diff options
Diffstat (limited to 'drivers/iio/addac/stx104.c')
| -rw-r--r-- | drivers/iio/addac/stx104.c | 466 |
1 files changed, 466 insertions, 0 deletions
diff --git a/drivers/iio/addac/stx104.c b/drivers/iio/addac/stx104.c new file mode 100644 index 0000000000..d1f7ce033b --- /dev/null +++ b/drivers/iio/addac/stx104.c @@ -0,0 +1,466 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * IIO driver for the Apex Embedded Systems STX104 + * Copyright (C) 2016 William Breathitt Gray + */ +#include <linux/bitfield.h> +#include <linux/bits.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/gpio/regmap.h> +#include <linux/iio/iio.h> +#include <linux/iio/types.h> +#include <linux/isa.h> +#include <linux/kernel.h> +#include <linux/limits.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/mutex.h> +#include <linux/regmap.h> +#include <linux/types.h> + +#define STX104_OUT_CHAN(chan) { \ + .type = IIO_VOLTAGE, \ + .channel = chan, \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .indexed = 1, \ + .output = 1 \ +} +#define STX104_IN_CHAN(chan, diff) { \ + .type = IIO_VOLTAGE, \ + .channel = chan, \ + .channel2 = chan, \ + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_HARDWAREGAIN) | \ + BIT(IIO_CHAN_INFO_OFFSET) | BIT(IIO_CHAN_INFO_SCALE), \ + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ + .indexed = 1, \ + .differential = diff \ +} + +#define STX104_NUM_OUT_CHAN 2 + +#define STX104_EXTENT 16 + +static unsigned int base[max_num_isa_dev(STX104_EXTENT)]; +static unsigned int num_stx104; +module_param_hw_array(base, uint, ioport, &num_stx104, 0); +MODULE_PARM_DESC(base, "Apex Embedded Systems STX104 base addresses"); + +#define STX104_AIO_BASE 0x0 +#define STX104_SOFTWARE_STROBE STX104_AIO_BASE +#define STX104_ADC_DATA STX104_AIO_BASE +#define STX104_ADC_CHANNEL (STX104_AIO_BASE + 0x2) +#define STX104_DIO_REG (STX104_AIO_BASE + 0x3) +#define STX104_DAC_BASE (STX104_AIO_BASE + 0x4) +#define STX104_ADC_STATUS (STX104_AIO_BASE + 0x8) +#define STX104_ADC_CONTROL (STX104_AIO_BASE + 0x9) +#define STX104_ADC_CONFIGURATION (STX104_AIO_BASE + 0x11) + +#define STX104_AIO_DATA_STRIDE 2 +#define STX104_DAC_OFFSET(_channel) (STX104_DAC_BASE + STX104_AIO_DATA_STRIDE * (_channel)) + +/* ADC Channel */ +#define STX104_FC GENMASK(3, 0) +#define STX104_LC GENMASK(7, 4) +#define STX104_SINGLE_CHANNEL(_channel) \ + (u8_encode_bits(_channel, STX104_FC) | u8_encode_bits(_channel, STX104_LC)) + +/* ADC Status */ +#define STX104_SD BIT(5) +#define STX104_CNV BIT(7) +#define STX104_DIFFERENTIAL 1 + +/* ADC Control */ +#define STX104_ALSS GENMASK(1, 0) +#define STX104_SOFTWARE_TRIGGER u8_encode_bits(0x0, STX104_ALSS) + +/* ADC Configuration */ +#define STX104_GAIN GENMASK(1, 0) +#define STX104_ADBU BIT(2) +#define STX104_BIPOLAR 0 +#define STX104_GAIN_X1 0 +#define STX104_GAIN_X2 1 +#define STX104_GAIN_X4 2 +#define STX104_GAIN_X8 3 + +/** + * struct stx104_iio - IIO device private data structure + * @lock: synchronization lock to prevent I/O race conditions + * @aio_data_map: Regmap for analog I/O data + * @aio_ctl_map: Regmap for analog I/O control + */ +struct stx104_iio { + struct mutex lock; + struct regmap *aio_data_map; + struct regmap *aio_ctl_map; +}; + +static const struct regmap_range aio_ctl_wr_ranges[] = { + regmap_reg_range(0x0, 0x0), regmap_reg_range(0x2, 0x2), regmap_reg_range(0x9, 0x9), + regmap_reg_range(0x11, 0x11), +}; +static const struct regmap_range