[PATCH 2/4] power: reset: add Odroid Go Ultra poweroff driver

[Neil Armstrong <neil.armstrong@linaro.org>]

The Hardkernel Odroid Go Ultra poweroff scheme requires requesting a poweroff
to its two PMICs in order, this represents the poweroff scheme needed to complete
a clean poweroff of the system.

This implement this scheme, and overrides the PSCI pm_power_off.

Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
---
 drivers/power/reset/Kconfig                    |   7 ++
 drivers/power/reset/Makefile                   |   1 +
 drivers/power/reset/odroid-go-ultra-poweroff.c | 122 +++++++++++++++++++++++++
 3 files changed, 130 insertions(+)

diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index a8c46ba5878f..26860c2e05a9 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -141,6 +141,13 @@ config POWER_RESET_OCELOT_RESET
 	help
 	  This driver supports restart for Microsemi Ocelot SoC and similar.
 
+config POWER_RESET_ODROID_GO_ULTRA_POWEROFF
+	bool "Odroid Go Ultra power-off driver"
+	depends on ARCH_MESON || COMPILE_TEST
+	depends on MFD_RK808
+	help
+	  This driver supports Power off for Odroid Go Ultra device.
+
 config POWER_RESET_OXNAS
 	bool "OXNAS SoC restart driver"
 	depends on ARCH_OXNAS
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index 0a39424fc558..d763e6735ee3 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_POWER_RESET_MT6323) += mt6323-poweroff.o
 obj-$(CONFIG_POWER_RESET_OXNAS) += oxnas-restart.o
 obj-$(CONFIG_POWER_RESET_QCOM_PON) += qcom-pon.o
 obj-$(CONFIG_POWER_RESET_OCELOT_RESET) += ocelot-reset.o
+obj-$(CONFIG_POWER_RESET_ODROID_GO_ULTRA_POWEROFF) += odroid-go-ultra-poweroff.o
 obj-$(CONFIG_POWER_RESET_PIIX4_POWEROFF) += piix4-poweroff.o
 obj-$(CONFIG_POWER_RESET_LTC2952) += ltc2952-poweroff.o
 obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
diff --git a/drivers/power/reset/odroid-go-ultra-poweroff.c b/drivers/power/reset/odroid-go-ultra-poweroff.c
new file mode 100644
index 000000000000..89ae21790f65
--- /dev/null
+++ b/drivers/power/reset/odroid-go-ultra-poweroff.c
@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2022 Neil Armstrong <neil.armstrong@linaro.org>
+ */
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+#include <linux/mfd/rk808.h>
+#include <linux/regmap.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+
+static struct rk808 *rk817;
+static struct rk808 *rk818;
+
+static void odroid_go_ultra_do_poweroff(void)
+{
+	int ret;
+
+	BUG_ON(!rk817);
+	BUG_ON(!rk818);
+
+	/* RK817 */
+	ret = regmap_update_bits(rk817->regmap, RK817_SYS_CFG(3), DEV_OFF, DEV_OFF);
+	if (ret)
+		pr_err("%s: failed to poweroff rk817\n", __func__);
+
+	/* RK818 */
+	ret = regmap_update_bits(rk818->regmap, RK818_DEVCTRL_REG, DEV_OFF, DEV_OFF);
+	if (ret)
+		pr_err("%s: failed to poweroff rk817\n", __func__);
+
+	WARN_ON(1);
+}
+
+static int odroid_go_ultra_poweroff_get_pmic_drvdata(struct platform_device *pdev,
+						     const char *property,
+						     struct rk808 **pmic)
+{
+	struct device_node *pmic_node;
+	struct i2c_client *pmic_client;
+
+	pmic_node = of_parse_phandle(pdev->dev.of_node, property, 0);
+	if (!pmic_node)
+		return -ENODEV;
+
+	pmic_client = of_find_i2c_device_by_node(pmic_node);
+	of_node_put(pmic_node);
+	if (!pmic_client)
+		return -EPROBE_DEFER;
+
+	*pmic = i2c_get_clientdata(pmic_client);
+
+	put_device(&pmic_client->dev);
+
+	if (!*pmic)
+		return -EPROBE_DEFER;
+
+	return 0;
+}
+
+static int odroid_go_ultra_poweroff_probe(struct platform_device *pdev)
+{
+	int ret;
+
+	/* RK818 */
+	ret = odroid_go_ultra_poweroff_get_pmic_drvdata(pdev, "hardkernel,rk818-pmic", &rk818);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to get rk818 mfd data (%d)\n", ret);
+		return ret;
+	}
+
+	/* RK817 */
+	ret = odroid_go_ultra_poweroff_get_pmic_drvdata(pdev, "hardkernel,rk817-pmic", &rk817);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to get rk817 mfd data (%d)\n", ret);
+		return ret;
+	}
+
+	/* If a pm_power_off function has already been added, warn we're overriding */
+	if (pm_power_off != NULL)
+		dev_warn(&pdev->dev,
+			"%s: pm_power_off function already registered, overriding\n",
+		       __func__);
+
+	pm_power_off = odroid_go_ultra_do_poweroff;
+
+	return 0;
+}
+
+static int odroid_go_ultra_poweroff_remove(struct platform_device *pdev)
+{
+	if (pm_power_off == &odroid_go_ultra_do_poweroff)
+		pm_power_off = NULL;
+
+	rk817 = NULL;
+	rk818 = NULL;
+
+	return 0;
+}
+
+static const struct of_device_id of_odroid_go_ultra_poweroff_match[] = {
+	{ .compatible = "hardkernel,odroid-go-ultra-poweroff", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, of_odroid_go_ultra_poweroff_match);
+
+static struct platform_driver odroid_go_ultra_poweroff_driver = {
+	.probe = odroid_go_ultra_poweroff_probe,
+	.remove = odroid_go_ultra_poweroff_remove,
+	.driver = {
+		.name = "odroid-go-ultra-poweroff",
+		.of_match_table = of_odroid_go_ultra_poweroff_match,
+	},
+};
+
+module_platform_driver(odroid_go_ultra_poweroff_driver);
+
+MODULE_AUTHOR("Neil Armstrong <neil.armstrong@linaro.org>");
+MODULE_DESCRIPTION("Odroid Go Ultra poweroff driver");
+MODULE_LICENSE("GPL");

-- 
b4 0.10.1