1/*
  2 * Synopsys DesignWare I2C adapter driver (master only).
  3 *
  4 * Based on the TI DAVINCI I2C adapter driver.
  5 *
  6 * Copyright (C) 2006 Texas Instruments.
  7 * Copyright (C) 2007 MontaVista Software Inc.
  8 * Copyright (C) 2009 Provigent Ltd.
  9 *
 10 * ----------------------------------------------------------------------------
 11 *
 12 * This program is free software; you can redistribute it and/or modify
 13 * it under the terms of the GNU General Public License as published by
 14 * the Free Software Foundation; either version 2 of the License, or
 15 * (at your option) any later version.
 16 *
 17 * This program is distributed in the hope that it will be useful,
 18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 20 * GNU General Public License for more details.
 21 *
 22 * You should have received a copy of the GNU General Public License
 23 * along with this program; if not, write to the Free Software
 24 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 25 * ----------------------------------------------------------------------------
 26 *
 27 */
 28#include <linux/kernel.h>
 29#include <linux/module.h>
 30#include <linux/delay.h>
 31#include <linux/i2c.h>
 32#include <linux/clk.h>
 33#include <linux/errno.h>
 34#include <linux/sched.h>
 35#include <linux/err.h>
 36#include <linux/interrupt.h>
 37#include <linux/of_i2c.h>
 38#include <linux/platform_device.h>
 39#include <linux/pm.h>
 40#include <linux/io.h>
 41#include <linux/slab.h>
 42#include "i2c-designware-core.h"
 43
 44static struct i2c_algorithm i2c_dw_algo = {
 45	.master_xfer	= i2c_dw_xfer,
 46	.functionality	= i2c_dw_func,
 47};
 48static u32 i2c_dw_get_clk_rate_khz(struct dw_i2c_dev *dev)
 49{
 50	return clk_get_rate(dev->clk)/1000;
 51}
 52
 53static int __devinit dw_i2c_probe(struct platform_device *pdev)
 54{
 55	struct dw_i2c_dev *dev;
 56	struct i2c_adapter *adap;
 57	struct resource *mem, *ioarea;
 58	int irq, r;
 59
 60	/* NOTE: driver uses the static register mapping */
 61	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 62	if (!mem) {
 63		dev_err(&pdev->dev, "no mem resource?\n");
 64		return -EINVAL;
 65	}
 66
 67	irq = platform_get_irq(pdev, 0);
 68	if (irq < 0) {
 69		dev_err(&pdev->dev, "no irq resource?\n");
 70		return irq; /* -ENXIO */
 71	}
 72
 73	ioarea = request_mem_region(mem->start, resource_size(mem),
 74			pdev->name);
 75	if (!ioarea) {
 76		dev_err(&pdev->dev, "I2C region already claimed\n");
 77		return -EBUSY;
 78	}
 79
 80	dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
 81	if (!dev) {
 82		r = -ENOMEM;
 83		goto err_release_region;
 84	}
 85
 86	init_completion(&dev->cmd_complete);
 87	mutex_init(&dev->lock);
 88	dev->dev = get_device(&pdev->dev);
 89	dev->irq = irq;
 90	platform_set_drvdata(pdev, dev);
 91
 92	dev->clk = clk_get(&pdev->dev, NULL);
 93	dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;
 94
 95	if (IS_ERR(dev->clk)) {
 96		r = -ENODEV;
 97		goto err_free_mem;
 98	}
 99	clk_prepare_enable(dev->clk);
100
101	dev->functionality =
102		I2C_FUNC_I2C |
103		I2C_FUNC_10BIT_ADDR |
104		I2C_FUNC_SMBUS_BYTE |
105		I2C_FUNC_SMBUS_BYTE_DATA |
106		I2C_FUNC_SMBUS_WORD_DATA |
107		I2C_FUNC_SMBUS_I2C_BLOCK;
108	dev->master_cfg =  DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE |
109		DW_IC_CON_RESTART_EN | DW_IC_CON_SPEED_FAST;
110
111	dev->base = ioremap(mem->start, resource_size(mem));
112	if (dev->base == NULL) {
113		dev_err(&pdev->dev, "failure mapping io resources\n");
114		r = -EBUSY;
115		goto err_unuse_clocks;
116	}
117	{
