diff mbox series

[05/11,v2] power: supply: ab8500_fg: Break out load compensated voltage

Message ID 20220129004925.639684-6-linus.walleij@linaro.org
State Accepted
Commit 673b50322bb6e31f0e917eeb321648092528635a
Headers show
Series AB8500 charging fixes | expand

Commit Message

Linus Walleij Jan. 29, 2022, 12:49 a.m. UTC 
Break out the part of the function providing the load compensated
capacity that provides the load compensated voltage and use
that to get the load compensated capacity.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
ChangeLog v1->v2:
- Fix patch ordering issue: I was using a uv argument to
  ab8500_fg_battery_resistance() however that refactoring is
  later on in the series. Fixed now.
---
 drivers/power/supply/ab8500_fg.c | 50 ++++++++++++++++++++------------
 1 file changed, 32 insertions(+), 18 deletions(-)

Comments

Sebastian Reichel Feb. 11, 2022, 7:32 p.m. UTC | #1 
Hi,

On Sat, Jan 29, 2022 at 01:49:19AM +0100, Linus Walleij wrote:
> Break out the part of the function providing the load compensated
> capacity that provides the load compensated voltage and use
> that to get the load compensated capacity.
> 
> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
> ---
> ChangeLog v1->v2:
> - Fix patch ordering issue: I was using a uv argument to
>   ab8500_fg_battery_resistance() however that refactoring is
>   later on in the series. Fixed now.
> ---
>  drivers/power/supply/ab8500_fg.c | 50 ++++++++++++++++++++------------
>  1 file changed, 32 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/power/supply/ab8500_fg.c b/drivers/power/supply/ab8500_fg.c
> index 29896f09fd17..1797518c4b0e 100644
> --- a/drivers/power/supply/ab8500_fg.c
> +++ b/drivers/power/supply/ab8500_fg.c
> @@ -909,18 +909,20 @@ static int ab8500_fg_battery_resistance(struct ab8500_fg *di)
>  }
>  
>  /**
> - * ab8500_fg_load_comp_volt_to_capacity() - Load compensated voltage based capacity
> + * ab8500_load_comp_fg_bat_voltage() - get load compensated battery voltage
>   * @di:		pointer to the ab8500_fg structure
>   *
> - * Returns battery capacity based on battery voltage that is load compensated
> - * for the voltage drop
> + * Returns compensated battery voltage (on success) else error code.
> + * If always is specified, we always return a voltage but it may be
> + * uncompensated.

This documents the always parameter, which is only introduced in the
next patch :) Since I found nothing else I merged the patchset anyways.

I also noticed that 'always' is always true at the end of this
patchset (and assumed it will be used in a future patchset).

Greetings,

-- Sebastian
diff mbox series

Patch

diff --git a/drivers/power/supply/ab8500_fg.c b/drivers/power/supply/ab8500_fg.c
index 29896f09fd17..1797518c4b0e 100644
--- a/drivers/power/supply/ab8500_fg.c
+++ b/drivers/power/supply/ab8500_fg.c
@@ -909,18 +909,20 @@  static int ab8500_fg_battery_resistance(struct ab8500_fg *di)
 }
 
 /**
- * ab8500_fg_load_comp_volt_to_capacity() - Load compensated voltage based capacity
+ * ab8500_load_comp_fg_bat_voltage() - get load compensated battery voltage
  * @di:		pointer to the ab8500_fg structure
  *
- * Returns battery capacity based on battery voltage that is load compensated
- * for the voltage drop
+ * Returns compensated battery voltage (on success) else error code.
+ * If always is specified, we always return a voltage but it may be
+ * uncompensated.
  */
-static int ab8500_fg_load_comp_volt_to_capacity(struct ab8500_fg *di)
+static int ab8500_load_comp_fg_bat_voltage(struct ab8500_fg *di)
 {
-	int vbat_comp_uv, res;
 	int i = 0;
 	int vbat_uv = 0;
+	int rcomp;
 
+	/* Average the instant current to get a stable current measurement */
 	ab8500_fg_inst_curr_start(di);
 
 	do {
@@ -932,25 +934,37 @@  static int ab8500_fg_load_comp_volt_to_capacity(struct ab8500_fg *di)
 
 	if (i > WAIT_FOR_INST_CURRENT_MAX) {
 		dev_err(di->dev,
-			"TIMEOUT: return capacity based on uncompensated measurement of VBAT\n");
-		goto calc_cap;
+			"TIMEOUT: return uncompensated measurement of VBAT\n");
+		di->vbat_uv = vbat_uv / i;
+		return di->vbat_uv;
 	}
 
 	ab8500_fg_inst_curr_finalize(di, &di->inst_curr_ua);
 
-calc_cap:
-	di->vbat_uv = vbat_uv / i;
-	res = ab8500_fg_battery_resistance(di);
+	vbat_uv = vbat_uv / i;
 
-	/*
-	 * Use Ohms law to get the load compensated voltage.
-	 * Divide by 1000 to get from milliohms to ohms.
-	 */
-	vbat_comp_uv = di->vbat_uv - (di->inst_curr_ua * res) / 1000;
+	/* Next we apply voltage compensation from internal resistance */
+	rcomp = ab8500_fg_battery_resistance(di);
+	vbat_uv = vbat_uv - (di->inst_curr_ua * rcomp) / 1000;
+
+	/* Always keep this state at latest measurement */
+	di->vbat_uv = vbat_uv;
+
+	return vbat_uv;
+}
+
+/**
+ * ab8500_fg_load_comp_volt_to_capacity() - Load compensated voltage based capacity
+ * @di:		pointer to the ab8500_fg structure
+ *
+ * Returns battery capacity based on battery voltage that is load compensated
+ * for the voltage drop
+ */
+static int ab8500_fg_load_comp_volt_to_capacity(struct ab8500_fg *di)
+{
+	int vbat_comp_uv;
 
-	dev_dbg(di->dev, "%s Measured Vbat: %d uV,Compensated Vbat %d uV, "
-		"R: %d mOhm, Current: %d uA Vbat Samples: %d\n",
-		__func__, di->vbat_uv, vbat_comp_uv, res, di->inst_curr_ua, i);
+	vbat_comp_uv = ab8500_load_comp_fg_bat_voltage(di);
 
 	return ab8500_fg_volt_to_capacity(di, vbat_comp_uv);
 }