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-rw-r--r--drivers/iio/dac/Kconfig10
-rw-r--r--drivers/iio/dac/Makefile1
-rw-r--r--drivers/iio/dac/ad5592r.c2
-rw-r--r--drivers/iio/dac/dpot-dac.c266
-rw-r--r--drivers/iio/dac/mcp4725.c176
5 files changed, 438 insertions, 17 deletions
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index 120b24478469..d3084028905b 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -200,6 +200,16 @@ config AD8801
To compile this driver as a module choose M here: the module will be called
ad8801.
+config DPOT_DAC
+ tristate "DAC emulation using a DPOT"
+ depends on OF
+ help
+ Say yes here to build support for DAC emulation using a digital
+ potentiometer.
+
+ To compile this driver as a module, choose M here: the module will be
+ called dpot-dac.
+
config LPC18XX_DAC
tristate "NXP LPC18xx DAC driver"
depends on ARCH_LPC18XX || COMPILE_TEST
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 27642bbf75f2..f01bf4a99867 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_AD5686) += ad5686.o
obj-$(CONFIG_AD7303) += ad7303.o
obj-$(CONFIG_AD8801) += ad8801.o
obj-$(CONFIG_CIO_DAC) += cio-dac.o
+obj-$(CONFIG_DPOT_DAC) += dpot-dac.o
obj-$(CONFIG_LPC18XX_DAC) += lpc18xx_dac.o
obj-$(CONFIG_M62332) += m62332.o
obj-$(CONFIG_MAX517) += max517.o
diff --git a/drivers/iio/dac/ad5592r.c b/drivers/iio/dac/ad5592r.c
index 0b235a2c7359..6eed5b7729be 100644
--- a/drivers/iio/dac/ad5592r.c
+++ b/drivers/iio/dac/ad5592r.c
@@ -17,7 +17,7 @@
#define AD5592R_GPIO_READBACK_EN BIT(10)
#define AD5592R_LDAC_READBACK_EN BIT(6)
-static int ad5592r_spi_wnop_r16(struct ad5592r_state *st, u16 *buf)
+static int ad5592r_spi_wnop_r16(struct ad5592r_state *st, __be16 *buf)
{
struct spi_device *spi = container_of(st->dev, struct spi_device, dev);
struct spi_transfer t = {
diff --git a/drivers/iio/dac/dpot-dac.c b/drivers/iio/dac/dpot-dac.c
new file mode 100644
index 000000000000..960a2b430480
--- /dev/null
+++ b/drivers/iio/dac/dpot-dac.c
@@ -0,0 +1,266 @@
+/*
+ * IIO DAC emulation driver using a digital potentiometer
+ *
+ * Copyright (C) 2016 Axentia Technologies AB
+ *
+ * Author: Peter Rosin <peda@axentia.se>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+/*
+ * It is assumed that the dpot is used as a voltage divider between the
+ * current dpot wiper setting and the maximum resistance of the dpot. The
+ * divided voltage is provided by a vref regulator.
+ *
+ * .------.
+ * .-----------. | |
+ * | vref |--' .---.
+ * | regulator |--. | |
+ * '-----------' | | d |
+ * | | p |
+ * | | o | wiper
+ * | | t |<---------+
+ * | | |
+ * | '---' dac output voltage
+ * | |
+ * '------+------------+
+ */
+
+#include <linux/err.h>
+#include <linux/iio/consumer.h>
+#include <linux/iio/iio.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
+
+struct dpot_dac {
+ struct regulator *vref;
+ struct iio_channel *dpot;
+ u32 max_ohms;
+};
+
+static const struct iio_chan_spec dpot_dac_iio_channel = {
+ .type = IIO_VOLTAGE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW)
+ | BIT(IIO_CHAN_INFO_SCALE),
+ .info_mask_separate_available = BIT(IIO_CHAN_INFO_RAW),
+ .output = 1,
+ .indexed = 1,
+};
+
+static int dpot_dac_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct dpot_dac *dac = iio_priv(indio_dev);
+ int ret;
+ unsigned long long tmp;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ return iio_read_channel_raw(dac->dpot, val);
+
+ case IIO_CHAN_INFO_SCALE:
+ ret = iio_read_channel_scale(dac->dpot, val, val2);
+ switch (ret) {
+ case IIO_VAL_FRACTIONAL_LOG2:
+ tmp = *val * 1000000000LL;
+ do_div(tmp, dac->max_ohms);
+ tmp *= regulator_get_voltage(dac->vref) / 1000;
+ do_div(tmp, 1000000000LL);
+ *val = tmp;
+ return ret;
+ case IIO_VAL_INT:
+ /*
+ * Convert integer scale to fractional scale by
+ * setting the denominator (val2) to one...
