diff options
Diffstat (limited to 'drivers/iio/adc/ad7606_spi.c')
| -rw-r--r-- | drivers/iio/adc/ad7606_spi.c | 364 |
1 files changed, 364 insertions, 0 deletions
diff --git a/drivers/iio/adc/ad7606_spi.c b/drivers/iio/adc/ad7606_spi.c new file mode 100644 index 000000000..29945ad07 --- /dev/null +++ b/drivers/iio/adc/ad7606_spi.c @@ -0,0 +1,364 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * AD7606 SPI ADC driver + * + * Copyright 2011 Analog Devices Inc. + */ + +#include <linux/module.h> +#include <linux/spi/spi.h> +#include <linux/types.h> +#include <linux/err.h> + +#include <linux/iio/iio.h> +#include "ad7606.h" + +#define MAX_SPI_FREQ_HZ 23500000 /* VDRIVE above 4.75 V */ + +#define AD7616_CONFIGURATION_REGISTER 0x02 +#define AD7616_OS_MASK GENMASK(4, 2) +#define AD7616_BURST_MODE BIT(6) +#define AD7616_SEQEN_MODE BIT(5) +#define AD7616_RANGE_CH_A_ADDR_OFF 0x04 +#define AD7616_RANGE_CH_B_ADDR_OFF 0x06 +/* + * Range of channels from a group are stored in 2 registers. + * 0, 1, 2, 3 in a register followed by 4, 5, 6, 7 in second register. + * For channels from second group(8-15) the order is the same, only with + * an offset of 2 for register address. + */ +#define AD7616_RANGE_CH_ADDR(ch) ((ch) >> 2) +/* The range of the channel is stored in 2 bits */ +#define AD7616_RANGE_CH_MSK(ch) (0b11 << (((ch) & 0b11) * 2)) +#define AD7616_RANGE_CH_MODE(ch, mode) ((mode) << ((((ch) & 0b11)) * 2)) + +#define AD7606_CONFIGURATION_REGISTER 0x02 +#define AD7606_SINGLE_DOUT 0x00 + +/* + * Range for AD7606B channels are stored in registers starting with address 0x3. + * Each register stores range for 2 channels(4 bits per channel). + */ +#define AD7606_RANGE_CH_MSK(ch) (GENMASK(3, 0) << (4 * ((ch) & 0x1))) +#define AD7606_RANGE_CH_MODE(ch, mode) \ + ((GENMASK(3, 0) & mode) << (4 * ((ch) & 0x1))) +#define AD7606_RANGE_CH_ADDR(ch) (0x03 + ((ch) >> 1)) +#define AD7606_OS_MODE 0x08 + +static const struct iio_chan_spec ad7616_sw_channels[] = { + IIO_CHAN_SOFT_TIMESTAMP(16), + AD7616_CHANNEL(0), + AD7616_CHANNEL(1), + AD7616_CHANNEL(2), + AD7616_CHANNEL(3), + AD7616_CHANNEL(4), + AD7616_CHANNEL(5), + AD7616_CHANNEL(6), + AD7616_CHANNEL(7), + AD7616_CHANNEL(8), + AD7616_CHANNEL(9), + AD7616_CHANNEL(10), + AD7616_CHANNEL(11), + AD7616_CHANNEL(12), + AD7616_CHANNEL(13), + AD7616_CHANNEL(14), + AD7616_CHANNEL(15), +}; + +static const struct iio_chan_spec ad7606b_sw_channels[] = { + IIO_CHAN_SOFT_TIMESTAMP(8), + AD7616_CHANNEL(0), + AD7616_CHANNEL(1), + AD7616_CHANNEL(2), + AD7616_CHANNEL(3), + AD7616_CHANNEL(4), + AD7616_CHANNEL(5), + AD7616_CHANNEL(6), + AD7616_CHANNEL(7), +}; + +static const unsigned int ad7606B_oversampling_avail[9] = { + 1, 2, 4, 8, 16, 32, 64, 128, 256 +}; + +static u16 ad7616_spi_rd_wr_cmd(int addr, char isWriteOp) +{ + /* + * The address of register consist of one w/r bit + * 6 bits of address followed by one reserved bit. + */ + return ((addr & 0x7F) << 1) | ((isWriteOp & 0x1) << 7); +} + +static u16 ad7606B_spi_rd_wr_cmd(int addr, char is_write_op) +{ + /* + * The address of register consists of one bit which + * specifies a read command placed in bit 6, followed by + * 6 bits of address. + */ + return (addr & 0x3F) | (((~is_write_op) & 0x1) << 6); +} + +static int ad7606_spi_read_block(struct device *dev, + int count, void *buf) +{ + struct spi_device *spi = to_spi_device(dev); + int i, ret; + unsigned short *data = buf; + __be16 *bdata = buf; + + ret = spi_read(spi, buf, count * 2); + if (ret < 0) { + dev_err(&spi->dev, "SPI read error\n"); + return ret; + } + + for (i = 0; i < count; i++) + data[i] = be16_to_cpu(bdata[i]); + + return 0; +} + +static int ad7606_spi_reg_read(struct ad7606_state *st, unsigned int addr) +{ + struct spi_device *spi = to_spi_device(st->dev); + struct spi_transfer t[] = { + { + .tx_buf = &st->d16[0], + .len = 2, + .cs_change = 0, + }, { + .rx_buf = &st->d16[1], + .len = 2, + }, + }; + int ret; + + st->d16[0] = cpu_to_be16(st->bops->rd_wr_cmd(addr, 0) << 8); + + ret = spi_sync_transfer(spi, t, ARRAY_SIZE(t)); + if (ret < 0) + return ret; + + return be16_to_cpu(st->d16[1]); +} + +static int ad7606_spi_reg_write(struct ad7606_state *st, + unsigned int addr, + unsigned int val) +{ + struct spi_device *spi = to_spi_device(st->dev); + + st->d16[0] = cpu_to_be16((st->bops->rd_wr_cmd(addr, 1) << 8) | + (val & 0x1FF)); + + return spi_write(spi, &st->d16[0], sizeof(st->d16[0])); +} + +static int ad7606_spi_write_mask(struct ad7606_state *st, + unsigned int addr, + unsigned long mask, + unsigned int val) +{ + int readval; + + readval = st->bops->reg_read(st, addr); + if (readval < 0) + return readval; + + readval &= ~mask; + readval |= val; + + return st->bops->reg_write(st, addr, readval); +} + +static int ad7616_write_scale_sw(struct iio_dev *indio_dev, int ch, int val) +{ + struct ad7606_state *st = iio_priv(indio_dev); + unsigned int ch_addr, mode, ch_index; + + + /* + * Ad7616 has 16 channels divided in group A and group B. + * The range of channels from A are stored in registers with address 4 + * while channels from B are stored in register with address 6. + * The last bit from channels determines if it is from group A or B + * because the order of channels in iio is 0A, 0B, 1A, 1B... + */ + ch_index = ch >> 1; + + ch_addr = AD7616_RANGE_CH_ADDR(ch_index); + + if ((ch & 0x1) == 0) /* channel A */ + ch_addr += AD7616_RANGE_CH_A_ADDR_OFF; + else /* channel B */ + ch_addr += AD7616_RANGE_CH_B_ADDR_OFF; + + /* 0b01 for 2.5v, 0b10 for 5v and 0b11 for 10v */ + mode = AD7616_RANGE_CH_MODE(ch_index, ((val + 1) & 0b11)); + return st->bops->write_mask(st, ch_addr, AD7616_RANGE_CH_MSK(ch_index), + mode); +} + +static int ad7616_write_os_sw(struct iio_dev *indio_dev, int val) +{ + struct ad7606_state *st = iio_priv(indio_dev); + + return st->bops->write_mask(st, AD7616_CONFIGURATION_REGISTER, + AD7616_OS_MASK, val << 2); +} + +static int ad7606_write_scale_sw(struct iio_dev *indio_dev, int ch, int val) +{ + struct ad7606_state *st = iio_priv(indio_dev); + + return ad7606_spi_write_mask(st, + AD7606_RANGE_CH_ADDR(ch), + AD7606_RANGE_CH_MSK(ch), + AD7606_RANGE_CH_MODE(ch, val)); +} + +static int ad7606_write_os_sw(struct iio_dev *indio_dev, int val) +{ + struct ad7606_state *st = iio_priv(indio_dev); + + return ad7606_spi_reg_write(st, AD7606_OS_MODE, val); +} + +static int ad7616_sw_mode_config(struct iio_dev *indio_dev) +{ + struct ad7606_state *st = iio_priv(indio_dev); + + /* + * Scale can be configured individually for each channel + * in software mode. + */ + indio_dev->channels = ad7616_sw_channels; + + st->write_scale = ad7616_write_scale_sw; + st->write_os = &ad7616_write_os_sw; + + /* Activate Burst mode and SEQEN