[08/17] soc: ti: pruss: Add a PRUSS irqchip driver for PRUSS interrupts
diff mbox series

Message ID 1542886753-17625-9-git-send-email-rogerq@ti.com
State New
Headers show
Series
  • Add support for TI PRU ICSS
Related show

Commit Message

Roger Quadros Nov. 22, 2018, 11:39 a.m. UTC
From: Suman Anna <s-anna@ti.com>

The Programmable Real-Time Unit Subsystem (PRUSS) contains an
interrupt controller (INTC) that can handle various system input
events and post interrupts back to the device-level initiators.
The INTC can support upto 64 input events with individual control
configuration and hardware prioritization. These events are mapped
onto 10 interrupt signals through two levels of many-to-one mapping
support. Different interrupt signals are routed to the individual
PRU cores or to the host CPU.

The PRUSS INTC platform driver manages this PRUSS interrupt
controller and implements an irqchip driver to provide a Linux
standard way for the PRU client users to enable/disable/ack/
re-trigger a PRUSS system event. The system events to interrupt
channels and host interrupts relies on the mapping configuration
provided through a firmware resource table for now. This will be
revisited and enhanced in the future for a better interface. The
mappings will currently be programmed during the boot/shutdown
of the PRU.

The PRUSS INTC module is reference counted during the interrupt
setup phase through the irqchip's irq_request_resources() and
irq_release_resources() ops. This restricts the module from being
removed as long as there are active interrupt users.

The driver currently supports the AM335x SoC.

Signed-off-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Roger Quadros <rogerq@ti.com>
---
 drivers/soc/ti/Makefile     |   2 +-
 drivers/soc/ti/pruss.h      |  29 +++
 drivers/soc/ti/pruss_intc.c | 572 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 602 insertions(+), 1 deletion(-)
 create mode 100644 drivers/soc/ti/pruss_intc.c

Comments

Tony Lindgren Nov. 23, 2018, 4:37 p.m. UTC | #1
* Roger Quadros <rogerq@ti.com> [181122 11:39]:
> The PRUSS INTC module is reference counted during the interrupt
> setup phase through the irqchip's irq_request_resources() and
> irq_release_resources() ops. This restricts the module from being
> removed as long as there are active interrupt users.

So are there any reasons why this could not be just a regular
drivers/irqchip driver nowadays?

Regards,

Tony
Roger Quadros Nov. 26, 2018, 8:09 a.m. UTC | #2
Tony,

On 23/11/18 18:37, Tony Lindgren wrote:
> * Roger Quadros <rogerq@ti.com> [181122 11:39]:
>> The PRUSS INTC module is reference counted during the interrupt
>> setup phase through the irqchip's irq_request_resources() and
>> irq_release_resources() ops. This restricts the module from being
>> removed as long as there are active interrupt users.
> 
> So are there any reasons why this could not be just a regular
> drivers/irqchip driver nowadays?

This is a reqular irqchip driver. Do you mean it should be moved
to drivers/irqchip directory?

cheers,
-roger
Roger Quadros Nov. 26, 2018, 8:09 a.m. UTC | #3
Tony,

On 23/11/18 18:37, Tony Lindgren wrote:
> * Roger Quadros <rogerq@ti.com> [181122 11:39]:
>> The PRUSS INTC module is reference counted during the interrupt
>> setup phase through the irqchip's irq_request_resources() and
>> irq_release_resources() ops. This restricts the module from being
>> removed as long as there are active interrupt users.
> 
> So are there any reasons why this could not be just a regular
> drivers/irqchip driver nowadays?

This is a regular irqchip driver. Do you mean it should be moved
to drivers/irqchip directory?

cheers,
-roger
Tony Lindgren Nov. 26, 2018, 7:33 p.m. UTC | #4
* Roger Quadros <rogerq@ti.com> [181126 08:09]:
> Tony,
> 
> On 23/11/18 18:37, Tony Lindgren wrote:
> > * Roger Quadros <rogerq@ti.com> [181122 11:39]:
> >> The PRUSS INTC module is reference counted during the interrupt
> >> setup phase through the irqchip's irq_request_resources() and
> >> irq_release_resources() ops. This restricts the module from being
> >> removed as long as there are active interrupt users.
> > 
> > So are there any reasons why this could not be just a regular
> > drivers/irqchip driver nowadays?
> 
> This is a reqular irqchip driver. Do you mean it should be moved
> to drivers/irqchip directory?

I think so, is there something preventing doing it?

Also, is this maybe the same INTC that we already have a
driver for in drivers/irqchip/irq-omap-intc.c?

Regards,

Tony
David Lechner Nov. 26, 2018, 9:17 p.m. UTC | #5
On 11/22/18 5:39 AM, Roger Quadros wrote:
> From: Suman Anna <s-anna@ti.com>
> 
> The Programmable Real-Time Unit Subsystem (PRUSS) contains an
> interrupt controller (INTC) that can handle various system input
> events and post interrupts back to the device-level initiators.
> The INTC can support upto 64 input events with individual control
> configuration and hardware prioritization. These events are mapped
> onto 10 interrupt signals through two levels of many-to-one mapping
> support. Different interrupt signals are routed to the individual
> PRU cores or to the host CPU.
> 
> The PRUSS INTC platform driver manages this PRUSS interrupt
> controller and implements an irqchip driver to provide a Linux
> standard way for the PRU client users to enable/disable/ack/
> re-trigger a PRUSS system event. The system events to interrupt
> channels and host interrupts relies on the mapping configuration
> provided through a firmware resource table for now. This will be
> revisited and enhanced in the future for a better interface. The
> mappings will currently be programmed during the boot/shutdown
> of the PRU.

