[U-Boot] [PATCH] reset: socfpga: add reset driver for SoCFPGA platform

[Dinh Nguyen]

On 03/30/2018 02:45 PM, Marek Vasut wrote:
> On 03/30/2018 06:53 PM, Dinh Nguyen wrote:
>> Add a DM compatible reset driver for the SoCFPGA platform.
>>
>> Signed-off-by: Dinh Nguyen <dinguyen at kernel.org>
>> ---
>>  drivers/reset/Kconfig         |   7 +++
>>  drivers/reset/Makefile        |   1 +
>>  drivers/reset/reset-socfpga.c | 111 ++++++++++++++++++++++++++++++++++++++++++
>>  3 files changed, 119 insertions(+)
>>  create mode 100644 drivers/reset/reset-socfpga.c
>>
>> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
>> index 3964b9e..90b021f 100644
>> --- a/drivers/reset/Kconfig
>> +++ b/drivers/reset/Kconfig
>> @@ -83,4 +83,11 @@ config RESET_ROCKCHIP
>>  	  though is that some reset signals, like I2C or MISC reset multiple
>>  	  devices.
>>  
>> +config RESET_SOCFPGA
>> +	bool "Reset controller driver for SoCFPGA"
>> +	depends on DM_RESET && ARCH_SOCFPGA
>> +	default y
>> +	help
>> +	  Support for reset controller on SoCFPGA platform.
>> +
>>  endmenu
>> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
>> index 7d7e080..6f791ee 100644
>> --- a/drivers/reset/Makefile
>> +++ b/drivers/reset/Makefile
>> @@ -13,3 +13,4 @@ obj-$(CONFIG_RESET_BCM6345) += reset-bcm6345.o
>>  obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
>>  obj-$(CONFIG_AST2500_RESET) += ast2500-reset.o
>>  obj-$(CONFIG_RESET_ROCKCHIP) += reset-rockchip.o
>> +obj-$(CONFIG_RESET_SOCFPGA) += reset-socfpga.o
>> diff --git a/drivers/reset/reset-socfpga.c b/drivers/reset/reset-socfpga.c
>> new file mode 100644
>> index 0000000..af585ec
>> --- /dev/null
>> +++ b/drivers/reset/reset-socfpga.c
>> @@ -0,0 +1,111 @@
>> +/*
>> + * Socfpga Reset Controller Driver
>> + *
>> + * Copyright 2014 Steffen Trumtrar <s.trumtrar at pengutronix.de>
>> + *
>> + * based on
>> + * Allwinner SoCs Reset Controller driver
>> + *
>> + * Copyright 2013 Maxime Ripard
>> + *
>> + * Maxime Ripard <maxime.ripard at free-electrons.com>
>> + *
>> + * SPDX-License-Identifier:     GPL-2.0+
>> + */
>> +
>> +#include <common.h>
>> +#include <dm.h>
>> +#include <dm/of_access.h>
>> +#include <reset-uclass.h>
>> +#include <linux/bitops.h>
>> +#include <linux/io.h>
>> +#include <linux/sizes.h>
>> +
>> +#define BANK_INCREMENT		4
>> +#define NR_BANKS		8
>> +
>> +struct socfpga_reset_data {
>> +	void __iomem *membase;
>> +};
>> +
>> +static int socfpga_reset_assert(struct reset_ctl *reset_ctl)
>> +{
>> +	struct socfpga_reset_data *data = dev_get_priv(reset_ctl->dev);
>> +	int id = reset_ctl->id;
>> +	int reg_width = sizeof(u32);
>> +	int bank = id / (reg_width * BITS_PER_BYTE);
>> +	int offset = id % (reg_width * BITS_PER_BYTE);
>> +	unsigned long flags;
>> +	u32 reg;
>> +
>> +	reg = readl(data->membase + (bank * BANK_INCREMENT));
>> +	writel(reg | BIT(offset), data->membase + (bank * BANK_INCREMENT));
> 
> setbits_le32() ?
> 

Ok..

>> +	return 0;
>> +}
>> +
>> +static int socfpga_reset_deassert(struct reset_ctl *reset_ctl)
>> +{
>> +	struct socfpga_reset_data *data = dev_get_priv(reset_ctl->dev);
>> +	int id = reset_ctl->id;
>> +	int reg_width = sizeof(u32);
>> +	int bank = id / (reg_width * BITS_PER_BYTE);
>> +	int offset = id % (reg_width * BITS_PER_BYTE);
>> +	unsigned long flags;
>> +	u32 reg;
>> +
>> +	reg = readl(data->membase + (bank * BANK_INCREMENT));
>> +	writel(reg & ~BIT(offset), data->membase + (bank * BANK_INCREMENT));
> 
> clrbits_le32() ?
> 

Ok..

> [...]
> 
> What I do not see is any user of this code, nor any conversion of
> existing systems to use this code. Is that expected to happen ? I do not
> want to see dead code piling up in U-Boot.
> 

I have a patchset that tested this code, the i2c support in SoCFPGA was
converted to DM, and uses this reset framework. Should I send that along
with this patch in v2?

Dinh