Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755350Ab1ESXBg (ORCPT ); Thu, 19 May 2011 19:01:36 -0400 Received: from hqemgate04.nvidia.com ([216.228.121.35]:8725 "EHLO hqemgate04.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751998Ab1ESXBf (ORCPT ); Thu, 19 May 2011 19:01:35 -0400 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Thu, 19 May 2011 16:01:34 -0700 From: Rhyland Klein To: cbouatmailru@gmail.com Cc: bleung@google.com, olof@lixom.net, linux-kernel@vger.kernel.org, Rhyland Klein Subject: [PATCH 1/2] power: bq20z75: support external notification Date: Thu, 19 May 2011 16:00:03 -0700 Message-Id: <1305846004-11895-1-git-send-email-rklein@nvidia.com> X-Mailer: git-send-email 1.7.5.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6817 Lines: 203 Adding support for external power change notification. One problem found is that there is a lag time before the sensor will return a new status. To ensure that we only fire off the power_supply_changed event when the status returned from the sensor is actually different, we delay sending the the notification, and instead poll on it looking for a change. The amount of time to poll is configurable via platform data. Signed-off-by: Rhyland Klein --- drivers/power/bq20z75.c | 103 +++++++++++++++++++++++++++++++++++++---- include/linux/power/bq20z75.h | 3 + 2 files changed, 97 insertions(+), 9 deletions(-) diff --git a/drivers/power/bq20z75.c b/drivers/power/bq20z75.c index 506585e..9c5e5be 100644 --- a/drivers/power/bq20z75.c +++ b/drivers/power/bq20z75.c @@ -152,6 +152,10 @@ struct bq20z75_info { bool gpio_detect; bool enable_detection; int irq; + int last_state; + int poll_time; + struct delayed_work work; + int ignore_changes; }; static int bq20z75_read_word_data(struct i2c_client *client, u8 address) @@ -279,6 +283,7 @@ static int bq20z75_get_battery_property(struct i2c_client *client, int reg_offset, enum power_supply_property psp, union power_supply_propval *val) { + struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client); s32 ret; ret = bq20z75_read_word_data(client, @@ -293,15 +298,24 @@ static int bq20z75_get_battery_property(struct i2c_client *client, if (ret >= bq20z75_data[reg_offset].min_value && ret <= bq20z75_data[reg_offset].max_value) { val->intval = ret; - if (psp == POWER_SUPPLY_PROP_STATUS) { - if (ret & BATTERY_FULL_CHARGED) - val->intval = POWER_SUPPLY_STATUS_FULL; - else if (ret & BATTERY_FULL_DISCHARGED) - val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; - else if (ret & BATTERY_DISCHARGING) - val->intval = POWER_SUPPLY_STATUS_DISCHARGING; - else - val->intval = POWER_SUPPLY_STATUS_CHARGING; + if (psp != POWER_SUPPLY_PROP_STATUS) + return 0; + + if (ret & BATTERY_FULL_CHARGED) + val->intval = POWER_SUPPLY_STATUS_FULL; + else if (ret & BATTERY_FULL_DISCHARGED) + val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING; + else if (ret & BATTERY_DISCHARGING) + val->intval = POWER_SUPPLY_STATUS_DISCHARGING; + else + val->intval = POWER_SUPPLY_STATUS_CHARGING; + + if (bq20z75_device->poll_time == 0) + bq20z75_device->last_state = val->intval; + else if (bq20z75_device->last_state != val->intval) { + cancel_delayed_work_sync(&bq20z75_device->work); + power_supply_changed(&bq20z75_device->power_supply); + bq20z75_device->poll_time = 0; } } else { if (psp == POWER_SUPPLY_PROP_STATUS) @@ -545,6 +559,60 @@ static irqreturn_t bq20z75_irq(int irq, void *devid) return IRQ_HANDLED; } +static void bq20z75_external_power_changed(struct power_supply *psy) +{ + struct bq20z75_info *bq20z75_device; + + bq20z75_device = container_of(psy, struct bq20z75_info, power_supply); + + if (bq20z75_device->ignore_changes > 0) { + bq20z75_device->ignore_changes--; + return; + } + + /* cancel outstanding work */ + cancel_delayed_work_sync(&bq20z75_device->work); + + schedule_delayed_work(&bq20z75_device->work, HZ); + bq20z75_device->poll_time = bq20z75_device->pdata->poll_retry_count; +} + +static void bq20z75_delayed_work(struct work_struct *work) +{ + struct bq20z75_info *bq20z75_device; + s32 ret; + + bq20z75_device = container_of(work, struct bq20z75_info, work.work); + + ret = bq20z75_read_word_data(bq20z75_device->client, + bq20z75_data[REG_STATUS].addr); + /* if the read failed, give up on this work */ + if (ret < 0) { + bq20z75_device->poll_time = 0; + return; + } + + if (ret & BATTERY_FULL_CHARGED) + ret = POWER_SUPPLY_STATUS_FULL; + else if (ret & BATTERY_FULL_DISCHARGED) + ret = POWER_SUPPLY_STATUS_NOT_CHARGING; + else if (ret & BATTERY_DISCHARGING) + ret = POWER_SUPPLY_STATUS_DISCHARGING; + else + ret = POWER_SUPPLY_STATUS_CHARGING; + + if (bq20z75_device->last_state != ret) { + bq20z75_device->poll_time = 0; + power_supply_changed(&bq20z75_device->power_supply); + return; + } + if (bq20z75_device->poll_time > 0) { + schedule_delayed_work(&bq20z75_device->work, HZ); + bq20z75_device->poll_time--; + return; + } +} + static int __devinit bq20z75_probe(struct i2c_client *client, const struct i2c_device_id *id) { @@ -566,6 +634,13 @@ static int __devinit bq20z75_probe(struct i2c_client *client, bq20z75_device->power_supply.num_properties = ARRAY_SIZE(bq20z75_properties); bq20z75_device->power_supply.get_property = bq20z75_get_property; + /* ignore first notification of external change, it is generated + * from the power_supply_register call back + */ + bq20z75_device->ignore_changes = 1; + bq20z75_device->last_state = POWER_SUPPLY_STATUS_UNKNOWN; + bq20z75_device->power_supply.external_power_changed = + bq20z75_external_power_changed; if (pdata) { bq20z75_device->gpio_detect = @@ -625,6 +700,10 @@ skip_gpio: dev_info(&client->dev, "%s: battery gas gauge device registered\n", client->name); + INIT_DELAYED_WORK(&bq20z75_device->work, bq20z75_delayed_work); + + bq20z75_device->enable_detection = true; + return 0; exit_psupply: @@ -648,6 +727,9 @@ static int __devexit bq20z75_remove(struct i2c_client *client) gpio_free(bq20z75_device->pdata->battery_detect); power_supply_unregister(&bq20z75_device->power_supply); + + cancel_delayed_work_sync(&bq20z75_device->work); + kfree(bq20z75_device); bq20z75_device = NULL; @@ -661,6 +743,9 @@ static int bq20z75_suspend(struct i2c_client *client, struct bq20z75_info *bq20z75_device = i2c_get_clientdata(client); s32 ret; + if (bq20z75_device->poll_time > 0) + cancel_delayed_work_sync(&bq20z75_device->work); + /* write to manufacturer access with sleep command */ ret = bq20z75_write_word_data(client, bq20z75_data[REG_MANUFACTURER_DATA].addr, diff --git a/include/linux/power/bq20z75.h b/include/linux/power/bq20z75.h index b0843b6..1398eb0 100644 --- a/include/linux/power/bq20z75.h +++ b/include/linux/power/bq20z75.h @@ -29,11 +29,14 @@ * @battery_detect: GPIO which is used to detect battery presence * @battery_detect_present: gpio state when battery is present (0 / 1) * @i2c_retry_count: # of times to retry on i2c IO failure + * @poll_retry_count: # of times to retry looking for new status after + * external change notification */ struct bq20z75_platform_data { int battery_detect; int battery_detect_present; int i2c_retry_count; + int poll_retry_count; }; #endif -- 1.7.5.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/