[PATCH 1/2] dt-bindings: reset: Add TPS380x documentation

[PATCH 1/2] dt-bindings: reset: Add TPS380x documentation

[Marco Felsch]

Add device-tree binding documentation for the tps380x reset driver. The
binding uses enum to make it easy to add more devices from that family.

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
 .../bindings/reset/ti,tps380x-reset.yaml      | 49 +++++++++++++++++++
 1 file changed, 49 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/reset/ti,tps380x-reset.yaml

diff --git a/Documentation/devicetree/bindings/reset/ti,tps380x-reset.yaml b/Documentation/devicetree/bindings/reset/ti,tps380x-reset.yaml
new file mode 100644
index 000000000000..afc835eda0ef
--- /dev/null
+++ b/Documentation/devicetree/bindings/reset/ti,tps380x-reset.yaml
@@ -0,0 +1,49 @@
+# SPDX-License-Identifier: (GPL-2.0-only or BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/reset/ti,tps380x-reset.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: TI TPS380x reset controller node bindings
+
+maintainers:
+  - Marco Felsch <kernel@pengutronix.de>
+
+description: |
+  The TPS380x family [1] of supervisory circuits monitor supply voltages to
+  provide circuit initialization and timing supervision. The devices assert a
+  RESET signal if the voltage drops below a preset threshold or upon a manual
+  reset input (MR). The RESET output remains asserted for the factory
+  programmed delay after the voltage return above its threshold or after the
+  manual reset input is released.
+
+  [1] https://www.ti.com/product/TPS3801
+
+properties:
+  compatible:
+    enum:
+      - ti,tps3801
+
+  reset-gpios:
+    maxItems: 1
+    description: Reference to the GPIO connected to the MR pin.
+
+  "#reset-cells":
+    const: 0
+
+required:
+  - compatible
+  - reset-gpios
+  - "#reset-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    reset: reset-controller {
+        compatible = "ti,tps3801";
+        #reset-cells = <0>;
+        reset-gpios = <&gpio3 2 GPIO_ACTIVE_LOW>;
+    };
+...
-- 
2.30.2

[PATCH 2/2] reset: tps380x: Add TPS380x device driver supprt

[Marco Felsch]

The TI TPS380x family [1] is a volatage supervisor with a dedicated
manual reset (mr) line input and a reset output. The chip(s) have a
build in reset delay, depending on the chip partnumber. This simple
driver addresses this so the cosumer don't need to care about it.

[1] https://www.ti.com/product/TPS3801

Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
---
 drivers/reset/Kconfig         |   8 +++
 drivers/reset/Makefile        |   1 +
 drivers/reset/reset-tps380x.c | 130 ++++++++++++++++++++++++++++++++++
 3 files changed, 139 insertions(+)
 create mode 100644 drivers/reset/reset-tps380x.c

diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
index e0fc80e041ea..e2eb616af812 100644
--- a/drivers/reset/Kconfig
+++ b/drivers/reset/Kconfig
@@ -256,6 +256,14 @@ config RESET_TI_SYSCON
 	  you wish to use the reset framework for such memory-mapped devices,
 	  say Y here. Otherwise, say N.
 
