Re: [PATCH 1/2] power: reset: add driver for Hardkernel's Odroid boards

[Joonyoung Shim <jy0922.shim@samsung.com>]

Hi,

On 01/22/2015 10:06 AM, Sebastian Reichel wrote:
> Hi,
> 
> On Wed, Oct 29, 2014 at 02:13:28PM +0100, Marek Szyprowski wrote:
>> This patch adds a driver implementing correct reboot and poweroff
>> procedures for Exynos4412-based Hardkernel's Odroid X/X2/U2/U3/U3+
>> boards.
> 
> Sorry it took so long. I have a couple of small requests before
> applying this (comments inline).
> 
>> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
>> ---
>>  .../bindings/power/reset/odroid-reset.txt          |  18 ++++
>>  drivers/power/reset/Kconfig                        |   6 ++
>>  drivers/power/reset/Makefile                       |   1 +
>>  drivers/power/reset/odroid-reboot.c                | 119 +++++++++++++++++++++
>>  4 files changed, 144 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/power/reset/odroid-reset.txt
>>  create mode 100644 drivers/power/reset/odroid-reboot.c
>>
>> diff --git a/Documentation/devicetree/bindings/power/reset/odroid-reset.txt b/Documentation/devicetree/bindings/power/reset/odroid-reset.txt
>> new file mode 100644
>> index 000000000000..86471a463518
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/power/reset/odroid-reset.txt
>> @@ -0,0 +1,18 @@
>> +* Device tree bindings for Hardkernel's Exynos4412 based Odroid boards
>> +
>> +This node is intended to allow proper system reboot and power off of
>> +Odroid X/X2/U2/U3/U3+ boards with eMMC storage. Without this node, board
>> +hangs during standard reset procedure.
>> +
>> +Required properties:
>> +- compatible:			hardkernel,odroid-reboot
>> +- samsung,pmureg-phandle:	phandle to Exynos PMU node
>> +- reset-gpios:			phandle and gpio-specifier to the GPIO pin
>> +				connected to the eMMC_nDET
>> +
>> +Example:
>> +odroid_reboot {
>> +	compatible = "hardkernel,odroid-reboot";
>> +	samsung,pmureg-phandle = <&pmu_system_controller>;
>> +	reset-gpio = <&gpk1 2 0>;
>> +};
>> diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
>> index f65ff49bb275..f02b13d5344f 100644
>> --- a/drivers/power/reset/Kconfig
>> +++ b/drivers/power/reset/Kconfig
>> @@ -84,6 +84,12 @@ config POWER_RESET_LTC2952
>>  	  This driver supports an external powerdown trigger and board power
>>  	  down via the LTC2952. Bindings are made in the device tree.
>>  
>> +config POWER_RESET_ODROID
>> +	bool "Hardkernel's Exynos4412 based Odroid reboot driver"
>> +	depends on POWER_RESET && ARCH_EXYNOS
> 
> once the arm specific restart handler is gone you can add ||
> COMPILE_TEST
> 
>> +	help
>> +	  Power off and restart support for Odroid boards.
>> +
>>  config POWER_RESET_QNAP
>>  	bool "QNAP power-off driver"
>>  	depends on OF_GPIO && PLAT_ORION
>> diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
>> index 76ce1c59469b..178ee86eb813 100644
>> --- a/drivers/power/reset/Makefile
>> +++ b/drivers/power/reset/Makefile
>> @@ -8,6 +8,7 @@ obj-$(CONFIG_POWER_RESET_GPIO_RESTART) += gpio-restart.o
>>  obj-$(CONFIG_POWER_RESET_HISI) += hisi-reboot.o
>>  obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o
>>  obj-$(CONFIG_POWER_RESET_LTC2952) += ltc2952-poweroff.o
>> +obj-$(CONFIG_POWER_RESET_ODROID) += odroid-reboot.o
>>  obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
>>  obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o
>>  obj-$(CONFIG_POWER_RESET_SUN6I) += sun6i-reboot.o
>> diff --git a/drivers/power/reset/odroid-reboot.c b/drivers/power/reset/odroid-reboot.c
>> new file mode 100644
>> index 000000000000..823e93539220
>> --- /dev/null
>> +++ b/drivers/power/reset/odroid-reboot.c
>> @@ -0,0 +1,119 @@
>> +/*
>> + * Copyright (c) 2014 Samsung Electronics Co., Ltd.
>> + *		http://www.samsung.com
>> + *
>> + * This program is free software; you can redistribute it and/or modify
>> + * it under the terms of the GNU General Public License as published by
>> + * the Free Software Foundation; either version 2 of the License, or
>> + * (at your option) any later version.
>> + */
>> +
>> +#include <linux/delay.h>
>> +#include <linux/gpio.h>
>> +#include <linux/io.h>
>> +#include <linux/mfd/syscon.h>
>> +#include <linux/module.h>
>> +#include <linux/of_platform.h>
>> +#include <linux/of_gpio.h>
>> +#include <linux/reboot.h>
>> +#include <linux/regmap.h>
>> +
>> +#include <asm/system_misc.h>
>> +
>> +#define PS_HOLD_CONTROL	0x330C
>> +
>> +struct odroid_reboot_data {
>> +	struct device *dev;
>> +	int power_gpio;
>> +	struct regmap *reg_pmu;
>> +	void (*reboot_func)(enum reboot_mode mode, const char *cmd);
>> +};
>> +
>> +static struct odroid_reboot_data *reboot_data;
>> +
>> +static void odroid_reboot(enum reboot_mode mode, const char *cmd)
>> +{
>> +	local_irq_disable();
>> +
>> +	gpio_set_value(reboot_data->power_gpio, 0);
>> +	mdelay(150);
>> +	gpio_set_value(reboot_data->power_gpio, 1);
>> +
>> +	reboot_data->reboot_func(mode, cmd);
>> +

