[PATCH v8 0/2] irqchip: qcom: add support for PDC interrupt controller

[PATCH v8 0/2] irqchip: qcom: add support for PDC interrupt controller

[Lina Iyer]

Changes since v7:
	- fix whitespace alignment for multi-line statement
	- add Rob H 'reviewed-by' for DT bindings
	- rebase on top of 4.6-rc3

On newer Qualcomm Techonologies Inc's SoCs like the SDM845, the GIC is in a
power domain that can be powered off when not needed. Interrupts that need to
be sensed even when the GIC is powered off, are routed through an interrupt
controller in an always-on domain called the Power Domain Controller a.k.a PDC.
This series adds support for the PDC's interrupt controller.

Please consider reviewing these patches.

RFC v1: https://patchwork.kernel.org/patch/10180857/
RFC v2: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1600634.html
v3: https://lkml.org/lkml/2018/2/6/595
v4: https://www.spinics.net/lists/linux-arm-msm/msg32906.html
v5: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1605500.html
v6: https://lkml.org/lkml/2018/2/9/545
v7: https://www.spinics.net/lists/kernel/msg2723942.html

Lina Iyer (2):
  drivers: irqchip: pdc: Add PDC interrupt controller for QCOM SoCs
  dt-bindings/interrupt-controller: pdc: describe PDC device binding

 .../bindings/interrupt-controller/qcom,pdc.txt     |  78 ++++++
 drivers/irqchip/Kconfig                            |   9 +
 drivers/irqchip/Makefile                           |   1 +
 drivers/irqchip/qcom-pdc.c                         | 311 +++++++++++++++++++++
 4 files changed, 399 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.txt
 create mode 100644 drivers/irqchip/qcom-pdc.c

--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH v8 1/2] drivers: irqchip: pdc: Add PDC interrupt controller for QCOM SoCs

[Lina Iyer]

>From : Archana Sathyakumar <asathyak@codeaurora.org>

The Power Domain Controller (PDC) on QTI SoCs like SDM845 houses an
interrupt controller along with other domain control functions to handle
interrupt related functions like handle falling edge or active low which
are not detected at the GIC and handle wakeup interrupts.

The interrupt controller is on an always-on domain for the purpose of
waking up the processor. Only a subset of the processor's interrupts are
routed through the PDC to the GIC. The PDC powers on the processors'
domain, when in low power mode and replays pending interrupts so the GIC
may wake up the processor.

Signed-off-by: Archana Sathyakumar <asathyak@codeaurora.org>
Signed-off-by: Lina Iyer <ilina@codeaurora.org>
---
 drivers/irqchip/Kconfig    |   9 ++
 drivers/irqchip/Makefile   |   1 +
 drivers/irqchip/qcom-pdc.c | 311 +++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 321 insertions(+)
 create mode 100644 drivers/irqchip/qcom-pdc.c

diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
index d913aec85109..030c7753d45b 100644
--- a/drivers/irqchip/Kconfig
+++ b/drivers/irqchip/Kconfig
@@ -351,4 +351,13 @@ config GOLDFISH_PIC
          Say yes here to enable Goldfish interrupt controller driver used
          for Goldfish based virtual platforms.
 
+config QCOM_PDC
+	bool "QCOM PDC"
+	depends on ARCH_QCOM
+	select IRQ_DOMAIN
+	select IRQ_DOMAIN_HIERARCHY
+	help
+	  Power Domain Controller driver to manage and configure wakeup
+	  IRQs for Qualcomm Technologies Inc (QTI) mobile chips.
+
 endmenu
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index d27e3e3619e0..c35ee5345a53 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -85,3 +85,4 @@ obj-$(CONFIG_IRQ_UNIPHIER_AIDET)	+= irq-uniphier-aidet.o
 obj-$(CONFIG_ARCH_SYNQUACER)		+= irq-sni-exiu.o
 obj-$(CONFIG_MESON_IRQ_GPIO)		+= irq-meson-gpio.o
 obj-$(CONFIG_GOLDFISH_PIC) 		+= irq-goldfish-pic.o
+obj-$(CONFIG_QCOM_PDC)			+= qcom-pdc.o
diff --git a/drivers/irqchip/qcom-pdc.c b/drivers/irqchip/qcom-pdc.c
new file mode 100644
index 000000000000..b1b47a40a278
--- /dev/null
+++ b/drivers/irqchip/qcom-pdc.c
@@ -0,0 +1,311 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2017-2018, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/spinlock.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#define PDC_MAX_IRQS		126
+
+#define CLEAR_INTR(reg, intr)	(reg & ~(1 << intr))
+#define ENABLE_INTR(reg, intr)	(reg | (1 << intr))
+
+#define IRQ_ENABLE_BANK		0x10
+#define IRQ_i_CFG		0x110
+
+struct pdc_pin_region {
+	u32 pin_base;
+	u32 parent_base;
+	u32 cnt;
+};
+
+static DEFINE_RAW_SPINLOCK(pdc_lock);
+static void __iomem *pdc_base;
+static struct pdc_pin_region *pdc_region;
+static int pdc_region_cnt;
+
+static void pdc_reg_write(int reg, u32 i, u32 val)
+{
+	writel_relaxed(val, pdc_base + reg + i * sizeof(u32));
+}
+
+static u32 pdc_reg_read(int reg, u32 i)
+{
+	return readl_relaxed(pdc_base + reg + i * sizeof(u32));
+}
+
+static void pdc_enable_intr(struct irq_data *d, bool on)
+{
+	int pin_out = d->hwirq;
+	u32 index, mask;
+	u32 enable;
+
+	index = pin_out / 32;
+	mask = pin_out % 32;
+
+	raw_spin_lock(&pdc_lock);
+	enable = pdc_reg_read(IRQ_ENABLE_BANK, index);
+	enable = on ? ENABLE_INTR(enable, mask) : CLEAR_INTR(enable, mask);
+	pdc_reg_write(IRQ_ENABLE_BANK, index, enable);
+	raw_spin_unlock(&pdc_lock);
+}
+
+static void qcom_pdc_gic_mask(struct irq_data *d)
+{
+	pdc_enable_intr(d, false);
+	irq_chip_mask_parent(d);
+}
+
+static void qcom_pdc_gic_unmask(struct irq_data *d)
+{
+	pdc_enable_intr(d, true);
+	irq_chip_unmask_parent(d);
+}
+
+/*
+ * GIC does not handle falling edge or active low. To allow falling edge and
+ * active low interrupts to be handled at GIC, PDC has an inverter that inverts
+ * falling edge into a rising edge and active low into an active high.
+ * For the inverter to work, the polarity bit in the IRQ_CONFIG register has to
+ * set as per the table below.
+ * Level sensitive active low    LOW
+ * Rising edge sensitive         NOT USED
+ * Falling edge sensitive        LOW
+ * Dual Edge sensitive           NOT USED
+ * Level sensitive active High   HIGH
+ * Falling Edge sensitive        NOT USED
+ * Rising edge sensitive         HIGH
+ * Dual Edge sensitive           HIGH
+ */
+enum pdc_irq_config_bits {
+	PDC_LEVEL_LOW		= 0b000,
+	PDC_EDGE_FALLING	= 0b010,
+	PDC_LEVEL_HIGH		= 0b100,
+	PDC_EDGE_RISING		= 0b110,
+	PDC_EDGE_DUAL		= 0b111,
+};
+
+/**
+ * qcom_pdc_gic_set_type: Configure PDC for the interrupt
+ *
+ * @d: the interrupt data
+ * @type: the interrupt type
+ *
+ * If @type is edge triggered, forward that as Rising edge as PDC
+ * takes care of converting falling edge to rising edge signal
+ * If @type is level, then forward that as level high as PDC
+ * takes care of converting falling edge to rising edge signal
+ */
+static int qcom_pdc_gic_set_type(struct irq_data *d, unsigned int type)
+{
+	int pin_out = d->hwirq;
+	enum pdc_irq_config_bits pdc_type;
+
+	switch (type) {
+	case IRQ_TYPE_EDGE_RISING:
+		pdc_type = PDC_EDGE_RISING;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		pdc_type = PDC_EDGE_FALLING;
+		type = IRQ_TYPE_EDGE_RISING;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		pdc_type = PDC_EDGE_DUAL;
+		break;
+	case IRQ_TYPE_LEVEL_HIGH:
+		pdc_type = PDC_LEVEL_HIGH;
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		pdc_type = PDC_LEVEL_LOW;
+		type = IRQ_TYPE_LEVEL_HIGH;
+		break;
+	default:
+		WARN_ON(1);
+		return -EINVAL;
+	}
+
+	pdc_reg_write(IRQ_i_CFG, pin_out, pdc_type);
+
