// SPDX-License-Identifier: GPL-2.0+
  //
  // soc-ac97.c  --  ALSA SoC Audio Layer AC97 support
  //
  // Copyright 2005 Wolfson Microelectronics PLC.
  // Copyright 2005 Openedhand Ltd.
  // Copyright (C) 2010 Slimlogic Ltd.
  // Copyright (C) 2010 Texas Instruments Inc.
  //
  // Author: Liam Girdwood <lrg@slimlogic.co.uk>
  //         with code, comments and ideas from :-
  //         Richard Purdie <richard@openedhand.com>

  
  #include <linux/ctype.h>
  #include <linux/delay.h>
  #include <linux/export.h>
  #include <linux/gpio.h>

  #include <linux/gpio/driver.h>

  #include <linux/init.h>
  #include <linux/of_gpio.h>
  #include <linux/of.h>
  #include <linux/pinctrl/consumer.h>
  #include <linux/slab.h>
  #include <sound/ac97_codec.h>
  #include <sound/soc.h>
  
  struct snd_ac97_reset_cfg {
  	struct pinctrl *pctl;
  	struct pinctrl_state *pstate_reset;
  	struct pinctrl_state *pstate_warm_reset;
  	struct pinctrl_state *pstate_run;
  	int gpio_sdata;
  	int gpio_sync;
  	int gpio_reset;
  };

  struct snd_ac97_gpio_priv {
  #ifdef CONFIG_GPIOLIB
  	struct gpio_chip gpio_chip;
  #endif
  	unsigned int gpios_set;

  	struct snd_soc_component *component;

  };

  static struct snd_ac97_bus soc_ac97_bus = {
  	.ops = NULL, /* Gets initialized in snd_soc_set_ac97_ops() */
  };

  static void soc_ac97_device_release(struct device *dev)
  {
  	kfree(to_ac97_t(dev));
  }

  #ifdef CONFIG_GPIOLIB

  static inline struct snd_soc_component *gpio_to_component(struct gpio_chip *chip)

  {

  	struct snd_ac97_gpio_priv *gpio_priv = gpiochip_get_data(chip);

  	return gpio_priv->component;

  }
  
  static int snd_soc_ac97_gpio_request(struct gpio_chip *chip, unsigned offset)
  {
  	if (offset >= AC97_NUM_GPIOS)
  		return -EINVAL;
  
  	return 0;
  }
  
  static int snd_soc_ac97_gpio_direction_in(struct gpio_chip *chip,
  					  unsigned offset)
  {

  	struct snd_soc_component *component = gpio_to_component(chip);

  	dev_dbg(component->dev, "set gpio %d to output
  ", offset);
  	return snd_soc_component_update_bits(component, AC97_GPIO_CFG,

  				   1 << offset, 1 << offset);
  }
  
  static int snd_soc_ac97_gpio_get(struct gpio_chip *chip, unsigned offset)
  {

  	struct snd_soc_component *component = gpio_to_component(chip);

  	int ret;

  	ret = snd_soc_component_read(component, AC97_GPIO_STATUS);

  
  	dev_dbg(component->dev, "get gpio %d : %d
  ", offset,

  		ret & (1 << offset));

  	return !!(ret & (1 << offset));

  }
  
  static void snd_soc_ac97_gpio_set(struct gpio_chip *chip, unsigned offset,
  				  int value)
  {

  	struct snd_ac97_gpio_priv *gpio_priv = gpiochip_get_data(chip);

  	struct snd_soc_component *component = gpio_to_component(chip);

  
  	gpio_priv->gpios_set &= ~(1 << offset);
  	gpio_priv->gpios_set |= (!!value) << offset;

  	snd_soc_component_write(component, AC97_GPIO_STATUS,
  				gpio_priv->gpios_set);
  	dev_dbg(component->dev, "set gpio %d to %d
  ", offset, !!value);