Does this mapping table take up space in the PRU IRAM or DRAM? If
so, that can be a problem on the AM18xx because it has such limited
resources - every byte counts.

Perhaps one way to simplify the mapping is to take out one of the
two levels of mapping. All of the TRMs say that it is highly
recommended to have a 1:1 mapping from channels to host interrupts.
This part of the mapping could just be hard-coded in this driver.
Then the mapping tables would just effectively mapping PRU system
events to host interrupts.

> 
> The PRUSS INTC module is reference counted during the interrupt
> setup phase through the irqchip's irq_request_resources() and
> irq_release_resources() ops. This restricts the module from being
> removed as long as there are active interrupt users.
> 
> The driver currently supports the AM335x SoC.
> 
> Signed-off-by: Suman Anna <s-anna@ti.com>
> Signed-off-by: Andrew F. Davis <afd@ti.com>
> Signed-off-by: Roger Quadros <rogerq@ti.com>
> ---
>   drivers/soc/ti/Makefile     |   2 +-
>   drivers/soc/ti/pruss.h      |  29 +++
>   drivers/soc/ti/pruss_intc.c | 572 ++++++++++++++++++++++++++++++++++++++++++++
>   3 files changed, 602 insertions(+), 1 deletion(-)
>   create mode 100644 drivers/soc/ti/pruss_intc.c
> 

...

> diff --git a/drivers/soc/ti/pruss_intc.c b/drivers/soc/ti/pruss_intc.c
> new file mode 100644
> index 0000000..dde054b
> --- /dev/null
> +++ b/drivers/soc/ti/pruss_intc.c
> @@ -0,0 +1,572 @@

...

> +int pruss_intc_configure(struct pruss *pruss,
> +			 struct pruss_intc_config *intc_config)
> +{
> +	struct device *dev = pruss->dev;
> +	struct pruss_intc *intc = to_pruss_intc(pruss);
> +	int i, idx, ret;
> +	s8 ch, host;
> +	u64 sysevt_mask = 0;
> +	u32 ch_mask = 0;
> +	u32 host_mask = 0;
> +	u32 val;
> +
> +	if (!intc)
> +		return -EINVAL;
> +
> +	mutex_lock(&intc->lock);
> +
> +	/*
> +	 * configure channel map registers - each register holds map info
> +	 * for 4 events, with each event occupying the lower nibble in
> +	 * a register byte address in little-endian fashion
> +	 */
> +	for (i = 0; i < ARRAY_SIZE(intc_config->sysev_to_ch); i++) {
> +		ch = intc_config->sysev_to_ch[i];
> +		if (ch < 0)
> +			continue;
> +
> +		/* check if sysevent already assigned */
> +		if (intc->config_map.sysev_to_ch[i] != -1) {

Perhaps define a macro for -1 so we know what it means?
Roger Quadros Nov. 27, 2018, 3:39 p.m. UTC | #6
On 26/11/18 23:17, David Lechner wrote:
> On 11/22/18 5:39 AM, Roger Quadros wrote:
>> From: Suman Anna <s-anna@ti.com>
>>
>> The Programmable Real-Time Unit Subsystem (PRUSS) contains an
>> interrupt controller (INTC) that can handle various system input
>> events and post interrupts back to the device-level initiators.
>> The INTC can support upto 64 input events with individual control
>> configuration and hardware prioritization. These events are mapped
>> onto 10 interrupt signals through two levels of many-to-one mapping
>> support. Different interrupt signals are routed to the individual
>> PRU cores or to the host CPU.
>>
>> The PRUSS INTC platform driver manages this PRUSS interrupt
>> controller and implements an irqchip driver to provide a Linux
>> standard way for the PRU client users to enable/disable/ack/
>> re-trigger a PRUSS system event. The system events to interrupt
>> channels and host interrupts relies on the mapping configuration
>> provided through a firmware resource table for now. This will be
>> revisited and enhanced in the future for a better interface. The
>> mappings will currently be programmed during the boot/shutdown
>> of the PRU.
> 
> Does this mapping table take up space in the PRU IRAM or DRAM? If
> so, that can be a problem on the AM18xx because it has such limited
> resources - every byte counts.

Currently the entire resource table is being placed in DRAM.
But that is only because the current rpmsg vdev implementation depends on the
rpmsg channel information and vring buffers to be in DRAM.

I think the right way is to split up the 2 things.
i.e. separate out rpmgs channel DRAM allocation from resource table
and don't copy the resource table to DRAM.

This way if there is no rpmsg channel in the resource table we won't eat
any DRAM.

I'm not sure if there are any bottlenecks. I will only know when I work on it.

> 
> Perhaps one way to simplify the mapping is to take out one of the
> two levels of mapping. All of the TRMs say that it is highly
> recommended to have a 1:1 mapping from channels to host interrupts.
> This part of the mapping could just be hard-coded in this driver.
> Then the mapping tables would just effectively mapping PRU system
> events to host interrupts.