+	return irq_chip_set_type_parent(d, type);
+}
+
+static struct irq_chip qcom_pdc_gic_chip = {
+	.name			= "PDC",
+	.irq_eoi		= irq_chip_eoi_parent,
+	.irq_mask		= qcom_pdc_gic_mask,
+	.irq_unmask		= qcom_pdc_gic_unmask,
+	.irq_retrigger		= irq_chip_retrigger_hierarchy,
+	.irq_set_type		= qcom_pdc_gic_set_type,
+	.flags			= IRQCHIP_MASK_ON_SUSPEND |
+				  IRQCHIP_SET_TYPE_MASKED |
+				  IRQCHIP_SKIP_SET_WAKE,
+	.irq_set_vcpu_affinity	= irq_chip_set_vcpu_affinity_parent,
+	.irq_set_affinity	= irq_chip_set_affinity_parent,
+};
+
+static irq_hw_number_t get_parent_hwirq(int pin)
+{
+	int i;
+	struct pdc_pin_region *region;
+
+	for (i = 0; i < pdc_region_cnt; i++) {
+		region = &pdc_region[i];
+		if (pin >= region->pin_base &&
+		    pin < region->pin_base + region->cnt)
+			return (region->parent_base + pin - region->pin_base);
+	}
+
+	WARN_ON(1);
+	return ~0UL;
+}
+
+static int qcom_pdc_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
+			      unsigned long *hwirq, unsigned int *type)
+{
+	if (is_of_node(fwspec->fwnode)) {
+		if (fwspec->param_count != 2)
+			return -EINVAL;
+
+		*hwirq = fwspec->param[0];
+		*type = fwspec->param[1] & IRQ_TYPE_SENSE_MASK;
+		return 0;
+	}
+
+	return -EINVAL;
+}
+
+static int qcom_pdc_alloc(struct irq_domain *domain, unsigned int virq,
+			  unsigned int nr_irqs, void *data)
+{
+	struct irq_fwspec *fwspec = data;
+	struct irq_fwspec parent_fwspec;
+	irq_hw_number_t hwirq, parent_hwirq;
+	unsigned int type;
+	int ret;
+
+	ret = qcom_pdc_translate(domain, fwspec, &hwirq, &type);
+	if (ret)
+		return -EINVAL;
+
+	parent_hwirq = get_parent_hwirq(hwirq);
+	if (parent_hwirq == ~0UL)
+		return -EINVAL;
+
+	ret  = irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
+					     &qcom_pdc_gic_chip, NULL);
+	if (ret)
+		return ret;
+
+	if (type & IRQ_TYPE_EDGE_BOTH)
+		type = IRQ_TYPE_EDGE_RISING;
+
+	if (type & IRQ_TYPE_LEVEL_MASK)
+		type = IRQ_TYPE_LEVEL_HIGH;
+
+	parent_fwspec.fwnode      = domain->parent->fwnode;
+	parent_fwspec.param_count = 3;
+	parent_fwspec.param[0]    = 0;
+	parent_fwspec.param[1]    = parent_hwirq;
+	parent_fwspec.param[2]    = type;
+
+	return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
+					    &parent_fwspec);
+}
+
+static const struct irq_domain_ops qcom_pdc_ops = {
+	.translate	= qcom_pdc_translate,
+	.alloc		= qcom_pdc_alloc,
+	.free		= irq_domain_free_irqs_common,
+};
+
+static int pdc_setup_pin_mapping(struct device_node *np)
+{
+	int ret, n;
+
+	n = of_property_count_elems_of_size(np, "qcom,pdc-ranges", sizeof(u32));
+	if (n <= 0 || n % 3)
+		return -EINVAL;
+
+	pdc_region_cnt = n / 3;
+	pdc_region = kcalloc(pdc_region_cnt, sizeof(*pdc_region), GFP_KERNEL);
+	if (!pdc_region) {
+		pdc_region_cnt = 0;
+		return -ENOMEM;
+	}
+
+	for (n = 0; n < pdc_region_cnt; n++) {
+		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
+						 n * 3 + 0,
+						 &pdc_region[n].pin_base);
+		if (ret)
+			return ret;
+		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
+						 n * 3 + 1,
+						 &pdc_region[n].parent_base);
+		if (ret)
+			return ret;
+		ret = of_property_read_u32_index(np, "qcom,pdc-ranges",
+						 n * 3 + 2,
+						 &pdc_region[n].cnt);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static int qcom_pdc_init(struct device_node *node, struct device_node *parent)
+{
+	struct irq_domain *parent_domain, *pdc_domain;
+	int ret;
+
+	pdc_base = of_iomap(node, 0);
+	if (!pdc_base) {
+		pr_err("%pOF: unable to map PDC registers\n", node);
+		return -ENXIO;
+	}
+
+	parent_domain = irq_find_host(parent);
+	if (!parent_domain) {
+		pr_err("%pOF: unable to find PDC's parent domain\n", node);
+		ret = -ENXIO;
+		goto fail;
+	}
+
+	ret = pdc_setup_pin_mapping(node);
+	if (ret) {
+		pr_err("%pOF: failed to init PDC pin-hwirq mapping\n", node);
+		goto fail;
+	}
+
+	pdc_domain = irq_domain_create_hierarchy(parent_domain, 0, PDC_MAX_IRQS,
+						 of_fwnode_handle(node),
+						 &qcom_pdc_ops, NULL);
+	if (!pdc_domain) {
+		pr_err("%pOF: GIC domain add failed\n", node);
+		ret = -ENOMEM;
+		goto fail;
+	}
+
+	return 0;
+
+fail:
+	kfree(pdc_region);
+	iounmap(pdc_base);
+	return ret;
+}
+
+IRQCHIP_DECLARE(pdc_sdm845, "qcom,sdm845-pdc", qcom_pdc_init);
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

