arch/arm/mach-pxa/pxa_cplds_irqs.c

   1 /*
   2  * Intel Reference Systems cplds
   3  *
   4  * Copyright (C) 2014 Robert Jarzmik
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * Cplds motherboard driver, supporting lubbock and mainstone SoC board.
  12  */
  13
  14 #include <linux/bitops.h>
  15 #include <linux/gpio.h>
  16 #include <linux/gpio/consumer.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/io.h>
  19 #include <linux/irq.h>
  20 #include <linux/irqdomain.h>
  21 #include <linux/mfd/core.h>
  22 #include <linux/module.h>
  23 #include <linux/of_platform.h>
  24
  25 #define FPGA_IRQ_MASK_EN 0x0
  26 #define FPGA_IRQ_SET_CLR 0x10
  27
  28 #define CPLDS_NB_IRQ    32
  29
  30 struct cplds {
  31         void __iomem *base;
  32         int irq;
  33         unsigned int irq_mask;
  34         struct gpio_desc *gpio0;
  35         struct irq_domain *irqdomain;
  36 };
  37
  38 static irqreturn_t cplds_irq_handler(int in_irq, void *d)
  39 {
  40         struct cplds *fpga = d;
  41         unsigned long pending;
  42         unsigned int bit;
  43
  44         do {
  45                 pending = readl(fpga->base + FPGA_IRQ_SET_CLR) & fpga->irq_mask;
  46                 for_each_set_bit(bit, &pending, CPLDS_NB_IRQ) {
  47                         generic_handle_irq(irq_find_mapping(fpga->irqdomain,
  48                                                             bit));
  49                 }
  50         } while (pending);
  51
  52         return IRQ_HANDLED;
  53 }
  54
  55 static void cplds_irq_mask(struct irq_data *d)
  56 {
  57         struct cplds *fpga = irq_data_get_irq_chip_data(d);
  58         unsigned int cplds_irq = irqd_to_hwirq(d);
  59         unsigned int bit = BIT(cplds_irq);
  60
  61         fpga->irq_mask &= ~bit;
  62         writel(fpga->irq_mask, fpga->base + FPGA_IRQ_MASK_EN);
  63 }
  64
  65 static void cplds_irq_unmask(struct irq_data *d)
  66 {
  67         struct cplds *fpga = irq_data_get_irq_chip_data(d);
  68         unsigned int cplds_irq = irqd_to_hwirq(d);
  69         unsigned int set, bit = BIT(cplds_irq);
  70
  71         set = readl(fpga->base + FPGA_IRQ_SET_CLR);
  72         writel(set & ~bit, fpga->base + FPGA_IRQ_SET_CLR);
  73
  74         fpga->irq_mask |= bit;
  75         writel(fpga->irq_mask, fpga->base + FPGA_IRQ_MASK_EN);
  76 }
  77
  78 static struct irq_chip cplds_irq_chip = {
  79         .name           = "pxa_cplds",
  80         .irq_ack        = cplds_irq_mask,
  81         .irq_mask       = cplds_irq_mask,
  82         .irq_unmask     = cplds_irq_unmask,
  83         .flags          = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE,
  84 };
  85
  86 static int cplds_irq_domain_map(struct irq_domain *d, unsigned int irq,
  87                                    irq_hw_number_t hwirq)
  88 {
  89         struct cplds *fpga = d->host_data;
  90
  91         irq_set_chip_and_handler(irq, &cplds_irq_chip, handle_level_irq);
  92         irq_set_chip_data(irq, fpga);
  93
  94         return 0;
  95 }
  96
  97 static const struct irq_domain_ops cplds_irq_domain_ops = {
  98         .xlate = irq_domain_xlate_twocell,
  99         .map = cplds_irq_domain_map,
 100 };
 101
 102 static int cplds_resume(struct platform_device *pdev)
 103 {
 104         struct cplds *fpga = platform_get_drvdata(pdev);
 105
 106         writel(fpga->irq_mask, fpga->base + FPGA_IRQ_MASK_EN);
 107
 108         return 0;
 109 }
 110