+ */
+ *val2 = 1;
+ ret = IIO_VAL_FRACTIONAL;
+ /* ...and fall through. */
+ case IIO_VAL_FRACTIONAL:
+ *val *= regulator_get_voltage(dac->vref) / 1000;
+ *val2 *= dac->max_ohms;
+ break;
+ }
+
+ return ret;
+ }
+
+ return -EINVAL;
+}
+
+static int dpot_dac_read_avail(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ const int **vals, int *type, int *length,
+ long mask)
+{
+ struct dpot_dac *dac = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ *type = IIO_VAL_INT;
+ return iio_read_avail_channel_raw(dac->dpot, vals, length);
+ }
+
+ return -EINVAL;
+}
+
+static int dpot_dac_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long mask)
+{
+ struct dpot_dac *dac = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+ return iio_write_channel_raw(dac->dpot, val);
+ }
+
+ return -EINVAL;
+}
+
+static const struct iio_info dpot_dac_info = {
+ .read_raw = dpot_dac_read_raw,
+ .read_avail = dpot_dac_read_avail,
+ .write_raw = dpot_dac_write_raw,
+ .driver_module = THIS_MODULE,
+};
+
+static int dpot_dac_channel_max_ohms(struct iio_dev *indio_dev)
+{
+ struct device *dev = &indio_dev->dev;
+ struct dpot_dac *dac = iio_priv(indio_dev);
+ unsigned long long tmp;
+ int ret;
+ int val;
+ int val2;
+ int max;
+
+ ret = iio_read_max_channel_raw(dac->dpot, &max);
+ if (ret < 0) {
+ dev_err(dev, "dpot does not indicate its raw maximum value\n");
+ return ret;
+ }
+
+ switch (iio_read_channel_scale(dac->dpot, &val, &val2)) {
+ case IIO_VAL_INT:
+ return max * val;
+ case IIO_VAL_FRACTIONAL:
+ tmp = (unsigned long long)max * val;
+ do_div(tmp, val2);
+ return tmp;
+ case IIO_VAL_FRACTIONAL_LOG2:
+ tmp = val * 1000000000LL * max >> val2;
+ do_div(tmp, 1000000000LL);
+ return tmp;
+ default:
+ dev_err(dev, "dpot has a scale that is too weird\n");
+ }
+
+ return -EINVAL;
+}
+
+static int dpot_dac_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct iio_dev *indio_dev;
+ struct dpot_dac *dac;
+ enum iio_chan_type type;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(dev, sizeof(*dac));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, indio_dev);
+ dac = iio_priv(indio_dev);
+
+ indio_dev->name = dev_name(dev);
+ indio_dev->dev.parent = dev;
+ indio_dev->info = &dpot_dac_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = &dpot_dac_iio_channel;
+ indio_dev->num_channels = 1;
+
+ dac->vref = devm_regulator_get(dev, "vref");
+ if (IS_ERR(dac->vref)) {
+ if (PTR_ERR(dac->vref) != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "failed to get vref regulator\n");
+ return PTR_ERR(dac->vref);
+ }
+
+ dac->dpot = devm_iio_channel_get(dev, "dpot");
+ if (IS_ERR(dac->dpot)) {
+ if (PTR_ERR(dac->dpot) != -EPROBE_DEFER)
+ dev_err(dev, "failed to get dpot input channel\n");
+ return PTR_ERR(dac->dpot);
+ }
+
+ ret = iio_get_channel_type(dac->dpot, &type);
+ if (ret < 0)
+ return ret;
+
+ if (type != IIO_RESISTANCE) {
+ dev_err(dev, "dpot is of the wrong type\n");
+ return -EINVAL;
+ }
+
+ ret = dpot_dac_channel_max_ohms(indio_dev);
+ if (ret < 0)
+ return ret;
+ dac->max_ohms = ret;
+
+ ret = regulator_enable(dac->vref);
+ if (ret) {
+ dev_err(dev, "failed to enable the vref regulator\n");
+ return ret;
+ }
+
+ ret = iio_device_register(indio_dev);
+ if (ret) {
+ dev_err(dev, "failed to register iio device\n");
+ goto disable_reg;
+ }
+
+ return 0;
+
+disable_reg:
+ regulator_disable(dac->vref);
+ return ret;
+}
+
+static int dpot_dac_remove(struct platform_device *pdev)
+{
+ struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+ struct dpot_dac *dac = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+ regulator_disable(dac->vref);
+
+ return 0;
+}
+
+static const struct of_device_id dpot_dac_match[] = {
+ { .compatible = "dpot-dac" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, dpot_dac_match);
+
+static struct platform_driver dpot_dac_driver = {
+ .probe = dpot_dac_probe,
+ .remove = dpot_dac_remove,
+ .driver = {
+ .name = "iio-dpot-dac",
+ .of_match_table = dpot_dac_match,
+ },
+};
+module_platform_driver(dpot_dac_driver);
+
+MODULE_DESCRIPTION("DAC emulation driver using a digital potentiometer");
