diff mbox series

[v2,2/3] irqchip: Add Realtek RTD1295 mux driver

Message ID 20170828105344.8338-3-afaerber@suse.de
State New
Headers show
Series [v2,1/3] dt-bindings: interrupt-controller: Add Realtek RTD1295 | expand

Commit Message

Andreas Färber Aug. 28, 2017, 10:53 a.m. UTC
This irq mux driver is derived from the RTD1295 vendor DT and assumes a
linear mapping between intr_en and intr_status registers.
Code for RTD119x indicates this may not always be the case (i2c_3).

Based in part on QNAP's arch/arm/mach-rtk119x/rtk_irq_mux.c code.

Signed-off-by: Andreas Färber <afaerber@suse.de>

---
 v1 -> v2:
 * Renamed struct fields to avoid ambiguity (Marc)
 * Refactored offset lookup to avoid per-compatible init functions
 * Inserted white lines to clarify balanced locking (Marc)
 * Dropped forwarding of set_affinity to GIC (Marc)
 * Added spinlocks for consistency (Marc)
 * Limited initialization quirk to iso mux
 * Fixed spinlock initialization (Andrew)
 
 drivers/irqchip/Makefile          |   1 +
 drivers/irqchip/irq-rtd119x-mux.c | 204 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 205 insertions(+)
 create mode 100644 drivers/irqchip/irq-rtd119x-mux.c

-- 
2.12.3

Comments

Marc Zyngier Oct. 11, 2017, 5:35 p.m. UTC | #1
On 28/08/17 11:53, Andreas Färber wrote:
> This irq mux driver is derived from the RTD1295 vendor DT and assumes a

> linear mapping between intr_en and intr_status registers.

> Code for RTD119x indicates this may not always be the case (i2c_3).

> 

> Based in part on QNAP's arch/arm/mach-rtk119x/rtk_irq_mux.c code.

> 

> Signed-off-by: Andreas Färber <afaerber@suse.de>

> ---

>  v1 -> v2:

>  * Renamed struct fields to avoid ambiguity (Marc)

>  * Refactored offset lookup to avoid per-compatible init functions

>  * Inserted white lines to clarify balanced locking (Marc)

>  * Dropped forwarding of set_affinity to GIC (Marc)

>  * Added spinlocks for consistency (Marc)

>  * Limited initialization quirk to iso mux

>  * Fixed spinlock initialization (Andrew)

>  

>  drivers/irqchip/Makefile          |   1 +

>  drivers/irqchip/irq-rtd119x-mux.c | 204 ++++++++++++++++++++++++++++++++++++++

>  2 files changed, 205 insertions(+)

>  create mode 100644 drivers/irqchip/irq-rtd119x-mux.c

> 

> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile

> index e88d856cc09c..46202a0b7d96 100644

> --- a/drivers/irqchip/Makefile

> +++ b/drivers/irqchip/Makefile

> @@ -78,3 +78,4 @@ obj-$(CONFIG_EZNPS_GIC)			+= irq-eznps.o

>  obj-$(CONFIG_ARCH_ASPEED)		+= irq-aspeed-vic.o irq-aspeed-i2c-ic.o

>  obj-$(CONFIG_STM32_EXTI) 		+= irq-stm32-exti.o

>  obj-$(CONFIG_QCOM_IRQ_COMBINER)		+= qcom-irq-combiner.o

> +obj-$(CONFIG_ARCH_REALTEK)		+= irq-rtd119x-mux.o

> diff --git a/drivers/irqchip/irq-rtd119x-mux.c b/drivers/irqchip/irq-rtd119x-mux.c

> new file mode 100644

> index 000000000000..65d22e163bef

> --- /dev/null

> +++ b/drivers/irqchip/irq-rtd119x-mux.c

> @@ -0,0 +1,204 @@

> +/*

> + * Realtek RTD129x IRQ mux

> + *

> + * Copyright (c) 2017 Andreas Färber

> + *

> + * SPDX-License-Identifier: GPL-2.0+

> + */

> +

> +#include <linux/io.h>

> +#include <linux/irqchip.h>

> +#include <linux/irqchip/chained_irq.h>

> +#include <linux/irqdomain.h>

> +#include <linux/of_address.h>

> +#include <linux/of_irq.h>

> +#include <linux/slab.h>

> +

> +struct rtd119x_irq_mux_info {

> +	unsigned intr_status_offset;

