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