  }
  
  static int snd_soc_ac97_gpio_direction_out(struct gpio_chip *chip,
  				     unsigned offset, int value)
  {

  	struct snd_soc_component *component = gpio_to_component(chip);

  	dev_dbg(component->dev, "set gpio %d to output
  ", offset);

  	snd_soc_ac97_gpio_set(chip, offset, value);

  	return snd_soc_component_update_bits(component, AC97_GPIO_CFG,
  					     1 << offset, 0);

  }

  static const struct gpio_chip snd_soc_ac97_gpio_chip = {

  	.label			= "snd_soc_ac97",
  	.owner			= THIS_MODULE,
  	.request		= snd_soc_ac97_gpio_request,
  	.direction_input	= snd_soc_ac97_gpio_direction_in,
  	.get			= snd_soc_ac97_gpio_get,
  	.direction_output	= snd_soc_ac97_gpio_direction_out,
  	.set			= snd_soc_ac97_gpio_set,
  	.can_sleep		= 1,
  };
  
  static int snd_soc_ac97_init_gpio(struct snd_ac97 *ac97,

  				  struct snd_soc_component *component)

  {
  	struct snd_ac97_gpio_priv *gpio_priv;
  	int ret;

  	gpio_priv = devm_kzalloc(component->dev, sizeof(*gpio_priv), GFP_KERNEL);

  	if (!gpio_priv)
  		return -ENOMEM;
  	ac97->gpio_priv = gpio_priv;

  	gpio_priv->component = component;

  	gpio_priv->gpio_chip = snd_soc_ac97_gpio_chip;
  	gpio_priv->gpio_chip.ngpio = AC97_NUM_GPIOS;

  	gpio_priv->gpio_chip.parent = component->dev;

  	gpio_priv->gpio_chip.base = -1;

  	ret = gpiochip_add_data(&gpio_priv->gpio_chip, gpio_priv);

  	if (ret != 0)

  		dev_err(component->dev, "Failed to add GPIOs: %d
  ", ret);

  	return ret;
  }
  
  static void snd_soc_ac97_free_gpio(struct snd_ac97 *ac97)
  {
  	gpiochip_remove(&ac97->gpio_priv->gpio_chip);
  }
  #else
  static int snd_soc_ac97_init_gpio(struct snd_ac97 *ac97,

  				  struct snd_soc_component *component)

  {
  	return 0;
  }
  
  static void snd_soc_ac97_free_gpio(struct snd_ac97 *ac97)
  {
  }
  #endif

  /**

   * snd_soc_alloc_ac97_component() - Allocate new a AC'97 device
   * @component: The COMPONENT for which to create the AC'97 device

   *

   * Allocated a new snd_ac97 device and intializes it, but does not yet register
   * it. The caller is responsible to either call device_add(&ac97->dev) to
   * register the device, or to call put_device(&ac97->dev) to free the device.
   *
   * Returns: A snd_ac97 device or a PTR_ERR in case of an error.

   */

  struct snd_ac97 *snd_soc_alloc_ac97_component(struct snd_soc_component *component)

  {

  	struct snd_ac97 *ac97;

  	ac97 = kzalloc(sizeof(struct snd_ac97), GFP_KERNEL);
  	if (ac97 == NULL)
  		return ERR_PTR(-ENOMEM);

  	ac97->bus = &soc_ac97_bus;
  	ac97->num = 0;

  	ac97->dev.bus = &ac97_bus_type;

  	ac97->dev.parent = component->card->dev;

  	ac97->dev.release = soc_ac97_device_release;

  	dev_set_name(&ac97->dev, "%d-%d:%s",

  		     component->card->snd_card->number, 0,
  		     component->name);

  	device_initialize(&ac97->dev);
  
  	return ac97;
  }

  EXPORT_SYMBOL(snd_soc_alloc_ac97_component);

  
  /**

   * snd_soc_new_ac97_component - initailise AC97 device
   * @component: audio component

   * @id: The expected device ID
   * @id_mask: Mask that is applied to the device ID before comparing with @id

   *

   * Initialises AC97 component resources for use by ad-hoc devices only.

