The system controller (SCU) is the central unit to manage the resources
on i.MX8 platforms. The SCU firmware provides a set of APIs to access
the GPIO PINs on the SCU domain.
This patch series implements the standard GPIO driver over the SCU
firmware APIs, so that the GPIOs on the SCU domain could be accessed
like a local GPIO PINs.
Changes in V3:
- follow the other imx8 SCU binding rule and rename the compatible string
from fsl,imx8-scu-gpio to fsl,imx8qxp-sc-gpio
- rename the doc file from fsl,imx8-scu-gpio.yaml to fsl,imx-sc-gpio.yaml
Changes in V2:
- move the driver into the gpio directory per Krzysztof's feedback
- change the subnode description in file fsl,scu.yaml
- fix the dt_binding_check error
Shenwei Wang (3):
dt-bindings: gpio: Add imx scu gpio driver bindings
dt-bindings: firmware: imx: Add imx-scu gpio node
firmware: imx: add imx-scu GPIO driver
.../devicetree/bindings/firmware/fsl,scu.yaml | 5 +
.../bindings/gpio/fsl,imx-sc-gpio.yaml | 40 +++++
drivers/gpio/Kconfig | 4 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-imx-scu.c | 140 ++++++++++++++++++
5 files changed, 190 insertions(+)
create mode 100644 Documentation/devicetree/bindings/gpio/fsl,imx-sc-gpio.yaml
create mode 100644 drivers/gpio/gpio-imx-scu.c
--
2.25.1
Add binding document for the imx scu gpio driver.
Signed-off-by: Shenwei Wang <[email protected]>
---
.../bindings/gpio/fsl,imx-sc-gpio.yaml | 40 +++++++++++++++++++
1 file changed, 40 insertions(+)
create mode 100644 Documentation/devicetree/bindings/gpio/fsl,imx-sc-gpio.yaml
diff --git a/Documentation/devicetree/bindings/gpio/fsl,imx-sc-gpio.yaml b/Documentation/devicetree/bindings/gpio/fsl,imx-sc-gpio.yaml
new file mode 100644
index 000000000000..66abff316c0c
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/fsl,imx-sc-gpio.yaml
@@ -0,0 +1,40 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/fsl,imx-sc-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: GPIO driver over IMX SCU firmware API
+
+maintainers:
+ - Shenwei Wang <[email protected]>
+
+description: |
+ This module provides the standard interface to control the
+ resource pins in SCU domain on i.MX8 platforms.
+
+properties:
+ compatible:
+ enum:
+ - fsl,imx8qxp-sc-gpio
+ - fsl,imx-scu-gpio
+
+ "#gpio-cells":
+ const: 2
+
+ gpio-controller: true
+
+required:
+ - compatible
+ - "#gpio-cells"
+ - gpio-controller
+
+additionalProperties: false
+
+examples:
+ - |
+ gpio0: gpio {
+ compatible = "fsl,imx8qxp-sc-gpio";
+ gpio-controller;
+ #gpio-cells = <2>;
+ };
--
2.25.1
The SCU firmware on i.MX8 platforms provides a set of APIs to
control the GPIO PINs on the SCU domain. This patch implements the
standard GPIO driver interface to access those PINs on the
SCU domain over the SCU APIs.
Signed-off-by: Shenwei Wang <[email protected]>
---
drivers/gpio/Kconfig | 4 ++
drivers/gpio/Makefile | 1 +
drivers/gpio/gpio-imx-scu.c | 140 ++++++++++++++++++++++++++++++++++++
3 files changed, 145 insertions(+)
create mode 100644 drivers/gpio/gpio-imx-scu.c
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 0499c2facbb0..b01310f6ebcc 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -341,6 +341,10 @@ config GPIO_ICH
If unsure, say N.
