1 // SPDX-License-Identifier: GPL-2.0-only
14  * ------------
20  * ------------
23  * ------------
30  * https://ww1.microchip.com/downloads/en/DeviceDoc/21293C.pdf  mcp3001
31  * https://ww1.microchip.com/downloads/en/DeviceDoc/21294E.pdf  mcp3002
32  * https://ww1.microchip.com/downloads/en/DeviceDoc/21295d.pdf  mcp3004/08
33  * http://ww1.microchip.com/downloads/en/DeviceDoc/21290D.pdf  mcp3201
34  * http://ww1.microchip.com/downloads/en/DeviceDoc/21034D.pdf  mcp3202
35  * http://ww1.microchip.com/downloads/en/DeviceDoc/21298c.pdf  mcp3204/08
36  * https://ww1.microchip.com/downloads/en/DeviceDoc/21700E.pdf  mcp3301
37  * http://ww1.microchip.com/downloads/en/DeviceDoc/21950D.pdf  mcp3550/1/3
72  * struct mcp320x - Microchip SPI ADC instance
78  * @reg: regulator generating Vref
81  * @tx_buf: buffer for @transfer[0] (not used on single-channel converters)
116 		return -EINVAL;  in mcp320x_channel_to_tx_data()
125 	if (adc->chip_info->conv_time) {  in mcp320x_adc_conversion()
126 		ret = spi_sync(adc->spi, &adc->start_conv_msg);  in mcp320x_adc_conversion()
130 		usleep_range(adc->chip_info->conv_time,  in mcp320x_adc_conversion()
131 			     adc->chip_info->conv_time + 100);  in mcp320x_adc_conversion()
134 	memset(&adc->rx_buf, 0, sizeof(adc->rx_buf));  in mcp320x_adc_conversion()
135 	if (adc->chip_info->num_channels > 1)  in mcp320x_adc_conversion()
136 		adc->tx_buf = mcp320x_channel_to_tx_data(device_index, channel,  in mcp320x_adc_conversion()
139 	ret = spi_sync(adc->spi, &adc->msg);  in mcp320x_adc_conversion()
145 		*val = (adc->rx_buf[0] << 5 | adc->rx_buf[1] >> 3);  in mcp320x_adc_conversion()
150 		*val = (adc->rx_buf[0] << 2 | adc->rx_buf[1] >> 6);  in mcp320x_adc_conversion()
153 		*val = (adc->rx_buf[0] << 7 | adc->rx_buf[1] >> 1);  in mcp320x_adc_conversion()
158 		*val = (adc->rx_buf[0] << 4 | adc->rx_buf[1] >> 4);  in mcp320x_adc_conversion()
161 		*val = sign_extend32((adc->rx_buf[0] & 0x1f) << 8  in mcp320x_adc_conversion()
162 				    | adc->rx_buf[1], 12);  in mcp320x_adc_conversion()
168 		u32 raw = be32_to_cpup((__be32 *)adc->rx_buf);  in mcp320x_adc_conversion()
170 		if (!(adc->spi->mode & SPI_CPOL))  in mcp320x_adc_conversion()
174 		 * If the input is within -vref and vref, bit 21 is the sign.  in mcp320x_adc_conversion()
180 			return -EIO; /* cannot have overrange AND underrange */  in mcp320x_adc_conversion()
190 		return -EINVAL;  in mcp320x_adc_conversion()
199 	int ret = -EINVAL;  in mcp320x_read_raw()
202 	mutex_lock(&adc->lock);  in mcp320x_read_raw()
204 	device_index = spi_get_device_id(adc->spi)->driver_data;  in mcp320x_read_raw()
208 		ret = mcp320x_adc_conversion(adc, channel->address,  in mcp320x_read_raw()
209 			channel->differential, device_index, val);  in mcp320x_read_raw()
211 			goto out;  in mcp320x_read_raw()
217 		ret = regulator_get_voltage(adc->reg);  in mcp320x_read_raw()
219 			goto out;  in mcp320x_read_raw()
223 		*val2 = adc->chip_info->resolution;  in mcp320x_read_raw()
228 out:  in mcp320x_read_raw()
229 	mutex_unlock(&adc->lock);  in mcp320x_read_raw()
386 	indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc));  in mcp320x_probe()
388 		return -ENOMEM;  in mcp320x_probe()
391 	adc->spi = spi;  in mcp320x_probe()
393 	indio_dev->name = spi_get_device_id(spi)->name;  in mcp320x_probe()
394 	indio_dev->modes = INDIO_DIRECT_MODE;  in mcp320x_probe()
395 	indio_dev->info = &mcp320x_info;  in mcp320x_probe()
397 	device_index = spi_get_device_id(spi)->driver_data;  in mcp320x_probe()
399 	indio_dev->channels = chip_info->channels;  in mcp320x_probe()
400 	indio_dev->num_channels = chip_info->num_channels;  in mcp320x_probe()
402 	adc->chip_info = chip_info;  in mcp320x_probe()
404 	adc->transfer[0].tx_buf = &adc->tx_buf;  in mcp320x_probe()
405 	adc->transfer[0].len = sizeof(adc->tx_buf);  in mcp320x_probe()
406 	adc->transfer[1].rx_buf = adc->rx_buf;  in mcp320x_probe()
407 	adc->transfer[1].len = DIV_ROUND_UP(chip_info->resolution, 8);  in mcp320x_probe()
409 	if (chip_info->num_channels == 1)  in mcp320x_probe()
410 		/* single-channel converters are rx only (no MOSI pin) */  in mcp320x_probe()
411 		spi_message_init_with_transfers(&adc->msg,  in mcp320x_probe()
412 						&adc->transfer[1], 1);  in mcp320x_probe()
414 		spi_message_init_with_transfers(&adc->msg, adc->transfer,  in mcp320x_probe()
415 						ARRAY_SIZE(adc->transfer));  in mcp320x_probe()
423 		if (!(spi->mode & SPI_CPOL))  in mcp320x_probe()
424 			adc->transfer[1].len++;  in mcp320x_probe()
427 		adc->start_conv_transfer.delay.value = 8;  in mcp320x_probe()
428 		adc->start_conv_transfer.delay.unit = SPI_DELAY_UNIT_USECS;  in mcp320x_probe()
429 		spi_message_init_with_transfers(&adc->start_conv_msg,  in mcp320x_probe()
430 						&adc->start_conv_transfer, 1);  in mcp320x_probe()
435 		 * Sometimes it fails to wake from shutdown and clocks out  in mcp320x_probe()
444 	adc->reg = devm_regulator_get(&spi->dev, "vref");  in mcp320x_probe()
445 	if (IS_ERR(adc->reg))  in mcp320x_probe()
446 		return PTR_ERR(adc->reg);  in mcp320x_probe()
448 	ret = regulator_enable(adc->reg);  in mcp320x_probe()
452 	ret = devm_add_action_or_reset(&spi->dev, mcp320x_regulator_disable, adc->reg);  in mcp320x_probe()
456 	mutex_init(&adc->lock);  in mcp320x_probe()
458 	return devm_iio_device_register(&spi->dev, indio_dev);  in mcp320x_probe()
471 	{ .compatible = "microchip,mcp3550-50" },
472 	{ .compatible = "microchip,mcp3550-60" },
489 	{ "mcp3550-50", mcp3550_50 },
490 	{ "mcp3550-60", mcp3550_60 },