--- /dev/null
+/*
+ * 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;
+}
+
+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;
+}
+
+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();
+}
+
+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 *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);
+}
+
+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;
+}
+
+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;
+}
+EXPORT_SYMBOL(abx500_hwmon_init);
+
+MODULE_AUTHOR("Hongbo Zhang <hongbo.zhang@linaro.org>");
+MODULE_DESCRIPTION("AB8500 temperature driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff