[PATCH V2 6/7] ARM: OMAP4+: Correct Wakeup-gen code to use physical irq number

[Sricharan R]

The wakeup gen mask/unmask callback uses the irq element of the
irq_data to setup. The irq is the linux virtual irq number and
is same as the hardware irq number only when the parent irqchip
is setup as a legacy domain. When it is used as a linear domain,
the virtual irqs are allocated dynamically and wakeup gen code
cannot rely on these numbers to access the irq registers. Instead
use the hwirq element of the irq_data which represent the physical
irq number.

Cc: Santosh Shilimkar <santosh....@ti.com>
Cc: Rajendra Nayak <rna...@ti.com>
Cc: Tony Lindgren <to...@atomide.com>
Signed-off-by: Sricharan R <r.sri...@ti.com>
---
arch/arm/mach-omap2/omap-wakeupgen.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/mach-omap2/omap-wakeupgen.c b/arch/arm/mach-omap2/omap-wakeupgen.c
index e3274bb..c9a5b3c 100644
--- a/arch/arm/mach-omap2/omap-wakeupgen.c
+++ b/arch/arm/mach-omap2/omap-wakeupgen.c
@@ -137,7 +137,7 @@ static void wakeupgen_mask(struct irq_data *d)
unsigned long flags;

raw_spin_lock_irqsave(&wakeupgen_lock, flags);
- _wakeupgen_clear(d->irq, irq_target_cpu[d->irq]);
+ _wakeupgen_clear(d->hwirq, irq_target_cpu[d->hwirq]);
raw_spin_unlock_irqrestore(&wakeupgen_lock, flags);
}

@@ -149,7 +149,7 @@ static void wakeupgen_unmask(struct irq_data *d)
unsigned long flags;

raw_spin_lock_irqsave(&wakeupgen_lock, flags);
- _wakeupgen_set(d->irq, irq_target_cpu[d->irq]);
+ _wakeupgen_set(d->hwirq, irq_target_cpu[d->hwirq]);
raw_spin_unlock_irqrestore(&wakeupgen_lock, flags);
}

--
1.7.9.5

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[Sricharan R]

Some socs have a large number of interrupts requests to service
the needs of its many peripherals and subsystems. All of the
interrupt lines from the subsystems are not needed at the same
time, so they have to be muxed to the irq-controller appropriately.
In such places a interrupt controllers are preceded by an CROSSBAR
that provides flexibility in muxing the device requests to the controller
inputs.

This driver takes care a allocating a free irq and then configuring the
crossbar IP as a part of the mpu's irqchip callbacks. crossbar_init should
be called right before the irqchip_init, so that it is setup to handle the
irqchip callbacks.

Cc: Thomas Gleixner <tg...@linutronix.de>
Cc: Linus Walleij <linus....@linaro.org>
Cc: Santosh Shilimkar <santosh....@ti.com>
Cc: Russell King <li...@arm.linux.org.uk>
Cc: Tony Lindgren <to...@atomide.com>
Cc: Rajendra Nayak <rna...@ti.com>
Cc: Marc Zyngier <marc.z...@arm.com>
Cc: Grant Likely <grant....@linaro.org>
Cc: Rob Herring <rob.h...@calxeda.com>

Signed-off-by: Sricharan R <r.sri...@ti.com>
---

[V2] Addressed Thomas Gleixner <tg...@linutronix.de> comments
and renamed the bindings as per Kumar Gala <ga...@codeaurora.org>
comments.

.../devicetree/bindings/arm/omap/crossbar.txt | 27 +++
drivers/irqchip/Kconfig | 8 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-crossbar.c | 206 ++++++++++++++++++++
include/linux/irqchip/irq-crossbar.h | 11 ++
5 files changed, 253 insertions(+)
create mode 100644 Documentation/devicetree/bindings/arm/omap/crossbar.txt
create mode 100644 drivers/irqchip/irq-crossbar.c
create mode 100644 include/linux/irqchip/irq-crossbar.h

