drivers/irqchip/qcom-irq-combiner.c - linux - Git at Google

 /* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 and
  * only version 2 as published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  */

 /*
  * Driver for interrupt combiners in the Top-level Control and Status
  * Registers (TCSR) hardware block in Qualcomm Technologies chips.
  * An interrupt combiner in this block combines a set of interrupts by
  * OR'ing the individual interrupt signals into a summary interrupt
  * signal routed to a parent interrupt controller, and provides read-
  * only, 32-bit registers to query the status of individual interrupts.
  * The status bit for IRQ n is bit (n % 32) within register (n / 32)
  * of the given combiner. Thus, each combiner can be described as a set
  * of register offsets and the number of IRQs managed.
  */

 #define pr_fmt(fmt) "QCOM80B1:" fmt

 #include <linux/acpi.h>
 #include <linux/irqchip/chained_irq.h>
 #include <linux/irqdomain.h>
 #include <linux/platform_device.h>

 #define REG_SIZE 32

 struct combiner_reg {
 	void __iomem *addr;
 	unsigned long enabled;
 };

 struct combiner {
 	struct irq_domain   *domain;
 	int                 parent_irq;
 	u32                 nirqs;
 	u32                 nregs;
 	struct combiner_reg regs[0];
 };

 static inline int irq_nr(u32 reg, u32 bit)
 {
 	return reg * REG_SIZE + bit;
 }

 /*
  * Handler for the cascaded IRQ.
  */
 static void combiner_handle_irq(struct irq_desc *desc)
 {
 	struct combiner *combiner = irq_desc_get_handler_data(desc);
 	struct irq_chip *chip = irq_desc_get_chip(desc);
 	u32 reg;

 	chained_irq_enter(chip, desc);

 	for (reg = 0; reg < combiner->nregs; reg++) {
 		int virq;
 		int hwirq;
 		u32 bit;
 		u32 status;

 		bit = readl_relaxed(combiner->regs[reg].addr);
 		status = bit & combiner->regs[reg].enabled;
 		if (bit && !status)
 			pr_warn_ratelimited("Unexpected IRQ on CPU%d: (%08x %08lx %p)\n",
 					    smp_processor_id(), bit,
 					    combiner->regs[reg].enabled,
 					    combiner->regs[reg].addr);

 		while (status) {
 			bit = __ffs(status);
 			status &= ~(1 << bit);
 			hwirq = irq_nr(reg, bit);
 			virq = irq_find_mapping(combiner->domain, hwirq);
 			if (virq > 0)
 				generic_handle_irq(virq);

 		}
 	}

 	chained_irq_exit(chip, desc);
 }

 static void combiner_irq_chip_mask_irq(struct irq_data *data)
 {
 	struct combiner *combiner = irq_data_get_irq_chip_data(data);
 	struct combiner_reg *reg = combiner->regs + data->hwirq / REG_SIZE;

 	clear_bit(data->hwirq % REG_SIZE, &reg->enabled);
 }

 static void combiner_irq_chip_unmask_irq(struct irq_data *data)
 {
 	struct combiner *combiner = irq_data_get_irq_chip_data(data);
 	struct combiner_reg *reg = combiner->regs + data->hwirq / REG_SIZE;

 	set_bit(data->hwirq % REG_SIZE, &reg->enabled);
 }

 static struct irq_chip irq_chip = {
 	.irq_mask = combiner_irq_chip_mask_irq,
 	.irq_unmask = combiner_irq_chip_unmask_irq,
 	.name = "qcom-irq-combiner"
 };

 static int combiner_irq_map(struct irq_domain *domain, unsigned int irq,
 				   irq_hw_number_t hwirq)
 {
 	irq_set_chip_and_handler(irq, &irq_chip, handle_level_irq);
 	irq_set_chip_data(irq, domain->host_data);
 	irq_set_noprobe(irq);
 	return 0;
 }

 static void combiner_irq_unmap(struct irq_domain *domain, unsigned int irq)
 {
 	irq_domain_reset_irq_data(irq_get_irq_data(irq));
 }

 static int combiner_irq_translate(struct irq_domain *d, struct irq_fwspec *fws,
 				  unsigned long *hwirq, unsigned int *type)
 {
 	struct combiner *combiner = d->host_data;

 	if (is_acpi_node(fws->fwnode)) {
 		if (WARN_ON((fws->param_count != 2) ||
 			    (fws->param[0] >= combiner->nirqs) ||
 			    (fws->param[1] & IORESOURCE_IRQ_LOWEDGE) ||
 			    (fws->param[1] & IORESOURCE_IRQ_HIGHEDGE)))
 			return -EINVAL;

