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From: Andy S. <and...@gm...> - 2018-01-01 10:24:46
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On Sun, Dec 31, 2017 at 4:17 PM, Ognjen Galic <smc...@gm...> wrote:
> thinkpad_acpi registers two new attributes for each battery:
>
> 1) Charge start threshold
> /sys/class/power_supply/BATN/charge_start_threshold
>
> Valid values are [0, 99]. A value of 0 turns off the
> start threshold wear control.
>
> 2) Charge stop threshold
> /sys/class/power_supply/BATN/charge_stop_threshold
>
> Valid values are [1, 100]. A value of 100 turns off
> the stop threshold wear control. This must be
> configured first.
>
> This patch depends on the following patches:
>
> "battery: Add the battery hooking API"
Since this is series, no need to put above into changelog.
AFAICS it's not going to be backported either.
> +/**
> + * This evaluates a ACPI method call specific to the battery
> + * ACPI extension. The specifics are that an error is marked
> + * in the 32rd bit of the response, so we just check that here.
> + *
> + * Returns 0 on success
> + */
> +static int tpacpi_battery_acpi_eval(char *method, int *ret, int param)
> +{
One problem and one trick you may do.
A problem: you return ACPI status as int. We have special type for
that. So, be consistent with it.
Looking to acpi_evalf() which is private to the module, I think you
need to get rid of ACPI return codes here.
A trick: since you are using only least significant byte of the
response, you can declare it as u8 *value (yeah, ret is not best name
here I think).
So, something like
..._eval(..., u8 *value, ...)
{
int response;
if (!..._evalf(..., &response, ...)) {
...
> + if (!acpi_evalf(hkey_handle, ret, method, "dd", param)) {
> + acpi_handle_err(hkey_handle, "%s: evaluate failed", method);
> + return AE_ERROR;
> + }
> +
> + if (*ret & METHOD_ERR) {
if (response & ...) {
> + acpi_handle_err(hkey_handle,
> + "%s evaluated but flagged as error", method);
> + return AE_ERROR;
> + }
*value = response;
> +
> + return AE_OK;
> +}
> +static int tpacpi_battery_get(int what, int battery, int *ret)
> +{
> + switch (what) {
> +
> + case THRESHOLD_START:
> +
> + if (tpacpi_battery_acpi_eval(GET_START, ret, battery))
> + return -ENODEV;
> +
> + /* The value is in the low 8 bits of the response */
> + *ret = *ret & 0xFF;
So, this will gone with a trick above.
> + return 0;
> +
> + case THRESHOLD_STOP:
> +
> + if (tpacpi_battery_acpi_eval(GET_STOP, ret, battery))
> + return -ENODEV;
> +
> + /* Value is in lower 8 bits */
> + *ret = *ret & 0xFF;
Ditto.
> +
> + /*
> + * On the stop value, if we return 0 that
> + * does not make any sense. 0 means Default, which
> + * means that charging stops at 100%, so we return
> + * that.
> + */
> + if (*ret == 0)
> + *ret = 100;
> +
> + return 0;
> +
> + default:
> + pr_crit("wrong parameter: %d", what);
> + return -EINVAL;
> + }
> +
> +}
> +static int tpacpi_battery_probe(int battery)
> +{
> + int ret = 0;
> +
> + memset(&battery_info, 0, sizeof(struct tpacpi_battery_driver_data));
> +
> + /*
> + * 1) Get the current start threshold
> + * 2) Check for support
> + * 3) Get the current stop threshold
> + * 4) Check for support
> + */
> +
> + if (acpi_has_method(hkey_handle, GET_START)) {
> +
> + if (tpacpi_battery_acpi_eval(GET_START, &ret, battery)) {
> + pr_err("Error probing battery %d\n", battery);
> + return -ENODEV;
> + }
> +
> + /* Individual addressing is in bit 9 */
> + if (ret & BIT(9))
> + battery_info.individual_addressing = true;
> +
> + /* Support is marked in bit 8 */
> + if (ret & BIT(8))
> + battery_info.batteries[battery].start_support = 1;
> + else
> + return -ENODEV;
> +
> + if (tpacpi_battery_get(THRESHOLD_START, battery,
> + &battery_info.batteries[battery].charge_start)) {
> + pr_err("Error probing battery %d\n", battery);
> + return -ENODEV;
> + }
> +
Please, get rid of all useless empty lines like this one, or above (in
between of two if:s).
> + }
> +/* General helper functions */
> +
> +static int tpacpi_battery_get_id(const char *battery_name)
> +{
> +
> + if (strcmp(battery_name, "BAT0") == 0)
> + return BAT_PRIMARY;
> + if (strcmp(battery_name, "BAT1") == 0)
> + return BAT_SECONDARY;
> +
> + /*
> + * If for some reason the battery is not BAT0 nor is it
> + * BAT1, we will assume it's the default, first battery,
> + * AKA primary.
> + */
> + pr_warn("unknown battery %s, assuming primary", battery_name);
> + return BAT_PRIMARY;
> +}
> +
> +/* sysfs interface */
> +
> +static ssize_t tpacpi_battery_store(int what,
> + struct device *dev,
> + const char *buf, size_t count)
> +{
> + struct power_supply *supply = to_power_supply(dev);
> + unsigned long value;
> + int battery, errno;
> + errno = kstrtoul(buf, 10, &value);
> +
Dont' split lines like these where one returns some error code
followed by conditional check.
> + if (errno)
> + return errno;
Besides, errno is a bad name, please consider what is used elsewhere
in this module (rc, ret, rval, ...?).
--
With Best Regards,
Andy Shevchenko
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