ds2760_battery: add current_accum module parameter

When connecting a ds2760 to a partly loaded battery the first time,
there must be a way to bootstrap the current_accum value. Without that,
the current capactity value is bogus until the battery is fully charged
for the first time.

Signed-off-by: Daniel Mack <daniel@caiaq.de>
Cc: Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
Cc: Matt Reimer <mreimer@vpop.net>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

1 files changed, 27 insertions, 14 deletions

diff --git a/drivers/power/ds2760_battery.c b/drivers/power/ds2760_battery.c
index 2d0e5edb4742..f4a9258aa9d0 100644
--- a/drivers/power/ds2760_battery.c
+++ b/drivers/power/ds2760_battery.c
@@ -70,6 +70,10 @@ static unsigned int rated_capacity;
 module_param(rated_capacity, uint, 0644);
 MODULE_PARM_DESC(rated_capacity, "rated battery capacity, 10*mAh or index");
 
+static unsigned int current_accum;
+module_param(current_accum, uint, 0644);
+MODULE_PARM_DESC(current_accum, "current accumulator value");
+
 /* Some batteries have their rated capacity stored a N * 10 mAh, while
  * others use an index into this table. */
 static int rated_capacities[] = {
@@ -215,6 +219,22 @@ static int ds2760_battery_read_status(struct ds2760_device_info *di)
         return 0;
 }
 
+static void ds2760_battery_set_current_accum(struct ds2760_device_info *di,
+                                             unsigned int acr_val)
+{
+        unsigned char acr[2];
+
+        /* acr is in units of 0.25 mAh */
+        acr_val *= 4L;
+        acr_val /= 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 write failed\n");
+}
+
 static void ds2760_battery_update_status(struct ds2760_device_info *di)
 {
         int old_charge_status = di->charge_status;
@@ -246,21 +266,9 @@ static void ds2760_battery_update_status(struct ds2760_device_info *di)
                         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;
+                                ds2760_battery_set_current_accum(di,
+                                                di->full_active_uAh);
                         }
                 }
         } else {
@@ -423,6 +431,11 @@ static int ds2760_battery_probe(struct platform_device *pdev)
         if (rated_capacity)
                 ds2760_battery_write_rated_capacity(di, rated_capacity);
 
+        /* set current accumulator if given as parameter.
+         * this should only be done for bootstrapping the value */
+        if (current_accum)
+                ds2760_battery_set_current_accum(di, current_accum);
+
         retval = power_supply_register(&pdev->dev, &di->bat);
         if (retval) {
                 dev_err(di->dev, "failed to register battery\n");