Dear Ilpo,
On 2023/3/16 下午 11:05, Ilpo Järvinen wrote:
On Wed, 15 Mar 2023, Jacky Huang wrote:
From: Jacky Huang <ychuang3@xxxxxxxxxxx>
This driver supports individual IP reset for ma35d1. The reset
control registers is a subset of system control registers.
Signed-off-by: Jacky Huang <ychuang3@xxxxxxxxxxx>
---
drivers/reset/Kconfig | 6 ++
drivers/reset/Makefile | 1 +
drivers/reset/reset-ma35d1.c | 152 +++++++++++++++++++++++++++++++++++
3 files changed, 159 insertions(+)
create mode 100644 drivers/reset/reset-ma35d1.c
diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index 2a52c990d4fe..47671060d259 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -143,6 +143,12 @@ config RESET_NPCM
This enables the reset controller driver for Nuvoton NPCM
BMC SoCs.
+config RESET_NUVOTON_MA35D1
+ bool "Nuvton MA35D1 Reset Driver"
+ default ARCH_NUVOTON
+ help
+ This enables the reset controller driver for Nuvoton MA35D1 SoC.
+
config RESET_OXNAS
bool
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index 3e7e5fd633a8..fd52dcf66a99 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_RESET_MCHP_SPARX5) += reset-microchip-sparx5.o
obj-$(CONFIG_RESET_MESON) += reset-meson.o
obj-$(CONFIG_RESET_MESON_AUDIO_ARB) += reset-meson-audio-arb.o
obj-$(CONFIG_RESET_NPCM) += reset-npcm.o
+obj-$(CONFIG_RESET_NUVOTON_MA35D1) += reset-ma35d1.o
obj-$(CONFIG_RESET_OXNAS) += reset-oxnas.o
obj-$(CONFIG_RESET_PISTACHIO) += reset-pistachio.o
obj-$(CONFIG_RESET_POLARFIRE_SOC) += reset-mpfs.o
diff --git a/drivers/reset/reset-ma35d1.c b/drivers/reset/reset-ma35d1.c
new file mode 100644
index 000000000000..bdd39483ca4e
--- /dev/null
+++ b/drivers/reset/reset-ma35d1.c
@@ -0,0 +1,152 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 Nuvoton Technology Corp.
+ * Author: Chi-Fang Li <cfli0@xxxxxxxxxxx>
+ */
+
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/mfd/syscon.h>
+#include <linux/io.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reset-controller.h>
+#include <linux/mfd/ma35d1-sys.h>
+#include <dt-bindings/reset/nuvoton,ma35d1-reset.h>
+#include <linux/regmap.h>
+#include <linux/reboot.h>
+
+#define RST_PRE_REG 32
+
+struct ma35d1_reset_data {
+ struct reset_controller_dev rcdev;
+ struct regmap *regmap;
+};
+
+struct ma35d1_reboot_data {
+ struct notifier_block restart_handler;
+ struct regmap *regmap;
+};
+
+static int ma35d1_restart_handler(struct notifier_block *this,
+ unsigned long mode, void *cmd)
+{
+ struct ma35d1_reboot_data *data =
+ container_of(this, struct ma35d1_reboot_data,
+ restart_handler);
+ regmap_write(data->regmap, REG_SYS_IPRST0, 1 << MA35D1_RESET_CHIP);
+ return -EAGAIN;
This results -EAGAIN always???
The chip will reset immediately after the write to REG_SYS_IPRST0.
The return line should never be executed. If yes, it must be failed to
reset.
Anyway, I will modify it as
return regmap_write(data->regmap, REG_SYS_IPRST0, 1 << MA35D1_RESET_CHIP);
+}
+
+static int ma35d1_reset_update(struct reset_controller_dev *rcdev,
+ unsigned long id, bool assert)
+{
+ int reg;
+ int offset = (id / RST_PRE_REG) * 4;
+ struct ma35d1_reset_data *data =
+ container_of(rcdev, struct ma35d1_reset_data, rcdev);
+
+ regmap_read(data->regmap, REG_SYS_IPRST0 + offset, ®);
+ if (assert)
+ reg |= 1 << (id % RST_PRE_REG);
+ else
+ reg &= ~(1 << (id % RST_PRE_REG));
+
+ regmap_write(data->regmap, REG_SYS_IPRST0 + offset, reg);
+ return 0;
This returns always 0. What about regmap_read/write() errors, should the
be returned?