> +	unsigned intr_en_offset;

> +};

> +

> +struct rtd119x_irq_mux_data {

> +	void __iomem *intr_status;

> +	void __iomem *intr_en;

> +	int irq;

> +	struct irq_domain *domain;

> +	spinlock_t lock;

> +};

> +

> +static void rtd119x_mux_irq_handle(struct irq_desc *desc)

> +{

> +	struct rtd119x_irq_mux_data *data = irq_desc_get_handler_data(desc);

> +	struct irq_chip *chip = irq_desc_get_chip(desc);

> +	u32 intr_en, intr_status, status;

> +	int ret;

> +

> +	chained_irq_enter(chip, desc);

> +

> +	spin_lock(&data->lock);

> +	intr_en     = readl(data->intr_en);


I think that all the MMIO accessors in this file can advantageously
turned into their _relaxed version (none of them require any barrier).

> +	intr_status = readl(data->intr_status);

> +	spin_unlock(&data->lock);

> +

> +	status = intr_status & intr_en;

> +	if (status != 0) {

> +		unsigned irq = __ffs(status);

> +		ret = generic_handle_irq(irq_find_mapping(data->domain, irq));

> +		if (ret == 0) {

> +			spin_lock(&data->lock);

> +

> +			intr_status = readl(data->intr_status);

> +			intr_status |= BIT(irq - 1);

> +			writel(intr_status, data->intr_status);


This sequence feels a bit wrong: It seems to imply that writing to the
status register is a way to EOI the interrupt. But what happens to the
other bits that you've read? I fear that you are inadvertently
signalling an EOI for interrupts that you may not have handled yet.

I'd rather see something like this:

	while (status) {
		irq = __ffs(status) - 1;
		writel_relaxed(BIT(irq), data->intr_status);
		generic_handle_irq(irq_find_mapping(data->domain, irq));
		status &= ~irq;
	}

assuming I've understood how the HW works. No need for additional locking.

> +

> +			spin_unlock(&data->lock);

> +		}

> +	}

> +

> +	chained_irq_exit(chip, desc);

> +}

> +

> +static void rtd119x_mux_mask_irq(struct irq_data *data)

> +{

> +	struct rtd119x_irq_mux_data *mux_data = irq_data_get_irq_chip_data(data);

> +	u32 intr_status;

> +

> +	spin_lock(&mux_data->lock);


Bang, you're dead. If you get the chained interrupt firing here on the
same CPU, it will take the lock in the above function, and everything
will grind to a halt. Use the irqsave version.

> +

> +	intr_status = readl(mux_data->intr_status);

> +	intr_status |= BIT(data->hwirq);

> +	writel(intr_status, mux_data->intr_status);


Or maybe I haven't understood how this works at all. Can you please
explain? I'd expect masking to be the opposite of unmasking, but that's
not the case...

> +

> +	spin_unlock(&mux_data->lock);

> +}

> +

> +static void rtd119x_mux_unmask_irq(struct irq_data *data)

> +{

> +	struct rtd119x_irq_mux_data *mux_data = irq_data_get_irq_chip_data(data);

> +	u32 intr_en;

> +

> +	spin_lock(&mux_data->lock);

> +


Same here.

> +	intr_en = readl(mux_data->intr_en);

> +	intr_en |= BIT(data->hwirq);

> +	writel(intr_en, mux_data->intr_en);

> +

> +	spin_unlock(&mux_data->lock);

> +}

> +

> +static int rtd119x_mux_set_affinity(struct irq_data *d,

> +			const struct cpumask *mask_val, bool force)

> +{

> +	/* Forwarding the affinity to the parent would affect all 32 interrupts. */

> +	return -EINVAL;

> +}

> +

> +static struct irq_chip rtd119x_mux_irq_chip = {

> +	.name			= "rtd119x-mux",

> +	.irq_mask		= rtd119x_mux_mask_irq,

> +	.irq_unmask		= rtd119x_mux_unmask_irq,

> +	.irq_set_affinity	= rtd119x_mux_set_affinity,

> +};

