On Sat, Dec 29, 2012 at 12:56 AM, Chris Verges <kg4ysn@xxxxxxxxx> wrote: > *snip* I was able to test the 'update_interval' attribute fully, but was only able to partially test the alarm-related attributes. If anyone else has an lm73 with access to the ALERT pin and can do live testing, feedback would be outstanding. Thanks, Chris > The LM73 supports four A/D conversion resolutions. The default used by > the existing lm73 driver is the chip's default, 11-bit (0.25 C/LSB). > This patch enables changing of this resolution from userspace via the > temp1_update_interval attribute. > > The LM73 also supports a basic over-temperature indicator. When the > measured temperature goes above the high temperature limit, temp1_max, > the alarm is triggered. When it drops below the low temperature limit, > temp1_min, the alarm is ended. > > Full details on use of these mechanisms are described in > Documentation/hwmon/lm73. > > Signed-off-by: Chris Verges <kg4ysn@xxxxxxxxx> > --- > Documentation/hwmon/lm73 | 108 +++++++++++++++ > drivers/hwmon/lm73.c | 263 +++++++++++++++++++++++++++++++++++- > include/linux/platform_data/lm73.h | 38 ++++++ > 3 files changed, 405 insertions(+), 4 deletions(-) > create mode 100644 Documentation/hwmon/lm73 > create mode 100644 include/linux/platform_data/lm73.h > > diff --git a/Documentation/hwmon/lm73 b/Documentation/hwmon/lm73 > new file mode 100644 > index 0000000..24dfd8a > --- /dev/null > +++ b/Documentation/hwmon/lm73 > @@ -0,0 +1,108 @@ > +Kernel driver lm73 > +================== > + > +Supported chips: > + * Texas Instruments LM73 > + Prefix: 'lm73' > + Addresses scanned: I2C 0x48, 0x49, 0x4a, 0x4c, 0x4d, and 0x4e > + Datasheet: Publicly available at the Texas Instruments website > + http://www.ti.com/product/lm73 > + > +Author: Chris Verges <kg4ysn@xxxxxxxxx> > + > + > +Description > +----------- > + > +The LM73 is a digital temperature sensor. All temperature values are > +given in degrees Celsius. > + > +Measurement Resolution Support > +------------------------------ > + > +The LM73 supports four resolutions, defined in terms of degrees C per > +LSB: 0.25, 0.125, 0.0625, and 0.3125. Changing the resolution mode > +affects the conversion time of the LM73's analog-to-digital converter. > +From userspace, the desired resolution can be specified as a function of > +conversion time via the 'update_interval' sysfs attribute for the > +device. This attribute will normalize ranges of input values to the > +maximum times defined for the resolution in the datasheet. > + > + Resolution Conv. Time Input Range > + (C/LSB) (msec) (msec) > + -------------------------------------- > + 0.25 14 0..21 > + 0.125 28 22..42 > + 0.0625 56 43..84 > + 0.03125 112 85..infinity > + -------------------------------------- > + > +The following examples show how the 'update_interval' attribute can be > +used to change the conversion time: > + > + $ echo 0 > temp1_update_interval > + $ cat temp1_update_interval > + 14 > + $ cat temp1_input > + 24250 > + > + $ echo 36 > temp1_update_interval > + $ cat temp1_update_interval > + 28 > + $ cat temp1_input > + 24125 > + > + $ echo 56 > temp1_update_interval > + $ cat temp1_update_interval > + 56 > + $ cat temp1_input > + 24062 > + > + $ echo 85 > temp1_update_interval > + $ cat temp1_update_interval > + 112 > + $ cat temp1_input > + 24031 > + > +As shown here, the lm73 driver