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

From: chenfeng
Date: Sun Sep 13 2015 - 22:03:20 EST



On 2015/9/12 14:06, xuyiping wrote:
>
>
> 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@xxxxxxxxxxxxx>
>> ---
>> 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@xxxxxxxxxxxxx>
>> + *
>> + * 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 ?
>
Yes, I think this has already been checked at reset framework.
>> + 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);
>>
>
>
> .
>

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