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Message-ID: <CAO-hwJJPDQ0JcLTOca0E3oKQfYV6BHbm4u4xcx4rYoVcC28Ctw@mail.gmail.com>
Date: Fri, 23 Aug 2019 18:15:13 +0200
From: Benjamin Tissoires <benjamin.tissoires@...hat.com>
To: Pedro Vanzella <pedro@...rovanzella.com>
Cc: "open list:HID CORE LAYER" <linux-input@...r.kernel.org>,
Filipe Laíns <lains@...hlinux.org>,
Jiri Kosina <jikos@...nel.org>,
lkml <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v4] hid-logitech-hidpp: read battery voltage from newer devices
Hi Pedro,
On Fri, Aug 23, 2019 at 5:51 PM Pedro Vanzella <pedro@...rovanzella.com> wrote:
>
> Newer Logitech mice report their battery voltage through feature 0x1001
> instead of the battery levels through feature 0x1000.
>
> When the device is brought up and we try to query the battery, figure
> out if it supports the old or the new feature. If it supports the new
> feature, record the feature index and read the battery voltage and
> its status.
>
> If everything went correctly, record the fact that we're capable
> of querying battery voltage.
>
> Note that the protocol only gives us the current voltage in millivolts.
>
> Like we do for other ways of interacting with the battery for other
> devices, refresh the battery status and notify the power supply
> subsystem of the changes in voltage and status.
>
> Signed-off-by: Pedro Vanzella <pedro@...rovanzella.com>
I still have comments, please see inline:
> ---
> drivers/hid/hid-logitech-hidpp.c | 140 ++++++++++++++++++++++++++++++-
> 1 file changed, 138 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
> index 0179f7ed77e5..5c9c3133d2ae 100644
> --- a/drivers/hid/hid-logitech-hidpp.c
> +++ b/drivers/hid/hid-logitech-hidpp.c
> @@ -87,6 +87,7 @@ MODULE_PARM_DESC(disable_tap_to_click,
> #define HIDPP_CAPABILITY_HIDPP20_BATTERY BIT(1)
> #define HIDPP_CAPABILITY_BATTERY_MILEAGE BIT(2)
> #define HIDPP_CAPABILITY_BATTERY_LEVEL_STATUS BIT(3)
> +#define HIDPP_CAPABILITY_BATTERY_VOLTAGE BIT(4)
>
> /*
> * There are two hidpp protocols in use, the first version hidpp10 is known
> @@ -135,12 +136,14 @@ struct hidpp_report {
> struct hidpp_battery {
> u8 feature_index;
> u8 solar_feature_index;
> + u8 voltage_feature_index;
> struct power_supply_desc desc;
> struct power_supply *ps;
> char name[64];
> int status;
> int capacity;
> int level;
> + int voltage; /* in millivolts */
> bool online;
> };
>
> @@ -1219,6 +1222,122 @@ static int hidpp20_battery_event(struct hidpp_device *hidpp,
> return 0;
> }
>
> +/* -------------------------------------------------------------------------- */
> +/* 0x1001: Battery voltage */
> +/* -------------------------------------------------------------------------- */
> +
> +#define HIDPP_PAGE_BATTERY_VOLTAGE 0x1001
> +
> +#define CMD_BATTERY_VOLTAGE_GET_BATTERY_VOLTAGE 0x00
> +
