Re: [2/2] mfd: max77620: Add low battery monitor support

[Billy Laws]

>This patch adds PMIC configurations for low-battery
>monitoring by handling max77620 register CNFGGLBL1.
>
It might be an idea to add lbhyst configuration here and support using
custom lbdac values to specify a different cutoff point.

See: https://datasheetspdf.com/pdf-file/924230/Maxim/MAX8698C/1Â; pg 46
>Signed-off-by: Laxman Dewangan <ldewangan@xxxxxxxxxx>
>Signed-off-by: Venkat Reddy Talla <vreddytalla@xxxxxxxxxx>
>Signed-off-by: Mark Zhang <markz@xxxxxxxxxx>
>---
> drivers/mfd/max77620.c | 57 +++++++++++++++++++++++++++++++++++++++++-
> 1 file changed, 56 insertions(+), 1 deletion(-)
>
>diff --git a/drivers/mfd/max77620.c b/drivers/mfd/max77620.c
>index f58143103185..9e50d145afd8 100644
>--- a/drivers/mfd/max77620.c
>+++ b/drivers/mfd/max77620.c
>@@ -474,6 +474,57 @@ static int 
max77620_init_backup_battery_charging(struct max77620_chip *chip)
>Â return ret;
> }
>
>+static int max77620_init_low_battery_monitor(struct max77620_chip *chip)
>+{
>+ struct device *dev = chip->dev;
>+ struct device_node *np;
>+ bool pval;
>+ u8 mask = 0;
>+ u8 val = 0;
>+ int ret;
>+
>+ np = of_get_child_by_name(dev->of_node, "low-battery-monitor");
>+ if (!np) {
>+ dev_info(dev, "Low battery monitoring support disabled\n");
>+ return 0;
>+ }
>+
>+ pval = of_property_read_bool(np, "maxim,low-battery-dac-enable");
>+ if (pval) {
>+ mask |= MAX77620_CNFGGLBL1_LBDAC_EN;
>+ val |= MAX77620_CNFGGLBL1_LBDAC_EN;
>+ }
>+
>+ pval = of_property_read_bool(np, "maxim,low-battery-dac-disable");
>+ if (pval)
>+ mask |= MAX77620_CNFGGLBL1_LBDAC_EN;
>+
>+ pval = of_property_read_bool(np, "maxim,low-battery-shutdown-enable");
>+ if (pval) {
>+ mask |= MAX77620_CNFGGLBL1_MPPLD;
>+ val |= MAX77620_CNFGGLBL1_MPPLD;
>+ }
>+
>+ pval = of_property_read_bool(np, "maxim,low-battery-shutdown-disable");
>+ if (pval)
>+ mask |= MAX77620_CNFGGLBL1_MPPLD;
>+
>+ pval = of_property_read_bool(np, "maxim,low-battery-reset-enable");
>+ if (pval) {
>+ mask |= MAX77620_CNFGGLBL1_LBRSTEN;
>+ val |= MAX77620_CNFGGLBL1_LBRSTEN;
>+ }
>+
>+ pval = of_property_read_bool(np, "maxim,low-battery-reset-disable");
>+ if (pval)
>+ mask |= MAX77620_CNFGGLBL1_LBRSTEN;
>+
>+ ret = regmap_update_bits(chip->rmap, MAX77620_REG_CNFGGLBL1, mask, val);
>+ if (ret < 0)
>+ dev_err(dev, "Reg CNFGGLBL1 update failed: %d\n", ret);
>+ return ret;
>+}
>+
> static int max77620_read_es_version(struct max77620_chip *chip)
> {
>Â unsigned int val;
>@@ -563,7 +614,11 @@ static int max77620_probe(struct i2c_client *client,
>Â if (ret < 0)
>Â return ret;
>
>- ret =Â devm_mfd_add_devices(chip->dev, PLATFORM_DEVID_NONE,
>+ ret = max77620_init_low_battery_monitor(chip);
>+ if (ret < 0)
>+ return ret;
>+
>+ ret = devm_mfd_add_devices(chip->dev, PLATFORM_DEVID_NONE,
>ÂÂÂÂÂ mfd_cells, n_mfd_cells, NULL, 0,
>ÂÂÂÂÂ regmap_irq_get_domain(chip->top_irq_data));
>Â if (ret < 0) {