From 17c6d3979e5bbff1de36a4e89015fa09ac495d27 Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Thu, 8 Sep 2016 19:10:00 -0700 Subject: sbs-battery: make writes to ManufacturerAccess optional According to the Smart Battery Data Specification, the use of ManufacturerAcess (register 0x0) is implementation-defined. It appears that some batteries use writes to this register in order to implement certain functionality, but others may simply NAK all writes to it. As a result, write failures to ManufacturerAccess should not be used as an indicator of battery presence, nor as a failure to enter sleep mode. The failed write access was seen with SANYO AP13J3K. Cc: Brian Norris Signed-off-by: Guenter Roeck Signed-off-by: Sebastian Reichel --- drivers/power/supply/sbs-battery.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-) (limited to 'drivers/power') diff --git a/drivers/power/supply/sbs-battery.c b/drivers/power/supply/sbs-battery.c index 248a5dd75e22..bc7acdf84d60 100644 --- a/drivers/power/supply/sbs-battery.c +++ b/drivers/power/supply/sbs-battery.c @@ -317,21 +317,22 @@ static int sbs_get_battery_presence_and_health( return ret; } - /* Write to ManufacturerAccess with - * ManufacturerAccess command and then - * read the status */ - ret = sbs_write_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr, - MANUFACTURER_ACCESS_STATUS); + /* + * Write to ManufacturerAccess with ManufacturerAccess command + * and then read the status. Do not check for error on the write + * since not all batteries implement write access to this command, + * while others mandate it. + */ + sbs_write_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr, + MANUFACTURER_ACCESS_STATUS); + + ret = sbs_read_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr); if (ret < 0) { if (psp == POWER_SUPPLY_PROP_PRESENT) val->intval = 0; /* battery removed */ return ret; } - ret = sbs_read_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr); - if (ret < 0) - return ret; - if (ret < sbs_data[REG_MANUFACTURER_DATA].min_value || ret > sbs_data[REG_MANUFACTURER_DATA].max_value) { val->intval = 0; @@ -882,16 +883,16 @@ static int sbs_suspend(struct device *dev) { struct i2c_client *client = to_i2c_client(dev); struct sbs_info *chip = i2c_get_clientdata(client); - s32 ret; if (chip->poll_time > 0) cancel_delayed_work_sync(&chip->work); - /* write to manufacturer access with sleep command */ - ret = sbs_write_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr, + /* + * Write to manufacturer access with sleep command. + * Support is manufacturer dependend, so ignore errors. + */ + sbs_write_word_data(client, sbs_data[REG_MANUFACTURER_DATA].addr, MANUFACTURER_ACCESS_SLEEP); - if (chip->is_present && ret < 0) - return ret; return 0; } -- cgit v1.2.3