--- /dev/null
+/*
+ * AD5791, AD5791 Voltage Output Digital to Analog Converter
+ *
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/gpio.h>
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/regulator/consumer.h>
+
+#include "../iio.h"
+#include "../sysfs.h"
+#include "dac.h"
+#include "ad5791.h"
+
+static int ad5791_spi_write(struct spi_device *spi, u8 addr, u32 val)
+{
+ union {
+ u32 d32;
+ u8 d8[4];
+ } data;
+
+ data.d32 = cpu_to_be32(AD5791_CMD_WRITE |
+ AD5791_ADDR(addr) |
+ (val & AD5791_DAC_MASK));
+
+ return spi_write(spi, &data.d8[1], 3);
+}
+
+static int ad5791_spi_read(struct spi_device *spi, u8 addr, u32 *val)
+{
+ union {
+ u32 d32;
+ u8 d8[4];
+ } data[3];
+ int ret;
+ struct spi_message msg;
+ struct spi_transfer xfers[] = {
+ {
+ .tx_buf = &data[0].d8[1],
+ .bits_per_word = 8,
+ .len = 3,
+ .cs_change = 1,
+ }, {
+ .tx_buf = &data[1].d8[1],
+ .rx_buf = &data[2].d8[1],
+ .bits_per_word = 8,
+ .len = 3,
+ },
+ };
+
+ data[0].d32 = cpu_to_be32(AD5791_CMD_READ |
+ AD5791_ADDR(addr));
+ data[1].d32 = cpu_to_be32(AD5791_ADDR(AD5791_ADDR_NOOP));
+
+ spi_message_init(&msg);
+ spi_message_add_tail(&xfers[0], &msg);
+ spi_message_add_tail(&xfers[1], &msg);
+ ret = spi_sync(spi, &msg);
+
+ *val = be32_to_cpu(data[2].d32);
+
+ return ret;
+}
+
+static ssize_t ad5791_write_dac(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ad5791_state *st = iio_dev_get_devdata(indio_dev);
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+ long readin;
+ int ret;
+
+ ret = strict_strtol(buf, 10, &readin);
+ if (ret)
+ return ret;
+
+ readin += (1 << (st->chip_info->bits - 1));
+ readin &= AD5791_RES_MASK(st->chip_info->bits);
+ readin <<= st->chip_info->left_shift;
+
+ ret = ad5791_spi_write(st->spi, this_attr->address, readin);
+ return ret ? ret : len;
+}
+
+static ssize_t ad5791_read_dac(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ad5791_state *st = iio_dev_get_devdata(indio_dev);
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+ int ret;
+ int val;
+
+ ret = ad5791_spi_read(st->spi, this_attr->address, &val);
+ if (ret)
+ return ret;
+
+ val &= AD5791_DAC_MASK;
+ val >>= st->chip_info->left_shift;
+ val -= (1 << (st->chip_info->bits - 1));
+
+ return sprintf(buf, "%d\n", val);
+}
+
+static ssize_t ad5791_read_powerdown_mode(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ad5791_state *st = iio_dev_get_devdata(indio_dev);
+
+ const char mode[][14] = {"6kohm_to_gnd", "three_state"};
+
+ return sprintf(buf, "%s\n", mode[st->pwr_down_mode]);
+}
+
+static ssize_t ad5791_write_powerdown_mode(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ad5791_state *st = iio_dev_get_devdata(indio_dev);
+ int ret;
+
+ if (sysfs_streq(buf, "6kohm_to_gnd"))
+ st->pwr_down_mode = AD5791_DAC_PWRDN_6K;
+ else if (sysfs_streq(buf, "three_state"))
+ st->pwr_down_mode = AD5791_DAC_PWRDN_3STATE;
+ else
+ ret = -EINVAL;
+
+ return ret ? ret : len;
+}
+
+static ssize_t ad5791_read_dac_powerdown(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ad5791_state *st = iio_dev_get_devdata(indio_dev);
+
+ return sprintf(buf, "%d\n", st->pwr_down);
