[PATCH v5 0/2] Add DS4520 GPIO Expander Support

[PATCH v5 0/2] Add DS4520 GPIO Expander Support

[Okan Sahin]

GPIO expander driver and bindings for DS4520.
The patches are required to be applied in sequence.

Changes in v5:
* Patch 1: "dt-bindings: gpio: ds4520: Add ADI DS4520"
  * No change
* Patch 2: "gpio: ds4520: Add ADI DS4520 GPIO Expander Support"
  * Remove unnecessary new lines.
  * Use probe(..) instead of probe_new(..)

Changes in v4:
* Patch 1: "dt-bindings: gpio: ds4520: Add ADI DS4520"
  * No change
* Patch 2: "gpio: ds4520: Add ADI DS4520 GPIO Expander Support"
  * Add, remove unnecessary new lines.

Changes in v3:
* Patch 1: "dt-bindings: gpio: ds4520: Add ADI DS4520"
  * Add ngpios property.
* Patch 2: "gpio: ds4520: Add ADI DS4520 GPIO Expander Support"
  * Add namespace for MACROS
  * Read ngpios from dt
  * Add missing header file

Changes in v2:
* Patch 1: "dt-bindings: gpio: ds4520: Add ADI DS4520"
  * Drop label for gpio node
  * Use consistent quotes
  * Fix filename matching compatible.
* Patch 2: "gpio: ds4520: Add ADI DS4520 GPIO Expander Support"
  * Use regmap_gpio framework
  * Fix typo in Kconfig
  * Fix commit message

Okan Sahin (2):
  dt-bindings: gpio: ds4520: Add ADI DS4520
  gpio: ds4520: Add ADI DS4520 GPIO Expander Support

 .../bindings/gpio/adi,ds4520-gpio.yaml        | 51 ++++++++++++
 drivers/gpio/Kconfig                          | 11 +++
 drivers/gpio/Makefile                         |  1 +
 drivers/gpio/gpio-ds4520.c                    | 80 +++++++++++++++++++
 4 files changed, 143 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/adi,ds4520-gpio.yaml
 create mode 100644 drivers/gpio/gpio-ds4520.c

-- 
2.30.2

[PATCH v5 1/2] dt-bindings: gpio: ds4520: Add ADI DS4520

[Okan Sahin]

Add ADI DS4520 devicetree document.

Signed-off-by: Okan Sahin <okan.sahin@analog.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
---
 .../bindings/gpio/adi,ds4520-gpio.yaml        | 51 +++++++++++++++++++
 1 file changed, 51 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/adi,ds4520-gpio.yaml

diff --git a/Documentation/devicetree/bindings/gpio/adi,ds4520-gpio.yaml b/Documentation/devicetree/bindings/gpio/adi,ds4520-gpio.yaml
new file mode 100644
index 000000000000..25b3198c4d3e
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/adi,ds4520-gpio.yaml
@@ -0,0 +1,51 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/adi,ds4520-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: DS4520 I2C GPIO expander
+
+maintainers:
+  - Okan Sahin <okan.sahin@analog.com>
+
+properties:
+  compatible:
+    enum:
+      - adi,ds4520-gpio
+
+  reg:
+    maxItems: 1
+
+  gpio-controller: true
+
+  "#gpio-cells":
+    const: 2
+
+  ngpios:
+    minimum: 1
+    maximum: 9
+
+required:
+  - compatible
+  - reg
+  - gpio-controller
+  - "#gpio-cells"
+  - ngpios
+
+additionalProperties: false
+
+examples:
+  - |
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        gpio@50 {
+            compatible = "adi,ds4520-gpio";
+            reg = <0x50>;
+            ngpios = <9>;
+            gpio-controller;
+            #gpio-cells = <2>;
+        };
+    };
-- 
2.30.2

[PATCH v5 2/2] gpio: ds4520: Add ADI DS4520 GPIO Expander Support

[Okan Sahin]

The DS4520 is a 9-bit nonvolatile (NV) I/O expander.
It offers users a digitally programmable alternative
to hardware jumpers and mechanical switches that are
being used to control digital logic node.

Signed-off-by: Okan Sahin <okan.sahin@analog.com>
---
 drivers/gpio/Kconfig       | 11 ++++++
 drivers/gpio/Makefile      |  1 +
 drivers/gpio/gpio-ds4520.c | 80 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 92 insertions(+)
 create mode 100644 drivers/gpio/gpio-ds4520.c

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 13be729710f2..5f89e46d6411 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -1000,6 +1000,17 @@ config GPIO_ADNP
 	  enough to represent all pins, but the driver will assume a
 	  register layout for 64 pins (8 registers).
 
+config GPIO_DS4520
+	tristate "DS4520 I2C GPIO expander"
+	select REGMAP_I2C
+	select GPIO_REGMAP
+	help
+	  GPIO driver for ADI DS4520 I2C-based GPIO expander.
+	  Say yes here to enable the GPIO driver for the ADI DS4520 chip.
+
+	  To compile this driver as a module, choose M here: the module will
+	  be called gpio-ds4520.
+
 config GPIO_GW_PLD
 	tristate "Gateworks PLD GPIO Expander"
 	depends on OF_GPIO
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index c048ba003367..6f8656d5d617 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_GPIO_DA9052)		+= gpio-da9052.o
 obj-$(CONFIG_GPIO_DA9055)		+= gpio-da9055.o
 obj-$(CONFIG_GPIO_DAVINCI)		+= gpio-davinci.o
 obj-$(CONFIG_GPIO_DLN2)			+= gpio-dln2.o
+obj-$(CONFIG_GPIO_DS4520)		+= gpio-ds4520.o
 obj-$(CONFIG_GPIO_DWAPB)		+= gpio-dwapb.o
 obj-$(CONFIG_GPIO_EIC_SPRD)		+= gpio-eic-sprd.o
 obj-$(CONFIG_GPIO_EM)			+= gpio-em.o
diff --git a/drivers/gpio/gpio-ds4520.c b/drivers/gpio/gpio-ds4520.c
new file mode 100644
index 000000000000..1903deaef3e9
--- /dev/null
+++ b/drivers/gpio/gpio-ds4520.c
@@ -0,0 +1,80 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2023 Analog Devices, Inc.
+ * Driver for the DS4520 I/O Expander
+ */
+
+#include <linux/device.h>
+#include <linux/gpio/driver.h>
+#include <linux/gpio/regmap.h>
+#include <linux/i2c.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+
+#define DS4520_PULLUP0		0xF0
+#define DS4520_IO_CONTROL0	0xF2
+#define DS4520_IO_STATUS0	0xF8
+
+static const struct regmap_config ds4520_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+};
+
+static int ds4520_gpio_probe(struct i2c_client *client)
+{
+	struct gpio_regmap_config config = { };
+	struct device *dev = &client->dev;
+	struct regmap *regmap;
+	u32 ngpio;
+	u32 base;
+	int ret;
+
+	ret = device_property_read_u32(dev, "reg", &base);
+	if (ret)
+		return dev_err_probe(dev, ret, "Missing 'reg' property.\n");
+
+	ret = device_property_read_u32(dev, "ngpios", &ngpio);
+	if (ret)
+		return dev_err_probe(dev, ret, "Missing 'ngpios' property.\n");
+
+	regmap = devm_regmap_init_i2c(client, &ds4520_regmap_config);
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap),
+				     "Failed to allocate register map\n");
+
+	config.regmap = regmap;
+	config.parent = dev;
+	config.ngpio = ngpio;
+
+	config.reg_dat_base = base + DS4520_IO_STATUS0;
+	config.reg_set_base = base + DS4520_PULLUP0;
+	config.reg_dir_out_base = base + DS4520_IO_CONTROL0;
+
+	return PTR_ERR_OR_ZERO(devm_gpio_regmap_register(dev, &config));
+}
+
+static const struct of_device_id ds4520_gpio_of_match_table[] = {
+	{ .compatible = "adi,ds4520-gpio" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ds4520_gpio_of_match_table);
+
+static const struct i2c_device_id ds4520_gpio_id_table[] = {
+	{ "ds4520-gpio" },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, ds4520_gpio_id_table);
+
+static struct i2c_driver ds4520_gpio_driver = {
+	.driver = {
+		.name = "ds4520-gpio",
+		.of_match_table = ds4520_gpio_of_match_table,
+	},
+	.probe = ds4520_gpio_probe,
+	.id_table = ds4520_gpio_id_table,
+};
+module_i2c_driver(ds4520_gpio_driver);
+
+MODULE_DESCRIPTION("DS4520 I/O Expander");
+MODULE_AUTHOR("Okan Sahin <okan.sahin@analog.com>");
+MODULE_LICENSE("GPL");
-- 
2.30.2

Re: [PATCH v5 1/2] dt-bindings: gpio: ds4520: Add ADI DS4520

[Bartosz Golaszewski]

On Thu, Jul 27, 2023 at 11:55 AM Okan Sahin <okan.sahin@analog.com> wrote:
>
> Add ADI DS4520 devicetree document.
>
> Signed-off-by: Okan Sahin <okan.sahin@analog.com>
> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> ---
>  .../bindings/gpio/adi,ds4520-gpio.yaml        | 51 +++++++++++++++++++
>  1 file changed, 51 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/gpio/adi,ds4520-gpio.yaml
>
> diff --git a/Documentation/devicetree/bindings/gpio/adi,ds4520-gpio.yaml b/Documentation/devicetree/bindings/gpio/adi,ds4520-gpio.yaml
> new file mode 100644
> index 000000000000..25b3198c4d3e
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/adi,ds4520-gpio.yaml
> @@ -0,0 +1,51 @@
> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/gpio/adi,ds4520-gpio.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: DS4520 I2C GPIO expander
> +
> +maintainers:
> +  - Okan Sahin <okan.sahin@analog.com>
> +
> +properties:
> +  compatible:
> +    enum:
> +      - adi,ds4520-gpio
> +
> +  reg:
> +    maxItems: 1
> +
> +  gpio-controller: true
> +
> +  "#gpio-cells":
> +    const: 2
> +
> +  ngpios:
> +    minimum: 1
> +    maximum: 9
> +
> +required:
> +  - compatible
> +  - reg
> +  - gpio-controller
> +  - "#gpio-cells"
> +  - ngpios
> +
> +additionalProperties: false
> +
> +examples:
> +  - |
> +    i2c {
> +        #address-cells = <1>;
> +        #size-cells = <0>;
> +
> +        gpio@50 {
> +            compatible = "adi,ds4520-gpio";
> +            reg = <0x50>;
> +            ngpios = <9>;
> +            gpio-controller;
> +            #gpio-cells = <2>;
> +        };
> +    };
> --
> 2.30.2
>

Applied this and the driver, thanks!

Bart

Re: [PATCH v5 2/2] gpio: ds4520: Add ADI DS4520 GPIO Expander Support

[Linus Walleij]

On Thu, Jul 27, 2023 at 11:55 AM Okan Sahin <okan.sahin@analog.com> wrote:

> The DS4520 is a 9-bit nonvolatile (NV) I/O expander.
> It offers users a digitally programmable alternative
> to hardware jumpers and mechanical switches that are
> being used to control digital logic node.
>
> Signed-off-by: Okan Sahin <okan.sahin@analog.com>

Too late to add review tags but just pointing out what a beauty
this driver is when using regmap GPIO. Total success!

Yours,
Linus Walleij

Re: [PATCH v5 2/2] gpio: ds4520: Add ADI DS4520 GPIO Expander Support

[Michael Walle]

Hi,

> On Thu, Jul 27, 2023 at 11:55=E2=80=AFAM Okan Sahin <okan.sahin@analog.com>=
>  wrote:
> 
>> The DS4520 is a 9-bit nonvolatile (NV) I/O expander.
>> It offers users a digitally programmable alternative
>> to hardware jumpers and mechanical switches that are
>> being used to control digital logic node.
>>
>> Signed-off-by: Okan Sahin <okan.sahin@analog.com>
> 
> Too late to add review tags but just pointing out what a beauty
> this driver is when using regmap GPIO. Total success!

Mh somehow I'm always missing consumers of regmap GPIO.

