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Message-ID: <7bc8d9ee-5be1-1765-55dd-b7407cff962f@broadcom.com>
Date: Wed, 16 Jan 2019 10:15:01 -0800
From: Scott Branden <scott.branden@...adcom.com>
To: Florian Fainelli <f.fainelli@...il.com>,
linux-kernel@...r.kernel.org
Cc: Philipp Zabel <p.zabel@...gutronix.de>,
Rob Herring <robh+dt@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Brian Norris <computersforpeace@...il.com>,
Gregory Fong <gregory.0xf0@...il.com>,
"maintainer:BROADCOM BCM7XXX ARM ARCHITECTURE"
<bcm-kernel-feedback-list@...adcom.com>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@...r.kernel.org>,
"moderated list:BROADCOM BCM7XXX ARM ARCHITECTURE"
<linux-arm-kernel@...ts.infradead.org>
Subject: Re: [PATCH v2 2/2] reset: Add Broadcom STB SW_INIT reset controller
driver
On 2019-01-15 10:44 a.m., Florian Fainelli wrote:
> Add support for resetting blocks through the Linux reset controller
> subsystem when reset lines are provided through a SW_INIT-style reset
> controller on Broadcom STB SoCs.
>
> Signed-off-by: Florian Fainelli <f.fainelli@...il.com>
> ---
> drivers/reset/Kconfig | 7 ++
> drivers/reset/Makefile | 1 +
> drivers/reset/reset-brcmstb.c | 130 ++++++++++++++++++++++++++++++++++
> 3 files changed, 138 insertions(+)
> create mode 100644 drivers/reset/reset-brcmstb.c
>
> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> index 2e01bd833ffd..1ca03c57e049 100644
> --- a/drivers/reset/Kconfig
> +++ b/drivers/reset/Kconfig
> @@ -40,6 +40,13 @@ config RESET_BERLIN
> help
> This enables the reset controller driver for Marvell Berlin SoCs.
>
> +config RESET_BRCMSTB
> + bool "Broadcom STB reset controller" if COMPILE_TEST
Could this even be:
depends on ARCH_BRCMSTB || COMPILE_TEST
> + default ARCH_BRCMSTB
> + help
> + This enables the reset controller driver for Broadcom STB SoCs using
> + a SUN_TOP_CTRL_SW_INIT style controller.
> +
> config RESET_HSDK
> bool "Synopsys HSDK Reset Driver"
> depends on HAS_IOMEM
> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
> index dc7874df78d9..7395db2cb1dd 100644
> --- a/drivers/reset/Makefile
> +++ b/drivers/reset/Makefile
> @@ -7,6 +7,7 @@ obj-$(CONFIG_RESET_A10SR) += reset-a10sr.o
> obj-$(CONFIG_RESET_ATH79) += reset-ath79.o
> obj-$(CONFIG_RESET_AXS10X) += reset-axs10x.o
> obj-$(CONFIG_RESET_BERLIN) += reset-berlin.o
> +obj-$(CONFIG_RESET_BRCMSTB) += reset-brcmstb.o
> obj-$(CONFIG_RESET_HSDK) += reset-hsdk.o
> obj-$(CONFIG_RESET_IMX7) += reset-imx7.o
> obj-$(CONFIG_RESET_LANTIQ) += reset-lantiq.o
> diff --git a/drivers/reset/reset-brcmstb.c b/drivers/reset/reset-brcmstb.c
> new file mode 100644
> index 000000000000..01ab1f71518b
> --- /dev/null
> +++ b/drivers/reset/reset-brcmstb.c
> @@ -0,0 +1,130 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Broadcom STB generic reset controller for SW_INIT style reset controller
> + *
> + * Author: Florian Fainelli <f.fainelli@...il.com>
> + * Copyright (C) 2018 Broadcom
> + */
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/io.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/reset-controller.h>
> +#include <linux/types.h>
> +
> +struct brcmstb_reset {
> + void __iomem *base;
> + struct reset_controller_dev rcdev;
> +};
> +
> +#define SW_INIT_SET 0x00
> +#define SW_INIT_CLEAR 0x04
> +#define SW_INIT_STATUS 0x08
> +
> +#define SW_INIT_BIT(id) BIT((id) & 0x1f)
> +#define SW_INIT_BANK(id) ((id) >> 5)
> +
> +/* A full bank contains extra registers that we are not utilizing but still
> + * qualify as a single bank.
