[BATTERY] 1-Wire ds2760 chip battery driver
authorAnton Vorontsov <cbou@mail.ru>
Thu, 3 May 2007 20:45:39 +0000 (00:45 +0400)
committerDavid Woodhouse <dwmw2@infradead.org>
Tue, 10 Jul 2007 10:26:18 +0000 (11:26 +0100)
This is driver for batteries with ds2760 chip inside, found inside
almost every HP iPaq and HTC PDAs/phones.

Signed-off-by: Anton Vorontsov <cbou@mail.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
drivers/power/Kconfig
drivers/power/Makefile
drivers/power/ds2760_battery.c [new file with mode: 0644]

index 791fa0cc45fec8e2033e55b949267883b7b834e9..921456243e4bed5e2c89b5b3dd590ce9ebb3ee3d 100644 (file)
@@ -28,4 +28,11 @@ config APM_POWER
          Say Y here to enable support APM status emulation using
          battery class devices.
 
+config BATTERY_DS2760
+       tristate "DS2760 battery driver (HP iPAQ & others)"
+       select W1
+       select W1_SLAVE_DS2760
+       help
+         Say Y here to enable support for batteries with ds2760 chip.
+
 endif # POWER_SUPPLY
index 7779cebcb3ae01fb254d88b275bb6a20e4545a98..a978ba15f6c56e78f4f83342fb4bad33b8d94d81 100644 (file)
@@ -16,3 +16,5 @@ obj-$(CONFIG_POWER_SUPPLY)    += power_supply.o
 
 obj-$(CONFIG_PDA_POWER)                += pda_power.o
 obj-$(CONFIG_APM_POWER)                += apm_power.o
+
+obj-$(CONFIG_BATTERY_DS2760)   += ds2760_battery.o
diff --git a/drivers/power/ds2760_battery.c b/drivers/power/ds2760_battery.c
new file mode 100644 (file)
index 0000000..00e1ea6
--- /dev/null
@@ -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");