[PATCH v4 0/2] Driver support for RZ/V2M PWC

[PATCH v4 0/2] Driver support for RZ/V2M PWC

[Fabrizio Castro]

The PWC IP found in the RZ/V2M family of chips fits the Multi-Function
Device (MFD) model quite well, and comes with the below capabilities:
* external power supply on/off sequence generation
* on/off signal generation for the LPDDR4 core power supply (LPVDD)
* key input signals processing
* general-purpose output pins

Version 4 of this series basically just moves the dt-bindings
file under Documentation/devicetree/bindings/soc/renesas.

Thanks,
Fab
Fabrizio Castro (2):
  dt-bindings: mfd: Add RZ/V2M PWC
  soc: renesas: Add PWC support for RZ/V2M

 .../soc/renesas/renesas,rzv2m-pwc.yaml        |  56 +++++++
 drivers/soc/renesas/Kconfig                   |   4 +
 drivers/soc/renesas/Makefile                  |   1 +
 drivers/soc/renesas/pwc-rzv2m.c               | 141 ++++++++++++++++++
 4 files changed, 202 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/renesas/renesas,rzv2m-pwc.yaml
 create mode 100644 drivers/soc/renesas/pwc-rzv2m.c

-- 
2.34.1

[PATCH v4 1/2] dt-bindings: mfd: Add RZ/V2M PWC

[Fabrizio Castro]

The Renesas RZ/V2M External Power Sequence Controller (PWC)
IP is a multi-function device, and it's capable of:
* external power supply on/off sequence generation
* on/off signal generation for the LPDDR4 core power supply (LPVDD)
* key input signals processing
* general-purpose output pins

Add the corresponding dt-bindings.

Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---

v1->v2: I have dropped syscon, simple-mfd, regmap, offset, and the child nodes.
v2->v3: No change.
v3->v4: Moved file under Documentation/devicetree/bindings/soc/renesas,
        and changed $id accordingly. Rob, I have kept your Reviewed-by
        tag assuming you are still happy, please do jump in if you think
        that's not appropriate anymore.

 .../soc/renesas/renesas,rzv2m-pwc.yaml        | 56 +++++++++++++++++++
 1 file changed, 56 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/soc/renesas/renesas,rzv2m-pwc.yaml

diff --git a/Documentation/devicetree/bindings/soc/renesas/renesas,rzv2m-pwc.yaml b/Documentation/devicetree/bindings/soc/renesas/renesas,rzv2m-pwc.yaml
new file mode 100644
index 000000000000..12df33f58484
--- /dev/null
+++ b/Documentation/devicetree/bindings/soc/renesas/renesas,rzv2m-pwc.yaml
@@ -0,0 +1,56 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/soc/renesas/renesas,rzv2m-pwc.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Renesas RZ/V2M External Power Sequence Controller (PWC)
+
+description: |+
+  The PWC IP found in the RZ/V2M family of chips comes with the below
+  capabilities
+    - external power supply on/off sequence generation
+    - on/off signal generation for the LPDDR4 core power supply (LPVDD)
+    - key input signals processing
+    - general-purpose output pins
+
+maintainers:
+  - Fabrizio Castro <fabrizio.castro.jz@renesas.com>
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - renesas,r9a09g011-pwc # RZ/V2M
+          - renesas,r9a09g055-pwc # RZ/V2MA
+      - const: renesas,rzv2m-pwc
+
+  reg:
+    maxItems: 1
+
+  gpio-controller: true
+
+  '#gpio-cells':
+    const: 2
+
+  renesas,rzv2m-pwc-power:
+    description: The PWC is used to control the system power supplies.
+    type: boolean
+
+required:
+  - compatible
+  - reg
+  - gpio-controller
+  - '#gpio-cells'
+
+additionalProperties: false
+
+examples:
+  - |
+    pwc: pwc@a3700000 {
+      compatible = "renesas,r9a09g011-pwc", "renesas,rzv2m-pwc";
+      reg = <0xa3700000 0x800>;
+      gpio-controller;
+      #gpio-cells = <2>;
+      renesas,rzv2m-pwc-power;
+    };
-- 
2.34.1

[PATCH v4 2/2] soc: renesas: Add PWC support for RZ/V2M

[Fabrizio Castro]

The Renesas RZ/V2M External Power Sequence Controller (PWC)
IP is capable of:
* external power supply on/off sequence generation
* on/off signal generation for the LPDDR4 core power supply (LPVDD)
* key input signals processing
* general-purpose output pins

Add the corresponding device driver.

Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
---

v1: In the first version, I had 1 driver for GPIO handling, and 1 driver
    for poweroff handling, both based on syscon to share the mapped
    memory region.
v2: One more driver added to act as MFD core driver. Dropped syscon, and
    dropped the OF compatible string for the GPIO and poweroff drivers.
v3: This new patch merges all the PWC code in 1 new driver.
    It also takes into account the comments received from Bartosz and Geert.
    Since this is a new driver, I have dropped all the Reviewed-by tags
    received on the separated drivers.
v4: No change.

 drivers/soc/renesas/Kconfig     |   4 +
 drivers/soc/renesas/Makefile    |   1 +
 drivers/soc/renesas/pwc-rzv2m.c | 141 ++++++++++++++++++++++++++++++++
 3 files changed, 146 insertions(+)
 create mode 100644 drivers/soc/renesas/pwc-rzv2m.c

diff --git a/drivers/soc/renesas/Kconfig b/drivers/soc/renesas/Kconfig
index 660498252ec5..4e8b51ba2266 100644
--- a/drivers/soc/renesas/Kconfig
+++ b/drivers/soc/renesas/Kconfig
@@ -330,6 +330,7 @@ config ARCH_R9A09G011
 	bool "ARM64 Platform support for RZ/V2M"
 	select PM
 	select PM_GENERIC_DOMAINS
+	select PWC_RZV2M
 	help
 	  This enables support for the Renesas RZ/V2M SoC.
 
@@ -345,6 +346,9 @@ config ARCH_R9A07G043
 
 endif # RISCV
 
+config PWC_RZV2M
+	bool "Renesas RZ/V2M PWC support" if COMPILE_TEST
+
 config RST_RCAR
 	bool "Reset Controller support for R-Car" if COMPILE_TEST
 
diff --git a/drivers/soc/renesas/Makefile b/drivers/soc/renesas/Makefile
index 535868c9c7e4..6e4e77b0afff 100644
--- a/drivers/soc/renesas/Makefile
+++ b/drivers/soc/renesas/Makefile
@@ -32,6 +32,7 @@ obj-$(CONFIG_ARCH_R9A06G032)	+= r9a06g032-smp.o
 endif
 
 # Family
+obj-$(CONFIG_PWC_RZV2M)		+= pwc-rzv2m.o
 obj-$(CONFIG_RST_RCAR)		+= rcar-rst.o
 obj-$(CONFIG_SYSC_RCAR)		+= rcar-sysc.o
 obj-$(CONFIG_SYSC_RCAR_GEN4)	+= rcar-gen4-sysc.o
diff --git a/drivers/soc/renesas/pwc-rzv2m.c b/drivers/soc/renesas/pwc-rzv2m.c
new file mode 100644
index 000000000000..c83bdbdabb64
--- /dev/null
+++ b/drivers/soc/renesas/pwc-rzv2m.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 Renesas Electronics Corporation
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/driver.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+
+#define PWC_PWCRST			0x00
+#define PWC_PWCCKEN			0x04
+#define PWC_PWCCTL			0x50
+#define PWC_GPIO			0x80
+
+#define PWC_PWCRST_RSTSOFTAX		0x1
+#define PWC_PWCCKEN_ENGCKMAIN		0x1
+#define PWC_PWCCTL_PWOFF		0x1
+
+struct rzv2m_pwc_priv {
+	void __iomem *base;
+	struct device *dev;
+	struct gpio_chip gp;
+	DECLARE_BITMAP(ch_en_bits, 2);
+};
+
+static void rzv2m_pwc_gpio_set(struct gpio_chip *chip, unsigned int offset,
+			       int value)
+{
+	struct rzv2m_pwc_priv *priv = gpiochip_get_data(chip);
+	u32 reg;
+
+	/* BIT 16 enables write to BIT 0, and BIT 17 enables write to BIT 1 */
+	reg = BIT(offset + 16);
+	if (value)
+		reg |= BIT(offset);
+
+	writel(reg, priv->base + PWC_GPIO);
+
+	assign_bit(offset, priv->ch_en_bits, value);
+}
+
+static int rzv2m_pwc_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+	struct rzv2m_pwc_priv *priv = gpiochip_get_data(chip);
+
+	return test_bit(offset, priv->ch_en_bits);
+}
+
+static int rzv2m_pwc_gpio_direction_output(struct gpio_chip *gc,
+					   unsigned int nr, int value)
+{
+	if (nr > 1)
+		return -EINVAL;
+
+	rzv2m_pwc_gpio_set(gc, nr, value);
+
+	return 0;
+}
+
+static const struct gpio_chip rzv2m_pwc_gc = {
+	.label = "gpio_rzv2m_pwc",
+	.owner = THIS_MODULE,
+	.get = rzv2m_pwc_gpio_get,
+	.set = rzv2m_pwc_gpio_set,
+	.direction_output = rzv2m_pwc_gpio_direction_output,
+	.can_sleep = false,
+	.ngpio = 2,
+	.base = -1,
+};
+
+static int rzv2m_pwc_poweroff(struct sys_off_data *data)
+{
+	struct rzv2m_pwc_priv *priv = data->cb_data;
+
+	writel(PWC_PWCRST_RSTSOFTAX, priv->base + PWC_PWCRST);
+	writel(PWC_PWCCKEN_ENGCKMAIN, priv->base + PWC_PWCCKEN);
+	writel(PWC_PWCCTL_PWOFF, priv->base + PWC_PWCCTL);
+
+	mdelay(150);
+
+	dev_err(priv->dev, "Failed to power off the system");
+
+	return NOTIFY_DONE;
+}
+
+static int rzv2m_pwc_probe(struct platform_device *pdev)
+{
+	struct rzv2m_pwc_priv *priv;
+	int ret;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base))
+		return PTR_ERR(priv->base);
+
+	/*
+	 * The register used by this driver cannot be read, therefore set the
+	 * outputs to their default values and initialize priv->ch_en_bits
+	 * accordingly. BIT 16 enables write to BIT 0, BIT 17 enables write to
+	 * BIT 1, and the default value of both BIT 0 and BIT 1 is 0.
+	 */
+	writel(BIT(17) | BIT(16), priv->base + PWC_GPIO);
+	bitmap_zero(priv->ch_en_bits, 2);
+
+	priv->gp = rzv2m_pwc_gc;
+	priv->gp.parent = pdev->dev.parent;
+	priv->gp.fwnode = dev_fwnode(&pdev->dev);
+
+	ret = devm_gpiochip_add_data(&pdev->dev, &priv->gp, priv);
+	if (ret)
+		return ret;
+
+	if (device_property_read_bool(&pdev->dev, "renesas,rzv2m-pwc-power"))
+		ret = devm_register_power_off_handler(&pdev->dev,
+						      rzv2m_pwc_poweroff, priv);
+
+	return ret;
+}
+
+static const struct of_device_id rzv2m_pwc_of_match[] = {
+	{ .compatible = "renesas,rzv2m-pwc" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, rzv2m_pwc_of_match);
+
+static struct platform_driver rzv2m_pwc_driver = {
+	.probe = rzv2m_pwc_probe,
+	.driver = {
+		.name = "rzv2m_pwc",
+		.of_match_table = of_match_ptr(rzv2m_pwc_of_match),
+	},
+};
+module_platform_driver(rzv2m_pwc_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Fabrizio Castro <castro.fabrizio.jz@renesas.com>");
+MODULE_DESCRIPTION("Renesas RZ/V2M PWC driver");
-- 
2.34.1

