hwmon: add support for JEDEC JC 42.4 compliant temperature sensors

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: Randy Dunlap <rdunlap@xenotime.net>
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 593 insertions, 0 deletions

diff --git a/drivers/hwmon/jc42.c b/drivers/hwmon/jc42.c
new file mode 100644
index 000000000000..340fc78c8dde
--- /dev/null
+++ b/drivers/hwmon/jc42.c
@@ -0,0 +1,593 @@
+/*
+ * jc42.c - driver for Jedec JC42.4 compliant temperature sensors
+ *
+ * Copyright (c) 2010  Ericsson AB.
+ *
+ * Derived from lm77.c by Andras BALI <drewie@freemail.hu>.
+ *
+ * JC42.4 compliant temperature sensors are typically used on memory modules.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/jiffies.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+
+/* Addresses to scan */
+static const unsigned short normal_i2c[] = {
+        0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };
+
+/* JC42 registers. All registers are 16 bit. */
+#define JC42_REG_CAP            0x00
+#define JC42_REG_CONFIG         0x01
+#define JC42_REG_TEMP_UPPER     0x02
+#define JC42_REG_TEMP_LOWER     0x03
+#define JC42_REG_TEMP_CRITICAL  0x04
+#define JC42_REG_TEMP           0x05
+#define JC42_REG_MANID          0x06
+#define JC42_REG_DEVICEID       0x07
+
+/* Status bits in temperature register */
+#define JC42_ALARM_CRIT_BIT     15
+#define JC42_ALARM_MAX_BIT      14
+#define JC42_ALARM_MIN_BIT      13
+
+/* Configuration register defines */
+#define JC42_CFG_CRIT_ONLY      (1 << 2)
+#define JC42_CFG_SHUTDOWN       (1 << 8)
+#define JC42_CFG_HYST_SHIFT     9
+#define JC42_CFG_HYST_MASK      0x03
+
+/* Capabilities */
+#define JC42_CAP_RANGE          (1 << 2)
+
+/* Manufacturer IDs */
+#define ADT_MANID               0x11d4  /* Analog Devices */
+#define MAX_MANID               0x004d  /* Maxim */
+#define IDT_MANID               0x00b3  /* IDT */
+#define MCP_MANID               0x0054  /* Microchip */
+#define NXP_MANID               0x1131  /* NXP Semiconductors */
+#define ONS_MANID               0x1b09  /* ON Semiconductor */
+#define STM_MANID               0x104a  /* ST Microelectronics */
+
+/* Supported chips */
+
+/* Analog Devices */
+#define ADT7408_DEVID           0x0801
+#define ADT7408_DEVID_MASK      0xffff
+
+/* IDT */
+#define TS3000B3_DEVID          0x2903  /* Also matches TSE2002B3 */
+#define TS3000B3_DEVID_MASK     0xffff
+
+/* Maxim */
+#define MAX6604_DEVID           0x3e00
+#define MAX6604_DEVID_MASK      0xffff
+
+/* Microchip */
+#define MCP98242_DEVID          0x2000
+#define MCP98242_DEVID_MASK     0xfffc
+
+#define MCP98243_DEVID          0x2100
+#define MCP98243_DEVID_MASK     0xfffc
+
+#define MCP9843_DEVID           0x0000  /* Also matches mcp9805 */
+#define MCP9843_DEVID_MASK      0xfffe
+
+/* NXP */
+#define SE97_DEVID              0xa200
+#define SE97_DEVID_MASK         0xfffc
+
+#define SE98_DEVID              0xa100
+#define SE98_DEVID_MASK         0xfffc
+
+/* ON Semiconductor */
+#define CAT6095_DEVID           0x0800  /* Also matches CAT34TS02 */
+#define CAT6095_DEVID_MASK      0xffe0
+
+/* ST Microelectronics */
+#define STTS424_DEVID           0x0101
+#define STTS424_DEVID_MASK      0xffff
+
+#define STTS424E_DEVID          0x0000
+#define STTS424E_DEVID_MASK     0xfffe
+
+static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
+
+struct jc42_chips {
+        u16 manid;
+        u16 devid;
+        u16 devid_mask;
+};
+
+static struct jc42_chips jc42_chips[] = {
+        { ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
+        { IDT_MANID, TS3000B3_DEVID, TS3000B3_DEVID_MASK },
+        { MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
+        { MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
