drivers/bcma/driver_gpio.c

   1 /*
   2  * Broadcom specific AMBA
   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/bcma/bcma.h>
  14
  15 #include "bcma_private.h"
  16
  17 static inline struct bcma_drv_cc *bcma_gpio_get_cc(struct gpio_chip *chip)
  18 {
  19         return container_of(chip, struct bcma_drv_cc, gpio);
  20 }
  21
  22 static int bcma_gpio_get_value(struct gpio_chip *chip, unsigned gpio)
  23 {
  24         struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
  25
  26         return !!bcma_chipco_gpio_in(cc, 1 << gpio);
  27 }
  28
  29 static void bcma_gpio_set_value(struct gpio_chip *chip, unsigned gpio,
  30                                 int value)
  31 {
  32         struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
  33
  34         bcma_chipco_gpio_out(cc, 1 << gpio, value ? 1 << gpio : 0);
  35 }
  36
  37 static int bcma_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
  38 {
  39         struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
  40
  41         bcma_chipco_gpio_outen(cc, 1 << gpio, 0);
  42         return 0;
  43 }
  44
  45 static int bcma_gpio_direction_output(struct gpio_chip *chip, unsigned gpio,
  46                                       int value)
  47 {
  48         struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
  49
  50         bcma_chipco_gpio_outen(cc, 1 << gpio, 1 << gpio);
  51         bcma_chipco_gpio_out(cc, 1 << gpio, value ? 1 << gpio : 0);
  52         return 0;
  53 }
  54
  55 static int bcma_gpio_request(struct gpio_chip *chip, unsigned gpio)
  56 {
  57         struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
  58
  59         bcma_chipco_gpio_control(cc, 1 << gpio, 0);
  60         /* clear pulldown */
  61         bcma_chipco_gpio_pulldown(cc, 1 << gpio, 0);
  62         /* Set pullup */
  63         bcma_chipco_gpio_pullup(cc, 1 << gpio, 1 << gpio);
  64
  65         return 0;
  66 }
  67
  68 static void bcma_gpio_free(struct gpio_chip *chip, unsigned gpio)
  69 {
  70         struct bcma_drv_cc *cc = bcma_gpio_get_cc(chip);
  71
  72         /* clear pullup */
  73         bcma_chipco_gpio_pullup(cc, 1 << gpio, 0);
  74 }
  75
  76 int bcma_gpio_init(struct bcma_drv_cc *cc)
  77 {
  78         struct gpio_chip *chip = &cc->gpio;
  79
  80         chip->label             = "bcma_gpio";
  81         chip->owner             = THIS_MODULE;
  82         chip->request           = bcma_gpio_request;
  83         chip->free              = bcma_gpio_free;
  84         chip->get               = bcma_gpio_get_value;
  85         chip->set               = bcma_gpio_set_value;
  86         chip->direction_input   = bcma_gpio_direction_input;
  87         chip->direction_output  = bcma_gpio_direction_output;
  88         chip->ngpio             = 16;
  89         /* There is just one SoC in one device and its GPIO addresses should be
  90          * deterministic to address them more easily. The other buses could get
  91          * a random base number. */
  92         if (cc->core->bus->hosttype == BCMA_HOSTTYPE_SOC)
  93                 chip->base              = 0;
  94         else
  95                 chip->base              = -1;
  96
  97         return gpiochip_add(chip);
  98 }