uboot/drivers/gpio/bcm2835_gpio.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Copyright (C) 2012 Vikram Narayananan
   4 * <vikram186@gmail.com>
   5 */
   6
   7#include <common.h>
   8#include <dm.h>
   9#include <dm/pinctrl.h>
  10#include <errno.h>
  11#include <asm/gpio.h>
  12#include <asm/io.h>
  13#include <fdtdec.h>
  14
  15struct bcm2835_gpios {
  16        struct bcm2835_gpio_regs *reg;
  17        struct udevice *pinctrl;
  18};
  19
  20static int bcm2835_gpio_direction_input(struct udevice *dev, unsigned gpio)
  21{
  22        struct bcm2835_gpios *gpios = dev_get_priv(dev);
  23        unsigned val;
  24
  25        val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
  26        val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
  27        val |= (BCM2835_GPIO_INPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
  28        writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
  29
  30        return 0;
  31}
  32
  33static int bcm2835_gpio_direction_output(struct udevice *dev, unsigned int gpio,
  34                                         int value)
  35{
  36        struct bcm2835_gpios *gpios = dev_get_priv(dev);
  37        unsigned val;
  38
  39        gpio_set_value(gpio, value);
  40
  41        val = readl(&gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
  42        val &= ~(BCM2835_GPIO_FSEL_MASK << BCM2835_GPIO_FSEL_SHIFT(gpio));
  43        val |= (BCM2835_GPIO_OUTPUT << BCM2835_GPIO_FSEL_SHIFT(gpio));
  44        writel(val, &gpios->reg->gpfsel[BCM2835_GPIO_FSEL_BANK(gpio)]);
  45
  46        return 0;
  47}
  48
  49static int bcm2835_get_value(const struct bcm2835_gpios *gpios, unsigned gpio)
  50{
  51        unsigned val;
  52
  53        val = readl(&gpios->reg->gplev[BCM2835_GPIO_COMMON_BANK(gpio)]);
  54
  55        return (val >> BCM2835_GPIO_COMMON_SHIFT(gpio)) & 0x1;
  56}
  57
  58static int bcm2835_gpio_get_value(struct udevice *dev, unsigned gpio)
  59{
  60        const struct bcm2835_gpios *gpios = dev_get_priv(dev);
  61
  62        return bcm2835_get_value(gpios, gpio);
  63}
  64
  65static int bcm2835_gpio_set_value(struct udevice *dev, unsigned gpio,
  66                                  int value)
  67{
  68        struct bcm2835_gpios *gpios = dev_get_priv(dev);
  69        u32 *output_reg = value ? gpios->reg->gpset : gpios->reg->gpclr;
  70
  71        writel(1 << BCM2835_GPIO_COMMON_SHIFT(gpio),
  72                                &output_reg[BCM2835_GPIO_COMMON_BANK(gpio)]);
  73
  74        return 0;
  75}
  76
  77static int bcm2835_gpio_get_function(struct udevice *dev, unsigned offset)
  78{
  79        struct bcm2835_gpios *priv = dev_get_priv(dev);
  80        int funcid;
  81
  82        funcid = pinctrl_get_gpio_mux(priv->pinctrl, 0, offset);
  83
  84        switch (funcid) {
  85        case BCM2835_GPIO_OUTPUT:
  86                return GPIOF_OUTPUT;
  87        case BCM2835_GPIO_INPUT:
  88                return GPIOF_INPUT;
  89        default:
  90                return GPIOF_FUNC;
  91        }
  92}
  93
  94static const struct dm_gpio_ops gpio_bcm2835_ops = {
  95        .direction_input        = bcm2835_gpio_direction_input,
  96        .direction_output       = bcm2835_gpio_direction_output,
  97        .get_value              = bcm2835_gpio_get_value,
  98        .set_value              = bcm2835_gpio_set_value,
  99        .get_function           = bcm2835_gpio_get_function,
 100};
 101
 102static int bcm2835_gpio_probe(struct udevice *dev)
 103{
 104        struct bcm2835_gpios *gpios = dev_get_priv(dev);
 105        struct bcm2835_gpio_plat *plat = dev_get_plat(dev);
 106        struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
 107
 108        uc_priv->bank_name = "GPIO";
 109        uc_priv->gpio_count = BCM2835_GPIO_COUNT;
 110        gpios->reg = (struct bcm2835_gpio_regs *)plat->base;
 111
 112        /* We know we're spawned by the pinctrl driver */
 113        gpios->pinctrl = dev->parent;
 114
 115        return 0;
 116}
 117
 118#if CONFIG_IS_ENABLED(OF_CONTROL)
 119static int bcm2835_gpio_of_to_plat(struct udevice *dev)
 120{
 121        struct bcm2835_gpio_plat *plat = dev_get_plat(dev);
 122        fdt_addr_t addr;
 123
 124        addr = dev_read_addr(dev);
 125        if (addr == FDT_ADDR_T_NONE)
 126                return -EINVAL;
 127
 128        plat->base = addr;
 129        return 0;
 130}
 131#endif
 132
 133U_BOOT_DRIVER(gpio_bcm2835) = {
 134        .name   = "gpio_bcm2835",
 135        .id     = UCLASS_GPIO,
 136        .of_to_plat = of_match_ptr(bcm2835_gpio_of_to_plat),
 137        .plat_auto      = sizeof(struct bcm2835_gpio_plat),
 138        .ops    = &gpio_bcm2835_ops,
 139        .probe  = bcm2835_gpio_probe,
 140        .flags  = DM_FLAG_PRE_RELOC,
 141        .priv_auto      = sizeof(struct bcm2835_gpios),
 142};
 143