[PATCH RFC] arm: omap3evm: Add support for an MT9M032 based camera board.

[Laurent Pinchart]

Hi Martin,

Thanks for the patch.

On Tuesday 18 January 2011 23:32:16 Martin Hostettler wrote:
> Adds board support for an MT9M032 based camera to omap3evm.
> 
> Sigend-off-by: Martin Hostettler <martin at neutronstar.dyndns.org>
> ---
>  arch/arm/mach-omap2/Makefile                |    1 +
>  arch/arm/mach-omap2/board-omap3evm-camera.c |  177 ++++++++++++++++++++++++
>  2 files changed, 178 insertions(+), 0 deletions(-)
>  create mode 100644 arch/arm/mach-omap2/board-omap3evm-camera.c

Is there a special reason to add camera support to a separate file ?

Of course not all OMAP3 EVM systems will use an MT9M032 sensor, so some kind 
of modularity (and if possible runtime configuration) will be needed.

[snip]

> diff --git a/arch/arm/mach-omap2/board-omap3evm-camera.c
> b/arch/arm/mach-omap2/board-omap3evm-camera.c new file mode 100644
> index 0000000..ea82a49
> --- /dev/null
> +++ b/arch/arm/mach-omap2/board-omap3evm-camera.c
> @@ -0,0 +1,177 @@

[snip]


> +/*
> + * Copyright (C) 2010-2011 Lund Engineering
> + * Contact: Gil Lund <gwlund at lundeng.com>
> + * Author: Martin Hostettler <martin at neutronstar.dyndns.org>
> + *
> + * 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.
> + *
> + * This program is distributed in the hope that it will be useful, but
> + * WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> + * General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
> + * 02110-1301 USA
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/init.h>
> +#include <linux/platform_device.h>
> +
> +#include <asm/gpio.h>
> +#include <plat/mux.h>
> +#include "mux.h"
> +
> +#include "../../../drivers/media/video/isp/isp.h"
> +#include "../../../drivers/media/video/mt9m032.h"

mt9m032.h should be moved to include/media (the same is true for isp.h as 
well, I'll probably split it and move the part required by board files to 
include/media/omap3isp.h).

> +#include "devices.h"
> +
> +#define EVM_TWL_GPIO_BASE OMAP_MAX_GPIO_LINES
> +#define GPIO98_VID_DEC_RES	98
> +#define nCAM_VD_SEL		157
> +
> +#define MT9M032_I2C_BUS_NUM	2
> +
> +
> +enum omap3evmdc_mux {
> +	MUX_TVP5146,
> +	MUX_CAMERA_SENSOR,
> +	MUX_EXP_CAMERA_SENSOR,
> +};
> +
> +/**
> + * omap3evm_set_mux - Sets mux to enable signal routing to
> + *                           different peripherals present on new EVM
> board + * @mux_id: enum, mux id to enable
> + *
> + * Returns 0 for success or a negative error code
> + */
> +static int omap3evm_set_mux(enum omap3evmdc_mux mux_id)
> +{
> +	/* Set GPIO6 = 1 */
> +	gpio_set_value_cansleep(EVM_TWL_GPIO_BASE + 6, 1);
> +	gpio_set_value_cansleep(EVM_TWL_GPIO_BASE + 2, 0);
> +
> +	switch (mux_id) {
> +	case MUX_TVP5146:
> +		gpio_set_value_cansleep(EVM_TWL_GPIO_BASE + 2, 0);
> +		gpio_set_value(nCAM_VD_SEL, 1);
> +		break;
> +
> +	case MUX_CAMERA_SENSOR:
> +		gpio_set_value_cansleep(EVM_TWL_GPIO_BASE + 2, 0);
> +		gpio_set_value(nCAM_VD_SEL, 0);
> +		break;
> +
> +	case MUX_EXP_CAMERA_SENSOR:
> +		gpio_set_value_cansleep(EVM_TWL_GPIO_BASE + 2, 1);
> +		break;
> +
> +	default:
> +		pr_err("omap3evm-camera: Invalid mux id #%d\n", mux_id);
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +

> +static int __init camera_init(void)
> +{
> +	omap_mux_init_gpio(nCAM_VD_SEL, OMAP_PIN_OUTPUT);
> +	if (gpio_request(nCAM_VD_SEL, "nCAM_VD_SEL") < 0) {
> +		pr_err("omap3evm-camera: Failed to get GPIO nCAM_VD_SEL(%d)\n",
> +		       nCAM_VD_SEL);
> +		goto err;

You can return -EINVAL directly here. This removes the need for the 'err' 
label.

> +	}
> +	if (gpio_direction_output(nCAM_VD_SEL, 1) < 0) {
> +		pr_err("omap3evm-camera: Failed to set GPIO nCAM_VD_SEL(%d)
> direction\n", +		       nCAM_VD_SEL);
> +		goto err_vdsel;
> +	}
> +
> +	if (gpio_request(EVM_TWL_GPIO_BASE + 2, "T2_GPIO2") < 0) {
> +		pr_err("omap3evm-camera: Failed to get GPIO T2_GPIO2(%d)\n",
> +		       EVM_TWL_GPIO_BASE + 2);
> +		goto err_vdsel;
> +	}
> +	if (gpio_direction_output(EVM_TWL_GPIO_BASE + 2, 0) < 0) {
> +		pr_err("omap3evm-camera: Failed to set GPIO T2_GPIO2(%d) direction\n",
> +		       EVM_TWL_GPIO_BASE + 2);
> +		goto err_2;
> +	}
> +
> +	if (gpio_request(EVM_TWL_GPIO_BASE + 8, "nCAM_VD_EN") < 0) {
> +		pr_err("omap3evm-camera: Failed to get GPIO nCAM_VD_EN(%d)\n",
> +		       EVM_TWL_GPIO_BASE + 8);
> +		goto err_2;
> +	}
> +	if (gpio_direction_output(EVM_TWL_GPIO_BASE + 8, 0) < 0) {
> +		pr_err("omap3evm-camera: Failed to set GPIO nCAM_VD_EN(%d) direction\n",
> +		       EVM_TWL_GPIO_BASE + 8);
> +		goto err_8;
> +	}
> +
> +	omap3evm_set_mux(MUX_CAMERA_SENSOR);
> +
> +
> +	return omap3_init_camera(&isp_platform_data);

If this call fails, shouldn't you free the GPIOs ?

> +
> +err_8:
> +	gpio_free(EVM_TWL_GPIO_BASE + 8);
> +err_2:
> +	gpio_free(EVM_TWL_GPIO_BASE + 2);
> +err_vdsel:
> +	gpio_free(nCAM_VD_SEL);
> +err:
> +	return -EINVAL;
> +}
> +
> +device_initcall(camera_init);

If the code is kept in its own file, you should make camera_init non-static 
(and rename it) and call it from the OMAP3 EVM initialization function 
instead.

-- 
Regards,

Laurent Pinchart