This patch adds the ISP I2C bus controller driver files. Creating a standard I2C bus adapter, even if the driver doesn't actually communicates with the hardware and it is instead used 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 controlled by the host CPU, rather than the internal FIMC-IS ARM CPU. The image sensor drivers can be standard I2C client driver, as in case of most existing image sensor driver. Signed-off-by: Sylwester Nawrocki <s.nawro...@samsung.com> Signed-off-by: Kyungmin Park <kyungmin.p...@samsung.com> --- drivers/media/platform/s5p-fimc/fimc-is-i2c.c | 81 +++++++++++++++++++++++++ drivers/media/platform/s5p-fimc/fimc-is-i2c.h | 15 +++++ 2 files changed, 96 insertions(+) create mode 100644 drivers/media/platform/s5p-fimc/fimc-is-i2c.c create mode 100644 drivers/media/platform/s5p-fimc/fimc-is-i2c.h diff --git a/drivers/media/platform/s5p-fimc/fimc-is-i2c.c b/drivers/media/platform/s5p-fimc/fimc-is-i2c.c new file mode 100644 index 0000000..d4c75dc --- /dev/null +++ b/drivers/media/platform/s5p-fimc/fimc-is-i2c.c @@ -0,0 +1,81 @@ +/* + * Samsung EXYNOS4x12 FIMC-IS (Imaging Subsystem) driver + * + * Copyright (C) 2013 Samsung Electronics Co., Ltd. + * Sylwester Nawrocki <s.nawro...@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 pr_fmt(fmt) "%s:%d " fmt, __func__, __LINE__ + +#include <linux/module.h> +#include <linux/of_i2c.h> +#include <linux/platform_device.h> +#include "fimc-is-i2c.h" + +/* + * 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 touch the hardware. + */ +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 i2c_adapter *i2c_adap; + int ret; + + i2c_adap = devm_kzalloc(&pdev->dev, sizeof(*i2c_adap), GFP_KERNEL); + + i2c_adap->dev.of_node = node; + i2c_adap->dev.parent = &pdev->dev; + strlcpy(i2c_adap->name, "exynos4x12-is-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; + } + of_i2c_register_devices(i2c_adap); + + return 0; +} + +static int fimc_is_i2c_remove(struct platform_device *pdev) +{ + return 0; +} + +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-is-i2c", + .owner = THIS_MODULE, + } +}; + +int fimc_is_register_i2c_driver(void) +{ + return platform_driver_register(&fimc_is_i2c_driver); +} + +void fimc_is_unregister_i2c_driver(void) +{ + platform_driver_unregister(&fimc_is_i2c_driver); +} + diff --git a/drivers/media/platform/s5p-fimc/fimc-is-i2c.h b/drivers/media/platform/s5p-fimc/fimc-is-i2c.h new file mode 100644 index 0000000..0d38d6b --- /dev/null +++ b/drivers/media/platform/s5p-fimc/fimc-is-i2c.h @@ -0,0 +1,15 @@ +/* + * Samsung EXYNOS4x12 FIMC-IS (Imaging Subsystem) driver + * + * Copyright (C) 2013 Samsung Electronics Co., Ltd. + * Sylwester Nawrocki <s.nawro...@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); -- 1.7.9.5 _______________________________________________ devicetree-discuss mailing list devicetree-discuss@lists.ozlabs.org https://lists.ozlabs.org/listinfo/devicetree-discuss