[PATCH v2 0/3] i2c/busses: Use platform_get_irq/_optional() variants to fetch IRQ's

Hi All,

This patch series aims to drop using platform_get_resource() for IRQ types
in preparation for removal of static setup of IRQ resource from DT core
code.

Dropping usage of platform_get_resource() was agreed based on
the discussion [0].

[0] https://patchwork.kernel.org/project/linux-renesas-soc/
patch/20211209001056.29774-1-prabhakar.mahadev-lad.rj@bp.renesas.com/

Cheers,
Prabhakar

Lad Prabhakar (3):
  i2c: bcm2835: Use platform_get_irq() to get the interrupt
  i2c: sh_mobile: Use platform_get_irq_optional() to get the interrupt
  i2c: riic: Use platform_get_irq() to get the interrupt

 drivers/i2c/busses/i2c-bcm2835.c   | 11 ++++------
 drivers/i2c/busses/i2c-riic.c      | 10 ++++-----
 drivers/i2c/busses/i2c-sh_mobile.c | 34 +++++++++++++++++++++++-------
 3 files changed, 35 insertions(+), 20 deletions(-)

-- 
2.17.1


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platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
v1->v2
* Dropped IRQ0 check
---
 drivers/i2c/busses/i2c-bcm2835.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/i2c/busses/i2c-bcm2835.c b/drivers/i2c/busses/i2c-bcm2835.c
index 37443edbf754..dfc534065595 100644
--- a/drivers/i2c/busses/i2c-bcm2835.c
+++ b/drivers/i2c/busses/i2c-bcm2835.c

@@ -402,7 +402,7 @@ static const struct i2c_adapter_quirks bcm2835_i2c_quirks = {
 static int bcm2835_i2c_probe(struct platform_device *pdev)
 {
 	struct bcm2835_i2c_dev *i2c_dev;
-	struct resource *mem, *irq;
+	struct resource *mem;
 	int ret;
 	struct i2c_adapter *adap;
 	struct clk *mclk;

@@ -452,12 +452,9 @@ static int bcm2835_i2c_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
-	if (!irq) {
-		dev_err(&pdev->dev, "No IRQ resource\n");
-		return -ENODEV;
-	}
-	i2c_dev->irq = irq->start;
+	i2c_dev->irq = platform_get_irq(pdev, 0);
+	if (i2c_dev->irq < 0)
+		return i2c_dev->irq;
 
 	ret = request_irq(i2c_dev->irq, bcm2835_i2c_isr, IRQF_SHARED,
 			  dev_name(&pdev->dev), i2c_dev);

-- 
2.17.1


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On 12/21/21 9:53 AM, Lad Prabhakar wrote:

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>
-- 
Florian

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On Tue, Dec 21, 2021 at 05:53:20PM +0000, Lad Prabhakar wrote:

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Applied to for-next, thanks!

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq_optional() for DT users only.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
v1->v2
* Dropped IRQ0 check
* Simplified code
---
 drivers/i2c/busses/i2c-sh_mobile.c | 34 +++++++++++++++++++++++-------
 1 file changed, 26 insertions(+), 8 deletions(-)

diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c
index 7b8caf172851..9754849dbb23 100644
--- a/drivers/i2c/busses/i2c-sh_mobile.c
+++ b/drivers/i2c/busses/i2c-sh_mobile.c

@@ -830,20 +830,38 @@ static void sh_mobile_i2c_release_dma(struct sh_mobile_i2c_data *pd)
 
 static int sh_mobile_i2c_hook_irqs(struct platform_device *dev, struct sh_mobile_i2c_data *pd)
 {
-	struct resource *res;
-	resource_size_t n;
+	struct device_node *np = dev_of_node(&dev->dev);
 	int k = 0, ret;
 
-	while ((res = platform_get_resource(dev, IORESOURCE_IRQ, k))) {
-		for (n = res->start; n <= res->end; n++) {
-			ret = devm_request_irq(&dev->dev, n, sh_mobile_i2c_isr,
-					  0, dev_name(&dev->dev), pd);
+	if (np) {
+		int irq;
+
+		while ((irq = platform_get_irq_optional(dev, k)) != -ENXIO) {
+			if (irq < 0)
+				return irq;
+			ret = devm_request_irq(&dev->dev, irq, sh_mobile_i2c_isr,
+					       0, dev_name(&dev->dev), pd);
 			if (ret) {
-				dev_err(&dev->dev, "cannot request IRQ %pa\n", &n);
+				dev_err(&dev->dev, "cannot request IRQ %d\n", irq);
 				return ret;
 			}
+			k++;
+		};
+	} else {
+		struct resource *res;
+		resource_size_t n;
+
+		while ((res = platform_get_resource(dev, IORESOURCE_IRQ, k))) {
+			for (n = res->start; n <= res->end; n++) {
+				ret = devm_request_irq(&dev->dev, n, sh_mobile_i2c_isr,
+						       0, dev_name(&dev->dev), pd);
+				if (ret) {
+					dev_err(&dev->dev, "cannot request IRQ %pa\n", &n);
+					return ret;
+				}
+			}
+			k++;
 		}
-		k++;
 	}
 
 	return k > 0 ? 0 : -ENOENT;

