diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/irqchip/Makefile | 2 | ||||
| -rw-r--r-- | drivers/irqchip/irq-aspeed-i2c-ic.c | 115 |
2 files changed, 116 insertions, 1 deletions
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile index b64c59b838a0..e067f9839b33 100644 --- a/drivers/irqchip/Makefile +++ b/drivers/irqchip/Makefile @@ -73,6 +73,6 @@ obj-$(CONFIG_MVEBU_ODMI) += irq-mvebu-odmi.o obj-$(CONFIG_MVEBU_PIC) += irq-mvebu-pic.o obj-$(CONFIG_LS_SCFG_MSI) += irq-ls-scfg-msi.o obj-$(CONFIG_EZNPS_GIC) += irq-eznps.o -obj-$(CONFIG_ARCH_ASPEED) += irq-aspeed-vic.o +obj-$(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 diff --git a/drivers/irqchip/irq-aspeed-i2c-ic.c b/drivers/irqchip/irq-aspeed-i2c-ic.c new file mode 100644 index 000000000000..815b88dd18f2 --- /dev/null +++ b/drivers/irqchip/irq-aspeed-i2c-ic.c @@ -0,0 +1,115 @@ +/* + * Aspeed 24XX/25XX I2C Interrupt Controller. + * + * Copyright (C) 2012-2017 ASPEED Technology Inc. + * Copyright 2017 IBM Corporation + * Copyright 2017 Google, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#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 (IS_ERR(i2c_ic->base)) { + ret = PTR_ERR(i2c_ic->base); + 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); |