+config RESET_TI_TPS380X
+	tristate "TI TPS380x Reset Driver"
+	select GPIOLIB
+	help
+	  This enables the reset driver support for TI TPS380x devices. If
+	  you wish to use the reset framework for such devices, say Y here.
+	  Otherwise, say N.
+
 config RESET_TN48M_CPLD
 	tristate "Delta Networks TN48M switch CPLD reset controller"
 	depends on MFD_TN48M_CPLD || COMPILE_TEST
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
index a80a9c4008a7..66399b92b1bb 100644
--- a/drivers/reset/Makefile
+++ b/drivers/reset/Makefile
@@ -33,6 +33,7 @@ obj-$(CONFIG_RESET_STARFIVE_JH7100) += reset-starfive-jh7100.o
 obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
 obj-$(CONFIG_RESET_TI_SCI) += reset-ti-sci.o
 obj-$(CONFIG_RESET_TI_SYSCON) += reset-ti-syscon.o
+obj-$(CONFIG_RESET_TI_TPS380X) += reset-tps380x.o
 obj-$(CONFIG_RESET_TN48M_CPLD) += reset-tn48m.o
 obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
 obj-$(CONFIG_RESET_UNIPHIER_GLUE) += reset-uniphier-glue.o
diff --git a/drivers/reset/reset-tps380x.c b/drivers/reset/reset-tps380x.c
new file mode 100644
index 000000000000..fd2c0929ae2d
--- /dev/null
+++ b/drivers/reset/reset-tps380x.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * TI TPS380x Supply Voltage Supervisor and Reset Controller Driver
+ *
+ * Copyright (C) 2022 Pengutronix, Marco Felsch <kernel@pengutronix.de>
+ *
+ * Based on Simple Reset Controller Driver
+ *
+ * Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de>
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/reset-controller.h>
+
+struct tps380x_reset {
+	struct reset_controller_dev	rcdev;
+	struct gpio_desc		*reset_gpio;
+	unsigned int			reset_ms;
+};
+
+struct tps380x_reset_devdata {
+	unsigned int min_reset_ms;
+	unsigned int typ_reset_ms;
+	unsigned int max_reset_ms;
+};
+
+static inline
+struct tps380x_reset *to_tps380x_reset(struct reset_controller_dev *rcdev)
+{
+	return container_of(rcdev, struct tps380x_reset, rcdev);
+}
+
+static int
+tps380x_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	struct tps380x_reset *tps380x = to_tps380x_reset(rcdev);
+
+	gpiod_set_value_cansleep(tps380x->reset_gpio, 1);
+
+	return 0;
+}
+
+static int
+tps380x_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	struct tps380x_reset *tps380x = to_tps380x_reset(rcdev);
+
+	gpiod_set_value_cansleep(tps380x->reset_gpio, 0);
+	msleep(tps380x->reset_ms);
+
+	return 0;
+}
+
+const struct reset_control_ops reset_tps380x_ops = {
+	.assert		= tps380x_reset_assert,
+	.deassert	= tps380x_reset_deassert,
+};
+
+static int tps380x_reset_of_xlate(struct reset_controller_dev *rcdev,
+				  const struct of_phandle_args *reset_spec)
+{
+	/* No special handling needed, we have only one reset line per device */
+	return 0;
+}
+
+static int tps380x_reset_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	const struct tps380x_reset_devdata *devdata;
+	struct tps380x_reset *tps380x;
+
+	devdata = device_get_match_data(dev);
+	if (!devdata)
+		return -EINVAL;
+
+	tps380x = devm_kzalloc(dev, sizeof(*tps380x), GFP_KERNEL);
+	if (!tps380x)
+		return -ENOMEM;
+
+	tps380x->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(tps380x->reset_gpio))
+		return dev_err_probe(dev, PTR_ERR(tps380x->reset_gpio),
+				     "Failed to get GPIO\n");
+
+	/*
+	 * Todo:
+	 * Add firmware handling to switch between min/typ/max reset time
+	 */
+	tps380x->reset_ms = devdata->max_reset_ms;
+
+	tps380x->rcdev.ops = &reset_tps380x_ops;
+	tps380x->rcdev.owner = THIS_MODULE;
+	tps380x->rcdev.dev = dev;
+	tps380x->rcdev.of_node = dev->of_node;
+	tps380x->rcdev.of_reset_n_cells = 0;
+	tps380x->rcdev.of_xlate = tps380x_reset_of_xlate;
+	tps380x->rcdev.nr_resets = 1;
+
+	return devm_reset_controller_register(dev, &tps380x->rcdev);
+}
+
+static const struct tps380x_reset_devdata tps3801_reset_data = {
+	.min_reset_ms = 120,
+	.typ_reset_ms = 200,
+	.max_reset_ms = 280,
+};
+
+static const struct of_device_id tps380x_reset_dt_ids[] = {
+	{ .compatible = "ti,tps3801", .data = &tps3801_reset_data },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, tps380x_reset_dt_ids);
+
+static struct platform_driver tps380x_reset_driver = {
+	.probe	= tps380x_reset_probe,
+	.driver = {
+		.name		= "tps380x-reset",
+		.of_match_table	= tps380x_reset_dt_ids,
+	},
+};
+module_platform_driver(tps380x_reset_driver);
+
+MODULE_AUTHOR("Marco Felsch <kernel@pengutronix.de>");
+MODULE_DESCRIPTION("TI TPS380x Supply Voltags Supervisor and Reset Driver");
+MODULE_LICENSE("GPL v2");
-- 
2.30.2

Re: [PATCH 1/2] dt-bindings: reset: Add TPS380x documentation

[Krzysztof Kozlowski]

On 25/05/2022 16:20, Marco Felsch wrote:
> Add device-tree binding documentation for the tps380x reset driver. The
> binding uses enum to make it easy to add more devices from that family.
> 
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof

Re: [PATCH 2/2] reset: tps380x: Add TPS380x device driver supprt

[Krzysztof Kozlowski]

