[PATCH v2 0/3] gnss: ubx: updates to support the Renesas KingFisher board

[PATCH v2 0/3] gnss: ubx: updates to support the Renesas KingFisher board

[Wolfram Sang]

For that, we need "reset-gpio" support (patches 2+3). But first,
simplify regulator handling with a new helper (patch 1).

For changes, see the patches.

Wolfram Sang (3):
  gnss: ubx: use new helper to remove open coded regulator handling
  dt-bindings: gnss: u-blox: add "reset-gpios" binding
  gnss: ubx: add support for the reset gpio

 .../bindings/gnss/u-blox,neo-6m.yaml          |  5 +++
 drivers/gnss/ubx.c                            | 35 ++++++++-----------
 2 files changed, 20 insertions(+), 20 deletions(-)

-- 
2.35.1

[PATCH v2 1/3] gnss: ubx: use new helper to remove open coded regulator handling

[Wolfram Sang]

v_bckp shall always be enabled as long as the device exists. We now have
a regulator helper for that, use it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
---

Change since v1:
* added tag (Thanks, Geert!)

 drivers/gnss/ubx.c | 26 ++++----------------------
 1 file changed, 4 insertions(+), 22 deletions(-)

diff --git a/drivers/gnss/ubx.c b/drivers/gnss/ubx.c
index c951be202ca2..9b76b101ba5e 100644
--- a/drivers/gnss/ubx.c
+++ b/drivers/gnss/ubx.c
@@ -17,7 +17,6 @@
 #include "serial.h"
 
 struct ubx_data {
-	struct regulator *v_bckp;
 	struct regulator *vcc;
 };
 
@@ -87,30 +86,16 @@ static int ubx_probe(struct serdev_device *serdev)
 		goto err_free_gserial;
 	}
 
-	data->v_bckp = devm_regulator_get_optional(&serdev->dev, "v-bckp");
-	if (IS_ERR(data->v_bckp)) {
-		ret = PTR_ERR(data->v_bckp);
-		if (ret == -ENODEV)
-			data->v_bckp = NULL;
-		else
-			goto err_free_gserial;
-	}
-
-	if (data->v_bckp) {
-		ret = regulator_enable(data->v_bckp);
-		if (ret)
-			goto err_free_gserial;
-	}
+	ret = devm_regulator_get_enable_optional(&serdev->dev, "v-bckp");
+	if (ret < 0 && ret != -ENODEV)
+		goto err_free_gserial;
 
 	ret = gnss_serial_register(gserial);
 	if (ret)
-		goto err_disable_v_bckp;
+		goto err_free_gserial;
 
 	return 0;
 
-err_disable_v_bckp:
-	if (data->v_bckp)
-		regulator_disable(data->v_bckp);
 err_free_gserial:
 	gnss_serial_free(gserial);
 
@@ -120,11 +105,8 @@ static int ubx_probe(struct serdev_device *serdev)
 static void ubx_remove(struct serdev_device *serdev)
 {
 	struct gnss_serial *gserial = serdev_device_get_drvdata(serdev);
-	struct ubx_data *data = gnss_serial_get_drvdata(gserial);
 
 	gnss_serial_deregister(gserial);
-	if (data->v_bckp)
-		regulator_disable(data->v_bckp);
 	gnss_serial_free(gserial);
 }
 
-- 
2.35.1

[PATCH v2 2/3] dt-bindings: gnss: u-blox: add "reset-gpios" binding

[Wolfram Sang]

Needed to enable this chip on a Renesas KingFisher board. Description
copied over from the Mediatek driver which already supports it.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---

Changes since v1:
* dropped obvious description (Thanks, Geert!)
* added missing include (Thanks, Krzysztof and Rob!)

I build tested the change this time.

 Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml b/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml
index 4835a280b3bf..8e97e475613f 100644
--- a/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml
+++ b/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml
@@ -41,6 +41,9 @@ properties:
     description: >
       Backup voltage regulator
 
+  reset-gpios:
+    maxItems: 1
+
 required:
   - compatible
   - vcc-supply
@@ -49,10 +52,12 @@ unevaluatedProperties: false
 
 examples:
   - |
+    #include <dt-bindings/gpio/gpio.h>
     serial {
         gnss {
             compatible = "u-blox,neo-8";
             v-bckp-supply = <&gnss_v_bckp_reg>;
             vcc-supply = <&gnss_vcc_reg>;
+            reset-gpios = <&gpio 1 GPIO_ACTIVE_LOW>;
         };
     };
-- 
2.35.1

[PATCH v2 3/3] gnss: ubx: add support for the reset gpio

[Wolfram Sang]

Tested with a Renesas KingFisher board. Because my GNSS device is hooked
up via UART and I2C simultaneously, I could verify functionality by
opening/closing the GNSS device using UART and see if the corresponding
I2C device was visible on the bus.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
---

