From 510f276df2b91efd73f6c53be62b7e692ff533c1 Mon Sep 17 00:00:00 2001 From: Benjamin Bara Date: Sat, 15 Jul 2023 09:53:27 +0200 Subject: [PATCH] mfd: tps6586x: Register restart handler There are a couple of boards which use a tps6586x as "ti,system-power-controller", e.g. the tegra20-tamonten.dtsi. For these, the only registered restart handler is the warm reboot via tegra's PMC. As the bootloader of the tegra20 requires the VDE, it must be ensured that VDE is enabled (which is the case after a cold reboot). For the "normal reboot", this is basically the case since 8f0c714ad9be. However, this workaround is not executed in case of an emergency restart. In case of an emergency restart, the system now simply hangs in the bootloader, as VDE is not enabled (because it is not used). The TPS658629-Q1 provides a SOFT RST bit in the SUPPLYENE reg to request a (cold) reboot, which takes at least 20ms (as the data sheet states). This avoids the hang-up. Tested on a TPS658640. Reviewed-by: Dmitry Osipenko Signed-off-by: Benjamin Bara Link: https://lore.kernel.org/r/20230327-tegra-pmic-reboot-v7-5-18699d5dcd76@skidata.com Signed-off-by: Lee Jones --- drivers/mfd/tps6586x.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/drivers/mfd/tps6586x.c b/drivers/mfd/tps6586x.c index 965065562de6..7e8160b94784 100644 --- a/drivers/mfd/tps6586x.c +++ b/drivers/mfd/tps6586x.c @@ -30,6 +30,7 @@ #include #define TPS6586X_SUPPLYENE 0x14 +#define SOFT_RST_BIT BIT(0) #define EXITSLREQ_BIT BIT(1) #define SLEEP_MODE_BIT BIT(3) @@ -475,6 +476,19 @@ static int tps6586x_power_off_handler(struct sys_off_data *data) return notifier_from_errno(-ETIME); } +static int tps6586x_restart_handler(struct sys_off_data *data) +{ + int ret; + + /* Put the PMIC into hard reboot state. This takes at least 20ms. */ + ret = tps6586x_set_bits(data->dev, TPS6586X_SUPPLYENE, SOFT_RST_BIT); + if (ret) + return notifier_from_errno(ret); + + mdelay(50); + return notifier_from_errno(-ETIME); +} + static void tps6586x_print_version(struct i2c_client *client, int version) { const char *name; @@ -575,6 +589,13 @@ 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, + NULL); + if (ret) { + dev_err(&client->dev, "register restart handler failed: %d\n", ret); + goto err_add_devs; + } } return 0;