+config GPIO_IMX_SCU
+ def_bool y
+ depends on IMX_SCU
+
config GPIO_IOP
tristate "Intel IOP GPIO"
depends on ARCH_IOP32X || COMPILE_TEST
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 3fa4f3f93d85..b39ab87793ec 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -70,6 +70,7 @@ obj-$(CONFIG_HTC_EGPIO) += gpio-htc-egpio.o
obj-$(CONFIG_GPIO_I8255) += gpio-i8255.o
obj-$(CONFIG_GPIO_ICH) += gpio-ich.o
obj-$(CONFIG_GPIO_IDT3243X) += gpio-idt3243x.o
+obj-$(CONFIG_GPIO_IMX_SCU) += gpio-imx-scu.o
obj-$(CONFIG_GPIO_IOP) += gpio-iop.o
obj-$(CONFIG_GPIO_IT87) += gpio-it87.o
obj-$(CONFIG_GPIO_IXP4XX) += gpio-ixp4xx.o
diff --git a/drivers/gpio/gpio-imx-scu.c b/drivers/gpio/gpio-imx-scu.c
new file mode 100644
index 000000000000..8891262d609f
--- /dev/null
+++ b/drivers/gpio/gpio-imx-scu.c
@@ -0,0 +1,140 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2021~2022 NXP
+ *
+ * The driver exports a standard gpiochip interface
+ * to control the PIN resources on SCU domain.
+ */
+
+#include <linux/module.h>
+#include <linux/gpio/driver.h>
+#include <linux/platform_device.h>
+#include <linux/firmware/imx/svc/rm.h>
+#include <dt-bindings/firmware/imx/rsrc.h>
+
+struct scu_gpio_priv {
+ struct gpio_chip chip;
+ struct mutex lock;
+ struct device *dev;
+ struct imx_sc_ipc *handle;
+};
+
+static unsigned int scu_rsrc_arr[] = {
+ IMX_SC_R_BOARD_R0,
+ IMX_SC_R_BOARD_R1,
+ IMX_SC_R_BOARD_R2,
+ IMX_SC_R_BOARD_R3,
+ IMX_SC_R_BOARD_R4,
+ IMX_SC_R_BOARD_R5,
+ IMX_SC_R_BOARD_R6,
+ IMX_SC_R_BOARD_R7,
+};
+
+static int imx_scu_gpio_get(struct gpio_chip *chip, unsigned int offset)
+{
+ struct scu_gpio_priv *priv = gpiochip_get_data(chip);
+ int level;
+ int err;
+
+ if (offset >= chip->ngpio)
+ return -EINVAL;
+
+ mutex_lock(&priv->lock);
+
+ /* to read PIN state via scu api */
+ err = imx_sc_misc_get_control(priv->handle,
+ scu_rsrc_arr[offset], 0, &level);
+ mutex_unlock(&priv->lock);
+
+ if (err) {
+ dev_err(priv->dev, "SCU get failed: %d\n", err);
+ return err;
+ }
+
+ return level;
+}
+
+static void imx_scu_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
+{
+ struct scu_gpio_priv *priv = gpiochip_get_data(chip);
+ int err;
+
+ if (offset >= chip->ngpio)
+ return;
+
+ mutex_lock(&priv->lock);
+
+ /* to set PIN output level via scu api */
+ err = imx_sc_misc_set_control(priv->handle,
+ scu_rsrc_arr[offset], 0, value);
+ mutex_unlock(&priv->lock);
+
+ if (err)
+ dev_err(priv->dev, "SCU set (%d) failed: %d\n",
+ scu_rsrc_arr[offset], err);
+}
+
+static int imx_scu_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
+{
+ if (offset >= chip->ngpio)
+ return -EINVAL;
+
+ return GPIO_LINE_DIRECTION_OUT;
+}
+
+static int imx_scu_gpio_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct scu_gpio_priv *priv;
+ struct gpio_chip *gc;
+ int ret;
+
+ priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ ret = imx_scu_get_handle(&priv->handle);
+ if (ret)
+ return ret;
+
+ priv->dev = dev;
+ mutex_init(&priv->lock);
+
+ gc = &priv->chip;
+ gc->base = -1;
+ gc->parent = dev;
+ gc->ngpio = sizeof(scu_rsrc_arr)/sizeof(unsigned int);
+ gc->label = dev_name(dev);
+ gc->get = imx_scu_gpio_get;
+ gc->set = imx_scu_gpio_set;
+ gc->get_direction = imx_scu_gpio_get_direction;
+
+ platform_set_drvdata(pdev, priv);
+
+ return devm_gpiochip_add_data(dev, gc, priv);
+}
+
+static const struct of_device_id imx_scu_gpio_dt_ids[] = {
+ { .compatible = "fsl,imx8qxp-sc-gpio" },
+ { .compatible = "fsl,imx-sc-gpio" },
+ { /* sentinel */ }
+};
+
+static struct platform_driver imx_scu_gpio_driver = {
+ .driver = {
+ .name = "gpio-imx-scu",
+ .of_match_table = imx_scu_gpio_dt_ids,
+ },
+ .probe = imx_scu_gpio_probe,
+};
+
+static int __init _imx_scu_gpio_init(void)
+{
+ return platform_driver_register(&imx_scu_gpio_driver);
+}
+
+subsys_initcall_sync(_imx_scu_gpio_init);
+
+MODULE_AUTHOR("Shenwei Wang <[email protected]>");
+MODULE_DESCRIPTION("NXP GPIO over IMX SCU API");
+MODULE_LICENSE("GPL");
--
2.25.1
Add the description for imx-scu gpio subnode.