+        { MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
+        { MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
+        { NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
+        { ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
+        { NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
+        { STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
+        { STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
+};
+
+/* Each client has this additional data */
+struct jc42_data {
+        struct device   *hwmon_dev;
+        struct mutex    update_lock;    /* protect register access */
+        bool            extended;       /* true if extended range supported */
+        bool            valid;
+        unsigned long   last_updated;   /* In jiffies */
+        u16             orig_config;    /* original configuration */
+        u16             config;         /* current configuration */
+        u16             temp_input;     /* Temperatures */
+        u16             temp_crit;
+        u16             temp_min;
+        u16             temp_max;
+};
+
+static int jc42_probe(struct i2c_client *client,
+                      const struct i2c_device_id *id);
+static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info);
+static int jc42_remove(struct i2c_client *client);
+static int jc42_read_value(struct i2c_client *client, u8 reg);
+static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value);
+
+static struct jc42_data *jc42_update_device(struct device *dev);
+
+static const struct i2c_device_id jc42_id[] = {
+        { "adt7408", 0 },
+        { "cat94ts02", 0 },
+        { "cat6095", 0 },
+        { "jc42", 0 },
+        { "max6604", 0 },
+        { "mcp9805", 0 },
+        { "mcp98242", 0 },
+        { "mcp98243", 0 },
+        { "mcp9843", 0 },
+        { "se97", 0 },
+        { "se97b", 0 },
+        { "se98", 0 },
+        { "stts424", 0 },
+        { "tse2002b3", 0 },
+        { "ts3000b3", 0 },
+        { }
+};
+MODULE_DEVICE_TABLE(i2c, jc42_id);
+
+#ifdef CONFIG_PM
+
+static int jc42_suspend(struct device *dev)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        struct jc42_data *data = i2c_get_clientdata(client);
+
+        data->config |= JC42_CFG_SHUTDOWN;
+        jc42_write_value(client, JC42_REG_CONFIG, data->config);
+        return 0;
+}
+
+static int jc42_resume(struct device *dev)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        struct jc42_data *data = i2c_get_clientdata(client);
+
+        data->config &= ~JC42_CFG_SHUTDOWN;
+        jc42_write_value(client, JC42_REG_CONFIG, data->config);
+        return 0;
+}
+
+static const struct dev_pm_ops jc42_dev_pm_ops = {
+        .suspend = jc42_suspend,
+        .resume = jc42_resume,
+};
+
+#define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
+#else
+#define JC42_DEV_PM_OPS NULL
+#endif /* CONFIG_PM */
+
+/* This is the driver that will be inserted */
+static struct i2c_driver jc42_driver = {
+        .class          = I2C_CLASS_HWMON,
+        .driver = {
+                .name   = "jc42",
+                .pm = JC42_DEV_PM_OPS,
+        },
+        .probe          = jc42_probe,
+        .remove         = jc42_remove,
+        .id_table       = jc42_id,
+        .detect         = jc42_detect,
+        .address_list   = normal_i2c,
+};
+
+#define JC42_TEMP_MIN_EXTENDED  (-40000)
+#define JC42_TEMP_MIN           0
+#define JC42_TEMP_MAX           125000
+
+static u16 jc42_temp_to_reg(int temp, bool extended)
+{
+        int ntemp = SENSORS_LIMIT(temp,
+                                  extended ? JC42_TEMP_MIN_EXTENDED :
+                                  JC42_TEMP_MIN, JC42_TEMP_MAX);
+
