// SPDX-License-Identifier: GPL-2.0-only /* * Aspeed 24XX/25XX I2C Interrupt Controller. * * Copyright (C) 2012-2017 ASPEED Technology Inc. * Copyright 2017 IBM Corporation * Copyright 2017 Google, Inc. */ #include <linux/irq.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/io.h> #define ASPEED_I2C_IC_NUM_BUS 14 struct aspeed_i2c_ic { void __iomem *base; int parent_irq; struct irq_domain *irq_domain; }; /* * The aspeed chip provides a single hardware interrupt for all of the I2C * busses, so we use a dummy interrupt chip to translate this single interrupt * into multiple interrupts, each associated with a single I2C bus. */ static void aspeed_i2c_ic_irq_handler(struct irq_desc *desc) { struct aspeed_i2c_ic *i2c_ic = irq_desc_get_handler_data(desc); struct irq_chip *chip = irq_desc_get_chip(desc); unsigned long bit, status; unsigned int bus_irq; chained_irq_enter(chip, desc); status = readl(i2c_ic->base); for_each_set_bit(bit, &status, ASPEED_I2C_IC_NUM_BUS) { bus_irq = irq_find_mapping(i2c_ic->irq_domain, bit); generic_handle_irq(bus_irq); } chained_irq_exit(chip, desc); } /* * Set simple handler and mark IRQ as valid. Nothing interesting to do here * since we are using a dummy interrupt chip. */ static int aspeed_i2c_ic_map_irq_domain(struct irq_domain *domain, unsigned int irq, irq_hw_number_t hwirq) { irq_set_chip_and_handler(irq, &dummy_irq_chip, handle_simple_irq); irq_set_chip_data(irq, domain->host_data); return 0; } static const struct irq_domain_ops aspeed_i2c_ic_irq_domain_ops = { .map = aspeed_i2c_ic_map_irq_domain, }; static int __init aspeed_i2c_ic_of_init(struct device_node *node, struct device_node *parent) { struct aspeed_i2c_ic *i2c_ic; int ret = 0; i2c_ic = kzalloc(sizeof(*i2c_ic), GFP_KERNEL); if (!i2c_ic) return -ENOMEM; i2c_ic->base = of_iomap(node, 0); if (!i2c_ic->base) { ret = -ENOMEM; goto err_free_ic; } i2c_ic->parent_irq = irq_of_parse_and_map(node, 0); if (i2c_ic->parent_irq < 0) { ret = i2c_ic->parent_irq; goto err_iounmap; } i2c_ic->irq_domain = irq_domain_add_linear(node, ASPEED_I2C_IC_NUM_BUS, &aspeed_i2c_ic_irq_domain_ops, NULL); if (!i2c_ic->irq_domain) { ret = -ENOMEM; goto err_iounmap; } i2c_ic->irq_domain->name = "aspeed-i2c-domain"; irq_set_chained_handler_and_data(i2c_ic->parent_irq, aspeed_i2c_ic_irq_handler, i2c_ic); pr_info("i2c controller registered, irq %d\n", i2c_ic->parent_irq); return 0; err_iounmap: iounmap(i2c_ic->base); err_free_ic: kfree(i2c_ic); return ret; } IRQCHIP_DECLARE(ast2400_i2c_ic, "aspeed,ast2400-i2c-ic", aspeed_i2c_ic_of_init); IRQCHIP_DECLARE(ast2500_i2c_ic, "aspeed,ast2500-i2c-ic", aspeed_i2c_ic_of_init);