automatically adjusts any user input for > +'update_interval' via a step function. Reading back the > +'update_interval' value after a write operation will confirm the > +conversion time actively in use. > + > +Mathematically, the resolution can be derived from the conversion time > +via the following function: > + > + g(x) = 0.250 * [log(x/14) / log(2)] > + > +where 'x' is the output from 'update_interval' and 'g(x)' is the > +resolution in degrees C per LSB. > + > +Alarm Support > +------------- > + > +The LM73 features a simple over-temperature alarm mechanism. This > +feature is exposed via the sysfs attributes and (optionally) via > +platform device interrupt handling hooks. > + > +The primary attribute is 'temp1_alarm.' When the measured temperature > +exceeds the value stored in 'temp1_max', the alarm triggers. When the > +measured temperature drops below the value stored in 'temp1_min', the > +alarm is cleared. The alarm can also be cleared by writing a '0' to the > +'temp1_alarm' attribute. > + > +The attributes 'temp1_max_alarm' and 'temp1_min_alarm' are flags > +provided by the LM73 that indicate whether the measured temperature has > +passed the 'temp1_max' and 'temp1_min' thresholds, respectively. These > +values _must_ be read to clear the registers on the LM73. > + > +If the lm73 driver is provided a struct lm73_platform_data during > +initialization, interrupt handling is enabled. The platform must define > +the IRQ number and IRQ flags at a minimum, and can optionally also > +define a callback function to supplement the IRQ handler provided by the > +lm73 driver. This internal IRQ handler enables use of epoll() on the > +'temp1_alarm' attribute via the sysfs_notify() method. > + > +Finally, the LM73 can set the polarity of the ALERT interrupt to either > +active-high or active-low (default). If the platform desired the > +polarity to be switched to active-high, it can declare this in the > +struct lm73_platform_data used during initialization. > diff --git a/drivers/hwmon/lm73.c b/drivers/hwmon/lm73.c > index 7272176..4acb0e2 100644 > --- a/drivers/hwmon/lm73.c > +++ b/drivers/hwmon/lm73.c > @@ -20,7 +20,8 @@ > #include <linux/hwmon.h> > #include <linux/hwmon-sysfs.h> > #include <linux/err.h> > - > +#include <linux/interrupt.h> > +#include <linux/platform_data/lm73.h> > > /* Addresses scanned */ > static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4c, > @@ -39,8 +40,91 @@ static const unsigned short normal_i2c[] = { 0x48, 0x49, 0x4a, 0x4c, > #define LM73_TEMP_MIN (-40) > #define LM73_TEMP_MAX 150 > > +#define LM73_CTRL_RES_SHIFT 5 > +#define LM73_CTRL_RES_SIZE 2 > +#define LM73_CTRL_RES_MASK \ > + (((1 << LM73_CTRL_RES_SIZE) - 1) << LM73_CTRL_RES_SHIFT) > + > +#define LM73_CTRL_ALERT_SHIFT 3 > +#define LM73_CTRL_ALERT_SIZE 1 > +#define LM73_CTRL_ALERT_MASK \ > + (((1 << LM73_CTRL_ALERT_SIZE) - 1) << LM73_CTRL_ALERT_SHIFT) > + > +#define LM73_CTRL_HI_SHIFT 2 > +#define LM73_CTRL_HI_SIZE 1 > +#define LM73_CTRL_HI_MASK \ > + (((1 << LM73_CTRL_HI_SIZE) - 1) << LM73_CTRL_HI_SHIFT) > + > +#define LM73_CTRL_LO_SHIFT 1 > +#define LM73_CTRL_LO_SIZE 1 > +#define LM73_CTRL_LO_MASK \ > + (((1 << LM73_CTRL_LO_SIZE) - 1) << LM73_CTRL_LO_SHIFT) > + > +#define LM73_CTRL_HILO_MASK \ > + (LM73_CTRL_HI_MASK | LM73_CTRL_LO_MASK) > + > +#define LM73_CONF_POL_SHIFT 4 > +#define LM73_CONF_POL_SIZE 1 > +#define