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authorNaveen Krishna Chatradhi <ch.naveen@samsung.com>2013-03-13 09:38:20 +0530
committerGuenter Roeck <linux@roeck-us.net>2013-04-07 21:16:38 -0700
commit9e8269de100dd0be1199778dc175ff22417aebd2 (patch)
tree743aa1c1d90be98c11d297e055c557162e98d8c3 /drivers/hwmon
parent4b5e536b0e948b5c756aa1d57218371c242f768d (diff)
downloadlinux-9e8269de100dd0be1199778dc175ff22417aebd2.tar.gz
hwmon: (ntc_thermistor) Add DT with IIO support to NTC thermistor driver
This patch adds DT support to NTC driver to parse the platform data. Also adds the support to work as an iio device client. During the probe ntc driver gets the respective channels of ADC and uses iio_raw_read calls to get the ADC converted value. Signed-off-by: Naveen Krishna Chatradhi <ch.naveen@samsung.com> [Guenter Roeck: fixed Kconfig dependencies; use ERR_CAST] Tested-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
-rw-r--r--drivers/hwmon/Kconfig1
-rw-r--r--drivers/hwmon/ntc_thermistor.c145
2 files changed, 127 insertions, 19 deletions
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index aaa14f4a0f7..47d2176957a 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -899,6 +899,7 @@ config SENSORS_MCP3021
config SENSORS_NTC_THERMISTOR
tristate "NTC thermistor support"
+ depends on (!OF && !IIO) || (OF && IIO)
help
This driver supports NTC thermistors sensor reading and its
interpretation. The driver can also monitor the temperature and
diff --git a/drivers/hwmon/ntc_thermistor.c b/drivers/hwmon/ntc_thermistor.c
index b5f63f9c0ce..d399197655e 100644
--- a/drivers/hwmon/ntc_thermistor.c
+++ b/drivers/hwmon/ntc_thermistor.c
@@ -26,9 +26,16 @@
#include <linux/math64.h>
#include <linux/platform_device.h>
#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/platform_data/ntc_thermistor.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/machine.h>
+#include <linux/iio/driver.h>
+#include <linux/iio/consumer.h>
+
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
@@ -37,6 +44,15 @@ struct ntc_compensation {
unsigned int ohm;
};
+static const struct platform_device_id ntc_thermistor_id[] = {
+ { "ncp15wb473", TYPE_NCPXXWB473 },
+ { "ncp18wb473", TYPE_NCPXXWB473 },
+ { "ncp21wb473", TYPE_NCPXXWB473 },
+ { "ncp03wb473", TYPE_NCPXXWB473 },
+ { "ncp15wl333", TYPE_NCPXXWL333 },
+ { },
+};
+
/*
* A compensation table should be sorted by the values of .ohm
* in descending order.
@@ -125,6 +141,92 @@ struct ntc_data {
char name[PLATFORM_NAME_SIZE];
};
+#ifdef CONFIG_OF
+static int ntc_adc_iio_read(struct ntc_thermistor_platform_data *pdata)
+{
+ struct iio_channel *channel = pdata->chan;
+ unsigned int result;
+ int val, ret;
+
+ ret = iio_read_channel_raw(channel, &val);
+ if (ret < 0) {
+ pr_err("read channel() error: %d\n", ret);
+ return ret;
+ }
+
+ /* unit: mV */
+ result = pdata->pullup_uV * val;
+ result >>= 12;
+
+ return result;
+}
+
+static const struct of_device_id ntc_match[] = {
+ { .compatible = "ntc,ncp15wb473",
+ .data = &ntc_thermistor_id[TYPE_NCPXXWB473] },
+ { .compatible = "ntc,ncp18wb473",
+ .data = &ntc_thermistor_id[TYPE_NCPXXWB473] },
+ { .compatible = "ntc,ncp21wb473",
+ .data = &ntc_thermistor_id[TYPE_NCPXXWB473] },
+ { .compatible = "ntc,ncp03wb473",
+ .data = &ntc_thermistor_id[TYPE_NCPXXWB473] },
+ { .compatible = "ntc,ncp15wl333",
+ .data = &ntc_thermistor_id[TYPE_NCPXXWL333] },
+ { },
+};
+MODULE_DEVICE_TABLE(of, ntc_match);
+
+static struct ntc_thermistor_platform_data *
+ntc_thermistor_parse_dt(struct platform_device *pdev)
+{
+ struct iio_channel *chan;
+ struct device_node *np = pdev->dev.of_node;
+ struct ntc_thermistor_platform_data *pdata;
+
+ if (!np)
+ return NULL;
+
+ pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
+ if (!pdata)
+ return ERR_PTR(-ENOMEM);
+
+ chan = iio_channel_get(&pdev->dev, NULL);
+ if (IS_ERR(chan))
+ return ERR_CAST(chan);
+
+ if (of_property_read_u32(np, "pullup-uv", &pdata->pullup_uV))
+ return ERR_PTR(-ENODEV);