We don't have to go this route if INTC map is not loaded in DRAM.

> 
>>
>> The PRUSS INTC module is reference counted during the interrupt
>> setup phase through the irqchip's irq_request_resources() and
>> irq_release_resources() ops. This restricts the module from being
>> removed as long as there are active interrupt users.
>>
>> The driver currently supports the AM335x SoC.
>>
>> Signed-off-by: Suman Anna <s-anna@ti.com>
>> Signed-off-by: Andrew F. Davis <afd@ti.com>
>> Signed-off-by: Roger Quadros <rogerq@ti.com>
>> ---
>>   drivers/soc/ti/Makefile     |   2 +-
>>   drivers/soc/ti/pruss.h      |  29 +++
>>   drivers/soc/ti/pruss_intc.c | 572 ++++++++++++++++++++++++++++++++++++++++++++
>>   3 files changed, 602 insertions(+), 1 deletion(-)
>>   create mode 100644 drivers/soc/ti/pruss_intc.c
>>
> 
> ...
> 
>> diff --git a/drivers/soc/ti/pruss_intc.c b/drivers/soc/ti/pruss_intc.c
>> new file mode 100644
>> index 0000000..dde054b
>> --- /dev/null
>> +++ b/drivers/soc/ti/pruss_intc.c
>> @@ -0,0 +1,572 @@
> 
> ...
> 
>> +int pruss_intc_configure(struct pruss *pruss,
>> +             struct pruss_intc_config *intc_config)
>> +{
>> +    struct device *dev = pruss->dev;
>> +    struct pruss_intc *intc = to_pruss_intc(pruss);
>> +    int i, idx, ret;
>> +    s8 ch, host;
>> +    u64 sysevt_mask = 0;
>> +    u32 ch_mask = 0;
>> +    u32 host_mask = 0;
>> +    u32 val;
>> +
>> +    if (!intc)
>> +        return -EINVAL;
>> +
>> +    mutex_lock(&intc->lock);
>> +
>> +    /*
>> +     * configure channel map registers - each register holds map info
>> +     * for 4 events, with each event occupying the lower nibble in
>> +     * a register byte address in little-endian fashion
>> +     */
>> +    for (i = 0; i < ARRAY_SIZE(intc_config->sysev_to_ch); i++) {
>> +        ch = intc_config->sysev_to_ch[i];
>> +        if (ch < 0)
>> +            continue;
>> +
>> +        /* check if sysevent already assigned */
>> +        if (intc->config_map.sysev_to_ch[i] != -1) {
> 
> Perhaps define a macro for -1 so we know what it means?

sure.

cheers,
-roger
David Lechner Nov. 28, 2018, 3:46 p.m. UTC | #7
On 11/27/18 9:39 AM, Roger Quadros wrote:
> 
> On 26/11/18 23:17, David Lechner wrote:
>> On 11/22/18 5:39 AM, Roger Quadros wrote:
>>> From: Suman Anna <s-anna@ti.com>
>>>
>>> The Programmable Real-Time Unit Subsystem (PRUSS) contains an
>>> interrupt controller (INTC) that can handle various system input
>>> events and post interrupts back to the device-level initiators.
>>> The INTC can support upto 64 input events with individual control
>>> configuration and hardware prioritization. These events are mapped
>>> onto 10 interrupt signals through two levels of many-to-one mapping
>>> support. Different interrupt signals are routed to the individual
>>> PRU cores or to the host CPU.
>>>
>>> The PRUSS INTC platform driver manages this PRUSS interrupt
>>> controller and implements an irqchip driver to provide a Linux
>>> standard way for the PRU client users to enable/disable/ack/
>>> re-trigger a PRUSS system event. The system events to interrupt
>>> channels and host interrupts relies on the mapping configuration
>>> provided through a firmware resource table for now. This will be
>>> revisited and enhanced in the future for a better interface. The
>>> mappings will currently be programmed during the boot/shutdown
>>> of the PRU.
>>
>> Does this mapping table take up space in the PRU IRAM or DRAM? If
>> so, that can be a problem on the AM18xx because it has such limited
>> resources - every byte counts.
> 
> Currently the entire resource table is being placed in DRAM.
> But that is only because the current rpmsg vdev implementation depends on the
> rpmsg channel information and vring buffers to be in DRAM.
> 
> I think the right way is to split up the 2 things.
> i.e. separate out rpmgs channel DRAM allocation from resource table
> and don't copy the resource table to DRAM.
> 
> This way if there is no rpmsg channel in the resource table we won't eat
> any DRAM.
> 
> I'm not sure if there are any bottlenecks. I will only know when I work on it.

Sounds good to me.
Roger Quadros Dec. 12, 2018, 3:48 p.m. UTC | #8
Tony,

On 26/11/18 21:33, Tony Lindgren wrote:
> * Roger Quadros <rogerq@ti.com> [181126 08:09]:
>> Tony,
>>
>> On 23/11/18 18:37, Tony Lindgren wrote:
>>> * Roger Quadros <rogerq@ti.com> [181122 11:39]:
>>>> The PRUSS INTC module is reference counted during the interrupt
>>>> setup phase through the irqchip's irq_request_resources() and
>>>> irq_release_resources() ops. This restricts the module from being
>>>> removed as long as there are active interrupt users.
>>>
>>> So are there any reasons why this could not be just a regular
>>> drivers/irqchip driver nowadays?
>>
>> This is a reqular irqchip driver. Do you mean it should be moved
>> to drivers/irqchip directory?
> 
> I think so, is there something preventing doing it?
> 
No.