LM73_CONF_POL_MASK \ > + (((1 << LM73_CONF_POL_SIZE) - 1) << LM73_CONF_POL_SHIFT) > + > +#define LM73_CONF_RESET_SHIFT 3 > +#define LM73_CONF_RESET_SIZE 1 > +#define LM73_CONF_RESET_MASK \ > + (((1 << LM73_CONF_RESET_SIZE) - 1) << LM73_CONF_RESET_SHIFT) > + > +#define SCALE_150_PERCENT(x) ((x) + (x)/2) > + > +static const unsigned short lm73_valid_convrates[] = { > + 14, /* 11-bits (0.25000 C/LSB): RES1 Bit = 0, RES0 Bit = 0 */ > + 28, /* 12-bits (0.12500 C/LSB): RES1 Bit = 0, RES0 Bit = 1 */ > + 56, /* 13-bits (0.06250 C/LSB): RES1 Bit = 1, RES0 Bit = 0 */ > + 112, /* 14-bits (0.03125 C/LSB): RES1 Bit = 1, RES0 Bit = 1 */ > +}; > + > /*-----------------------------------------------------------------------*/ > > +/* utility functions */ > + > +static inline s32 lm73_read(struct i2c_client *client, u8 reg) > +{ > + return i2c_smbus_read_byte_data(client, reg); > +} > + > +static inline s32 lm73_write(struct i2c_client *client, u8 reg, > + u8 clear, u8 enable) > +{ > + s32 tmp = lm73_read(client, reg); > + u8 value; > + if (tmp < 0) > + return tmp; > + value = tmp; > + value &= ~clear; > + value |= enable; > + return i2c_smbus_write_byte_data(client, reg, value); > +} > + > +static inline s32 lm73_write_conf(struct i2c_client *client, u8 clear, > + u8 enable) > +{ > + /* always clear bits 1:0 and set bit 6 */ > + enable &= ~(3 << 0); > + return lm73_write(client, LM73_REG_CONF, > + clear | (3 << 0), > + enable | (1 << 6)); > +} > + > +static inline s32 lm73_write_ctrl(struct i2c_client *client, u8 clear, > + u8 enable) > +{ > + /* always clear bits 4:3 and 0 */ > + enable &= ~((3 << 3) | (1 << 0)); > + return lm73_write(client, LM73_REG_CTRL, > + clear | (3 << 3) | (1 << 0), > + enable); > +} > + > +/*-----------------------------------------------------------------------*/ > > static ssize_t set_temp(struct device *dev, struct device_attribute *da, > const char *buf, size_t count) > @@ -59,7 +143,9 @@ static ssize_t set_temp(struct device *dev, struct device_attribute *da, > value = (short) SENSORS_LIMIT(temp/250, (LM73_TEMP_MIN*4), > (LM73_TEMP_MAX*4)) << 5; > err = i2c_smbus_write_word_swapped(client, attr->index, value); > - return (err < 0) ? err : count; > + if (err < 0) > + return err; > + return count; > } > > static ssize_t show_temp(struct device *dev, struct device_attribute *da, > @@ -79,6 +165,121 @@ static ssize_t show_temp(struct device *dev, struct device_attribute *da, > return scnprintf(buf, PAGE_SIZE, "%d\n", temp); > } > > +static ssize_t set_convrate(struct device *dev, struct device_attribute *da, > + const char *buf, size_t count) > +{ > + struct i2c_client *client = to_i2c_client(dev); > + unsigned long convrate; > + s32 err; > + u8 res_bits = 0; > + > + err = kstrtoul(buf, 10, &convrate); > + if (err < 0) > + return err; > + > + /* Convert the desired conversion rate into register bits */ > + if (convrate < SCALE_150_PERCENT(lm73_valid_convrates[0])) > + res_bits = 0; > + else if (convrate < SCALE_150_PERCENT(lm73_valid_convrates[1])) > + res_bits = 1; > + else if (convrate < SCALE_150_PERCENT(lm73_valid_convrates[2])) > + res_bits = 2; > + else > + res_bits = 3; > + > + err = lm73_write_ctrl(client, LM73_CTRL_RES_MASK, > + res_bits << LM73_CTRL_RES_SHIFT); > + if (err < 0) > + return err; > + > + return count; > +} > + > +static ssize_t show_convrate(struct device *dev, struct device_attribute *da, > + char *buf) > +{ > + struct i2c_client *client = to_i2c_client(dev); > + s32 ctrl; > + u8 res_bits = 0; > + > + /* Read existing control value */ > + ctrl = lm73_read(client, LM73_REG_CTRL); > + if (ctrl < 0) > + return ctrl; > + > + res_bits = (ctrl & LM73_CTRL_RES_MASK) >> LM73_CTRL_RES_SHIFT; > + return scnprintf(buf, PAGE_SIZE, "%hu\n", > + lm73_valid_convrates[res_bits]); > +} > + > +static ssize_t reset_alarm(struct device *dev, struct device_attribute *da, > + const char *buf, size_t count) > +{ > + struct i2c_client *client = to_i2c_client(dev); > + unsigned long input; > + s32 err; > + > + err = kstrtoul(buf, 10, &input); > + if (err < 0) > + return err; > + > + /* ignore everything but a reset request */ > + if (input) > + return -EINVAL; > + > + err = lm73_write_conf(client, 0, LM73_CONF_RESET_MASK); > + if (err < 0) > + return err; > + return count; > +} > + > +static ssize_t show_alarm(struct device *dev, struct device_attribute *da, > + char *buf) > +{ > + struct i2c_client *client = to_i2c_client(dev); > + s32 ctrl; > + s32 conf; > + > + ctrl = lm73_read(client, LM73_REG_CTRL); > + if (ctrl < 0) > + return ctrl; > + > + conf = lm73_read(client, LM73_REG_CONF); > + if (conf < 0) > + return conf; > + > + /* strip out just the ALERT bit */ > + ctrl &= LM73_CTRL_ALERT_MASK; > + ctrl >>= LM73_CTRL_ALERT_SHIFT; > + > + /* > + * If ALERT's polarity is active-low, the bit needs to be > + * flipped to match the semantics of the 'alarm' attribute. > + */ > + if (!(conf & LM73_CONF_POL_MASK)) > + ctrl = !ctrl; > + > + return scnprintf(buf, PAGE_SIZE, "%d\n", ctrl); > +} > + > +static ssize_t show_maxmin_alarm(struct device *dev, > + struct device_attribute *da, > + char *buf) > +{ > + struct i2c_client *client = to_i2c_client(dev); > + struct sensor_device_attribute *attr = to_sensor_dev_attr(da); > + s32 ctrl; > + > + ctrl = lm73_read(client, LM73_REG_CTRL); > + if (ctrl < 0) > + return ctrl; > + > + /* strip out just the temperature hi/lo flag */ > + ctrl >>= attr->index; > + ctrl &= 0x1; > + > + return scnprintf(buf, PAGE_SIZE, "%d\n", ctrl); > +} > > /*-----------------------------------------------------------------------*/ > > @@ -90,13 +291,23 @@ static SENSOR_DEVICE_ATTR(temp1_min, S_IWUSR | S_IRUGO, > show_temp, set_temp, LM73_REG_MIN); > static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, > show_temp, NULL, LM73_REG_INPUT); > - > +static SENSOR_DEVICE_ATTR(temp1_update_interval, S_IWUSR | S_IRUGO, > + show_convrate, set_convrate, 0); > +static SENSOR_DEVICE_ATTR(temp1_alarm, S_IWUSR | S_IRUGO, > + show_alarm, reset_alarm, 0); > +static SENSOR_DEVICE_ATTR(temp1_max_alarm, S_IRUGO, > + show_maxmin_alarm, NULL, LM73_CTRL_HI_SHIFT); > +static SENSOR_DEVICE_ATTR(temp1_min_alarm, S_IRUGO, > + show_maxmin_alarm, NULL, LM73_CTRL_LO_SHIFT); > > static struct attribute *lm73_attributes[] = { > &sensor_dev_attr_temp1_input.dev_attr.attr, > &sensor_dev_attr_temp1_max.dev_attr.attr, > &sensor_dev_attr_temp1_min.dev_attr.attr, > - > + &sensor_dev_attr_temp1_update_interval.dev_attr.attr, > + &sensor_dev_attr_temp1_alarm.dev_attr.attr, > + &sensor_dev_attr_temp1_max_alarm.dev_attr.attr, > + &sensor_dev_attr_temp1_min_alarm.dev_attr.attr, > NULL > }; > > @@ -106,11 +317,25 @@ static const struct attribute_group lm73_group = { > > /*-----------------------------------------------------------------------*/ > > +static irqreturn_t lm73_alarm_irq(int irq, void *arg) > +{ > + struct i2c_client *client = arg; > + struct lm73_platform_data *data = client->dev.platform_data; > + > + sysfs_notify(&client->dev.kobj, NULL, "temp1_alarm"); > + if (data && data->handler) > + return data->handler(irq, arg); > + return IRQ_HANDLED; > +} > + > +/*-----------------------------------------------------------------------*/ > + > /* device probe and removal */ > > static int > lm73_probe(struct i2c_client *client, const struct i2c_device_id *id) > { > + struct lm73_platform_data *data = client->dev.platform_data; > struct device *hwmon_dev; > int status; > > @@ -126,6 +351,32 @@ lm73_probe(struct i2c_client *client, const struct i2c_device_id *id) > } > i2c_set_clientdata(client, hwmon_dev); > > + if (data && data->alert_polarity_high) { > + status = lm73_write_conf(client, 0, LM73_CONF_POL_MASK); > + if (status < 0) { > + dev_err(&client->dev, > + "%s: unable to set ALERT polarity\n", > + dev_name(hwmon_dev)); > + status = -EIO; > + goto exit_remove; > + } > + } > + > + if (data && data->use_irq) { > + status = devm_request_irq(&client->dev, > + data->irq, > + lm73_alarm_irq, > + data->irqflags, > + dev_name(hwmon_dev), > + client); > + if (status < 0) { > + dev_err(&client->dev, > + "%s: unable to assign IRQ %d\n", > + dev_name(hwmon_dev), data->irq); > + goto exit_remove; > + } > + } > + > dev_info(&client->dev, "%s: sensor '%s'\n", > dev_name(hwmon_dev), client->name); > > @@ -139,7 +390,11 @@ exit_remove: > static int lm73_remove(struct i2c_client *client) > { > struct device *hwmon_dev = i2c_get_clientdata(client); > + struct lm73_platform_data *data = client->dev.platform_data; > > + if (data && data->use_irq) > + devm_free_irq(&client->dev, data->use_irq, > + data->handler); > hwmon_device_unregister(hwmon_dev); > sysfs_remove_group(&client->dev.kobj, &lm73_group); > return 0; > diff --git a/include/linux/platform_data/lm73.h b/include/linux/platform_data/lm73.h > new file mode 100644 > index 0000000..bfe9382 > --- /dev/null > +++ b/include/linux/platform_data/lm73.h > @@ -0,0 +1,38 @@ > +/* > + * LM73 Sensor driver > + * Based on LM75 > + * > + * Copyright (C) 2007, CenoSYS (www.cenosys.com). > + * Copyright (C) 2009, Bollore telecom (www.bolloretelecom.eu). > + * > + * Guillaume Ligneul <guillaume.ligneul@xxxxxxxxx> > + * Adrien Demarez <adrien.demarez@xxxxxxxxxxxxxxxxx> > + * Jeremy Laine <jeremy.laine@xxxxxxxxxxxxxxxxx> > + * > + * This software program is licensed subject to the GNU General Public License > + * (GPL).Version 2,June 1991, available at > + * http://www.gnu.org/licenses/old-licenses/gpl-2.0.html > + */ > +#ifndef _LINUX_LM73_H > +#define _LINUX_LM73_H > + > +/** > + * struct lm73_platform_data - static configuration settings for the > + * LM73 temperature sensor. > + * > + * @alert_polarity_high: 0 if ALERT is active-high, 1 if active-low > + * @use_irq: 0 if ALERT is wired to an active interrupt pin > + * @irq: the interrupt to use > + * @irqflags: the interrupt flags (see IRQF_*) > + * @handler: the platform handler function > + */ > +struct lm73_platform_data { > + int alert_polarity_high; > + > + int use_irq; > + unsigned int irq; > + unsigned long irqflags; > + irq_handler_t handler; > +}; > + > +#endif /* _LINUX_LM73_H */ > -- > 1.7.9.5 > _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