> +

> +static int rtd119x_mux_irq_domain_map(struct irq_domain *d,

> +		unsigned int irq, irq_hw_number_t hw)

> +{

> +	struct rtd119x_irq_mux_data *data = d->host_data;

> +

> +	irq_set_chip_and_handler(irq, &rtd119x_mux_irq_chip, handle_level_irq);

> +	irq_set_chip_data(irq, data);

> +	irq_set_probe(irq);

> +

> +	return 0;

> +}

> +

> +static struct irq_domain_ops rtd119x_mux_irq_domain_ops = {

> +	.xlate	= irq_domain_xlate_onecell,

> +	.map	= rtd119x_mux_irq_domain_map,

> +};

> +

> +static const struct rtd119x_irq_mux_info rtd1295_iso_irq_mux_info = {

> +	.intr_status_offset	= 0x0,

> +	.intr_en_offset		= 0x40,

> +};

> +

> +static const struct rtd119x_irq_mux_info rtd1295_irq_mux_info = {

> +	.intr_status_offset	= 0xc,

> +	.intr_en_offset		= 0x80,

> +};

> +

> +static const struct of_device_id rtd1295_irq_mux_dt_matches[] = {

> +	{

> +		.compatible = "realtek,rtd1295-iso-irq-mux",

> +		.data = &rtd1295_iso_irq_mux_info,

> +	}, {

> +		.compatible = "realtek,rtd1295-irq-mux",

> +		.data = &rtd1295_irq_mux_info,

> +	}, {

> +	}

> +};

> +

> +static int __init rtd119x_irq_mux_init(struct device_node *node,

> +				       struct device_node *parent)

> +{

> +	struct rtd119x_irq_mux_data *data;

> +	const struct of_device_id *match;

> +	const struct rtd119x_irq_mux_info *info;

> +	void __iomem *base;

> +	u32 val;

> +

> +	match = of_match_node(rtd1295_irq_mux_dt_matches, node);

> +	if (!match)

> +		return -EINVAL;

> +

> +	info = match->data;

> +	if (!info)

> +		return -EINVAL;

> +

> +	base = of_iomap(node, 0);

> +	if (IS_ERR(base))

> +		return PTR_ERR(base);

> +

> +	data = kzalloc(sizeof(*data), GFP_KERNEL);

> +	if (!data)

> +		return -ENOMEM;

> +

> +	data->intr_status = base + info->intr_status_offset;

> +	data->intr_en     = base + info->intr_en_offset;

> +

> +	data->irq = irq_of_parse_and_map(node, 0);

> +	if (data->irq <= 0) {

> +		kfree(data);

> +		return -EINVAL;

> +	}

> +

> +	spin_lock_init(&data->lock);

> +

> +	data->domain = irq_domain_add_linear(node, 32,

> +				&rtd119x_mux_irq_domain_ops, data);

> +	if (!data->domain) {

> +		kfree(data);

> +		return -ENOMEM;

> +	}

> +

> +	if (of_device_is_compatible(node, "realtek,rtd1295-iso-irq-mux")) {

> +		const int uart0_irq = 2;

> +

> +		spin_lock(&data->lock);

> +

> +		val = readl(data->intr_en);

> +		val &= ~BIT(uart0_irq);

> +		writel(val, data->intr_en);

> +

> +		writel(BIT(uart0_irq), data->intr_status);


Same here. Can you please explain what you're trying to do? The locking
seems a bit pointless (nobody can request the interrupt yet), and this
uart0 needs at least a comment, and maybe a description in the device-tree.

> +

> +		spin_unlock(&data->lock);

> +	}

> +

> +	irq_set_chained_handler_and_data(data->irq, rtd119x_mux_irq_handle, data);

> +

> +	return 0;

> +}

> +IRQCHIP_DECLARE(rtd1295_iso_mux, "realtek,rtd1295-iso-irq-mux", rtd119x_irq_mux_init);

> +IRQCHIP_DECLARE(rtd1295_mux, "realtek,rtd1295-irq-mux", rtd119x_irq_mux_init);

> 


Thanks,

	M.
-- 
Jazz is not dead. It just smells funny...
Andreas Färber Oct. 17, 2017, 11:50 a.m. UTC | #2
Am 11.10.2017 um 19:35 schrieb Marc Zyngier:
> On 28/08/17 11:53, Andreas Färber wrote:

>> This irq mux driver is derived from the RTD1295 vendor DT and assumes a

>> linear mapping between intr_en and intr_status registers.

