Re: [RESEND PATCH 3/3] reset: hi6220: Reset driver for hisilicon hi6220 SoC

[Philipp Zabel <p.zabel@pengutronix.de>]

Am Donnerstag, den 10.09.2015, 14:11 +0800 schrieb Chen Feng:
> Add reset driver for hi6220-hikey board,this driver supply deassert
> of IP. on hi6220 SoC.
> 
> Signed-off-by: Chen Feng <puck.chen@hisilicon.com>
> ---
>  drivers/reset/Kconfig                  |  1 +
>  drivers/reset/Makefile                 |  1 +
>  drivers/reset/hisilicon/Kconfig        |  5 +++
>  drivers/reset/hisilicon/Makefile       |  1 +
>  drivers/reset/hisilicon/hi6220_reset.c | 74 ++++++++++++++++++++++++++++++++++
>  5 files changed, 82 insertions(+)
>  create mode 100644 drivers/reset/hisilicon/Kconfig
>  create mode 100644 drivers/reset/hisilicon/Makefile
>  create mode 100644 drivers/reset/hisilicon/hi6220_reset.c
> 
> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> index 0615f50..df37212 100644
> --- a/drivers/reset/Kconfig
> +++ b/drivers/reset/Kconfig
> @@ -13,3 +13,4 @@ menuconfig RESET_CONTROLLER
>  	  If unsure, say no.
>  
>  source "drivers/reset/sti/Kconfig"
> +source "drivers/reset/hisilicon/Kconfig"
> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
> index 157d421..331d7b2 100644
> --- a/drivers/reset/Makefile
> +++ b/drivers/reset/Makefile
> @@ -3,3 +3,4 @@ obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o
>  obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o
>  obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o
>  obj-$(CONFIG_ARCH_STI) += sti/
> +obj-$(CONFIG_ARCH_HISI) += hisilicon/
> diff --git a/drivers/reset/hisilicon/Kconfig b/drivers/reset/hisilicon/Kconfig
> new file mode 100644
> index 0000000..bceed14
> --- /dev/null
> +++ b/drivers/reset/hisilicon/Kconfig
> @@ -0,0 +1,5 @@
> +config COMMON_RESET_HI6220
> +	tristate "Hi6220 Clock Driver"

"Clock"? Should probably be "Reset".

> +	depends on (ARCH_HISI && RESET_CONTROLLER)
> +	help
> +	  Build the Hisilicon Hi6220 reset driver.
> diff --git a/drivers/reset/hisilicon/Makefile b/drivers/reset/hisilicon/Makefile
> new file mode 100644
> index 0000000..c932f86
> --- /dev/null
> +++ b/drivers/reset/hisilicon/Makefile
> @@ -0,0 +1 @@
> +obj-$(CONFIG_COMMON_RESET_HI6220) += hi6220_reset.o
> diff --git a/drivers/reset/hisilicon/hi6220_reset.c b/drivers/reset/hisilicon/hi6220_reset.c
> new file mode 100644
> index 0000000..a88fc57
> --- /dev/null
> +++ b/drivers/reset/hisilicon/hi6220_reset.c
> @@ -0,0 +1,74 @@
> +/*
> + * Hisilicon Hi6220 reset controller driver
> + *
> + * Copyright (c) 2015 Hisilicon Limited.
> + *
> + * Author: Feng Chen <puck.chen@hisilicon.com>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#include <linux/init.h>
> +#include <linux/bitops.h>
> +#include <linux/io.h>
> +#include <linux/of.h>
> +#include <linux/of_address.h>
> +#include <linux/reset-controller.h>
> +#include <linux/reset.h>
> +
> +static void __iomem *src_base;
> +static DEFINE_SPINLOCK(reset_lock);
> +
> +static int hi6220_reset_module(struct reset_controller_dev *rc_dev,
> +		unsigned long idx)
> +{
> +	unsigned long timeout;
> +	unsigned long flags;
> +	int bit;
> +	u32 val;
> +
> +	int bank = idx >> 8;
> +	int offset = idx & 0xff;
> +
> +	spin_lock_irqsave(&reset_lock, flags);
> +
> +	val = readl(src_base + (bank * 0x10));
> +	writel(val | BIT(offset), src_base + (bank * 0x10));

Are these registers write-once, otherwise any reason not to implement
reset_assert, too?

> +	spin_unlock_irqrestore(&reset_lock, flags);
> +
> +	return 0;
> +
> +}
> +
> +static struct reset_control_ops hi6220_reset_ops = {
> +	.deassert = hi6220_reset_module,
> +};
> +
> +static struct reset_controller_dev hi6220_reset_dev = {
> +	.ops = &hi6220_reset_ops,
> +	.nr_resets = 0xffff,

This can't be correct, you only have 4 KiB register space.

> +};
> +
> +static void __init hi6220_reset_init(void)
> +{
> +	struct device_node *np;
> +	struct reset_control *test = NULL;
> +
> +	np = of_find_compatible_node(NULL, NULL, "hisilicon,hisi_reset_ctl");

Better use "hisilicon,hi6220-reset-ctl" instead.

> +	if (!np) {
> +		pr_err("find reset node in dts error!\n");
> +		return;
> +	}
> +	src_base = of_iomap(np, 0);
> +	WARN_ON(!src_base);
> +
> +	hi6220_reset_dev.of_node = np;
> +	if (IS_ENABLED(CONFIG_RESET_CONTROLLER))
> +		reset_controller_register(&hi6220_reset_dev);
> +}
> +
> +postcore_initcall(hi6220_reset_init);
> +

Drop this empty line.

best regards
Philipp