| Message ID | 20210816165245.40416-2-bruno.meneguele@smartgreen.net |
|---|---|
| State | New |
| Headers | show |
| Series | add Watchdog Timer delay support for BQ24735 | expand |
Hi, On Mon, Aug 16, 2021 at 01:52:44PM -0300, Bruno Meneguele wrote: > The BQ24735 charger allows the user to set the watchdog timer delay between > two consecutives ChargeCurrent or ChargeVoltage command writes, if the IC > doesn't receive any command before the timeout happens, the charge is turned > off. > > This patch adds the support to the user to change the default/POR value with > four discrete values: > > 0 - disabled > 1 - enabled, 44 sec > 2 - enabled, 88 sec > 3 - enabled, 175 sec (default at POR) > > These are the options supported in the ChargeOptions register bits 13&14. > > Also, this patch make one additional check when poll-interval is set by the > user: if the interval set is greater than the WDT timeout it'll fail during > the probe stage, preventing the user to set non-compatible values between > the two options. > > Signed-off-by: Bruno Meneguele <bruno.meneguele@smartgreen.net> > --- > Changelog: > v3 - check wdt_timeout for the maximum and minimum available values > > drivers/power/supply/bq24735-charger.c | 54 ++++++++++++++++++++++++++ > include/linux/power/bq24735-charger.h | 1 + > 2 files changed, 55 insertions(+) > > diff --git a/drivers/power/supply/bq24735-charger.c b/drivers/power/supply/bq24735-charger.c > index 3ce36d09c017..7e8d0c23df9a 100644 > --- a/drivers/power/supply/bq24735-charger.c > +++ b/drivers/power/supply/bq24735-charger.c > @@ -45,6 +45,8 @@ > /* ChargeOptions bits of interest */ > #define BQ24735_CHARGE_OPT_CHG_DISABLE (1 << 0) > #define BQ24735_CHARGE_OPT_AC_PRESENT (1 << 4) > +#define BQ24735_CHARGE_OPT_WDT_OFFSET 13 > +#define BQ24735_CHARGE_OPT_WDT (3 << BQ24735_CHARGE_OPT_WDT_OFFSET) > > struct bq24735 { > struct power_supply *charger; > @@ -156,6 +158,20 @@ static int bq24735_config_charger(struct bq24735 *charger) > } > } > > + if (pdata->wdt_timeout >= 0 && pdata->wdt_timeout <= 3) { wdt_timeout is unsigned and can't be smaller than 0. > + value = pdata->wdt_timeout; > + > + ret = bq24735_update_word(charger->client, BQ24735_CHARGE_OPT, > + BQ24735_CHARGE_OPT_WDT, > + (value << BQ24735_CHARGE_OPT_WDT_OFFSET)); > + if (ret < 0) { > + dev_err(&charger->client->dev, > + "Failed to write watchdog timer: %d\n", > + ret); > + return ret; > + } > + } > + > return 0; > } > > @@ -347,6 +363,23 @@ static struct bq24735_platform *bq24735_parse_dt_data(struct i2c_client *client) > if (!ret) > pdata->input_current = val; > > + ret = of_property_read_u32(np, "ti,wdt-timeout", &val); > + if (!ret) { > + if (val >= 0 && val <= 3) { wdt_timeout is unsigned and can't be smaller than 0. > + pdata->wdt_timeout = val; > + } else { > + dev_warn(&client->dev, > + "Invalid value for ti,wdt-timeout: %d", > + val); > + } > + } else { > + /* Since 0 is a valid value (disabled), set something > + * greater than the maximum limit accepted from the user to > + * represent the "no change" state. */ > + pdata->wdt_timeout = 4; > + } > + > + > pdata->ext_control = of_property_read_bool(np, "ti,external-control"); > > return pdata; > @@ -476,6 +509,27 @@ static int bq24735_charger_probe(struct i2c_client *client, > return 0; > if (!charger->poll_interval) > return 0; > + if (charger->pdata->wdt_timeout > 0) { > + int wdt_ms; > + > + switch (charger->pdata->wdt_timeout) { > + case 1: > + wdt_ms = 44000; > + break; > + case 2: > + wdt_ms = 88000; > + break; > + case 3: > + wdt_ms = 175000; > + break; > + } wdt_ms is not initialized when wdt_timeout is not 1-3 resulting in undefined behaviour. Also please create constants for the magic numbers, e.g. #define BQ24735_WDT_OFF 0 #define BQ24735_WDT_44_SEC 1 #define BQ24735_WDT_88_SEC 2 #define BQ24735_WDT_175_SEC 3 #define BQ24735_WDT_INVALID 4 and use them throughout the code. -- Sebastian > + > + if (charger->poll_interval > wdt_ms) { > + dev_err(&client->dev, > + "Poll interval greater than WDT timeout\n"); > + return -EINVAL; > + } > + } > > ret = devm_delayed_work_autocancel(&client->dev, &charger->poll, > bq24735_poll); > diff --git a/include/linux/power/bq24735-charger.h b/include/linux/power/bq24735-charger.h > index 321dd009ce66..ce5a030ca111 100644 > --- a/include/linux/power/bq24735-charger.h > +++ b/include/linux/power/bq24735-charger.h > @@ -12,6 +12,7 @@ struct bq24735_platform { > uint32_t charge_current; > uint32_t charge_voltage; > uint32_t input_current; > + uint32_t wdt_timeout; > > const char *name; > > -- > 2.31.1 >