 111 static int cplds_probe(struct platform_device *pdev)
 112 {
 113         struct resource *res;
 114         struct cplds *fpga;
 115         int ret;
 116         int base_irq;
 117         unsigned long irqflags = 0;
 118
 119         fpga = devm_kzalloc(&pdev->dev, sizeof(*fpga), GFP_KERNEL);
 120         if (!fpga)
 121                 return -ENOMEM;
 122
 123         res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
 124         if (res) {
 125                 fpga->irq = (unsigned int)res->start;
 126                 irqflags = res->flags;
 127         }
 128         if (!fpga->irq)
 129                 return -ENODEV;
 130
 131         base_irq = platform_get_irq(pdev, 1);
 132         if (base_irq < 0)
 133                 base_irq = 0;
 134
 135         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 136         fpga->base = devm_ioremap_resource(&pdev->dev, res);
 137         if (IS_ERR(fpga->base))
 138                 return PTR_ERR(fpga->base);
 139
 140         platform_set_drvdata(pdev, fpga);
 141
 142         writel(fpga->irq_mask, fpga->base + FPGA_IRQ_MASK_EN);
 143         writel(0, fpga->base + FPGA_IRQ_SET_CLR);
 144
 145         ret = devm_request_irq(&pdev->dev, fpga->irq, cplds_irq_handler,
 146                                irqflags, dev_name(&pdev->dev), fpga);
 147         if (ret == -ENOSYS)
 148                 return -EPROBE_DEFER;
 149
 150         if (ret) {
 151                 dev_err(&pdev->dev, "couldn't request main irq%d: %d\n",
 152                         fpga->irq, ret);
 153                 return ret;
 154         }
 155
 156         irq_set_irq_wake(fpga->irq, 1);
 157         fpga->irqdomain = irq_domain_add_linear(pdev->dev.of_node,
 158                                                CPLDS_NB_IRQ,
 159                                                &cplds_irq_domain_ops, fpga);
 160         if (!fpga->irqdomain)
 161                 return -ENODEV;
 162
 163         if (base_irq) {
 164                 ret = irq_create_strict_mappings(fpga->irqdomain, base_irq, 0,
 165                                                  CPLDS_NB_IRQ);
 166                 if (ret) {
 167                         dev_err(&pdev->dev, "couldn't create the irq mapping %d..%d\n",
 168                                 base_irq, base_irq + CPLDS_NB_IRQ);
 169                         return ret;
 170                 }
 171         }
 172
 173         return 0;
 174 }
 175
 176 static int cplds_remove(struct platform_device *pdev)
 177 {
 178         struct cplds *fpga = platform_get_drvdata(pdev);
 179
 180         irq_set_chip_and_handler(fpga->irq, NULL, NULL);
 181
 182         return 0;
 183 }
 184
 185 static const struct of_device_id cplds_id_table[] = {
 186         { .compatible = "intel,lubbock-cplds-irqs", },
 187         { .compatible = "intel,mainstone-cplds-irqs", },
 188         { }
 189 };
 190 MODULE_DEVICE_TABLE(of, cplds_id_table);
 191
 192 static struct platform_driver cplds_driver = {
 193         .driver         = {
 194                 .name   = "pxa_cplds_irqs",
 195                 .of_match_table = of_match_ptr(cplds_id_table),
 196         },
 197         .probe          = cplds_probe,
 198         .remove         = cplds_remove,
 199         .resume         = cplds_resume,
 200 };
 201
 202 module_platform_driver(cplds_driver);
 203
 204 MODULE_DESCRIPTION("PXA Cplds interrupts driver");
 205 MODULE_AUTHOR("Robert Jarzmik <robert.jarzmik@free.fr>");
 206 MODULE_LICENSE("GPL");