priv(indio_dev);  in adc0832_trigger_handler()  local
212 	mutex_lock(&adc->lock);  in adc0832_trigger_handler()
216 				&indio_dev->channels[scan_index];  in adc0832_trigger_handler()
217 		int ret = adc0832_adc_conversion(adc, scan_chan->channel,  in adc0832_trigger_handler()
218 						 scan_chan->differential);  in adc0832_trigger_handler()
220 			dev_warn(&adc->spi->dev,  in adc0832_trigger_handler()
225 		adc->data[i] = ret;  in adc0832_trigger_handler()
228 	iio_push_to_buffers_with_timestamp(indio_dev, adc->data,  in adc0832_trigger_handler()
231 	mutex_unlock(&adc->lock);  in adc0832_trigger_handler()
233 	iio_trigger_notify_done(indio_dev->trig);  in adc0832_trigger_handler()
246 	struct adc0832 *adc;  in adc0832_probe()  local
249 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));  in adc0832_probe()
251 		return -ENOMEM;  in adc0832_probe()
253 	adc = iio_priv(indio_dev);  in adc0832_probe()
254 	adc->spi = spi;  in adc0832_probe()
255 	mutex_init(&adc->lock);  in adc0832_probe()
257 	indio_dev->name = spi_get_device_id(spi)->name;  in adc0832_probe()
258 	indio_dev->info = &adc0832_info;  in adc0832_probe()
259 	indio_dev->modes = INDIO_DIRECT_MODE;  in adc0832_probe()
261 	switch (spi_get_device_id(spi)->driver_data) {  in adc0832_probe()
263 		adc->mux_bits = 0;  in adc0832_probe()
264 		indio_dev->channels = adc0831_channels;  in adc0832_probe()
265 		indio_dev->num_channels = ARRAY_SIZE(adc0831_channels);  in adc0832_probe()
268 		adc->mux_bits = 1;  in adc0832_probe()
269 		indio_dev->channels = adc0832_channels;  in adc0832_probe()
270 		indio_dev->num_channels = ARRAY_SIZE(adc0832_channels);  in adc0832_probe()
273 		adc->mux_bits = 2;  in adc0832_probe()
274 		indio_dev->channels = adc0834_channels;  in adc0832_probe()
275 		indio_dev->num_channels = ARRAY_SIZE(adc0834_channels);  in adc0832_probe()
278 		adc->mux_bits = 3;  in adc0832_probe()
279 		indio_dev->channels = adc0838_channels;  in adc0832_probe()
280 		indio_dev->num_channels = ARRAY_SIZE(adc0838_channels);  in adc0832_probe()
283 		return -EINVAL;  in adc0832_probe()
286 	adc->reg = devm_regulator_get(&spi->dev, "vref");  in adc0832_probe()
287 	if (IS_ERR(adc->reg))  in adc0832_probe()
288 		return PTR_ERR(adc->reg);  in adc0832_probe()
290 	ret = regulator_enable(adc->reg);  in adc0832_probe()
294 	ret = devm_add_action_or_reset(&spi->dev, adc0832_reg_disable,  in adc0832_probe()
295 				       adc->reg);  in adc0832_probe()
299 	ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, NULL,  in adc0832_probe()
304 	return devm_iio_device_register(&spi->dev, indio_dev);  in adc0832_probe()