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Release 4.14 drivers/hwmon/ab8500.c

Directory: drivers/hwmon
/*
 * Copyright (C) ST-Ericsson 2010 - 2013
 * Author: Martin Persson <martin.persson@stericsson.com>
 *         Hongbo Zhang <hongbo.zhang@linaro.org>
 * License Terms: GNU General Public License v2
 *
 * When the AB8500 thermal warning temperature is reached (threshold cannot
 * be changed by SW), an interrupt is set, and if no further action is taken
 * within a certain time frame, kernel_power_off will be called.
 *
 * When AB8500 thermal shutdown temperature is reached a hardware shutdown of
 * the AB8500 will occur.
 */

#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/mfd/abx500.h>
#include <linux/mfd/abx500/ab8500-bm.h>
#include <linux/mfd/abx500/ab8500-gpadc.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/power/ab8500.h>
#include <linux/reboot.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include "abx500.h"


#define DEFAULT_POWER_OFF_DELAY	(HZ * 10)

#define THERMAL_VCC		1800

#define PULL_UP_RESISTOR	47000
/* Number of monitored sensors should not greater than NUM_SENSORS */

#define NUM_MONITORED_SENSORS	4


struct ab8500_gpadc_cfg {
	
const struct abx500_res_to_temp *temp_tbl;
	
int tbl_sz;
	
int vcc;
	
int r_up;
};


struct ab8500_temp {
	
struct ab8500_gpadc *gpadc;
	
struct ab8500_btemp *btemp;
	
struct delayed_work power_off_work;
	
struct ab8500_gpadc_cfg cfg;
	
struct abx500_temp *abx500_data;
};

/*
 * The hardware connection is like this:
 * VCC----[ R_up ]-----[ NTC ]----GND
 * where R_up is pull-up resistance, and GPADC measures voltage on NTC.
 * and res_to_temp table is strictly sorted by falling resistance values.
 */

static int ab8500_voltage_to_temp(struct ab8500_gpadc_cfg *cfg, int v_ntc, int *temp) { int r_ntc, i = 0, tbl_sz = cfg->tbl_sz; const struct abx500_res_to_temp *tbl = cfg->temp_tbl; if (cfg->vcc < 0 || v_ntc >= cfg->vcc) return -EINVAL; r_ntc = v_ntc * cfg->r_up / (cfg->vcc - v_ntc); if (r_ntc > tbl[0].resist || r_ntc < tbl[tbl_sz - 1].resist) return -EINVAL; while (!(r_ntc <= tbl[i].resist && r_ntc > tbl[i + 1].resist) && i < tbl_sz - 2) i++; /* return milli-Celsius */ *temp = tbl[i].temp * 1000 + ((tbl[i + 1].temp - tbl[i].temp) * 1000 * (r_ntc - tbl[i].resist)) / (tbl[i + 1].resist - tbl[i].resist); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Hongbo Zhang202100.00%1100.00%
Total202100.00%1100.00%


static int ab8500_read_sensor(struct abx500_temp *data, u8 sensor, int *temp) { int voltage, ret; struct ab8500_temp *ab8500_data = data->plat_data; if (sensor == BAT_CTRL) { *temp = ab8500_btemp_get_batctrl_temp(ab8500_data->btemp); } else if (sensor == BTEMP_BALL) { *temp = ab8500_btemp_get_temp(ab8500_data->btemp); } else { voltage = ab8500_gpadc_convert(ab8500_data->gpadc, sensor); if (voltage < 0) return voltage; ret = ab8500_voltage_to_temp(&ab8500_data->cfg, voltage, temp); if (ret < 0) return ret; } return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Hongbo Zhang118100.00%1100.00%
Total118100.00%1100.00%


static void ab8500_thermal_power_off(struct work_struct *work) { struct ab8500_temp *ab8500_data = container_of(work, struct ab8500_temp, power_off_work.work); struct abx500_temp *abx500_data = ab8500_data->abx500_data; dev_warn(&abx500_data->pdev->dev, "Power off due to critical temp\n"); kernel_power_off(); }

Contributors

PersonTokensPropCommitsCommitProp
Hongbo Zhang5198.08%150.00%
Guenter Roeck11.92%150.00%
Total52100.00%2100.00%


static ssize_t ab8500_show_name(struct device *dev, struct device_attribute *devattr, char *buf) { return sprintf(buf, "ab8500\n"); }

Contributors

PersonTokensPropCommitsCommitProp
Hongbo Zhang28100.00%1100.00%
Total28100.00%1100.00%


static ssize_t ab8500_show_label(struct device *dev, struct device_attribute *devattr, char *buf) { char *label; struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); int index = attr->index; switch (index) { case 1: label = "ext_adc1"; break; case 2: label = "ext_adc2"; break; case 3: label = "bat_temp"; break; case 4: label = "bat_ctrl"; break; default: return -EINVAL; } return sprintf(buf, "%s\n", label); }

Contributors

PersonTokensPropCommitsCommitProp
Hongbo Zhang94100.00%1100.00%
Total94100.00%1100.00%


static int ab8500_temp_irq_handler(int irq, struct abx500_temp *data) { struct ab8500_temp *ab8500_data = data->plat_data; dev_warn(&data->pdev->dev, "Power off in %d s\n", DEFAULT_POWER_OFF_DELAY / HZ); schedule_delayed_work(&ab8500_data->power_off_work, DEFAULT_POWER_OFF_DELAY); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Hongbo Zhang52100.00%1100.00%
Total52100.00%1100.00%


int abx500_hwmon_init(struct abx500_temp *data) { struct ab8500_temp *ab8500_data; ab8500_data = devm_kzalloc(&data->pdev->dev, sizeof(*ab8500_data), GFP_KERNEL); if (!ab8500_data) return -ENOMEM; ab8500_data->gpadc = ab8500_gpadc_get("ab8500-gpadc.0"); if (IS_ERR(ab8500_data->gpadc)) return PTR_ERR(ab8500_data->gpadc); ab8500_data->btemp = ab8500_btemp_get(); if (IS_ERR(ab8500_data->btemp)) return PTR_ERR(ab8500_data->btemp); INIT_DELAYED_WORK(&ab8500_data->power_off_work, ab8500_thermal_power_off); ab8500_data->cfg.vcc = THERMAL_VCC; ab8500_data->cfg.r_up = PULL_UP_RESISTOR; ab8500_data->cfg.temp_tbl = ab8500_temp_tbl_a_thermistor; ab8500_data->cfg.tbl_sz = ab8500_temp_tbl_a_size; data->plat_data = ab8500_data; /* * ADC_AUX1 and ADC_AUX2, connected to external NTC * BTEMP_BALL and BAT_CTRL, fixed usage */ 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->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 = NULL; return 0; }

Contributors

PersonTokensPropCommitsCommitProp
Hongbo Zhang228100.00%1100.00%
Total228100.00%1100.00%

EXPORT_SYMBOL(abx500_hwmon_init); MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@linaro.org>"); MODULE_DESCRIPTION("AB8500 temperature driver"); MODULE_LICENSE("GPL");

Overall Contributors

PersonTokensPropCommitsCommitProp
Hongbo Zhang89599.44%150.00%
Guenter Roeck50.56%150.00%
Total900100.00%2100.00%
Directory: drivers/hwmon
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