hwmon: Add driver for ADT7411 voltage and temperature sensor

Add basic support for the ADT7411. Reads out all conversion results (via I2C,
SPI yet missing) and allows some on-the-fly configuration. Tested with a
custom board.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>

4 files changed, 412 insertions, 0 deletions

diff --git a/Documentation/hwmon/adt7411 b/Documentation/hwmon/adt7411
new file mode 100644
index 000000000000..1632960f9745
--- /dev/null
+++ b/Documentation/hwmon/adt7411
@@ -0,0 +1,42 @@
+Kernel driver adt7411
+=====================
+
+Supported chips:
+  * Analog Devices ADT7411
+    Prefix: 'adt7411'
+    Addresses scanned: 0x48, 0x4a, 0x4b
+    Datasheet: Publicly available at the Analog Devices website
+
+Author: Wolfram Sang (based on adt7470 by Darrick J. Wong)
+
+Description
+-----------
+
+This driver implements support for the Analog Devices ADT7411 chip. There may
+be other chips that implement this interface.
+
+The ADT7411 can use an I2C/SMBus compatible 2-wire interface or an
+SPI-compatible 4-wire interface. It provides a 10-bit analog to digital
+converter which measures 1 temperature, vdd and 8 input voltages. It has an
+internal temperature sensor, but an external one can also be connected (one
+loses 2 inputs then). There are high- and low-limit registers for all inputs.
+
+Check the datasheet for details.
+
+sysfs-Interface
+---------------
+
+in0_input       - vdd voltage input
+in[1-8]_input   - analog 1-8 input
+temp1_input     - temperature input
+
+Besides standard interfaces, this driver adds (0 = off, 1 = on):
+
+  adc_ref_vdd   - Use vdd as reference instead of 2.25 V
+  fast_sampling - Sample at 22.5 kHz instead of 1.4 kHz, but drop filters
+  no_average    - Turn off averaging over 16 samples
+
+Notes
+-----
+
+SPI, external temperature sensor and limit registers are not supported yet.
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index cdfb0637f247..77d032fb813d 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -170,6 +170,16 @@ config SENSORS_ADM9240
           This driver can also be built as a module.  If so, the module
           will be called adm9240.
 
+config SENSORS_ADT7411
+        tristate "Analog Devices ADT7411"
+        depends on I2C && EXPERIMENTAL
+        help
+          If you say yes here you get support for the Analog Devices
+          ADT7411 voltage and temperature monitoring chip.
+
+          This driver can also be built as a module. If so, the module
+          will be called adt7411.
+
 config SENSORS_ADT7462
         tristate "Analog Devices ADT7462"
         depends on I2C && EXPERIMENTAL
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 4bc215c0953f..5fe67bf961b3 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_SENSORS_ADM1029)	+= adm1029.o
 obj-$(CONFIG_SENSORS_ADM1031)   += adm1031.o
 obj-$(CONFIG_SENSORS_ADM9240)   += adm9240.o
 obj-$(CONFIG_SENSORS_ADS7828)   += ads7828.o
+obj-$(CONFIG_SENSORS_ADT7411)   += adt7411.o
 obj-$(CONFIG_SENSORS_ADT7462)   += adt7462.o
 obj-$(CONFIG_SENSORS_ADT7470)   += adt7470.o
 obj-$(CONFIG_SENSORS_ADT7473)   += adt7473.o
diff --git a/drivers/hwmon/adt7411.c b/drivers/hwmon/adt7411.c
new file mode 100644
index 000000000000..9e9246fe2245
--- /dev/null
+++ b/drivers/hwmon/adt7411.c
@@ -0,0 +1,359 @@
+/*
+ *  Driver for the ADT7411 (I2C/SPI 8 channel 10 bit ADC & temperature-sensor)
+ *
+ *  Copyright (C) 2008, 2010 Pengutronix
+ *
+ *  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.
+ *
+ *  TODO: SPI, support for external temperature sensor
+ *        use power-down mode for suspend?, interrupt handling?
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/mutex.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+
+#define ADT7411_REG_INT_TEMP_VDD_LSB            0x03
+#define ADT7411_REG_EXT_TEMP_AIN14_LSB          0x04
+#define ADT7411_REG_VDD_MSB                     0x06
+#define ADT7411_REG_INT_TEMP_MSB                0x07
+#define ADT7411_REG_EXT_TEMP_AIN1_MSB           0x08
+
+#define ADT7411_REG_CFG1                        0x18
+#define ADT7411_CFG1_START_MONITOR              (1 << 0)
+
+#define ADT7411_REG_CFG2                        0x19
+#define ADT7411_CFG2_DISABLE_AVG                (1 << 5)
+
+#define ADT7411_REG_CFG3                        0x1a
+#define ADT7411_CFG3_ADC_CLK_225                (1 << 0)
+#define ADT7411_CFG3_REF_VDD                    (1 << 4)
+
+#define ADT7411_REG_DEVICE_ID                   0x4d
+#define ADT7411_REG_MANUFACTURER_ID             0x4e
+
+#define ADT7411_DEVICE_ID                       0x2
+#define ADT7411_MANUFACTURER_ID                 0x41
+
+static const unsigned short normal_i2c[] = { 0x48, 0x4a, 0x4b, I2C_CLIENT_END };
+
+struct adt7411_data {
+        struct mutex device_lock;       /* for "atomic" device accesses */
+        unsigned long next_update;
+        int vref_cached;
+        bool ref_is_vdd;
+        struct device *hwmon_dev;
+};
+
+/*
+ * When reading a register containing (up to 4) lsb, all associated
+ * msb-registers get locked by the hardware. After _one_ of those msb is read,
+ * _all_ are unlocked. In order to use this locking correctly, reading lsb/msb
+ * is protected here with a mutex, too.
+ */
+static int adt7411_read_10_bit(struct i2c_client *client, u8 lsb_reg,
+                                u8 msb_reg, u8 lsb_shift)
+{
+        struct adt7411_data *data = i2c_get_clientdata(client);
+        int val, tmp;
+
+        mutex_lock(&data->device_lock);
+
+        val = i2c_smbus_read_byte_data(client, lsb_reg);
+        if (val < 0)
+                goto exit_unlock;
+
+        tmp = (val >> lsb_shift) & 3;
+        val = i2c_smbus_read_byte_data(client, msb_reg);
+
+        if (val >= 0)
+                val = (val << 2) | tmp;
+
+ exit_unlock:
+        mutex_unlock(&data->device_lock);
+
+        return val;
+}
+
+static int adt7411_modify_bit(struct i2c_client *client, u8 reg, u8 bit,
+                                bool flag)
+{
+        struct adt7411_data *data = i2c_get_clientdata(client);
+        int ret, val;
+
+        mutex_lock(&data->device_lock);
+
+        ret = i2c_smbus_read_byte_data(client, reg);
+        if (ret < 0)
+                goto exit_unlock;
+
+        if (flag)
+                val = ret | bit;
+        else
+                val = ret & ~bit;
+
+        ret = i2c_smbus_write_byte_data(client, reg, val);
+
+ exit_unlock:
+        mutex_unlock(&data->device_lock);
+        return ret;
+}
+
+static ssize_t adt7411_show_vdd(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        int ret = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
+                        ADT7411_REG_VDD_MSB, 2);
+
+        return ret < 0 ? ret : sprintf(buf, "%u\n", ret * 7000 / 1024);
+}
+
+static ssize_t adt7411_show_temp(struct device *dev,
+                        struct device_attribute *attr, char *buf)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        int val = adt7411_read_10_bit(client, ADT7411_REG_INT_TEMP_VDD_LSB,
+                        ADT7411_REG_INT_TEMP_MSB, 0);
+
+        if (val < 0)
+                return val;
+
+        val = val & 0x200 ? val - 0x400 : val; /* 10 bit signed */
+
+        return sprintf(buf, "%d\n", val * 250);
+}
+
+static ssize_t adt7411_show_input(struct device *dev,
+                                  struct device_attribute *attr, char *buf)
+{
+        int nr = to_sensor_dev_attr(attr)->index;
+        struct i2c_client *client = to_i2c_client(dev);
+        struct adt7411_data *data = i2c_get_clientdata(client);
+        int val;
