diff options
Diffstat (limited to 'drivers/iio/dac/ad5755.c')
| -rw-r--r-- | drivers/iio/dac/ad5755.c | 650 |
1 files changed, 650 insertions, 0 deletions
diff --git a/drivers/iio/dac/ad5755.c b/drivers/iio/dac/ad5755.c new file mode 100644 index 0000000..e6dbe5f --- /dev/null +++ b/drivers/iio/dac/ad5755.c @@ -0,0 +1,650 @@ +/* + * AD5755, AD5755-1, AD5757, AD5735, AD5737 Digital to analog converters driver + * + * Copyright 2012 Analog Devices Inc. + * + * Licensed under the GPL-2. + */ + +#include <linux/device.h> +#include <linux/err.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/spi/spi.h> +#include <linux/slab.h> +#include <linux/sysfs.h> +#include <linux/delay.h> +#include <linux/iio/iio.h> +#include <linux/iio/sysfs.h> +#include <linux/platform_data/ad5755.h> + +#define AD5755_NUM_CHANNELS 4 + +#define AD5755_ADDR(x) ((x) << 16) + +#define AD5755_WRITE_REG_DATA(chan) (chan) +#define AD5755_WRITE_REG_GAIN(chan) (0x08 | (chan)) +#define AD5755_WRITE_REG_OFFSET(chan) (0x10 | (chan)) +#define AD5755_WRITE_REG_CTRL(chan) (0x1c | (chan)) + +#define AD5755_READ_REG_DATA(chan) (chan) +#define AD5755_READ_REG_CTRL(chan) (0x4 | (chan)) +#define AD5755_READ_REG_GAIN(chan) (0x8 | (chan)) +#define AD5755_READ_REG_OFFSET(chan) (0xc | (chan)) +#define AD5755_READ_REG_CLEAR(chan) (0x10 | (chan)) +#define AD5755_READ_REG_SLEW(chan) (0x14 | (chan)) +#define AD5755_READ_REG_STATUS 0x18 +#define AD5755_READ_REG_MAIN 0x19 +#define AD5755_READ_REG_DC_DC 0x1a + +#define AD5755_CTRL_REG_SLEW 0x0 +#define AD5755_CTRL_REG_MAIN 0x1 +#define AD5755_CTRL_REG_DAC 0x2 +#define AD5755_CTRL_REG_DC_DC 0x3 +#define AD5755_CTRL_REG_SW 0x4 + +#define AD5755_READ_FLAG 0x800000 + +#define AD5755_NOOP 0x1CE000 + +#define AD5755_DAC_INT_EN BIT(8) +#define AD5755_DAC_CLR_EN BIT(7) +#define AD5755_DAC_OUT_EN BIT(6) +#define AD5755_DAC_INT_CURRENT_SENSE_RESISTOR BIT(5) +#define AD5755_DAC_DC_DC_EN BIT(4) +#define AD5755_DAC_VOLTAGE_OVERRANGE_EN BIT(3) + +#define AD5755_DC_DC_MAXV 0 +#define AD5755_DC_DC_FREQ_SHIFT 2 +#define AD5755_DC_DC_PHASE_SHIFT 4 +#define AD5755_EXT_DC_DC_COMP_RES BIT(6) + +#define AD5755_SLEW_STEP_SIZE_SHIFT 0 +#define AD5755_SLEW_RATE_SHIFT 3 +#define AD5755_SLEW_ENABLE BIT(12) + +/** + * struct ad5755_chip_info - chip specific information + * @channel_template: channel specification + * @calib_shift: shift for the calibration data registers + * @has_voltage_out: whether the chip has voltage outputs + */ +struct ad5755_chip_info { + const struct iio_chan_spec channel_template; + unsigned int calib_shift; + bool has_voltage_out; +}; + +/** + * struct ad5755_state - driver instance specific data + * @spi: spi device the driver is attached to + * @chip_info: chip model specific constants, available modes etc + * @pwr_down: bitmask which contains hether a channel is powered down or not + * @ctrl: software shadow of the channel ctrl registers + * @channels: iio channel spec for the device + * @data: spi transfer buffers + */ +struct ad5755_state { + struct spi_device *spi; + const struct ad5755_chip_info *chip_info; + unsigned int pwr_down; + unsigned int ctrl[AD5755_NUM_CHANNELS]; + struct iio_chan_spec channels[AD5755_NUM_CHANNELS]; + + /* + * DMA (thus cache coherency maintenance) requires the + * transfer buffers to live in their own cache lines. + */ + + union { + u32 d32; + u8 d8[4]; + } data[2] ____cacheline_aligned; +}; + +enum ad5755_type { + ID_AD5755, + ID_AD5757, + ID_AD5735, + ID_AD5737, +}; + +static int ad5755_write_unlocked(struct iio_dev *indio_dev, + unsigned int reg, unsigned int val) +{ + struct ad5755_state *st = iio_priv(indio_dev); + + st->data[0].d32 = cpu_to_be32((reg << 16) | val); + + return spi_write(st->spi, &st->data[0].d8[1], 3); +} + +static int ad5755_write_ctrl_unlocked(struct iio_dev *indio_dev, + unsigned int channel, unsigned int reg, unsigned int val) +{ + return ad5755_write_unlocked(indio_dev, + AD5755_WRITE_REG_CTRL(channel), (reg << 13) | val); +} + +static int ad5755_write(struct iio_dev *indio_dev, unsigned int reg, + unsigned int val) +{ + int ret; + + mutex_lock(&indio_dev->mlock); + ret = ad5755_write_unlocked(indio_dev, reg, val); + mutex_unlock(&indio_dev->mlock); + + return ret; +} + +static int ad5755_write_ctrl(struct iio_dev *indio_dev, unsigned int channel, + unsigned int reg, unsigned int val) +{ + int ret; + + mutex_lock(&indio_dev->mlock); + ret = ad5755_write_ctrl_unlocked(indio_dev, channel, reg, val); + mutex_unlock(&indio_dev->mlock); + + return ret; +} + +static int ad5755_read(struct iio_dev *indio_dev, unsigned int addr) +{ + struct ad5755_state *st = iio_priv(indio_dev); + struct spi_message m; + int ret; + struct spi_transfer t[] = { + { + .tx_buf = &st->data[0].d8[1], + .len = 3, + .cs_change = 1, + }, { + .tx_buf = &st->data[1].d8[1], + .rx_buf = &st->data[1].d8[1], + .len = 3, + }, + }; + + spi_message_init(&m); + spi_message_add_tail(&t[0], &m); + spi_message_add_tail(&t[1], &m); + + mutex_lock(&indio_dev->mlock); + + st->data[0].d32 = cpu_to_be32(AD5755_READ_FLAG | (addr << 16)); + st->data[1].d32 = cpu_to_be32(AD5755_NOOP); + + ret = spi_sync(st->spi, &m); + if (ret >= 0) + ret = be32_to_cpu(st->data[1].d32) & 0xffff; + + mutex_unlock(&indio_dev->mlock); + + return ret; +} + +static int ad5755_update_dac_ctrl(struct iio_dev *indio_dev, + unsigned int channel, unsigned int set, unsigned int clr) +{ + struct ad5755_state *st = iio_priv(indio_dev); + int ret; + + st->ctrl[channel] |= set; + st->ctrl[channel] &= ~clr; + + ret = ad5755_write_ctrl_unlocked(indio_dev, channel, + AD5755_CTRL_REG_DAC, st->ctrl[channel]); + + return ret; +} + +static int ad5755_set_channel_pwr_down(struct iio_dev *indio_dev, + unsigned int channel, bool pwr_down) +{ + struct ad5755_state *st = iio_priv(indio_dev); + unsigned int mask = BIT(channel); + + mutex_lock(&indio_dev->mlock); + + if ((bool)(st->pwr_down & mask) == pwr_down) + goto out_unlock; + + if (!pwr_down) { + st->pwr_down &= ~mask; + ad5755_update_dac_ctrl(indio_dev, channel, + AD5755_DAC_INT_EN | AD5755_DAC_DC_DC_EN, 0); + udelay(200); + ad5755_update_dac_ctrl(indio_dev, channel, + AD5755_DAC_OUT_EN, 0); + } else { + st->pwr_down |= mask; + ad5755_update_dac_ctrl(indio_dev, channel, + 0, AD5755_DAC_INT_EN | AD5755_DAC_OUT_EN | + AD5755_DAC_DC_DC_EN); + } + +out_unlock: + mutex_unlock(&indio_dev->mlock); + + return 0; +} + +static const int ad5755_min_max_table[][2] = { + [AD5755_MODE_VOLTAGE_0V_5V] = { 0, 5000 }, + [AD5755_MODE_VOLTAGE_0V_10V] = { 0, 10000 }, + [AD5755_MODE_VOLTAGE_PLUSMINUS_5V] = { -5000, 5000 }, + [AD5755_MODE_VOLTAGE_PLUSMINUS_10V] = { -10000, 10000 }, + [AD5755_MODE_CURRENT_4mA_20mA] = { 4, 20 }, + [AD5755_MODE_CURRENT_0mA_20mA] = { 0, 20 }, + [AD5755_MODE_CURRENT_0mA_24mA] = { 0, 24 }, +}; + +static void ad5755_get_min_max(struct ad5755_state *st, + struct iio_chan_spec const *chan, int *min, int *max) +{ + enum ad5755_mode mode = st->ctrl[chan->channel] & 7; + *min = ad5755_min_max_table[mode][0]; + *max = ad5755_min_max_table[mode][1]; +} + +static inline int ad5755_get_offset(struct ad5755_state *st, + struct iio_chan_spec const *chan) +{ + int min, max; + + ad5755_get_min_max(st, chan, &min, &max); + return (min * (1 << chan->scan_type.realbits)) / (max - min); +} + +static inline int ad5755_get_scale(struct ad5755_state *st, + struct iio_chan_spec const *chan) +{ + int min, max; + + ad5755_get_min_max(st, chan, &min, &max); + return ((max - min) * 1000000000ULL) >> chan->scan_type.realbits; +} + +static int ad5755_chan_reg_info(struct ad5755_state *st, + struct iio_chan_spec const *chan, long info, bool write, + unsigned int *reg, unsigned int *shift, unsigned int *offset) +{ + switch (info) { + case IIO_CHAN_INFO_RAW: + if (write) + *reg = AD5755_WRITE_REG_DATA(chan->address); + else + *reg = AD5755_READ_REG_DATA(chan->address); + *shift = chan->scan_type.shift; + *offset = 0; + break; + case IIO_CHAN_INFO_CALIBBIAS: + if (write) + *reg = AD5755_WRITE_REG_OFFSET(chan->address); + else + *reg = AD5755_READ_REG_OFFSET(chan->address); + *shift = st->chip_info->calib_shift; + *offset = 32768; + break; + case IIO_CHAN_INFO_CALIBSCALE: + if (write) + *reg = AD5755_WRITE_REG_GAIN(chan->address); + else + *reg = AD5755_READ_REG_GAIN(chan->address); + *shift = st->chip_info->calib_shift; + *offset = 0; + break; + default: + return -EINVAL; + } + + return 0; +} + +static int ad5755_read_raw(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, int *val, int *val2, long info) +{ + struct ad5755_state *st = iio_priv(indio_dev); + unsigned int reg, shift, offset; + int ret; + + switch (info) { + case IIO_CHAN_INFO_SCALE: + *val = 0; + *val2 = ad5755_get_scale(st, chan); + return IIO_VAL_INT_PLUS_NANO; + case IIO_CHAN_INFO_OFFSET: + *val = ad5755_get_offset(st, chan); + return IIO_VAL_INT; + default: + ret = ad5755_chan_reg_info(st, chan, info, false, + ®, &shift, &offset); + if (ret) + return ret; + + ret = ad5755_read(indio_dev, reg); + if (ret < 0) + return ret; + + *val = (ret - offset) >> shift; + + return IIO_VAL_INT; + } + + return -EINVAL; +} + +static int ad5755_write_raw(struct iio_dev *indio_dev, + const struct iio_chan_spec *chan, int val, int val2, long info) +{ + struct ad5755_state *st = iio_priv(indio_dev); + unsigned int shift, reg, offset; + int ret; + + ret = ad5755_chan_reg_info(st, chan, info, true, + ®, &shift, &offset); + if (ret) + return ret; + + val <<= shift; + val += offset; + + if (val < 0 || val > 0xffff) + return -EINVAL; + + return ad5755_write(indio_dev, reg, val); +} + +static ssize_t ad5755_read_powerdown(struct iio_dev *indio_dev, uintptr_t priv, + const struct iio_chan_spec *chan, char *buf) +{ + struct ad5755_state *st = iio_priv(indio_dev); + + return sprintf(buf, "%d\n", + (bool)(st->pwr_down & (1 << chan->channel))); +} + +static ssize_t ad5755_write_powerdown(struct iio_dev *indio_dev, uintptr_t priv, + struct iio_chan_spec const *chan, const char *buf, size_t len) +{ + bool pwr_down; + int ret; + + ret = strtobool(buf, &pwr_down); + if (ret) + return ret; + + ret = ad5755_set_channel_pwr_down(indio_dev, chan->channel, pwr_down); + return ret ? ret : len; +} + +static const struct iio_info ad5755_info = { + .read_raw = ad5755_read_raw, + .write_raw = ad5755_write_raw, + .driver_module = THIS_MODULE, +}; + +static const struct iio_chan_spec_ext_info ad5755_ext_info[] = { + { + .name = "powerdown", + .read = ad5755_read_powerdown, + .write = ad5755_write_powerdown, + }, + { }, +}; + +#define AD5755_CHANNEL(_bits) { \ + .indexed = 1, \ + .output = 1, \ + .info_mask = IIO_CHAN_INFO_RAW_SEPARATE_BIT | \ + IIO_CHAN_INFO_SCALE_SEPARATE_BIT | \ + IIO_CHAN_INFO_OFFSET_SEPARATE_BIT | \ + IIO_CHAN_INFO_CALIBSCALE_SEPARATE_BIT | \ + IIO_CHAN_INFO_CALIBBIAS_SEPARATE_BIT, \ + .scan_type = IIO_ST('u', (_bits), 16, 16 - (_bits)), \ + .ext_info = ad5755_ext_info, \ +} + +static const struct ad5755_chip_info ad5755_chip_info_tbl[] = { + [ID_AD5735] = { + .channel_template = AD5755_CHANNEL(14), + .has_voltage_out = true, + .calib_shift = 4, + }, + [ID_AD5737] = { + .channel_template = AD5755_CHANNEL(14), + .has_voltage_out = false, + .calib_shift = 4, + }, + [ID_AD5755] = { + .channel_template = AD5755_CHANNEL(16), + .has_voltage_out = true, + .calib_shift = 0, + }, + [ID_AD5757] = { + .channel_template = AD5755_CHANNEL(16), + .has_voltage_out = false, + .calib_shift = 0, + }, +}; + +static bool ad5755_is_valid_mode(struct ad5755_state *st, enum ad5755_mode mode) +{ + switch (mode) { + case AD5755_MODE_VOLTAGE_0V_5V: + case AD5755_MODE_VOLTAGE_0V_10V: + case AD5755_MODE_VOLTAGE_PLUSMINUS_5V: + case AD5755_MODE_VOLTAGE_PLUSMINUS_10V: + return st->chip_info->has_voltage_out; + case AD5755_MODE_CURRENT_4mA_20mA: + case AD5755_MODE_CURRENT_0mA_20mA: + case AD5755_MODE_CURRENT_0mA_24mA: + return true; + default: + return false; + } +} + +static int __devinit ad5755_setup_pdata(struct iio_dev *indio_dev, + const struct ad5755_platform_data *pdata) +{ + struct ad5755_state *st = iio_priv(indio_dev); + unsigned int ret; + unsigned int val; + unsigned int i; + + if (pdata->dc_dc_phase > AD5755_DC_DC_PHASE_90_DEGREE || + pdata->dc_dc_freq > AD5755_DC_DC_FREQ_650kHZ || + pdata->dc_dc_maxv > AD5755_DC_DC_MAXV_29V5) + return -EINVAL; + + val = pdata->dc_dc_maxv << AD5755_DC_DC_MAXV; + val |= pdata->dc_dc_freq << AD5755_DC_DC_FREQ_SHIFT; + val |= pdata->dc_dc_phase << AD5755_DC_DC_PHASE_SHIFT; + if (pdata->ext_dc_dc_compenstation_resistor) + val |= AD5755_EXT_DC_DC_COMP_RES; + + ret = ad5755_write_ctrl(indio_dev, 0, AD5755_CTRL_REG_DC_DC, val); + if (ret < 0) + return ret; + + for (i = 0; i < ARRAY_SIZE(pdata->dac); ++i) { + val = pdata->dac[i].slew.step_size << + AD5755_SLEW_STEP_SIZE_SHIFT; + val |= pdata->dac[i].slew.rate << + AD5755_SLEW_RATE_SHIFT; + if (pdata->dac[i].slew.enable) + val |= AD5755_SLEW_ENABLE; + + ret = ad5755_write_ctrl(indio_dev, i, + AD5755_CTRL_REG_SLEW, val); + if (ret < 0) + return ret; + } + + for (i = 0; i < ARRAY_SIZE(pdata->dac); ++i) { + if (!ad5755_is_valid_mode(st, pdata->dac[i].mode)) + return -EINVAL; + + val = 0; + if (!pdata->dac[i].ext_current_sense_resistor) + val |= AD5755_DAC_INT_CURRENT_SENSE_RESISTOR; + if (pdata->dac[i].enable_voltage_overrange) + val |= AD5755_DAC_VOLTAGE_OVERRANGE_EN; + val |= pdata->dac[i].mode; + + ret = ad5755_update_dac_ctrl(indio_dev, i, val, 0); + if (ret < 0) + return ret; + } + + return 0; +} + +static bool __devinit ad5755_is_voltage_mode(enum ad5755_mode mode) +{ + switch (mode) { + case AD5755_MODE_VOLTAGE_0V_5V: + case AD5755_MODE_VOLTAGE_0V_10V: + case AD5755_MODE_VOLTAGE_PLUSMINUS_5V: + case AD5755_MODE_VOLTAGE_PLUSMINUS_10V: + return