arch/sh/boards/mach-x3proto/gpio.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * arch/sh/boards/mach-x3proto/gpio.c
   4  *
   5  * Renesas SH-X3 Prototype Baseboard GPIO Support.
   6  *
   7  * Copyright (C) 2010 - 2012  Paul Mundt
   8  */
   9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11 #include <linux/init.h>
  12 #include <linux/interrupt.h>
  13 #include <linux/gpio/driver.h>
  14 #include <linux/irq.h>
  15 #include <linux/kernel.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/irqdomain.h>
  18 #include <linux/io.h>
  19 #include <mach/ilsel.h>
  20 #include <mach/hardware.h>
  21
  22 #define KEYCTLR 0xb81c0000
  23 #define KEYOUTR 0xb81c0002
  24 #define KEYDETR 0xb81c0004
  25
  26 static DEFINE_SPINLOCK(x3proto_gpio_lock);
  27 static struct irq_domain *x3proto_irq_domain;
  28
  29 static int x3proto_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
  30 {
  31         unsigned long flags;
  32         unsigned int data;
  33
  34         spin_lock_irqsave(&x3proto_gpio_lock, flags);
  35         data = __raw_readw(KEYCTLR);
  36         data |= (1 << gpio);
  37         __raw_writew(data, KEYCTLR);
  38         spin_unlock_irqrestore(&x3proto_gpio_lock, flags);
  39
  40         return 0;
  41 }
  42
  43 static int x3proto_gpio_get(struct gpio_chip *chip, unsigned gpio)
  44 {
  45         return !!(__raw_readw(KEYDETR) & (1 << gpio));
  46 }
  47
  48 static int x3proto_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
  49 {
  50         int virq;
  51
  52         if (gpio < chip->ngpio)
  53                 virq = irq_create_mapping(x3proto_irq_domain, gpio);
  54         else
  55                 virq = -ENXIO;
  56
  57         return virq;
  58 }
  59
  60 static void x3proto_gpio_irq_handler(struct irq_desc *desc)
  61 {
  62         struct irq_data *data = irq_desc_get_irq_data(desc);
  63         struct irq_chip *chip = irq_data_get_irq_chip(data);
  64         unsigned long mask;
  65         int pin;
  66
  67         chip->irq_mask_ack(data);
  68
  69         mask = __raw_readw(KEYDETR);
  70         for_each_set_bit(pin, &mask, NR_BASEBOARD_GPIOS)
  71                 generic_handle_irq(irq_linear_revmap(x3proto_irq_domain, pin));
  72
  73         chip->irq_unmask(data);
  74 }
  75
  76 struct gpio_chip x3proto_gpio_chip = {
  77         .label                  = "x3proto-gpio",
  78         .direction_input        = x3proto_gpio_direction_input,
  79         .get                    = x3proto_gpio_get,
  80         .to_irq                 = x3proto_gpio_to_irq,
  81         .base                   = -1,
  82         .ngpio                  = NR_BASEBOARD_GPIOS,
  83 };
  84
  85 static int x3proto_gpio_irq_map(struct irq_domain *domain, unsigned int virq,
  86                                 irq_hw_number_t hwirq)
  87 {
  88         irq_set_chip_and_handler_name(virq, &dummy_irq_chip, handle_simple_irq,
  89                                       "gpio");
  90
  91         return 0;
  92 }
  93
  94 static struct irq_domain_ops x3proto_gpio_irq_ops = {
  95         .map    = x3proto_gpio_irq_map,
  96         .xlate  = irq_domain_xlate_twocell,
  97 };
  98
  99 int __init x3proto_gpio_setup(void)
 100 {
 101         int ilsel, ret;
 102
 103         ilsel = ilsel_enable(ILSEL_KEY);
 104         if (unlikely(ilsel < 0))
 105                 return ilsel;
 106
 107         ret = gpiochip_add_data(&x3proto_gpio_chip, NULL);
 108         if (unlikely(ret))
 109                 goto err_gpio;
 110
 111         x3proto_irq_domain = irq_domain_add_linear(NULL, NR_BASEBOARD_GPIOS,
 112                                                    &x3proto_gpio_irq_ops, NULL);
 113         if (unlikely(!x3proto_irq_domain))
 114                 goto err_irq;
 115
 116         pr_info("registering '%s' support, handling GPIOs %u -> %u, "
 117                 "bound to IRQ %u\n",
 118                 x3proto_gpio_chip.label, x3proto_gpio_chip.base,
 119                 x3proto_gpio_chip.base + x3proto_gpio_chip.ngpio,
 120                 ilsel);
 121
 122         irq_set_chained_handler(ilsel, x3proto_gpio_irq_handler);
 123         irq_set_irq_wake(ilsel, 1);
 124
 125         return 0;
 126
 127 err_irq:
 128         gpiochip_remove(&x3proto_gpio_chip);
 129         ret = 0;
 130 err_gpio:
 131         synchronize_irq(ilsel);
 132
 133         ilsel_disable(ILSEL_KEY);
 134
 135         return ret;
 136 }