[PATCH v2 0/2] reset: Add Broadcom STB SW_INIT reset controller driver

[PATCH v2 0/2] reset: Add Broadcom STB SW_INIT reset controller driver

[Florian Fainelli]

Hi Philipp,

This patch series adds support for the Broadcom STB reset controller
using SW_INIT-style registers which have one or more banks of 32
reset lines and separate CLEAR/SET/STATUS registers.

Thanks!

Changes in v2:

- utilize SW_INIT_BIT() in status callback
- removed unused members of private structure
- confirmed maximum reset duration with designers
- renamed binding to brcm,brcmstb-reset.txt


Florian Fainelli (2):
  dt-bindings: reset: Add document for Broadcom STB reset controller
  reset: Add Broadcom STB SW_INIT reset controller driver

 .../bindings/reset/brcm,brcmstb-reset.txt     |  27 ++++
 drivers/reset/Kconfig                         |   7 +
 drivers/reset/Makefile                        |   1 +
 drivers/reset/reset-brcmstb.c                 | 130 ++++++++++++++++++
 4 files changed, 165 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reset/brcm,brcmstb-reset.txt
 create mode 100644 drivers/reset/reset-brcmstb.c

-- 
2.17.1

[PATCH v2 1/2] dt-bindings: reset: Add document for Broadcom STB reset controller

[Florian Fainelli]

Add a binding document for the Broadcom STB reset controller, also known
as SW_INIT-style reset controller.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
 .../bindings/reset/brcm,brcmstb-reset.txt     | 27 +++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reset/brcm,brcmstb-reset.txt

diff --git a/Documentation/devicetree/bindings/reset/brcm,brcmstb-reset.txt b/Documentation/devicetree/bindings/reset/brcm,brcmstb-reset.txt
new file mode 100644
index 000000000000..6e5341b4f891
--- /dev/null
+++ b/Documentation/devicetree/bindings/reset/brcm,brcmstb-reset.txt
@@ -0,0 +1,27 @@
+Broadcom STB SW_INIT-style reset controller
+===========================================
+
+Broadcom STB SoCs have a SW_INIT-style reset controller with separate
+SET/CLEAR/STATUS registers and possibly multiple banks, each of 32 bit
+reset lines.
+
+Please also refer to reset.txt in this directory for common reset
+controller binding usage.
+
+Required properties:
+- compatible: should be brcm,brcmstb-reset
+- reg: register base and length
+- #reset-cells: must be set to 1
+
+Example:
+
+	reset: reset-controller@8404318 {
+		compatible = "brcm,brcmstb-reset";
+		reg = <0x8404318 0x30>;
+		#reset-cells = <1>;
+	};
+
+	&ethernet_switch {
+		resets = <&reset>;
+		reset-names = "switch";
+	};
-- 
2.17.1

[PATCH v2 2/2] reset: Add Broadcom STB SW_INIT reset controller driver

[Florian Fainelli]

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@gmail.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
+	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@gmail.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");
-- 
2.17.1

Re: [PATCH v2 2/2] reset: Add Broadcom STB SW_INIT reset controller driver

[Scott Branden]

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@gmail.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@gmail.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");

Re: [PATCH v2 1/2] dt-bindings: reset: Add document for Broadcom STB reset controller

[Rob Herring]

On Tue, 15 Jan 2019 10:44:05 -0800, Florian Fainelli wrote:
> Add a binding document for the Broadcom STB reset controller, also known
> as SW_INIT-style reset controller.
> 
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
> ---
>  .../bindings/reset/brcm,brcmstb-reset.txt     | 27 +++++++++++++++++++
>  1 file changed, 27 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/reset/brcm,brcmstb-reset.txt
> 

Reviewed-by: Rob Herring <robh@kernel.org>

Re: [PATCH v2 1/2] dt-bindings: reset: Add document for Broadcom STB reset controller

[Philipp Zabel]

Hi Florian,

On Tue, 2019-01-15 at 10:44 -0800, Florian Fainelli wrote:
> Add a binding document for the Broadcom STB reset controller, also known
> as SW_INIT-style reset controller.
> 
> Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

Thank you, both applied to reset/next.

regards
Philipp

Re: [PATCH v2 2/2] reset: Add Broadcom STB SW_INIT reset controller driver

[Philipp Zabel]

Hi Scott,

On Wed, 2019-01-16 at 10:15 -0800, Scott Branden wrote:
> 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@gmail.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

I don't think this is necessary. Since the symbol is non-interactive if
COMPILE_TEST is disabled, it just vanishes when both are disabled.

> > +	default ARCH_BRCMSTB

And if it is actually needed, it defaults to the correct value.

regards
Philipp