regulator: fixed: add off-on-delay

Depends on board design, the gpio controlling regulator may
connects with a big capacitance. When need off, it takes some time
to let the regulator to be truly off. If not add enough delay, the
regulator might have always been on, so introduce off-on-delay to
handle such case.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/1572311875-22880-3-git-send-email-peng.fan@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/drivers/regulator/fixed.c b/drivers/regulator/fixed.c
index f815330..bc0bbd9 100644
--- a/drivers/regulator/fixed.c
+++ b/drivers/regulator/fixed.c
@@ -123,6 +123,7 @@
 		config->enabled_at_boot = true;
 
 	of_property_read_u32(np, "startup-delay-us", &config->startup_delay);
+	of_property_read_u32(np, "off-on-delay-us", &config->off_on_delay);
 
 	if (of_find_property(np, "vin-supply", NULL))
 		config->input_supply = "vin";
@@ -189,6 +190,7 @@
 	}
 
 	drvdata->desc.enable_time = config->startup_delay;
+	drvdata->desc.off_on_delay = config->off_on_delay;
 
 	if (config->input_supply) {
 		drvdata->desc.supply_name = devm_kstrdup(&pdev->dev,
diff --git a/include/linux/regulator/fixed.h b/include/linux/regulator/fixed.h
index d44ce5f..5531994 100644
--- a/include/linux/regulator/fixed.h
+++ b/include/linux/regulator/fixed.h
@@ -36,6 +36,7 @@
 	const char *input_supply;
 	int microvolts;
 	unsigned startup_delay;
+	unsigned int off_on_delay;
 	unsigned enabled_at_boot:1;
 	struct regulator_init_data *init_data;
 };