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path: root/drivers/power/ds2760_battery.c
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Diffstat (limited to 'drivers/power/ds2760_battery.c')
-rw-r--r--drivers/power/ds2760_battery.c470
1 files changed, 470 insertions, 0 deletions
diff --git a/drivers/power/ds2760_battery.c b/drivers/power/ds2760_battery.c
new file mode 100644
index 000000000000..00e1ea6f1de2
--- /dev/null
+++ b/drivers/power/ds2760_battery.c
@@ -0,0 +1,470 @@
+/*
+ * Driver for batteries with DS2760 chips inside.
+ *
+ * Copyright © 2007 Anton Vorontsov
+ * 2004-2007 Matt Reimer
+ * 2004 Szabolcs Gyurko
+ *
+ * Use consistent with the GNU GPL is permitted,
+ * provided that this copyright notice is
+ * preserved in its entirety in all copies and derived works.
+ *
+ * Author: Anton Vorontsov <cbou@mail.ru>
+ * February 2007
+ *
+ * Matt Reimer <mreimer@vpop.net>
+ * April 2004, 2005, 2007
+ *
+ * Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
+ * September 2004
+ */
+
+#include <linux/module.h>
+#include <linux/param.h>
+#include <linux/jiffies.h>
+#include <linux/workqueue.h>
+#include <linux/pm.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+
+#include "../w1/w1.h"
+#include "../w1/slaves/w1_ds2760.h"
+
+struct ds2760_device_info {
+ struct device *dev;
+
+ /* DS2760 data, valid after calling ds2760_battery_read_status() */
+ unsigned long update_time; /* jiffies when data read */
+ char raw[DS2760_DATA_SIZE]; /* raw DS2760 data */
+ int voltage_raw; /* units of 4.88 mV */
+ int voltage_uV; /* units of µV */
+ int current_raw; /* units of 0.625 mA */
+ int current_uA; /* units of µA */
+ int accum_current_raw; /* units of 0.25 mAh */
+ int accum_current_uAh; /* units of µAh */
+ int temp_raw; /* units of 0.125 °C */
+ int temp_C; /* units of 0.1 °C */
+ int rated_capacity; /* units of µAh */
+ int rem_capacity; /* percentage */
+ int full_active_uAh; /* units of µAh */
+ int empty_uAh; /* units of µAh */
+ int life_sec; /* units of seconds */
+ int charge_status; /* POWER_SUPPLY_STATUS_* */
+
+ int full_counter;
+ struct power_supply bat;
+ struct device *w1_dev;
+ struct workqueue_struct *monitor_wqueue;
+ struct delayed_work monitor_work;
+};
+
+static unsigned int cache_time = 1000;
+module_param(cache_time, uint, 0644);
+MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
+
+/* Some batteries have their rated capacity stored a N * 10 mAh, while
+ * others use an index into this table. */
+static int rated_capacities[] = {
+ 0,
+ 920, /* Samsung */
+ 920, /* BYD */
+ 920, /* Lishen */
+ 920, /* NEC */
+ 1440, /* Samsung */
+ 1440, /* BYD */
+ 1440, /* Lishen */
+ 1440, /* NEC */
+ 2880, /* Samsung */
+ 2880, /* BYD */
+ 2880, /* Lishen */
+ 2880 /* NEC */
+};
+
+/* array is level at temps 0°C, 10°C, 20°C, 30°C, 40°C
+ * temp is in Celsius */
+static int battery_interpolate(int array[], int temp)
+{
+ int index, dt;
+
+ if (temp <= 0)
+ return array[0];
+ if (temp >= 40)
+ return array[4];
+
+ index = temp / 10;
+ dt = temp % 10;
+
+ return array[index] + (((array[index + 1] - array[index]) * dt) / 10);
+}
+
+static int ds2760_battery_read_status(struct ds2760_device_info *di)
+{
+ int ret, i, start, count, scale[5];
+
+ if (di->update_time && time_before(jiffies, di->update_time +
+ msecs_to_jiffies(cache_time)))
+ return 0;
+