+        /* convert from 0.001 to 0.0625 resolution */
+        return (ntemp * 2 / 125) & 0x1fff;
+}
+
+static int jc42_temp_from_reg(s16 reg)
+{
+        reg &= 0x1fff;
+
+        /* sign extend register */
+        if (reg & 0x1000)
+                reg |= 0xf000;
+
+        /* convert from 0.0625 to 0.001 resolution */
+        return reg * 125 / 2;
+}
+
+/* sysfs stuff */
+
+/* read routines for temperature limits */
+#define show(value)     \
+static ssize_t show_##value(struct device *dev,                         \
+                            struct device_attribute *attr,              \
+                            char *buf)                                  \
+{                                                                       \
+        struct jc42_data *data = jc42_update_device(dev);               \
+        if (IS_ERR(data))                                               \
+                return PTR_ERR(data);                                   \
+        return sprintf(buf, "%d\n", jc42_temp_from_reg(data->value));   \
+}
+
+show(temp_input);
+show(temp_crit);
+show(temp_min);
+show(temp_max);
+
+/* read routines for hysteresis values */
+static ssize_t show_temp_crit_hyst(struct device *dev,
+                                   struct device_attribute *attr, char *buf)
+{
+        struct jc42_data *data = jc42_update_device(dev);
+        int temp, hyst;
+
+        if (IS_ERR(data))
+                return PTR_ERR(data);
+
+        temp = jc42_temp_from_reg(data->temp_crit);
+        hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
+                               & JC42_CFG_HYST_MASK];
+        return sprintf(buf, "%d\n", temp - hyst);
+}
+
+static ssize_t show_temp_max_hyst(struct device *dev,
+                                  struct device_attribute *attr, char *buf)
+{
+        struct jc42_data *data = jc42_update_device(dev);
+        int temp, hyst;
+
+        if (IS_ERR(data))
+                return PTR_ERR(data);
+
+        temp = jc42_temp_from_reg(data->temp_max);
+        hyst = jc42_hysteresis[(data->config >> JC42_CFG_HYST_SHIFT)
+                               & JC42_CFG_HYST_MASK];
+        return sprintf(buf, "%d\n", temp - hyst);
+}
+
+/* write routines */
+#define set(value, reg) \
+static ssize_t set_##value(struct device *dev,                          \
+                           struct device_attribute *attr,               \
+                           const char *buf, size_t count)               \
+{                                                                       \
+        struct i2c_client *client = to_i2c_client(dev);                 \
+        struct jc42_data *data = i2c_get_clientdata(client);            \
+        int err, ret = count;                                           \
+        long val;                                                       \
+        if (strict_strtol(buf, 10, &val) < 0)                           \
+                return -EINVAL;                                         \
+        mutex_lock(&data->update_lock);                                 \
+        data->value = jc42_temp_to_reg(val, data->extended);            \
+        err = jc42_write_value(client, reg, data->value);               \
+        if (err < 0)                                                    \
+                ret = err;                                              \
+        mutex_unlock(&data->update_lock);                               \
+        return ret;                                                     \
+}
+
+set(temp_min, JC42_REG_TEMP_LOWER);
+set(temp_max, JC42_REG_TEMP_UPPER);
+set(temp_crit, JC42_REG_TEMP_CRITICAL);
+
+/* JC42.4 compliant chips only support four hysteresis values.