+ if (of_property_read_u32(np, "pullup-ohm", &pdata->pullup_ohm))
+ return ERR_PTR(-ENODEV);
+ if (of_property_read_u32(np, "pulldown-ohm", &pdata->pulldown_ohm))
+ return ERR_PTR(-ENODEV);
+
+ if (of_find_property(np, "connected-positive", NULL))
+ pdata->connect = NTC_CONNECTED_POSITIVE;
+ else /* status change should be possible if not always on. */
+ pdata->connect = NTC_CONNECTED_GROUND;
+
+ pdata->chan = chan;
+ pdata->read_uV = ntc_adc_iio_read;
+
+ return pdata;
+}
+static void ntc_iio_channel_release(struct ntc_thermistor_platform_data *pdata)
+{
+ if (pdata->chan)
+ iio_channel_release(pdata->chan);
+}
+#else
+static struct ntc_thermistor_platform_data *
+ntc_thermistor_parse_dt(struct platform_device *pdev)
+{
+ return NULL;
+}
+
+static void ntc_iio_channel_release(struct ntc_thermistor_platform_data *pdata)
+{ }
+#endif
+
static inline u64 div64_u64_safe(u64 dividend, u64 divisor)
{
if (divisor == 0 && dividend == 0)
@@ -259,7 +361,7 @@ static int ntc_thermistor_get_ohm(struct ntc_data *data)
return data->pdata->read_ohm();
if (data->pdata->read_uV) {
- read_uV = data->pdata->read_uV();
+ read_uV = data->pdata->read_uV(data->pdata);
if (read_uV < 0)
return read_uV;
return get_ohm_of_thermistor(data, read_uV);
@@ -311,9 +413,18 @@ static const struct attribute_group ntc_attr_group = {
static int ntc_thermistor_probe(struct platform_device *pdev)
{
+ const struct of_device_id *of_id =
+ of_match_device(of_match_ptr(ntc_match), &pdev->dev);
+ const struct platform_device_id *pdev_id;
+ struct ntc_thermistor_platform_data *pdata;
struct ntc_data *data;
- struct ntc_thermistor_platform_data *pdata = pdev->dev.platform_data;
- int ret = 0;
+ int ret;
+
+ pdata = ntc_thermistor_parse_dt(pdev);
+ if (IS_ERR(pdata))
+ return PTR_ERR(pdata);
+ else if (pdata == NULL)
+ pdata = pdev->dev.platform_data;
if (!pdata) {
dev_err(&pdev->dev, "No platform init data supplied.\n");
@@ -349,11 +460,13 @@ static int ntc_thermistor_probe(struct platform_device *pdev)
if (!data)
return -ENOMEM;
+ pdev_id = of_id ? of_id->data : platform_get_device_id(pdev);
+
data->dev = &pdev->dev;
data->pdata = pdata;
- strlcpy(data->name, pdev->id_entry->name, sizeof(data->name));
+ strlcpy(data->name, pdev_id->name, sizeof(data->name));
- switch (pdev->id_entry->driver_data) {
+ switch (pdev_id->driver_data) {
case TYPE_NCPXXWB473:
data->comp = ncpXXwb473;
data->n_comp = ARRAY_SIZE(ncpXXwb473);
@@ -364,8 +477,7 @@ static int ntc_thermistor_probe(struct platform_device *pdev)
break;
default:
dev_err(&pdev->dev, "Unknown device type: %lu(%s)\n",
- pdev->id_entry->driver_data,
- pdev->id_entry->name);
+ pdev_id->driver_data, pdev_id->name);
return -EINVAL;
}
@@ -384,39 +496,34 @@ static int ntc_thermistor_probe(struct platform_device *pdev)
goto err_after_sysfs;
}
- dev_info(&pdev->dev, "Thermistor %s:%d (type: %s/%lu) successfully probed.\n",
- pdev->name, pdev->id, pdev->id_entry->name,
- pdev->id_entry->driver_data);
+ dev_info(&pdev->dev, "Thermistor type: %s successfully probed.\n",
+ pdev->name);
+
return 0;
err_after_sysfs:
sysfs_remove_group(&data->dev->kobj, &ntc_attr_group);
+ ntc_iio_channel_release(pdata);
return ret;
}
static int ntc_thermistor_remove(struct platform_device *pdev)
{
struct ntc_data *data = platform_get_drvdata(pdev);
+ struct ntc_thermistor_platform_data *pdata = data->pdata;
hwmon_device_unregister(data->hwmon_dev);
sysfs_remove_group(&data->dev->kobj, &ntc_attr_group);
+ ntc_iio_channel_release(pdata);
platform_set_drvdata(pdev, NULL);
return 0;
}
-static const struct platform_device_id ntc_thermistor_id[] = {
- { "ncp15wb473", TYPE_NCPXXWB473 },
- { "ncp18wb473", TYPE_NCPXXWB473 },
- { "ncp21wb473", TYPE_NCPXXWB473 },
- { "ncp03wb473", TYPE_NCPXXWB473 },
- { "ncp15wl333", TYPE_NCPXXWL333 },
- { },
-};
-
static struct platform_driver ntc_thermistor_driver = {
.driver = {
.name = "ntc-thermistor",
.owner = THIS_MODULE,
+ .of_match_table = of_match_ptr(ntc_match),
},
.probe = ntc_thermistor_probe,
.remove = ntc_thermistor_remove,