Subject: [PATCH v3] arm: omap3evm: Add support for an MT9M032 based camera board.

From: [email-masked] (martin at neutronstar.dyndns.org)
Date: Wed, 14 Dec 2011 19:14:01 +0100

On Wed, Dec 14, 2011 at 11:31:35AM +0200, Igor Grinberg wrote:
> Hi Martin,
> 
> On 12/14/11 03:25, Martin Hostettler wrote:
> > Adds board support for an MT9M032 based camera to omap3evm.
> > 
> > Signed-off-by: Martin Hostettler <[email-masked]>
> > ---
> >  arch/arm/mach-omap2/Makefile                |    3 +-
> >  arch/arm/mach-omap2/board-omap3evm-camera.c |  155 +++++++++++++++++++++++++++
> >  arch/arm/mach-omap2/board-omap3evm.c        |    4 +
> >  3 files changed, 161 insertions(+), 1 deletions(-)
> >  create mode 100644 arch/arm/mach-omap2/board-omap3evm-camera.c
> > 
> > Changes in V3
> >  * Added missing copyright and attribution.
> >  * switched to gpio_request_array for gpio init.
> >  * removed device_initcall and added call to omap3_evm_camera_init into omap3_evm_init
> > 
> > Changes in V2:
> >  * ported to current mainline
> >  * Style fixes
> >  * Fix error handling
> > 
> > diff --git a/arch/arm/mach-omap2/Makefile b/arch/arm/mach-omap2/Makefile
> > index b009f17..6045789 100644
> > --- a/arch/arm/mach-omap2/Makefile
> > +++ b/arch/arm/mach-omap2/Makefile
> > @@ -196,7 +196,8 @@ obj-$(CONFIG_MACH_OMAP3530_LV_SOM)      += board-omap3logic.o
> >  obj-$(CONFIG_MACH_OMAP3_TORPEDO)        += board-omap3logic.o
> >  obj-$(CONFIG_MACH_ENCORE)		+= board-omap3encore.o
> >  obj-$(CONFIG_MACH_OVERO)		+= board-overo.o
> > -obj-$(CONFIG_MACH_OMAP3EVM)		+= board-omap3evm.o
> > +obj-$(CONFIG_MACH_OMAP3EVM)		+= board-omap3evm.o \
> > +					   board-omap3evm-camera.o
> >  obj-$(CONFIG_MACH_OMAP3_PANDORA)	+= board-omap3pandora.o
> >  obj-$(CONFIG_MACH_OMAP_3430SDP)		+= board-3430sdp.o
> >  obj-$(CONFIG_MACH_NOKIA_N8X0)		+= board-n8x0.o
> > 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..bffd5b8
> > --- /dev/null
> > +++ b/arch/arm/mach-omap2/board-omap3evm-camera.c
> > @@ -0,0 +1,155 @@
> > +/*
> > + * Copyright (C) 2011 Texas Instruments Inc
> > + * Copyright (C) 2010-2011 Lund Engineering
> > + * Contact: Gil Lund <[email-masked]>
> > + * Authors:
> > + *    Vaibhav Hiremath <[email-masked]>
> > + *    Martin Hostettler <[email-masked]>
> > + *
> > + * Board intregration for a MT9M032 camera connected to IMAGE_CONN and I2C Bus 2
> > + *
> > + * 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 <linux/gpio.h>
> > +#include <plat/mux.h>
> > +#include "mux.h"
> > +
> > +#include "../../../drivers/media/video/omap3isp/isp.h"
> 
> Laurent,
> In one of the previous reviews, you stated:
> "I'll probably split it and move the part required by board files to 
> include/media/omap3isp.h".
> Is there any progress on that?
> 
> > +#include "media/mt9m032.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;
> > +}
> 
> I don't really care about that, but I don't see any mux
> being set in the above function so the name and comments
> are misleading.

There's are video muxes on this board that's controlled by various
gpios. It's not a mux in the omap chip if you've expected to see that.

As this is an evaluation board it has a bunch of video connectors that 
the user can choose from for different input devices.