+ * Pick best choice and go from there. */
+static ssize_t set_temp_crit_hyst(struct device *dev,
+                                  struct device_attribute *attr,
+                                  const char *buf, size_t count)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        struct jc42_data *data = i2c_get_clientdata(client);
+        long val;
+        int diff, hyst;
+        int err;
+        int ret = count;
+
+        if (strict_strtoul(buf, 10, &val) < 0)
+                return -EINVAL;
+
+        diff = jc42_temp_from_reg(data->temp_crit) - val;
+        hyst = 0;
+        if (diff > 0) {
+                if (diff < 2250)
+                        hyst = 1;       /* 1.5 degrees C */
+                else if (diff < 4500)
+                        hyst = 2;       /* 3.0 degrees C */
+                else
+                        hyst = 3;       /* 6.0 degrees C */
+        }
+
+        mutex_lock(&data->update_lock);
+        data->config = (data->config
+                        & ~(JC42_CFG_HYST_MASK << JC42_CFG_HYST_SHIFT))
+          | (hyst << JC42_CFG_HYST_SHIFT);
+        err = jc42_write_value(client, JC42_REG_CONFIG, data->config);
+        if (err < 0)
+                ret = err;
+        mutex_unlock(&data->update_lock);
+        return ret;
+}
+
+static ssize_t show_alarm(struct device *dev,
+                          struct device_attribute *attr, char *buf)
+{
+        u16 bit = to_sensor_dev_attr(attr)->index;
+        struct jc42_data *data = jc42_update_device(dev);
+        u16 val;
+
+        if (IS_ERR(data))
+                return PTR_ERR(data);
+
+        val = data->temp_input;
+        if (bit != JC42_ALARM_CRIT_BIT && (data->config & JC42_CFG_CRIT_ONLY))
+                val = 0;
+        return sprintf(buf, "%u\n", (val >> bit) & 1);
+}
+
+static DEVICE_ATTR(temp1_input, S_IRUGO,
+                   show_temp_input, NULL);
+static DEVICE_ATTR(temp1_crit, S_IWUSR | S_IRUGO,
+                   show_temp_crit, set_temp_crit);
+static DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO,
+                   show_temp_min, set_temp_min);
+static DEVICE_ATTR(temp1_max, S_IWUSR | S_IRUGO,
+                   show_temp_max, set_temp_max);
+
+static DEVICE_ATTR(temp1_crit_hyst, S_IWUSR | S_IRUGO,
+                   show_temp_crit_hyst, set_temp_crit_hyst);
+static DEVICE_ATTR(temp1_max_hyst, S_IRUGO,
+                   show_temp_max_hyst, NULL);
+
+static SENSOR_DEVICE_ATTR(temp1_crit_alarm, S_IRUGO, show_alarm, NULL,
+                          JC42_ALARM_CRIT_BIT);
+static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, show_alarm, NULL,
+                          JC42_ALARM_MIN_BIT);
+static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, show_alarm, NULL,
+                          JC42_ALARM_MAX_BIT);
+
+static struct attribute *jc42_attributes[] = {
+        &dev_attr_temp1_input.attr,
+        &dev_attr_temp1_crit.attr,
+        &dev_attr_temp1_min.attr,
+        &dev_attr_temp1_max.attr,
+        &dev_attr_temp1_crit_hyst.attr,
+        &dev_attr_temp1_max_hyst.attr,
+        &sensor_dev_attr_temp1_crit_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp1_min_alarm.dev_attr.attr,
+        &sensor_dev_attr_temp1_max_alarm.dev_attr.attr,
+        NULL
+};
+
+static const struct attribute_group jc42_group = {
+        .attrs = jc42_attributes,
+};
+
+/* Return 0 if detection is successful, -ENODEV otherwise */
+static int jc42_detect(struct i2c_client *new_client,
+                       struct i2c_board_info *info)
+{
+        struct i2c_adapter *adapter = new_client->adapter;
+        int i, config, cap, manid, devid;
+
+        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
+                                     I2C_FUNC_SMBUS_WORD_DATA))
+                return -ENODEV;
+
+        cap = jc42_read_value(new_client, JC42_REG_CAP);
+        config = jc42_read_value(new_client, JC42_REG_CONFIG);
+        manid = jc42_read_value(new_client, JC42_REG_MANID);
+        devid = jc42_read_value(new_client, JC42_REG_DEVICEID);
+
+        if (cap < 0 || config < 0 || manid < 0 || devid < 0)
+                return -ENODEV;
+
+        if ((cap & 0xff00) || (config & 0xf800))
+                return -ENODEV;
+
+        for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
+                struct jc42_chips *chip = &jc42_chips[i];
+                if (manid == chip->manid &&
+                    (devid & chip->devid_mask) == chip->devid) {