+MODULE_AUTHOR("Peter Rosin <peda@axentia.se>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/iio/dac/mcp4725.c b/drivers/iio/dac/mcp4725.c
index cca935c06f2b..db109f0cdd8c 100644
--- a/drivers/iio/dac/mcp4725.c
+++ b/drivers/iio/dac/mcp4725.c
@@ -18,6 +18,8 @@
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/delay.h>
+#include <linux/regulator/consumer.h>
+#include <linux/of.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
@@ -26,12 +28,20 @@
#define MCP4725_DRV_NAME "mcp4725"
+#define MCP472X_REF_VDD 0x00
+#define MCP472X_REF_VREF_UNBUFFERED 0x02
+#define MCP472X_REF_VREF_BUFFERED 0x03
+
struct mcp4725_data {
struct i2c_client *client;
- u16 vref_mv;
+ int id;
+ unsigned ref_mode;
+ bool vref_buffered;
u16 dac_value;
bool powerdown;
unsigned powerdown_mode;
+ struct regulator *vdd_reg;
+ struct regulator *vref_reg;
};
static int mcp4725_suspend(struct device *dev)
@@ -86,6 +96,7 @@ static ssize_t mcp4725_store_eeprom(struct device *dev,
return 0;
inoutbuf[0] = 0x60; /* write EEPROM */
+ inoutbuf[0] |= data->ref_mode << 3;
inoutbuf[1] = data->dac_value >> 4;
inoutbuf[2] = (data->dac_value & 0xf) << 4;
@@ -278,18 +289,49 @@ static int mcp4725_set_value(struct iio_dev *indio_dev, int val)
return 0;
}
+static int mcp4726_set_cfg(struct iio_dev *indio_dev)
+{
+ struct mcp4725_data *data = iio_priv(indio_dev);
+ u8 outbuf[3];
+ int ret;
+
+ outbuf[0] = 0x40;
+ outbuf[0] |= data->ref_mode << 3;
+ if (data->powerdown)
+ outbuf[0] |= data->powerdown << 1;
+ outbuf[1] = data->dac_value >> 4;
+ outbuf[2] = (data->dac_value & 0xf) << 4;
+
+ ret = i2c_master_send(data->client, outbuf, 3);
+ if (ret < 0)
+ return ret;
+ else if (ret != 3)
+ return -EIO;
+ else
+ return 0;
+}
+
static int mcp4725_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val, int *val2, long mask)
{
struct mcp4725_data *data = iio_priv(indio_dev);
+ int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
*val = data->dac_value;
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
- *val = data->vref_mv;
+ if (data->ref_mode == MCP472X_REF_VDD)
+ ret = regulator_get_voltage(data->vdd_reg);
+ else
+ ret = regulator_get_voltage(data->vref_reg);
+
+ if (ret < 0)
+ return ret;
+
+ *val = ret / 1000;
*val2 = 12;
return IIO_VAL_FRACTIONAL_LOG2;
}
@@ -323,27 +365,98 @@ static const struct iio_info mcp4725_info = {
.driver_module = THIS_MODULE,
};
+#ifdef CONFIG_OF
+static int mcp4725_probe_dt(struct device *dev,
+ struct mcp4725_platform_data *pdata)
+{
+ struct device_node *np = dev->of_node;
+
+ if (!np)
+ return -ENODEV;
+
+ /* check if is the vref-supply defined */
+ pdata->use_vref = of_property_read_bool(np, "vref-supply");
+ pdata->vref_buffered =
+ of_property_read_bool(np, "microchip,vref-buffered");
+
+ return 0;
+}
+#else
+static int mcp4725_probe_dt(struct device *dev,
+ struct mcp4725_platform_data *platform_data)
+{
+ return -ENODEV;
+}
+#endif
+
static int mcp4725_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
struct mcp4725_data *data;
struct iio_dev *indio_dev;
- struct mcp4725_platform_data *platform_data = client->dev.platform_data;
- u8 inbuf[3];
+ struct mcp4725_platform_data *pdata, pdata_dt;
+ u8 inbuf[4];
u8 pd;
+ u8 ref;
int err;
- if (!platform_data || !platform_data->vref_mv) {
- dev_err(&client->dev, "invalid platform data");
- return -EINVAL;
- }
-
indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
if (indio_dev == NULL)
return -ENOMEM;
data = iio_priv(indio_dev);
i2c_set_clientdata(client, indio_dev);
data->client = client;
+ data->id = id->driver_data;
+ pdata = dev_get_platdata(&client->dev);
+
+ if (!pdata) {
+ err = mcp4725_probe_dt(&client->dev, &pdata_dt);
+ if (err) {
+ dev_err(&client->dev,
+ "invalid platform or devicetree data");
+ return err;
+ }
+ pdata = &pdata_dt;
+ }
+
+ if (data->id == MCP4725 && pdata->use_vref) {
+ dev_err(&client->dev,
+ "external reference is unavailable on MCP4725");
+ return -EINVAL;
+ }
+
+ if (!pdata->use_vref && pdata->vref_buffered) {
+ dev_err(&client->dev,
+ "buffering is unavailable on the internal reference");
+ return -EINVAL;
+ }
+
+ if (!pdata->use_vref)
+ data->ref_mode = MCP472X_REF_VDD;
+ else
+ data->ref_mode = pdata->vref_buffered ?