>> Code for RTD119x indicates this may not always be the case (i2c_3).

>>

>> Based in part on QNAP's arch/arm/mach-rtk119x/rtk_irq_mux.c code.

>>

>> Signed-off-by: Andreas Färber <afaerber@suse.de>

>> ---

>>  v1 -> v2:

>>  * Renamed struct fields to avoid ambiguity (Marc)

>>  * Refactored offset lookup to avoid per-compatible init functions

>>  * Inserted white lines to clarify balanced locking (Marc)

>>  * Dropped forwarding of set_affinity to GIC (Marc)

>>  * Added spinlocks for consistency (Marc)

>>  * Limited initialization quirk to iso mux

>>  * Fixed spinlock initialization (Andrew)

>>  

>>  drivers/irqchip/Makefile          |   1 +

>>  drivers/irqchip/irq-rtd119x-mux.c | 204 ++++++++++++++++++++++++++++++++++++++

>>  2 files changed, 205 insertions(+)

>>  create mode 100644 drivers/irqchip/irq-rtd119x-mux.c

>>

>> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile

>> index e88d856cc09c..46202a0b7d96 100644

>> --- a/drivers/irqchip/Makefile

>> +++ b/drivers/irqchip/Makefile

>> @@ -78,3 +78,4 @@ obj-$(CONFIG_EZNPS_GIC)			+= irq-eznps.o

>>  obj-$(CONFIG_ARCH_ASPEED)		+= irq-aspeed-vic.o irq-aspeed-i2c-ic.o

>>  obj-$(CONFIG_STM32_EXTI) 		+= irq-stm32-exti.o

>>  obj-$(CONFIG_QCOM_IRQ_COMBINER)		+= qcom-irq-combiner.o

>> +obj-$(CONFIG_ARCH_REALTEK)		+= irq-rtd119x-mux.o

>> diff --git a/drivers/irqchip/irq-rtd119x-mux.c b/drivers/irqchip/irq-rtd119x-mux.c

>> new file mode 100644

>> index 000000000000..65d22e163bef

>> --- /dev/null

>> +++ b/drivers/irqchip/irq-rtd119x-mux.c

>> @@ -0,0 +1,204 @@

>> +/*

>> + * Realtek RTD129x IRQ mux

>> + *

>> + * Copyright (c) 2017 Andreas Färber

>> + *

>> + * SPDX-License-Identifier: GPL-2.0+

>> + */

>> +

>> +#include <linux/io.h>

>> +#include <linux/irqchip.h>

>> +#include <linux/irqchip/chained_irq.h>

>> +#include <linux/irqdomain.h>

>> +#include <linux/of_address.h>

>> +#include <linux/of_irq.h>

>> +#include <linux/slab.h>

>> +

>> +struct rtd119x_irq_mux_info {

>> +	unsigned intr_status_offset;

>> +	unsigned intr_en_offset;

>> +};

>> +

>> +struct rtd119x_irq_mux_data {

>> +	void __iomem *intr_status;

>> +	void __iomem *intr_en;

>> +	int irq;

>> +	struct irq_domain *domain;

>> +	spinlock_t lock;

>> +};

>> +

>> +static void rtd119x_mux_irq_handle(struct irq_desc *desc)

>> +{

>> +	struct rtd119x_irq_mux_data *data = irq_desc_get_handler_data(desc);

>> +	struct irq_chip *chip = irq_desc_get_chip(desc);

>> +	u32 intr_en, intr_status, status;

>> +	int ret;

>> +

>> +	chained_irq_enter(chip, desc);

>> +

>> +	spin_lock(&data->lock);

>> +	intr_en     = readl(data->intr_en);

> 

> I think that all the MMIO accessors in this file can advantageously

> turned into their _relaxed version (none of them require any barrier).