-- 
2.17.1


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On Tue, Dec 21, 2021 at 7:21 PM Lad Prabhakar
[off-list ref] wrote:

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq_optional() for DT users only.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

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

Gr{oetje,eeting}s,

                        Geert

--
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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

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On Tue, Dec 21, 2021 at 05:53:21PM +0000, Lad Prabhakar wrote:

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq_optional() for DT users only.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Tested on a Renesas R-Car Gen3 SoC (M3-W) and IIC port still works and
no false positive printouts in the kernel log:

Reviewed-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com>

On Wed, Dec 22, 2021 at 2:41 PM Lad Prabhakar
[off-list ref] wrote:

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq_optional() for DT users only.

...

+       if (np) {

Same comments as per your other patches, i.e.
Why is this check here?

+               int irq;
+
+               while ((irq = platform_get_irq_optional(dev, k)) != -ENXIO) {

Consider 0 as no IRQ.

+                       if (irq < 0)
+                               return irq;
+                       ret = devm_request_irq(&dev->dev, irq, sh_mobile_i2c_isr,
+                                              0, dev_name(&dev->dev), pd);
                        if (ret) {
-                               dev_err(&dev->dev, "cannot request IRQ %pa\n", &n);
+                               dev_err(&dev->dev, "cannot request IRQ %d\n", irq);
                                return ret;
                        }
+                       k++;
+               };
+       } else {
+               struct resource *res;
+               resource_size_t n;
+
+               while ((res = platform_get_resource(dev, IORESOURCE_IRQ, k))) {
+                       for (n = res->start; n <= res->end; n++) {
+                               ret = devm_request_irq(&dev->dev, n, sh_mobile_i2c_isr,
+                                                      0, dev_name(&dev->dev), pd);
+                               if (ret) {
+                                       dev_err(&dev->dev, "cannot request IRQ %pa\n", &n);
+                                       return ret;
+                               }
+                       }
+                       k++;
                }
-               k++;
        }

-- 
With Best Regards,
Andy Shevchenko

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Hi Andy,

Thank you for the review.

-----Original Message-----
From: Andy Shevchenko <redacted>
Sent: 25 December 2021 17:49
To: Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>; Ray Jui <rjui@broadcom.com>; Scott Branden
[off-list ref]; bcm-kernel-feedback-list [off-list ref]; Nicolas
Saenz Julienne [off-list ref]; Chris Brandt [off-list ref]; Wolfram Sang
[off-list ref]; linux-i2c [off-list ref]; linux-rpi-kernel <linux-
rpi-kernel@lists.infradead.org>; linux-arm Mailing List [off-list ref]; Linux-
Renesas [off-list ref]; Linux Kernel Mailing List [off-list ref];
Prabhakarprabhakar.csengg@gmail.com
Subject: Re: [PATCH v2 2/3] i2c: sh_mobile: Use platform_get_irq_optional() to get the interrupt

On Wed, Dec 22, 2021 at 2:41 PM Lad Prabhakar [off-list ref] wrote:

quoted

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue when
using hierarchical interrupt domains using "interrupts" property in
the node as this bypasses the hierarchical setup and messes up the irq
chaining.

In preparation for removal of static setup of IRQ resource from DT
core code use platform_get_irq_optional() for DT users only.

...

quoted

+       if (np) {

Same comments as per your other patches, i.e.
Why is this check here?

Because the interrupt resource has range of interrupts in one IRQ resource [0]. Let me know if there is any other alternative way to avoid such case.

quoted

+               int irq;
+
+               while ((irq = platform_get_irq_optional(dev, k)) !=
+ -ENXIO) {

Consider 0 as no IRQ.

OK.