 		*hwirq = fws->param[0];
 		*type = fws->param[1];
 		return 0;
 	}

 	return -EINVAL;
 }

 static const struct irq_domain_ops domain_ops = {
 	.map = combiner_irq_map,
 	.unmap = combiner_irq_unmap,
 	.translate = combiner_irq_translate
 };

 static acpi_status count_registers_cb(struct acpi_resource *ares, void *context)
 {
 	int *count = context;

 	if (ares->type == ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
 		++(*count);
 	return AE_OK;
 }

 static int count_registers(struct platform_device *pdev)
 {
 	acpi_handle ahandle = ACPI_HANDLE(&pdev->dev);
 	acpi_status status;
 	int count = 0;

 	if (!acpi_has_method(ahandle, METHOD_NAME__CRS))
 		return -EINVAL;

 	status = acpi_walk_resources(ahandle, METHOD_NAME__CRS,
 				     count_registers_cb, &count);
 	if (ACPI_FAILURE(status))
 		return -EINVAL;
 	return count;
 }

 struct get_registers_context {
 	struct device *dev;
 	struct combiner *combiner;
 	int err;
 };

 static acpi_status get_registers_cb(struct acpi_resource *ares, void *context)
 {
 	struct get_registers_context *ctx = context;
 	struct acpi_resource_generic_register *reg;
 	phys_addr_t paddr;
 	void __iomem *vaddr;

 	if (ares->type != ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
 		return AE_OK;

 	reg = &ares->data.generic_reg;
 	paddr = reg->address;
 	if ((reg->space_id != ACPI_SPACE_MEM) ||
 	    (reg->bit_offset != 0) ||
 	    (reg->bit_width > REG_SIZE)) {
 		dev_err(ctx->dev, "Bad register resource @%pa\n", &paddr);
 		ctx->err = -EINVAL;
 		return AE_ERROR;
 	}

 	vaddr = devm_ioremap(ctx->dev, reg->address, REG_SIZE);
 	if (!vaddr) {
 		dev_err(ctx->dev, "Can't map register @%pa\n", &paddr);
 		ctx->err = -ENOMEM;
 		return AE_ERROR;
 	}

 	ctx->combiner->regs[ctx->combiner->nregs].addr = vaddr;
 	ctx->combiner->nirqs += reg->bit_width;
 	ctx->combiner->nregs++;
 	return AE_OK;
 }

 static int get_registers(struct platform_device *pdev, struct combiner *comb)
 {
 	acpi_handle ahandle = ACPI_HANDLE(&pdev->dev);
 	acpi_status status;
 	struct get_registers_context ctx;

 	if (!acpi_has_method(ahandle, METHOD_NAME__CRS))
 		return -EINVAL;

 	ctx.dev = &pdev->dev;
 	ctx.combiner = comb;
 	ctx.err = 0;

 	status = acpi_walk_resources(ahandle, METHOD_NAME__CRS,
 				     get_registers_cb, &ctx);
 	if (ACPI_FAILURE(status))
 		return ctx.err;
 	return 0;
 }

 static int __init combiner_probe(struct platform_device *pdev)
 {
 	struct combiner *combiner;
 	size_t alloc_sz;
 	int nregs;
 	int err;

 	nregs = count_registers(pdev);
 	if (nregs <= 0) {
 		dev_err(&pdev->dev, "Error reading register resources\n");
 		return -EINVAL;
 	}

 	alloc_sz = sizeof(*combiner) + sizeof(struct combiner_reg) * nregs;
 	combiner = devm_kzalloc(&pdev->dev, alloc_sz, GFP_KERNEL);
 	if (!combiner)
 		return -ENOMEM;

 	err = get_registers(pdev, combiner);
 	if (err < 0)
 		return err;

 	combiner->parent_irq = platform_get_irq(pdev, 0);
 	if (combiner->parent_irq <= 0) {
 		dev_err(&pdev->dev, "Error getting IRQ resource\n");
 		return -EPROBE_DEFER;
 	}

 	combiner->domain = irq_domain_create_linear(pdev->dev.fwnode, combiner->nirqs,
 						    &domain_ops, combiner);
 	if (!combiner->domain)
 		/* Errors printed by irq_domain_create_linear */
 		return -ENODEV;

 	irq_set_chained_handler_and_data(combiner->parent_irq,
 					 combiner_handle_irq, combiner);

 	dev_info(&pdev->dev, "Initialized with [p=%d,n=%d,r=%p]\n",
 		 combiner->parent_irq, combiner->nirqs, combiner->regs[0].addr);
 	return 0;
 }

 static const struct acpi_device_id qcom_irq_combiner_ids[] = {
 	{ "QCOM80B1", },
 	{ }
 };

 static struct platform_driver qcom_irq_combiner_probe = {
 	.driver = {
 		.name = "qcom-irq-combiner",
 		.acpi_match_table = ACPI_PTR(qcom_irq_combiner_ids),
 	},
 	.probe = combiner_probe,
 };
 builtin_platform_driver(qcom_irq_combiner_probe);
	/* Copyright (c) 2015-2018, The Linux Foundation. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 and
	* only version 2 as published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*/

