1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Samsung EXYNOS4x12 FIMC-IS (Imaging Subsystem) driver
4 *
5 * Copyright (C) 2013 Samsung Electronics Co., Ltd.
6 *
7 * Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
8 */
9
10 #include <linux/clk.h>
11 #include <linux/module.h>
12 #include <linux/i2c.h>
13 #include <linux/platform_device.h>
14 #include <linux/pm_runtime.h>
15 #include <linux/slab.h>
16 #include "fimc-is-i2c.h"
17
18 struct fimc_is_i2c {
19 struct i2c_adapter adapter;
20 struct clk *clock;
21 };
22
23 /*
24 * An empty algorithm is used as the actual I2C bus controller driver
25 * is implemented in the FIMC-IS subsystem firmware and the host CPU
26 * doesn't access the I2C bus controller.
27 */
is_i2c_func(struct i2c_adapter * adap)28 static u32 is_i2c_func(struct i2c_adapter *adap)
29 {
30 return I2C_FUNC_I2C;
31 }
32
33 static const struct i2c_algorithm fimc_is_i2c_algorithm = {
34 .functionality = is_i2c_func,
35 };
36
fimc_is_i2c_probe(struct platform_device * pdev)37 static int fimc_is_i2c_probe(struct platform_device *pdev)
38 {
39 struct device_node *node = pdev->dev.of_node;
40 struct fimc_is_i2c *isp_i2c;
41 struct i2c_adapter *i2c_adap;
42 int ret;
43
44 isp_i2c = devm_kzalloc(&pdev->dev, sizeof(*isp_i2c), GFP_KERNEL);
45 if (!isp_i2c)
46 return -ENOMEM;
47
48 isp_i2c->clock = devm_clk_get(&pdev->dev, "i2c_isp");
49 if (IS_ERR(isp_i2c->clock)) {
50 dev_err(&pdev->dev, "failed to get the clock\n");
51 return PTR_ERR(isp_i2c->clock);
52 }
53
54 i2c_adap = &isp_i2c->adapter;
55 i2c_adap->dev.of_node = node;
56 i2c_adap->dev.parent = &pdev->dev;
57 strscpy(i2c_adap->name, "exynos4x12-isp-i2c", sizeof(i2c_adap->name));
58 i2c_adap->owner = THIS_MODULE;
59 i2c_adap->algo = &fimc_is_i2c_algorithm;
60 i2c_adap->class = I2C_CLASS_SPD;
61
62 platform_set_drvdata(pdev, isp_i2c);
63 pm_runtime_enable(&pdev->dev);
64
65 ret = i2c_add_adapter(i2c_adap);
66 if (ret < 0)
67 goto err_pm_dis;
68 /*
69 * Client drivers of this adapter don't do any I2C transfers as that
70 * is handled by the ISP firmware. But we rely on the runtime PM
71 * state propagation from the clients up to the adapter driver so
72 * clear the ignore_children flags here. PM rutnime calls are not
73 * used in probe() handler of clients of this adapter so there is
74 * no issues with clearing the flag right after registering the I2C
75 * adapter.
76 */
77 pm_suspend_ignore_children(&i2c_adap->dev, false);
78 return 0;
79
80 err_pm_dis:
81 pm_runtime_disable(&pdev->dev);
82 return ret;
83 }
84
fimc_is_i2c_remove(struct platform_device * pdev)85 static void fimc_is_i2c_remove(struct platform_device *pdev)
86 {
87 struct fimc_is_i2c *isp_i2c = platform_get_drvdata(pdev);
88
89 pm_runtime_disable(&pdev->dev);
90 i2c_del_adapter(&isp_i2c->adapter);
91 }
92
93 #ifdef CONFIG_PM
fimc_is_i2c_runtime_suspend(struct device * dev)94 static int fimc_is_i2c_runtime_suspend(struct device *dev)
95 {
96 struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev);
97
98 clk_disable_unprepare(isp_i2c->clock);
99 return 0;
100 }
101
fimc_is_i2c_runtime_resume(struct device * dev)102 static int fimc_is_i2c_runtime_resume(struct device *dev)
103 {
104 struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev);
105
106 return clk_prepare_enable(isp_i2c->clock);
107 }
108 #endif
109
110 #ifdef CONFIG_PM_SLEEP
fimc_is_i2c_suspend(struct device * dev)111 static int fimc_is_i2c_suspend(struct device *dev)
112 {
113 if (pm_runtime_suspended(dev))
114 return 0;
115
116 return fimc_is_i2c_runtime_suspend(dev);
117 }
118
fimc_is_i2c_resume(struct device * dev)119 static int fimc_is_i2c_resume(struct device *dev)
120 {
121 if (pm_runtime_suspended(dev))
122 return 0;
123
124 return fimc_is_i2c_runtime_resume(dev);
125 }
126 #endif
127
128 static const struct dev_pm_ops fimc_is_i2c_pm_ops = {
129 SET_RUNTIME_PM_OPS(fimc_is_i2c_runtime_suspend,
130 fimc_is_i2c_runtime_resume, NULL)
131 SET_SYSTEM_SLEEP_PM_OPS(fimc_is_i2c_suspend, fimc_is_i2c_resume)
132 };
133
134 static const struct of_device_id fimc_is_i2c_of_match[] = {
135 { .compatible = FIMC_IS_I2C_COMPATIBLE },
136 { },
137 };
138
139 static struct platform_driver fimc_is_i2c_driver = {
140 .probe = fimc_is_i2c_probe,
141 .remove_new = fimc_is_i2c_remove,
142 .driver = {
143 .of_match_table = fimc_is_i2c_of_match,
144 .name = "fimc-isp-i2c",
145 .pm = &fimc_is_i2c_pm_ops,
146 }
147 };
148
fimc_is_register_i2c_driver(void)149 int fimc_is_register_i2c_driver(void)
150 {
151 return platform_driver_register(&fimc_is_i2c_driver);
152 }
153
fimc_is_unregister_i2c_driver(void)154 void fimc_is_unregister_i2c_driver(void)
155 {
156 platform_driver_unregister(&fimc_is_i2c_driver);
157 }
158