aio_ctl_rd_ranges[] = { + regmap_reg_range(0x2, 0x2), regmap_reg_range(0x8, 0x9), regmap_reg_range(0x11, 0x11), +}; +static const struct regmap_range aio_ctl_volatile_ranges[] = { + regmap_reg_range(0x8, 0x8), +}; +static const struct regmap_access_table aio_ctl_wr_table = { + .yes_ranges = aio_ctl_wr_ranges, + .n_yes_ranges = ARRAY_SIZE(aio_ctl_wr_ranges), +}; +static const struct regmap_access_table aio_ctl_rd_table = { + .yes_ranges = aio_ctl_rd_ranges, + .n_yes_ranges = ARRAY_SIZE(aio_ctl_rd_ranges), +}; +static const struct regmap_access_table aio_ctl_volatile_table = { + .yes_ranges = aio_ctl_volatile_ranges, + .n_yes_ranges = ARRAY_SIZE(aio_ctl_volatile_ranges), +}; + +static const struct regmap_config aio_ctl_regmap_config = { + .name = "aio_ctl", + .reg_bits = 8, + .reg_stride = 1, + .reg_base = STX104_AIO_BASE, + .val_bits = 8, + .io_port = true, + .wr_table = &aio_ctl_wr_table, + .rd_table = &aio_ctl_rd_table, + .volatile_table = &aio_ctl_volatile_table, + .cache_type = REGCACHE_FLAT, +}; + +static const struct regmap_range aio_data_wr_ranges[] = { + regmap_reg_range(0x4, 0x6), +}; +static const struct regmap_range aio_data_rd_ranges[] = { + regmap_reg_range(0x0, 0x0), +}; +static const struct regmap_access_table aio_data_wr_table = { + .yes_ranges = aio_data_wr_ranges, + .n_yes_ranges = ARRAY_SIZE(aio_data_wr_ranges), +}; +static const struct regmap_access_table aio_data_rd_table = { + .yes_ranges = aio_data_rd_ranges, + .n_yes_ranges = ARRAY_SIZE(aio_data_rd_ranges), +}; + +static const struct regmap_config aio_data_regmap_config = { + .name = "aio_data", + .reg_bits = 16, + .reg_stride = STX104_AIO_DATA_STRIDE, + .reg_base = STX104_AIO_BASE, + .val_bits = 16, + .io_port = true, + .wr_table = &aio_data_wr_table, + .rd_table = &aio_data_rd_table, + .volatile_table = &aio_data_rd_table, + .cache_type = REGCACHE_FLAT, +}; + +static const struct regmap_config dio_regmap_config = { + .name = "dio", + .reg_bits = 8, + .reg_stride = 1, + .reg_base = STX104_DIO_REG, + .val_bits = 8, + .io_port = true, +}; + +static int stx104_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int *val, int *val2, long mask) +{ + struct stx104_iio *const priv = iio_priv(indio_dev); + int err; + unsigned int adc_config; + unsigned int value; + unsigned int adc_status; + + switch (mask) { + case IIO_CHAN_INFO_HARDWAREGAIN: + err = regmap_read(priv->aio_ctl_map, STX104_ADC_CONFIGURATION, &adc_config); + if (err) + return err; + + *val = BIT(u8_get_bits(adc_config, STX104_GAIN)); + return IIO_VAL_INT; + case IIO_CHAN_INFO_RAW: + if (chan->output) { + err = regmap_read(priv->aio_data_map, STX104_DAC_OFFSET(chan->channel), + &value); + if (err) + return err; + *val = value; + return IIO_VAL_INT; + } + + mutex_lock(&priv->lock); + + /* select ADC channel */ + err = regmap_write(priv->aio_ctl_map, STX104_ADC_CHANNEL, + STX104_SINGLE_CHANNEL(chan->channel)); + if (err) { + mutex_unlock(&priv->lock); + return err; + } + + /* + * Trigger ADC sample capture by writing to the 8-bit Software Strobe Register and + * wait for completion; the conversion time range is 5 microseconds to 53.68 seconds + * in steps of 25 nanoseconds. The actual Analog Input Frame Timer time interval is + * calculated as: + * ai_time_frame_ns = ( AIFT + 1 ) * ( 25 nanoseconds ). + * Where 0 <= AIFT <= 2147483648. + */ + err = regmap_write(priv->aio_ctl_map, STX104_SOFTWARE_STROBE, 0); + if (err) { + mutex_unlock(&priv->lock); + return