	/*
	* Driver for interrupt combiners in the Top-level Control and Status
	* Registers (TCSR) hardware block in Qualcomm Technologies chips.
	* An interrupt combiner in this block combines a set of interrupts by
	* OR'ing the individual interrupt signals into a summary interrupt
	* signal routed to a parent interrupt controller, and provides read-
	* only, 32-bit registers to query the status of individual interrupts.
	* The status bit for IRQ n is bit (n % 32) within register (n / 32)
	* of the given combiner. Thus, each combiner can be described as a set
	* of register offsets and the number of IRQs managed.
	*/

	#define pr_fmt(fmt) "QCOM80B1:" fmt

	#include <linux/acpi.h>
	#include <linux/irqchip/chained_irq.h>
	#include <linux/irqdomain.h>
	#include <linux/platform_device.h>

	#define REG_SIZE 32

	struct combiner_reg {
	void __iomem *addr;
	unsigned long enabled;
	};

	struct combiner {
	struct irq_domain *domain;
	int parent_irq;
	u32 nirqs;
	u32 nregs;
	struct combiner_reg regs[0];
	};

	static inline int irq_nr(u32 reg, u32 bit)
	{
	return reg * REG_SIZE + bit;
	}

	/*
	* Handler for the cascaded IRQ.
	*/
	static void combiner_handle_irq(struct irq_desc *desc)
	{
	struct combiner *combiner = irq_desc_get_handler_data(desc);
	struct irq_chip *chip = irq_desc_get_chip(desc);
	u32 reg;

	chained_irq_enter(chip, desc);

	for (reg = 0; reg < combiner->nregs; reg++) {
	int virq;
	int hwirq;
	u32 bit;
	u32 status;

	bit = readl_relaxed(combiner->regs[reg].addr);
	status = bit & combiner->regs[reg].enabled;
	if (bit && !status)
	pr_warn_ratelimited("Unexpected IRQ on CPU%d: (%08x %08lx %p)\n",
	smp_processor_id(), bit,
	combiner->regs[reg].enabled,
	combiner->regs[reg].addr);

	while (status) {
	bit = __ffs(status);
	status &= ~(1 << bit);
	hwirq = irq_nr(reg, bit);
	virq = irq_find_mapping(combiner->domain, hwirq);
	if (virq > 0)
	generic_handle_irq(virq);

	}
	}

	chained_irq_exit(chip, desc);
	}

	static void combiner_irq_chip_mask_irq(struct irq_data *data)
	{
	struct combiner *combiner = irq_data_get_irq_chip_data(data);
	struct combiner_reg *reg = combiner->regs + data->hwirq / REG_SIZE;

	clear_bit(data->hwirq % REG_SIZE, &reg->enabled);
	}

	static void combiner_irq_chip_unmask_irq(struct irq_data *data)
	{
	struct combiner *combiner = irq_data_get_irq_chip_data(data);
	struct combiner_reg *reg = combiner->regs + data->hwirq / REG_SIZE;

	set_bit(data->hwirq % REG_SIZE, &reg->enabled);
	}

	static struct irq_chip irq_chip = {
	.irq_mask = combiner_irq_chip_mask_irq,
	.irq_unmask = combiner_irq_chip_unmask_irq,
	.name = "qcom-irq-combiner"
	};

	static int combiner_irq_map(struct irq_domain *domain, unsigned int irq,
	irq_hw_number_t hwirq)
	{
	irq_set_chip_and_handler(irq, &irq_chip, handle_level_irq);
	irq_set_chip_data(irq, domain->host_data);
	irq_set_noprobe(irq);
	return 0;
	}

	static void combiner_irq_unmap(struct irq_domain *domain, unsigned int irq)
	{
	irq_domain_reset_irq_data(irq_get_irq_data(irq));
	}

	static int combiner_irq_translate(struct irq_domain d, struct irq_fwspec fws,
	unsigned long hwirq, unsigned int type)
	{
	struct combiner *combiner = d->host_data;

	if (is_acpi_node(fws->fwnode)) {
	if (WARN_ON((fws->param_count != 2) \|\|
	(fws->param[0] >= combiner->nirqs) \|\|
	(fws->param[1] & IORESOURCE_IRQ_LOWEDGE) \|\|
	(fws->param[1] & IORESOURCE_IRQ_HIGHEDGE)))
	return -EINVAL;