diff --git a/Documentation/devicetree/bindings/arm/omap/crossbar.txt b/Documentation/devicetree/bindings/arm/omap/crossbar.txt
new file mode 100644
index 0000000..fb88585
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/omap/crossbar.txt
@@ -0,0 +1,27 @@
+Some socs have a large number of interrupts requests to service
+the needs of its many peripherals and subsystems. All of the
+interrupt lines from the subsystems are not needed at the same
+time, so they have to be muxed to the irq-controller appropriately.
+In such places a interrupt controllers are preceded by an CROSSBAR
+that provides flexibility in muxing the device requests to the controller
+inputs.
+
+Required properties:
+- compatible : Should be "ti,irq-crossbar"
+- reg: Base address and the size of the crossbar registers.
+- ti,max-irqs: Total number of irqs available at the interrupt controller.
+- ti,reg-size: Size of a individual register in bytes. Every individual
+ register is assumed to be of same size. Valid sizes are 1, 2, 4.
+- ti,irqs-reserved: List of the reserved irq lines that are not muxed using
+ crossbar. These interrupt lines are reserved in the soc,
+ so crossbar bar driver should not consider them as free
+ lines.
+
+Examples:
+ crossbar_mpu: @4a020000 {
+ compatible = "ti,irq-crossbar";
+ reg = <0x4a002a48 0x130>;
+ ti,max-irqs = <160>;
+ ti,reg-size = <2>;
+ ti,irqs-reserved = <0 1 2 3 5 6 131 132 139 140>;
+ };
diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index 3792a1a..2efcde6 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -61,3 +61,11 @@ config VERSATILE_FPGA_IRQ_NR
int
default 4
depends on VERSATILE_FPGA_IRQ
+
+config IRQ_CROSSBAR
+ bool
+ help
+ Support for a CROSSBAR ip that preceeds the main interrupt controller.
+ The primary irqchip invokes the crossbar's callback which inturn allocates
+ a free irq and configures the IP. Thus the peripheral interrupts are
+ routed to one of the free irqchip interrupt lines.
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index c60b901..2edead9 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -22,3 +22,4 @@ obj-$(CONFIG_RENESAS_IRQC) += irq-renesas-irqc.o
obj-$(CONFIG_VERSATILE_FPGA_IRQ) += irq-versatile-fpga.o
obj-$(CONFIG_ARCH_VT8500) += irq-vt8500.o
obj-$(CONFIG_TB10X_IRQC) += irq-tb10x.o
+obj-$(CONFIG_IRQ_CROSSBAR) += irq-crossbar.o
diff --git a/drivers/irqchip/irq-crossbar.c b/drivers/irqchip/irq-crossbar.c
new file mode 100644
index 0000000..2d355e4
--- /dev/null
+++ b/drivers/irqchip/irq-crossbar.c
@@ -0,0 +1,206 @@
+/*
+ * drivers/irqchip/irq-crossbar.c
+ *
+ * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
+ * Author: Sricharan R <r.sri...@ti.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
+#include <linux/irqchip/arm-gic.h>
+
+#define IRQ_FREE -1
+#define GIC_IRQ_START 32
+
+/*
+ * @int_max: maximum number of supported interrupts
+ * @irq_map: array of interrupts to crossbar number mapping
+ * @crossbar_base: crossbar base address
+ * @register_offsets: offsets for each irq number
+ */
+struct crossbar_device {
+ uint int_max;
+ uint *irq_map;
+ void __iomem *crossbar_base;
+ int *register_offsets;
+ void (*write) (int, int);
+};
+
+static struct crossbar_device *cb;
+
+static inline void crossbar_writel(int irq_no, int cb_no)
+{
+ writel(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
+}
+
+static inline void crossbar_writew(int irq_no, int cb_no)
+{
+ writew(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
+}
+
+static inline void crossbar_writeb(int irq_no, int cb_no)
+{