> +static int hidpp20_battery_map_status_voltage(u8 data[3], int *voltage)
> +{
> + int status;
> +
> + switch (data[2]) {
> + case 0x00: /* discharging */
> + status = POWER_SUPPLY_STATUS_DISCHARGING;
> + break;
> + case 0x10: /* wireless charging */
> + case 0x80: /* charging */
> + status = POWER_SUPPLY_STATUS_CHARGING;
> + break;
> + case 0x81: /* fully charged */
> + status = POWER_SUPPLY_STATUS_FULL;
> + break;
> + default:
> + status = POWER_SUPPLY_STATUS_NOT_CHARGING;
> + }
> +
> + *voltage = (data[0] << 8) + data[1];
If I am not wrong, you can use get_unaligned_be16 here instead
> +
> + return status;
> +}
> +
> +static int hidpp20_battery_get_battery_voltage(struct hidpp_device *hidpp,
> + u8 feature_index,
> + int *status, int *voltage)
> +{
> + struct hidpp_report response;
> + int ret;
> + u8 *params = (u8 *)response.fap.params;
> +
> + ret = hidpp_send_fap_command_sync(hidpp, feature_index,
> + CMD_BATTERY_VOLTAGE_GET_BATTERY_VOLTAGE,
> + NULL, 0, &response);
> +
> + if (ret > 0) {
> + hid_err(hidpp->hid_dev, "%s: received protocol error 0x%02x\n",
> + __func__, ret);
> + return -EPROTO;
> + }
> + if (ret)
> + return ret;
> +
> + hidpp->capabilities |= HIDPP_CAPABILITY_BATTERY_VOLTAGE;
> +
> + *status = hidpp20_battery_map_status_voltage(params, voltage);
> +
> + return 0;
> +}
> +
> +static int hidpp20_query_battery_voltage_info(struct hidpp_device *hidpp)
> +{
> + u8 feature_type;
> + int ret;
> + int status, voltage;
> +
> + if (hidpp->battery.voltage_feature_index == 0xff) {
> + ret = hidpp_root_get_feature(hidpp, HIDPP_PAGE_BATTERY_VOLTAGE,
> + &hidpp->battery.voltage_feature_index,
> + &feature_type);
> + if (ret)
> + return ret;
> + }
> +
> + ret = hidpp20_battery_get_battery_voltage(hidpp,
> + hidpp->battery.voltage_feature_index,
> + &status, &voltage);
> +
> + if (ret)
> + return ret;
> +
> + hidpp->battery.status = status;
> + hidpp->battery.voltage = voltage;
> + hidpp->battery.online = status != POWER_SUPPLY_STATUS_NOT_CHARGING;
> +
> + return 0;
> +}
> +
> +static int hidpp20_battery_voltage_event(struct hidpp_device *hidpp,
> + u8 *data, int size)
> +{
> + struct hidpp_report *report = (struct hidpp_report *)data;
> + int status, voltage;
> + bool changed;
> +
> + if (report->fap.feature_index != hidpp->battery.voltage_feature_index ||
> + report->fap.funcindex_clientid !=
> + EVENT_BATTERY_LEVEL_STATUS_BROADCAST)
this should probably be defined in 0x1001 as
EVENT_BATTERY_VOLTAGE_STATUS_BROADCAST
> + return 0;
> +
> + status = hidpp20_battery_map_status_voltage(report->fap.params,
> + &voltage);
> +
> + hidpp->battery.online = status != POWER_SUPPLY_STATUS_NOT_CHARGING;
> +
> + changed = voltage != hidpp->battery.voltage ||
> + status != hidpp->battery.status;
> +
> + if (changed) {
There is no point in using an extra `changed` variable here, just
unwind the boolean operation above here.