Done, works okay.

>> +	intr_status = readl(data->intr_status);

>> +	spin_unlock(&data->lock);

>> +

>> +	status = intr_status & intr_en;

>> +	if (status != 0) {

>> +		unsigned irq = __ffs(status);

>> +		ret = generic_handle_irq(irq_find_mapping(data->domain, irq));

>> +		if (ret == 0) {

>> +			spin_lock(&data->lock);

>> +

>> +			intr_status = readl(data->intr_status);

>> +			intr_status |= BIT(irq - 1);

>> +			writel(intr_status, data->intr_status);

> 

> This sequence feels a bit wrong: It seems to imply that writing to the

> status register is a way to EOI the interrupt. But what happens to the

> other bits that you've read? I fear that you are inadvertently

> signalling an EOI for interrupts that you may not have handled yet.

> 

> I'd rather see something like this:

> 

> 	while (status) {

> 		irq = __ffs(status) - 1;

> 		writel_relaxed(BIT(irq), data->intr_status);

> 		generic_handle_irq(irq_find_mapping(data->domain, irq));

> 		status &= ~irq;

> 	}

> 

> assuming I've understood how the HW works. No need for additional locking.


I've adopted a similar loop from the RTD1296 code, which differs from
the old RTD1195 code, which was like the above.

Similarly, the UART does a simple write for ack but the RTD1195's
fallback code here did the read-modify-write cycle. RTD129x removed that
fallback apparently.

I've reworked the code to use register names found in RTD1195 headers,
which will hopefully clarify things as far as there is code. I did not
find any code actually using the *_UMSK_ISR register, only *_ISR and
*_SCPU_INT_EN.

>> +

>> +			spin_unlock(&data->lock);

>> +		}

>> +	}

>> +

>> +	chained_irq_exit(chip, desc);

>> +}

>> +

>> +static void rtd119x_mux_mask_irq(struct irq_data *data)

>> +{

>> +	struct rtd119x_irq_mux_data *mux_data = irq_data_get_irq_chip_data(data);

>> +	u32 intr_status;

>> +

>> +	spin_lock(&mux_data->lock);

> 

> Bang, you're dead. If you get the chained interrupt firing here on the

> same CPU, it will take the lock in the above function, and everything

> will grind to a halt. Use the irqsave version.


Done.

> 

>> +

>> +	intr_status = readl(mux_data->intr_status);

>> +	intr_status |= BIT(data->hwirq);

>> +	writel(intr_status, mux_data->intr_status);

> 

> Or maybe I haven't understood how this works at all. Can you please

> explain? I'd expect masking to be the opposite of unmasking, but that's

> not the case...


Again, I have no documentation, just like you, so I cannot definitively
explain their hardware. Only downstream code and experiments. I've been
testing it with serial console and I²C access to PMIC.

>> +

>> +	spin_unlock(&mux_data->lock);

>> +}

>> +

>> +static void rtd119x_mux_unmask_irq(struct irq_data *data)

>> +{

>> +	struct rtd119x_irq_mux_data *mux_data = irq_data_get_irq_chip_data(data);

>> +	u32 intr_en;

>> +

>> +	spin_lock(&mux_data->lock);

>> +

> 

> Same here.

> 

>> +	intr_en = readl(mux_data->intr_en);

>> +	intr_en |= BIT(data->hwirq);

>> +	writel(intr_en, mux_data->intr_en);

>> +

>> +	spin_unlock(&mux_data->lock);

>> +}

>> +

>> +static int rtd119x_mux_set_affinity(struct irq_data *d,

>> +			const struct cpumask *mask_val, bool force)

>> +{

>> +	/* Forwarding the affinity to the parent would affect all 32 interrupts. */

>> +	return -EINVAL;

>> +}

>> +

>> +static struct irq_chip rtd119x_mux_irq_chip = {

>> +	.name			= "rtd119x-mux",

>> +	.irq_mask		= rtd119x_mux_mask_irq,

>> +	.irq_unmask		= rtd119x_mux_unmask_irq,

>> +	.irq_set_affinity	= rtd119x_mux_set_affinity,

>> +};