+        u8 lsb_reg, lsb_shift;
+
+        if (time_after_eq(jiffies, data->next_update)) {
+                val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
+                if (val < 0)
+                        return val;
+                data->ref_is_vdd = val & ADT7411_CFG3_REF_VDD;
+
+                if (data->ref_is_vdd) {
+                        val = adt7411_read_10_bit(client,
+                                        ADT7411_REG_INT_TEMP_VDD_LSB,
+                                        ADT7411_REG_VDD_MSB, 2);
+                        if (val < 0)
+                                return val;
+
+                        data->vref_cached = val * 7000 / 1024;
+                } else {
+                        data->vref_cached = 2250;
+                }
+
+                data->next_update = jiffies + HZ;
+        }
+
+        lsb_reg = ADT7411_REG_EXT_TEMP_AIN14_LSB + (nr >> 2);
+        lsb_shift = 2 * (nr & 0x03);
+        val = adt7411_read_10_bit(client, lsb_reg,
+                        ADT7411_REG_EXT_TEMP_AIN1_MSB + nr, lsb_shift);
+
+        return val < 0 ? val :
+                        sprintf(buf, "%u\n", val * data->vref_cached / 1024);
+}
+
+static ssize_t adt7411_show_bit(struct device *dev,
+                                struct device_attribute *attr, char *buf)
+{
+        struct sensor_device_attribute_2 *attr2 = to_sensor_dev_attr_2(attr);
+        struct i2c_client *client = to_i2c_client(dev);
+        int ret = i2c_smbus_read_byte_data(client, attr2->index);
+
+        return ret < 0 ? ret : sprintf(buf, "%u\n", !!(ret & attr2->nr));
+}
+
+static ssize_t adt7411_set_bit(struct device *dev,
+                               struct device_attribute *attr, const char *buf,
+                               size_t count)
+{
+        struct sensor_device_attribute_2 *s_attr2 = to_sensor_dev_attr_2(attr);
+        struct i2c_client *client = to_i2c_client(dev);
+        struct adt7411_data *data = i2c_get_clientdata(client);
+        int ret;
+        unsigned long flag;
+
+        ret = strict_strtoul(buf, 0, &flag);
+        if (ret || flag > 1)
+                return -EINVAL;
+
+        ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
+
+        /* force update */
+        data->next_update = jiffies;
+
+        return ret < 0 ? ret : count;
+}
+
+#define ADT7411_BIT_ATTR(__name, __reg, __bit) \
+        SENSOR_DEVICE_ATTR_2(__name, S_IRUGO | S_IWUSR, adt7411_show_bit, \
+        adt7411_set_bit, __bit, __reg)
+
+static DEVICE_ATTR(temp1_input, S_IRUGO, adt7411_show_temp, NULL);
+static DEVICE_ATTR(in0_input, S_IRUGO, adt7411_show_vdd, NULL);
+static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, adt7411_show_input, NULL, 0);
+static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, adt7411_show_input, NULL, 1);
+static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, adt7411_show_input, NULL, 2);
+static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, adt7411_show_input, NULL, 3);
+static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, adt7411_show_input, NULL, 4);
+static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, adt7411_show_input, NULL, 5);
+static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, adt7411_show_input, NULL, 6);
+static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, adt7411_show_input, NULL, 7);
+static ADT7411_BIT_ATTR(no_average, ADT7411_REG_CFG2, ADT7411_CFG2_DISABLE_AVG);
+static ADT7411_BIT_ATTR(fast_sampling, ADT7411_REG_CFG3, ADT7411_CFG3_ADC_CLK_225);
+static ADT7411_BIT_ATTR(adc_ref_vdd, ADT7411_REG_CFG3, ADT7411_CFG3_REF_VDD);
+
+static struct attribute *adt7411_attrs[] = {
+        &dev_attr_temp1_input.attr,
+        &dev_attr_in0_input.attr,
+        &sensor_dev_attr_in1_input.dev_attr.attr,
+        &sensor_dev_attr_in2_input.dev_attr.attr,
+        &sensor_dev_attr_in3_input.dev_attr.attr,
+        &sensor_dev_attr_in4_input.dev_attr.attr,