+ writeb(cb_no, cb->crossbar_base + cb->register_offsets[irq_no]);
+}
+
+static inline const u32 allocate_free_irq(int cb_no)
+{
+ int i;
+
+ for (i = 0; i < cb->int_max; i++) {
+ if (cb->irq_map[i] == IRQ_FREE) {
+ cb->irq_map[i] = cb_no;
+ return i;
+ }
+ }
+
+ return -ENODEV;
+}
+
+static int crossbar_domain_map(struct irq_domain *d, unsigned int irq,
+ irq_hw_number_t hw)
+{
+ cb->write(hw - GIC_IRQ_START, cb->irq_map[hw - GIC_IRQ_START]);
+ return 0;
+}
+
+static void crossbar_domain_unmap(struct irq_domain *d, unsigned int irq)
+{
+ irq_hw_number_t hw = irq_get_irq_data(irq)->hwirq;
+
+ if (hw > GIC_IRQ_START)
+ cb->irq_map[hw - GIC_IRQ_START] = IRQ_FREE;
+}
+
+static int crossbar_domain_xlate(struct irq_domain *d,
+ struct device_node *controller,
+ const u32 *intspec, unsigned int intsize,
+ unsigned long *out_hwirq,
+ unsigned int *out_type)
+{
+ unsigned long ret = 0;
+
+ ret = allocate_free_irq(intspec[1]);
+
+ if (IS_ERR_VALUE(ret))
+ return ret;
+
+ *out_hwirq = ret + GIC_IRQ_START;
+ return 0;
+}
+
+const struct irq_domain_ops routable_irq_domain_ops = {
+ .map = crossbar_domain_map,
+ .unmap = crossbar_domain_unmap,
+ .xlate = crossbar_domain_xlate
+};
+
+static int __init crossbar_of_init(struct device_node *node)
+{
+ int i, size, max, reserved = 0, entry;
+ const __be32 *irqsr;
+
+ cb = kzalloc(sizeof(struct cb_device *), GFP_KERNEL);
+
+ if (!cb)
+ return -ENOMEM;
+
+ cb->crossbar_base = of_iomap(node, 0);
+ if (!cb->crossbar_base)
+ goto err1;
+
+ of_property_read_u32(node, "ti,max-irqs", &max);
+ cb->irq_map = kzalloc(max * sizeof(int), GFP_KERNEL);
+ if (!cb->irq_map)
+ goto err2;
+
+ cb->int_max = max;
+
+ for (i = 0; i < max; i++)
+ cb->irq_map[i] = IRQ_FREE;
+
+ /* Get and mark reserved irqs */
+ irqsr = of_get_property(node, "ti,irqs-reserved", &size);
+ if (irqsr) {
+ size /= sizeof(__be32);
+
+ for (i = 0; i < size; i++) {
+ entry = be32_to_cpup(irqsr + i);
+ if (entry > max) {
+ pr_err("Invalid reserved entry\n");
+ goto err3;
+ }
+ cb->irq_map[entry] = 0;
+ }
+ }
+
+ cb->register_offsets = kzalloc(max * sizeof(int), GFP_KERNEL);
+ if (!cb->register_offsets)
+ goto err3;
+
+ of_property_read_u32(node, "ti,reg-size", &size);
+
+ switch (size) {
+ case 1:
+ cb->write = crossbar_writeb;
+ break;
+ case 2:
+ cb->write = crossbar_writew;
+ break;
+ case 4:
+ cb->write = crossbar_writel;
+ break;
+ default:
+ pr_err("Invalid reg-size property\n");
+ goto err4;
+ break;
+ }
+
+ /*
+ * Register offsets are not linear because of the
+ * reserved irqs. so find and store the offsets once.
+ */
+ for (i = 0; i < max; i++) {
+ if (!cb->irq_map[i])
+ continue;
+
+ cb->register_offsets[i] = reserved;
+ reserved += size;
+ }
+
+ register_routable_domain_ops(&routable_irq_domain_ops);
+ return 0;
+
+err4:
+ kfree(cb->register_offsets);
+err3:
+ kfree(cb->irq_map);
+err2:
+ iounmap(cb->crossbar_base);
+err1:
+ kfree(cb);
+ return -ENOMEM;
+}
+
+static const struct of_device_id crossbar_match[] __initconst = {
+ { .compatible = "ti,irq-crossbar" },
+ {}
+};
+
+int crossbar_init(void)
+{
+ struct device_node *np;
+ np = of_find_matching_node(NULL, crossbar_match);
+ if (!np)
+ return -ENODEV;
+
+ crossbar_of_init(np);
+ return 0;
+}
diff --git a/include/linux/irqchip/irq-crossbar.h b/include/linux/irqchip/irq-crossbar.h
new file mode 100644
index 0000000..ad2f744
--- /dev/null
+++ b/include/linux/irqchip/irq-crossbar.h
@@ -0,0 +1,11 @@
+/*
+ * drivers/irqchip/irq-crossbar.h
+ *
+ * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+int crossbar_init(void);