[PATCH v8 2/2] dt-bindings/interrupt-controller: pdc: describe PDC device binding

[Lina Iyer]

From: Archana Sathyakumar <asathyak@codeaurora.org>

Add device binding documentation for the PDC Interrupt controller on
QCOM SoC's like the SDM845. The interrupt-controller can be used to
sense edge low interrupts and wakeup interrupts when the GIC is
non-operational.

Cc: devicetree@vger.kernel.org
Signed-off-by: Archana Sathyakumar <asathyak@codeaurora.org>
Signed-off-by: Lina Iyer <ilina@codeaurora.org>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/interrupt-controller/qcom,pdc.txt     | 78 ++++++++++++++++++++++
 1 file changed, 78 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.txt

diff --git a/Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.txt b/Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.txt
new file mode 100644
index 000000000000..0b2c97ddb520
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/qcom,pdc.txt
@@ -0,0 +1,78 @@
+PDC interrupt controller
+
+Qualcomm Technologies Inc. SoCs based on the RPM Hardened architecture have a
+Power Domain Controller (PDC) that is on always-on domain. In addition to
+providing power control for the power domains, the hardware also has an
+interrupt controller that can be used to help detect edge low interrupts as
+well detect interrupts when the GIC is non-operational.
+
+GIC is parent interrupt controller at the highest level. Platform interrupt
+controller PDC is next in hierarchy, followed by others. Drivers requiring
+wakeup capabilities of their device interrupts routed through the PDC, must
+specify PDC as their interrupt controller and request the PDC port associated
+with the GIC interrupt. See example below.
+
+Properties:
+
+- compatible:
+	Usage: required
+	Value type: <string>
+	Definition: Should contain "qcom,<soc>-pdc"
+		    - "qcom,sdm845-pdc": For SDM845
+
+- reg:
+	Usage: required
+	Value type: <prop-encoded-array>
+	Definition: Specifies the base physical address for PDC hardware.
+
+- interrupt-cells:
+	Usage: required
+	Value type: <u32>
+	Definition: Specifies the number of cells needed to encode an interrupt
+		    source.
+		    Must be 2.
+		    The first element of the tuple is the PDC pin for the
+		    interrupt.
+		    The second element is the trigger type.
+
+- interrupt-parent:
+	Usage: required
+	Value type: <phandle>
+	Definition: Specifies the interrupt parent necessary for hierarchical
+		    domain to operate.
+
+- interrupt-controller:
+	Usage: required
+	Value type: <bool>
+	Definition: Identifies the node as an interrupt controller.
+
+- qcom,pdc-ranges:
+	Usage: required
+	Value type: <u32 array>
+	Definition: Specifies the PDC pin offset and the number of PDC ports.
+		    The tuples indicates the valid mapping of valid PDC ports
+		    and their hwirq mapping.
+		    The first element of the tuple is the starting PDC port.
+		    The second element is the GIC hwirq number for the PDC port.
+		    The third element is the number of interrupts in sequence.
+
+Example:
+
+	pdc: interrupt-controller@b220000 {
+		compatible = "qcom,sdm845-pdc";
+		reg = <0xb220000 0x30000>;
+		qcom,pdc-ranges = <0 512 94>, <94 641 15>, <115 662 7>;
+		#interrupt-cells = <2>;
+		interrupt-parent = <&intc>;
+		interrupt-controller;
+	};
+
+DT binding of a device that wants to use the GIC SPI 514 as a wakeup
+interrupt, must do -
+
+	wake-device {
+		interrupts-extended = <&pdc 2 IRQ_TYPE_LEVEL_HIGH>;
+	};
+
+In this case interrupt 514 would be mapped to port 2 on the PDC as defined by
+the qcom,pdc-ranges property.
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

