Messages in this thread | | | Date | Sun, 19 Mar 2023 21:10:38 +0800 | Subject | Re: [PATCH 13/15] reset: Add Nuvoton ma35d1 reset driver support | From | Jacky Huang <> |
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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@nuvoton.com> >> >> 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@nuvoton.com> >> --- >> 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@nuvoton.com> >> + */ >> + >> +#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
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