drivers/ssb/driver_gpio.c

   1 /*
   2  * Sonics Silicon Backplane
   3  * GPIO driver
   4  *
   5  * Copyright 2011, Broadcom Corporation
   6  * Copyright 2012, Hauke Mehrtens <hauke@hauke-m.de>
   7  *
   8  * Licensed under the GNU/GPL. See COPYING for details.
   9  */
  10
  11 #include <linux/gpio.h>
  12 #include <linux/export.h>
  13 #include <linux/ssb/ssb.h>
  14
  15 #include "ssb_private.h"
  16
  17 static struct ssb_bus *ssb_gpio_get_bus(struct gpio_chip *chip)
  18 {
  19         return container_of(chip, struct ssb_bus, gpio);
  20 }
  21
  22 static int ssb_gpio_chipco_get_value(struct gpio_chip *chip, unsigned gpio)
  23 {
  24         struct ssb_bus *bus = ssb_gpio_get_bus(chip);
  25
  26         return !!ssb_chipco_gpio_in(&bus->chipco, 1 << gpio);
  27 }
  28
  29 static void ssb_gpio_chipco_set_value(struct gpio_chip *chip, unsigned gpio,
  30                                       int value)
  31 {
  32         struct ssb_bus *bus = ssb_gpio_get_bus(chip);
  33
  34         ssb_chipco_gpio_out(&bus->chipco, 1 << gpio, value ? 1 << gpio : 0);
  35 }
  36
  37 static int ssb_gpio_chipco_direction_input(struct gpio_chip *chip,
  38                                            unsigned gpio)
  39 {
  40         struct ssb_bus *bus = ssb_gpio_get_bus(chip);
  41
  42         ssb_chipco_gpio_outen(&bus->chipco, 1 << gpio, 0);
  43         return 0;
  44 }
  45
  46 static int ssb_gpio_chipco_direction_output(struct gpio_chip *chip,
  47                                             unsigned gpio, int value)
  48 {
  49         struct ssb_bus *bus = ssb_gpio_get_bus(chip);
  50
  51         ssb_chipco_gpio_outen(&bus->chipco, 1 << gpio, 1 << gpio);
  52         ssb_chipco_gpio_out(&bus->chipco, 1 << gpio, value ? 1 << gpio : 0);
  53         return 0;
  54 }
  55
  56 static int ssb_gpio_chipco_request(struct gpio_chip *chip, unsigned gpio)
  57 {
  58         struct ssb_bus *bus = ssb_gpio_get_bus(chip);
  59
  60         ssb_chipco_gpio_control(&bus->chipco, 1 << gpio, 0);
  61         /* clear pulldown */
  62         ssb_chipco_gpio_pulldown(&bus->chipco, 1 << gpio, 0);
  63         /* Set pullup */
  64         ssb_chipco_gpio_pullup(&bus->chipco, 1 << gpio, 1 << gpio);
  65
  66         return 0;
  67 }
  68
  69 static void ssb_gpio_chipco_free(struct gpio_chip *chip, unsigned gpio)
  70 {
  71         struct ssb_bus *bus = ssb_gpio_get_bus(chip);
  72
  73         /* clear pullup */
  74         ssb_chipco_gpio_pullup(&bus->chipco, 1 << gpio, 0);
  75 }
  76
  77 static int ssb_gpio_chipco_init(struct ssb_bus *bus)
  78 {
  79         struct gpio_chip *chip = &bus->gpio;
  80
  81         chip->label             = "ssb_chipco_gpio";
  82         chip->owner             = THIS_MODULE;
  83         chip->request           = ssb_gpio_chipco_request;
  84         chip->free              = ssb_gpio_chipco_free;
  85         chip->get               = ssb_gpio_chipco_get_value;
  86         chip->set               = ssb_gpio_chipco_set_value;
  87         chip->direction_input   = ssb_gpio_chipco_direction_input;
  88         chip->direction_output  = ssb_gpio_chipco_direction_output;
  89         chip->ngpio             = 16;
  90         /* There is just one SoC in one device and its GPIO addresses should be
  91          * deterministic to address them more easily. The other buses could get
  92          * a random base number. */
  93         if (bus->bustype == SSB_BUSTYPE_SSB)
  94                 chip->base              = 0;
  95         else
  96                 chip->base              = -1;
  97
  98         return gpiochip_add(chip);
  99 }
 100
 101 #ifdef CONFIG_SSB_DRIVER_EXTIF
 102
 103 static int ssb_gpio_extif_get_value(struct gpio_chip *chip, unsigned gpio)
 104 {
 105         struct ssb_bus *bus = ssb_gpio_get_bus(chip);
 106
 107         return !!ssb_extif_gpio_in(&bus->extif, 1 << gpio);
 108 }
 109
 110 static void ssb_gpio_extif_set_value(struct gpio_chip *chip, unsigned gpio,
 111                                      int value)
 112 {
 113         struct ssb_bus *bus = ssb_gpio_get_bus(chip);
 114
 115         ssb_extif_gpio_out(&bus->extif, 1 << gpio, value ? 1 << gpio : 0);
 116 }
 117
 118 static int ssb_gpio_extif_direction_input(struct gpio_chip *chip,
 119                                           unsigned gpio)
 120 {
 121         struct ssb_bus *bus = ssb_gpio_get_bus(chip);
 122
 123         ssb_extif_gpio_outen(&bus->extif, 1 << gpio, 0);
 124         return 0;
 125 }
 126
 127 static int ssb_gpio_extif_direction_output(struct gpio_chip *chip,
 128                                            unsigned gpio, int value)
 129 {
 130         struct ssb_bus *bus = ssb_gpio_get_bus(chip);
 131
 132         ssb_extif_gpio_outen(&bus->extif, 1 << gpio, 1 << gpio);
 133         ssb_extif_gpio_out(&bus->extif, 1 << gpio, value ? 1 << gpio : 0);
 134         return 0;
 135 }
 136
 137 static int ssb_gpio_extif_init(struct ssb_bus *bus)
 138 {
 139         struct gpio_chip *chip = &bus->gpio;
 140
 141         chip->label             = "ssb_extif_gpio";
 142         chip->owner             = THIS_MODULE;
 143         chip->get               = ssb_gpio_extif_get_value;
 144         chip->set               = ssb_gpio_extif_set_value;
 145         chip->direction_input   = ssb_gpio_extif_direction_input;
 146         chip->direction_output  = ssb_gpio_extif_direction_output;
 147         chip->ngpio             = 5;
 148         /* There is just one SoC in one device and its GPIO addresses should be
 149          * deterministic to address them more easily. The other buses could get
 150          * a random base number. */
 151         if (bus->bustype == SSB_BUSTYPE_SSB)
 152                 chip->base              = 0;
 153         else
 154                 chip->base              = -1;
 155
 156         return gpiochip_add(chip);
 157 }
 158
 159 #else
 160 static int ssb_gpio_extif_init(struct ssb_bus *bus)
 161 {
 162         return -ENOTSUPP;
 163 }
 164 #endif
 165
 166 int ssb_gpio_init(struct ssb_bus *bus)
 167 {
 168         if (ssb_chipco_available(&bus->chipco))
 169                 return ssb_gpio_chipco_init(bus);
 170         else if (ssb_extif_available(&bus->extif))
 171                 return ssb_gpio_extif_init(bus);
 172         else
 173                 SSB_WARN_ON(1);
 174
 175         return -1;
 176 }