+ /* The first time we read the entire contents of SRAM/EEPROM,
+ * but after that we just read the interesting bits that change. */
+ if (di->update_time == 0) {
+ start = 0;
+ count = DS2760_DATA_SIZE;
+ } else {
+ start = DS2760_VOLTAGE_MSB;
+ count = DS2760_TEMP_LSB - start + 1;
+ }
+
+ ret = w1_ds2760_read(di->w1_dev, di->raw + start, start, count);
+ if (ret != count) {
+ dev_warn(di->dev, "call to w1_ds2760_read failed (0x%p)\n",
+ di->w1_dev);
+ return 1;
+ }
+
+ di->update_time = jiffies;
+
+ /* DS2760 reports voltage in units of 4.88mV, but the battery class
+ * reports in units of uV, so convert by multiplying by 4880. */
+ di->voltage_raw = (di->raw[DS2760_VOLTAGE_MSB] << 3) |
+ (di->raw[DS2760_VOLTAGE_LSB] >> 5);
+ di->voltage_uV = di->voltage_raw * 4880;
+
+ /* DS2760 reports current in signed units of 0.625mA, but the battery
+ * class reports in units of µA, so convert by multiplying by 625. */
+ di->current_raw =
+ (((signed char)di->raw[DS2760_CURRENT_MSB]) << 5) |
+ (di->raw[DS2760_CURRENT_LSB] >> 3);
+ di->current_uA = di->current_raw * 625;
+
+ /* DS2760 reports accumulated current in signed units of 0.25mAh. */
+ di->accum_current_raw =
+ (((signed char)di->raw[DS2760_CURRENT_ACCUM_MSB]) << 8) |
+ di->raw[DS2760_CURRENT_ACCUM_LSB];
+ di->accum_current_uAh = di->accum_current_raw * 250;
+
+ /* DS2760 reports temperature in signed units of 0.125°C, but the
+ * battery class reports in units of 1/10 °C, so we convert by
+ * multiplying by .125 * 10 = 1.25. */
+ di->temp_raw = (((signed char)di->raw[DS2760_TEMP_MSB]) << 3) |
+ (di->raw[DS2760_TEMP_LSB] >> 5);
+ di->temp_C = di->temp_raw + (di->temp_raw / 4);
+
+ /* At least some battery monitors (e.g. HP iPAQ) store the battery's
+ * maximum rated capacity. */
+ if (di->raw[DS2760_RATED_CAPACITY] < ARRAY_SIZE(rated_capacities))
+ di->rated_capacity = rated_capacities[
+ (unsigned int)di->raw[DS2760_RATED_CAPACITY]];
+ else
+ di->rated_capacity = di->raw[DS2760_RATED_CAPACITY] * 10;
+
+ di->rated_capacity *= 1000; /* convert to µAh */
+
+ /* Calculate the full level at the present temperature. */
+ di->full_active_uAh = di->raw[DS2760_ACTIVE_FULL] << 8 |
+ di->raw[DS2760_ACTIVE_FULL + 1];
+
+ scale[0] = di->raw[DS2760_ACTIVE_FULL] << 8 |
+ di->raw[DS2760_ACTIVE_FULL + 1];
+ for (i = 1; i < 5; i++)
+ scale[i] = scale[i - 1] + di->raw[DS2760_ACTIVE_FULL + 2 + i];
+
+ di->full_active_uAh = battery_interpolate(scale, di->temp_C / 10);
+ di->full_active_uAh *= 1000; /* convert to µAh */
+
+ /* Calculate the empty level at the present temperature. */
+ scale[4] = di->raw[DS2760_ACTIVE_EMPTY + 4];
+ for (i = 3; i >= 0; i--)
+ scale[i] = scale[i + 1] + di->raw[DS2760_ACTIVE_EMPTY + i];
+
+ di->empty_uAh = battery_interpolate(scale, di->temp_C / 10);
+ di->empty_uAh *= 1000; /* convert to µAh */
+
+ /* From Maxim Application Note 131: remaining capacity =
+ * ((ICA - Empty Value) / (Full Value - Empty Value)) x 100% */
+ di->rem_capacity = ((di->accum_current_uAh - di->empty_uAh) * 100L) /
+ (di->full_active_uAh - di->empty_uAh);
+
+ if (di->rem_capacity < 0)
+ di->rem_capacity = 0;
+ if (di->rem_capacity > 100)
+ di->rem_capacity = 100;
+
+ if (di->current_uA)
+ di->life_sec = -((di->accum_current_uAh - di->empty_uAh) *
+ 3600L) / di->current_uA;
+ else
+ di->life_sec = 0;
+
+ return 0;
+}
+
+static void ds2760_battery_update_status(struct ds2760_device_info *di)
+{