> + */
> +#define SW_INIT_BANK_SIZE 0x18
> +
> +static inline
> +struct brcmstb_reset *to_brcmstb(struct reset_controller_dev *rcdev)
> +{
> + return container_of(rcdev, struct brcmstb_reset, rcdev);
> +}
> +
> +static int brcmstb_reset_assert(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + unsigned int off = SW_INIT_BANK(id) * SW_INIT_BANK_SIZE;
> + struct brcmstb_reset *priv = to_brcmstb(rcdev);
> +
> + writel_relaxed(SW_INIT_BIT(id), priv->base + off + SW_INIT_SET);
> +
> + return 0;
> +}
> +
> +static int brcmstb_reset_deassert(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + unsigned int off = SW_INIT_BANK(id) * SW_INIT_BANK_SIZE;
> + struct brcmstb_reset *priv = to_brcmstb(rcdev);
> +
> + writel_relaxed(SW_INIT_BIT(id), priv->base + off + SW_INIT_CLEAR);
> + /* Maximum reset delay after de-asserting a line and seeing block
> + * operation is typically 14us for the worst case, build some slack
> + * here.
> + */
> + usleep_range(100, 200);
> +
> + return 0;
> +}
> +
> +static int brcmstb_reset_status(struct reset_controller_dev *rcdev,
> + unsigned long id)
> +{
> + unsigned int off = SW_INIT_BANK(id) * SW_INIT_BANK_SIZE;
> + struct brcmstb_reset *priv = to_brcmstb(rcdev);
> +
> + return readl_relaxed(priv->base + off + SW_INIT_STATUS) &
> + SW_INIT_BIT(id);
> +}
> +
> +static const struct reset_control_ops brcmstb_reset_ops = {
> + .assert = brcmstb_reset_assert,
> + .deassert = brcmstb_reset_deassert,
> + .status = brcmstb_reset_status,
> +};
> +
> +static int brcmstb_reset_probe(struct platform_device *pdev)
> +{
> + struct device *kdev = &pdev->dev;
> + struct brcmstb_reset *priv;
> + struct resource *res;
> +
> + priv = devm_kzalloc(kdev, sizeof(*priv), GFP_KERNEL);
> + if (!priv)
> + return -ENOMEM;
> +
> + res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> + if (resource_size(res) % SW_INIT_BANK_SIZE) {
> + dev_err(kdev, "incorrect register range\n");
> + return -EINVAL;
> + }
> +
> + priv->base = devm_ioremap_resource(kdev, res);
> + if (IS_ERR(priv->base))
> + return PTR_ERR(priv->base);
> +
> + dev_set_drvdata(kdev, priv);
> +
> + priv->rcdev.owner = THIS_MODULE;
> + priv->rcdev.nr_resets = (resource_size(res) / SW_INIT_BANK_SIZE) * 32;
> + priv->rcdev.ops = &brcmstb_reset_ops;
> + priv->rcdev.of_node = kdev->of_node;
> + /* Use defaults: 1 cell and simple xlate function */
> +
> + return devm_reset_controller_register(kdev, &priv->rcdev);
> +}
> +
> +static const struct of_device_id brcmstb_reset_of_match[] = {
> + { .compatible = "brcm,brcmstb-reset" },
> + { /* sentinel */ }
> +};
> +
> +static struct platform_driver brcmstb_reset_driver = {
> + .probe = brcmstb_reset_probe,
> + .driver = {
> + .name = "brcmstb-reset",
> + .of_match_table = brcmstb_reset_of_match,
> + },
> +};
> +module_platform_driver(brcmstb_reset_driver);
> +
> +MODULE_AUTHOR("Broadcom");
> +MODULE_DESCRIPTION("Broadcom STB reset controller");
> +MODULE_LICENSE("GPL");
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