[0] https://elixir.bootlin.com/linux/v5.16-rc6/source/arch/sh/kernel/cpu/sh4a/setup-sh7724.c#L454

Cheers,
Prabhakar

quoted

+                       if (irq < 0)
+                               return irq;
+                       ret = devm_request_irq(&dev->dev, irq, sh_mobile_i2c_isr,
+                                              0, dev_name(&dev->dev),
+ pd);
                        if (ret) {
-                               dev_err(&dev->dev, "cannot request IRQ %pa\n", &n);
+                               dev_err(&dev->dev, "cannot request IRQ
+ %d\n", irq);
                                return ret;
                        }
+                       k++;
+               };
+       } else {
+               struct resource *res;
+               resource_size_t n;
+
+               while ((res = platform_get_resource(dev, IORESOURCE_IRQ, k))) {
+                       for (n = res->start; n <= res->end; n++) {
+                               ret = devm_request_irq(&dev->dev, n, sh_mobile_i2c_isr,
+                                                      0, dev_name(&dev->dev), pd);
+                               if (ret) {
+                                       dev_err(&dev->dev, "cannot request IRQ %pa\n", &n);
+                                       return ret;
+                               }
+                       }
+                       k++;
                }
-               k++;
        }

--
With Best Regards,
Andy Shevchenko

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On Sun, Dec 26, 2021 at 1:45 AM Prabhakar Mahadev Lad
[off-list ref] wrote:

quoted

On Wed, Dec 22, 2021 at 2:41 PM Lad Prabhakar [off-list ref] wrote:

...

quoted

quoted

+       if (np) {

Same comments as per your other patches, i.e.
Why is this check here?

Because the interrupt resource has range of interrupts in one IRQ resource [0]. Let me know if there is any other alternative way to avoid such case.

Shouldn't be fixed in platform_get_irq_optional() to return IRQ by
index for all cases?

[0] https://elixir.bootlin.com/linux/v5.16-rc6/source/arch/sh/kernel/cpu/sh4a/setup-sh7724.c#L454

-- 
With Best Regards,
Andy Shevchenko

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On Sun, Dec 26, 2021 at 8:41 AM Andy Shevchenko
[off-list ref] wrote:

On Sun, Dec 26, 2021 at 1:45 AM Prabhakar Mahadev Lad
[off-list ref] wrote:

quoted

quoted

On Wed, Dec 22, 2021 at 2:41 PM Lad Prabhakar [off-list ref] wrote:

...

quoted

quoted

quoted

+       if (np) {

Same comments as per your other patches, i.e.
Why is this check here?

Because the interrupt resource has range of interrupts in one IRQ resource [0]. Let me know if there is any other alternative way to avoid such case.

Shouldn't be fixed in platform_get_irq_optional() to return IRQ by
index for all cases?

Sorry, I don't get you here. Wasn't your earlier comment for np check?

Cheers,
Prabhakar

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On Tue, Dec 21, 2021 at 05:53:21PM +0000, Lad Prabhakar wrote:

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq_optional() for DT users only.

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Applied to for-next, thanks!

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
---
v1->v2
* Dropped IRQ0 check
---
 drivers/i2c/busses/i2c-riic.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/i2c/busses/i2c-riic.c b/drivers/i2c/busses/i2c-riic.c
index 78b84445ee6a..8dfd27dc6149 100644
--- a/drivers/i2c/busses/i2c-riic.c
+++ b/drivers/i2c/busses/i2c-riic.c

@@ -433,12 +433,12 @@ static int riic_i2c_probe(struct platform_device *pdev)
 	}
 
 	for (i = 0; i < ARRAY_SIZE(riic_irqs); i++) {
-		res = platform_get_resource(pdev, IORESOURCE_IRQ, riic_irqs[i].res_num);
-		if (!res)
-			return -ENODEV;
+		ret = platform_get_irq(pdev, riic_irqs[i].res_num);
+		if (ret < 0)
+			return ret;
 
-		ret = devm_request_irq(&pdev->dev, res->start, riic_irqs[i].isr,
-					0, riic_irqs[i].name, riic);
+		ret = devm_request_irq(&pdev->dev, ret, riic_irqs[i].isr,
+				       0, riic_irqs[i].name, riic);
 		if (ret) {
 			dev_err(&pdev->dev, "failed to request irq %s\n", riic_irqs[i].name);
 			return ret;

-- 
2.17.1


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On Tue, Dec 21, 2021 at 05:53:22PM +0000, Lad Prabhakar wrote:

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

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

On Tue, Dec 21, 2021 at 7:25 PM Lad Prabhakar
[off-list ref] wrote:

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

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

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On Tue, Dec 21, 2021 at 05:53:22PM +0000, Lad Prabhakar wrote:

platform_get_resource(pdev, IORESOURCE_IRQ, ..) relies on static
allocation of IRQ resources in DT core code, this causes an issue
when using hierarchical interrupt domains using "interrupts" property
in the node as this bypasses the hierarchical setup and messes up the
irq chaining.

In preparation for removal of static setup of IRQ resource from DT core
code use platform_get_irq().

Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

Applied to for-next, thanks!