power: qpnp-fg-gen3: Add WA for oscillator drift on PM660

It is observed that on certain foundry devices, frequency of the
standby oscillator drifts with die temperature. Compensate
for this by correcting the FG time-base based on die temperature.

Change-Id: I0de19b9c342bf50568502b4de96897e159a8e143
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>

2 files changed, 82 insertions, 5 deletions

diff --git a/drivers/power/supply/qcom/fg-core.h b/drivers/power/supply/qcom/fg-core.h
index 316313ff6408..f35864183635 100644
--- a/drivers/power/supply/qcom/fg-core.h
+++ b/drivers/power/supply/qcom/fg-core.h
@@ -128,11 +128,6 @@ enum fg_irq_index {
 	FG_IRQ_MAX,
 };
 
-/* WA flags */
-enum {
-	DELTA_SOC_IRQ_WA = BIT(0),
-};
-
 /*
  * List of FG_SRAM parameters. Please add a parameter only if it is an entry
  * that will be used either to configure an entity (e.g. termination current)
@@ -152,6 +147,7 @@ enum fg_sram_param_id {
 	FG_SRAM_CC_SOC,
 	FG_SRAM_CC_SOC_SW,
 	FG_SRAM_ACT_BATT_CAP,
+	FG_SRAM_TIMEBASE,
 	/* Entries below here are configurable during initialization */
 	FG_SRAM_CUTOFF_VOLT,
 	FG_SRAM_EMPTY_VOLT,
@@ -210,6 +206,7 @@ struct fg_alg_flag {
 
 enum wa_flags {
 	PMI8998_V1_REV_WA = BIT(0),
+	PM660_TSMC_OSC_WA = BIT(1),
 };
 
 enum slope_limit_status {
@@ -322,6 +319,23 @@ static const struct fg_pt fg_ln_table[] = {
 	{ 128000,	4852 },
 };
 
+/* each tuple is - <temperature in degC, Timebase> */
+static const struct fg_pt fg_tsmc_osc_table[] = {
+	{ -20,		395064 },
+	{ -10,		398114 },
+	{   0,		401669 },
+	{  10,		404641 },
+	{  20,		408856 },
+	{  25,		412449 },
+	{  30,		416532 },
+	{  40,		420289 },
+	{  50,		425020 },
+	{  60,		430160 },
+	{  70,		434175 },
+	{  80,		439475 },
+	{  90,		444992 },
+};
+
 struct fg_chip {
 	struct device		*dev;
 	struct pmic_revid_data	*pmic_rev_id;
@@ -333,6 +347,7 @@ struct fg_chip {
 	struct power_supply	*dc_psy;
 	struct power_supply	*parallel_psy;
 	struct iio_channel	*batt_id_chan;
+	struct iio_channel	*die_temp_chan;
 	struct fg_memif		*sram;
 	struct fg_irq_info	*irqs;
 	struct votable		*awake_votable;
diff --git a/drivers/power/supply/qcom/qpnp-fg-gen3.c b/drivers/power/supply/qcom/qpnp-fg-gen3.c
index 2e9425040f72..8cc67b4e6ff2 100644
--- a/drivers/power/supply/qcom/qpnp-fg-gen3.c
+++ b/drivers/power/supply/qcom/qpnp-fg-gen3.c
@@ -47,6 +47,7 @@
 #define ESR_UPD_TIGHT_LOW_TEMP_OFFSET	2
 #define ESR_UPD_BROAD_LOW_TEMP_OFFSET	3
 #define KI_COEFF_MED_DISCHG_WORD	9
+#define TIMEBASE_OFFSET			1
 #define KI_COEFF_MED_DISCHG_OFFSET	3
 #define KI_COEFF_HI_DISCHG_WORD		10
 #define KI_COEFF_HI_DISCHG_OFFSET	0
@@ -255,6 +256,8 @@ static struct fg_sram_param pmi8998_v2_sram_params[] = {
 		fg_decode_cc_soc),
 	PARAM(ACT_BATT_CAP, ACT_BATT_CAP_BKUP_WORD, ACT_BATT_CAP_BKUP_OFFSET, 2,
 		1, 1, 0, NULL, fg_decode_default),
+	PARAM(TIMEBASE, KI_COEFF_MED_DISCHG_WORD, TIMEBASE_OFFSET, 2, 1000,
+		61000, 0, fg_encode_default, NULL),
 	/* Entries below here are configurable during initialization */
 	PARAM(CUTOFF_VOLT, CUTOFF_VOLT_WORD, CUTOFF_VOLT_OFFSET, 2, 1000000,
 		244141, 0, fg_encode_voltage, NULL),
@@ -3302,6 +3305,40 @@ static int fg_memif_init(struct fg_chip *chip)
 	return fg_ima_init(chip);
 }
 
