linux-kernel - [PATCH] mfd: tps65219: Add support for soft shutdown via sys-off API

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Message-Id: <20230203140150.13071-1-jneanne@baylibre.com>
Date:   Fri,  3 Feb 2023 15:01:50 +0100
From:   Jerome Neanne <jneanne@...libre.com>
To:     tony@...mide.com, lee@...nel.org
Cc:     linux-omap@...r.kernel.org, linux-kernel@...r.kernel.org,
        khilman@...libre.com, nm@...com, afd@...com, msp@...libre.com,
        Jerome Neanne <jneanne@...libre.com>
Subject: [PATCH] mfd: tps65219: Add support for soft shutdown via sys-off API

Use new API for power-off mode support:
Link: https://lwn.net/Articles/894511/
Link: https://lore.kernel.org/all/7hfseqa7l0.fsf@baylibre.com/

sys-off API allows support of shutdown handler and restart handler.

Shutdown was not supported before that enhancement.
This is required for platform that are not using PSCI.

Test:
- restart:
  # reboot
  Default is cold reset:
  # cat /sys/kernel/reboot/mode
  Switch boot mode to warm reset:
  # echo warm > /sys/kernel/reboot/mode
- power-off:
  # halt

Tested on AM62-SP-SK board.

Signed-off-by: Jerome Neanne <jneanne@...libre.com>
Suggested-by: Andrew Davis <afd@...com>
---
 drivers/mfd/tps65219.c | 45 +++++++++++++++++++++++++++++++-----------
 1 file changed, 34 insertions(+), 11 deletions(-)

diff --git a/drivers/mfd/tps65219.c b/drivers/mfd/tps65219.c
index 0e402fda206b..c134f3f6e202 100644
--- a/drivers/mfd/tps65219.c
+++ b/drivers/mfd/tps65219.c
@@ -25,25 +25,34 @@ static int tps65219_cold_reset(struct tps65219 *tps)
 				  TPS65219_MFP_COLD_RESET_I2C_CTRL_MASK);
 }
 
-static int tps65219_restart(struct notifier_block *this,
-			    unsigned long reboot_mode, void *cmd)
+static int tps65219_soft_shutdown(struct tps65219 *tps)
 {
-	struct tps65219 *tps;
+	return regmap_update_bits(tps->regmap, TPS65219_REG_MFP_CTRL,
+				  TPS65219_MFP_I2C_OFF_REQ_MASK,
+				  TPS65219_MFP_I2C_OFF_REQ_MASK);
+}
 
-	tps = container_of(this, struct tps65219, nb);
+static int tps65219_power_off_handler(struct sys_off_data *data)
+{
+	tps65219_soft_shutdown(data->cb_data);
+	return NOTIFY_DONE;
+}
 
+static int tps65219_restart(struct tps65219 *tps,
+			    unsigned long reboot_mode)
+{
 	if (reboot_mode == REBOOT_WARM)
 		tps65219_warm_reset(tps);
 	else
 		tps65219_cold_reset(tps);
-
 	return NOTIFY_DONE;
 }
 
-static struct notifier_block pmic_rst_restart_nb = {
-	.notifier_call = tps65219_restart,
-	.priority = 200,
-};
+static int tps65219_restart_handler(struct sys_off_data *data)
+{
+	tps65219_restart(data->cb_data, data->mode);
+	return NOTIFY_DONE;
+}
 
 static const struct resource tps65219_pwrbutton_resources[] = {
 	DEFINE_RES_IRQ_NAMED(TPS65219_INT_PB_FALLING_EDGE_DETECT, "falling"),
@@ -269,13 +278,27 @@ static int tps65219_probe(struct i2c_client *client)
 		}
 	}
 
-	tps->nb = pmic_rst_restart_nb;
-	ret = register_restart_handler(&tps->nb);
+	ret = devm_register_sys_off_handler(tps->dev,
+					    SYS_OFF_MODE_RESTART,
+					    SYS_OFF_PRIO_HIGH,
+					    tps65219_restart_handler,
+					    tps);
+
 	if (ret) {
 		dev_err(tps->dev, "cannot register restart handler, %d\n", ret);
 		return ret;
 	}
 
+	ret = devm_register_sys_off_handler(tps->dev,
+					    SYS_OFF_MODE_POWER_OFF,
+					    SYS_OFF_PRIO_DEFAULT,
+					    tps65219_power_off_handler,
+					    tps);
+	if (ret) {
+		dev_err(tps->dev, "failed to register sys-off handler: %d\n",
+			ret);
+		return ret;
+	}
 	return 0;
 }
 
-- 
2.34.1