[PATCH 1/2] power: Add APM X-Gene system reboot driver

[Anton Vorontsov]

On Tue, Jul 02, 2013 at 02:38:58PM -0600, Loc Ho wrote:
> power: Add APM X-Gene SoC system reboot driver. This driver handles only
> system reboot. System shutdown is board specific and can be handled by board
> driver or GPIO based shutdown driver.
> 
> Signed-off-by: Loc Ho <lho at apm.com>
> Signed-off-by: Feng Kan <fkan at apm.com>
> Signed-off-by: Kumar Sankaran <ksankaran at apm.com>
> ---

The patch looks great, thanks for it! Just a few minor issues I noticed...

>  drivers/power/reset/Kconfig        |    7 +++
>  drivers/power/reset/Makefile       |    1 +
>  drivers/power/reset/xgene-reboot.c |  101 ++++++++++++++++++++++++++++++++++++
>  3 files changed, 109 insertions(+), 0 deletions(-)
>  create mode 100755 drivers/power/reset/xgene-reboot.c
> 
> diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig
> index 349e9ae..c41a7de 100644
> --- a/drivers/power/reset/Kconfig
> +++ b/drivers/power/reset/Kconfig
> @@ -37,3 +37,10 @@ config POWER_RESET_VEXPRESS
>  	help
>  	  Power off and reset support for the ARM Ltd. Versatile
>  	  Express boards.
> +
> +config POWER_RESET_XGENE
> +        bool
> +	default y if ARM64

This is not good. You don't want to select the driver for all ARM64
builds. I changed it to 'depends on' and made the driver optionally
selectable.

> +        depends on POWER_RESET	
> +        help
> +          Reboot support for the APM SoC X-Gene Eval boards.

Some whitespace issues here...

> diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile
> index 372807f..e75d54c 100644
> --- a/drivers/power/reset/Makefile
> +++ b/drivers/power/reset/Makefile
> @@ -2,3 +2,4 @@ obj-$(CONFIG_POWER_RESET_GPIO) += gpio-poweroff.o
>  obj-$(CONFIG_POWER_RESET_QNAP) += qnap-poweroff.o
>  obj-$(CONFIG_POWER_RESET_RESTART) += restart-poweroff.o
>  obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o
> +obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o
> diff --git a/drivers/power/reset/xgene-reboot.c b/drivers/power/reset/xgene-reboot.c
> new file mode 100755

Executable bit on the source file?..

> index 0000000..e6e4178
> --- /dev/null
> +++ b/drivers/power/reset/xgene-reboot.c
> @@ -0,0 +1,101 @@
> +/*
> + * xgene-reboot.c - AppliedMicro X-Gene SoC Reboot Driver

No need for the file name in the file itself.

> + *
> + * Copyright (c) 2013, Applied Micro Circuits Corporation
> + * Author: Feng Kan <fkan at apm.com>
> + * Author: Loc Ho <lho at apm.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.
> + *
> + * 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.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
> + * MA 02111-1307 USA
> + *
> + * This driver provides system reboot functionality for APM X-Gene SoC.
> + * For system shutdown, this is board specify. If a board designer
> + * implements GPIO shutdown, use the gpio-poweroff.c driver.
> + *
> + */
> +#include <linux/io.h>
> +#include <linux/of_device.h>
> +#include <linux/of_address.h>
> +#include <linux/platform_device.h>
> +#include <linux/stat.h>
> +#include <linux/slab.h>
> +#include <asm/system_misc.h>
> +
> +struct xgene_reboot_context {
> +	struct platform_device *pdev;
> +	void *csr;
> +	u32 mask;
> +};
> +
> +static struct xgene_reboot_context *xgene_restart_ctx;
> +
> +static void xgene_restart(char str, const char *cmd)
> +{
> +	struct xgene_reboot_context *ctx = xgene_restart_ctx;
> +	unsigned long timeout;
> +
> +	/* Issue the reboot */
> +	if (ctx)
> +		writel(ctx->mask, ctx->csr);
> +
> +	timeout = jiffies + HZ;
> +	while (time_before(jiffies, timeout))
> +		cpu_relax();
> +
> +	dev_emerg(&ctx->pdev->dev, "Unable to restart system\n");
> +}
> +
> +static int xgene_reboot_probe(struct platform_device *pdev)
> +{
> +	struct xgene_reboot_context *ctx;
> +
> +	ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
> +	if (ctx == NULL) {

!ctx is shorter

> +		dev_err(&pdev->dev, "out of memory for context\n");
> +		return -ENODEV;
> +	}
> +	ctx->csr = of_iomap(pdev->dev.of_node, 0);
> +	if (ctx->csr == NULL) {
> +		devm_kfree(&pdev->dev, ctx);
> +		dev_err(&pdev->dev, "can not map resource\n");
> +		return -ENODEV;
> +	}
> +	if (of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask))
> +		ctx->mask = 0xFFFFFFFF;
> +	ctx->pdev = pdev;
> +	arm_pm_restart = xgene_restart;
> +	xgene_restart_ctx = ctx;
> +
> +	return 0;
> +}
> +
> +static struct of_device_id xgene_reboot_of_match[] = {
> +	{ .compatible = "apm,xgene-reboot" },
> +	{}
> +};
> +
> +static struct platform_driver xgene_reboot_driver = {
> +	.probe = xgene_reboot_probe,
> +	.driver = {
> +		.name = "xgene-reboot",
> +		.of_match_table = xgene_reboot_of_match,
> +	},
> +};
> +
> +static int __init xgene_reboot_init(void)
> +{
> +	return platform_driver_register(&xgene_reboot_driver);
> +}
> +device_initcall(xgene_reboot_init);
> -- 
> 1.5.5

Wow! This is an ancient git release, 5 years old. Just saying... :)

Anyways, I fixed all the nits and applied the patch to the battery-2.6.git
tree.

Thanks!

Anton