   *
   * If @id is not 0 this function will reset the device, then read the ID from
   * the device and check if it matches the expected ID. If it doesn't match an
   * error will be returned and device will not be registered.
   *
   * Returns: A PTR_ERR() on failure or a valid snd_ac97 struct on success.

   */

  struct snd_ac97 *snd_soc_new_ac97_component(struct snd_soc_component *component,

  	unsigned int id, unsigned int id_mask)

  {
  	struct snd_ac97 *ac97;
  	int ret;

  	ac97 = snd_soc_alloc_ac97_component(component);

  	if (IS_ERR(ac97))
  		return ac97;

  	if (id) {
  		ret = snd_ac97_reset(ac97, false, id, id_mask);
  		if (ret < 0) {

  			dev_err(component->dev, "Failed to reset AC97 device: %d
  ",

  				ret);
  			goto err_put_device;
  		}

  	}

  	ret = device_add(&ac97->dev);
  	if (ret)
  		goto err_put_device;

  	ret = snd_soc_ac97_init_gpio(ac97, component);

  	if (ret)
  		goto err_put_device;

  	return ac97;

  
  err_put_device:
  	put_device(&ac97->dev);
  	return ERR_PTR(ret);

  }

  EXPORT_SYMBOL_GPL(snd_soc_new_ac97_component);

  
  /**

   * snd_soc_free_ac97_component - free AC97 component device

   * @ac97: snd_ac97 device to be freed

   *

   * Frees AC97 component device resources.

   */

  void snd_soc_free_ac97_component(struct snd_ac97 *ac97)

  {

  	snd_soc_ac97_free_gpio(ac97);

  	device_del(&ac97->dev);
  	ac97->bus = NULL;
  	put_device(&ac97->dev);

  }

  EXPORT_SYMBOL_GPL(snd_soc_free_ac97_component);

  
  static struct snd_ac97_reset_cfg snd_ac97_rst_cfg;
  
  static void snd_soc_ac97_warm_reset(struct snd_ac97 *ac97)
  {
  	struct pinctrl *pctl = snd_ac97_rst_cfg.pctl;
  
  	pinctrl_select_state(pctl, snd_ac97_rst_cfg.pstate_warm_reset);
  
  	gpio_direction_output(snd_ac97_rst_cfg.gpio_sync, 1);
  
  	udelay(10);
  
  	gpio_direction_output(snd_ac97_rst_cfg.gpio_sync, 0);
  
  	pinctrl_select_state(pctl, snd_ac97_rst_cfg.pstate_run);
  	msleep(2);
  }
  
  static void snd_soc_ac97_reset(struct snd_ac97 *ac97)
  {
  	struct pinctrl *pctl = snd_ac97_rst_cfg.pctl;
  
  	pinctrl_select_state(pctl, snd_ac97_rst_cfg.pstate_reset);
  
  	gpio_direction_output(snd_ac97_rst_cfg.gpio_sync, 0);
  	gpio_direction_output(snd_ac97_rst_cfg.gpio_sdata, 0);
  	gpio_direction_output(snd_ac97_rst_cfg.gpio_reset, 0);
  
  	udelay(10);
  
  	gpio_direction_output(snd_ac97_rst_cfg.gpio_reset, 1);
  
  	pinctrl_select_state(pctl, snd_ac97_rst_cfg.pstate_run);
  	msleep(2);
  }
  
  static int snd_soc_ac97_parse_pinctl(struct device *dev,
  		struct snd_ac97_reset_cfg *cfg)
  {
  	struct pinctrl *p;
  	struct pinctrl_state *state;
  	int gpio;
  	int ret;
  
  	p = devm_pinctrl_get(dev);
  	if (IS_ERR(p)) {
  		dev_err(dev, "Failed to get pinctrl
  ");
  		return PTR_ERR(p);
  	}
  	cfg->pctl = p;
  
