On Tue, Apr 14, 2009 at 10:57:32AM +0200, Guennadi Liakhovetski wrote:
> 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.hauer@xxxxxxxxxxxxxx>
> > > ---
> > > 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.
So how do we proceed? Add init/exit functions for the bus?
Sascha
>
> 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
>
--
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 |
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