[Sricharan R]

Enable the crossbar IP support for DRA7xx soc.

Cc: Santosh Shilimkar <santosh....@ti.com>

Cc: Rajendra Nayak <rna...@ti.com>
Cc: Tony Lindgren <to...@atomide.com>

Signed-off-by: Sricharan R <r.sri...@ti.com>
---

arch/arm/mach-omap2/Kconfig | 2 +-
arch/arm/mach-omap2/omap4-common.c | 4 ++++
2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-omap2/Kconfig b/arch/arm/mach-omap2/Kconfig
index d2d0227..73c4889 100644
--- a/arch/arm/mach-omap2/Kconfig
+++ b/arch/arm/mach-omap2/Kconfig
@@ -123,9 +123,9 @@ config SOC_DRA7XX
select ARM_GIC
select HAVE_SMP
select COMMON_CLK
- select CROSSBAR
select ARCH_HAS_RESET_CONTROLLER
select RESET_TI
+ select IRQ_CROSSBAR

comment "OMAP Core Type"
depends on ARCH_OMAP2
diff --git a/arch/arm/mach-omap2/omap4-common.c b/arch/arm/mach-omap2/omap4-common.c
index 40c265e..f64826f 100644
--- a/arch/arm/mach-omap2/omap4-common.c
+++ b/arch/arm/mach-omap2/omap4-common.c
@@ -22,6 +22,7 @@
#include <linux/of_platform.h>
#include <linux/export.h>
#include <linux/irqchip/arm-gic.h>
+#include <linux/irqchip/irq-crossbar.h>
#include <linux/of_address.h>
#include <linux/reboot.h>

@@ -291,9 +292,12 @@ void __init omap_gic_of_init(void)

skip_errata_init:
omap_wakeupgen_init();
+ if (soc_is_dra7xx())
+ crossbar_init();
irqchip_init();
}

+
#if defined(CONFIG_MMC_OMAP_HS) || defined(CONFIG_MMC_OMAP_HS_MODULE)
static int omap4_twl6030_hsmmc_late_init(struct device *dev)
{

[Thomas Gleixner]

On Wed, 30 Oct 2013, Sricharan R wrote:
> +static inline const u32 allocate_free_irq(int cb_no)

I understand the "static inline" part, but "const u32" is more than
fishy. What's wrong with "static inline int" ?

> +{
> + int i;
> +
> + for (i = 0; i < cb->int_max; i++) {
> + if (cb->irq_map[i] == IRQ_FREE) {
> + cb->irq_map[i] = cb_no;
> + return i;
> + }
> + }
> +
> + return -ENODEV;
> +}

> +static int crossbar_domain_xlate(struct irq_domain *d,
> + struct device_node *controller,
> + const u32 *intspec, unsigned int intsize,
> + unsigned long *out_hwirq,
> + unsigned int *out_type)
> +{
> + unsigned long ret = 0;

Why do you need to initialize ret when you assign a value to it in the
next line?

Thanks,

tglx

[R, Sricharan]

Hi Thomas,
Again sorry for top post.

I agree and will fix both of the comments below.

Thanks for the reviews.

Regards,
Sricharan
________________________________________
From: Thomas Gleixner [tg...@linutronix.de]
Sent: Wednesday, October 30, 2013 9:00 PM
To: R, Sricharan
Cc: linux-...@vger.kernel.org; devic...@vger.kernel.org; linu...@vger.kernel.org; linux-ar...@lists.infradead.org; linux...@vger.kernel.org; linus....@linaro.org; li...@arm.linux.org.uk; to...@atomide.com; Nayak, Rajendra; marc.z...@arm.com; grant....@linaro.org; mark.r...@arm.com; robhe...@gmail.com; Shilimkar, Santosh; Rob Herring
Subject: Re: [PATCH V2 2/7] DRIVERS: IRQCHIP: CROSSBAR: Add support for Crossbar IP