Re: [PATCH v4 1/2] dt-bindings: mfd: Add RZ/V2M PWC

[Lee Jones]

On Thu, 05 Jan 2023, Fabrizio Castro wrote:

> The Renesas RZ/V2M External Power Sequence Controller (PWC)
> IP is a multi-function device, and it's capable of:
> * external power supply on/off sequence generation
> * on/off signal generation for the LPDDR4 core power supply (LPVDD)
> * key input signals processing
> * general-purpose output pins

The subject line now needs changing.

This patch doesn't have anything to do with MFD.

> Add the corresponding dt-bindings.
> 
> Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
> Reviewed-by: Rob Herring <robh@kernel.org>
> ---
> 
> v1->v2: I have dropped syscon, simple-mfd, regmap, offset, and the child nodes.
> v2->v3: No change.
> v3->v4: Moved file under Documentation/devicetree/bindings/soc/renesas,
>         and changed $id accordingly. Rob, I have kept your Reviewed-by
>         tag assuming you are still happy, please do jump in if you think
>         that's not appropriate anymore.
> 
>  .../soc/renesas/renesas,rzv2m-pwc.yaml        | 56 +++++++++++++++++++
>  1 file changed, 56 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/soc/renesas/renesas,rzv2m-pwc.yaml

-- 
Lee Jones [李琼斯]

RE: [PATCH v4 1/2] dt-bindings: mfd: Add RZ/V2M PWC

[Fabrizio Castro]

Hi Lee,

Thanks for your feedback!

> 
> On Thu, 05 Jan 2023, Fabrizio Castro wrote:
> 
> > The Renesas RZ/V2M External Power Sequence Controller (PWC)
> > IP is a multi-function device, and it's capable of:
> > * external power supply on/off sequence generation
> > * on/off signal generation for the LPDDR4 core power supply (LPVDD)
> > * key input signals processing
> > * general-purpose output pins
> 
> The subject line now needs changing.
> 
> This patch doesn't have anything to do with MFD.

Doh, you are absolutely right, I'll send a v5 to address that.

Thanks,
Fab

> 
> > Add the corresponding dt-bindings.
> >
> > Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
> > Reviewed-by: Rob Herring <robh@kernel.org>
> > ---
> >
> > v1->v2: I have dropped syscon, simple-mfd, regmap, offset, and the child
> nodes.
> > v2->v3: No change.
> > v3->v4: Moved file under Documentation/devicetree/bindings/soc/renesas,
> >         and changed $id accordingly. Rob, I have kept your Reviewed-by
> >         tag assuming you are still happy, please do jump in if you think
> >         that's not appropriate anymore.
> >
> >  .../soc/renesas/renesas,rzv2m-pwc.yaml        | 56 +++++++++++++++++++
> >  1 file changed, 56 insertions(+)
> >  create mode 100644
> Documentation/devicetree/bindings/soc/renesas/renesas,rzv2m-pwc.yaml
> 
> --
> Lee Jones [李琼斯]