arch/mips/lantiq/xway/gpio.c

   1 /*
   2  *  This program is free software; you can redistribute it and/or modify it
   3  *  under the terms of the GNU General Public License version 2 as published
   4  *  by the Free Software Foundation.
   5  *
   6  *  Copyright (C) 2010 John Crispin <blogic@openwrt.org>
   7  */
   8
   9 #include <linux/slab.h>
  10 #include <linux/export.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/gpio.h>
  13 #include <linux/ioport.h>
  14 #include <linux/io.h>
  15
  16 #include <lantiq_soc.h>
  17
  18 #define LTQ_GPIO_OUT            0x00
  19 #define LTQ_GPIO_IN             0x04
  20 #define LTQ_GPIO_DIR            0x08
  21 #define LTQ_GPIO_ALTSEL0        0x0C
  22 #define LTQ_GPIO_ALTSEL1        0x10
  23 #define LTQ_GPIO_OD             0x14
  24
  25 #define PINS_PER_PORT           16
  26 #define MAX_PORTS               3
  27
  28 #define ltq_gpio_getbit(m, r, p)        (!!(ltq_r32(m + r) & (1 << p)))
  29 #define ltq_gpio_setbit(m, r, p)        ltq_w32_mask(0, (1 << p), m + r)
  30 #define ltq_gpio_clearbit(m, r, p)      ltq_w32_mask((1 << p), 0, m + r)
  31
  32 struct ltq_gpio {
  33         void __iomem *membase;
  34         struct gpio_chip chip;
  35 };
  36
  37 static struct ltq_gpio ltq_gpio_port[MAX_PORTS];
  38
  39 int gpio_to_irq(unsigned int gpio)
  40 {
  41         return -EINVAL;
  42 }
  43 EXPORT_SYMBOL(gpio_to_irq);
  44
  45 int irq_to_gpio(unsigned int gpio)
  46 {
  47         return -EINVAL;
  48 }
  49 EXPORT_SYMBOL(irq_to_gpio);
  50
  51 int ltq_gpio_request(unsigned int pin, unsigned int alt0,
  52         unsigned int alt1, unsigned int dir, const char *name)
  53 {
  54         int id = 0;
  55
  56         if (pin >= (MAX_PORTS * PINS_PER_PORT))
  57                 return -EINVAL;
  58         if (gpio_request(pin, name)) {
  59                 pr_err("failed to setup lantiq gpio: %s\n", name);
  60                 return -EBUSY;
  61         }
  62         if (dir)
  63                 gpio_direction_output(pin, 1);
  64         else
  65                 gpio_direction_input(pin);
  66         while (pin >= PINS_PER_PORT) {
  67                 pin -= PINS_PER_PORT;
  68                 id++;
  69         }
  70         if (alt0)
  71                 ltq_gpio_setbit(ltq_gpio_port[id].membase,
  72                         LTQ_GPIO_ALTSEL0, pin);
  73         else
  74                 ltq_gpio_clearbit(ltq_gpio_port[id].membase,
  75                         LTQ_GPIO_ALTSEL0, pin);
  76         if (alt1)
  77                 ltq_gpio_setbit(ltq_gpio_port[id].membase,
  78                         LTQ_GPIO_ALTSEL1, pin);
  79         else
  80                 ltq_gpio_clearbit(ltq_gpio_port[id].membase,
  81                         LTQ_GPIO_ALTSEL1, pin);
  82         return 0;
  83 }
  84 EXPORT_SYMBOL(ltq_gpio_request);
  85
  86 static void ltq_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
  87 {
  88         struct ltq_gpio *ltq_gpio = container_of(chip, struct ltq_gpio, chip);
  89
  90         if (value)
  91                 ltq_gpio_setbit(ltq_gpio->membase, LTQ_GPIO_OUT, offset);
  92         else
  93                 ltq_gpio_clearbit(ltq_gpio->membase, LTQ_GPIO_OUT, offset);
  94 }
  95
  96 static int ltq_gpio_get(struct gpio_chip *chip, unsigned int offset)
  97 {
  98         struct ltq_gpio *ltq_gpio = container_of(chip, struct ltq_gpio, chip);
  99
 100         return ltq_gpio_getbit(ltq_gpio->membase, LTQ_GPIO_IN, offset);
 101 }
 102
 103 static int ltq_gpio_direction_input(struct gpio_chip *chip, unsigned int offset)
 104 {
