On Thu, 9 Apr 2009, Guennadi Liakhovetski wrote:
> Hi Sascha,
>
> something, that skipped both of us:
...and one more:
> On Thu, 12 Mar 2009, Sascha Hauer wrote:
>
> > Some Phytec cameras have a I2C GPIO expander which allows it to
> > switch between different sensor bus widths. This was previously
> > handled in the camera driver. Since handling of this switch
> > varies on several boards the cameras are used on, the board
> > support seems a better place to handle the switch
> >
> > Signed-off-by: Sascha Hauer <s.ha...@pengutronix.de>
> > ---
> > arch/arm/mach-pxa/pcm990-baseboard.c | 53
> > ++++++++++++++++++++++++++++------
> > 1 files changed, 44 insertions(+), 9 deletions(-)
> >
> > diff --git a/arch/arm/mach-pxa/pcm990-baseboard.c
> > b/arch/arm/mach-pxa/pcm990-baseboard.c
> > index 34841c7..fd8f786 100644
> > --- a/arch/arm/mach-pxa/pcm990-baseboard.c
> > +++ b/arch/arm/mach-pxa/pcm990-baseboard.c
> > @@ -381,14 +381,49 @@ static struct pca953x_platform_data pca9536_data = {
> > .gpio_base = NR_BUILTIN_GPIO + 1,
> > };
> >
> > -static struct soc_camera_link iclink[] = {
> > - {
> > - .bus_id = 0, /* Must match with the camera ID above */
> > - .gpio = NR_BUILTIN_GPIO + 1,
> > - }, {
> > - .bus_id = 0, /* Must match with the camera ID above */
> > - .gpio = -ENXIO,
> > +static int gpio_bus_switch;
> > +
> > +static int pcm990_camera_set_bus_param(struct soc_camera_link *link,
> > + unsigned long flags)
> > +{
> > + if (gpio_bus_switch <= 0) {
> > + if (flags == SOCAM_DATAWIDTH_10)
> > + return 0;
> > + else
> > + return -EINVAL;
> > + }
> > +
> > + if (flags & SOCAM_DATAWIDTH_8)
> > + gpio_set_value(gpio_bus_switch, 1);
> > + else
> > + gpio_set_value(gpio_bus_switch, 0);
> > +
> > + return 0;
> > +}
> > +
> > +static unsigned long pcm990_camera_query_bus_param(struct soc_camera_link
> > *link)
> > +{
> > + int ret;
> > +
> > + if (!gpio_bus_switch) {
> > + ret = gpio_request(NR_BUILTIN_GPIO + 1, "camera");
>
> There's no gpio_free() now... So, for example, you cannot unload the
> extender driver any more, unloading i2c adapter driver (i2c-pxa) produces
> ugly stuff like
>
> pca953x 0-0041: gpiochip_remove() failed, -16
>
> So, we either have to request and free the GPIO in each query / set, or we
> need an explicit .free_bus() call in soc_camera_link. None of the two
> really pleases me, but maybe the latter is slightly less ugly, what do you
> think?
>
> Thanks
> Guennadi
>
> > + if (!ret) {
> > + gpio_bus_switch = NR_BUILTIN_GPIO + 1;
> > + gpio_direction_output(gpio_bus_switch, 0);
> > + } else
> > + gpio_bus_switch = -EINVAL;
> > }
If you first do not load pca953x and try to start capture, thus calling
pcm990_camera_query_bus_param(), gpio_request() will fail and you get
gpio_bus_switch < 0. Then if you load pca953x it doesn't help any more -
by testing for "if (!gpio_bus_switch)" you do not retry after the first
error.
Thanks
Guennadi
> > +
> > + if (gpio_bus_switch > 0)
> > + return SOCAM_DATAWIDTH_8 | SOCAM_DATAWIDTH_10;
> > + else
> > + return SOCAM_DATAWIDTH_10;
> > +}
> > +
> > +static struct soc_camera_link iclink = {
> > + .bus_id = 0, /* Must match with the camera ID above */
> > + .query_bus_param = pcm990_camera_query_bus_param,
> > + .set_bus_param = pcm990_camera_set_bus_param,
> > };
> >
> > /* Board I2C devices. */
> > @@ -399,10 +434,10 @@ static struct i2c_board_info __initdata
> > pcm990_i2c_devices[] = {
> > .platform_data = &pca9536_data,
> > }, {
> > I2C_BOARD_INFO("mt9v022", 0x48),
> > - .platform_data = &iclink[0], /* With extender */
> > + .platform_data = &iclink, /* With extender */
> > }, {
> > I2C_BOARD_INFO("mt9m001", 0x5d),
> > - .platform_data = &iclink[0], /* With extender */
> > + .platform_data = &iclink, /* With extender */
> > },
> > };
> > #endif /* CONFIG_VIDEO_PXA27x ||CONFIG_VIDEO_PXA27x_MODULE */
> > --
> > 1.5.6.5
> >
> > --
> > Pengutronix e.K. | |
> > Industrial Linux Solutions | http://www.pengutronix.de/ |
> > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
> > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
> >
>
> ---
> Guennadi Liakhovetski, Ph.D.
> Freelance Open-Source Software Developer
>
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
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