diff mbox

[PATCH/RFC,3/6] staging: board: Add support for translating hwirq to virq numbers

Message ID 1428064923-24950-4-git-send-email-geert+renesas@glider.be (mailing list archive)
State RFC
Delegated to: Geert Uytterhoeven
Headers show

Commit Message

Geert Uytterhoeven April 3, 2015, 12:42 p.m. UTC
As of commit 9a1091ef0017c40a ("irqchip: gic: Support hierarchy irq
domain."), GIC IRQ numbers are virtual, breaking hardcoded hardware IRQ
numbers in platform device resources.

Add support for translating hardware IRQ numbers to virtual IRQ numbers,
and fixing up platform device resources with hardcoded IRQ numbers.

Add a copyright header, including the original author.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
---
 drivers/staging/board/board.c | 66 +++++++++++++++++++++++++++++++++++++++++++
 drivers/staging/board/board.h |  5 ++++
 2 files changed, 71 insertions(+)

Comments

Marc Zyngier April 6, 2015, 10:45 a.m. UTC | #1
On 2015-04-03 13:42, Geert Uytterhoeven wrote:
> As of commit 9a1091ef0017c40a ("irqchip: gic: Support hierarchy irq
> domain."), GIC IRQ numbers are virtual, breaking hardcoded hardware 
> IRQ
> numbers in platform device resources.
>
> Add support for translating hardware IRQ numbers to virtual IRQ 
> numbers,
> and fixing up platform device resources with hardcoded IRQ numbers.
>
> Add a copyright header, including the original author.
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
>  drivers/staging/board/board.c | 66
> +++++++++++++++++++++++++++++++++++++++++++
>  drivers/staging/board/board.h |  5 ++++
>  2 files changed, 71 insertions(+)
>
> diff --git a/drivers/staging/board/board.c 
> b/drivers/staging/board/board.c
> index d5a6abc845191c93..b84ac2837a20bf06 100644
> --- a/drivers/staging/board/board.c
> +++ b/drivers/staging/board/board.c
> @@ -1,10 +1,27 @@
> +/*
> + * Copyright (C) 2014 Magnus Damm
> + * Copyright (C) 2015 Glider bvba
> + *
> + * This file is subject to the terms and conditions of the GNU
> General Public
> + * License.  See the file "COPYING" in the main directory of this 
> archive
> + * for more details.
> + */
> +
> +#define pr_fmt(fmt)	"board_staging: "  fmt
> +
>  #include <linux/init.h>
> +#include <linux/irq.h>
>  #include <linux/device.h>
>  #include <linux/kernel.h>
>  #include <linux/of.h>
>  #include <linux/of_address.h>
> +#include <linux/of_irq.h>
> +
>  #include "board.h"
>
> +static struct device_node *irqc_node __initdata;
> +static unsigned int irqc_base __initdata;
> +
>  static bool find_by_address(u64 base_address)
>  {
>  	struct device_node *dn = of_find_all_nodes(NULL);
> @@ -38,3 +55,52 @@ bool __init board_staging_dt_node_available(const
> struct resource *resource,
>
>  	return false; /* Nothing found */
>  }
> +
> +int __init board_staging_setup_hwirq_xlate(const char *irqc_match,
> +					   unsigned int base)
> +{
> +	irqc_node = of_find_compatible_node(NULL, NULL, irqc_match);
> +
> +	WARN_ON(!irqc_node);
> +	if (!irqc_node)
> +		return -ENOENT;
> +
> +	irqc_base = base;
> +	return 0;
> +}

And what happens when you have multiple (cascaded) interrupt 
controllers, each wanting to register with this translation service? You 
should at least check that nobody has been here before.

> +static unsigned int __init xlate_hwirq(unsigned int hwirq)
> +{
> +	struct of_phandle_args irq_data;
> +	unsigned int irq;
> +
> +	if (!irqc_node)
> +		return hwirq;
> +
> +	irq_data.np = irqc_node;
> +	irq_data.args_count = 3;
> +	irq_data.args[0] = 0;
> +	irq_data.args[1] = hwirq - irqc_base;
> +	irq_data.args[2] = IRQ_TYPE_LEVEL_HIGH;

And what happens for edge interrupts? Or LEVEL_LOW? This is very much 
GIC specific (3 args...). How does it work with non-GIC interrupt 
controllers?