+                        strlcpy(info->type, "jc42", I2C_NAME_SIZE);
+                        return 0;
+                }
+        }
+        return -ENODEV;
+}
+
+static int jc42_probe(struct i2c_client *new_client,
+                      const struct i2c_device_id *id)
+{
+        struct jc42_data *data;
+        int config, cap, err;
+
+        data = kzalloc(sizeof(struct jc42_data), GFP_KERNEL);
+        if (!data) {
+                err = -ENOMEM;
+                goto exit;
+        }
+
+        i2c_set_clientdata(new_client, data);
+        mutex_init(&data->update_lock);
+
+        cap = jc42_read_value(new_client, JC42_REG_CAP);
+        if (cap < 0) {
+                err = -EINVAL;
+                goto exit_free;
+        }
+        data->extended = !!(cap & JC42_CAP_RANGE);
+
+        config = jc42_read_value(new_client, JC42_REG_CONFIG);
+        if (config < 0) {
+                err = -EINVAL;
+                goto exit_free;
+        }
+        data->orig_config = config;
+        if (config & JC42_CFG_SHUTDOWN) {
+                config &= ~JC42_CFG_SHUTDOWN;
+                jc42_write_value(new_client, JC42_REG_CONFIG, config);
+        }
+        data->config = config;
+
+        /* Register sysfs hooks */
+        err = sysfs_create_group(&new_client->dev.kobj, &jc42_group);
+        if (err)
+                goto exit_free;
+
+        data->hwmon_dev = hwmon_device_register(&new_client->dev);
+        if (IS_ERR(data->hwmon_dev)) {
+                err = PTR_ERR(data->hwmon_dev);
+                goto exit_remove;
+        }
+
+        return 0;
+
+exit_remove:
+        sysfs_remove_group(&new_client->dev.kobj, &jc42_group);
+exit_free:
+        kfree(data);
+exit:
+        return err;
+}
+
+static int jc42_remove(struct i2c_client *client)
+{
+        struct jc42_data *data = i2c_get_clientdata(client);
+        hwmon_device_unregister(data->hwmon_dev);
+        sysfs_remove_group(&client->dev.kobj, &jc42_group);
+        if (data->config != data->orig_config)
+                jc42_write_value(client, JC42_REG_CONFIG, data->orig_config);
+        kfree(data);
+        return 0;
+}
+
+/* All registers are word-sized. */
+static int jc42_read_value(struct i2c_client *client, u8 reg)
+{
+        int ret = i2c_smbus_read_word_data(client, reg);
+        if (ret < 0)
+                return ret;
+        return swab16(ret);
+}
+
+static int jc42_write_value(struct i2c_client *client, u8 reg, u16 value)
+{
+        return i2c_smbus_write_word_data(client, reg, swab16(value));
+}
+
+static struct jc42_data *jc42_update_device(struct device *dev)
+{
+        struct i2c_client *client = to_i2c_client(dev);
+        struct jc42_data *data = i2c_get_clientdata(client);
+        struct jc42_data *ret = data;
+        int val;
+
+        mutex_lock(&data->update_lock);
+
+        if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
+                val = jc42_read_value(client, JC42_REG_TEMP);
+                if (val < 0) {
+                        ret = ERR_PTR(val);
+                        goto abort;
+                }
+                data->temp_input = val;
+
+                val = jc42_read_value(client, JC42_REG_TEMP_CRITICAL);
+                if (val < 0) {
+                        ret = ERR_PTR(val);
+                        goto abort;
+                }
+                data->temp_crit = val;
+
+                val = jc42_read_value(client, JC42_REG_TEMP_LOWER);
+                if (val < 0) {
+                        ret = ERR_PTR(val);
+                        goto abort;
+                }
+                data->temp_min = val;
+
+                val = jc42_read_value(client, JC42_REG_TEMP_UPPER);
+                if (val < 0) {
+                        ret = ERR_PTR(val);
+                        goto abort;
+                }
+                data->temp_max = val;
+
+                data->last_updated = jiffies;
+                data->valid = true;
+        }
+abort:
+        mutex_unlock(&data->update_lock);
+        return ret;
+}
+
+static int __init sensors_jc42_init(void)
+{
+        return i2c_add_driver(&jc42_driver);
+}
+
+static void __exit sensors_jc42_exit(void)
+{
+        i2c_del_driver(&jc42_driver);
+}
+
+MODULE_AUTHOR("Guenter Roeck <guenter.roeck@ericsson.com>");
+MODULE_DESCRIPTION("JC42 driver");
+MODULE_LICENSE("GPL");
+
+module_init(sensors_jc42_init);
+module_exit(sensors_jc42_exit);