// SPDX-License-Identifier: GPL-2.0+

  /*
   * Copyright 2016 Google Inc.

   */
  
  #include <common.h>
  #include <dm.h>
  #include <errno.h>
  #include <timer.h>
  #include <asm/io.h>
  #include <asm/arch/timer.h>

  #include <linux/err.h>

  #define AST_TICK_TIMER  1
  #define AST_TMC_RELOAD_VAL  0xffffffff
  
  struct ast_timer_priv {
  	struct ast_timer *regs;
  	struct ast_timer_counter *tmc;
  };
  
  static struct ast_timer_counter *ast_get_timer_counter(struct ast_timer *timer,
  						       int n)
  {
  	if (n > 3)
  		return &timer->timers2[n - 4];
  	else
  		return &timer->timers1[n - 1];
  }
  
  static int ast_timer_probe(struct udevice *dev)
  {
  	struct ast_timer_priv *priv = dev_get_priv(dev);
  	struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev);
  
  	writel(AST_TMC_RELOAD_VAL, &priv->tmc->reload_val);
  
  	/*
  	 * Stop the timer. This will also load reload_val into
  	 * the status register.
  	 */
  	clrbits_le32(&priv->regs->ctrl1,
  		     AST_TMC_EN << AST_TMC_CTRL1_SHIFT(AST_TICK_TIMER));
  	/* Start the timer from the fixed 1MHz clock. */
  	setbits_le32(&priv->regs->ctrl1,
  		     (AST_TMC_EN | AST_TMC_1MHZ) <<
  		     AST_TMC_CTRL1_SHIFT(AST_TICK_TIMER));
  
  	uc_priv->clock_rate = AST_TMC_RATE;
  
  	return 0;
  }
  
  static int ast_timer_get_count(struct udevice *dev, u64 *count)
  {
  	struct ast_timer_priv *priv = dev_get_priv(dev);
  
  	*count = AST_TMC_RELOAD_VAL - readl(&priv->tmc->status);
  
  	return 0;
  }
  
  static int ast_timer_ofdata_to_platdata(struct udevice *dev)
  {
  	struct ast_timer_priv *priv = dev_get_priv(dev);

  	priv->regs = devfdt_get_addr_ptr(dev);

  	if (IS_ERR(priv->regs))
  		return PTR_ERR(priv->regs);
  
  	priv->tmc = ast_get_timer_counter(priv->regs, AST_TICK_TIMER);
  
  	return 0;
  }
  
  static const struct timer_ops ast_timer_ops = {
  	.get_count = ast_timer_get_count,
  };
  
  static const struct udevice_id ast_timer_ids[] = {
  	{ .compatible = "aspeed,ast2500-timer" },
  	{ .compatible = "aspeed,ast2400-timer" },
  	{ }
  };
  
  U_BOOT_DRIVER(ast_timer) = {
  	.name = "ast_timer",
  	.id = UCLASS_TIMER,
  	.of_match = ast_timer_ids,
  	.probe = ast_timer_probe,
  	.priv_auto_alloc_size = sizeof(struct ast_timer_priv),
  	.ofdata_to_platdata = ast_timer_ofdata_to_platdata,
  	.ops = &ast_timer_ops,

  };