text: /*
   * Synopsys DesignWare I2C adapter driver (master only).
   *
   * Based on the TI DAVINCI I2C adapter driver.
   *
   * Copyright (C) 2006 Texas Instruments.
   * Copyright (C) 2007 MontaVista Software Inc.
   * Copyright (C) 2009 Provigent Ltd.
   *
   * ----------------------------------------------------------------------------
   *
   * 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.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
   * ----------------------------------------------------------------------------
   *
   */
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/delay.h>
  #include <linux/i2c.h>
  #include <linux/clk.h>
  #include <linux/errno.h>
  #include <linux/sched.h>
  #include <linux/err.h>
  #include <linux/interrupt.h>
  #include <linux/of_i2c.h>
  #include <linux/platform_device.h>
  #include <linux/pm.h>
  #include <linux/pm_runtime.h>
  #include <linux/io.h>
  #include <linux/slab.h>
  #include <linux/acpi.h>
  #include "i2c-designware-core.h"
  
  static struct i2c_algorithm i2c_dw_algo = {
  	.master_xfer	= i2c_dw_xfer,
  	.functionality	= i2c_dw_func,
  };
  static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
  {
  	return clk_get_rate(dev->clk)/1000;
  }
  
  #ifdef CONFIG_ACPI
  static int dw_i2c_acpi_configure(struct platform_device *pdev)
  {
  	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
  
  	if (!ACPI_HANDLE(&pdev->dev))
  		return -ENODEV;
  
  	dev->adapter.nr = -1;
  	dev->tx_fifo_depth = 32;
  	dev->rx_fifo_depth = 32;
  	return 0;
  }
  
  static const struct acpi_device_id dw_i2c_acpi_match[] = {
  	{ "INT33C2", 0 },
  	{ "INT33C3", 0 },
  	{ "80860F41", 0 },
  	{ }
  };
  MODULE_DEVICE_TABLE(acpi, dw_i2c_acpi_match);
  #else
  static inline int dw_i2c_acpi_configure(struct platform_device *pdev)
  {
  	return -ENODEV;
  }
  #endif
  
  static int dw_i2c_probe(struct platform_device *pdev)
  {
  	struct dw_i2c_dev *dev;
  	struct i2c_adapter *adap;
  	struct resource *mem;
  	int irq, r;
  
  	/* NOTE: driver uses the static register mapping */
  	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  	if (!mem) {
  		dev_err(&pdev->dev, "no mem resource?\n");
  		return -EINVAL;
  	}
  
  	irq = platform_get_irq(pdev, 0);
  	if (irq < 0) {
  		dev_err(&pdev->dev, "no irq resource?\n");
  		return irq; /* -ENXIO */
  	}
  
  	dev = devm_kzalloc(&pdev->dev, sizeof(struct dw_i2c_dev), GFP_KERNEL);
  	if (!dev)
  		return -ENOMEM;
  
  	dev->base = devm_ioremap_resource(&pdev->dev, mem);
  	if (IS_ERR(dev->base))
  		return PTR_ERR(dev->base);
  
  	init_completion(&dev->cmd_complete);
  	mutex_init(&dev->lock);
  	dev->dev = &pdev->dev;
  	dev->irq = irq;
  	platform_set_drvdata(pdev, dev);
  
  	dev->clk = devm_clk_get(&pdev->dev, NULL);
  	dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
  
  	if (IS_ERR(dev->clk))
  		return PTR_ERR(dev->clk);
  	clk_prepare_enable(dev->clk);
  
  	dev->functionality =
  		I2C_FUNC_I2C |
  		I2C_FUNC_10BIT_ADDR |
  		I2C_FUNC_SMBUS_BYTE |
  		I2C_FUNC_SMBUS_BYTE_DATA |
  		I2C_FUNC_SMBUS_WORD_DATA |
  		I2C_FUNC_SMBUS_I2C_BLOCK;
  	dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
  		DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
  
  	/* Try first if we can configure the device from ACPI */
  	r = dw_i2c_acpi_configure(pdev);
  	if (r) {
  		u32 param1 = i2c_dw_read_comp_param(dev);
  
  		dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
  		dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
  		dev->adapter.nr = pdev->id;
  	}
  	r = i2c_dw_init(dev);
  	if (r)
  		return r;
  
  	i2c_dw_disable_int(dev);
  	r = devm_request_irq(&pdev->dev, dev->irq, i2c_dw_isr, IRQF_SHARED,
  			pdev->name, dev);
  	if (r) {
  		dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
  		return r;
  	}
  
  	adap = &dev->adapter;
  	i2c_set_adapdata(adap, dev);
  	adap->owner = THIS_MODULE;
  	adap->class = I2C_CLASS_HWMON;
  	strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
  			sizeof(adap->name));
  	adap->algo = &i2c_dw_algo;
  	adap->dev.parent = &pdev->dev;
  	adap->dev.of_node = pdev->dev.of_node;
  
  	r = i2c_add_numbered_adapter(adap);
  	if (r) {
  		dev_err(&pdev->dev, "failure adding adapter\n");
  		return r;
  	}
  	of_i2c_register_devices(adap);
  	acpi_i2c_register_devices(adap);
  
  	pm_runtime_set_autosuspend_delay(&pdev->dev, 1000);
  	pm_runtime_use_autosuspend(&pdev->dev);
  	pm_runtime_set_active(&pdev->dev);
  	pm_runtime_enable(&pdev->dev);
  
  	return 0;
  }
  
  static int dw_i2c_remove(struct platform_device *pdev)
  {
  	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
  
  	pm_runtime_get_sync(&pdev->dev);
  
  	i2c_del_adapter(&dev->adapter);
  
  	i2c_dw_disable(dev);
  
  	pm_runtime_put(&pdev->dev);
  	pm_runtime_disable(&pdev->dev);
  
  	return 0;
  }
  
  #ifdef CONFIG_OF
  static const struct of_device_id dw_i2c_of_match[] = {
  	{ .compatible = "snps,designware-i2c", },
  	{},
  };
  MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
  #endif
  
  #ifdef CONFIG_PM
  static int dw_i2c_suspend(struct device *dev)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
  
  	clk_disable_unprepare(i_dev->clk);
  
  	return 0;
  }
  
  static int dw_i2c_resume(struct device *dev)
  {
  	struct platform_device *pdev = to_platform_device(dev);
  	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
  
  	clk_prepare_enable(i_dev->clk);
  	i2c_dw_init(i_dev);
  
  	return 0;
  }
  #endif
  
  static SIMPLE_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend, dw_i2c_resume);
  
  /* work with hotplug and coldplug */
  MODULE_ALIAS("platform:i2c_designware");
  
  static struct platform_driver dw_i2c_driver = {
  	.remove		= dw_i2c_remove,
  	.driver		= {
  		.name	= "i2c_designware",
  		.owner	= THIS_MODULE,
  		.of_match_table = of_match_ptr(dw_i2c_of_match),
  		.acpi_match_table = ACPI_PTR(dw_i2c_acpi_match),
  		.pm	= &dw_i2c_dev_pm_ops,
  	},
  };
  
  static int __init dw_i2c_init_driver(void)
  {
  	return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
  }
  subsys_initcall(dw_i2c_init_driver);
  
  static void __exit dw_i2c_exit_driver(void)
  {
  	platform_driver_unregister(&dw_i2c_driver);
  }
  module_exit(dw_i2c_exit_driver);
  
  MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
  MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
  MODULE_LICENSE("GPL");
  