MODE */ + return st->bops->write_mask(st, + AD7616_CONFIGURATION_REGISTER, + AD7616_BURST_MODE | AD7616_SEQEN_MODE, + AD7616_BURST_MODE | AD7616_SEQEN_MODE); +} + +static int ad7606B_sw_mode_config(struct iio_dev *indio_dev) +{ + struct ad7606_state *st = iio_priv(indio_dev); + unsigned long os[3] = {1}; + + /* + * Software mode is enabled when all three oversampling + * pins are set to high. If oversampling gpios are defined + * in the device tree, then they need to be set to high, + * otherwise, they must be hardwired to VDD + */ + if (st->gpio_os) { + gpiod_set_array_value(ARRAY_SIZE(os), + st->gpio_os->desc, st->gpio_os->info, os); + } + /* OS of 128 and 256 are available only in software mode */ + st->oversampling_avail = ad7606B_oversampling_avail; + st->num_os_ratios = ARRAY_SIZE(ad7606B_oversampling_avail); + + st->write_scale = ad7606_write_scale_sw; + st->write_os = &ad7606_write_os_sw; + + /* Configure device spi to output on a single channel */ + st->bops->reg_write(st, + AD7606_CONFIGURATION_REGISTER, + AD7606_SINGLE_DOUT); + + /* + * Scale can be configured individually for each channel + * in software mode. + */ + indio_dev->channels = ad7606b_sw_channels; + + return 0; +} + +static const struct ad7606_bus_ops ad7606_spi_bops = { + .read_block = ad7606_spi_read_block, +}; + +static const struct ad7606_bus_ops ad7616_spi_bops = { + .read_block = ad7606_spi_read_block, + .reg_read = ad7606_spi_reg_read, + .reg_write = ad7606_spi_reg_write, + .write_mask = ad7606_spi_write_mask, + .rd_wr_cmd = ad7616_spi_rd_wr_cmd, + .sw_mode_config = ad7616_sw_mode_config, +}; + +static const struct ad7606_bus_ops ad7606B_spi_bops = { + .read_block = ad7606_spi_read_block, + .reg_read = ad7606_spi_reg_read, + .reg_write = ad7606_spi_reg_write, + .write_mask = ad7606_spi_write_mask, + .rd_wr_cmd = ad7606B_spi_rd_wr_cmd, + .sw_mode_config = ad7606B_sw_mode_config, +}; + +static int ad7606_spi_probe(struct spi_device *spi) +{ + const struct spi_device_id *id = spi_get_device_id(spi); + const struct ad7606_bus_ops *bops; + + switch (id->driver_data) { + case ID_AD7616: + bops = &ad7616_spi_bops; + break; + case ID_AD7606B: + bops = &ad7606B_spi_bops; + break; + default: + bops = &ad7606_spi_bops; + break; + } + + return ad7606_probe(&spi->dev, spi->irq, NULL, + id->name, id->driver_data, + bops); +} + +static const struct spi_device_id ad7606_id_table[] = { + { "ad7605-4", ID_AD7605_4 }, + { "ad7606-4", ID_AD7606_4 }, + { "ad7606-6", ID_AD7606_6 }, + { "ad7606-8", ID_AD7606_8 }, + { "ad7606b", ID_AD7606B }, + { "ad7616", ID_AD7616 }, + {} +}; +MODULE_DEVICE_TABLE(spi, ad7606_id_table); + +static const struct of_device_id ad7606_of_match[] = { + { .compatible = "adi,ad7605-4" }, + { .compatible = "adi,ad7606-4" }, + { .compatible = "adi,ad7606-6" }, + { .compatible = "adi,ad7606-8" }, + { .compatible = "adi,ad7606b" }, + { .compatible = "adi,ad7616" }, + { }, +}; +MODULE_DEVICE_TABLE(of, ad7606_of_match); + +static struct spi_driver ad7606_driver = { + .driver = { + .name = "ad7606", + .of_match_table = ad7606_of_match, + .pm = AD7606_PM_OPS, + }, + .probe = ad7606_spi_probe, + .id_table = ad7606_id_table, +}; +module_spi_driver(ad7606_driver); + +MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>"); +MODULE_DESCRIPTION("Analog Devices AD7606 ADC"); +MODULE_LICENSE("GPL v2"); |