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* [PATCH] ARM/gpio/dt-bindings: Clean out gpio alias from CLPS711X
@ 2021-03-09 14:20 Linus Walleij
  2021-03-10 18:11 ` Rob Herring
  0 siblings, 1 reply; 2+ messages in thread
From: Linus Walleij @ 2021-03-09 14:20 UTC (permalink / raw)
  To: Alexander Shiyan, linux-arm-kernel
  Cc: Linus Walleij, devicetree, linux-gpio, Rob Herring

This removes the use of GPIO alias from the CLPS711X GPIO
driver.

This driver only use it to add quirks to two GPIO blocks
for which we can reuse the standard property "ngpios" and
define a new Cirrus quirk to do it properly and get rid
of the alias.

The patch changes the driver, the one DTS file and the
bindings in one go: my apologies but this is a lockstep
solution to avoid any unclarities or inbetween states.

Old device trees with aliases are supported but will
produce a warning in dmesg and new properties will take
precedence.

Cc: devicetree@vger.kernel.org
Cc: linux-gpio@vger.kernel.org
Cc: Rob Herring <robh+dt@kernel.org>
Link: https://lore.kernel.org/linux-gpio/CACRpkda8+Lvz+c=ohXsEDkNSQ63hPo613P4p_90fvKyC_kQ_GA@mail.gmail.com/T/#t
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
---
This is a result of a discussion with Rob about whether
we can get rid of GPIO aliases. I think we can at least
get rid of this one.
---
 .../bindings/gpio/gpio-clps711x.txt           | 10 +++---
 arch/arm/boot/dts/ep7209.dtsi                 |  8 ++---
 drivers/gpio/gpio-clps711x.c                  | 36 +++++++++----------
 3 files changed, 26 insertions(+), 28 deletions(-)

diff --git a/Documentation/devicetree/bindings/gpio/gpio-clps711x.txt b/Documentation/devicetree/bindings/gpio/gpio-clps711x.txt
index 0a304ad29d81..c1ff20107607 100644
--- a/Documentation/devicetree/bindings/gpio/gpio-clps711x.txt
+++ b/Documentation/devicetree/bindings/gpio/gpio-clps711x.txt
@@ -11,15 +11,13 @@ Required properties:
     0 = active high
     1 = active low
 
-Note: Each GPIO port should have an alias correctly numbered in "aliases"
-node.
+Optional properties:
+- cirrus,inverted-polarity: The polarity of the GPIO lines is
+  inverted in hardware.
+- ngpios: Number of available GPIO lines 0..n-1, see gpio.txt
 
 Example:
 
-aliases {
-	gpio0 = &porta;
-};
-
 porta: gpio@80000000 {
 	compatible = "cirrus,ep7312-gpio","cirrus,ep7209-gpio";
 	reg = <0x80000000 0x1>, <0x80000040 0x1>;
diff --git a/arch/arm/boot/dts/ep7209.dtsi b/arch/arm/boot/dts/ep7209.dtsi
index 365931f8b48d..7d0f04959fdd 100644
--- a/arch/arm/boot/dts/ep7209.dtsi
+++ b/arch/arm/boot/dts/ep7209.dtsi
@@ -11,10 +11,6 @@ / {
 	compatible = "cirrus,ep7209";
 
 	aliases {
-		gpio0 = &porta;
-		gpio1 = &portb;
-		gpio3 = &portd;
-		gpio4 = &porte;
 		serial0 = &uart1;
 		serial1 = &uart2;
 		spi0 = &spi;
@@ -72,6 +68,8 @@ portd: gpio@80000003 {
 			reg = <0x80000003 0x1 0x80000043 0x1>;
 			gpio-controller;
 			#gpio-cells = <2>;
+			/* This bank have all lines polarity inverted */
+			cirrus,inverted-polarity;
 		};
 
 		porte: gpio@80000083 {
@@ -79,6 +77,8 @@ porte: gpio@80000083 {
 			reg = <0x80000083 0x1 0x800000c3 0x1>;
 			gpio-controller;
 			#gpio-cells = <2>;
+			/* Only 3 GPIOs available on this bank */
+			ngpios = <3>;
 		};
 
 		syscon1: syscon@80000100 {
diff --git a/drivers/gpio/gpio-clps711x.c b/drivers/gpio/gpio-clps711x.c
index 75f6f8d4323e..d2a20dc8f5d9 100644
--- a/drivers/gpio/gpio-clps711x.c
+++ b/drivers/gpio/gpio-clps711x.c
@@ -16,14 +16,11 @@ static int clps711x_gpio_probe(struct platform_device *pdev)
 	void __iomem *dat, *dir;
 	struct gpio_chip *gc;
 	int err, id;
+	u32 ngpios;
 
 	if (!np)
 		return -ENODEV;
 
-	id = of_alias_get_id(np, "gpio");
-	if ((id < 0) || (id > 4))
-		return -ENODEV;
-
 	gc = devm_kzalloc(&pdev->dev, sizeof(*gc), GFP_KERNEL);
 	if (!gc)
 		return -ENOMEM;
@@ -36,29 +33,32 @@ static int clps711x_gpio_probe(struct platform_device *pdev)
 	if (IS_ERR(dir))
 		return PTR_ERR(dir);
 
-	switch (id) {
-	case 3:
+	/* This ID will be negative if there is no alias node */
+	id = of_alias_get_id(np, "gpio");
+
+	if (id >= 0)
+		dev_info(&pdev->dev,
+			 "DT is using deprecated alias, please remove this and "
+			 "replace with proper node attributes\n");
+
+	if (of_property_read_bool(np, "cirrus,inverted-polarity") ||
+	    id == 3)
 		/* PORTD is inverted logic for direction register */
 		err = bgpio_init(gc, &pdev->dev, 1, dat, NULL, NULL,
 				 NULL, dir, 0);
-		break;
-	default:
+	else
 		err = bgpio_init(gc, &pdev->dev, 1, dat, NULL, NULL,
 				 dir, NULL, 0);
-		break;
-	}
-
 	if (err)
 		return err;
 
-	switch (id) {
-	case 4:
-		/* PORTE is 3 lines only */
+	if (id == 4)
+		/* This is just for compatibility with older device trees */
 		gc->ngpio = 3;
-		break;
-	default:
-		break;
-	}
+
+	if (!of_property_read_u32(np, "ngpios", &ngpios))
+		/* PORTE is 3 lines only */
+		gc->ngpio = ngpios;
 
 	gc->base = -1;
 	gc->owner = THIS_MODULE;
-- 
2.29.2


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2021-03-09 14:20 [PATCH] ARM/gpio/dt-bindings: Clean out gpio alias from CLPS711X Linus Walleij
2021-03-10 18:11 ` Rob Herring

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