Changes since v1:
* proper reverse order in ubx_set_standby (Thanks, Geert!)
* simplified the comment when initiall asserting the GPIO (Thanks, Geert!)

 drivers/gnss/ubx.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/gnss/ubx.c b/drivers/gnss/ubx.c
index 9b76b101ba5e..e7d151cbc8c3 100644
--- a/drivers/gnss/ubx.c
+++ b/drivers/gnss/ubx.c
@@ -7,6 +7,7 @@
 
 #include <linux/errno.h>
 #include <linux/gnss.h>
+#include <linux/gpio/consumer.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
@@ -18,6 +19,7 @@
 
 struct ubx_data {
 	struct regulator *vcc;
+	struct gpio_desc *reset_gpio;
 };
 
 static int ubx_set_active(struct gnss_serial *gserial)
@@ -29,6 +31,8 @@ static int ubx_set_active(struct gnss_serial *gserial)
 	if (ret)
 		return ret;
 
+	gpiod_set_value_cansleep(data->reset_gpio, 0);
+
 	return 0;
 }
 
@@ -37,6 +41,8 @@ static int ubx_set_standby(struct gnss_serial *gserial)
 	struct ubx_data *data = gnss_serial_get_drvdata(gserial);
 	int ret;
 
+	gpiod_set_value_cansleep(data->reset_gpio, 1);
+
 	ret = regulator_disable(data->vcc);
 	if (ret)
 		return ret;
@@ -90,6 +96,13 @@ static int ubx_probe(struct serdev_device *serdev)
 	if (ret < 0 && ret != -ENODEV)
 		goto err_free_gserial;
 
+	/* Start with reset asserted */
+	data->reset_gpio = devm_gpiod_get_optional(&serdev->dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(data->reset_gpio)) {
+		ret = PTR_ERR(data->reset_gpio);
+		goto err_free_gserial;
+	}
+
 	ret = gnss_serial_register(gserial);
 	if (ret)
 		goto err_free_gserial;
-- 
2.35.1

Re: [PATCH v2 2/3] dt-bindings: gnss: u-blox: add "reset-gpios" binding

[Conor Dooley]

[-- Attachment #1: Type: text/plain, Size: 1557 bytes --]

On Wed, Aug 16, 2023 at 07:31:14PM +0200, Wolfram Sang wrote:
> Needed to enable this chip on a Renesas KingFisher board. Description
> copied over from the Mediatek driver which already supports it.
> 
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

Acked-by: Conor Dooley <conor.dooley@microchip.com>

Thanks,
Conor.

> ---
> 
> Changes since v1:
> * dropped obvious description (Thanks, Geert!)
> * added missing include (Thanks, Krzysztof and Rob!)
> 
> I build tested the change this time.
> 
>  Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml b/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml
> index 4835a280b3bf..8e97e475613f 100644
> --- a/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml
> +++ b/Documentation/devicetree/bindings/gnss/u-blox,neo-6m.yaml
> @@ -41,6 +41,9 @@ properties:
>      description: >
>        Backup voltage regulator
>  
> +  reset-gpios:
> +    maxItems: 1
> +
>  required:
>    - compatible
>    - vcc-supply
> @@ -49,10 +52,12 @@ unevaluatedProperties: false
>  
>  examples:
>    - |
> +    #include <dt-bindings/gpio/gpio.h>
>      serial {
>          gnss {
>              compatible = "u-blox,neo-8";
>              v-bckp-supply = <&gnss_v_bckp_reg>;
>              vcc-supply = <&gnss_vcc_reg>;
> +            reset-gpios = <&gpio 1 GPIO_ACTIVE_LOW>;
>          };
>      };
> -- 
> 2.35.1
> 

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Re: [PATCH v2 2/3] dt-bindings: gnss: u-blox: add "reset-gpios" binding

[Geert Uytterhoeven]

On Wed, 16 Aug 2023, Wolfram Sang wrote:
> Needed to enable this chip on a Renesas KingFisher board. Description
> copied over from the Mediatek driver which already supports it.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
>
> Changes since v1:
> * dropped obvious description (Thanks, Geert!)
> * added missing include (Thanks, Krzysztof and Rob!)

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

 						Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
 							    -- Linus Torvalds

Re: [PATCH v2 3/3] gnss: ubx: add support for the reset gpio

[Geert Uytterhoeven]

On Sat, Aug 19, 2023 at 10:56 PM Wolfram Sang
<wsa+renesas@sang-engineering.com> wrote:
> Tested with a Renesas KingFisher board. Because my GNSS device is hooked
> up via UART and I2C simultaneously, I could verify functionality by
> opening/closing the GNSS device using UART and see if the corresponding
> I2C device was visible on the bus.
>
> Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
> ---
>
> Changes since v1:
> * proper reverse order in ubx_set_standby (Thanks, Geert!)
> * simplified the comment when initiall asserting the GPIO (Thanks, Geert!)

Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds