aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/i2c/busses/i2c-designware-platdrv.c
blob: 2d3657ab1258534d307c8ab00b0dfd1718c5ce72 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
/*
 * 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/platform_device.h>
#include <linux/io.h>
#include <linux/slab.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;
}

static int __devinit dw_i2c_probe(struct platform_device *pdev)
{
	struct dw_i2c_dev *dev;
	struct i2c_adapter *adap;
	struct resource *mem, *ioarea;
	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 */
	}

	ioarea = request_mem_region(mem->start, resource_size(mem),
			pdev->name);
	if (!ioarea) {
		dev_err(&pdev->dev, "I2C region already claimed\n");
		return -EBUSY;
	}

	dev = kzalloc(sizeof(struct dw_i2c_dev), GFP_KERNEL);
	if (!dev) {
		r = -ENOMEM;
		goto err_release_region;
	}

	init_completion(&dev->cmd_complete);
	mutex_init(&dev->lock);
	dev->dev = get_device(&pdev->dev);
	dev->irq = irq;
	platform_set_drvdata(pdev, dev);

	dev->clk = clk_get(&pdev->dev, NULL);
	dev->get_clk_rate_khz = i2c_dw_get_clk_rate_khz;

	if (IS_ERR(dev->clk)) {
		r = -ENODEV;
		goto err_free_mem;
	}
	clk_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;

	dev->base = ioremap(mem->start, resource_size(mem));
	if (dev->base == NULL) {
		dev_err(&pdev->dev, "failure mapping io resources\n");
		r = -EBUSY;
		goto err_unuse_clocks;
	}
	{
		u32 param1 = i2c_dw_read_comp_param(dev);

		dev->tx_fifo_depth = ((param1 >> 16) & 0xff) + 1;
		dev->rx_fifo_depth = ((param1 >> 8)  & 0xff) + 1;
	}
	r = i2c_dw_init(dev);
	if (r)
		goto err_iounmap;

	i2c_dw_disable_int(dev);
	r = request_irq(dev->irq, i2c_dw_isr, IRQF_DISABLED, pdev->name, dev);
	if (r) {
		dev_err(&pdev->dev, "failure requesting irq %i\n", dev->irq);
		goto err_iounmap;
	}

	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->nr = pdev->id;
	r = i2c_add_numbered_adapter(adap);
	if (r) {
		dev_err(&pdev->dev, "failure adding adapter\n");
		goto err_free_irq;
	}

	return 0;

err_free_irq:
	free_irq(dev->irq, dev);
err_iounmap:
	iounmap(dev->base);
err_unuse_clocks:
	clk_disable(dev->clk);
	clk_put(dev->clk);
	dev->clk = NULL;
err_free_mem:
	platform_set_drvdata(pdev, NULL);
	put_device(&pdev->dev);
	kfree(dev);
err_release_region:
	release_mem_region(mem->start, resource_size(mem));

	return r;
}

static int __devexit dw_i2c_remove(struct platform_device *pdev)
{
	struct dw_i2c_dev *dev = platform_get_drvdata(pdev);
	struct resource *mem;

	platform_set_drvdata(pdev, NULL);
	i2c_del_adapter(&dev->adapter);
	put_device(&pdev->dev);

	clk_disable(dev->clk);
	clk_put(dev->clk);
	dev->clk = NULL;

	i2c_dw_disable(dev);
	free_irq(dev->irq, dev);
	kfree(dev);

	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	release_mem_region(mem->start, resource_size(mem));
	return 0;
}

/* work with hotplug and coldplug */
MODULE_ALIAS("platform:i2c_designware");

static struct platform_driver dw_i2c_driver = {
	.remove		= __devexit_p(dw_i2c_remove),
	.driver		= {
		.name	= "i2c_designware",
		.owner	= THIS_MODULE,
	},
};

static int __init dw_i2c_init_driver(void)
{
	return platform_driver_probe(&dw_i2c_driver, dw_i2c_probe);
}
module_init(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");