BeagleV Starlight reset support

This converts the tps65086.txt binding description to YAML schema so dts files can be verified automatically.

Signed-off-by Emil Renner Berthing <[email protected]>

---
 .../devicetree/bindings/mfd/ti,tps65086.yaml  | 127 ++++++++++++++++++
 .../devicetree/bindings/mfd/tps65086.txt      |  54 --------
 2 files changed, 127 insertions(+), 54 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/mfd/ti,tps65086.yaml
 delete mode 100644 Documentation/devicetree/bindings/mfd/tps65086.txt

This converts the tps65086.txt binding description to YAML schema so dts files can be verified automatically.

Signed-off-by Emil Renner Berthing <[email protected]>

---
 .../devicetree/bindings/mfd/ti,tps65086.yaml  | 127 ++++++++++++++++++
 .../devicetree/bindings/mfd/tps65086.txt      |  54 --------
 2 files changed, 127 insertions(+), 54 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/mfd/ti,tps65086.yaml
 delete mode 100644 Documentation/devicetree/bindings/mfd/tps65086.txt

The BeagleV Starlight v0.9 board[1] doesn't have the IRQB line routed to the SoC, but it is still useful to be able to reach the PMIC over I2C for the other functionality it provides such as GPIOs and regulator settings.

[1] https://github.com/beagleboard/beaglev-starlight

Signed-off-by Emil Renner Berthing <[email protected]>

Acked-by Rob Herring <[email protected]>

Acked-for-MFD-by Lee Jones <[email protected]>

---
 .../devicetree/bindings/mfd/ti,tps65086.yaml  |  3 ---
 drivers/mfd/tps65086.c                        | 21 ++++++++++---------
 2 files changed, 11 insertions(+), 13 deletions(-)

The only way to reset the BeagleV Starlight v0.9 board[1] properly is to tell the PMIC to reset itself which will then assert the external reset lines of the SoC, USB hub and ethernet phy.

This adds a driver to register a reset handler to do just that.

[1] https://github.com/beagleboard/beaglev-starlight

Signed-off-by Emil Renner Berthing <[email protected]>

Acked-by Sebastian Reichel <[email protected]>

---

 drivers/power/reset/Kconfig            |  6 ++
 drivers/power/reset/Makefile           |  1 +
 drivers/power/reset/tps65086-restart.c | 98 ++++++++++++++++++++++++++
 3 files changed, 105 insertions(+)
 create mode 100644 drivers/power/reset/tps65086-restart.c

drivers/power/reset/Kconfig +6 -0

index 4d1192062508..4b563db3ab3e 100644
@@ -204,6 +204,12 @@ config POWER_RESET_ST
 	help
 	  Reset support for STMicroelectronics boards.
 
+config POWER_RESET_TPS65086
+	bool "TPS65086 restart driver"
+	depends on MFD_TPS65086
+	help
+	  This driver adds support for resetting the TPS65086 PMIC on restart.
+
 config POWER_RESET_VERSATILE
 	bool "ARM Versatile family reboot driver"
 	depends on ARM

drivers/power/reset/Makefile +1 -0

index cf3f4d02d8a5..f606a2f60539 100644
@@ -23,6 +23,7 @@ obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
 obj-$(CONFIG_POWER_RESET_REGULATOR) += regulator-poweroff.o
 obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o
 obj-$(CONFIG_POWER_RESET_ST) += st-poweroff.o
+obj-$(CONFIG_POWER_RESET_TPS65086) += tps65086-restart.o
 obj-$(CONFIG_POWER_RESET_VERSATILE) += arm-versatile-reboot.o
 obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o
 obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o

drivers/power/reset/tps65086-restart.c new file +98 -0

new file mode 100644
index 000000000000..78b89f745a3d
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2021 Emil Renner Berthing
+ */
+
+#include <linux/mfd/tps65086.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+
+struct tps65086_restart {
+	struct notifier_block handler;
+	struct device *dev;
+};
+
+static int tps65086_restart_notify(struct notifier_block *this,
+				   unsigned long mode, void *cmd)
+{
+	struct tps65086_restart *tps65086_restart =
+		container_of(this, struct tps65086_restart, handler);
+	struct tps65086 *tps65086 = dev_get_drvdata(tps65086_restart->dev->parent);
+	int ret;
+
+	ret = regmap_write(tps65086->regmap, TPS65086_FORCESHUTDN, 1);
+	if (ret) {
+		dev_err(tps65086_restart->dev, "%s: error writing to tps65086 pmic: %d\n",
+			__func__, ret);
+		return NOTIFY_DONE;
+	}
+
+	/* give it a little time */
+	mdelay(200);
+
+	WARN_ON(1);
+
+	return NOTIFY_DONE;
+}
+
+static int tps65086_restart_probe(struct platform_device *pdev)
+{
+	struct tps65086_restart *tps65086_restart;
+	int ret;
+
+	tps65086_restart = devm_kzalloc(&pdev->dev, sizeof(*tps65086_restart), GFP_KERNEL);
+	if (!tps65086_restart)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, tps65086_restart);
+
+	tps65086_restart->handler.notifier_call = tps65086_restart_notify;
+	tps65086_restart->handler.priority = 192;
+	tps65086_restart->dev = &pdev->dev;
+
+	ret = register_restart_handler(&tps65086_restart->handler);
+	if (ret) {
+		dev_err(&pdev->dev, "%s: cannot register restart handler: %d\n",
+			__func__, ret);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static int tps65086_restart_remove(struct platform_device *pdev)
+{
+	struct tps65086_restart *tps65086_restart = platform_get_drvdata(pdev);
+	int ret;
+
+	ret = unregister_restart_handler(&tps65086_restart->handler);
+	if (ret) {
+		dev_err(&pdev->dev, "%s: cannot unregister restart handler: %d\n",
+			__func__, ret);
+		return -ENODEV;
+	}
+
+	return 0;
+}
+
+static const struct platform_device_id tps65086_restart_id_table[] = {
+	{ "tps65086-reset", },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(platform, tps65086_restart_id_table);
+
+static struct platform_driver tps65086_restart_driver = {
+	.driver = {
+		.name = "tps65086-restart",
+	},
+	.probe = tps65086_restart_probe,
+	.remove = tps65086_restart_remove,
+	.id_table = tps65086_restart_id_table,
+};
+module_platform_driver(tps65086_restart_driver);
+
+MODULE_AUTHOR("Emil Renner Berthing <[email protected]>");
+MODULE_DESCRIPTION("TPS65086 restart driver");
+MODULE_LICENSE("GPL v2");

Signature · 1 line

2.32.0

The only way to reset the BeagleV Starlight v0.9 board[1] properly is to tell the PMIC to reset itself which will then assert the external reset lines of the SoC, USB hub and ethernet phy.

This adds an mfd cell entry for the reset driver doing just that.

[1] https://github.com/beagleboard/beaglev-starlight

Signed-off-by Emil Renner Berthing <[email protected]>

---
 drivers/mfd/tps65086.c | 1 +
 1 file changed, 1 insertion(+)