1/*
2 * Samsung EXYNOS4x12 FIMC-IS (Imaging Subsystem) driver
3 *
4 * Copyright (C) 2013 Samsung Electronics Co., Ltd.
5 *
6 * Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/clk.h>
14#include <linux/module.h>
15#include <linux/i2c.h>
16#include <linux/platform_device.h>
17#include <linux/pm_runtime.h>
18#include <linux/slab.h>
19#include "fimc-is-i2c.h"
20
21struct fimc_is_i2c {
22	struct i2c_adapter adapter;
23	struct clk *clock;
24};
25
26/*
27 * An empty algorithm is used as the actual I2C bus controller driver
28 * is implemented in the FIMC-IS subsystem firmware and the host CPU
29 * doesn't access the I2C bus controller.
30 */
31static const struct i2c_algorithm fimc_is_i2c_algorithm;
32
33static int fimc_is_i2c_probe(struct platform_device *pdev)
34{
35	struct device_node *node = pdev->dev.of_node;
36	struct fimc_is_i2c *isp_i2c;
37	struct i2c_adapter *i2c_adap;
38	int ret;
39
40	isp_i2c = devm_kzalloc(&pdev->dev, sizeof(*isp_i2c), GFP_KERNEL);
41	if (!isp_i2c)
42		return -ENOMEM;
43
44	isp_i2c->clock = devm_clk_get(&pdev->dev, "i2c_isp");
45	if (IS_ERR(isp_i2c->clock)) {
46		dev_err(&pdev->dev, "failed to get the clock\n");
47		return PTR_ERR(isp_i2c->clock);
48	}
49
50	i2c_adap = &isp_i2c->adapter;
51	i2c_adap->dev.of_node = node;
52	i2c_adap->dev.parent = &pdev->dev;
53	strlcpy(i2c_adap->name, "exynos4x12-isp-i2c", sizeof(i2c_adap->name));
54	i2c_adap->owner = THIS_MODULE;
55	i2c_adap->algo = &fimc_is_i2c_algorithm;
56	i2c_adap->class = I2C_CLASS_SPD;
57
58	ret = i2c_add_adapter(i2c_adap);
59	if (ret < 0) {
60		dev_err(&pdev->dev, "failed to add I2C bus %s\n",
61						node->full_name);
62		return ret;
63	}
64
65	platform_set_drvdata(pdev, isp_i2c);
66
67	pm_runtime_enable(&pdev->dev);
68	pm_runtime_enable(&i2c_adap->dev);
69
70	return 0;
71}
72
73static int fimc_is_i2c_remove(struct platform_device *pdev)
74{
75	struct fimc_is_i2c *isp_i2c = platform_get_drvdata(pdev);
76
77	pm_runtime_disable(&isp_i2c->adapter.dev);
78	pm_runtime_disable(&pdev->dev);
79	i2c_del_adapter(&isp_i2c->adapter);
80
81	return 0;
82}
83
84#if defined(CONFIG_PM_RUNTIME) || defined(CONFIG_PM_SLEEP)
85static int fimc_is_i2c_runtime_suspend(struct device *dev)
86{
87	struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev);
88
89	clk_disable_unprepare(isp_i2c->clock);
90	return 0;
91}
92
93static int fimc_is_i2c_runtime_resume(struct device *dev)
94{
95	struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev);
96
97	return clk_prepare_enable(isp_i2c->clock);
98}
99#endif
100
101#ifdef CONFIG_PM_SLEEP
102static int fimc_is_i2c_suspend(struct device *dev)
103{
104	if (pm_runtime_suspended(dev))
105		return 0;
106
107	return fimc_is_i2c_runtime_suspend(dev);
108}
109
110static int fimc_is_i2c_resume(struct device *dev)
111{
112	if (pm_runtime_suspended(dev))
113		return 0;
114
115	return fimc_is_i2c_runtime_resume(dev);
116}
117#endif
118
119static struct dev_pm_ops fimc_is_i2c_pm_ops = {
120	SET_RUNTIME_PM_OPS(fimc_is_i2c_runtime_suspend,
121					fimc_is_i2c_runtime_resume, NULL)
122	SET_SYSTEM_SLEEP_PM_OPS(fimc_is_i2c_suspend, fimc_is_i2c_resume)
123};
124
125static const struct of_device_id fimc_is_i2c_of_match[] = {
126	{ .compatible = FIMC_IS_I2C_COMPATIBLE },
127	{ },
128};
129
130static struct platform_driver fimc_is_i2c_driver = {
131	.probe		= fimc_is_i2c_probe,
132	.remove		= fimc_is_i2c_remove,
133	.driver = {
134		.of_match_table = fimc_is_i2c_of_match,
135		.name		= "fimc-isp-i2c",
136		.owner		= THIS_MODULE,
137		.pm		= &fimc_is_i2c_pm_ops,
138	}
139};
140
141int fimc_is_register_i2c_driver(void)
142{
143	return platform_driver_register(&fimc_is_i2c_driver);
144}
145
146void fimc_is_unregister_i2c_driver(void)
147{
148	platform_driver_unregister(&fimc_is_i2c_driver);
149}
150