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

[chenfeng]

Zabel,
Thanks for review.


On 2015/9/10 17:40, Philipp Zabel wrote:
> 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@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 | 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@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>
>> +
>> +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.
> 

Totally agree!

>> +	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
> 
> 
> .
> 

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