	*hwirq = fws->param[0];
	*type = fws->param[1];
	return 0;
	}

	return -EINVAL;
	}

	static const struct irq_domain_ops domain_ops = {
	.map = combiner_irq_map,
	.unmap = combiner_irq_unmap,
	.translate = combiner_irq_translate
	};

	static acpi_status count_registers_cb(struct acpi_resource ares, void context)
	{
	int *count = context;

	if (ares->type == ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
	++(*count);
	return AE_OK;
	}

	static int count_registers(struct platform_device *pdev)
	{
	acpi_handle ahandle = ACPI_HANDLE(&pdev->dev);
	acpi_status status;
	int count = 0;

	if (!acpi_has_method(ahandle, METHOD_NAME__CRS))
	return -EINVAL;

	status = acpi_walk_resources(ahandle, METHOD_NAME__CRS,
	count_registers_cb, &count);
	if (ACPI_FAILURE(status))
	return -EINVAL;
	return count;
	}

	struct get_registers_context {
	struct device *dev;
	struct combiner *combiner;
	int err;
	};

	static acpi_status get_registers_cb(struct acpi_resource ares, void context)
	{
	struct get_registers_context *ctx = context;
	struct acpi_resource_generic_register *reg;
	phys_addr_t paddr;
	void __iomem *vaddr;

	if (ares->type != ACPI_RESOURCE_TYPE_GENERIC_REGISTER)
	return AE_OK;

	reg = &ares->data.generic_reg;
	paddr = reg->address;
	if ((reg->space_id != ACPI_SPACE_MEM) \|\|
	(reg->bit_offset != 0) \|\|
	(reg->bit_width > REG_SIZE)) {
	dev_err(ctx->dev, "Bad register resource @%pa\n", &paddr);
	ctx->err = -EINVAL;
	return AE_ERROR;
	}

	vaddr = devm_ioremap(ctx->dev, reg->address, REG_SIZE);
	if (!vaddr) {
	dev_err(ctx->dev, "Can't map register @%pa\n", &paddr);
	ctx->err = -ENOMEM;
	return AE_ERROR;
	}

	ctx->combiner->regs[ctx->combiner->nregs].addr = vaddr;
	ctx->combiner->nirqs += reg->bit_width;
	ctx->combiner->nregs++;
	return AE_OK;
	}

	static int get_registers(struct platform_device pdev, struct combiner comb)
	{
	acpi_handle ahandle = ACPI_HANDLE(&pdev->dev);
	acpi_status status;
	struct get_registers_context ctx;

	if (!acpi_has_method(ahandle, METHOD_NAME__CRS))
	return -EINVAL;

	ctx.dev = &pdev->dev;
	ctx.combiner = comb;
	ctx.err = 0;

	status = acpi_walk_resources(ahandle, METHOD_NAME__CRS,
	get_registers_cb, &ctx);
	if (ACPI_FAILURE(status))
	return ctx.err;
	return 0;
	}

	static int __init combiner_probe(struct platform_device *pdev)
	{
	struct combiner *combiner;
	size_t alloc_sz;
	int nregs;
	int err;

	nregs = count_registers(pdev);
	if (nregs <= 0) {
	dev_err(&pdev->dev, "Error reading register resources\n");
	return -EINVAL;
	}

	alloc_sz = sizeof(combiner) + sizeof(struct combiner_reg) nregs;
	combiner = devm_kzalloc(&pdev->dev, alloc_sz, GFP_KERNEL);
	if (!combiner)
	return -ENOMEM;

	err = get_registers(pdev, combiner);
	if (err < 0)
	return err;

	combiner->parent_irq = platform_get_irq(pdev, 0);
	if (combiner->parent_irq <= 0) {
	dev_err(&pdev->dev, "Error getting IRQ resource\n");
	return -EPROBE_DEFER;
	}

	combiner->domain = irq_domain_create_linear(pdev->dev.fwnode, combiner->nirqs,
	&domain_ops, combiner);
	if (!combiner->domain)
	/* Errors printed by irq_domain_create_linear */
	return -ENODEV;

	irq_set_chained_handler_and_data(combiner->parent_irq,
	combiner_handle_irq, combiner);

	dev_info(&pdev->dev, "Initialized with [p=%d,n=%d,r=%p]\n",
	combiner->parent_irq, combiner->nirqs, combiner->regs[0].addr);
	return 0;
	}

	static const struct acpi_device_id qcom_irq_combiner_ids[] = {
	{ "QCOM80B1", },
	{ }
	};

	static struct platform_driver qcom_irq_combiner_probe = {
	.driver = {
	.name = "qcom-irq-combiner",
	.acpi_match_table = ACPI_PTR(qcom_irq_combiner_ids),
	},
	.probe = combiner_probe,
	};
	builtin_platform_driver(qcom_irq_combiner_probe);