> Also, is this maybe the same INTC that we already have a
> driver for in drivers/irqchip/irq-omap-intc.c?

No, it is completely different.

cheers,
-roger
Tony Lindgren Dec. 12, 2018, 5:25 p.m. UTC | #9
* Roger Quadros <rogerq@ti.com> [181212 15:48]:
> On 26/11/18 21:33, Tony Lindgren wrote:
> >>> So are there any reasons why this could not be just a regular
> >>> drivers/irqchip driver nowadays?
> >>
> >> This is a reqular irqchip driver. Do you mean it should be moved
> >> to drivers/irqchip directory?
> > 
> > I think so, is there something preventing doing it?
> > 
> No.

OK great.

> > Also, is this maybe the same INTC that we already have a
> > driver for in drivers/irqchip/irq-omap-intc.c?
> 
> No, it is completely different.

OK thanks for checking that.

Regards,

Tony

Patch
diff mbox series

diff --git a/drivers/soc/ti/Makefile b/drivers/soc/ti/Makefile
index 5a0c89d..71626a0 100644
--- a/drivers/soc/ti/Makefile
+++ b/drivers/soc/ti/Makefile
@@ -8,4 +8,4 @@  obj-$(CONFIG_KEYSTONE_NAVIGATOR_DMA)	+= knav_dma.o
 obj-$(CONFIG_AMX3_PM)			+= pm33xx.o
 obj-$(CONFIG_WKUP_M3_IPC)		+= wkup_m3_ipc.o
 obj-$(CONFIG_TI_SCI_PM_DOMAINS)		+= ti_sci_pm_domains.o
-obj-$(CONFIG_TI_PRUSS)			+= pruss_soc_bus.o pruss.o
+obj-$(CONFIG_TI_PRUSS)			+= pruss_soc_bus.o pruss.o pruss_intc.o
diff --git a/drivers/soc/ti/pruss.h b/drivers/soc/ti/pruss.h
index dbdf475..a5a0667 100644
--- a/drivers/soc/ti/pruss.h
+++ b/drivers/soc/ti/pruss.h
@@ -9,6 +9,18 @@ 
 #ifndef _PRUSS_H_
 #define _PRUSS_H_
 
+/* maximum number of system events */
+#define MAX_PRU_SYS_EVENTS	64
+
+/* maximum number of interrupt channels */
+#define MAX_PRU_CHANNELS	10
+
+/* minimum starting host interrupt number for MPU */
+#define MIN_PRU_HOST_INT	2
+
+/* maximum number of host interrupts */
+#define MAX_PRU_HOST_INT	10
+
 /**
  * enum pruss_mem - PRUSS memory range identifiers
  */
@@ -32,13 +44,30 @@  struct pruss_mem_region {
 };
 
 /**
+ * struct pruss_intc_config - INTC configuration info
+ * @sysev_to_ch: system events to channel mapping information
+ * @ch_to_host: interrupt channel to host interrupt information
+ */
+struct pruss_intc_config {
+	s8 sysev_to_ch[MAX_PRU_SYS_EVENTS];
+	s8 ch_to_host[MAX_PRU_CHANNELS];
+};
+
+/**
  * struct pruss - PRUSS parent structure
  * @dev: pruss device pointer
  * @mem_regions: data for each of the PRUSS memory regions
+ * @host_mask: indicate which HOST IRQs are enabled
  */
 struct pruss {
 	struct device *dev;
 	struct pruss_mem_region mem_regions[PRUSS_MEM_MAX];
+	u32 host_mask;
 };
 