+ int old_charge_status = di->charge_status;
+
+ ds2760_battery_read_status(di);
+
+ if (di->charge_status == POWER_SUPPLY_STATUS_UNKNOWN)
+ di->full_counter = 0;
+
+ if (power_supply_am_i_supplied(&di->bat)) {
+ if (di->current_uA > 10000) {
+ di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
+ di->full_counter = 0;
+ } else if (di->current_uA < -5000) {
+ if (di->charge_status != POWER_SUPPLY_STATUS_NOT_CHARGING)
+ dev_notice(di->dev, "not enough power to "
+ "charge\n");
+ di->charge_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
+ di->full_counter = 0;
+ } else if (di->current_uA < 10000 &&
+ di->charge_status != POWER_SUPPLY_STATUS_FULL) {
+
+ /* Don't consider the battery to be full unless
+ * we've seen the current < 10 mA at least two
+ * consecutive times. */
+
+ di->full_counter++;
+
+ if (di->full_counter < 2) {
+ di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
+ } else {
+ unsigned char acr[2];
+ int acr_val;
+
+ /* acr is in units of 0.25 mAh */
+ acr_val = di->full_active_uAh * 4L / 1000;
+
+ acr[0] = acr_val >> 8;
+ acr[1] = acr_val & 0xff;
+
+ if (w1_ds2760_write(di->w1_dev, acr,
+ DS2760_CURRENT_ACCUM_MSB, 2) < 2)
+ dev_warn(di->dev,
+ "ACR reset failed\n");
+
+ di->charge_status = POWER_SUPPLY_STATUS_FULL;
+ }
+ }
+ } else {
+ di->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
+ di->full_counter = 0;
+ }
+
+ if (di->charge_status != old_charge_status)
+ power_supply_changed(&di->bat);
+
+ return;
+}
+
+static void ds2760_battery_work(struct work_struct *work)
+{
+ struct ds2760_device_info *di = container_of(work,
+ struct ds2760_device_info, monitor_work.work);
+ const int interval = HZ * 60;
+
+ dev_dbg(di->dev, "%s\n", __FUNCTION__);
+
+ ds2760_battery_update_status(di);
+ queue_delayed_work(di->monitor_wqueue, &di->monitor_work, interval);
+
+ return;
+}
+
+#define to_ds2760_device_info(x) container_of((x), struct ds2760_device_info, \
+ bat);
+
+static void ds2760_battery_external_power_changed(struct power_supply *psy)
+{
+ struct ds2760_device_info *di = to_ds2760_device_info(psy);
+
+ dev_dbg(di->dev, "%s\n", __FUNCTION__);
+
+ cancel_delayed_work(&di->monitor_work);
+ queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ/10);
+
+ return;
+}
+
+static int ds2760_battery_get_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ struct ds2760_device_info *di = to_ds2760_device_info(psy);
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_STATUS:
+ val->intval = di->charge_status;
+ return 0;
+ default:
+ break;
+ }
+
+ ds2760_battery_read_status(di);
+
+ switch (psp) {
+ case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+ val->intval = di->voltage_uV;
+ break;
+ case POWER_SUPPLY_PROP_CURRENT_NOW:
+ val->intval = di->current_uA;
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+ val->intval = di->rated_capacity;
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_FULL:
+ val->intval = di->full_active_uAh;
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_EMPTY:
+ val->intval = di->empty_uAh;
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_NOW:
+ val->intval = di->accum_current_uAh;
+ break;
+ case POWER_SUPPLY_PROP_TEMP:
+ val->intval = di->temp_C;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static enum power_supply_property ds2760_battery_props[] = {
+ POWER_SUPPLY_PROP_STATUS,
+ POWER_SUPPLY_PROP_VOLTAGE_NOW,
