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 <errno.h>
  11 #include <asm/gpio.h>
  12 #include <asm/io.h>
  13 #include <fdtdec.h>
  14
  15 struct bcm2835_gpios {
  16         struct bcm2835_gpio_regs *reg;
  17 };
  18
  19 static int bcm2835_gpio_direction_input(struct udevice *dev, unsigned gpio)
  20 {
  21         struct bcm2835_gpios *gpios = dev_get_priv(dev);
  22         unsigned val;
  23
  24         val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
  25         val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
  26         val |= (BCM2835_GPIO_INPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
  27         writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
  28
  29         return 0;
  30 }
  31
  32 static int bcm2835_gpio_direction_output(struct udevice *dev, unsigned gpio,
  33                                          int value)
  34 {
  35         struct bcm2835_gpios *gpios = dev_get_priv(dev);
  36         unsigned val;
  37
  38         gpio_set_value(gpio, value);
  39
  40         val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
  41         val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
  42         val |= (BCM2835_GPIO_OUTPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
  43         writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
  44
  45         return 0;
  46 }
  47
  48 static int bcm2835_get_value(const struct bcm2835_gpios *gpios, unsigned gpio)
  49 {
  50         unsigned val;
  51
  52         val = readl(&gpios->reg->gplev[BCM2835_GPIO_COMMON_BANK(gpio)]);
  53
  54         return (val >> BCM2835_GPIO_COMMON_SHIFT(gpio)) & 0x1;
  55 }
  56
  57 static int bcm2835_gpio_get_value(struct udevice *dev, unsigned gpio)
  58 {
  59         const struct bcm2835_gpios *gpios = dev_get_priv(dev);
  60
  61         return bcm2835_get_value(gpios, gpio);
  62 }
  63
  64 static int bcm2835_gpio_set_value(struct udevice *dev, unsigned gpio,
  65                                   int value)
  66 {
  67         struct bcm2835_gpios *gpios = dev_get_priv(dev);
  68         u32 *output_reg = value ? gpios->reg->gpset : gpios->reg->gpclr;
  69
  70         writel(1 << BCM2835_GPIO_COMMON_SHIFT(gpio),
  71                                 &output_reg[BCM2835_GPIO_COMMON_BANK(gpio)]);
  72
  73         return 0;
  74 }
  75
  76 int bcm2835_gpio_get_func_id(struct udevice *dev, unsigned gpio)
  77 {
  78         struct bcm2835_gpios *gpios = dev_get_priv(dev);
  79         u32 val;
  80
  81         val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
  82
  83         return (val >> BCM2835_GPIO_FSEL_SHIFT(gpio) & BCM2835_GPIO_FSEL_MASK);
  84 }
  85
  86 static int bcm2835_gpio_get_function(struct udevice *dev, unsigned offset)
  87 {
  88         int funcid = bcm2835_gpio_get_func_id(dev, offset);
  89
  90         switch (funcid) {
  91         case BCM2835_GPIO_OUTPUT:
  92                 return GPIOF_OUTPUT;
  93         case BCM2835_GPIO_INPUT:
  94                 return GPIOF_INPUT;
  95         default:
  96                 return GPIOF_FUNC;
  97         }
  98 }
  99
 100
 101 static const struct dm_gpio_ops gpio_bcm2835_ops = {
 102         .direction_input        = bcm2835_gpio_direction_input,
 103         .direction_output       = bcm2835_gpio_direction_output,
 104         .get_value              = bcm2835_gpio_get_value,
 105         .set_value              = bcm2835_gpio_set_value,
 106         .get_function           = bcm2835_gpio_get_function,
 107 };
 108
 109 static int bcm2835_gpio_probe(struct udevice *dev)
 110 {
 111         struct bcm2835_gpios *gpios = dev_get_priv(dev);
 112         struct bcm2835_gpio_platdata *plat = dev_get_platdata(dev);
 113         struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
 114
 115         uc_priv->bank_name = "GPIO";
 116         uc_priv->gpio_count = BCM2835_GPIO_COUNT;
 117         gpios->reg = (struct bcm2835_gpio_regs *)plat->base;
 118
 119         return 0;
 120 }
 121
 122 #if CONFIG_IS_ENABLED(OF_CONTROL)
 123 static const struct udevice_id bcm2835_gpio_id[] = {
 124         {.compatible = "brcm,bcm2835-gpio"},
 125         {}
 126 };
 127
 128 static int bcm2835_gpio_ofdata_to_platdata(struct udevice *dev)
 129 {
 130         struct bcm2835_gpio_platdata *plat = dev_get_platdata(dev);
 131         fdt_addr_t addr;
 132
 133         addr = devfdt_get_addr(dev);
 134         if (addr == FDT_ADDR_T_NONE)
 135                 return -EINVAL;
 136
 137         plat->base = addr;
 138         return 0;
 139 }
 140 #endif
 141
 142 U_BOOT_DRIVER(gpio_bcm2835) = {
 143         .name   = "gpio_bcm2835",
 144         .id     = UCLASS_GPIO,
 145         .of_match = of_match_ptr(bcm2835_gpio_id),
 146         .ofdata_to_platdata = of_match_ptr(bcm2835_gpio_ofdata_to_platdata),
 147         .platdata_auto_alloc_size = sizeof(struct bcm2835_gpio_platdata),
 148         .ops    = &gpio_bcm2835_ops,
 149         .probe  = bcm2835_gpio_probe,
 150         .flags  = DM_FLAG_PRE_RELOC,
 151         .priv_auto_alloc_size = sizeof(struct bcm2835_gpios),
 152 };