From: Freddy Hsin <freddy.hsin@xxxxxxxxxxxx>
This driver parses the reboot commands like "reboot bootloader"
and "reboot recovery" to get a boot mode described in the
device tree , then call the write interfae to store the boot
mode in mtk RGU (reset generation unit) non-volatile register,
which can be read by the bootloader after system reboot, then
the bootloader can take different action according to the mode
stored.
Signed-off-by: Freddy Hsin <freddy.hsin@xxxxxxxxxxxx>
---
drivers/power/reset/Kconfig | 11 ++++
drivers/power/reset/Makefile | 1 +
drivers/power/reset/mtk-reboot.c | 116 ++++++++++++++++++++++++++++++++++++++
3 files changed, 128 insertions(+)
create mode 100644 drivers/power/reset/mtk-reboot.c
diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
index a564237..31fedb8 100644
--- a/drivers/power/reset/Kconfig
+++ b/drivers/power/reset/Kconfig
@@ -256,5 +256,16 @@ config NVMEM_REBOOT_MODE
then the bootloader can read it and take different
action according to the mode.
+config MTK_REBOOT_MODE
+ tristate "Mediatek SoCs reset driver"
+ depends on OF
+ depends on REGMAP
+ select REBOOT_MODE
+ help
+ Say y here will enable reboot mode driver. This will
+ get reboot mode arguments and store it in RGU mapped
+ register, then the bootloader can read it to take different
+ action according to the mode.
+
endif
diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
index 85da3198..2c64104 100644
--- a/drivers/power/reset/Makefile
+++ b/drivers/power/reset/Makefile
@@ -30,3 +30,4 @@ obj-$(CONFIG_REBOOT_MODE) += reboot-mode.o
obj-$(CONFIG_SYSCON_REBOOT_MODE) += syscon-reboot-mode.o
obj-$(CONFIG_POWER_RESET_SC27XX) += sc27xx-poweroff.o
obj-$(CONFIG_NVMEM_REBOOT_MODE) += nvmem-reboot-mode.o
+obj-$(CONFIG_MTK_REBOOT_MODE) += mtk-reboot.o
diff --git a/drivers/power/reset/mtk-reboot.c b/drivers/power/reset/mtk-reboot.c
new file mode 100644
index 0000000..545c427
--- /dev/null
+++ b/drivers/power/reset/mtk-reboot.c
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 MediaTek Inc.
+ * Author Freddy Hsin <freddy.hsin@xxxxxxxxxxxx>
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+#include <linux/of_address.h>
+#include <linux/reboot-mode.h>
+
+static const struct regmap_config mtk_regmap_config = {
+ .reg_bits = 32,
+ .val_bits = 32,
+ .reg_stride = 4,
+};
+
+struct mtk_reboot_mode {
+ struct regmap *map;
+ struct reboot_mode_driver reboot;
+ u32 offset;
+ u32 mask;
+};
+
+static int mtk_reboot_mode_write(struct reboot_mode_driver *reboot,
+ unsigned int magic)
+{
+ struct mtk_reboot_mode *mtk_rbm;
+ int ret;
+
+ mtk_rbm = container_of(reboot, struct mtk_reboot_mode, reboot);
+
+ ret = regmap_update_bits(mtk_rbm->map, mtk_rbm->offset,
+ mtk_rbm->mask, magic);
+ if (ret < 0)
+ dev_info(reboot->dev, "update reboot mode bits failed\n");
+
+ return ret;
+}
+
+static int mtk_regmap_lookup_by_phandle(struct device *dev,
+ struct mtk_reboot_mode *mtk_rbm)
+{
+ struct device_node *toprgu_np;
+ struct device_node *np = dev->of_node;
+ void __iomem *base;
+
+ toprgu_np = of_parse_phandle(np, "regmap", 0);
+
+ if (!of_device_is_compatible(toprgu_np, "mediatek,toprgu"))
+ return -EINVAL;
+
+ base = of_iomap(toprgu_np, 0);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ mtk_rbm->map = devm_regmap_init_mmio(dev, base,
+ &mtk_regmap_config);
+ return PTR_ERR_OR_ZERO(mtk_rbm->map);
+}
+
+static int mtk_reboot_mode_probe(struct platform_device *pdev)
+{
+ int ret;
+ struct mtk_reboot_mode *mtk_rbm;
+
+ mtk_rbm = devm_kzalloc(&pdev->dev, sizeof(*mtk_rbm), GFP_KERNEL);
+ if (!mtk_rbm)
+ return -ENOMEM;
+
+ mtk_rbm->reboot.dev = &pdev->dev;
+ mtk_rbm->reboot.write = mtk_reboot_mode_write;
+ mtk_rbm->mask = 0xf;
+
+ ret = mtk_regmap_lookup_by_phandle(&pdev->dev, mtk_rbm);
+ if (ret) {
+ dev_info(&pdev->dev, "Couldn't create the toprgu regmap\n");
+ return -EINVAL;
+ }
+
+ if (of_property_read_u32(pdev->dev.of_node, "offset",
+ &mtk_rbm->offset))
+ return -EINVAL;
+
+ of_property_read_u32(pdev->dev.of_node, "mask", &mtk_rbm->mask);
+
+ ret = devm_reboot_mode_register(&pdev->dev, &mtk_rbm->reboot);
+ if (ret)
+ dev_info(&pdev->dev, "can't register reboot mode\n");
+
+ return ret;
+}
+
+static const struct of_device_id mtk_reboot_mode_of_match[] = {
+ { .compatible = "toprgu-reboot-mode" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, mtk_reboot_mode_of_match);
+
+static struct platform_driver mtk_reboot_mode_driver = {
+ .probe = mtk_reboot_mode_probe,
+ .driver = {
+ .name = "toprgu-reboot-mode",
+ .of_match_table = mtk_reboot_mode_of_match,
+ },
+};
+module_platform_driver(mtk_reboot_mode_driver);
+
+MODULE_AUTHOR("Freddy Hsin <freddy.hsin@xxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Mediatek reboot mode driver");
+MODULE_LICENSE("GPL v2");
--
1.7.9.5
