// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (C) 2013 Oskar Andero * Copyright (C) 2014 Rose Technology * Allan Bendorff Jensen * Soren Andersen * * Driver for following ADC chips from Microchip Technology's: * 10 Bit converter * MCP3001 * MCP3002 * MCP3004 * MCP3008 * ------------ * 12 bit converter * MCP3201 * MCP3202 * MCP3204 * MCP3208 * ------------ * 13 bit converter * MCP3301 * ------------ * 22 bit converter * MCP3550 * MCP3551 * MCP3553 * * Datasheet can be found here: * http://ww1.microchip.com/downloads/en/DeviceDoc/21293C.pdf mcp3001 * http://ww1.microchip.com/downloads/en/DeviceDoc/21294E.pdf mcp3002 * http://ww1.microchip.com/downloads/en/DeviceDoc/21295d.pdf mcp3004/08 * http://ww1.microchip.com/downloads/en/DeviceDoc/21290D.pdf mcp3201 * http://ww1.microchip.com/downloads/en/DeviceDoc/21034D.pdf mcp3202 * http://ww1.microchip.com/downloads/en/DeviceDoc/21298c.pdf mcp3204/08 * http://ww1.microchip.com/downloads/en/DeviceDoc/21700E.pdf mcp3301 * http://ww1.microchip.com/downloads/en/DeviceDoc/21950D.pdf mcp3550/1/3 */ #include #include #include #include #include #include enum { mcp3001, mcp3002, mcp3004, mcp3008, mcp3201, mcp3202, mcp3204, mcp3208, mcp3301, mcp3550_50, mcp3550_60, mcp3551, mcp3553, }; struct mcp320x_chip_info { const struct iio_chan_spec *channels; unsigned int num_channels; unsigned int resolution; unsigned int conv_time; /* usec */ }; /** * struct mcp320x - Microchip SPI ADC instance * @spi: SPI slave (parent of the IIO device) * @msg: SPI message to select a channel and receive a value from the ADC * @transfer: SPI transfers used by @msg * @start_conv_msg: SPI message to start a conversion by briefly asserting CS * @start_conv_transfer: SPI transfer used by @start_conv_msg * @reg: regulator generating Vref * @lock: protects read sequences * @chip_info: ADC properties * @tx_buf: buffer for @transfer[0] (not used on single-channel converters) * @rx_buf: buffer for @transfer[1] */ struct mcp320x { struct spi_device *spi; struct spi_message msg; struct spi_transfer transfer[2]; struct spi_message start_conv_msg; struct spi_transfer start_conv_transfer; struct regulator *reg; struct mutex lock; const struct mcp320x_chip_info *chip_info; u8 tx_buf ____cacheline_aligned; u8 rx_buf[4]; }; static int mcp320x_channel_to_tx_data(int device_index, const unsigned int channel, bool differential) { int start_bit = 1; switch (device_index) { case mcp3002: case mcp3202: return ((start_bit << 4) | (!differential << 3) | (channel << 2)); case mcp3004: case mcp3204: case mcp3008: case mcp3208: return ((start_bit << 6) | (!differential << 5) | (channel << 2)); default: return -EINVAL; } } static int mcp320x_adc_conversion(struct mcp320x *adc, u8 channel, bool differential, int device_index, int *val) { int ret; if (adc->chip_info->conv_time) { ret = spi_sync(adc->spi, &adc->start_conv_msg); if (ret < 0) return ret; usleep_range(adc->chip_info->conv_time, adc->chip_info->conv_time + 100); } memset(&adc->rx_buf, 0, sizeof(adc->rx_buf)); if (adc->chip_info->num_channels > 1) adc->tx_buf = mcp320x_channel_to_tx_data(device_index, channel, differential); ret = spi_sync(adc->spi, &adc->msg); if (ret < 0) return ret; switch (device_index) { case mcp3001: *val = (adc->rx_buf[0] << 5 | adc->rx_buf[1] >> 3); return 0; case mcp3002: case mcp3004: case mcp3008: *val = (adc->rx_buf[0] << 2 | adc->rx_buf[1] >> 6); return 0; case mcp3201: *val = (adc->rx_buf[0] << 7 | adc->rx_buf[1] >> 1); return 0; case mcp3202: case mcp3204: case mcp3208: *val = (adc->rx_buf[0] << 4 | adc->rx_buf[1] >> 4); return 0; case mcp3301: *val = sign_extend32((adc->rx_buf[0] & 0x1f) << 8 | adc->rx_buf[1], 12); return 0; case mcp3550_50: case mcp3550_60: case mcp3551: case mcp3553: { u32 raw = be32_to_cpup((__be32 *)adc->rx_buf); if (!(adc->spi->mode & SPI_CPOL)) raw <<= 1; /* strip Data Ready bit in SPI mode 0,0 */ /* * If the input is within -vref and vref, bit 21 is the sign. * Up to 12% overrange or underrange are allowed, in which case * bit 23 is the sign and bit 0 to 21 is the value. */ raw >>= 8; if (raw & BIT(22) && raw & BIT(23)) return -EIO; /* cannot have overrange AND underrange */ else if (raw & BIT(22)) raw &= ~BIT(22); /* overrange */ else if (raw & BIT(23) || raw & BIT(21)) raw |= GENMASK(31, 22); /* underrange or negative */ *val = (s32)raw; return 0; } default: return -EINVAL; } } static int mcp320x_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *channel, int *val, int *val2, long mask) { struct mcp320x *adc = iio_priv(indio_dev); int ret = -EINVAL; int device_index = 0; mutex_lock(&adc->lock); device_index = spi_get_device_id(adc->spi)->driver_data; switch (mask) { case IIO_CHAN_INFO_RAW: ret = mcp320x_adc_conversion(adc, channel->address, channel->differential, device_index, val); if (ret < 0) goto out; ret = IIO_VAL_INT; break; case IIO_CHAN_INFO_SCALE: ret = regulator_get_voltage(adc->reg); if (ret < 0) goto out; /* convert regulator output voltage to mV */ *val = ret / 1000; *val2 = adc->chip_info->resolution; ret = IIO_VAL_FRACTIONAL_LOG2; break; } out: mutex_unlock(&adc->lock); return ret; } #define MCP320X_VOLTAGE_CHANNEL(num) \ { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .channel = (num), \ .address = (num), \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ } #define MCP320X_VOLTAGE_CHANNEL_DIFF(chan1, chan2) \ { \ .type = IIO_VOLTAGE, \ .indexed = 1, \ .channel = (chan1), \ .channel2 = (chan2), \ .address = (chan1), \ .differential = 1, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \ } static const struct iio_chan_spec mcp3201_channels[] = { MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1), }; static const struct iio_chan_spec mcp3202_channels[] = { MCP320X_VOLTAGE_CHANNEL(0), MCP320X_VOLTAGE_CHANNEL(1), MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1), MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0), }; static const struct iio_chan_spec mcp3204_channels[] = { MCP320X_VOLTAGE_CHANNEL(0), MCP320X_VOLTAGE_CHANNEL(1), MCP320X_VOLTAGE_CHANNEL(2), MCP320X_VOLTAGE_CHANNEL(3), MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1), MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0), MCP320X_VOLTAGE_CHANNEL_DIFF(2, 3), MCP320X_VOLTAGE_CHANNEL_DIFF(3, 2), }; static const struct iio_chan_spec mcp3208_channels[] = { MCP320X_VOLTAGE_CHANNEL(0), MCP320X_VOLTAGE_CHANNEL(1), MCP320X_VOLTAGE_CHANNEL(2), MCP320X_VOLTAGE_CHANNEL(3), MCP320X_VOLTAGE_CHANNEL(4), MCP320X_VOLTAGE_CHANNEL(5), MCP320X_VOLTAGE_CHANNEL(6), MCP320X_VOLTAGE_CHANNEL(7), MCP320X_VOLTAGE_CHANNEL_DIFF(0, 