Re: [PATCH V2 3/3] reset: hi6220: Reset driver for hisilicon hi6220 SoC

xuyiping
2015-09-12T06:19:30Z

On 2015/9/11 16:18, Chen Feng wrote:
> 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 | 118 +++++++++++++++++++++++++++++++++
> 5 files changed, 126 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-$(CONFIG_ARCH_HISI) += hisilicon/
> diff --git a/drivers/reset/hisilicon/Kconfig b/drivers/reset/hisilicon/Kconfig
> new file mode 100644
> index 0000000..26bf95a
> --- /dev/null
> +++ b/drivers/reset/hisilicon/Kconfig
> @@ -0,0 +1,5 @@
> +config COMMON_RESET_HI6220
> + tristate "Hi6220 Reset Driver"
> + depends on (ARCH_HISI && RESET_CONTROLLER)
> + help
> + Build the Hisilicon Hi6220 reset driver.
> diff --git a/drivers/reset/hisilicon/Makefile b/drivers/reset/hisilicon/Makefile
> new file mode 100644
> index 0000000..c932f86
> --- /dev/null
> +++ b/drivers/reset/hisilicon/Makefile
> @@ -0,0 +1 @@
> +obj-$(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..097133d
> --- /dev/null
> +++ b/drivers/reset/hisilicon/hi6220_reset.c
> @@ -0,0 +1,118 @@
> +/*
> + * 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>
> +#include <linux/sizes.h>
> +#include <linux/slab.h>
> +
> +#define ASSET_OFFSET 0x300
> +#define DEASSET_OFFSET 0x304
> +
> +struct hi6220_reset_data {
> + spinlock_t reset_lock; /*device spin-lock*/
> + void __iomem *src_base;
> + void __iomem *asset_base;
> + void __iomem *deasset_base;
> + struct reset_controller_dev rc_dev;
> +};
> +
> +static int hi6220_reset_assert(struct reset_controller_dev *rc_dev,
> + unsigned long idx)
> +{
> + struct hi6220_reset_data *data = container_of(rc_dev,
> + struct hi6220_reset_data,
> + rc_dev);
> +
> + unsigned long flags;
> + int bank = idx >> 8;
> + int offset = idx & 0xff;
> +
> + spin_lock_irqsave(&data->reset_lock, flags);

the spin_lock looks useless.

it is not a "read and write" register.

> + writel(BIT(offset), data->asset_base + (bank * 0x10));
> +
> + spin_unlock_irqrestore(&data->reset_lock, flags);
> +
> + return 0;
> +}
> +
> +static int hi6220_reset_deassert(struct reset_controller_dev *rc_dev,
> + unsigned long idx)
> +{
> + struct hi6220_reset_data *data = container_of(rc_dev,
> + struct hi6220_reset_data,
> + rc_dev);
> +
> + unsigned long flags;
> + int bank = idx >> 8;
> + int offset = idx & 0xff;

no need to check the idx scope ?

> + spin_lock_irqsave(&data->reset_lock, flags);
> +
> + writel(BIT(offset), data->deasset_base + (bank * 0x10));
> +
> + spin_unlock_irqrestore(&data->reset_lock, flags);
> +
> + return 0;
> +}
> +
> +static struct reset_control_ops hi6220_reset_ops = {
> + .assert = hi6220_reset_assert,
> + .deassert = hi6220_reset_deassert,
> +};
> +
> +static int __init hi6220_reset_init(void)
> +{
> + int ret;
> + struct device_node *np;
> + struct hi6220_reset_data *data;
> +
> + data = kzalloc(sizeof(*data), GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + np = of_find_compatible_node(NULL, NULL, "hisilicon,hi6220_reset_ctl");
> + if (!np) {
> + ret = -ENXIO;
> + goto err_alloc;
> + }
> + spin_lock_init(&data->reset_lock);
> + data->src_base = of_iomap(np, 0);
> + if (!data->src_base) {
> + ret = -ENOMEM;
> + goto err_alloc;
> + }
> +
> + data->asset_base = data->src_base + ASSET_OFFSET;
> + data->deasset_base = data->src_base + DEASSET_OFFSET;
> + data->rc_dev.owner = THIS_MODULE;
> + data->rc_dev.nr_resets = SZ_4K;
> + data->rc_dev.ops = &hi6220_reset_ops;
> + data->rc_dev.of_node = np;
> +
> + if (IS_ENABLED(CONFIG_RESET_CONTROLLER))
> + reset_controller_register(&data->rc_dev);
> +
> + return 0;
> +
> +err_alloc:

> + kfree(data);
> + return ret;
> +}
> +
> +postcore_initcall(hi6220_reset_init);
>