> 
> > +
> > +static struct mt9m032_platform_data mt9m032_platform_data = {
> > +	.ext_clock = 13500000,
> > +	.pll_pre_div = 6,
> > +	.pll_mul = 120,
> > +	.pll_out_div = 5,
> > +	.invert_pixclock = 1,
> > +};
> > +
> > +static struct i2c_board_info camera_i2c_devices[] = {
> > +	{
> > +		I2C_BOARD_INFO(MT9M032_NAME, MT9M032_I2C_ADDR),
> > +		.platform_data = &mt9m032_platform_data,
> > +	},
> > +};
> > +
> > +static struct isp_subdev_i2c_board_info camera_i2c_subdevs[] = {
> > +	{
> > +		.board_info = &camera_i2c_devices[0],
> > +		.i2c_adapter_id = MT9M032_I2C_BUS_NUM,
> > +	},
> > +	{},
> > +};
> > +
> > +static struct isp_v4l2_subdevs_group camera_subdevs[] = {
> > +	{
> > +		.subdevs = camera_i2c_subdevs,
> > +		.interface = ISP_INTERFACE_PARALLEL,
> > +		.bus = {
> > +			.parallel = {
> > +				.data_lane_shift = 1,
> > +				.clk_pol = 0,
> > +				.bridge = ISPCTRL_PAR_BRIDGE_DISABLE,
> > +			}
> > +		},
> > +	},
> > +	{},
> > +};
> > +
> > +static struct isp_platform_data isp_platform_data = {
> > +	.subdevs = camera_subdevs,
> > +};
> > +
> > +
> > +static struct gpio setup_gpios[] = {
> > +	{ nCAM_VD_SEL,           GPIOF_OUT_INIT_HIGH, "nCAM_VD_SEL" },
> > +	{ EVM_TWL_GPIO_BASE + 2, GPIOF_OUT_INIT_LOW,  "T2_GPIO2" },
> > +	{ EVM_TWL_GPIO_BASE + 8, GPIOF_OUT_INIT_LOW, "nCAM_VD_EN" },
> > +};
> > +
> > +
> > +int __init omap3_evm_camera_init(void)
> > +{
> > +	int ret = -EINVAL;
> 
> No need to initialize the variable, as it is done three line below.

Yes, i'll fix that.

> 
> > +
> > +	omap_mux_init_gpio(nCAM_VD_SEL, OMAP_PIN_OUTPUT);
> > +	ret = gpio_request_array(setup_gpios, ARRAY_SIZE(setup_gpios));
> > +	if (ret < 0) {
> > +		pr_err("omap3evm-camera: Failed to setup camera signal routing.\n");
> > +		return ret;
> > +	}
> 
> It looks like both above calls (gpio_request and mux_init)
> can be moved to omap3evm_set_mux() function (or a renamed version of it),
> so all the GPIO stuff will be close to each other instead of requesting
> in one place and playing with values in another...

I'd like to keep the one time setup and the theoretically run time switchable
parts seperate. It doesn't complicate the code and if a brave soul wants to
connect different camera modules and switch between them it's a more reviewable
patch from here.

> 
> > +	omap3evm_set_mux(MUX_CAMERA_SENSOR);
> 
> So the plan is to add support for the 3 types,
> but hard code to only one?
> Can't this be runtime detected somehow?

The mux code came from out of tree drivers. I did want to keep enough
information so someone extending this board code for other setups doesn't have a
hard time. I can't think of an reliable way to runtime detect what video source
a specific use case would want. Ideally someone who needs one of the other
video sources should add a more generic solution here. 

> 
> > +	ret = omap3_init_camera(&isp_platform_data);
> > +	if (ret < 0) {
> > +		gpio_free_array(setup_gpios, ARRAY_SIZE(setup_gpios));
> > +		return ret;
> > +	}
> > +	return 0;
> > +}
> > diff --git a/arch/arm/mach-omap2/board-omap3evm.c b/arch/arm/mach-omap2/board-omap3evm.c
> > index ec00b2e..1b50539 100644
> > --- a/arch/arm/mach-omap2/board-omap3evm.c
> > +++ b/arch/arm/mach-omap2/board-omap3evm.c
> > @@ -617,6 +617,8 @@ static struct gpio omap3_evm_ehci_gpios[] __initdata = {
> >  	{ OMAP3_EVM_EHCI_SELECT, GPIOF_OUT_INIT_LOW,   "select EHCI port" },
> >  };
> >  
> > +int omap3_evm_camera_init(void);
> > +
> >  static void __init omap3_evm_init(void)
> >  {
> >  	omap3_evm_get_revision();
> > @@ -672,6 +674,8 @@ static void __init omap3_evm_init(void)
> >  		pr_err("error setting wl12xx data\n");
> >  	platform_device_register(&omap3evm_wlan_regulator);
> >  #endif
> > +
> > +	omap3_evm_camera_init();
> >  }
> >  
> >  MACHINE_START(OMAP3EVM, "OMAP3 EVM")
> 

 - Martin

> -- 
> Regards,
> Igor.