On 25/05/2022 16:20, Marco Felsch wrote:
> The TI TPS380x family [1] is a volatage supervisor with a dedicated
> manual reset (mr) line input and a reset output. The chip(s) have a
> build in reset delay, depending on the chip partnumber. This simple
> driver addresses this so the cosumer don't need to care about it.
> 
> [1] https://www.ti.com/product/TPS3801
> 
> Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> ---
>  drivers/reset/Kconfig         |   8 +++
>  drivers/reset/Makefile        |   1 +
>  drivers/reset/reset-tps380x.c | 130 ++++++++++++++++++++++++++++++++++
>  3 files changed, 139 insertions(+)
>  create mode 100644 drivers/reset/reset-tps380x.c
> 
> diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> index e0fc80e041ea..e2eb616af812 100644
> --- a/drivers/reset/Kconfig
> +++ b/drivers/reset/Kconfig
> @@ -256,6 +256,14 @@ config RESET_TI_SYSCON
>  	  you wish to use the reset framework for such memory-mapped devices,
>  	  say Y here. Otherwise, say N.
>  
> +config RESET_TI_TPS380X
> +	tristate "TI TPS380x Reset Driver"
> +	select GPIOLIB
> +	help
> +	  This enables the reset driver support for TI TPS380x devices. If
> +	  you wish to use the reset framework for such devices, say Y here.
> +	  Otherwise, say N.
> +
>  config RESET_TN48M_CPLD
>  	tristate "Delta Networks TN48M switch CPLD reset controller"
>  	depends on MFD_TN48M_CPLD || COMPILE_TEST
> diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
> index a80a9c4008a7..66399b92b1bb 100644
> --- a/drivers/reset/Makefile
> +++ b/drivers/reset/Makefile
> @@ -33,6 +33,7 @@ obj-$(CONFIG_RESET_STARFIVE_JH7100) += reset-starfive-jh7100.o
>  obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
>  obj-$(CONFIG_RESET_TI_SCI) += reset-ti-sci.o
>  obj-$(CONFIG_RESET_TI_SYSCON) += reset-ti-syscon.o
> +obj-$(CONFIG_RESET_TI_TPS380X) += reset-tps380x.o
>  obj-$(CONFIG_RESET_TN48M_CPLD) += reset-tn48m.o
>  obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
>  obj-$(CONFIG_RESET_UNIPHIER_GLUE) += reset-uniphier-glue.o
> diff --git a/drivers/reset/reset-tps380x.c b/drivers/reset/reset-tps380x.c
> new file mode 100644
> index 000000000000..fd2c0929ae2d
> --- /dev/null
> +++ b/drivers/reset/reset-tps380x.c
> @@ -0,0 +1,130 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * TI TPS380x Supply Voltage Supervisor and Reset Controller Driver
> + *
> + * Copyright (C) 2022 Pengutronix, Marco Felsch <kernel@pengutronix.de>
> + *
> + * Based on Simple Reset Controller Driver
> + *
> + * Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de>
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/property.h>
> +#include <linux/reset-controller.h>
> +
> +struct tps380x_reset {
> +	struct reset_controller_dev	rcdev;
> +	struct gpio_desc		*reset_gpio;
> +	unsigned int			reset_ms;
> +};
> +
> +struct tps380x_reset_devdata {
> +	unsigned int min_reset_ms;
> +	unsigned int typ_reset_ms;
> +	unsigned int max_reset_ms;
> +};
> +
> +static inline
> +struct tps380x_reset *to_tps380x_reset(struct reset_controller_dev *rcdev)
> +{
> +	return container_of(rcdev, struct tps380x_reset, rcdev);
> +}
> +
> +static int
> +tps380x_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
> +{
> +	struct tps380x_reset *tps380x = to_tps380x_reset(rcdev);
> +
> +	gpiod_set_value_cansleep(tps380x->reset_gpio, 1);
> +
> +	return 0;
> +}
> +
> +static int
> +tps380x_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
> +{
> +	struct tps380x_reset *tps380x = to_tps380x_reset(rcdev);
> +
> +	gpiod_set_value_cansleep(tps380x->reset_gpio, 0);
> +	msleep(tps380x->reset_ms);
> +
> +	return 0;
> +}
> +
> +const struct reset_control_ops reset_tps380x_ops = {

This looks static.


Best regards,
Krzysztof

Re: [PATCH 2/2] reset: tps380x: Add TPS380x device driver supprt

[Marco Felsch]