+}
+
+static ssize_t ad5791_write_dac_powerdown(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t len)
+{
+ long readin;
+ int ret;
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ad5791_state *st = iio_dev_get_devdata(indio_dev);
+
+ ret = strict_strtol(buf, 10, &readin);
+ if (ret)
+ return ret;
+
+ if (readin == 0) {
+ st->pwr_down = false;
+ st->ctrl &= ~(AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
+ } else if (readin == 1) {
+ st->pwr_down = true;
+ if (st->pwr_down_mode == AD5791_DAC_PWRDN_6K)
+ st->ctrl |= AD5791_CTRL_OPGND;
+ else if (st->pwr_down_mode == AD5791_DAC_PWRDN_3STATE)
+ st->ctrl |= AD5791_CTRL_DACTRI;
+ } else
+ ret = -EINVAL;
+
+ ret = ad5791_spi_write(st->spi, AD5791_ADDR_CTRL, st->ctrl);
+
+ return ret ? ret : len;
+}
+
+static ssize_t ad5791_show_scale(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ad5791_state *st = iio_dev_get_devdata(indio_dev);
+ /* Corresponds to Vref / 2^(bits) */
+ unsigned int scale_uv = (st->vref_mv * 1000) >> st->chip_info->bits;
+
+ return sprintf(buf, "%d.%03d\n", scale_uv / 1000, scale_uv % 1000);
+}
+static IIO_DEVICE_ATTR(out_scale, S_IRUGO, ad5791_show_scale, NULL, 0);
+
+static ssize_t ad5791_show_name(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct ad5791_state *st = iio_dev_get_devdata(indio_dev);
+
+ return sprintf(buf, "%s\n", spi_get_device_id(st->spi)->name);
+}
+static IIO_DEVICE_ATTR(name, S_IRUGO, ad5791_show_name, NULL, 0);
+
+#define IIO_DEV_ATTR_OUT_RW_RAW(_num, _show, _store, _addr) \
+ IIO_DEVICE_ATTR(out##_num##_raw, \
+ S_IRUGO | S_IWUSR, _show, _store, _addr)
+
+static IIO_DEV_ATTR_OUT_RW_RAW(0, ad5791_read_dac,
+ ad5791_write_dac, AD5791_ADDR_DAC0);
+
+static IIO_DEVICE_ATTR(out_powerdown_mode, S_IRUGO |
+ S_IWUSR, ad5791_read_powerdown_mode,
+ ad5791_write_powerdown_mode, 0);
+
+static IIO_CONST_ATTR(out_powerdown_mode_available,
+ "6kohm_to_gnd three_state");
+
+#define IIO_DEV_ATTR_DAC_POWERDOWN(_num, _show, _store, _addr) \
+ IIO_DEVICE_ATTR(out##_num##_powerdown, \
+ S_IRUGO | S_IWUSR, _show, _store, _addr)
+
+static IIO_DEV_ATTR_DAC_POWERDOWN(0, ad5791_read_dac_powerdown,
+ ad5791_write_dac_powerdown, 0);
+
+static struct attribute *ad5791_attributes[] = {
+ &iio_dev_attr_out0_raw.dev_attr.attr,
+ &iio_dev_attr_out0_powerdown.dev_attr.attr,
+ &iio_dev_attr_out_powerdown_mode.dev_attr.attr,
+ &iio_const_attr_out_powerdown_mode_available.dev_attr.attr,
+ &iio_dev_attr_out_scale.dev_attr.attr,
+ &iio_dev_attr_name.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group ad5791_attribute_group = {
+ .attrs = ad5791_attributes,
+};
+
+static const struct ad5791_chip_info ad5791_chip_info_tbl[] = {
+ [ID_AD5791] = {
+ .bits = 20,
+ .left_shift = 0,
+ },
+ [ID_AD5781] = {
+ .bits = 18,
+ .left_shift = 2,
+ },
+};
+
+static int ad5791_get_lin_comp(unsigned int span)
+{
+ if (span <= 10000)
+ return AD5791_LINCOMP_0_10;
+ else if (span <= 12000)
+ return AD5791_LINCOMP_10_12;
+ else if (span <= 16000)
+ return AD5791_LINCOMP_12_16;
+ else if (span <= 19000)
+ return AD5791_LINCOMP_16_19;
+ else
+ return AD5791_LINCOMP_19_20;
+}
+