+int pruss_intc_configure(struct pruss *pruss,
+			 struct pruss_intc_config *intc_config);
+int pruss_intc_unconfigure(struct pruss *pruss,
+			   struct pruss_intc_config *intc_config);
+
 #endif	/* _PRUSS_H_ */
diff --git a/drivers/soc/ti/pruss_intc.c b/drivers/soc/ti/pruss_intc.c
new file mode 100644
index 0000000..dde054b
--- /dev/null
+++ b/drivers/soc/ti/pruss_intc.c
@@ -0,0 +1,572 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PRU-ICSS INTC IRQChip driver for various TI SoCs
+ *
+ * Copyright (C) 2016-2018 Texas Instruments Incorporated - http://www.ti.com/
+ *	Andrew F. Davis <afd@ti.com>
+ *	Suman Anna <s-anna@ti.com>
+ */
+
+#include <linux/irq.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+
+#include "pruss.h"
+
+/*
+ * Number of host interrupts reaching the main MPU sub-system. Note that this
+ * is not the same as the total number of host interrupts supported by the PRUSS
+ * INTC instance
+ */
+#define MAX_HOST_NUM_IRQS	8
+
+/* PRU_ICSS_INTC registers */
+#define PRU_INTC_REVID		0x0000
+#define PRU_INTC_CR		0x0004
+#define PRU_INTC_GER		0x0010
+#define PRU_INTC_GNLR		0x001C
+#define PRU_INTC_SISR		0x0020
+#define PRU_INTC_SICR		0x0024
+#define PRU_INTC_EISR		0x0028
+#define PRU_INTC_EICR		0x002C
+#define PRU_INTC_HIEISR		0x0034
+#define PRU_INTC_HIDISR		0x0038
+#define PRU_INTC_GPIR		0x0080
+#define PRU_INTC_SRSR0		0x0200
+#define PRU_INTC_SRSR1		0x0204
+#define PRU_INTC_SECR0		0x0280
+#define PRU_INTC_SECR1		0x0284
+#define PRU_INTC_ESR0		0x0300
+#define PRU_INTC_ESR1		0x0304
+#define PRU_INTC_ECR0		0x0380
+#define PRU_INTC_ECR1		0x0384
+#define PRU_INTC_CMR(x)		(0x0400 + (x) * 4)
+#define PRU_INTC_HMR(x)		(0x0800 + (x) * 4)
+#define PRU_INTC_HIPIR(x)	(0x0900 + (x) * 4)
+#define PRU_INTC_SIPR0		0x0D00
+#define PRU_INTC_SIPR1		0x0D04
+#define PRU_INTC_SITR0		0x0D80
+#define PRU_INTC_SITR1		0x0D84
+#define PRU_INTC_HINLR(x)	(0x1100 + (x) * 4)
+#define PRU_INTC_HIER		0x1500
+
+/* HIPIR register bit-fields */
+#define INTC_HIPIR_NONE_HINT	0x80000000
+
+static const char * const irq_names[] = {
+	"host2", "host3", "host4", "host5", "host6", "host7", "host8", "host9",
+};
+
+/**
+ * struct pruss_intc - PRUSS interrupt controller structure
+ * @pruss: back-reference to parent PRUSS structure
+ * @irqs: kernel irq numbers corresponding to PRUSS host interrupts
+ * @mem: kernel-mapping data for the INTC register space
+ * @irqchip: irq chip for this interrupt controller
+ * @domain: irq domain for this interrupt controller
+ * @config_map: stored INTC configuration mapping data
+ * @lock: mutex to serialize access to INTC
+ */
+struct pruss_intc {
+	struct pruss *pruss;
+	unsigned int irqs[MAX_HOST_NUM_IRQS];
+	struct pruss_mem_region mem;
+	struct irq_chip *irqchip;
+	struct irq_domain *domain;
+	struct pruss_intc_config config_map;
+	struct mutex lock; /* PRUSS INTC lock */
+};
+
+static inline u32 pruss_intc_read_reg(struct pruss_intc *intc, unsigned int reg)
+{
+	return readl_relaxed(intc->mem.va + reg);
+}
+
+static inline void pruss_intc_write_reg(struct pruss_intc *intc,
+					unsigned int reg, u32 val)
+{
+	writel_relaxed(val, intc->mem.va + reg);
+}
+
+static int pruss_intc_check_write(struct pruss_intc *intc, unsigned int reg,
+				  unsigned int sysevent)
+{
+	if (!intc)
+		return -EINVAL;
+
+	if (sysevent >= MAX_PRU_SYS_EVENTS)
+		return -EINVAL;
+
+	pruss_intc_write_reg(intc, reg, sysevent);
+
+	return 0;
+}
+
+static struct pruss_intc *to_pruss_intc(struct pruss *pruss)
+{
+	struct device_node *parent = pruss->dev->of_node;
+	struct device_node *np;
+	struct platform_device *pdev;
+	struct pruss_intc *intc = NULL;
+
+	np = of_get_child_by_name(parent, "intc");
+	if (!np) {
+		dev_err(pruss->dev, "pruss does not have an intc node\n");
+		return NULL;
+	}
+
+	pdev = of_find_device_by_node(np);
+	if (!pdev) {
+		dev_err(pruss->dev, "no associated platform device\n");
+		goto out;
+	}
+
+	intc = platform_get_drvdata(pdev);
+out:
+	of_node_put(np);
+	return intc;
+}
+
+/**
+ * pruss_intc_configure() - configure the PRUSS INTC
+ * @pruss: the pruss instance
+ * @intc_config: PRU core-specific INTC configuration
+ *