>> +

>> +static int rtd119x_mux_irq_domain_map(struct irq_domain *d,

>> +		unsigned int irq, irq_hw_number_t hw)

>> +{

>> +	struct rtd119x_irq_mux_data *data = d->host_data;

>> +

>> +	irq_set_chip_and_handler(irq, &rtd119x_mux_irq_chip, handle_level_irq);

>> +	irq_set_chip_data(irq, data);

>> +	irq_set_probe(irq);

>> +

>> +	return 0;

>> +}

>> +

>> +static struct irq_domain_ops rtd119x_mux_irq_domain_ops = {

>> +	.xlate	= irq_domain_xlate_onecell,

>> +	.map	= rtd119x_mux_irq_domain_map,

>> +};

>> +

>> +static const struct rtd119x_irq_mux_info rtd1295_iso_irq_mux_info = {

>> +	.intr_status_offset	= 0x0,

>> +	.intr_en_offset		= 0x40,

>> +};

>> +

>> +static const struct rtd119x_irq_mux_info rtd1295_irq_mux_info = {

>> +	.intr_status_offset	= 0xc,

>> +	.intr_en_offset		= 0x80,

>> +};

>> +

>> +static const struct of_device_id rtd1295_irq_mux_dt_matches[] = {

>> +	{

>> +		.compatible = "realtek,rtd1295-iso-irq-mux",

>> +		.data = &rtd1295_iso_irq_mux_info,

>> +	}, {

>> +		.compatible = "realtek,rtd1295-irq-mux",

>> +		.data = &rtd1295_irq_mux_info,

>> +	}, {

>> +	}

>> +};

>> +

>> +static int __init rtd119x_irq_mux_init(struct device_node *node,

>> +				       struct device_node *parent)

>> +{

>> +	struct rtd119x_irq_mux_data *data;

>> +	const struct of_device_id *match;

>> +	const struct rtd119x_irq_mux_info *info;

>> +	void __iomem *base;

>> +	u32 val;

>> +

>> +	match = of_match_node(rtd1295_irq_mux_dt_matches, node);

>> +	if (!match)

>> +		return -EINVAL;

>> +

>> +	info = match->data;

>> +	if (!info)

>> +		return -EINVAL;

>> +

>> +	base = of_iomap(node, 0);

>> +	if (IS_ERR(base))

>> +		return PTR_ERR(base);

>> +

>> +	data = kzalloc(sizeof(*data), GFP_KERNEL);

>> +	if (!data)

>> +		return -ENOMEM;

>> +

>> +	data->intr_status = base + info->intr_status_offset;

>> +	data->intr_en     = base + info->intr_en_offset;

>> +

>> +	data->irq = irq_of_parse_and_map(node, 0);

>> +	if (data->irq <= 0) {

>> +		kfree(data);

>> +		return -EINVAL;

>> +	}

>> +

>> +	spin_lock_init(&data->lock);

>> +

>> +	data->domain = irq_domain_add_linear(node, 32,

>> +				&rtd119x_mux_irq_domain_ops, data);

>> +	if (!data->domain) {

>> +		kfree(data);

>> +		return -ENOMEM;

>> +	}

>> +

>> +	if (of_device_is_compatible(node, "realtek,rtd1295-iso-irq-mux")) {

>> +		const int uart0_irq = 2;

>> +

>> +		spin_lock(&data->lock);

>> +

>> +		val = readl(data->intr_en);

>> +		val &= ~BIT(uart0_irq);

>> +		writel(val, data->intr_en);

>> +

>> +		writel(BIT(uart0_irq), data->intr_status);

> 

> Same here. Can you please explain what you're trying to do? The locking

> seems a bit pointless (nobody can request the interrupt yet), and this

> uart0 needs at least a comment, and maybe a description in the device-tree.


Please see v1... downstream has it unconditionally for both iso and
misc. I'm adding a comment that this resolves a hang.
I can drop the lock, was locking all register accesses for consistency.

