/*
   * clk-s2mps11.c - Clock driver for S2MPS11.
   *

   * Copyright (C) 2013,2014 Samsung Electornics

   *
   * This program is free software; you can redistribute  it and/or modify it
   * under  the terms of  the GNU General  Public License as published by the
   * Free Software Foundation;  either version 2 of the  License, or (at your
   * option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *

   */
  
  #include <linux/module.h>
  #include <linux/err.h>
  #include <linux/of.h>
  #include <linux/clkdev.h>
  #include <linux/regmap.h>
  #include <linux/clk-provider.h>
  #include <linux/platform_device.h>
  #include <linux/mfd/samsung/s2mps11.h>

  #include <linux/mfd/samsung/s2mps13.h>

  #include <linux/mfd/samsung/s2mps14.h>

  #include <linux/mfd/samsung/s5m8767.h>

  #include <linux/mfd/samsung/core.h>

  enum {
  	S2MPS11_CLK_AP = 0,
  	S2MPS11_CLK_CP,
  	S2MPS11_CLK_BT,
  	S2MPS11_CLKS_NUM,
  };
  
  struct s2mps11_clk {
  	struct sec_pmic_dev *iodev;

  	struct device_node *clk_np;

  	struct clk_hw hw;
  	struct clk *clk;
  	struct clk_lookup *lookup;
  	u32 mask;

  	unsigned int reg;

  };
  
  static struct s2mps11_clk *to_s2mps11_clk(struct clk_hw *hw)
  {
  	return container_of(hw, struct s2mps11_clk, hw);
  }
  
  static int s2mps11_clk_prepare(struct clk_hw *hw)
  {
  	struct s2mps11_clk *s2mps11 = to_s2mps11_clk(hw);

  	return regmap_update_bits(s2mps11->iodev->regmap_pmic,

  				 s2mps11->reg,

  				 s2mps11->mask, s2mps11->mask);

  }
  
  static void s2mps11_clk_unprepare(struct clk_hw *hw)
  {
  	struct s2mps11_clk *s2mps11 = to_s2mps11_clk(hw);

  	regmap_update_bits(s2mps11->iodev->regmap_pmic, s2mps11->reg,

  			   s2mps11->mask, ~s2mps11->mask);

  }

  static int s2mps11_clk_is_prepared(struct clk_hw *hw)

  {

  	int ret;
  	u32 val;

  	struct s2mps11_clk *s2mps11 = to_s2mps11_clk(hw);

  	ret = regmap_read(s2mps11->iodev->regmap_pmic,
  				s2mps11->reg, &val);
  	if (ret < 0)
  		return -EINVAL;
  
  	return val & s2mps11->mask;

  }
  
  static unsigned long s2mps11_clk_recalc_rate(struct clk_hw *hw,
  					     unsigned long parent_rate)
  {

  	return 32768;

  }
  
  static struct clk_ops s2mps11_clk_ops = {
  	.prepare	= s2mps11_clk_prepare,
  	.unprepare	= s2mps11_clk_unprepare,

  	.is_prepared	= s2mps11_clk_is_prepared,

  	.recalc_rate	= s2mps11_clk_recalc_rate,
  };

  /* This s2mps11_clks_init tructure is common to s2mps11, s2mps13 and s2mps14 */

  static struct clk_init_data s2mps11_clks_init[S2MPS11_CLKS_NUM] = {
  	[S2MPS11_CLK_AP] = {
  		.name = "s2mps11_ap",
  		.ops = &s2mps11_clk_ops,

  	},
  	[S2MPS11_CLK_CP] = {
  		.name = "s2mps11_cp",
  		.ops = &s2mps11_clk_ops,

  	},
  	[S2MPS11_CLK_BT] = {
  		.name = "s2mps11_bt",
  		.ops = &s2mps11_clk_ops,

  	},
  };

  static struct device_node *s2mps11_clk_parse_dt(struct platform_device *pdev,
  		struct clk_init_data *clks_init)

  {
  	struct sec_pmic_dev *iodev = dev_get_drvdata(pdev->dev.parent);
  	struct device_node *clk_np;
  	int i;
  
  	if (!iodev->dev->of_node)

  		return ERR_PTR(-EINVAL);

  	clk_np = of_get_child_by_name(iodev->dev->of_node, "clocks");

  	if (!clk_np) {
  		dev_err(&pdev->dev, "could not find clock sub-node
  ");
  		return ERR_PTR(-EINVAL);
  	}

  	for (i = 0; i < S2MPS11_CLKS_NUM; i++)

  		of_property_read_string_index(clk_np, "clock-output-names", i,

  				&clks_init[i].name);

  
  	return clk_np;
  }
  
  static int s2mps11_clk_probe(struct platform_device *pdev)
  {
  	struct sec_pmic_dev *iodev = dev_get_drvdata(pdev->dev.parent);

  	struct s2mps11_clk *s2mps11_clks;

  	struct clk_hw_onecell_data *clk_data;

  	unsigned int s2mps11_reg;

  	int i, ret = 0;

  	enum sec_device_type hwid = platform_get_device_id(pdev)->driver_data;