It is called do_kernel_restart() if arm_pm_restart is NULL from
machine_restart of arch/arm/kernel/process.c

How about this?

if (reboot_data->reboot_func)
	reboot_data->reboot_func(mode, cmd);
else
	do_kernel_restart(cmd);

>> +	pr_emerg("%s: waiting for reboot\n", __func__);
>> +	while (1)
>> +		;

Then this endless loop is also unnecessary.

Thanks.

>> +}
>> +
>> +static void odroid_power_off(void)
>> +{
>> +	regmap_update_bits(reboot_data->reg_pmu, PS_HOLD_CONTROL, 0xffffffff, 0x5200);
>> +	while (1) {
>> +		pr_emerg("%s: should not reach here!\n", __func__);
>> +		msleep(1000);
>> +	}
>> +}
>> +
>> +static struct odroid_reboot_data *odroid_reboot_parse_dt(struct device *dev)
>> +{
>> +	struct device_node *np = dev->of_node;
>> +	struct odroid_reboot_data *data;
>> +
>> +	data = devm_kzalloc(dev, sizeof(struct odroid_reboot_data), GFP_KERNEL);
>> +	if (!data)
>> +		return NULL;
>> +
>> +	data->power_gpio = of_get_named_gpio(np, "reset-gpios", 0);
>> +	if (!gpio_is_valid(data->power_gpio)) {
>> +		dev_err(dev, "invalid reset gpio pin\n");
>> +		return NULL;
>> +	}
>> +	devm_gpio_request(dev, data->power_gpio, "reset");
> 
> please use gpiod interface.
> 
>> +
>> +	data->reg_pmu = syscon_regmap_lookup_by_phandle(np,
>> +						"samsung,pmureg-phandle");
>> +	if (IS_ERR(data->reg_pmu)) {
>> +		dev_err(dev, "failed to map PMU registers\n");
>> +		return NULL;
>> +	}
>> +
>> +	return data;
>> +}
>> +
>> +static int odroid_reboot_probe(struct platform_device *pdev)
>> +{
>> +	struct device *dev = &pdev->dev;
>> +
>> +	if (pdev->dev.of_node)
>> +		reboot_data = odroid_reboot_parse_dt(dev);
>> +
>> +	if (!reboot_data)
>> +		return -EINVAL;
>> +
>> +	reboot_data->dev = &pdev->dev;
>> +	reboot_data->reboot_func = arm_pm_restart;
>> +
>> +	/* grab reboot arm specific hook */
>> +	arm_pm_restart = odroid_reboot;
> 
> please use register_restart_handler() and
> unregister_restart_handler() in remove function.
> 
>> +	/* register power off function */
>> +	pm_power_off = odroid_power_off;
>> +
>> +	return 0;
>> +}
>> +
>> +static struct of_device_id odroid_reboot_of_match[] = {
>> +	{ .compatible = "hardkernel,odroid-reboot", },
>> +	{ },
>> +};
>> +
>> +static struct platform_driver odroid_reboot_driver = {
>> +	.probe		= odroid_reboot_probe,
>> +	.driver		= {
>> +		.name	= "odroid-reboot",
>> +		.owner	= THIS_MODULE,
> 
> Please remove .owner line (not needed, will trigger a coccinelle
> warning).
> 
>> +		.of_match_table = of_match_ptr(odroid_reboot_of_match),
>> +	}
>> +};
>> +module_platform_driver(odroid_reboot_driver);
> 
> -- Sebastian
>