err; + } + err = regmap_read_poll_timeout(priv->aio_ctl_map, STX104_ADC_STATUS, adc_status, + !u8_get_bits(adc_status, STX104_CNV), 0, 53687092); + if (err) { + mutex_unlock(&priv->lock); + return err; + } + + err = regmap_read(priv->aio_data_map, STX104_ADC_DATA, &value); + if (err) { + mutex_unlock(&priv->lock); + return err; + } + *val = value; + + mutex_unlock(&priv->lock); + return IIO_VAL_INT; + case IIO_CHAN_INFO_OFFSET: + /* get ADC bipolar/unipolar configuration */ + err = regmap_read(priv->aio_ctl_map, STX104_ADC_CONFIGURATION, &adc_config); + if (err) + return err; + + *val = (u8_get_bits(adc_config, STX104_ADBU) == STX104_BIPOLAR) ? -32768 : 0; + return IIO_VAL_INT; + case IIO_CHAN_INFO_SCALE: + /* get ADC bipolar/unipolar and gain configuration */ + err = regmap_read(priv->aio_ctl_map, STX104_ADC_CONFIGURATION, &adc_config); + if (err) + return err; + + *val = 5; + *val2 = (u8_get_bits(adc_config, STX104_ADBU) == STX104_BIPOLAR) ? 14 : 15; + *val2 += u8_get_bits(adc_config, STX104_GAIN); + return IIO_VAL_FRACTIONAL_LOG2; + } + + return -EINVAL; +} + +static int stx104_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, int val, int val2, long mask) +{ + struct stx104_iio *const priv = iio_priv(indio_dev); + u8 gain; + + switch (mask) { + case IIO_CHAN_INFO_HARDWAREGAIN: + /* Only four gain states (x1, x2, x4, x8) */ + switch (val) { + case 1: + gain = STX104_GAIN_X1; + break; + case 2: + gain = STX104_GAIN_X2; + break; + case 4: + gain = STX104_GAIN_X4; + break; + case 8: + gain = STX104_GAIN_X8; + break; + default: + return -EINVAL; + } + + return regmap_write(priv->aio_ctl_map, STX104_ADC_CONFIGURATION, gain); + case IIO_CHAN_INFO_RAW: + if (!chan->output) + return -EINVAL; + + if (val < 0 || val > U16_MAX) + return -EINVAL; + + return regmap_write(priv->aio_data_map, STX104_DAC_OFFSET(chan->channel), val); + } + + return -EINVAL; +} + +static const struct iio_info stx104_info = { + .read_raw = stx104_read_raw, + .write_raw = stx104_write_raw +}; + +/* single-ended input channels configuration */ +static const struct iio_chan_spec stx104_channels_sing[] = { + STX104_OUT_CHAN(0), STX104_OUT_CHAN(1), + STX104_IN_CHAN(0, 0), STX104_IN_CHAN(1, 0), STX104_IN_CHAN(2, 0), + STX104_IN_CHAN(3, 0), STX104_IN_CHAN(4, 0), STX104_IN_CHAN(5, 0), + STX104_IN_CHAN(6, 0), STX104_IN_CHAN(7, 0), STX104_IN_CHAN(8, 0), + STX104_IN_CHAN(9, 0), STX104_IN_CHAN(10, 0), STX104_IN_CHAN(11, 0), + STX104_IN_CHAN(12, 0), STX104_IN_CHAN(13, 0), STX104_IN_CHAN(14, 0), + STX104_IN_CHAN(15, 0) +}; +/* differential input channels configuration */ +static const struct iio_chan_spec stx104_channels_diff[] = { + STX104_OUT_CHAN(0), STX104_OUT_CHAN(1), + STX104_IN_CHAN(0, 1), STX104_IN_CHAN(1, 1), STX104_IN_CHAN(2, 1), + STX104_IN_CHAN(3, 1), STX104_IN_CHAN(4, 1), STX104_IN_CHAN(5, 1), + STX104_IN_CHAN(6, 1), STX104_IN_CHAN(7, 1) +}; + +static int stx104_reg_mask_xlate(struct gpio_regmap *const gpio, const unsigned int base, + unsigned int offset, unsigned int *const reg, + unsigned int *const mask) +{ + /* Output lines are located at same register bit offsets as input lines */ + if (offset >= 4) + offset -= 4; + + *reg = base; + *mask = BIT(offset); + + return 0; +} + +#define STX104_NGPIO 8 +static const char *stx104_names[STX104_NGPIO] = { + "DIN0", "DIN1", "DIN2", "DIN3", "DOUT0", "DOUT1", "DOUT2", "DOUT3" +}; + +static int stx104_init_hw(struct stx104_iio *const priv) +{ + int