From 1cb82f25b5aad565487aa395448e2d208f29c067 Mon Sep 17 00:00:00 2001
From: Nathael Pajani <nathael.pajani@ed3l.fr>
Date: Sun, 30 Jan 2022 04:14:13 +0100
Subject: [PATCH] Add Cell ballancing helpers to BQ769x0 BMS support

---
 extdrv/bq769x0_bms.c         | 33 +++++++++++++++++++++++++++++++++
 include/extdrv/bq769x0_bms.h |  6 ++++++
 2 files changed, 39 insertions(+)

diff --git a/extdrv/bq769x0_bms.c b/extdrv/bq769x0_bms.c
index de04a45..76357c1 100644
--- a/extdrv/bq769x0_bms.c
+++ b/extdrv/bq769x0_bms.c
@@ -88,6 +88,10 @@ enum bq769x0_internal_reg_numbers {
 /* The documentation asks for CC_CFG to be set to 0x19 upon startup */
 #define CC_CFG_DEFAULT  0x19
 
+/* Cell balancing helpers */
+#define CELL_BALANCE(x)  (x)
+#define BCELL(x) (0x01 << ((x) - 1))
+
 
 /* Check the bms presence, return 1 if bms was found.
  * This is a basic check, it could be anything with the same address ...
@@ -378,6 +382,35 @@ int bq769x0_bms_set_ranges(struct bq769x0_bms_conf* conf,
 	return 0;
 }
 
+/* Cell balancing
+ * set corresponds to the cells set number : [1 .. 3]
+ * cell is the cell number within the set : [1 .. 5] or 0 to turn off cell balancing for this set
+ */
+int bq769x0_cell_balance(struct bq769x0_bms_conf* conf, uint8_t set, uint8_t cell)
+{
+	int ret = 0;
+	uint8_t tmp = 0;
+
+	if ((set == 0) || (set > 3)) {
+		return -1;
+	}
+	if (cell > 5) {
+		return -2;
+	}
+	/* Turn off cell balancing for this set */
+	if (cell == 0) {
+		tmp = 0;
+	} else {
+		tmp = BCELL(cell);
+	}
+	ret = bq769x0_bms_set_regs(conf, CELL_BALANCE(set), &tmp, 1);
+	if (ret != 0) {
+		conf->probe_ok = 20;
+		return ret;
+	}
+	return 0;
+}
+
 
 /* Read ADC values.
  * type is one of :
diff --git a/include/extdrv/bq769x0_bms.h b/include/extdrv/bq769x0_bms.h
index ad523cb..06a4098 100644
--- a/include/extdrv/bq769x0_bms.h
+++ b/include/extdrv/bq769x0_bms.h
@@ -123,6 +123,12 @@ int bq769x0_bms_set_ranges(struct bq769x0_bms_conf* conf,
             uint8_t uvlo, uint8_t ovp, uint8_t ocd, uint8_t scd);
 
 
+/* Cell balancing
+ * set corresponds to the cells set number : [1 .. 3]
+ * cell is the cell number within the set : [1 .. 5] or 0 to turn off cell balancing for this set
+ */
+int bq769x0_cell_balance(struct bq769x0_bms_conf* conf, uint8_t set, uint8_t cell);
+
 
 enum bq769x0_bms_adc_values {
 	ALL = 0,
-- 
2.43.0