+static int __devinit ad5791_probe(struct spi_device *spi)
+{
+ struct ad5791_platform_data *pdata = spi->dev.platform_data;
+ struct ad5791_state *st;
+ int ret, pos_voltage_uv = 0, neg_voltage_uv = 0;
+
+ st = kzalloc(sizeof(*st), GFP_KERNEL);
+ if (st == NULL) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+
+ spi_set_drvdata(spi, st);
+
+ st->reg_vdd = regulator_get(&spi->dev, "vdd");
+ if (!IS_ERR(st->reg_vdd)) {
+ ret = regulator_enable(st->reg_vdd);
+ if (ret)
+ goto error_put_reg_pos;
+
+ pos_voltage_uv = regulator_get_voltage(st->reg_vdd);
+ }
+
+ st->reg_vss = regulator_get(&spi->dev, "vss");
+ if (!IS_ERR(st->reg_vss)) {
+ ret = regulator_enable(st->reg_vss);
+ if (ret)
+ goto error_put_reg_neg;
+
+ neg_voltage_uv = regulator_get_voltage(st->reg_vss);
+ }
+
+ if (!IS_ERR(st->reg_vss) && !IS_ERR(st->reg_vdd))
+ st->vref_mv = (pos_voltage_uv - neg_voltage_uv) / 1000;
+ else if (pdata)
+ st->vref_mv = pdata->vref_pos_mv - pdata->vref_neg_mv;
+ else
+ dev_warn(&spi->dev, "reference voltage unspecified\n");
+
+ ret = ad5791_spi_write(spi, AD5791_ADDR_SW_CTRL, AD5791_SWCTRL_RESET);
+ if (ret)
+ goto error_disable_reg_neg;
+
+ st->chip_info =
+ &ad5791_chip_info_tbl[spi_get_device_id(spi)->driver_data];
+
+
+ st->ctrl = AD5761_CTRL_LINCOMP(ad5791_get_lin_comp(st->vref_mv)) |
+ ((pdata && pdata->use_rbuf_gain2) ? 0 : AD5791_CTRL_RBUF) |
+ AD5791_CTRL_BIN2SC;
+
+ ret = ad5791_spi_write(spi, AD5791_ADDR_CTRL, st->ctrl |
+ AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI);
+ if (ret)
+ goto error_disable_reg_neg;
+
+ st->pwr_down = true;
+
+ st->spi = spi;
+ st->indio_dev = iio_allocate_device();
+ if (st->indio_dev == NULL) {
+ ret = -ENOMEM;
+ goto error_disable_reg_neg;
+ }
+ st->indio_dev->dev.parent = &spi->dev;
+ st->indio_dev->dev_data = (void *)(st);
+ st->indio_dev->attrs = &ad5791_attribute_group;
+ st->indio_dev->driver_module = THIS_MODULE;
+ st->indio_dev->modes = INDIO_DIRECT_MODE;
+
+ ret = iio_device_register(st->indio_dev);
+ if (ret)
+ goto error_free_dev;
+
+ return 0;
+
+error_free_dev:
+ iio_free_device(st->indio_dev);
+
+error_disable_reg_neg:
+ if (!IS_ERR(st->reg_vss))
+ regulator_disable(st->reg_vss);
+error_put_reg_neg:
+ if (!IS_ERR(st->reg_vss))
+ regulator_put(st->reg_vss);
+
+ if (!IS_ERR(st->reg_vdd))
+ regulator_disable(st->reg_vdd);
+error_put_reg_pos:
+ if (!IS_ERR(st->reg_vdd))
+ regulator_put(st->reg_vdd);
+
+ kfree(st);
+error_ret:
+ return ret;
+}
+
+static int __devexit ad5791_remove(struct spi_device *spi)
+{
+ struct ad5791_state *st = spi_get_drvdata(spi);
+
+ iio_device_unregister(st->indio_dev);
+
+ if (!IS_ERR(st->reg_vdd)) {
+ regulator_disable(st->reg_vdd);
+ regulator_put(st->reg_vdd);
+ }
+
+ if (!IS_ERR(st->reg_vss)) {
+ regulator_disable(st->reg_vss);
+ regulator_put(st->reg_vss);
+ }
+
+ kfree(st);
+
+ return 0;
+}
+
+static const struct spi_device_id ad5791_id[] = {
+ {"ad5791", ID_AD5791},
+ {"ad5781", ID_AD5781},
+ {}
+};
+
+static struct spi_driver ad5791_driver = {
+ .driver = {
+ .name = "ad5791",
+ .owner = THIS_MODULE,
+ },
+ .probe = ad5791_probe,
+ .remove = __devexit_p(ad5791_remove),