+ MCP472X_REF_VREF_BUFFERED :
+ MCP472X_REF_VREF_UNBUFFERED;
+
+ data->vdd_reg = devm_regulator_get(&client->dev, "vdd");
+ if (IS_ERR(data->vdd_reg))
+ return PTR_ERR(data->vdd_reg);
+
+ err = regulator_enable(data->vdd_reg);
+ if (err)
+ return err;
+
+ if (pdata->use_vref) {
+ data->vref_reg = devm_regulator_get(&client->dev, "vref");
+ if (IS_ERR(data->vref_reg)) {
+ err = PTR_ERR(data->vref_reg);
+ goto err_disable_vdd_reg;
+ }
+
+ err = regulator_enable(data->vref_reg);
+ if (err)
+ goto err_disable_vdd_reg;
+ }
indio_dev->dev.parent = &client->dev;
indio_dev->name = id->name;
@@ -352,25 +465,56 @@ static int mcp4725_probe(struct i2c_client *client,
indio_dev->num_channels = 1;
indio_dev->modes = INDIO_DIRECT_MODE;
- data->vref_mv = platform_data->vref_mv;
+ /* read current DAC value and settings */
+ err = i2c_master_recv(client, inbuf, data->id == MCP4725 ? 3 : 4);
- /* read current DAC value */
- err = i2c_master_recv(client, inbuf, 3);
if (err < 0) {
dev_err(&client->dev, "failed to read DAC value");
- return err;
+ goto err_disable_vref_reg;
}
pd = (inbuf[0] >> 1) & 0x3;
data->powerdown = pd > 0 ? true : false;
- data->powerdown_mode = pd ? pd - 1 : 2; /* largest register to gnd */
+ data->powerdown_mode = pd ? pd - 1 : 2; /* largest resistor to gnd */
data->dac_value = (inbuf[1] << 4) | (inbuf[2] >> 4);
+ if (data->id == MCP4726)
+ ref = (inbuf[3] >> 3) & 0x3;
+
+ if (data->id == MCP4726 && ref != data->ref_mode) {
+ dev_info(&client->dev,
+ "voltage reference mode differs (conf: %u, eeprom: %u), setting %u",
+ data->ref_mode, ref, data->ref_mode);
+ err = mcp4726_set_cfg(indio_dev);
+ if (err < 0)
+ goto err_disable_vref_reg;
+ }
+
+ err = iio_device_register(indio_dev);
+ if (err)
+ goto err_disable_vref_reg;
+
+ return 0;
+
+err_disable_vref_reg:
+ if (data->vref_reg)
+ regulator_disable(data->vref_reg);
- return iio_device_register(indio_dev);
+err_disable_vdd_reg:
+ regulator_disable(data->vdd_reg);
+
+ return err;
}
static int mcp4725_remove(struct i2c_client *client)
{
- iio_device_unregister(i2c_get_clientdata(client));
+ struct iio_dev *indio_dev = i2c_get_clientdata(client);
+ struct mcp4725_data *data = iio_priv(indio_dev);
+
+ iio_device_unregister(indio_dev);
+
+ if (data->vref_reg)
+ regulator_disable(data->vref_reg);
+ regulator_disable(data->vdd_reg);
+
return 0;
}
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-11-25 15:39:42 +0000