 105         struct ltq_gpio *ltq_gpio = container_of(chip, struct ltq_gpio, chip);
 106
 107         ltq_gpio_clearbit(ltq_gpio->membase, LTQ_GPIO_OD, offset);
 108         ltq_gpio_clearbit(ltq_gpio->membase, LTQ_GPIO_DIR, offset);
 109
 110         return 0;
 111 }
 112
 113 static int ltq_gpio_direction_output(struct gpio_chip *chip,
 114         unsigned int offset, int value)
 115 {
 116         struct ltq_gpio *ltq_gpio = container_of(chip, struct ltq_gpio, chip);
 117
 118         ltq_gpio_setbit(ltq_gpio->membase, LTQ_GPIO_OD, offset);
 119         ltq_gpio_setbit(ltq_gpio->membase, LTQ_GPIO_DIR, offset);
 120         ltq_gpio_set(chip, offset, value);
 121
 122         return 0;
 123 }
 124
 125 static int ltq_gpio_req(struct gpio_chip *chip, unsigned offset)
 126 {
 127         struct ltq_gpio *ltq_gpio = container_of(chip, struct ltq_gpio, chip);
 128
 129         ltq_gpio_clearbit(ltq_gpio->membase, LTQ_GPIO_ALTSEL0, offset);
 130         ltq_gpio_clearbit(ltq_gpio->membase, LTQ_GPIO_ALTSEL1, offset);
 131         return 0;
 132 }
 133
 134 static int ltq_gpio_probe(struct platform_device *pdev)
 135 {
 136         struct resource *res;
 137
 138         if (pdev->id >= MAX_PORTS) {
 139                 dev_err(&pdev->dev, "invalid gpio port %d\n",
 140                         pdev->id);
 141                 return -EINVAL;
 142         }
 143         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 144         if (!res) {
 145                 dev_err(&pdev->dev, "failed to get memory for gpio port %d\n",
 146                         pdev->id);
 147                 return -ENOENT;
 148         }
 149         res = devm_request_mem_region(&pdev->dev, res->start,
 150                 resource_size(res), dev_name(&pdev->dev));
 151         if (!res) {
 152                 dev_err(&pdev->dev,
 153                         "failed to request memory for gpio port %d\n",
 154                         pdev->id);
 155                 return -EBUSY;
 156         }
 157         ltq_gpio_port[pdev->id].membase = devm_ioremap_nocache(&pdev->dev,
 158                 res->start, resource_size(res));
 159         if (!ltq_gpio_port[pdev->id].membase) {
 160                 dev_err(&pdev->dev, "failed to remap memory for gpio port %d\n",
 161                         pdev->id);
 162                 return -ENOMEM;
 163         }
 164         ltq_gpio_port[pdev->id].chip.label = "ltq_gpio";
 165         ltq_gpio_port[pdev->id].chip.direction_input = ltq_gpio_direction_input;
 166         ltq_gpio_port[pdev->id].chip.direction_output =
 167                 ltq_gpio_direction_output;
 168         ltq_gpio_port[pdev->id].chip.get = ltq_gpio_get;
 169         ltq_gpio_port[pdev->id].chip.set = ltq_gpio_set;
 170         ltq_gpio_port[pdev->id].chip.request = ltq_gpio_req;
 171         ltq_gpio_port[pdev->id].chip.base = PINS_PER_PORT * pdev->id;
 172         ltq_gpio_port[pdev->id].chip.ngpio = PINS_PER_PORT;
 173         platform_set_drvdata(pdev, &ltq_gpio_port[pdev->id]);
 174         return gpiochip_add(&ltq_gpio_port[pdev->id].chip);
 175 }
 176
 177 static struct platform_driver
 178 ltq_gpio_driver = {
 179         .probe = ltq_gpio_probe,
 180         .driver = {
 181                 .name = "ltq_gpio",
 182                 .owner = THIS_MODULE,
 183         },
 184 };
 185
 186 int __init ltq_gpio_init(void)
 187 {
 188         int ret = platform_driver_register(&ltq_gpio_driver);
 189
 190         if (ret)
 191                 pr_info("ltq_gpio : Error registering platfom driver!");
 192         return ret;
 193 }
 194
 195 postcore_initcall(ltq_gpio_init);