On Thu, 2011-01-06 at 15:10 +0530, ext Semwal, Sumit wrote:
> Hi Tomi,
>
> On Wed, Jan 5, 2011 at 9:05 PM, Tomi Valkeinen <tomi.valkeinen@xxxxxxxxx> wrote:
> > On Mon, 2011-01-03 at 18:21 +0530, ext Guruswamy Senthilvadivu wrote:
> >> From: Senthilvadivu Guruswamy <svadivu@xxxxxx>
> >>
> >> clks are moved to dss platform driver. clk_get/put APIs use dss device instead
> >> of core platform device. So the device name is changed from omap_display to
> >> omap_dss in 2420, 2430, 3xxx clock database files. Now teh core driver
> >> "omap_display" only takes care of panel registration with the custom bus.
> >> dss driver would take care of the clocks needed by DISPC, RFBI, DSI, VENC.
> >>
> >> TODO: The clock content would be adapted to omap_hwmod in a seperate series.
> >>
> >> Signed-off-by: Senthilvadivu Guruswamy <svadivu@xxxxxx>
> >
> > <snip>
> >
> >> @@ -508,14 +192,7 @@ static int omap_dss_probe(struct platform_device *pdev)
> >> dss_init_overlay_managers(pdev);
> >> dss_init_overlays(pdev);
> >>
> >> - r = dss_get_clocks();
> >> - if (r)
> >> - goto err_clocks;
> >> -
> >> - dss_clk_enable_all_no_ctx();
> >> -
> >> - core.ctx_id = dss_get_ctx_id();
> >> - DSSDBG("initial ctx id %u\n", core.ctx_id);
> >> + dss_clk_enable(DSS_CLK_ICK | DSS_CLK_FCK1 | DSS_CLK_54M);
> >>
> >> #ifdef CONFIG_FB_OMAP_BOOTLOADER_INIT
> >> /* DISPC_CONTROL */
> >> @@ -589,7 +266,7 @@ static int omap_dss_probe(struct platform_device *pdev)
> >> pdata->default_device = dssdev;
> >> }
> >>
> >> - dss_clk_disable_all();
> >> + dss_clk_disable(DSS_CLK_ICK | DSS_CLK_FCK1 | DSS_CLK_54M);
> >
> > Why are the calls dss_clk_enable_all_no_ctx() and dss_clk_disable_all()
> > changed?
> This came as an after-effect of moving all clk related stuff to dss.c;
> I think the idea is that all the new DSS IP platform drivers should
> use only the exposed clock mgmt APIs [dss_clk_enable() /
> dss_clk_disable()].
Ah, right.
> However, you are right; all the required clocks might not be getting
> enabled / disabled as required.
> I can (re)create the static dss_clk_disable_all() /
> dss_clk_enable_all_no_ctx() locally inside core.c - do you think
> that's ok, or should I export these functions too from dss.c?
Well... I think all the xxx_init() functions should enable the clocks
they require, so in that sense enabling the clocks is not needed at all.
But there's the (hackish) code for CONFIG_FB_OMAP_BOOTLOADER_INIT, which
requires normal dss clocks. Also if each xxx_init() call enables and
disables the clocks, and dss_probe doesn't keep the clocks enabled, then
we would get a ctx save/restore after every init, which would not be
nice.
So I think enabling just ICK and FCK1 would be enough, to get
CONFIG_FB_OMAP_BOOTLOADER_INIT work and to prevent ctx save/restore.
Perhaps there should be a comment above the dss_clk_enable, like "keep
clocks enabled to prevent context saves/restores during init".
Tomi
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