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[media] exynos4-is: Add FIMC-IS ISP I2C bus driver

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This patch adds the ISP I2C bus controller driver files.
Creating a standard I2C bus adapter, even if the driver doesn't
actually communicate with the hardware and it is instead
controlled by the ISP firmware running on the Cortex-A5, allows
to use standard hardware description in the device tree. As the
sensor would have actually had a standard V4L2 sub-device driver
run on the host CPU.
This approach allows to adapt the driver with a relatively small
effort should the Imaging Subsystem architecture change so that
the I2C bus is handled by the host's CPU OS, rather than the
internal FIMC-IS ARM CPU firmware. The image sensor driver could
be a standard I2C client driver, as in case of most existing
image sensors.

Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Sylwester Nawrocki 2013-03-11 15:28:18 -03:00 committed by Mauro Carvalho Chehab
parent 9a761e4368
commit da114376d3
2 changed files with 144 additions and 0 deletions
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129
drivers/media/platform/exynos4-is/fimc-is-i2c.c Normal file
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/*
* Samsung EXYNOS4x12 FIMC-IS (Imaging Subsystem) driver
*
* Copyright (C) 2013 Samsung Electronics Co., Ltd.
*
* Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/of_i2c.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/slab.h>
#include "fimc-is-i2c.h"
struct fimc_is_i2c {
struct i2c_adapter adapter;
struct clk *clock;
};
/*
* An empty algorithm is used as the actual I2C bus controller driver
* is implemented in the FIMC-IS subsystem firmware and the host CPU
* doesn't access the I2C bus controller.
*/
static const struct i2c_algorithm fimc_is_i2c_algorithm;
static int fimc_is_i2c_probe(struct platform_device *pdev)
{
struct device_node *node = pdev->dev.of_node;
struct fimc_is_i2c *isp_i2c;
struct i2c_adapter *i2c_adap;
int ret;
isp_i2c = devm_kzalloc(&pdev->dev, sizeof(*isp_i2c), GFP_KERNEL);
if (!isp_i2c)
return -ENOMEM;
isp_i2c->clock = devm_clk_get(&pdev->dev, "i2c_isp");
if (IS_ERR(isp_i2c->clock)) {
dev_err(&pdev->dev, "failed to get the clock\n");
return PTR_ERR(isp_i2c->clock);
}
i2c_adap = &isp_i2c->adapter;
i2c_adap->dev.of_node = node;
i2c_adap->dev.parent = &pdev->dev;
strlcpy(i2c_adap->name, "exynos4x12-isp-i2c", sizeof(i2c_adap->name));
i2c_adap->owner = THIS_MODULE;
i2c_adap->algo = &fimc_is_i2c_algorithm;
i2c_adap->class = I2C_CLASS_SPD;
ret = i2c_add_adapter(i2c_adap);
if (ret < 0) {
dev_err(&pdev->dev, "failed to add I2C bus %s\n",
node->full_name);
return ret;
}
platform_set_drvdata(pdev, isp_i2c);
pm_runtime_enable(&pdev->dev);
pm_runtime_enable(&i2c_adap->dev);
of_i2c_register_devices(i2c_adap);
return 0;
}
static int fimc_is_i2c_remove(struct platform_device *pdev)
{
struct fimc_is_i2c *isp_i2c = platform_get_drvdata(pdev);
pm_runtime_disable(&isp_i2c->adapter.dev);
pm_runtime_disable(&pdev->dev);
i2c_del_adapter(&isp_i2c->adapter);
return 0;
}
static int fimc_is_i2c_suspend(struct device *dev)
{
struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev);
clk_disable_unprepare(isp_i2c->clock);
return 0;
}
static int fimc_is_i2c_resume(struct device *dev)
{
struct fimc_is_i2c *isp_i2c = dev_get_drvdata(dev);
return clk_prepare_enable(isp_i2c->clock);
}
UNIVERSAL_DEV_PM_OPS(fimc_is_i2c_pm_ops, fimc_is_i2c_suspend,
fimc_is_i2c_resume, NULL);
static const struct of_device_id fimc_is_i2c_of_match[] = {
{ .compatible = FIMC_IS_I2C_COMPATIBLE },
{ },
};
MODULE_DEVICE_TABLE(of, fimc_is_i2c_of_match);
static struct platform_driver fimc_is_i2c_driver = {
.probe = fimc_is_i2c_probe,
.remove = fimc_is_i2c_remove,
.driver = {
.of_match_table = fimc_is_i2c_of_match,
.name = "fimc-isp-i2c",
.owner = THIS_MODULE,
.pm = &fimc_is_i2c_pm_ops,
}
};
int fimc_is_register_i2c_driver(void)
{
return platform_driver_register(&fimc_is_i2c_driver);
}
EXPORT_SYMBOL(fimc_is_register_i2c_driver);
void fimc_is_unregister_i2c_driver(void)
{
platform_driver_unregister(&fimc_is_i2c_driver);
}
EXPORT_SYMBOL(fimc_is_unregister_i2c_driver);

15
drivers/media/platform/exynos4-is/fimc-is-i2c.h Normal file
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/*
* Samsung EXYNOS4x12 FIMC-IS (Imaging Subsystem) driver
*
* Copyright (C) 2013 Samsung Electronics Co., Ltd.
* Sylwester Nawrocki <s.nawrocki@samsung.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#define FIMC_IS_I2C_COMPATIBLE "samsung,exynos4212-i2c-isp"
int fimc_is_register_i2c_driver(void);
void fimc_is_unregister_i2c_driver(void);