>> +

>> +		spin_unlock(&data->lock);

>> +	}

>> +

>> +	irq_set_chained_handler_and_data(data->irq, rtd119x_mux_irq_handle, data);

>> +

>> +	return 0;

>> +}

>> +IRQCHIP_DECLARE(rtd1295_iso_mux, "realtek,rtd1295-iso-irq-mux", rtd119x_irq_mux_init);

>> +IRQCHIP_DECLARE(rtd1295_mux, "realtek,rtd1295-irq-mux", rtd119x_irq_mux_init);


Thanks for getting back to this. Note that this driver is needed both
for UART and I²C, and no lock-ups have been observed so far. So let's
please try to tidy this up sufficiently for merging into 4.15, so that
we can flush some more of the 100+ patches on top.

Regards,
Andreas

-- 
SUSE Linux GmbH, Maxfeldstr. 5, 90409 Nürnberg, Germany
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
diff mbox series

Patch

diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index e88d856cc09c..46202a0b7d96 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -78,3 +78,4 @@  obj-$(CONFIG_EZNPS_GIC)			+= irq-eznps.o
 obj-$(CONFIG_ARCH_ASPEED)		+= irq-aspeed-vic.o irq-aspeed-i2c-ic.o
 obj-$(CONFIG_STM32_EXTI) 		+= irq-stm32-exti.o
 obj-$(CONFIG_QCOM_IRQ_COMBINER)		+= qcom-irq-combiner.o
+obj-$(CONFIG_ARCH_REALTEK)		+= irq-rtd119x-mux.o
diff --git a/drivers/irqchip/irq-rtd119x-mux.c b/drivers/irqchip/irq-rtd119x-mux.c
new file mode 100644
index 000000000000..65d22e163bef
--- /dev/null
+++ b/drivers/irqchip/irq-rtd119x-mux.c
@@ -0,0 +1,204 @@ 
+/*
+ * Realtek RTD129x IRQ mux
+ *
+ * Copyright (c) 2017 Andreas Färber
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <linux/io.h>
+#include <linux/irqchip.h>
+#include <linux/irqchip/chained_irq.h>
+#include <linux/irqdomain.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/slab.h>
+
+struct rtd119x_irq_mux_info {
+	unsigned intr_status_offset;
+	unsigned intr_en_offset;
+};
+
+struct rtd119x_irq_mux_data {
+	void __iomem *intr_status;
+	void __iomem *intr_en;
+	int irq;
+	struct irq_domain *domain;
+	spinlock_t lock;
+};
+
+static void rtd119x_mux_irq_handle(struct irq_desc *desc)
+{
+	struct rtd119x_irq_mux_data *data = irq_desc_get_handler_data(desc);
+	struct irq_chip *chip = irq_desc_get_chip(desc);
+	u32 intr_en, intr_status, status;
+	int ret;
+
+	chained_irq_enter(chip, desc);
+
+	spin_lock(&data->lock);
+	intr_en     = readl(data->intr_en);
+	intr_status = readl(data->intr_status);
+	spin_unlock(&data->lock);
+
+	status = intr_status & intr_en;
+	if (status != 0) {
+		unsigned irq = __ffs(status);
+		ret = generic_handle_irq(irq_find_mapping(data->domain, irq));
+		if (ret == 0) {
+			spin_lock(&data->lock);
+
+			intr_status = readl(data->intr_status);
+			intr_status |= BIT(irq - 1);
+			writel(intr_status, data->intr_status);
+
+			spin_unlock(&data->lock);
+		}
+	}
+
+	chained_irq_exit(chip, desc);
+}
+
+static void rtd119x_mux_mask_irq(struct irq_data *data)
+{
+	struct rtd119x_irq_mux_data *mux_data = irq_data_get_irq_chip_data(data);
+	u32 intr_status;
+
+	spin_lock(&mux_data->lock);
+
+	intr_status = readl(mux_data->intr_status);
+	intr_status |= BIT(data->hwirq);
+	writel(intr_status, mux_data->intr_status);
+
+	spin_unlock(&mux_data->lock);
+}
+
+static void rtd119x_mux_unmask_irq(struct irq_data *data)
+{
