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163 lines
3.9 KiB
163 lines
3.9 KiB
/* |
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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 <[email protected]>"); |
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MODULE_LICENSE("GPL v2"); |
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MODULE_ALIAS("platform:ts4800_irqc");
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