Hi Sakari, On Wed, Jan 11, 2012 at 5:03 PM, Sakari Ailus <sakari.ailus@xxxxxx> wrote: > Hi Paul, > > On Wed, Jan 11, 2012 at 07:11:58AM -0700, Paul Walmsley wrote: >> On Sun, 8 Jan 2012, Sakari Ailus wrote: >> >> > Hi Tony and Paul, >> > >> > On Wed, Dec 14, 2011 at 05:14:16PM +0200, Sakari Ailus wrote: >> > > The register is used to configure the behaviour of the CSI-2 and CCP-2 >> > > receivers. This register is available only in OMAP3630. >> > > >> > > The original patch was submitted by Vimarsh Zutshi. >> > > >> > > Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxx> >> > > --- >> > > arch/arm/mach-omap2/control.h | 1 + >> > > 1 files changed, 1 insertions(+), 0 deletions(-) >> > > >> > > diff --git a/arch/arm/mach-omap2/control.h b/arch/arm/mach-omap2/control.h >> > > index d4ef75d..6a26a0d 100644 >> > > --- a/arch/arm/mach-omap2/control.h >> > > +++ b/arch/arm/mach-omap2/control.h >> > > @@ -183,6 +183,7 @@ >> > > #define OMAP3630_CONTROL_FUSE_OPP120_VDD1 (OMAP2_CONTROL_GENERAL + 0x0120) >> > > #define OMAP3630_CONTROL_FUSE_OPP50_VDD2 (OMAP2_CONTROL_GENERAL + 0x0128) >> > > #define OMAP3630_CONTROL_FUSE_OPP100_VDD2 (OMAP2_CONTROL_GENERAL + 0x012C) >> > > +#define OMAP3630_CONTROL_CAMERA_PHY_CTRL (OMAP2_CONTROL_GENERAL + 0x02f0) >> > >> > I assume this patch hasn't gone anywhere yet which might be good. While the >> > definition of this register would appear to belong to this file, it is being >> > included from the OMAP 3 ISP driver, which only uses it if it's running on >> > the 3630. The problem is that control.h isn't apparently intended to be >> > included except locally and I didn't find a suitable file under include/mach >> > to put this definition either. Currently this file is being included by the >> > ISP driver with an explicit path. >> > >> > Do you have an insight how this could be handled better? >> >> We've been trying to ensure that register accesses to/from a given IP >> block only occur in a driver for that IP block. So under that principle, >> any System Control Module accesses should go into a System Control Module >> driver. Then that SCM driver should export (via EXPORT_SYMBOL) a >> higher-level interface to whatever code uses it. The idea is that this >> interface would remain stable no matter what underlying SoC was in use. >> >> Only thing is, we don't yet have a SCM driver. Historically, since the >> SCM is tightly coupled with the underlying SoC, when we've needed to do >> something like this in the past, we've added code to >> arch/arm/mach-omap2/control.c. But that's not really workable now. >> >> Do you know if this register, or something like it, is present on later >> OMAPs? Also, which bitfields are you planning to use? > > I don't believe it exists on other OMAPs --- possibly on 3730 but the CSI-2 > receiver is not officially supported on it. The register does not exist on > the 3430, at least not under the same name --- a reason for not existing > could be that the 3430 only has one CSI-2 receiver. The 4430 doesn't seem to > have it either, at least not under that name. In 4430/4460, there's CONTROL_CAMERA_RX (physical address: 0x4A100608), but it's not exactly compatible. There are some similar bit fields, but in different bit offsets: 3630 has these: - [3:2] R_CONTROL_CAMERA1_PHY_CAMMODE - [1:0] R_CONTROL_CAMERA2_PHY_CAMMODE And 4430/4460 has these fields: - [20:19] CAMERARX_CSI22_CAMMODE - [17:16] CAMERARX_CSI21_CAMMODE Both of them used to configure each CSIPHY module, to use it on: - 0x0: D-PHY mode (for CSI-2 cameras) - 0x1: Data/Strobe mode (for CCP2 mode) - 0x2: Data/Clock mode (for either CCP2 or CSI1 mode) - 0x3: Reserved(4430), or GPI/Parallel (4460/3630) mode But other OMAP4 bitfields are completely unexisting on OMAP3 (3630), as there some slight IP changes on the way the Camera CSIPHY is controlled. Regards, Sergio > > I think the solution to conditionally access it in the ISP driver would be, > albeit not pretty, a workable one: the driver is unlikely to be used on > other platforms and this is a single register accessed in a single location. > I'm of course open for better options. > > Cc Sergio. > > -- > Sakari Ailus > e-mail: sakari.ailus@xxxxxx jabber/XMPP/Gmail: sailus@xxxxxxxxxxxxxx -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