Linus, Bartosz, what do you think about the patch below?

diff --git a/MAINTAINERS b/MAINTAINERS
index 20a0f7411efd..907f39825733 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8868,6 +8868,7 @@ R:        Michael Walle <michael@walle.cc>
 S:     Maintained
 F:     drivers/gpio/gpio-regmap.c
 F:     include/linux/gpio/regmap.h
+K:     (devm_)?gpio_regmap_(un)?register
 
 GPIO SUBSYSTEM
 M:     Linus Walleij <linus.walleij@linaro.org>

-michael

Re: [PATCH v5 2/2] gpio: ds4520: Add ADI DS4520 GPIO Expander Support

[Linus Walleij]

On Wed, Aug 9, 2023 at 9:19 AM Michael Walle <mwalle@kernel.org> wrote:
> > On Thu, Jul 27, 2023 at 11:55=E2=80=AFAM Okan Sahin <okan.sahin@analog.com>=
> >  wrote:
> >
> >> The DS4520 is a 9-bit nonvolatile (NV) I/O expander.
> >> It offers users a digitally programmable alternative
> >> to hardware jumpers and mechanical switches that are
> >> being used to control digital logic node.
> >>
> >> Signed-off-by: Okan Sahin <okan.sahin@analog.com>
> >
> > Too late to add review tags but just pointing out what a beauty
> > this driver is when using regmap GPIO. Total success!
>
> Mh somehow I'm always missing consumers of regmap GPIO.
>
> Linus, Bartosz, what do you think about the patch below?
(...)
> +K:     (devm_)?gpio_regmap_(un)?register

I never saw that globbing trick before, but makes perfect sense so:
Acked-by: Linus Walleij <linus.walleij@linaro.org>

Yours,
Linus Walleij

RE: [PATCH v5 1/2] dt-bindings: gpio: ds4520: Add ADI DS4520

[Sahin, Okan]

>On Thu, Jul 27, 2023 at 11:55 AM Okan Sahin <okan.sahin@analog.com> wrote:
>>
>> Add ADI DS4520 devicetree document.
>>
>> Signed-off-by: Okan Sahin <okan.sahin@analog.com>
>> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
>> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
>> ---
>>  .../bindings/gpio/adi,ds4520-gpio.yaml        | 51 +++++++++++++++++++
>>  1 file changed, 51 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/gpio/adi,ds4520-
>gpio.yaml
>>
>> diff --git a/Documentation/devicetree/bindings/gpio/adi,ds4520-gpio.yaml
>b/Documentation/devicetree/bindings/gpio/adi,ds4520-gpio.yaml
>> new file mode 100644
>> index 000000000000..25b3198c4d3e
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/gpio/adi,ds4520-gpio.yaml
>> @@ -0,0 +1,51 @@
>> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
>> +%YAML 1.2
>> +---
>> +$id:

...

>>
>
>Applied this and the driver, thanks!
>
>Bart

Hi Bart,

When will it be released? I could not find your tree that's why I am asking it.

Regards,
Okan Sahin

Re: [PATCH v5 1/2] dt-bindings: gpio: ds4520: Add ADI DS4520

[Bartosz Golaszewski]

On Mon, Aug 21, 2023 at 12:09 PM Sahin, Okan <Okan.Sahin@analog.com> wrote:
>
>
> >On Thu, Jul 27, 2023 at 11:55 AM Okan Sahin <okan.sahin@analog.com> wrote:
> >>
> >> Add ADI DS4520 devicetree document.
> >>
> >> Signed-off-by: Okan Sahin <okan.sahin@analog.com>
> >> Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
> >> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
> >> ---
> >>  .../bindings/gpio/adi,ds4520-gpio.yaml        | 51 +++++++++++++++++++
> >>  1 file changed, 51 insertions(+)
> >>  create mode 100644 Documentation/devicetree/bindings/gpio/adi,ds4520-
> >gpio.yaml
> >>
> >> diff --git a/Documentation/devicetree/bindings/gpio/adi,ds4520-gpio.yaml
> >b/Documentation/devicetree/bindings/gpio/adi,ds4520-gpio.yaml
> >> new file mode 100644
> >> index 000000000000..25b3198c4d3e
> >> --- /dev/null
> >> +++ b/Documentation/devicetree/bindings/gpio/adi,ds4520-gpio.yaml
> >> @@ -0,0 +1,51 @@
> >> +# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
> >> +%YAML 1.2
> >> +---
> >> +$id:
>
> ...
>
> >>
> >
> >Applied this and the driver, thanks!
> >
> >Bart
>
> Hi Bart,
>
> When will it be released? I could not find your tree that's why I am asking it.
>
> Regards,
> Okan Sahin

It will be released in v6.6 in around 3 months (see
Documentation/process). My tree is listed in the MAINTAINERS file.

Bart