+ POWER_SUPPLY_PROP_CURRENT_NOW,
+ POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
+ POWER_SUPPLY_PROP_CHARGE_FULL,
+ POWER_SUPPLY_PROP_CHARGE_EMPTY,
+ POWER_SUPPLY_PROP_CHARGE_NOW,
+ POWER_SUPPLY_PROP_TEMP,
+};
+
+static int ds2760_battery_probe(struct platform_device *pdev)
+{
+ int retval = 0;
+ struct ds2760_device_info *di;
+ struct ds2760_platform_data *pdata;
+
+ di = kzalloc(sizeof(*di), GFP_KERNEL);
+ if (!di) {
+ retval = -ENOMEM;
+ goto di_alloc_failed;
+ }
+
+ platform_set_drvdata(pdev, di);
+
+ pdata = pdev->dev.platform_data;
+ di->dev = &pdev->dev;
+ di->w1_dev = pdev->dev.parent;
+ di->bat.name = pdev->dev.bus_id;
+ di->bat.type = POWER_SUPPLY_TYPE_BATTERY;
+ di->bat.properties = ds2760_battery_props;
+ di->bat.num_properties = ARRAY_SIZE(ds2760_battery_props);
+ di->bat.get_property = ds2760_battery_get_property;
+ di->bat.external_power_changed =
+ ds2760_battery_external_power_changed;
+
+ di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
+
+ retval = power_supply_register(&pdev->dev, &di->bat);
+ if (retval) {
+ dev_err(di->dev, "failed to register battery");
+ goto batt_failed;
+ }
+
+ INIT_DELAYED_WORK(&di->monitor_work, ds2760_battery_work);
+ di->monitor_wqueue = create_singlethread_workqueue(pdev->dev.bus_id);
+ if (!di->monitor_wqueue) {
+ retval = -ESRCH;
+ goto workqueue_failed;
+ }
+ queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ * 1);
+
+ goto success;
+
+workqueue_failed:
+ power_supply_unregister(&di->bat);
+batt_failed:
+ kfree(di);
+di_alloc_failed:
+success:
+ return retval;
+}
+
+static int ds2760_battery_remove(struct platform_device *pdev)
+{
+ struct ds2760_device_info *di = platform_get_drvdata(pdev);
+
+ cancel_rearming_delayed_workqueue(di->monitor_wqueue,
+ &di->monitor_work);
+ destroy_workqueue(di->monitor_wqueue);
+ power_supply_unregister(&di->bat);
+
+ return 0;
+}
+
+#ifdef CONFIG_PM
+
+static int ds2760_battery_suspend(struct platform_device *pdev,
+ pm_message_t state)
+{
+ struct ds2760_device_info *di = platform_get_drvdata(pdev);
+
+ di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
+
+ return 0;
+}
+
+static int ds2760_battery_resume(struct platform_device *pdev)
+{
+ struct ds2760_device_info *di = platform_get_drvdata(pdev);
+
+ di->charge_status = POWER_SUPPLY_STATUS_UNKNOWN;
+ power_supply_changed(&di->bat);
+
+ cancel_delayed_work(&di->monitor_work);
+ queue_delayed_work(di->monitor_wqueue, &di->monitor_work, HZ);
+
+ return 0;
+}
+
+#else
+
+#define ds2760_battery_suspend NULL
+#define ds2760_battery_resume NULL
+
+#endif /* CONFIG_PM */
+
+static struct platform_driver ds2760_battery_driver = {
+ .driver = {
+ .name = "ds2760-battery",
+ },
+ .probe = ds2760_battery_probe,
+ .remove = ds2760_battery_remove,
+ .suspend = ds2760_battery_suspend,
+ .resume = ds2760_battery_resume,
+};
+
+static int __init ds2760_battery_init(void)
+{
+ return platform_driver_register(&ds2760_battery_driver);
+}
+
+static void __exit ds2760_battery_exit(void)
+{
+ platform_driver_unregister(&ds2760_battery_driver);
+ return;
+}
+
+module_init(ds2760_battery_init);
+module_exit(ds2760_battery_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>, "
+ "Matt Reimer <mreimer@vpop.net>, "
+ "Anton Vorontsov <cbou@mail.ru>");
+MODULE_DESCRIPTION("ds2760 battery driver");
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-22 17:58:51 +0000