err; + + /* configure device for software trigger operation */ + err = regmap_write(priv->aio_ctl_map, STX104_ADC_CONTROL, STX104_SOFTWARE_TRIGGER); + if (err) + return err; + + /* initialize gain setting to x1 */ + err = regmap_write(priv->aio_ctl_map, STX104_ADC_CONFIGURATION, STX104_GAIN_X1); + if (err) + return err; + + /* initialize DAC outputs to 0V */ + err = regmap_write(priv->aio_data_map, STX104_DAC_BASE, 0); + if (err) + return err; + err = regmap_write(priv->aio_data_map, STX104_DAC_BASE + STX104_AIO_DATA_STRIDE, 0); + if (err) + return err; + + return 0; +} + +static int stx104_probe(struct device *dev, unsigned int id) +{ + struct iio_dev *indio_dev; + struct stx104_iio *priv; + struct gpio_regmap_config gpio_config; + void __iomem *stx104_base; + struct regmap *aio_ctl_map; + struct regmap *aio_data_map; + struct regmap *dio_map; + int err; + unsigned int adc_status; + + indio_dev = devm_iio_device_alloc(dev, sizeof(*priv)); + if (!indio_dev) + return -ENOMEM; + + if (!devm_request_region(dev, base[id], STX104_EXTENT, + dev_name(dev))) { + dev_err(dev, "Unable to lock port addresses (0x%X-0x%X)\n", + base[id], base[id] + STX104_EXTENT); + return -EBUSY; + } + + stx104_base = devm_ioport_map(dev, base[id], STX104_EXTENT); + if (!stx104_base) + return -ENOMEM; + + aio_ctl_map = devm_regmap_init_mmio(dev, stx104_base, &aio_ctl_regmap_config); + if (IS_ERR(aio_ctl_map)) + return dev_err_probe(dev, PTR_ERR(aio_ctl_map), + "Unable to initialize aio_ctl register map\n"); + + aio_data_map = devm_regmap_init_mmio(dev, stx104_base, &aio_data_regmap_config); + if (IS_ERR(aio_data_map)) + return dev_err_probe(dev, PTR_ERR(aio_data_map), + "Unable to initialize aio_data register map\n"); + + dio_map = devm_regmap_init_mmio(dev, stx104_base, &dio_regmap_config); + if (IS_ERR(dio_map)) + return dev_err_probe(dev, PTR_ERR(dio_map), + "Unable to initialize dio register map\n"); + + priv = iio_priv(indio_dev); + priv->aio_ctl_map = aio_ctl_map; + priv->aio_data_map = aio_data_map; + + indio_dev->info = &stx104_info; + indio_dev->modes = INDIO_DIRECT_MODE; + + err = regmap_read(aio_ctl_map, STX104_ADC_STATUS, &adc_status); + if (err) + return err; + + if (u8_get_bits(adc_status, STX104_SD) == STX104_DIFFERENTIAL) { + indio_dev->num_channels = ARRAY_SIZE(stx104_channels_diff); + indio_dev->channels = stx104_channels_diff; + } else { + indio_dev->num_channels = ARRAY_SIZE(stx104_channels_sing); + indio_dev->channels = stx104_channels_sing; + } + + indio_dev->name = dev_name(dev); + + mutex_init(&priv->lock); + + err = stx104_init_hw(priv); + if (err) + return err; + + err = devm_iio_device_register(dev, indio_dev); + if (err) + return err; + + gpio_config = (struct gpio_regmap_config) { + .parent = dev, + .regmap = dio_map, + .ngpio = STX104_NGPIO, + .names = stx104_names, + .reg_dat_base = GPIO_REGMAP_ADDR(STX104_DIO_REG), + .reg_set_base = GPIO_REGMAP_ADDR(STX104_DIO_REG), + .ngpio_per_reg = STX104_NGPIO, + .reg_mask_xlate = stx104_reg_mask_xlate, + .drvdata = dio_map, + }; + + return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &gpio_config)); +} + +static struct isa_driver stx104_driver = { + .probe = stx104_probe, + .driver = { + .name = "stx104" + }, +}; + +module_isa_driver(stx104_driver, num_stx104); + +MODULE_AUTHOR("William Breathitt Gray <vilhelm.gray@gmail.com>"); +MODULE_DESCRIPTION("Apex Embedded Systems STX104 IIO driver"); +MODULE_LICENSE("GPL v2"); |