1), MCP320X_VOLTAGE_CHANNEL_DIFF(1, 0), MCP320X_VOLTAGE_CHANNEL_DIFF(2, 3), MCP320X_VOLTAGE_CHANNEL_DIFF(3, 2), MCP320X_VOLTAGE_CHANNEL_DIFF(4, 5), MCP320X_VOLTAGE_CHANNEL_DIFF(5, 4), MCP320X_VOLTAGE_CHANNEL_DIFF(6, 7), MCP320X_VOLTAGE_CHANNEL_DIFF(7, 6), }; static const struct iio_info mcp320x_info = { .read_raw = mcp320x_read_raw, }; static const struct mcp320x_chip_info mcp320x_chip_infos[] = { [mcp3001] = { .channels = mcp3201_channels, .num_channels = ARRAY_SIZE(mcp3201_channels), .resolution = 10 }, [mcp3002] = { .channels = mcp3202_channels, .num_channels = ARRAY_SIZE(mcp3202_channels), .resolution = 10 }, [mcp3004] = { .channels = mcp3204_channels, .num_channels = ARRAY_SIZE(mcp3204_channels), .resolution = 10 }, [mcp3008] = { .channels = mcp3208_channels, .num_channels = ARRAY_SIZE(mcp3208_channels), .resolution = 10 }, [mcp3201] = { .channels = mcp3201_channels, .num_channels = ARRAY_SIZE(mcp3201_channels), .resolution = 12 }, [mcp3202] = { .channels = mcp3202_channels, .num_channels = ARRAY_SIZE(mcp3202_channels), .resolution = 12 }, [mcp3204] = { .channels = mcp3204_channels, .num_channels = ARRAY_SIZE(mcp3204_channels), .resolution = 12 }, [mcp3208] = { .channels = mcp3208_channels, .num_channels = ARRAY_SIZE(mcp3208_channels), .resolution = 12 }, [mcp3301] = { .channels = mcp3201_channels, .num_channels = ARRAY_SIZE(mcp3201_channels), .resolution = 13 }, [mcp3550_50] = { .channels = mcp3201_channels, .num_channels = ARRAY_SIZE(mcp3201_channels), .resolution = 21, /* 2% max deviation + 144 clock periods to exit shutdown */ .conv_time = 80000 * 1.02 + 144000 / 102.4, }, [mcp3550_60] = { .channels = mcp3201_channels, .num_channels = ARRAY_SIZE(mcp3201_channels), .resolution = 21, .conv_time = 66670 * 1.02 + 144000 / 122.88, }, [mcp3551] = { .channels = mcp3201_channels, .num_channels = ARRAY_SIZE(mcp3201_channels), .resolution = 21, .conv_time = 73100 * 1.02 + 144000 / 112.64, }, [mcp3553] = { .channels = mcp3201_channels, .num_channels = ARRAY_SIZE(mcp3201_channels), .resolution = 21, .conv_time = 16670 * 1.02 + 144000 / 122.88, }, }; static int mcp320x_probe(struct spi_device *spi) { struct iio_dev *indio_dev; struct mcp320x *adc; const struct mcp320x_chip_info *chip_info; int ret, device_index; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*adc)); if (!indio_dev) return -ENOMEM; adc = iio_priv(indio_dev); adc->spi = spi; indio_dev->dev.parent = &spi->dev; indio_dev->dev.of_node = spi->dev.of_node; indio_dev->name = spi_get_device_id(spi)->name; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->info = &mcp320x_info; spi_set_drvdata(spi, indio_dev); device_index = spi_get_device_id(spi)->driver_data; chip_info = &mcp320x_chip_infos[device_index]; indio_dev->channels = chip_info->channels; indio_dev->num_channels = chip_info->num_channels; adc->chip_info = chip_info; adc->transfer[0].tx_buf = &adc->tx_buf; adc->transfer[0].len = sizeof(adc->tx_buf); adc->transfer[1].rx_buf = adc->rx_buf; adc->transfer[1].len = DIV_ROUND_UP(chip_info->resolution, 8); if (chip_info->num_channels == 1) /* single-channel converters are rx only (no MOSI pin) */ spi_message_init_with_transfers(&adc->msg, &adc->transfer[1], 1); else spi_message_init_with_transfers(&adc->msg, adc->transfer, ARRAY_SIZE(adc->transfer)); switch (device_index) { case mcp3550_50: case mcp3550_60: case mcp3551: case mcp3553: /* rx len increases from 24 to 25 bit in SPI mode 0,0 */ if (!