text: // SPDX-License-Identifier: GPL-2.0
  /*
   * Copyright (C) 2018 Alexander Graf <agraf@suse.de>
   *
   * Based on drivers/pinctrl/mvebu/pinctrl-mvebu.c and
   *          drivers/gpio/bcm2835_gpio.c
   *
   * This driver gets instantiated by the GPIO driver, because both devices
   * share the same device node.
   * https://spdx.org/licenses
   */
  
  #include <common.h>
  #include <config.h>
  #include <errno.h>
  #include <dm.h>
  #include <log.h>
  #include <dm/pinctrl.h>
  #include <dm/root.h>
  #include <dm/device-internal.h>
  #include <dm/lists.h>
  #include <asm/system.h>
  #include <asm/io.h>
  #include <asm/gpio.h>
  
  struct bcm283x_pinctrl_priv {
  	u32 *base_reg;
  };
  
  #define MAX_PINS_PER_BANK 16
  
  static void bcm2835_gpio_set_func_id(struct udevice *dev, unsigned int gpio,
  				     int func)
  {
  	struct bcm283x_pinctrl_priv *priv = dev_get_priv(dev);
  	int reg_offset;
  	int field_offset;
  
  	reg_offset = BCM2835_GPIO_FSEL_BANK(gpio);
  	field_offset = BCM2835_GPIO_FSEL_SHIFT(gpio);
  
  	clrsetbits_le32(&priv->base_reg[reg_offset],
  			BCM2835_GPIO_FSEL_MASK << field_offset,
  			(func & BCM2835_GPIO_FSEL_MASK) << field_offset);
  }
  
  static int bcm2835_gpio_get_func_id(struct udevice *dev, unsigned int gpio)
  {
  	struct bcm283x_pinctrl_priv *priv = dev_get_priv(dev);
  	u32 val;
  
  	val = readl(&priv->base_reg[BCM2835_GPIO_FSEL_BANK(gpio)]);
  
  	return (val >> BCM2835_GPIO_FSEL_SHIFT(gpio) & BCM2835_GPIO_FSEL_MASK);
  }
  
  /*
   * bcm283x_pinctrl_set_state: configure pin functions.
   * @dev: the pinctrl device to be configured.
   * @config: the state to be configured.
   * @return: 0 in success
   */
  int bcm283x_pinctrl_set_state(struct udevice *dev, struct udevice *config)
  {
  	u32 pin_arr[MAX_PINS_PER_BANK];
  	int function;
  	int i, len, pin_count = 0;
  
  	if (!dev_read_prop(config, "brcm,pins", &len) || !len ||
  	    len & 0x3 || dev_read_u32_array(config, "brcm,pins", pin_arr,
  						  len / sizeof(u32))) {
  		debug("Failed reading pins array for pinconfig %s (%d)\n",
  		      config->name, len);
  		return -EINVAL;
  	}
  
  	pin_count = len / sizeof(u32);
  
  	function = dev_read_u32_default(config, "brcm,function", -1);
  	if (function < 0) {
  		debug("Failed reading function for pinconfig %s (%d)\n",
  		      config->name, function);
  		return -EINVAL;
  	}
  
  	for (i = 0; i < pin_count; i++)
  		bcm2835_gpio_set_func_id(dev, pin_arr[i], function);
  
  	return 0;
  }
  
  static int bcm283x_pinctrl_get_gpio_mux(struct udevice *dev, int banknum,
  					int index)
  {
  	if (banknum != 0)
  		return -EINVAL;
  
  	return bcm2835_gpio_get_func_id(dev, index);
  }
  
  static const struct udevice_id bcm2835_pinctrl_id[] = {
  	{.compatible = "brcm,bcm2835-gpio"},
  	{.compatible = "brcm,bcm2711-gpio"},
  	{}
  };
  
  int bcm283x_pinctl_of_to_plat(struct udevice *dev)
  {
  	struct bcm283x_pinctrl_priv *priv;
  
  	priv = dev_get_priv(dev);
  
  	priv->base_reg = dev_read_addr_ptr(dev);
  	if (!priv->base_reg) {
  		debug("%s: Failed to get base address\n", __func__);
  		return -EINVAL;
  	}
  
  	return 0;
  }
  
  int bcm283x_pinctl_probe(struct udevice *dev)
  {
  	int ret;
  	struct udevice *pdev;
  
  	/* Create GPIO device as well */
  	ret = device_bind(dev, lists_driver_lookup_name("gpio_bcm2835"),
  			  "gpio_bcm2835", NULL, dev_ofnode(dev), &pdev);
  	if (ret) {
  		/*
  		 * While we really want the pinctrl driver to work to make
  		 * devices go where they should go, the GPIO controller is
  		 * not quite as crucial as it's only rarely used, so don't
  		 * fail here.
  		 */
  		printf("Failed to bind GPIO driver\n");
  	}
  
  	return 0;
  }
  
  static struct pinctrl_ops bcm283x_pinctrl_ops = {
  	.set_state	= bcm283x_pinctrl_set_state,
  	.get_gpio_mux	= bcm283x_pinctrl_get_gpio_mux,
  };
  
  U_BOOT_DRIVER(pinctrl_bcm283x) = {
  	.name		= "bcm283x_pinctrl",
  	.id		= UCLASS_PINCTRL,
  	.of_match	= of_match_ptr(bcm2835_pinctrl_id),
  	.of_to_plat = bcm283x_pinctl_of_to_plat,
  	.priv_auto	= sizeof(struct bcm283x_pinctrl_priv),
  	.ops		= &bcm283x_pinctrl_ops,
  	.probe		= bcm283x_pinctl_probe,
  #if CONFIG_IS_ENABLED(OF_BOARD)
  	.flags		= DM_FLAG_PRE_RELOC,
  #endif
  };
  