[PATCH v3 14/15] charger: max14577: Configure battery-dependent settings from DTS

On Thu, 2014-02-20 at 12:00 +0530, Jenny Tc wrote:

On Mon, Feb 17, 2014 at 10:05:49AM +0100, Krzysztof Kozlowski wrote:

quoted

+static inline int max14577_init_eoc(struct max14577_charger *chg,
+		unsigned int uamp)
+{
+	unsigned int current_bits = 0xf;
+	u8 reg_data;
+
+	switch (chg->maxim_core->dev_type) {
+	case MAXIM_DEVICE_TYPE_MAX77836:
+		if (uamp < 5000)
+			return -EINVAL; /* Requested current is too low */
+
+		if (uamp == 7500)
+			current_bits = 0x0;

if (uamp <= 7500) ?

(uamp < 7500) will be mapped to 5000 uA (0x1) so it will be OK. It is
safer to use lower current. The register description looks like:
0000 - 7.5 mA
0001 -  5 mA
0010 - 10 mA
0011 - 15 mA
...
1010 - 50 mA
1011 - 60 mA
1111 - 100 mA

However for value between <7501, 9999> this function will return 0x1
(5000 uA) which is not perfect. Better is to return 0x0 (7500 uA).
I'll fix this in next version of patch.

quoted

+	/* Initialize Overvoltage-Protection Threshold */
+	switch (chg->pdata->ovp_uvolt) {
+	case 7500000:
+		reg_data = 0x0;
+		break;
+	case 6000000:
+	case 6500000:
+	case 7000000:
+		reg_data = 0x1 + (chg->pdata->ovp_uvolt - 6000000) / 500000;
+		break;

Is it battery OVP or charger source OVP? If it's battery OVP, then  minimum
level as 6V seems to be unsafe even for 4.4V batteries.

It is on charger (input). Anyway only these 4 values are supported (6.0,
6.5, 7.0, 7.5 volts).


Best regards,
Krzysztof