Re: [PATCH v3 2/3] power: reset: imx-snvs-poweroff: add power off driver for i.mx6

[Mark Rutland <mark.rutland@arm.com>]

On Wed, Sep 17, 2014 at 10:57:59AM +0100, Robin Gong wrote:
> This driver register pm_power_off with snvs power off function. If
> your boards NOT use PMIC_ON_REQ to turn on/off external pmic, or use
> other pin to do, please disable the driver in dts, otherwise, your
> pm_power_off maybe overwrote by this driver.
> 
> Signed-off-by: Robin Gong <b38343@freescale.com>
> ---
>  .../bindings/power_supply/imx-snvs-poweroff.txt    |   23 +++++++
>  drivers/power/reset/Kconfig                        |    9 +++
>  drivers/power/reset/Makefile                       |    1 +
>  drivers/power/reset/imx-snvs-poweroff.c            |   66 ++++++++++++++++++++
>  4 files changed, 99 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/power_supply/imx-snvs-poweroff.txt
>  create mode 100644 drivers/power/reset/imx-snvs-poweroff.c
> 
> diff --git a/Documentation/devicetree/bindings/power_supply/imx-snvs-poweroff.txt b/Documentation/devicetree/bindings/power_supply/imx-snvs-poweroff.txt
> new file mode 100644
> index 0000000..6caf64e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/power_supply/imx-snvs-poweroff.txt
> @@ -0,0 +1,23 @@
> +i.mx6 Poweroff Driver
> +
> +SNVS_LPCR in SNVS module can power off the whole system by pull
> +PMIC_ON_REQ low if PMIC_ON_REQ is connected with external PMIC.
> +If you don't want to use PMIC_ON_REQ as power on/off control,
> +please set status='disabled' to disable this driver.
> +
> +Required Properties:
> +-compatible: "fsl,sec-v4.0-poweroff"
> +-reg: Specifies the physical address of the SNVS_LPCR register

As you describe above, this is part of the SNVS module. So why does this
need a separate node?

Surely there should just be a property on the SNVS node that desribers
whether or not this can be used?

Mark.

> +
> +Example:
> +	snvs@020cc000 {
> +		compatible = "fsl,sec-v4.0-mon", "simple-bus";
> +		#address-cells = <1>;
> +		#size-cells = <1>;
> +		ranges = <0 0x020cc000 0x4000>;
> +		.....
> +		snvs-poweroff@38 {
> +			compatible = "fsl,sec-v4.0-poweroff";
> +			reg = <0x38 0x4>;
> +		};
> +	}
> diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
> index ca41523..b26c547 100644
> --- a/drivers/power/reset/Kconfig
> +++ b/drivers/power/reset/Kconfig
> @@ -45,6 +45,15 @@ config POWER_RESET_HISI
>  	help
>  	  Reboot support for Hisilicon boards.
>  
> +config POWER_RESET_IMX
> +	bool "IMX6 power-off driver"
> +	depends on POWER_RESET && SOC_IMX6
> +	help
> +	  This driver support power off external PMIC by PMIC_ON_REQ on i.mx6
> +	  boards.If you want to use other pin to control external power,please
> +	  say N here or disable in dts to make sure pm_power_off never be
> +	  overwrote wrongly by this driver.
> +
>  config POWER_RESET_MSM
>  	bool "Qualcomm MSM power-off driver"
>  	depends on POWER_RESET && ARCH_QCOM
> diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
> index a42e70e..2524daf 100644
> --- a/drivers/power/reset/Makefile
> +++ b/drivers/power/reset/Makefile
> @@ -3,6 +3,7 @@ obj-$(CONFIG_POWER_RESET_AXXIA) += axxia-reset.o
>  obj-$(CONFIG_POWER_RESET_BRCMSTB) += brcmstb-reboot.o
>  obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o
>  obj-$(CONFIG_POWER_RESET_HISI) += hisi-reboot.o
> +obj-$(CONFIG_POWER_RESET_IMX) += imx-snvs-poweroff.o
>  obj-$(CONFIG_POWER_RESET_MSM) += msm-poweroff.o
>  obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
>  obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o
> diff --git a/drivers/power/reset/imx-snvs-poweroff.c b/drivers/power/reset/imx-snvs-poweroff.c
> new file mode 100644
> index 0000000..d726ac4
> --- /dev/null
> +++ b/drivers/power/reset/imx-snvs-poweroff.c
> @@ -0,0 +1,66 @@
> +/* Power off driver for i.mx6
> + * Copyright (c) 2014, FREESCALE CORPORATION.  All rights reserved.
> + *
> + * based on msm-poweroff.c
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 and
> + * only version 2 as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> + * GNU General Public License for more details.
> + *
> + */
> +
> +#include <linux/err.h>
> +#include <linux/init.h>
> +#include <linux/io.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +
> +static void __iomem *snvs_base;
> +
> +static void do_imx_poweroff(void)
> +{
> +	u32 value = readl(snvs_base);
> +
> +	/* set TOP and DP_EN bit */
> +	writel(value | 0x60, snvs_base);
> +}
> +
> +static int imx_poweroff_probe(struct platform_device *pdev)
> +{
> +	snvs_base = of_iomap(pdev->dev.of_node, 0);
> +	if (!snvs_base) {
> +		dev_err(&pdev->dev, "failed to get memory\n");
> +		return -EIO;
> +	}
> +
> +	pm_power_off = do_imx_poweroff;
> +	return 0;
> +}
> +
> +static const struct of_device_id of_imx_poweroff_match[] = {
> +	{ .compatible = "fsl,sec-v4.0-poweroff", },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, of_imx_poweroff_match);
> +
> +static struct platform_driver imx_poweroff_driver = {
> +	.probe = imx_poweroff_probe,
> +	.driver = {
> +		.name = "imx-snvs-poweroff",
> +		.of_match_table = of_match_ptr(of_imx_poweroff_match),
> +	},
> +};
> +
> +static int __init imx_poweroff_init(void)
> +{
> +	return platform_driver_register(&imx_poweroff_driver);
> +}
> +device_initcall(imx_poweroff_init);
> -- 
> 1.7.9.5
> 
>