I will modify it as
return regmap_write(data->regmap, REG_SYS_IPRST0 + offset, reg);
And add return value check to the regmap_read().
+}
+
+static int ma35d1_reset_assert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return ma35d1_reset_update(rcdev, id, true);
+}
+
+static int ma35d1_reset_deassert(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ return ma35d1_reset_update(rcdev, id, false);
+}
+
+static int ma35d1_reset_status(struct reset_controller_dev *rcdev,
+ unsigned long id)
+{
+ int reg;
+ int offset = id / RST_PRE_REG;
+ struct ma35d1_reset_data *data =
+ container_of(rcdev, struct ma35d1_reset_data, rcdev);
+
+ regmap_read(data->regmap, REG_SYS_IPRST0 + offset, ®);
Error handling?
I will modify it as
ret = regmap_read(data->regmap, REG_SYS_IPRST0 + offset, ®);
if (ret < 0)
return ret;
+ return !!(reg & BIT(id % RST_PRE_REG));
+}
+
+static const struct reset_control_ops ma35d1_reset_ops = {
+ .assert = ma35d1_reset_assert,
+ .deassert = ma35d1_reset_deassert,
+ .status = ma35d1_reset_status,
+};
+
+static const struct of_device_id ma35d1_reset_dt_ids[] = {
+ { .compatible = "nuvoton,ma35d1-reset" },
+ { },
+};
+
+static int ma35d1_reset_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct ma35d1_reset_data *reset_data;
+ struct ma35d1_reboot_data *reboot_data;
+ int err;
+
+ if (!pdev->dev.of_node) {
+ dev_err(&pdev->dev, "Device tree node not found\n");
+ return -EINVAL;
+ }
+
+ reset_data = devm_kzalloc(dev, sizeof(*reset_data), GFP_KERNEL);
+ if (!reset_data)
+ return -ENOMEM;
+
+ reboot_data = devm_kzalloc(dev, sizeof(*reboot_data), GFP_KERNEL);
+ if (!reboot_data) {
+ devm_kfree(dev, reset_data);
Unnecessary.
OK, I will remove this devm_kfree().
+ return -ENOMEM;
+ }
+
+ reset_data->regmap = syscon_regmap_lookup_by_phandle(
+ pdev->dev.of_node, "regmap");
+ if (IS_ERR(reset_data->regmap)) {
+ dev_err(&pdev->dev, "Failed to get SYS register base\n");
+ err = PTR_ERR(reset_data->regmap);
+ goto err_out;
+ }
+ reset_data->rcdev.owner = THIS_MODULE;
+ reset_data->rcdev.nr_resets = MA35D1_RESET_COUNT;
+ reset_data->rcdev.ops = &ma35d1_reset_ops;
+ reset_data->rcdev.of_node = dev->of_node;
+
+ reboot_data->regmap = reset_data->regmap;
+ reboot_data->restart_handler.notifier_call = ma35d1_restart_handler;
+ reboot_data->restart_handler.priority = 192;
+
+ err = register_restart_handler(&reboot_data->restart_handler);
+ if (err)
+ dev_warn(&pdev->dev, "failed to register restart handler\n");
+
+ return devm_reset_controller_register(dev, &reset_data->rcdev);
+
+err_out:
+ devm_kfree(dev, reset_data);
+ devm_kfree(dev, reboot_data);
These are unnecessary since the probe is failing.
OK, I will make it just return err.
+ return err;
+}
+
+static struct platform_driver ma35d1_reset_driver = {
+ .probe = ma35d1_reset_probe,
+ .driver = {
+ .name = "ma35d1-reset",
+ .of_match_table = ma35d1_reset_dt_ids,
+ },
+};
+
+builtin_platform_driver(ma35d1_reset_driver);
Best regards,
Jacky Huang