+ * Configures the PRUSS INTC with the provided configuration from
+ * a PRU core. Any existing event to channel mappings or channel to
+ * host interrupt mappings are checked to make sure there are no
+ * conflicting configuration between both the PRU cores. The function
+ * is intended to be used only by the PRU remoteproc driver.
+ *
+ * Returns 0 on success, or a suitable error code otherwise
+ */
+int pruss_intc_configure(struct pruss *pruss,
+			 struct pruss_intc_config *intc_config)
+{
+	struct device *dev = pruss->dev;
+	struct pruss_intc *intc = to_pruss_intc(pruss);
+	int i, idx, ret;
+	s8 ch, host;
+	u64 sysevt_mask = 0;
+	u32 ch_mask = 0;
+	u32 host_mask = 0;
+	u32 val;
+
+	if (!intc)
+		return -EINVAL;
+
+	mutex_lock(&intc->lock);
+
+	/*
+	 * configure channel map registers - each register holds map info
+	 * for 4 events, with each event occupying the lower nibble in
+	 * a register byte address in little-endian fashion
+	 */
+	for (i = 0; i < ARRAY_SIZE(intc_config->sysev_to_ch); i++) {
+		ch = intc_config->sysev_to_ch[i];
+		if (ch < 0)
+			continue;
+
+		/* check if sysevent already assigned */
+		if (intc->config_map.sysev_to_ch[i] != -1) {
+			dev_err(dev, "event %d (req. channel %d) already assigned to channel %d\n",
+				i, ch, intc->config_map.sysev_to_ch[i]);
+			ret = -EEXIST;
+			goto unlock;
+		}
+
+		intc->config_map.sysev_to_ch[i] = ch;
+
+		idx = i / 4;
+		val = pruss_intc_read_reg(intc, PRU_INTC_CMR(idx));
+		val |= ch << ((i & 3) * 8);
+		pruss_intc_write_reg(intc, PRU_INTC_CMR(idx), val);
+		sysevt_mask |= BIT_ULL(i);
+		ch_mask |= BIT(ch);
+
+		dev_dbg(dev, "SYSEV%d -> CH%d (CMR%d 0x%08x)\n", i, ch, idx,
+			pruss_intc_read_reg(intc, PRU_INTC_CMR(idx)));
+	}
+
+	/*
+	 * set host map registers - each register holds map info for
+	 * 4 channels, with each channel occupying the lower nibble in
+	 * a register byte address in little-endian fashion
+	 */
+	for (i = 0; i < ARRAY_SIZE(intc_config->ch_to_host); i++) {
+		host = intc_config->ch_to_host[i];
+		if (host < 0)
+			continue;
+
+		/* check if channel already assigned */
+		if (intc->config_map.ch_to_host[i] != -1) {
+			dev_err(dev, "channel %d (req. intr_no %d) already assigned to intr_no %d\n",
+				i, host, intc->config_map.ch_to_host[i]);
+			ret = -EEXIST;
+			goto unlock;
+		}
+
+		/* check if host intr is already in use by other PRU */
+		if (pruss->host_mask & (1U << host)) {
+			dev_err(dev, "%s: host intr %d already in use\n",
+				__func__, host);
+			ret = -EEXIST;
+			goto unlock;
+		}
+
+		intc->config_map.ch_to_host[i] = host;
+
+		idx = i / 4;
+
+		val = pruss_intc_read_reg(intc, PRU_INTC_HMR(idx));
+		val |= host << ((i & 3) * 8);
+		pruss_intc_write_reg(intc, PRU_INTC_HMR(idx), val);
+
+		ch_mask |= BIT(i);
+		host_mask |= BIT(host);
+
+		dev_dbg(dev, "CH%d -> HOST%d (HMR%d 0x%08x)\n", i, host, idx,
+			pruss_intc_read_reg(intc, PRU_INTC_HMR(idx)));
+	}
+
+	dev_info(dev, "configured system_events = 0x%016llx intr_channels = 0x%08x host_intr = 0x%08x\n",
+		 sysevt_mask, ch_mask, host_mask);
+
+	/* enable system events, writing 0 has no-effect */
+	pruss_intc_write_reg(intc, PRU_INTC_ESR0, lower_32_bits(sysevt_mask));
+	pruss_intc_write_reg(intc, PRU_INTC_SECR0, lower_32_bits(sysevt_mask));
+	pruss_intc_write_reg(intc, PRU_INTC_ESR1, upper_32_bits(sysevt_mask));
+	pruss_intc_write_reg(intc, PRU_INTC_SECR1, upper_32_bits(sysevt_mask));
+
+	/* enable host interrupts */
+	for (i = 0; i < MAX_PRU_HOST_INT; i++) {
+		if (host_mask & BIT(i))
+			pruss_intc_write_reg(intc, PRU_INTC_HIEISR, i);
+	}
+
+	/* global interrupt enable */
+	pruss_intc_write_reg(intc, PRU_INTC_GER, 1);
+
+	pruss->host_mask |= host_mask;
+
+	mutex_unlock(&intc->lock);
+	return 0;
+
+unlock:
+	mutex_unlock(&intc->lock);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pruss_intc_configure);
+
+/**
+ * pruss_intc_unconfigure() - unconfigure the PRUSS INTC
+ * @pruss: the pruss instance
+ * @intc_config: PRU core specific INTC configuration
+ *
+ * Undo whatever was done in pruss_intc_configure() for a PRU core.
+ * It should be sufficient to just mark the resources free in the
+ * global map and disable the host interrupts and sysevents.
