fimc-is-i2c.c

  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
 18struct 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 */
 28static u32 is_i2c_func(struct i2c_adapter *adap)
 29{
 30	return I2C_FUNC_I2C;
 31}
 32
 33static const struct i2c_algorithm fimc_is_i2c_algorithm = {
 34	.functionality	= is_i2c_func,
 35};
 36
 37static 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
 61	platform_set_drvdata(pdev, isp_i2c);
 62	pm_runtime_enable(&pdev->dev);
 63
 64	ret = i2c_add_adapter(i2c_adap);
 65	if (ret < 0)
 66		goto err_pm_dis;
 67	/*
 68	 * Client drivers of this adapter don't do any I2C transfers as that
 69	 * is handled by the ISP firmware.  But we rely on the runtime PM
 70	 * state propagation from the clients up to the adapter driver so
 71	 * clear the ignore_children flags here.  PM rutnime calls are not
 72	 * used in probe() handler of clients of this adapter so there is
 73	 * no issues with clearing the flag right after registering the I2C
 74	 * adapter.
 75	 */
 76	pm_suspend_ignore_children(&i2c_adap->dev, false);
 77	return 0;
 78
 79err_pm_dis:
 80	pm_runtime_disable(&pdev->dev);
 81	return ret;
 82}
 83
 84static void fimc_is_i2c_remove(struct platform_device *pdev)
 85{
 86	struct fimc_is_i2c *isp_i2c = platform_get_drvdata(pdev);
 87
 88	pm_runtime_disable(&pdev->dev);
 89	i2c_del_adapter(&isp_i2c->adapter);
 90}
 91
 92#ifdef CONFIG_PM
 93static int fimc_is_i2c_runtime_suspend(struct device *dev)
 94{
 95	struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev);
 96
 97	clk_disable_unprepare(isp_i2c->clock);
 98	return 0;
 99}
100
101static int fimc_is_i2c_runtime_resume(struct device *dev)
102{
103	struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev);
104
105	return clk_prepare_enable(isp_i2c->clock);
106}
107#endif
108
109#ifdef CONFIG_PM_SLEEP
110static int fimc_is_i2c_suspend(struct device *dev)
111{
112	if (pm_runtime_suspended(dev))
113		return 0;
114
115	return fimc_is_i2c_runtime_suspend(dev);
116}
117
118static int fimc_is_i2c_resume(struct device *dev)
119{
120	if (pm_runtime_suspended(dev))
121		return 0;
122
123	return fimc_is_i2c_runtime_resume(dev);
124}
125#endif
126
127static const struct dev_pm_ops fimc_is_i2c_pm_ops = {
128	SET_RUNTIME_PM_OPS(fimc_is_i2c_runtime_suspend,
129					fimc_is_i2c_runtime_resume, NULL)
130	SET_SYSTEM_SLEEP_PM_OPS(fimc_is_i2c_suspend, fimc_is_i2c_resume)
131};
132
133static const struct of_device_id fimc_is_i2c_of_match[] = {
134	{ .compatible = "samsung,exynos4212-i2c-isp" },
135	{ },
136};
137
138static struct platform_driver fimc_is_i2c_driver = {
139	.probe		= fimc_is_i2c_probe,
140	.remove		= fimc_is_i2c_remove,
141	.driver = {
142		.of_match_table = fimc_is_i2c_of_match,
143		.name		= "fimc-isp-i2c",
144		.pm		= &fimc_is_i2c_pm_ops,
145	}
146};
147
148int fimc_is_register_i2c_driver(void)
149{
150	return platform_driver_register(&fimc_is_i2c_driver);
151}
152
153void fimc_is_unregister_i2c_driver(void)
154{
155	platform_driver_unregister(&fimc_is_i2c_driver);
156}