+static int fg_adjust_timebase(struct fg_chip *chip)
+{
+	int rc = 0, die_temp;
+	s32 time_base = 0;
+	u8 buf[2] = {0};
+
+	if ((chip->wa_flags & PM660_TSMC_OSC_WA) && chip->die_temp_chan) {
+		rc = iio_read_channel_processed(chip->die_temp_chan, &die_temp);
+		if (rc < 0) {
+			pr_err("Error in reading die_temp, rc:%d\n", rc);
+			return rc;
+		}
+
+		rc = fg_lerp(fg_tsmc_osc_table, ARRAY_SIZE(fg_tsmc_osc_table),
+					die_temp / 1000, &time_base);
+		if (rc < 0) {
+			pr_err("Error to lookup fg_tsmc_osc_table rc=%d\n", rc);
+			return rc;
+		}
+
+		fg_encode(chip->sp, FG_SRAM_TIMEBASE, time_base, buf);
+		rc = fg_sram_write(chip,
+			chip->sp[FG_SRAM_TIMEBASE].addr_word,
+			chip->sp[FG_SRAM_TIMEBASE].addr_byte, buf,
+			chip->sp[FG_SRAM_TIMEBASE].len, FG_IMA_DEFAULT);
+		if (rc < 0) {
+			pr_err("Error in writing timebase, rc=%d\n", rc);
+			return rc;
+		}
+	}
+
+	return 0;
+}
+
 /* INTERRUPT HANDLERS STAY HERE */
 
 static irqreturn_t fg_mem_xcp_irq_handler(int irq, void *data)
@@ -3419,6 +3456,10 @@ static irqreturn_t fg_delta_batt_temp_irq_handler(int irq, void *data)
 	chip->health = prop.intval;
 
 	if (chip->last_batt_temp != batt_temp) {
+		rc = fg_adjust_timebase(chip);
+		if (rc < 0)
+			pr_err("Error in adjusting timebase, rc=%d\n", rc);
+
 		chip->last_batt_temp = batt_temp;
 		power_supply_changed(chip->batt_psy);
 	}
@@ -3488,6 +3529,10 @@ static irqreturn_t fg_delta_msoc_irq_handler(int irq, void *data)
 	if (rc < 0)
 		pr_err("Error in validating ESR, rc=%d\n", rc);
 
+	rc = fg_adjust_timebase(chip);
+	if (rc < 0)
+		pr_err("Error in adjusting timebase, rc=%d\n", rc);
+
 	if (batt_psy_initialized(chip))
 		power_supply_changed(chip->batt_psy);
 
@@ -3829,6 +3874,8 @@ static int fg_parse_dt(struct fg_chip *chip)
 		chip->sp = pmi8998_v2_sram_params;
 		chip->alg_flags = pmi8998_v2_alg_flags;
 		chip->use_ima_single_mode = true;
+		if (chip->pmic_rev_id->fab_id == PM660_FAB_ID_TSMC)
+			chip->wa_flags |= PM660_TSMC_OSC_WA;
 		break;
 	default:
 		return -EINVAL;
@@ -4163,6 +4210,21 @@ static int fg_gen3_probe(struct platform_device *pdev)
 		return rc;
 	}
 
+	rc = of_property_match_string(chip->dev->of_node,
+				"io-channel-names", "rradc_die_temp");
+	if (rc >= 0) {
+		chip->die_temp_chan = iio_channel_get(chip->dev,
+						"rradc_die_temp");
+		if (IS_ERR(chip->die_temp_chan)) {
+			if (PTR_ERR(chip->die_temp_chan) != -EPROBE_DEFER)
+				pr_err("rradc_die_temp unavailable %ld\n",
+					PTR_ERR(chip->die_temp_chan));
+			rc = PTR_ERR(chip->die_temp_chan);
+			chip->die_temp_chan = NULL;
+			return rc;
+		}
+	}
+
 	chip->awake_votable = create_votable("FG_WS", VOTE_SET_ANY, fg_awake_cb,
 					chip);
 	if (IS_ERR(chip->awake_votable)) {