diff mbox series

[v2,2/2] mfd: tps6586x: register restart handler

Message ID 20230320220345.1463687-3-bbara93@gmail.com
State Handled Elsewhere
Headers show
Series mfd: tps6586x: register restart handler | expand

Commit Message

Benjamin Bara March 20, 2023, 10:03 p.m. UTC 
From: Benjamin Bara <benjamin.bara@skidata.com>

The TPS658629-Q1 (unfortunately the only TPS6586x with public data sheet)
provides a SOFT RST bit in the SUPPLYENE reg to request a (cold) reboot.

Use it to implement and register a restart handler.

Tested on a TPS658640.

Signed-off-by: Benjamin Bara <benjamin.bara@skidata.com>
---
 drivers/mfd/tps6586x.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

Comments

Dmitry Osipenko March 21, 2023, 2:07 a.m. UTC | #1 
On 3/21/23 01:03, Benjamin Bara wrote:
> +static int tps6586x_restart_handler(struct sys_off_data *data)
> +{
> +	unsigned long flags;
> +	struct device *tps6586x_dev = (struct device *)data->cb_data;
> +
> +	/* bring pmic into HARD REBOOT state, enforce atomic i2c xfer */
> +	local_irq_save(flags);
> +	tps6586x_set_bits(tps6586x_dev, TPS6586X_SUPPLYENE, SOFT_RST_BIT);
> +	local_irq_restore(flags);

Please change i2c_in_atomic_xfer_mode() to use preemptible() instead of
irqs_disabled() and drop the local_irq_save/restore.
Jon Hunter March 21, 2023, 7:46 a.m. UTC | #2 
On 20/03/2023 22:03, Benjamin Bara wrote:
> From: Benjamin Bara <benjamin.bara@skidata.com>
> 
> The TPS658629-Q1 (unfortunately the only TPS6586x with public data sheet)
> provides a SOFT RST bit in the SUPPLYENE reg to request a (cold) reboot.
> 
> Use it to implement and register a restart handler.


This does not explain why this is needed and/or why we are adding this.

Jon
diff mbox series

Patch

diff --git a/drivers/mfd/tps6586x.c b/drivers/mfd/tps6586x.c
index 4869155437cb..b46917231847 100644
--- a/drivers/mfd/tps6586x.c
+++ b/drivers/mfd/tps6586x.c
@@ -15,6 +15,7 @@ 
 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/irqdomain.h>
+#include <linux/irqflags.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/mutex.h>
@@ -30,6 +31,7 @@ 
 #include <linux/mfd/tps6586x.h>
 
 #define TPS6586X_SUPPLYENE	0x14
+#define SOFT_RST_BIT		BIT(0)
 #define EXITSLREQ_BIT		BIT(1)
 #define SLEEP_MODE_BIT		BIT(3)
 
@@ -470,6 +472,20 @@  static int tps6586x_power_off_handler(struct sys_off_data *data)
 	return tps6586x_set_bits(tps6586x_dev, TPS6586X_SUPPLYENE, SLEEP_MODE_BIT);
 }
 
+static int tps6586x_restart_handler(struct sys_off_data *data)
+{
+	unsigned long flags;
+	struct device *tps6586x_dev = (struct device *)data->cb_data;
+
+	/* bring pmic into HARD REBOOT state, enforce atomic i2c xfer */
+	local_irq_save(flags);
+	tps6586x_set_bits(tps6586x_dev, TPS6586X_SUPPLYENE, SOFT_RST_BIT);
+	local_irq_restore(flags);
+
+	mdelay(500);
+	return 0;
+}
+
 static void tps6586x_print_version(struct i2c_client *client, int version)
 {
 	const char *name;
@@ -570,6 +586,13 @@  static int tps6586x_i2c_probe(struct i2c_client *client)
 			dev_err(&client->dev, "register power off handler failed: %d\n", ret);
 			goto err_add_devs;
 		}
+
+		ret = devm_register_restart_handler(&client->dev, &tps6586x_restart_handler,
+						    &client->dev);
+		if (ret) {
+			dev_err(&client->dev, "register restart handler failed: %d\n", ret);
+			goto err_add_devs;
+		}
 	}
 
 	return 0;