  	state = pinctrl_lookup_state(p, "ac97-reset");
  	if (IS_ERR(state)) {
  		dev_err(dev, "Can't find pinctrl state ac97-reset
  ");
  		return PTR_ERR(state);
  	}
  	cfg->pstate_reset = state;
  
  	state = pinctrl_lookup_state(p, "ac97-warm-reset");
  	if (IS_ERR(state)) {
  		dev_err(dev, "Can't find pinctrl state ac97-warm-reset
  ");
  		return PTR_ERR(state);
  	}
  	cfg->pstate_warm_reset = state;
  
  	state = pinctrl_lookup_state(p, "ac97-running");
  	if (IS_ERR(state)) {
  		dev_err(dev, "Can't find pinctrl state ac97-running
  ");
  		return PTR_ERR(state);
  	}
  	cfg->pstate_run = state;
  
  	gpio = of_get_named_gpio(dev->of_node, "ac97-gpios", 0);
  	if (gpio < 0) {
  		dev_err(dev, "Can't find ac97-sync gpio
  ");
  		return gpio;
  	}
  	ret = devm_gpio_request(dev, gpio, "AC97 link sync");
  	if (ret) {
  		dev_err(dev, "Failed requesting ac97-sync gpio
  ");
  		return ret;
  	}
  	cfg->gpio_sync = gpio;
  
  	gpio = of_get_named_gpio(dev->of_node, "ac97-gpios", 1);
  	if (gpio < 0) {
  		dev_err(dev, "Can't find ac97-sdata gpio %d
  ", gpio);
  		return gpio;
  	}
  	ret = devm_gpio_request(dev, gpio, "AC97 link sdata");
  	if (ret) {
  		dev_err(dev, "Failed requesting ac97-sdata gpio
  ");
  		return ret;
  	}
  	cfg->gpio_sdata = gpio;
  
  	gpio = of_get_named_gpio(dev->of_node, "ac97-gpios", 2);
  	if (gpio < 0) {
  		dev_err(dev, "Can't find ac97-reset gpio
  ");
  		return gpio;
  	}
  	ret = devm_gpio_request(dev, gpio, "AC97 link reset");
  	if (ret) {
  		dev_err(dev, "Failed requesting ac97-reset gpio
  ");
  		return ret;
  	}
  	cfg->gpio_reset = gpio;
  
  	return 0;
  }
  
  struct snd_ac97_bus_ops *soc_ac97_ops;
  EXPORT_SYMBOL_GPL(soc_ac97_ops);
  
  int snd_soc_set_ac97_ops(struct snd_ac97_bus_ops *ops)
  {
  	if (ops == soc_ac97_ops)
  		return 0;
  
  	if (soc_ac97_ops && ops)
  		return -EBUSY;
  
  	soc_ac97_ops = ops;

  	soc_ac97_bus.ops = ops;

  
  	return 0;
  }
  EXPORT_SYMBOL_GPL(snd_soc_set_ac97_ops);
  
  /**
   * snd_soc_set_ac97_ops_of_reset - Set ac97 ops with generic ac97 reset functions

   * @ops: bus ops
   * @pdev: platform device

   *
   * This function sets the reset and warm_reset properties of ops and parses
   * the device node of pdev to get pinctrl states and gpio numbers to use.
   */
  int snd_soc_set_ac97_ops_of_reset(struct snd_ac97_bus_ops *ops,
  		struct platform_device *pdev)
  {
  	struct device *dev = &pdev->dev;
  	struct snd_ac97_reset_cfg cfg;
  	int ret;
  
  	ret = snd_soc_ac97_parse_pinctl(dev, &cfg);
  	if (ret)
  		return ret;
  
  	ret = snd_soc_set_ac97_ops(ops);
  	if (ret)
  		return ret;
  
  	ops->warm_reset = snd_soc_ac97_warm_reset;
  	ops->reset = snd_soc_ac97_reset;
  
  	snd_ac97_rst_cfg = cfg;
  	return 0;
  }
  EXPORT_SYMBOL_GPL(snd_soc_set_ac97_ops_of_reset);