true; + default: + return false; + } +} + +static int __devinit ad5755_init_channels(struct iio_dev *indio_dev, + const struct ad5755_platform_data *pdata) +{ + struct ad5755_state *st = iio_priv(indio_dev); + struct iio_chan_spec *channels = st->channels; + unsigned int i; + + for (i = 0; i < AD5755_NUM_CHANNELS; ++i) { + channels[i] = st->chip_info->channel_template; + channels[i].channel = i; + channels[i].address = i; + if (pdata && ad5755_is_voltage_mode(pdata->dac[i].mode)) + channels[i].type = IIO_VOLTAGE; + else + channels[i].type = IIO_CURRENT; + } + + indio_dev->channels = channels; + + return 0; +} + +#define AD5755_DEFAULT_DAC_PDATA { \ + .mode = AD5755_MODE_CURRENT_4mA_20mA, \ + .ext_current_sense_resistor = true, \ + .enable_voltage_overrange = false, \ + .slew = { \ + .enable = false, \ + .rate = AD5755_SLEW_RATE_64k, \ + .step_size = AD5755_SLEW_STEP_SIZE_1, \ + }, \ + } + +static const struct ad5755_platform_data ad5755_default_pdata = { + .ext_dc_dc_compenstation_resistor = false, + .dc_dc_phase = AD5755_DC_DC_PHASE_ALL_SAME_EDGE, + .dc_dc_freq = AD5755_DC_DC_FREQ_410kHZ, + .dc_dc_maxv = AD5755_DC_DC_MAXV_23V, + .dac = { + [0] = AD5755_DEFAULT_DAC_PDATA, + [1] = AD5755_DEFAULT_DAC_PDATA, + [2] = AD5755_DEFAULT_DAC_PDATA, + [3] = AD5755_DEFAULT_DAC_PDATA, + }, +}; + +static int __devinit ad5755_probe(struct spi_device *spi) +{ + enum ad5755_type type = spi_get_device_id(spi)->driver_data; + const struct ad5755_platform_data *pdata = dev_get_platdata(&spi->dev); + struct iio_dev *indio_dev; + struct ad5755_state *st; + int ret; + + indio_dev = iio_device_alloc(sizeof(*st)); + if (indio_dev == NULL) { + dev_err(&spi->dev, "Failed to allocate iio device\n"); + return -ENOMEM; + } + + st = iio_priv(indio_dev); + spi_set_drvdata(spi, indio_dev); + + st->chip_info = &ad5755_chip_info_tbl[type]; + st->spi = spi; + st->pwr_down = 0xf; + + indio_dev->dev.parent = &spi->dev; + indio_dev->name = spi_get_device_id(spi)->name; + indio_dev->info = &ad5755_info; + indio_dev->modes = INDIO_DIRECT_MODE; + indio_dev->num_channels = AD5755_NUM_CHANNELS; + + if (!pdata) + pdata = &ad5755_default_pdata; + + ret = ad5755_init_channels(indio_dev, pdata); + if (ret) + goto error_free; + + ret = ad5755_setup_pdata(indio_dev, pdata); + if (ret) + goto error_free; + + ret = iio_device_register(indio_dev); + if (ret) { + dev_err(&spi->dev, "Failed to register iio device: %d\n", ret); + goto error_free; + } + + return 0; + +error_free: + iio_device_free(indio_dev); + + return ret; +} + +static int __devexit ad5755_remove(struct spi_device *spi) +{ + struct iio_dev *indio_dev = spi_get_drvdata(spi); + + iio_device_unregister(indio_dev); + iio_device_free(indio_dev); + + return 0; +} + +static const struct spi_device_id ad5755_id[] = { + { "ad5755", ID_AD5755 }, + { "ad5755-1", ID_AD5755 }, + { "ad5757", ID_AD5757 }, + { "ad5735", ID_AD5735 }, + { "ad5737", ID_AD5737 }, + {} +}; +MODULE_DEVICE_TABLE(spi, ad5755_id); + +static struct spi_driver ad5755_driver = { + .driver = { + .name = "ad5755", + .owner = THIS_MODULE, + }, + .probe = ad5755_probe, + .remove = __devexit_p(ad5755_remove), + .id_table = ad5755_id, +}; +module_spi_driver(ad5755_driver); + +MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); +MODULE_DESCRIPTION("Analog Devices AD5755/55-1/57/35/37 DAC"); +MODULE_LICENSE("GPL v2"); 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