+ */
+int pruss_intc_unconfigure(struct pruss *pruss,
+			   struct pruss_intc_config *intc_config)
+{
+	struct device *dev = pruss->dev;
+	struct pruss_intc *intc = to_pruss_intc(pruss);
+	int i;
+	s8 ch, host;
+	u64 sysevt_mask = 0;
+	u32 host_mask = 0;
+
+	if (!intc)
+		return -EINVAL;
+
+	mutex_lock(&intc->lock);
+
+	for (i = 0; i < ARRAY_SIZE(intc_config->sysev_to_ch); i++) {
+		ch = intc_config->sysev_to_ch[i];
+		if (ch < 0)
+			continue;
+
+		/* mark sysevent free in global map */
+		intc->config_map.sysev_to_ch[i] = -1;
+		sysevt_mask |= BIT_ULL(i);
+	}
+
+	for (i = 0; i < ARRAY_SIZE(intc_config->ch_to_host); i++) {
+		host = intc_config->ch_to_host[i];
+		if (host < 0)
+			continue;
+
+		/* mark channel free in global map */
+		intc->config_map.ch_to_host[i] = -1;
+		host_mask |= BIT(host);
+	}
+
+	dev_info(dev, "unconfigured system_events = 0x%016llx host_intr = 0x%08x\n",
+		 sysevt_mask, host_mask);
+
+	/* disable system events, writing 0 has no-effect */
+	pruss_intc_write_reg(intc, PRU_INTC_ECR0, lower_32_bits(sysevt_mask));
+	pruss_intc_write_reg(intc, PRU_INTC_ECR1, upper_32_bits(sysevt_mask));
+	/* clear any pending status */
+	pruss_intc_write_reg(intc, PRU_INTC_SECR0, lower_32_bits(sysevt_mask));
+	pruss_intc_write_reg(intc, PRU_INTC_SECR1, upper_32_bits(sysevt_mask));
+
+	/* disable host interrupts */
+	for (i = 0; i < MAX_PRU_HOST_INT; i++) {
+		if (host_mask & BIT(i))
+			pruss_intc_write_reg(intc, PRU_INTC_HIDISR, i);
+	}
+
+	pruss->host_mask &= ~host_mask;
+	mutex_unlock(&intc->lock);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(pruss_intc_unconfigure);
+
+static void pruss_intc_init(struct pruss_intc *intc)
+{
+	int i;
+
+	/* configure polarity to active high for all system interrupts */
+	pruss_intc_write_reg(intc, PRU_INTC_SIPR0, 0xffffffff);
+	pruss_intc_write_reg(intc, PRU_INTC_SIPR1, 0xffffffff);
+
+	/* configure type to pulse interrupt for all system interrupts */
+	pruss_intc_write_reg(intc, PRU_INTC_SITR0, 0);
+	pruss_intc_write_reg(intc, PRU_INTC_SITR1, 0);
+
+	/* clear all 16 interrupt channel map registers */
+	for (i = 0; i < 16; i++)
+		pruss_intc_write_reg(intc, PRU_INTC_CMR(i), 0);
+
+	/* clear all 3 host interrupt map registers */
+	for (i = 0; i < 3; i++)
+		pruss_intc_write_reg(intc, PRU_INTC_HMR(i), 0);
+}
+
+static void pruss_intc_irq_ack(struct irq_data *data)
+{
+	struct pruss_intc *intc = irq_data_get_irq_chip_data(data);
+	unsigned int hwirq = data->hwirq;
+
+	pruss_intc_check_write(intc, PRU_INTC_SICR, hwirq);
+}
+
+static void pruss_intc_irq_mask(struct irq_data *data)
+{
+	struct pruss_intc *intc = irq_data_get_irq_chip_data(data);
+	unsigned int hwirq = data->hwirq;
+
+	pruss_intc_check_write(intc, PRU_INTC_EICR, hwirq);
+}
+
+static void pruss_intc_irq_unmask(struct irq_data *data)
+{
+	struct pruss_intc *intc = irq_data_get_irq_chip_data(data);
+	unsigned int hwirq = data->hwirq;
+
+	pruss_intc_check_write(intc, PRU_INTC_EISR, hwirq);
+}
+
+static int pruss_intc_irq_retrigger(struct irq_data *data)
+{
+	struct pruss_intc *intc = irq_data_get_irq_chip_data(data);
+	unsigned int hwirq = data->hwirq;
+
+	return pruss_intc_check_write(intc, PRU_INTC_SISR, hwirq);
+}
+
+static int pruss_intc_irq_reqres(struct irq_data *data)
+{
+	if (!try_module_get(THIS_MODULE))
+		return -ENODEV;
+
+	return 0;
+}
+
+static void pruss_intc_irq_relres(struct irq_data *data)
+{
+	module_put(THIS_MODULE);
+}
+
+static int pruss_intc_irq_domain_map(struct irq_domain *d, unsigned int virq,
+				     irq_hw_number_t hw)
+{
+	struct pruss_intc *intc = d->host_data;
+
+	irq_set_chip_data(virq, intc);
+	irq_set_chip_and_handler(virq, intc->irqchip, handle_level_irq);
+
+	return 0;
+}
+
+static void pruss_intc_irq_domain_unmap(struct irq_domain *d, unsigned int virq)
+{
+	irq_set_chip_and_handler(virq, NULL, NULL);
+	irq_set_chip_data(virq, NULL);
+}
+
+static const struct irq_domain_ops pruss_intc_irq_domain_ops = {
+	.xlate	= irq_domain_xlate_onecell,
+	.map	= pruss_intc_irq_domain_map,
+	.unmap	= pruss_intc_irq_domain_unmap,
+};
+
+static void pruss_intc_irq_handler(struct irq_desc *desc)
+{