Signed-off-by: Shenwei Wang <[email protected]>
Acked-by: Krzysztof Kozlowski <[email protected]>
---
Documentation/devicetree/bindings/firmware/fsl,scu.yaml | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/Documentation/devicetree/bindings/firmware/fsl,scu.yaml b/Documentation/devicetree/bindings/firmware/fsl,scu.yaml
index b40b0ef56978..afcfc8ea90c4 100644
--- a/Documentation/devicetree/bindings/firmware/fsl,scu.yaml
+++ b/Documentation/devicetree/bindings/firmware/fsl,scu.yaml
@@ -30,6 +30,11 @@ properties:
Clock controller node that provides the clocks controlled by the SCU
$ref: /schemas/clock/fsl,scu-clk.yaml
+ gpio:
+ description:
+ Control the GPIO PINs on SCU domain over the firmware APIs
+ $ref: /schemas/gpio/fsl,imx8-scu-gpio.yaml
+
ocotp:
description:
OCOTP controller node provided by the SCU
--
2.25.1
On 10/08/2022 16:30, Shenwei Wang wrote:
> Add binding document for the imx scu gpio driver.
>
> Signed-off-by: Shenwei Wang <[email protected]>
> ---
> .../bindings/gpio/fsl,imx-sc-gpio.yaml | 40 +++++++++++++++++++
> 1 file changed, 40 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/gpio/fsl,imx-sc-gpio.yaml
>
> diff --git a/Documentation/devicetree/bindings/gpio/fsl,imx-sc-gpio.yaml b/Documentation/devicetree/bindings/gpio/fsl,imx-sc-gpio.yaml
> new file mode 100644
> index 000000000000..66abff316c0c
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/fsl,imx-sc-gpio.yaml
> @@ -0,0 +1,40 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/gpio/fsl,imx-sc-gpio.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: GPIO driver over IMX SCU firmware API
> +
> +maintainers:
> + - Shenwei Wang <[email protected]>
> +
> +description: |
> + This module provides the standard interface to control the
> + resource pins in SCU domain on i.MX8 platforms.
> +
> +properties:
> + compatible:
> + enum:
> + - fsl,imx8qxp-sc-gpio
> + - fsl,imx-scu-gpio
This is too generic compatible and it even conflicts with the above...
Your driver binds to both without driver data which is even more
confusing. Make the compatible specific for one, given SoC.
Best regards,
Krzysztof
> -----Original Message-----
> From: Krzysztof Kozlowski <[email protected]>
> Sent: Wednesday, August 10, 2022 9:46 AM
> To: Shenwei Wang <[email protected]>; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; dl-linux-imx <[email protected]>
> Cc: [email protected]; [email protected]; linux-
> [email protected]; [email protected]; [email protected]
> Subject: [EXT] Re: [PATCH v3 1/3] dt-bindings: gpio: Add imx scu gpio driver
> bindings
>
> Caution: EXT Email
>
> On 10/08/2022 16:30, Shenwei Wang wrote:
> > Add binding document for the imx scu gpio driver.
> >
> > Signed-off-by: Shenwei Wang <[email protected]>
> > ---
> > .../bindings/gpio/fsl,imx-sc-gpio.yaml | 40 +++++++++++++++++++
> > +properties:
> > + compatible:
> > + enum:
> > + - fsl,imx8qxp-sc-gpio
> > + - fsl,imx-scu-gpio
>
>
> This is too generic compatible and it even conflicts with the above...
> Your driver binds to both without driver data which is even more confusing.
> Make the compatible specific for one, given SoC.
>
Oh, that's my bad. It is a typo. The generic compatible should be "fsl,imx-sc-gpio".
So far there is no driver data required for both imx8qxp and imx8dxl, but it might be
required sometimes later in case the scu firmware is customized for a specified use case.
That's why I put the generic one here.
Thanks,
Shenwei
>
> Best regards,
> Krzysztof