> + hidpp->battery.voltage = voltage;
> + hidpp->battery.status = status;
> + if (hidpp->battery.ps)
> + power_supply_changed(hidpp->battery.ps);
> + }
> + return 0;
> +}
> +
> static enum power_supply_property hidpp_battery_props[] = {
> POWER_SUPPLY_PROP_ONLINE,
> POWER_SUPPLY_PROP_STATUS,
> @@ -1228,6 +1347,7 @@ static enum power_supply_property hidpp_battery_props[] = {
> POWER_SUPPLY_PROP_SERIAL_NUMBER,
> 0, /* placeholder for POWER_SUPPLY_PROP_CAPACITY, */
> 0, /* placeholder for POWER_SUPPLY_PROP_CAPACITY_LEVEL, */
> + 0, /* placeholder for POWER_SUPPLY_PROP_VOLTAGE_NOW, */
> };
>
> static int hidpp_battery_get_property(struct power_supply *psy,
> @@ -1265,6 +1385,9 @@ static int hidpp_battery_get_property(struct power_supply *psy,
> case POWER_SUPPLY_PROP_SERIAL_NUMBER:
> val->strval = hidpp->hid_dev->uniq;
> break;
> + case POWER_SUPPLY_PROP_VOLTAGE_NOW:
> + val->intval = hidpp->battery.voltage;
> + break;
> default:
> ret = -EINVAL;
> break;
> @@ -3083,6 +3206,9 @@ static int hidpp_raw_hidpp_event(struct hidpp_device *hidpp, u8 *data,
> ret = hidpp_solar_battery_event(hidpp, data, size);
> if (ret != 0)
> return ret;
> + ret = hidpp20_battery_voltage_event(hidpp, data, size);
> + if (ret != 0)
> + return ret;
> }
>
> if (hidpp->capabilities & HIDPP_CAPABILITY_HIDPP10_BATTERY) {
> @@ -3204,12 +3330,16 @@ static int hidpp_initialize_battery(struct hidpp_device *hidpp)
>
> hidpp->battery.feature_index = 0xff;
> hidpp->battery.solar_feature_index = 0xff;
> + hidpp->battery.voltage_feature_index = 0xff;
>
> if (hidpp->protocol_major >= 2) {
> if (hidpp->quirks & HIDPP_QUIRK_CLASS_K750)
> ret = hidpp_solar_request_battery_event(hidpp);
> - else
> + else {
> ret = hidpp20_query_battery_info(hidpp);
> + if (ret)
> + ret = hidpp20_query_battery_voltage_info(hidpp);
> + }
we should probably do the other way around: first test
hidpp20_query_battery_voltage_info and then go for the generic one, so
that the error returned will be the one from the most common feature,
and you will keep existing behaviour.
>
> if (ret)
> return ret;
> @@ -3234,7 +3364,7 @@ static int hidpp_initialize_battery(struct hidpp_device *hidpp)
> if (!battery_props)
> return -ENOMEM;
>
> - num_battery_props = ARRAY_SIZE(hidpp_battery_props) - 2;
> + num_battery_props = ARRAY_SIZE(hidpp_battery_props) - 3;
>
> if (hidpp->capabilities & HIDPP_CAPABILITY_BATTERY_MILEAGE)
> battery_props[num_battery_props++] =
> @@ -3244,6 +3374,10 @@ static int hidpp_initialize_battery(struct hidpp_device *hidpp)
> battery_props[num_battery_props++] =
> POWER_SUPPLY_PROP_CAPACITY_LEVEL;
>
> + if (hidpp->capabilities & HIDPP_CAPABILITY_BATTERY_VOLTAGE)
> + battery_props[num_battery_props++] =
> + POWER_SUPPLY_PROP_VOLTAGE_NOW;
> +
> battery = &hidpp->battery;
>
> n = atomic_inc_return(&battery_no) - 1;
> @@ -3408,6 +3542,8 @@ static void hidpp_connect_event(struct hidpp_device *hidpp)
> hidpp10_query_battery_status(hidpp);
> } else if (hidpp->capabilities & HIDPP_CAPABILITY_HIDPP20_BATTERY) {
> hidpp20_query_battery_info(hidpp);
> + if (hidpp->capabilities & HIDPP_CAPABILITY_BATTERY_VOLTAGE)
> + hidpp20_query_battery_voltage_info(hidpp);
I'd put the test above `hidpp20_query_battery_info(hidpp);` and would
add an else statement to fetch the battery info
> }
> if (hidpp->battery.ps)
> power_supply_changed(hidpp->battery.ps);
> --
> 2.23.0
>
Cheers,
Benjamin
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