mfd: tps6594: Add board power-off support

Add a system level power-off handler if the "system-power-controller"
flag is set for this device in the device tree.

A power-off request is triggered by writing the TRIGGER_I2C_0 bit (which
is actually just a convention and really depends on the freely
programmable FSM).

Co-developed-by: Job Sava <jsava@criticallink.com>
Signed-off-by: Job Sava <jsava@criticallink.com>
Signed-off-by: Michael Walle <mwalle@kernel.org>
Link: https://lore.kernel.org/r/20250826134631.1499936-4-mwalle@kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>

diff --git a/drivers/mfd/tps6594-core.c b/drivers/mfd/tps6594-core.c
index 9195c90594898f3605831bf85fbac6a7204a4d0a..7127af7142f54b1ecfc2c74110e7f5fedb37d56b 100644 (file)
--- a/drivers/mfd/tps6594-core.c
+++ b/drivers/mfd/tps6594-core.c
@@ -15,6 +15,7 @@
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/of.h>
+#include <linux/reboot.h>
 
 #include <linux/mfd/core.h>
 #include <linux/mfd/tps6594.h>
@@ -688,6 +689,19 @@ static int tps6594_enable_crc(struct tps6594 *tps)
        return ret;
 }
 
+static int tps6594_power_off_handler(struct sys_off_data *data)
+{
+       struct tps6594 *tps = data->cb_data;
+       int ret;
+
+       ret = regmap_update_bits(tps->regmap, TPS6594_REG_FSM_I2C_TRIGGERS,
+                                TPS6594_BIT_TRIGGER_I2C(0), TPS6594_BIT_TRIGGER_I2C(0));
+       if (ret)
+               return notifier_from_errno(ret);
+
+       return NOTIFY_DONE;
+}
+
 int tps6594_device_init(struct tps6594 *tps, bool enable_crc)
 {
        struct device *dev = tps->dev;
@@ -770,6 +784,12 @@ int tps6594_device_init(struct tps6594 *tps, bool enable_crc)
                        return dev_err_probe(dev, ret, "Failed to add RTC child device\n");
        }
 
+       if (of_device_is_system_power_controller(dev->of_node)) {
+               ret = devm_register_power_off_handler(tps->dev, tps6594_power_off_handler, tps);
+               if (ret)
+                       return dev_err_probe(dev, ret, "Failed to register power-off handler\n");
+       }
+
        return 0;
 }
 EXPORT_SYMBOL_GPL(tps6594_device_init);