118		u32 param1 = i2c_dw_read_comp_param(dev);
119
120		dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
121		dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
122	}
123	r = i2c_dw_init(dev);
124	if (r)
125		goto err_iounmap;
126
127	i2c_dw_disable_int(dev);
128	r = request_irq(dev->irq, i2c_dw_isr, IRQF_DISABLED, pdev->name, dev);
129	if (r) {
130		dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
131		goto err_iounmap;
132	}
133
134	adap = &dev->adapter;
135	i2c_set_adapdata(adap, dev);
136	adap->owner = THIS_MODULE;
137	adap->class = I2C_CLASS_HWMON;
138	strlcpy(adap->name, "Synopsys DesignWare I2C adapter",
139			sizeof(adap->name));
140	adap->algo = &i2c_dw_algo;
141	adap->dev.parent = &pdev->dev;
142	adap->dev.of_node = pdev->dev.of_node;
143
144	adap->nr = pdev->id;
145	r = i2c_add_numbered_adapter(adap);
146	if (r) {
147		dev_err(&pdev->dev, "failure adding adapter\n");
148		goto err_free_irq;
149	}
150	of_i2c_register_devices(adap);
151
152	return 0;
153
154err_free_irq:
155	free_irq(dev->irq, dev);
156err_iounmap:
157	iounmap(dev->base);
158err_unuse_clocks:
159	clk_disable_unprepare(dev->clk);
160	clk_put(dev->clk);
161	dev->clk = NULL;
162err_free_mem:
163	platform_set_drvdata(pdev, NULL);
164	put_device(&pdev->dev);
165	kfree(dev);
166err_release_region:
167	release_mem_region(mem->start, resource_size(mem));
168
169	return r;
170}
171
172static int __devexit dw_i2c_remove(struct platform_device *pdev)
173{
174	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
175	struct resource *mem;
176
177	platform_set_drvdata(pdev, NULL);
178	i2c_del_adapter(&dev->adapter);
179	put_device(&pdev->dev);
180
181	clk_disable_unprepare(dev->clk);
182	clk_put(dev->clk);
183	dev->clk = NULL;
184
185	i2c_dw_disable(dev);
186	free_irq(dev->irq, dev);
187	kfree(dev);
188
189	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
190	release_mem_region(mem->start, resource_size(mem));
191	return 0;
192}
193
194#ifdef CONFIG_OF
195static const struct of_device_id dw_i2c_of_match[] = {
196	{ .compatible = "snps,designware-i2c", },
197	{},
198};
199MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
200#endif
201
202#ifdef CONFIG_PM
203static int dw_i2c_suspend(struct device *dev)
204{
205	struct platform_device *pdev = to_platform_device(dev);
206	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
207
208	clk_disable_unprepare(i_dev->clk);
209
210	return 0;
211}
212
213static int dw_i2c_resume(struct device *dev)
214{
215	struct platform_device *pdev = to_platform_device(dev);
216	struct dw_i2c_dev *i_dev = platform_get_drvdata(pdev);
217
218	clk_prepare_enable(i_dev->clk);
219	i2c_dw_init(i_dev);
220
221	return 0;
222}
223#endif
224
225static SIMPLE_DEV_PM_OPS(dw_i2c_dev_pm_ops, dw_i2c_suspend, dw_i2c_resume);
226
227/* work with hotplug and coldplug */
228MODULE_ALIAS("platform:i2c_designware");
229
230static struct platform_driver dw_i2c_driver = {
231	.remove		= __devexit_p(dw_i2c_remove),
232	.driver		= {
233		.name	= "i2c_designware",
234		.owner	= THIS_MODULE,
235		.of_match_table = of_match_ptr(dw_i2c_of_match),
236		.pm	= &dw_i2c_dev_pm_ops,
237	},
238};
239
240static int __init dw_i2c_init_driver(void)
241{
242	return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
243}
244subsys_initcall(dw_i2c_init_driver);
245
246static void __exit dw_i2c_exit_driver(void)
247{
248	platform_driver_unregister(&dw_i2c_driver);
249}
250module_exit(dw_i2c_exit_driver);
251
252MODULE_AUTHOR("Baruch Siach <baruch@tkos.co.il>");
253MODULE_DESCRIPTION("Synopsys DesignWare I2C bus adapter");
254MODULE_LICENSE("GPL");