diff --git a/drivers/power/supply/bq24735-charger.c b/drivers/power/supply/bq24735-charger.c index 3ce36d09c017..7e8d0c23df9a 100644 --- a/drivers/power/supply/bq24735-charger.c +++ b/drivers/power/supply/bq24735-charger.c @@ -45,6 +45,8 @@ /* ChargeOptions bits of interest */ #define BQ24735_CHARGE_OPT_CHG_DISABLE (1 << 0) #define BQ24735_CHARGE_OPT_AC_PRESENT (1 << 4) +#define BQ24735_CHARGE_OPT_WDT_OFFSET 13 +#define BQ24735_CHARGE_OPT_WDT (3 << BQ24735_CHARGE_OPT_WDT_OFFSET) struct bq24735 { struct power_supply *charger; @@ -156,6 +158,20 @@ static int bq24735_config_charger(struct bq24735 *charger) } } + if (pdata->wdt_timeout >= 0 && pdata->wdt_timeout <= 3) { + value = pdata->wdt_timeout; + + ret = bq24735_update_word(charger->client, BQ24735_CHARGE_OPT, + BQ24735_CHARGE_OPT_WDT, + (value << BQ24735_CHARGE_OPT_WDT_OFFSET)); + if (ret < 0) { + dev_err(&charger->client->dev, + "Failed to write watchdog timer: %d\n", + ret); + return ret; + } + } + return 0; } @@ -347,6 +363,23 @@ static struct bq24735_platform *bq24735_parse_dt_data(struct i2c_client *client) if (!ret) pdata->input_current = val; + ret = of_property_read_u32(np, "ti,wdt-timeout", &val); + if (!ret) { + if (val >= 0 && val <= 3) { + pdata->wdt_timeout = val; + } else { + dev_warn(&client->dev, + "Invalid value for ti,wdt-timeout: %d", + val); + } + } else { + /* Since 0 is a valid value (disabled), set something + * greater than the maximum limit accepted from the user to + * represent the "no change" state. */ + pdata->wdt_timeout = 4; + } + + pdata->ext_control = of_property_read_bool(np, "ti,external-control"); return pdata; @@ -476,6 +509,27 @@ static int bq24735_charger_probe(struct i2c_client *client, return 0; if (!charger->poll_interval) return 0; + if (charger->pdata->wdt_timeout > 0) { + int wdt_ms; + + switch (charger->pdata->wdt_timeout) { + case 1: + wdt_ms = 44000; + break; + case 2: + wdt_ms = 88000; + break; + case 3: + wdt_ms = 175000; + break; + } + + if (charger->poll_interval > wdt_ms) { + dev_err(&client->dev, + "Poll interval greater than WDT timeout\n"); + return -EINVAL; + } + } ret = devm_delayed_work_autocancel(&client->dev, &charger->poll, bq24735_poll); diff --git a/include/linux/power/bq24735-charger.h b/include/linux/power/bq24735-charger.h index 321dd009ce66..ce5a030ca111 100644 --- a/include/linux/power/bq24735-charger.h +++ b/include/linux/power/bq24735-charger.h @@ -12,6 +12,7 @@ struct bq24735_platform { uint32_t charge_current; uint32_t charge_voltage; uint32_t input_current; + uint32_t wdt_timeout; const char *name;
The BQ24735 charger allows the user to set the watchdog timer delay between two consecutives ChargeCurrent or ChargeVoltage command writes, if the IC doesn't receive any command before the timeout happens, the charge is turned off. This patch adds the support to the user to change the default/POR value with four discrete values: 0 - disabled 1 - enabled, 44 sec 2 - enabled, 88 sec 3 - enabled, 175 sec (default at POR) These are the options supported in the ChargeOptions register bits 13&14. Also, this patch make one additional check when poll-interval is set by the user: if the interval set is greater than the WDT timeout it'll fail during the probe stage, preventing the user to set non-compatible values between the two options. Signed-off-by: Bruno Meneguele <bruno.meneguele@smartgreen.net> --- Changelog: v3 - check wdt_timeout for the maximum and minimum available values drivers/power/supply/bq24735-charger.c | 54 ++++++++++++++++++++++++++ include/linux/power/bq24735-charger.h | 1 + 2 files changed, 55 insertions(+)