> +
> +	irq = irq_create_of_mapping(&irq_data);
> +	if (WARN_ON(!irq))
> +		irq = hwirq;
> +
> +	return irq;
> +}
> +
> +void __init board_staging_fixup_irq_resources(struct resource *res,
> +					      unsigned int nres)
> +{
> +	unsigned int i;
> +
> +	for (i = 0; i < nres; i++)
> +		if (res[i].flags == IORESOURCE_IRQ) {
> +			unsigned int hwirq = res[i].start;
> +			unsigned int virq = xlate_hwirq(hwirq);
> +
> +			pr_debug("hwirq %u -> virq %u\n", hwirq, virq);
> +			res[i].start = virq;
> +		}
> +}
> diff --git a/drivers/staging/board/board.h 
> b/drivers/staging/board/board.h
> index e9c914985d4acb36..4cedc3c46e287eb7 100644
> --- a/drivers/staging/board/board.h
> +++ b/drivers/staging/board/board.h
> @@ -1,10 +1,15 @@
>  #ifndef __BOARD_H__
>  #define __BOARD_H__
> +
>  #include <linux/init.h>
>  #include <linux/of.h>
>
> +struct resource;
> +
>  bool board_staging_dt_node_available(const struct resource 
> *resource,
>  				     unsigned int num_resources);
> +int board_staging_setup_hwirq_xlate(const char *irqc_match, unsigned
> int base);
> +void board_staging_fixup_irq_resources(struct resource *res,
> unsigned int nres);
>
>  #define board_staging(str, fn)			\
>  static int __init runtime_board_check(void)	\

It won't surprise you that I don't really like this approach. It is 
controller-specific, restrictive, and allows platform code to continue 
doing something that is essentially wrong. Should this code ever move 
out of staging, it should depend on CONFIG_BROKEN, because this is 
essentially what it is - support code for broken systems. I'd also 
welcome moving parts of the OMAP4/5 code to such CONFIG_BROKEN 
dependency.

Thanks,

         M.
diff mbox

Patch

diff --git a/drivers/staging/board/board.c b/drivers/staging/board/board.c
index d5a6abc845191c93..b84ac2837a20bf06 100644
--- a/drivers/staging/board/board.c
+++ b/drivers/staging/board/board.c
@@ -1,10 +1,27 @@ 
+/*
+ * Copyright (C) 2014 Magnus Damm
+ * Copyright (C) 2015 Glider bvba
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+
+#define pr_fmt(fmt)	"board_staging: "  fmt
+
 #include <linux/init.h>
+#include <linux/irq.h>
 #include <linux/device.h>
 #include <linux/kernel.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
+#include <linux/of_irq.h>
+
 #include "board.h"
 
+static struct device_node *irqc_node __initdata;
+static unsigned int irqc_base __initdata;
+
 static bool find_by_address(u64 base_address)
 {
 	struct device_node *dn = of_find_all_nodes(NULL);
@@ -38,3 +55,52 @@  bool __init board_staging_dt_node_available(const struct resource *resource,
 
 	return false; /* Nothing found */
 }
+
+int __init board_staging_setup_hwirq_xlate(const char *irqc_match,
+					   unsigned int base)
+{
+	irqc_node = of_find_compatible_node(NULL, NULL, irqc_match);
+
+	WARN_ON(!irqc_node);
+	if (!irqc_node)
+		return -ENOENT;
+
+	irqc_base = base;
+	return 0;
+}
+
+static unsigned int __init xlate_hwirq(unsigned int hwirq)
+{
+	struct of_phandle_args irq_data;
+	unsigned int irq;
+
+	if (!irqc_node)
+		return hwirq;
+
+	irq_data.np = irqc_node;
+	irq_data.args_count = 3;
+	irq_data.args[0] = 0;
+	irq_data.args[1] = hwirq - irqc_base;
+	irq_data.args[2] = IRQ_TYPE_LEVEL_HIGH;
+
+	irq = irq_create_of_mapping(&irq_data);
+	if (WARN_ON(!irq))
+		irq = hwirq;
+
+	return irq;
+}
+
+void __init board_staging_fixup_irq_resources(struct resource *res,
+					      unsigned int nres)
+{
+	unsigned int i;
+
+	for (i = 0; i < nres; i++)
+		if (res[i].flags == IORESOURCE_IRQ) {
+			unsigned int hwirq = res[i].start;
+			unsigned int virq = xlate_hwirq(hwirq);
+
+			pr_debug("hwirq %u -> virq %u\n", hwirq, virq);
+			res[i].start = virq;
+		}
+}
diff --git a/drivers/staging/board/board.h b/drivers/staging/board/board.h
index e9c914985d4acb36..4cedc3c46e287eb7 100644
--- a/drivers/staging/board/board.h
+++ b/drivers/staging/board/board.h
@@ -1,10 +1,15 @@ 
 #ifndef __BOARD_H__
 #define __BOARD_H__
+
 #include <linux/init.h>
 #include <linux/of.h>
 
+struct resource;
+
 bool board_staging_dt_node_available(const struct resource *resource,
 				     unsigned int num_resources);
+int board_staging_setup_hwirq_xlate(const char *irqc_match, unsigned int base);
+void board_staging_fixup_irq_resources(struct resource *res, unsigned int nres);
 
 #define board_staging(str, fn)			\
 static int __init runtime_board_check(void)	\