On 22-05-26, Krzysztof Kozlowski wrote:
> On 25/05/2022 16:20, Marco Felsch wrote:
> > The TI TPS380x family [1] is a volatage supervisor with a dedicated
> > manual reset (mr) line input and a reset output. The chip(s) have a
> > build in reset delay, depending on the chip partnumber. This simple
> > driver addresses this so the cosumer don't need to care about it.
> > 
> > [1] https://www.ti.com/product/TPS3801
> > 
> > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > ---
> >  drivers/reset/Kconfig         |   8 +++
> >  drivers/reset/Makefile        |   1 +
> >  drivers/reset/reset-tps380x.c | 130 ++++++++++++++++++++++++++++++++++
> >  3 files changed, 139 insertions(+)
> >  create mode 100644 drivers/reset/reset-tps380x.c
> > 
> > diff --git a/drivers/reset/Kconfig b/drivers/reset/Kconfig
> > index e0fc80e041ea..e2eb616af812 100644
> > --- a/drivers/reset/Kconfig
> > +++ b/drivers/reset/Kconfig
> > @@ -256,6 +256,14 @@ config RESET_TI_SYSCON
> >  	  you wish to use the reset framework for such memory-mapped devices,
> >  	  say Y here. Otherwise, say N.
> >  
> > +config RESET_TI_TPS380X
> > +	tristate "TI TPS380x Reset Driver"
> > +	select GPIOLIB
> > +	help
> > +	  This enables the reset driver support for TI TPS380x devices. If
> > +	  you wish to use the reset framework for such devices, say Y here.
> > +	  Otherwise, say N.
> > +
> >  config RESET_TN48M_CPLD
> >  	tristate "Delta Networks TN48M switch CPLD reset controller"
> >  	depends on MFD_TN48M_CPLD || COMPILE_TEST
> > diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile
> > index a80a9c4008a7..66399b92b1bb 100644
> > --- a/drivers/reset/Makefile
> > +++ b/drivers/reset/Makefile
> > @@ -33,6 +33,7 @@ obj-$(CONFIG_RESET_STARFIVE_JH7100) += reset-starfive-jh7100.o
> >  obj-$(CONFIG_RESET_SUNXI) += reset-sunxi.o
> >  obj-$(CONFIG_RESET_TI_SCI) += reset-ti-sci.o
> >  obj-$(CONFIG_RESET_TI_SYSCON) += reset-ti-syscon.o
> > +obj-$(CONFIG_RESET_TI_TPS380X) += reset-tps380x.o
> >  obj-$(CONFIG_RESET_TN48M_CPLD) += reset-tn48m.o
> >  obj-$(CONFIG_RESET_UNIPHIER) += reset-uniphier.o
> >  obj-$(CONFIG_RESET_UNIPHIER_GLUE) += reset-uniphier-glue.o
> > diff --git a/drivers/reset/reset-tps380x.c b/drivers/reset/reset-tps380x.c
> > new file mode 100644
> > index 000000000000..fd2c0929ae2d
> > --- /dev/null
> > +++ b/drivers/reset/reset-tps380x.c
> > @@ -0,0 +1,130 @@
> > +// SPDX-License-Identifier: GPL-2.0-or-later
> > +/*
> > + * TI TPS380x Supply Voltage Supervisor and Reset Controller Driver
> > + *
> > + * Copyright (C) 2022 Pengutronix, Marco Felsch <kernel@pengutronix.de>
> > + *
> > + * Based on Simple Reset Controller Driver
> > + *
> > + * Copyright (C) 2017 Pengutronix, Philipp Zabel <kernel@pengutronix.de>
> > + */
> > +
> > +#include <linux/delay.h>
> > +#include <linux/gpio/consumer.h>
> > +#include <linux/module.h>
> > +#include <linux/of.h>
> > +#include <linux/platform_device.h>
> > +#include <linux/property.h>
> > +#include <linux/reset-controller.h>
> > +
> > +struct tps380x_reset {
> > +	struct reset_controller_dev	rcdev;
> > +	struct gpio_desc		*reset_gpio;
> > +	unsigned int			reset_ms;
> > +};
> > +
> > +struct tps380x_reset_devdata {
> > +	unsigned int min_reset_ms;
> > +	unsigned int typ_reset_ms;
> > +	unsigned int max_reset_ms;
> > +};
> > +
> > +static inline
> > +struct tps380x_reset *to_tps380x_reset(struct reset_controller_dev *rcdev)
> > +{
> > +	return container_of(rcdev, struct tps380x_reset, rcdev);
> > +}
> > +
> > +static int
> > +tps380x_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
> > +{
> > +	struct tps380x_reset *tps380x = to_tps380x_reset(rcdev);
> > +
> > +	gpiod_set_value_cansleep(tps380x->reset_gpio, 1);
> > +
> > +	return 0;
> > +}
> > +
> > +static int
> > +tps380x_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
> > +{
> > +	struct tps380x_reset *tps380x = to_tps380x_reset(rcdev);
> > +
> > +	gpiod_set_value_cansleep(tps380x->reset_gpio, 0);
> > +	msleep(tps380x->reset_ms);
> > +
> > +	return 0;
> > +}
> > +
> > +const struct reset_control_ops reset_tps380x_ops = {
> 
> This looks static.

Hi Krzysztof,

Arg.. of course. I will change that. Thanks for the review.

Regards,
  Marco