diff options
Diffstat (limited to 'drivers/hwmon/ab8500.c')
| -rw-r--r-- | drivers/hwmon/ab8500.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/drivers/hwmon/ab8500.c b/drivers/hwmon/ab8500.c new file mode 100644 index 00000000000..65a0f381d01 --- /dev/null +++ b/drivers/hwmon/ab8500.c @@ -0,0 +1,184 @@ +/* + * Copyright (C) ST-Ericsson SA 2010 + * Author: Martin Persson <martin.persson@stericsson.com> for + * ST-Ericsson. + * License terms: GNU Gereral Public License (GPL) version 2 + * + * Note: + * + * If/when the AB8500 thermal warning temperature is reached (threshold + * cannot be changed by SW), an interrupt is set and the driver + * notifies user space via a sysfs event. If a shut down is not + * triggered by user space within a certain time frame, + * pm_power off is called. + * + * If/when AB8500 thermal shutdown temperature is reached a hardware + * shutdown of the AB8500 will occur. + */ + +#include <linux/slab.h> +#include <linux/err.h> +#include <linux/hwmon.h> +#include <linux/sysfs.h> +#include <linux/hwmon-sysfs.h> +#include <linux/platform_device.h> +#include <linux/mfd/abx500/ab8500-gpadc.h> +#include <linux/mfd/abx500/ab8500-bm.h> +#include "abx500.h" +#include <asm/mach-types.h> + +#define DEFAULT_POWER_OFF_DELAY 10000 + +/* + * The driver monitors GPADC - ADC_AUX1, ADC_AUX2, BTEMP_BALL + * and BAT_CTRL. + */ +#define NUM_MONITORED_SENSORS 4 + +static int ab8500_read_sensor(struct abx500_temp *data, u8 sensor) +{ + int val; + /* + * Special treatment for the BAT_CTRL node, since this + * temperature measurement is more complex than just + * an ADC readout + */ + if (sensor == BAT_CTRL) + val = ab8500_btemp_get_batctrl_temp(data->ab8500_btemp); + else + val = ab8500_gpadc_convert(data->ab8500_gpadc, sensor); + + return val; +} + +static void ab8500_thermal_power_off(struct work_struct *work) +{ + struct abx500_temp *data = container_of(work, struct abx500_temp, + power_off_work.work); + + dev_warn(&data->pdev->dev, "Power off due to AB8500 thermal warning\n"); + pm_power_off(); +} + +static ssize_t ab8500_show_name(struct device *dev, + struct device_attribute *devattr, + char *buf) +{ + return sprintf(buf, "ab8500\n"); +} + +static ssize_t ab8500_show_label(struct device *dev, + struct device_attribute *devattr, + char *buf) +{ + char *name; + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); + int index = attr->index; + + /* + * Make sure these labels correspond to the attribute indexes + * used when calling SENSOR_DEVICE_ATRR. + * Temperature sensors outside ab8500 (read via GPADC) are marked + * with prefix ext_ + */ + switch (index) { + case 1: + name = "ext_rtc_xtal"; + break; + case 2: + name = "ext_db8500"; + break; + case 3: + name = "bat_temp"; + break; + case 4: + name = "bat_ctrl"; + break; + case 5: + name = "ab8500"; + break; + default: + return -EINVAL; + } + return sprintf(buf, "%s\n", name); +} + +static int ab8500_is_visible(struct attribute *attr, int n) +{ + if (!strcmp(attr->name, "temp5_input") || + !strcmp(attr->name, "temp5_min") || + !strcmp(attr->name, "temp5_max") || + !strcmp(attr->name, "temp5_max_hyst") || + !strcmp(attr->name, "temp5_min_alarm") || + !strcmp(attr->name, "temp5_max_alarm") || + !strcmp(attr->name, "temp5_max_hyst_alarm")) + return 0; + + return attr->mode; +} + +static int ab8500_temp_irq_handler(int irq, struct abx500_temp *data) +{ + unsigned long delay_in_jiffies; + /* + * Make sure the magic numbers below corresponds to the node + * used for AB8500 thermal warning from HW. + */ + mutex_lock(&data->lock); + data->crit_alarm[4] = 1; + mutex_unlock(&data->lock); + + hwmon_notify(data->crit_alarm[4], NULL); + sysfs_notify(&data->pdev->dev.kobj, NULL, "temp5_crit_alarm"); + dev_info(&data->pdev->dev, "AB8500 thermal warning," + " power off in %lu s\n", data->power_off_delay); + delay_in_jiffies = msecs_to_jiffies(data->power_off_delay); + schedule_delayed_work(&data->power_off_work, delay_in_jiffies); + return 0; +} + +int __init ab8500_hwmon_init(struct abx500_temp *data) +{ + data->ab8500_gpadc = ab8500_gpadc_get("ab8500-gpadc.0"); + if (IS_ERR(data->ab8500_gpadc)) + return PTR_ERR(data->ab8500_gpadc); + + data->ab8500_btemp = ab8500_btemp_get(); + if (IS_ERR(data->ab8500_btemp)) + return PTR_ERR(data->ab8500_btemp); + + INIT_DELAYED_WORK(&data->power_off_work, ab8500_thermal_power_off); + + /* + * Setup HW defined data. + * + * Reference hardware (HREF): + * + * GPADC - ADC_AUX1, connected to NTC R2148 next to RTC_XTAL on HREF + * GPADC - ADC_AUX2, connected to NTC R2150 near DB8500 on HREF + * Hence, temp#_min/max/max_hyst refer to millivolts and not + * millidegrees + * This is not the case for BAT_CTRL where millidegrees is used + * + * HREF HW does not support reading AB8500 temperature. BUT an + * AB8500 IRQ will be launched if die crit temp limit is reached. + * + * Make sure indexes correspond to the attribute indexes + * used when calling SENSOR_DEVICE_ATRR + */ + data->gpadc_addr[0] = ADC_AUX1; + data->gpadc_addr[1] = ADC_AUX2; + data->gpadc_addr[2] = BTEMP_BALL; + data->gpadc_addr[3] = BAT_CTRL; + data->gpadc_addr[4] = DIE_TEMP; + data->power_off_delay = DEFAULT_POWER_OFF_DELAY; + data->monitored_sensors = NUM_MONITORED_SENSORS; + + data->ops.read_sensor = ab8500_read_sensor; + data->ops.irq_handler = ab8500_temp_irq_handler; + data->ops.show_name = ab8500_show_name; + data->ops.show_label = ab8500_show_label; + data->ops.is_visible = ab8500_is_visible; + + return 0; +} |