drivers/gpio/bcm2835_gpio.c

   1 /*
   2  * Copyright (C) 2012 Vikram Narayananan
   3  * <vikram186@gmail.com>
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 #include <common.h>
   9 #include <dm.h>
  10 #include <dm/pinctrl.h>
  11 #include <errno.h>
  12 #include <asm/gpio.h>
  13 #include <asm/io.h>
  14 #include <fdtdec.h>
  15
  16 struct bcm2835_gpios {
  17         struct bcm2835_gpio_regs *reg;
  18         struct udevice *pinctrl;
  19 };
  20
  21 static int bcm2835_gpio_direction_input(struct udevice *dev, unsigned gpio)
  22 {
  23         struct bcm2835_gpios *gpios = dev_get_priv(dev);
  24         unsigned val;
  25
  26         val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
  27         val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
  28         val |= (BCM2835_GPIO_INPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
  29         writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
  30
  31         return 0;
  32 }
  33
  34 static int bcm2835_gpio_direction_output(struct udevice *dev, unsigned int gpio,
  35                                          int value)
  36 {
  37         struct bcm2835_gpios *gpios = dev_get_priv(dev);
  38         unsigned val;
  39
  40         gpio_set_value(gpio, value);
  41
  42         val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
  43         val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
  44         val |= (BCM2835_GPIO_OUTPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
  45         writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
  46
  47         return 0;
  48 }
  49
  50 static int bcm2835_get_value(const struct bcm2835_gpios *gpios, unsigned gpio)
  51 {
  52         unsigned val;
  53
  54         val = readl(&gpios->reg->gplev[BCM2835_GPIO_COMMON_BANK(gpio)]);
  55
  56         return (val >> BCM2835_GPIO_COMMON_SHIFT(gpio)) & 0x1;
  57 }
  58
  59 static int bcm2835_gpio_get_value(struct udevice *dev, unsigned gpio)
  60 {
  61         const struct bcm2835_gpios *gpios = dev_get_priv(dev);
  62
  63         return bcm2835_get_value(gpios, gpio);
  64 }
  65
  66 static int bcm2835_gpio_set_value(struct udevice *dev, unsigned gpio,
  67                                   int value)
  68 {
  69         struct bcm2835_gpios *gpios = dev_get_priv(dev);
  70         u32 *output_reg = value ? gpios->reg->gpset : gpios->reg->gpclr;
  71
  72         writel(1 << BCM2835_GPIO_COMMON_SHIFT(gpio),
  73                                 &output_reg[BCM2835_GPIO_COMMON_BANK(gpio)]);
  74
  75         return 0;
  76 }
  77
  78 static int bcm2835_gpio_get_function(struct udevice *dev, unsigned offset)
  79 {
  80         struct bcm2835_gpios *priv = dev_get_priv(dev);
  81         int funcid;
  82
  83         funcid = pinctrl_get_gpio_mux(priv->pinctrl, 0, offset);
  84
  85         switch (funcid) {
  86         case BCM2835_GPIO_OUTPUT:
  87                 return GPIOF_OUTPUT;
  88         case BCM2835_GPIO_INPUT:
  89                 return GPIOF_INPUT;
  90         default:
  91                 return GPIOF_FUNC;
  92         }
  93 }
  94
  95 static const struct dm_gpio_ops gpio_bcm2835_ops = {
  96         .direction_input        = bcm2835_gpio_direction_input,
  97         .direction_output       = bcm2835_gpio_direction_output,
  98         .get_value              = bcm2835_gpio_get_value,
  99         .set_value              = bcm2835_gpio_set_value,
 100         .get_function           = bcm2835_gpio_get_function,
 101 };
 102
 103 static int bcm2835_gpio_probe(struct udevice *dev)
 104 {
 105         struct bcm2835_gpios *gpios = dev_get_priv(dev);
 106         struct bcm2835_gpio_platdata *plat = dev_get_platdata(dev);
 107         struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
 108
 109         uc_priv->bank_name = "GPIO";
 110         uc_priv->gpio_count = BCM2835_GPIO_COUNT;
 111         gpios->reg = (struct bcm2835_gpio_regs *)plat->base;
 112
 113         /* We know we're spawned by the pinctrl driver */
 114         gpios->pinctrl = dev->parent;
 115
 116         return 0;
 117 }
 118
 119 #if CONFIG_IS_ENABLED(OF_CONTROL)
 120 static int bcm2835_gpio_ofdata_to_platdata(struct udevice *dev)
 121 {
 122         struct bcm2835_gpio_platdata *plat = dev_get_platdata(dev);
 123         fdt_addr_t addr;
 124
 125         addr = devfdt_get_addr(dev);
 126         if (addr == FDT_ADDR_T_NONE)
 127                 return -EINVAL;
 128
 129         plat->base = addr;
 130         return 0;
 131 }
 132 #endif
 133
 134 U_BOOT_DRIVER(gpio_bcm2835) = {
 135         .name   = "gpio_bcm2835",
 136         .id     = UCLASS_GPIO,
 137         .ofdata_to_platdata = of_match_ptr(bcm2835_gpio_ofdata_to_platdata),
 138         .platdata_auto_alloc_size = sizeof(struct bcm2835_gpio_platdata),
 139         .ops    = &gpio_bcm2835_ops,
 140         .probe  = bcm2835_gpio_probe,
 141         .flags  = DM_FLAG_PRE_RELOC,
 142         .priv_auto_alloc_size = sizeof(struct bcm2835_gpios),
 143 };