+	struct rtd119x_irq_mux_data *mux_data = irq_data_get_irq_chip_data(data);
+	u32 intr_en;
+
+	spin_lock(&mux_data->lock);
+
+	intr_en = readl(mux_data->intr_en);
+	intr_en |= BIT(data->hwirq);
+	writel(intr_en, mux_data->intr_en);
+
+	spin_unlock(&mux_data->lock);
+}
+
+static int rtd119x_mux_set_affinity(struct irq_data *d,
+			const struct cpumask *mask_val, bool force)
+{
+	/* Forwarding the affinity to the parent would affect all 32 interrupts. */
+	return -EINVAL;
+}
+
+static struct irq_chip rtd119x_mux_irq_chip = {
+	.name			= "rtd119x-mux",
+	.irq_mask		= rtd119x_mux_mask_irq,
+	.irq_unmask		= rtd119x_mux_unmask_irq,
+	.irq_set_affinity	= rtd119x_mux_set_affinity,
+};
+
+static int rtd119x_mux_irq_domain_map(struct irq_domain *d,
+		unsigned int irq, irq_hw_number_t hw)
+{
+	struct rtd119x_irq_mux_data *data = d->host_data;
+
+	irq_set_chip_and_handler(irq, &rtd119x_mux_irq_chip, handle_level_irq);
+	irq_set_chip_data(irq, data);
+	irq_set_probe(irq);
+
+	return 0;
+}
+
+static struct irq_domain_ops rtd119x_mux_irq_domain_ops = {
+	.xlate	= irq_domain_xlate_onecell,
+	.map	= rtd119x_mux_irq_domain_map,
+};
+
+static const struct rtd119x_irq_mux_info rtd1295_iso_irq_mux_info = {
+	.intr_status_offset	= 0x0,
+	.intr_en_offset		= 0x40,
+};
+
+static const struct rtd119x_irq_mux_info rtd1295_irq_mux_info = {
+	.intr_status_offset	= 0xc,
+	.intr_en_offset		= 0x80,
+};
+
+static const struct of_device_id rtd1295_irq_mux_dt_matches[] = {
+	{
+		.compatible = "realtek,rtd1295-iso-irq-mux",
+		.data = &rtd1295_iso_irq_mux_info,
+	}, {
+		.compatible = "realtek,rtd1295-irq-mux",
+		.data = &rtd1295_irq_mux_info,
+	}, {
+	}
+};
+
+static int __init rtd119x_irq_mux_init(struct device_node *node,
+				       struct device_node *parent)
+{
+	struct rtd119x_irq_mux_data *data;
+	const struct of_device_id *match;
+	const struct rtd119x_irq_mux_info *info;
+	void __iomem *base;
+	u32 val;
+
+	match = of_match_node(rtd1295_irq_mux_dt_matches, node);
+	if (!match)
+		return -EINVAL;
+
+	info = match->data;
+	if (!info)
+		return -EINVAL;
+
+	base = of_iomap(node, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	data = kzalloc(sizeof(*data), GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	data->intr_status = base + info->intr_status_offset;
+	data->intr_en     = base + info->intr_en_offset;
+
+	data->irq = irq_of_parse_and_map(node, 0);
+	if (data->irq <= 0) {
+		kfree(data);
+		return -EINVAL;
+	}
+
+	spin_lock_init(&data->lock);
+
+	data->domain = irq_domain_add_linear(node, 32,
+				&rtd119x_mux_irq_domain_ops, data);
+	if (!data->domain) {
+		kfree(data);
+		return -ENOMEM;
+	}
+
+	if (of_device_is_compatible(node, "realtek,rtd1295-iso-irq-mux")) {
+		const int uart0_irq = 2;
+
+		spin_lock(&data->lock);
+
+		val = readl(data->intr_en);
+		val &= ~BIT(uart0_irq);
+		writel(val, data->intr_en);
+
+		writel(BIT(uart0_irq), data->intr_status);
+
+		spin_unlock(&data->lock);
+	}
+
+	irq_set_chained_handler_and_data(data->irq, rtd119x_mux_irq_handle, data);
+
+	return 0;
+}
+IRQCHIP_DECLARE(rtd1295_iso_mux, "realtek,rtd1295-iso-irq-mux", rtd119x_irq_mux_init);
+IRQCHIP_DECLARE(rtd1295_mux, "realtek,rtd1295-irq-mux", rtd119x_irq_mux_init);