(spi->mode & SPI_CPOL)) adc->transfer[1].len++; /* conversions are started by asserting CS pin for 8 usec */ adc->start_conv_transfer.delay.value = 8; adc->start_conv_transfer.delay.unit = SPI_DELAY_UNIT_USECS; spi_message_init_with_transfers(&adc->start_conv_msg, &adc->start_conv_transfer, 1); /* * If CS was previously kept low (continuous conversion mode) * and then changed to high, the chip is in shutdown. * Sometimes it fails to wake from shutdown and clocks out * only 0xffffff. The magic sequence of performing two * conversions without delay between them resets the chip * and ensures all subsequent conversions succeed. */ mcp320x_adc_conversion(adc, 0, 1, device_index, &ret); mcp320x_adc_conversion(adc, 0, 1, device_index, &ret); } adc->reg = devm_regulator_get(&spi->dev, "vref"); if (IS_ERR(adc->reg)) return PTR_ERR(adc->reg); ret = regulator_enable(adc->reg); if (ret < 0) return ret; mutex_init(&adc->lock); ret = iio_device_register(indio_dev); if (ret < 0) goto reg_disable; return 0; reg_disable: regulator_disable(adc->reg); return ret; } static int mcp320x_remove(struct spi_device *spi) { struct iio_dev *indio_dev = spi_get_drvdata(spi); struct mcp320x *adc = iio_priv(indio_dev); iio_device_unregister(indio_dev); regulator_disable(adc->reg); return 0; } #if defined(CONFIG_OF) static const struct of_device_id mcp320x_dt_ids[] = { /* NOTE: The use of compatibles with no vendor prefix is deprecated. */ { .compatible = "mcp3001" }, { .compatible = "mcp3002" }, { .compatible = "mcp3004" }, { .compatible = "mcp3008" }, { .compatible = "mcp3201" }, { .compatible = "mcp3202" }, { .compatible = "mcp3204" }, { .compatible = "mcp3208" }, { .compatible = "mcp3301" }, { .compatible = "microchip,mcp3001" }, { .compatible = "microchip,mcp3002" }, { .compatible = "microchip,mcp3004" }, { .compatible = "microchip,mcp3008" }, { .compatible = "microchip,mcp3201" }, { .compatible = "microchip,mcp3202" }, { .compatible = "microchip,mcp3204" }, { .compatible = "microchip,mcp3208" }, { .compatible = "microchip,mcp3301" }, { .compatible = "microchip,mcp3550-50" }, { .compatible = "microchip,mcp3550-60" }, { .compatible = "microchip,mcp3551" }, { .compatible = "microchip,mcp3553" }, { } }; MODULE_DEVICE_TABLE(of, mcp320x_dt_ids); #endif static const struct spi_device_id mcp320x_id[] = { { "mcp3001", mcp3001 }, { "mcp3002", mcp3002 }, { "mcp3004", mcp3004 }, { "mcp3008", mcp3008 }, { "mcp3201", mcp3201 }, { "mcp3202", mcp3202 }, { "mcp3204", mcp3204 }, { "mcp3208", mcp3208 }, { "mcp3301", mcp3301 }, { "mcp3550-50", mcp3550_50 }, { "mcp3550-60", mcp3550_60 }, { "mcp3551", mcp3551 }, { "mcp3553", mcp3553 }, { } }; MODULE_DEVICE_TABLE(spi, mcp320x_id); static struct spi_driver mcp320x_driver = { .driver = { .name = "mcp320x", .of_match_table = of_match_ptr(mcp320x_dt_ids), }, .probe = mcp320x_probe, .remove = mcp320x_remove, .id_table = mcp320x_id, }; module_spi_driver(mcp320x_driver); MODULE_AUTHOR("Oskar Andero "); MODULE_DESCRIPTION("Microchip Technology MCP3x01/02/04/08 and MCP3550/1/3"); MODULE_LICENSE("GPL v2");