+        &sensor_dev_attr_in5_input.dev_attr.attr,
+        &sensor_dev_attr_in6_input.dev_attr.attr,
+        &sensor_dev_attr_in7_input.dev_attr.attr,
+        &sensor_dev_attr_in8_input.dev_attr.attr,
+        &sensor_dev_attr_no_average.dev_attr.attr,
+        &sensor_dev_attr_fast_sampling.dev_attr.attr,
+        &sensor_dev_attr_adc_ref_vdd.dev_attr.attr,
+        NULL
+};
+
+static const struct attribute_group adt7411_attr_grp = {
+        .attrs = adt7411_attrs,
+};
+
+static int adt7411_detect(struct i2c_client *client,
+                          struct i2c_board_info *info)
+{
+        int val;
+
+        if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+                return -ENODEV;
+
+        val = i2c_smbus_read_byte_data(client, ADT7411_REG_MANUFACTURER_ID);
+        if (val < 0 || val != ADT7411_MANUFACTURER_ID) {
+                dev_dbg(&client->dev, "Wrong manufacturer ID. Got %d, "
+                        "expected %d\n", val, ADT7411_MANUFACTURER_ID);
+                return -ENODEV;
+        }
+
+        val = i2c_smbus_read_byte_data(client, ADT7411_REG_DEVICE_ID);
+        if (val < 0 || val != ADT7411_DEVICE_ID) {
+                dev_dbg(&client->dev, "Wrong device ID. Got %d, "
+                        "expected %d\n", val, ADT7411_DEVICE_ID);
+                return -ENODEV;
+        }
+
+        strlcpy(info->type, "adt7411", I2C_NAME_SIZE);
+
+        return 0;
+}
+
+static int __devinit adt7411_probe(struct i2c_client *client,
+                                   const struct i2c_device_id *id)
+{
+        struct adt7411_data *data;
+        int ret;
+
+        data = kzalloc(sizeof(*data), GFP_KERNEL);
+        if (!data)
+                return -ENOMEM;
+
+        i2c_set_clientdata(client, data);
+        mutex_init(&data->device_lock);
+
+        ret = adt7411_modify_bit(client, ADT7411_REG_CFG1,
+                                 ADT7411_CFG1_START_MONITOR, 1);
+        if (ret < 0)
+                goto exit_free;
+
+        /* force update on first occasion */
+        data->next_update = jiffies;
+
+        ret = sysfs_create_group(&client->dev.kobj, &adt7411_attr_grp);
+        if (ret)
+                goto exit_free;
+
+        data->hwmon_dev = hwmon_device_register(&client->dev);
+        if (IS_ERR(data->hwmon_dev)) {
+                ret = PTR_ERR(data->hwmon_dev);
+                goto exit_remove;
+        }
+
+        dev_info(&client->dev, "successfully registered\n");
+
+        return 0;
+
+ exit_remove:
+        sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp);
+ exit_free:
+        i2c_set_clientdata(client, NULL);
+        kfree(data);
+        return ret;
+}
+
+static int __devexit adt7411_remove(struct i2c_client *client)
+{
+        struct adt7411_data *data = i2c_get_clientdata(client);
+
+        hwmon_device_unregister(data->hwmon_dev);
+        sysfs_remove_group(&client->dev.kobj, &adt7411_attr_grp);
+        i2c_set_clientdata(client, NULL);
+        kfree(data);
+        return 0;
+}
+
+static const struct i2c_device_id adt7411_id[] = {
+        { "adt7411", 0 },
+        { }
+};
+
+static struct i2c_driver adt7411_driver = {
+        .driver         = {
+                .name           = "adt7411",
+        },
+        .probe  = adt7411_probe,
+        .remove = __devexit_p(adt7411_remove),
+        .id_table = adt7411_id,
+        .detect = adt7411_detect,
+        .address_list = normal_i2c,
+        .class = I2C_CLASS_HWMON,
+};
+
+static int __init sensors_adt7411_init(void)
+{
+        return i2c_add_driver(&adt7411_driver);
+}
+module_init(sensors_adt7411_init)
+
+static void __exit sensors_adt7411_exit(void)
+{
+        i2c_del_driver(&adt7411_driver);
+}
+module_exit(sensors_adt7411_exit)
+
+MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de> and "
+        "Wolfram Sang <w.sang@pengutronix.de>");
+MODULE_DESCRIPTION("ADT7411 driver");
+MODULE_LICENSE("GPL v2");