Re: [PATCH v8 0/2] irqchip: qcom: add support for PDC interrupt controller

[Marc Zyngier]

On 28/02/18 17:27, Lina Iyer wrote:
> Changes since v7:
> 	- fix whitespace alignment for multi-line statement
> 	- add Rob H 'reviewed-by' for DT bindings
> 	- rebase on top of 4.6-rc3
> 
> On newer Qualcomm Techonologies Inc's SoCs like the SDM845, the GIC is in a
> power domain that can be powered off when not needed. Interrupts that need to
> be sensed even when the GIC is powered off, are routed through an interrupt
> controller in an always-on domain called the Power Domain Controller a.k.a PDC.
> This series adds support for the PDC's interrupt controller.
> 
> Please consider reviewing these patches.
> 
> RFC v1: https://patchwork.kernel.org/patch/10180857/
> RFC v2: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1600634.html
> v3: https://lkml.org/lkml/2018/2/6/595
> v4: https://www.spinics.net/lists/linux-arm-msm/msg32906.html
> v5: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1605500.html
> v6: https://lkml.org/lkml/2018/2/9/545
> v7: https://www.spinics.net/lists/kernel/msg2723942.html
> 
> Lina Iyer (2):
>   drivers: irqchip: pdc: Add PDC interrupt controller for QCOM SoCs
>   dt-bindings/interrupt-controller: pdc: describe PDC device binding

Queued for 4.17.

	M.
-- 
Jazz is not dead. It just smells funny...

Re: [PATCH v8 0/2] irqchip: qcom: add support for PDC interrupt controller

[Lina Iyer]

On Thu, Mar 01 2018 at 16:13 +0000, Marc Zyngier wrote:
>On 28/02/18 17:27, Lina Iyer wrote:
>> Changes since v7:
>> 	- fix whitespace alignment for multi-line statement
>> 	- add Rob H 'reviewed-by' for DT bindings
>> 	- rebase on top of 4.6-rc3
>>
>> On newer Qualcomm Techonologies Inc's SoCs like the SDM845, the GIC is in a
>> power domain that can be powered off when not needed. Interrupts that need to
>> be sensed even when the GIC is powered off, are routed through an interrupt
>> controller in an always-on domain called the Power Domain Controller a.k.a PDC.
>> This series adds support for the PDC's interrupt controller.
>>
>> Please consider reviewing these patches.
>>
>> RFC v1: https://patchwork.kernel.org/patch/10180857/
>> RFC v2: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1600634.html
>> v3: https://lkml.org/lkml/2018/2/6/595
>> v4: https://www.spinics.net/lists/linux-arm-msm/msg32906.html
>> v5: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1605500.html
>> v6: https://lkml.org/lkml/2018/2/9/545
>> v7: https://www.spinics.net/lists/kernel/msg2723942.html
>>
>> Lina Iyer (2):
>>   drivers: irqchip: pdc: Add PDC interrupt controller for QCOM SoCs
>>   dt-bindings/interrupt-controller: pdc: describe PDC device binding
>
>Queued for 4.17.
>
Thanks Marc.

-- Lina