  	s2mps11_clks = devm_kcalloc(&pdev->dev, S2MPS11_CLKS_NUM,

  				sizeof(*s2mps11_clks), GFP_KERNEL);

  	if (!s2mps11_clks)
  		return -ENOMEM;

  	clk_data = devm_kzalloc(&pdev->dev, sizeof(*clk_data) +
  				sizeof(*clk_data->hws) * S2MPS11_CLKS_NUM,
  				GFP_KERNEL);

  	if (!clk_data)
  		return -ENOMEM;

  	switch (hwid) {

  	case S2MPS11X:
  		s2mps11_reg = S2MPS11_REG_RTC_CTRL;

  		break;

  	case S2MPS13X:
  		s2mps11_reg = S2MPS13_REG_RTCCTRL;

  		break;

  	case S2MPS14X:
  		s2mps11_reg = S2MPS14_REG_RTCCTRL;

  		break;

  	case S5M8767X:
  		s2mps11_reg = S5M8767_REG_CTRL1;
  		break;

  	default:
  		dev_err(&pdev->dev, "Invalid device type
  ");
  		return -EINVAL;

  	}

  	/* Store clocks of_node in first element of s2mps11_clks array */

  	s2mps11_clks->clk_np = s2mps11_clk_parse_dt(pdev, s2mps11_clks_init);

  	if (IS_ERR(s2mps11_clks->clk_np))
  		return PTR_ERR(s2mps11_clks->clk_np);

  	for (i = 0; i < S2MPS11_CLKS_NUM; i++) {

  		if (i == S2MPS11_CLK_CP && hwid == S2MPS14X)

  			continue; /* Skip clocks not present in some devices */

  		s2mps11_clks[i].iodev = iodev;
  		s2mps11_clks[i].hw.init = &s2mps11_clks_init[i];
  		s2mps11_clks[i].mask = 1 << i;
  		s2mps11_clks[i].reg = s2mps11_reg;
  
  		s2mps11_clks[i].clk = devm_clk_register(&pdev->dev,
  							&s2mps11_clks[i].hw);
  		if (IS_ERR(s2mps11_clks[i].clk)) {

  			dev_err(&pdev->dev, "Fail to register : %s
  ",

  						s2mps11_clks_init[i].name);
  			ret = PTR_ERR(s2mps11_clks[i].clk);

  			goto err_reg;
  		}

  		s2mps11_clks[i].lookup = clkdev_hw_create(&s2mps11_clks[i].hw,

  					s2mps11_clks_init[i].name, NULL);
  		if (!s2mps11_clks[i].lookup) {

  			ret = -ENOMEM;

  			goto err_reg;

  		}

  		clk_data->hws[i] = &s2mps11_clks[i].hw;

  	}

  	clk_data->num = S2MPS11_CLKS_NUM;
  	of_clk_add_hw_provider(s2mps11_clks->clk_np, of_clk_hw_onecell_get,
  			       clk_data);

  
  	platform_set_drvdata(pdev, s2mps11_clks);
  
  	return ret;

  err_reg:

  	while (--i >= 0)
  		clkdev_drop(s2mps11_clks[i].lookup);

  
  	return ret;
  }
  
  static int s2mps11_clk_remove(struct platform_device *pdev)
  {
  	struct s2mps11_clk *s2mps11_clks = platform_get_drvdata(pdev);
  	int i;

  	of_clk_del_provider(s2mps11_clks[0].clk_np);
  	/* Drop the reference obtained in s2mps11_clk_parse_dt */
  	of_node_put(s2mps11_clks[0].clk_np);

  	for (i = 0; i < S2MPS11_CLKS_NUM; i++) {
  		/* Skip clocks not present on S2MPS14 */
  		if (!s2mps11_clks[i].lookup)
  			continue;

  		clkdev_drop(s2mps11_clks[i].lookup);

  	}

  
  	return 0;
  }
  
  static const struct platform_device_id s2mps11_clk_id[] = {

  	{ "s2mps11-clk", S2MPS11X},

  	{ "s2mps13-clk", S2MPS13X},

  	{ "s2mps14-clk", S2MPS14X},

  	{ "s5m8767-clk", S5M8767X},

  	{ },
  };
  MODULE_DEVICE_TABLE(platform, s2mps11_clk_id);
  
  static struct platform_driver s2mps11_clk_driver = {
  	.driver = {
  		.name  = "s2mps11-clk",

  	},
  	.probe = s2mps11_clk_probe,
  	.remove = s2mps11_clk_remove,
  	.id_table = s2mps11_clk_id,
  };
  
  static int __init s2mps11_clk_init(void)
  {
  	return platform_driver_register(&s2mps11_clk_driver);
  }
  subsys_initcall(s2mps11_clk_init);

  static void __exit s2mps11_clk_cleanup(void)

  {
  	platform_driver_unregister(&s2mps11_clk_driver);
  }
  module_exit(s2mps11_clk_cleanup);
  
  MODULE_DESCRIPTION("S2MPS11 Clock Driver");
  MODULE_AUTHOR("Yadwinder Singh Brar <yadi.brar@samsung.com>");
  MODULE_LICENSE("GPL");