+ .id_table = ad5791_id,
+};
+
+static __init int ad5791_spi_init(void)
+{
+ return spi_register_driver(&ad5791_driver);
+}
+module_init(ad5791_spi_init);
+
+static __exit void ad5791_spi_exit(void)
+{
+ spi_unregister_driver(&ad5791_driver);
+}
+module_exit(ad5791_spi_exit);
+
+MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
+MODULE_DESCRIPTION("Analog Devices AD5791/AD5781 DAC");
+MODULE_LICENSE("GPL v2");
--- /dev/null
+/*
+ * AD5791 SPI DAC driver
+ *
+ * Copyright 2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+
+#ifndef SPI_AD5791_H_
+#define SPI_AD5791_H_
+
+#define AD5791_RES_MASK(x) ((1 << (x)) - 1)
+#define AD5791_DAC_MASK AD5791_RES_MASK(20)
+#define AD5791_DAC_MSB (1 << 19)
+
+#define AD5791_CMD_READ (1 << 23)
+#define AD5791_CMD_WRITE (0 << 23)
+#define AD5791_ADDR(addr) ((addr) << 20)
+
+/* Registers */
+#define AD5791_ADDR_NOOP 0
+#define AD5791_ADDR_DAC0 1
+#define AD5791_ADDR_CTRL 2
+#define AD5791_ADDR_CLRCODE 3
+#define AD5791_ADDR_SW_CTRL 4
+
+/* Control Register */
+#define AD5791_CTRL_RBUF (1 << 1)
+#define AD5791_CTRL_OPGND (1 << 2)
+#define AD5791_CTRL_DACTRI (1 << 3)
+#define AD5791_CTRL_BIN2SC (1 << 4)
+#define AD5791_CTRL_SDODIS (1 << 5)
+#define AD5761_CTRL_LINCOMP(x) ((x) << 6)
+
+#define AD5791_LINCOMP_0_10 0
+#define AD5791_LINCOMP_10_12 1
+#define AD5791_LINCOMP_12_16 2
+#define AD5791_LINCOMP_16_19 3
+#define AD5791_LINCOMP_19_20 12
+
+/* Software Control Register */
+#define AD5791_SWCTRL_LDAC (1 << 0)
+#define AD5791_SWCTRL_CLR (1 << 1)
+#define AD5791_SWCTRL_RESET (1 << 2)
+
+#define AD5791_DAC_PWRDN_6K 0
+#define AD5791_DAC_PWRDN_3STATE 1
+
+/*
+ * TODO: struct ad5791_platform_data needs to go into include/linux/iio
+ */
+
+/**
+ * struct ad5791_platform_data - platform specific information
+ * @vref_pos_mv: Vdd Positive Analog Supply Volatge (mV)
+ * @vref_neg_mv: Vdd Negative Analog Supply Volatge (mV)
+ * @use_rbuf_gain2: ext. amplifier connected in gain of two configuration
+ */
+
+struct ad5791_platform_data {
+ u16 vref_pos_mv;
+ u16 vref_neg_mv;
+ bool use_rbuf_gain2;
+};
+
+/**
+ * struct ad5791_chip_info - chip specific information
+ * @bits: accuracy of the DAC in bits
+ * @left_shift: number of bits the datum must be shifted
+ */
+
+struct ad5791_chip_info {
+ u8 bits;
+ u8 left_shift;
+};
+
+/**
+ * struct ad5791_state - driver instance specific data
+ * @indio_dev: the industrial I/O device
+ * @us: spi_device
+ * @reg_vdd: positive supply regulator
+ * @reg_vss: negative supply regulator
+ * @chip_info: chip model specific constants
+ * @vref_mv: actual reference voltage used
+ * @pwr_down_mode current power down mode
+ */
+
+struct ad5791_state {
+ struct iio_dev *indio_dev;
+ struct spi_device *spi;
+ struct regulator *reg_vdd;
+ struct regulator *reg_vss;
+ const struct ad5791_chip_info *chip_info;
+ unsigned short vref_mv;
+ unsigned ctrl;
+ unsigned pwr_down_mode;
+ bool pwr_down;
+};
+
+/**
+ * ad5791_supported_device_ids:
+ */
+
+enum ad5791_supported_device_ids {
+ ID_AD5791,
+ ID_AD5781,
+};
+
+#endif /* SPI_AD5791_H_ */
projects / linux-beck.git / commitdiff