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

[Marek Vasut]

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() ?

> +	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() ?

[...]

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.

-- 
Best regards,
Marek Vasut