diff options
Diffstat (limited to 'drivers/irqchip/irq-ts4800.c')
| -rw-r--r-- | drivers/irqchip/irq-ts4800.c | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/drivers/irqchip/irq-ts4800.c b/drivers/irqchip/irq-ts4800.c new file mode 100644 index 000000000..4192bdcd2 --- /dev/null +++ b/drivers/irqchip/irq-ts4800.c @@ -0,0 +1,163 @@ +/* + * 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; +} + +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"); |