/* * Multiplexed-IRQs driver for TS-4800's FPGA * * Copyright (c) 2015 - Savoir-faire Linux * * This file is licensed under the terms of the GNU General Public * License version 2. This program is licensed "as is" without any * warranty of any kind, whether express or implied. */ #include <linux/interrupt.h> #include <linux/io.h> #include <linux/irq.h> #include <linux/irqchip.h> #include <linux/irqchip/chained_irq.h> #include <linux/irqdomain.h> #include <linux/module.h> #include <linux/of.h> #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/platform_device.h> #define IRQ_MASK 0x4 #define IRQ_STATUS 0x8 struct ts4800_irq_data { void __iomem *base; struct irq_domain *domain; struct irq_chip irq_chip; }; static void ts4800_irq_mask(struct irq_data *d) { struct ts4800_irq_data *data = irq_data_get_irq_chip_data(d); u16 reg = readw(data->base + IRQ_MASK); u16 mask = 1 << d->hwirq; writew(reg | mask, data->base + IRQ_MASK); } static void ts4800_irq_unmask(struct irq_data *d) { struct ts4800_irq_data *data = irq_data_get_irq_chip_data(d); u16 reg = readw(data->base + IRQ_MASK); u16 mask = 1 << d->hwirq; writew(reg & ~mask, data->base + IRQ_MASK); } static int ts4800_irqdomain_map(struct irq_domain *d, unsigned int irq, irq_hw_number_t hwirq) { struct ts4800_irq_data *data = d->host_data; irq_set_chip_and_handler(irq, &data->irq_chip, handle_simple_irq); irq_set_chip_data(irq, data); irq_set_noprobe(irq); return 0; } static const struct irq_domain_ops ts4800_ic_ops = { .map = ts4800_irqdomain_map, .xlate = irq_domain_xlate_onecell, }; static void ts4800_ic_chained_handle_irq(struct irq_desc *desc) { struct ts4800_irq_data *data = irq_desc_get_handler_data(desc); struct irq_chip *chip = irq_desc_get_chip(desc); u16 status = readw(data->base + IRQ_STATUS); chained_irq_enter(chip, desc); if (unlikely(status == 0)) { handle_bad_irq(desc); goto out; } do { unsigned int bit = __ffs(status); int irq = irq_find_mapping(data->domain, bit); status &= ~(1 << bit); generic_handle_irq(irq); } while (status); out: chained_irq_exit(chip, desc); } static int ts4800_ic_probe(struct platform_device *pdev) { struct device_node *node = pdev->dev.of_node; struct ts4800_irq_data *data; struct irq_chip *irq_chip; struct resource *res; int parent_irq; data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); if (!data) return -ENOMEM; res = platform_get_resource(pdev, IORESOURCE_MEM, 0); data->base = devm_ioremap_resource(&pdev->dev, res); if (IS_ERR(data->base)) return PTR_ERR(data->base); writew(0xFFFF, data->base + IRQ_MASK); parent_irq = irq_of_parse_and_map(node, 0); if (!parent_irq) { dev_err(&pdev->dev, "failed to get parent IRQ\n"); return -EINVAL; } irq_chip = &data->irq_chip; irq_chip->name = dev_name(&pdev->dev); irq_chip->irq_mask = ts4800_irq_mask; irq_chip->irq_unmask = ts4800_irq_unmask; data->domain = irq_domain_add_linear(node, 8, &ts4800_ic_ops, data); if (!data->domain) { dev_err(&pdev->dev, "cannot add IRQ domain\n"); return -ENOMEM; } irq_set_chained_handler_and_data(parent_irq, ts4800_ic_chained_handle_irq, data); platform_set_drvdata(pdev, data); return 0; } static int ts4800_ic_remove(struct platform_device *pdev) { struct ts4800_irq_data *data = platform_get_drvdata(pdev); irq_domain_remove(data->domain); return 0; } static const struct of_device_id ts4800_ic_of_match[] = { { .compatible = "technologic,ts4800-irqc", }, {}, }; MODULE_DEVICE_TABLE(of, ts4800_ic_of_match); static struct platform_driver ts4800_ic_driver = { .probe = ts4800_ic_probe, .remove = ts4800_ic_remove, .driver = { .name = "ts4800-irqc", .of_match_table = ts4800_ic_of_match, }, }; module_platform_driver(ts4800_ic_driver); MODULE_AUTHOR("Damien Riegel <damien.riegel@savoirfairelinux.com>"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:ts4800_irqc");