+	unsigned int irq = irq_desc_get_irq(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct pruss_intc *intc = irq_get_handler_data(irq);
+	u32 hipir;
+	unsigned int virq;
+	int i, hwirq;
+
+	chained_irq_enter(chip, desc);
+
+	/* find our host irq number */
+	for (i = 0; i < MAX_HOST_NUM_IRQS; i++)
+		if (intc->irqs[i] == irq)
+			break;
+	if (i == MAX_HOST_NUM_IRQS)
+		goto err;
+
+	i += MIN_PRU_HOST_INT;
+
+	/* get highest priority pending PRUSS system event */
+	hipir = pruss_intc_read_reg(intc, PRU_INTC_HIPIR(i));
+	while (!(hipir & BIT(31))) {
+		hwirq = hipir & GENMASK(9, 0);
+		virq = irq_linear_revmap(intc->domain, hwirq);
+
+		/*
+		 * XXX: manually ACK any system events that do not have a
+		 * handler mapped yet
+		 */
+		if (unlikely(!virq))
+			pruss_intc_check_write(intc, PRU_INTC_SICR, hwirq);
+		else
+			generic_handle_irq(virq);
+
+		/* get next system event */
+		hipir = pruss_intc_read_reg(intc, PRU_INTC_HIPIR(i));
+	}
+err:
+	chained_irq_exit(chip, desc);
+}
+
+static int pruss_intc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct platform_device *ppdev = to_platform_device(dev->parent);
+	struct pruss_intc *intc;
+	struct resource *res;
+	struct irq_chip *irqchip;
+	int i, irq;
+
+	intc = devm_kzalloc(dev, sizeof(*intc), GFP_KERNEL);
+	if (!intc)
+		return -ENOMEM;
+	platform_set_drvdata(pdev, intc);
+
+	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "intc");
+	intc->mem.va = devm_ioremap_resource(dev, res);
+	if (IS_ERR(intc->mem.va)) {
+		dev_err(dev, "failed to parse and map intc memory resource\n");
+		return PTR_ERR(intc->mem.va);
+	}
+	intc->mem.pa = res->start;
+	intc->mem.size = resource_size(res);
+
+	dev_dbg(dev, "intc memory: pa %pa size 0x%zx va %p\n", &intc->mem.pa,
+		intc->mem.size, intc->mem.va);
+
+	mutex_init(&intc->lock);
+
+	for (i = 0; i < ARRAY_SIZE(intc->config_map.sysev_to_ch); i++)
+		intc->config_map.sysev_to_ch[i] = -1;
+
+	for (i = 0; i < ARRAY_SIZE(intc->config_map.ch_to_host); i++)
+		intc->config_map.ch_to_host[i] = -1;
+
+	intc->pruss = platform_get_drvdata(ppdev);
+	pruss_intc_init(intc);
+
+	irqchip = devm_kzalloc(dev, sizeof(*irqchip), GFP_KERNEL);
+	if (!irqchip)
+		return -ENOMEM;
+
+	irqchip->irq_ack = pruss_intc_irq_ack;
+	irqchip->irq_mask = pruss_intc_irq_mask;
+	irqchip->irq_unmask = pruss_intc_irq_unmask;
+	irqchip->irq_retrigger = pruss_intc_irq_retrigger;
+	irqchip->irq_request_resources = pruss_intc_irq_reqres;
+	irqchip->irq_release_resources = pruss_intc_irq_relres;
+	irqchip->name = dev_name(dev);
+	intc->irqchip = irqchip;
+
+	/* always 64 events */
+	intc->domain = irq_domain_add_linear(dev->of_node, MAX_PRU_SYS_EVENTS,
+					     &pruss_intc_irq_domain_ops, intc);
+	if (!intc->domain)
+		return -ENOMEM;
+
+	for (i = 0; i < MAX_HOST_NUM_IRQS; i++) {
+		irq = platform_get_irq_byname(ppdev, irq_names[i]);
+		if (irq < 0) {
+			dev_err(dev->parent, "platform_get_irq_byname failed for %s : %d\n",
+				irq_names[i], irq);
+			goto fail_irq;
+		}
+
+		intc->irqs[i] = irq;
+		irq_set_handler_data(irq, intc);
+		irq_set_chained_handler(irq, pruss_intc_irq_handler);
+	}
+
+	return 0;
+
+fail_irq:
+	irq_domain_remove(intc->domain);
+	return irq;
+}
+
+static int pruss_intc_remove(struct platform_device *pdev)
+{
+	struct pruss_intc *intc = platform_get_drvdata(pdev);
+	unsigned int hwirq;
+
+	if (intc->domain) {
+		for (hwirq = 0; hwirq < MAX_PRU_SYS_EVENTS; hwirq++)
+			irq_dispose_mapping(irq_find_mapping(intc->domain,
+							     hwirq));
+		irq_domain_remove(intc->domain);
+	}
+
+	return 0;
+}
+
+static const struct of_device_id pruss_intc_of_match[] = {
+	{ .compatible = "ti,am3356-pruss-intc", },
+	{ /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, pruss_intc_of_match);
+
+static struct platform_driver pruss_intc_driver = {
+	.driver = {
+		.name = "pruss-intc",
+		.of_match_table = pruss_intc_of_match,
+	},
+	.probe  = pruss_intc_probe,
+	.remove = pruss_intc_remove,
+};
+module_platform_driver(pruss_intc_driver);
+
+MODULE_AUTHOR("Andrew F. Davis <afd@ti.com>");
+MODULE_AUTHOR("Suman Anna <s-anna@ti.com>");
+MODULE_DESCRIPTION("PRU-ICSS INTC Driver");
+MODULE_LICENSE("GPL v2");