| Message ID | 1359325055-5160-2-git-send-email-dev@lynxeye.de |
|---|---|
| State | Changes Requested, archived |
| Headers | show |
On 01/27/2013 03:17 PM, Lucas Stach wrote:
> AC97 controller clock is hardwired to pll_a_out0.
I would like Prashant's/Peter's review here too.
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On 01/27/2013 03:17 PM, Lucas Stach wrote:
> AC97 controller clock is hardwired to pll_a_out0.
One more comment here; don't you need to add this clock into
audio_parents[]?
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Am Montag, den 28.01.2013, 12:15 -0700 schrieb Stephen Warren: > On 01/27/2013 03:17 PM, Lucas Stach wrote: > > AC97 controller clock is hardwired to pll_a_out0. > > One more comment here; don't you need to add this clock into > audio_parents[]? > Yeah it's documented that AC97 can be used as audio_sync_clock, but for one I haven't tested this and also ac97 clock == pll_a_out0, so you can just as well use the pll out in that case. Regards, Lucas -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 01/28/2013 12:25 PM, Lucas Stach wrote: > Am Montag, den 28.01.2013, 12:15 -0700 schrieb Stephen Warren: >> On 01/27/2013 03:17 PM, Lucas Stach wrote: >>> AC97 controller clock is hardwired to pll_a_out0. >> >> One more comment here; don't you need to add this clock into >> audio_parents[]? >> > Yeah it's documented that AC97 can be used as audio_sync_clock, but for > one I haven't tested this I expect there are quite a few of the clock driver table entries that aren't tested. I still think we should add them though, once the clocks they refer to actually exist. > and also ac97 clock == pll_a_out0, so you can > just as well use the pll out in that case. I suspect that "ac97 clock == pll_a_out0" isn't categorically true; it's quite possible that the TRM simply doesn't document the mux register/field for the ac97 clock since the ac97 module is considered deprecated. The diagram at the end of section 5.2.3 "Audio Clocks" certainly implies that all of the i2s*, spdifout, and ac97 clocks have the same structure. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> > > and also ac97 clock == pll_a_out0, so you can > > just as well use the pll out in that case. > > I suspect that "ac97 clock == pll_a_out0" isn't categorically true; it's > quite possible that the TRM simply doesn't document the mux > register/field for the ac97 clock since the ac97 module is considered > deprecated. The diagram at the end of section 5.2.3 "Audio Clocks" > certainly implies that all of the i2s*, spdifout, and ac97 clocks have > the same structure. It indeed does, but I can't find any reference to a mux control register for ac97 in any document... Cheers, Peter. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 01/30/2013 02:35 AM, Peter De Schrijver wrote: >> >>> and also ac97 clock == pll_a_out0, so you can >>> just as well use the pll out in that case. >> >> I suspect that "ac97 clock == pll_a_out0" isn't categorically true; it's >> quite possible that the TRM simply doesn't document the mux >> register/field for the ac97 clock since the ac97 module is considered >> deprecated. The diagram at the end of section 5.2.3 "Audio Clocks" >> certainly implies that all of the i2s*, spdifout, and ac97 clocks have >> the same structure. > > It indeed does, but I can't find any reference to a mux control register for > ac97 in any document... For both these two issues, I'll try and track down the relevant HW engineers or other sources of documentation internally... -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Am Mittwoch, den 30.01.2013, 11:27 -0700 schrieb Stephen Warren: > On 01/30/2013 02:35 AM, Peter De Schrijver wrote: > >> > >>> and also ac97 clock == pll_a_out0, so you can > >>> just as well use the pll out in that case. > >> > >> I suspect that "ac97 clock == pll_a_out0" isn't categorically true; it's > >> quite possible that the TRM simply doesn't document the mux > >> register/field for the ac97 clock since the ac97 module is considered > >> deprecated. The diagram at the end of section 5.2.3 "Audio Clocks" > >> certainly implies that all of the i2s*, spdifout, and ac97 clocks have > >> the same structure. > > > > It indeed does, but I can't find any reference to a mux control register for > > ac97 in any document... > > For both these two issues, I'll try and track down the relevant HW > engineers or other sources of documentation internally... > Ping. I would really like to see those two patches in 3.9, as otherwise Colibri T20 boots up with kernel warnings and a non-functional audio. Regards, Lucas -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 03/21/2013 08:01 AM, Lucas Stach wrote: > Am Mittwoch, den 30.01.2013, 11:27 -0700 schrieb Stephen Warren: >> On 01/30/2013 02:35 AM, Peter De Schrijver wrote: >>>> >>>>> and also ac97 clock == pll_a_out0, so you can >>>>> just as well use the pll out in that case. >>>> >>>> I suspect that "ac97 clock == pll_a_out0" isn't categorically true; it's >>>> quite possible that the TRM simply doesn't document the mux >>>> register/field for the ac97 clock since the ac97 module is considered >>>> deprecated. The diagram at the end of section 5.2.3 "Audio Clocks" >>>> certainly implies that all of the i2s*, spdifout, and ac97 clocks have >>>> the same structure. >>> >>> It indeed does, but I can't find any reference to a mux control register for >>> ac97 in any document... >> >> For both these two issues, I'll try and track down the relevant HW >> engineers or other sources of documentation internally... >> > Ping. > I would really like to see those two patches in 3.9, as otherwise > Colibri T20 boots up with kernel warnings and a non-functional audio. Sorry, I seem to have forgotten about this, and it looks like I wasn't able to get any kind of answer from HW. I expect it's far too late to get this into 3.9. I guess we can go ahead and add the clock without actually resolving these issues; I don't think their resolution would affect the device tree at all, so there should be no compatibility issues to worry about. I suggest reposting to Mike Turqette (clock maintainer) to see if he'll take it as a fix for 3.9, or ack it so I can. If not, if he can ack it, I'll take it for 3.10 along with the Tegra clock driver changes. -- To unsubscribe from this list: send the line "unsubscribe linux-tegra" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/clk/tegra/clk-tegra20.c b/drivers/clk/tegra/clk-tegra20.c index f08cffc..1be8c23 100644 --- a/drivers/clk/tegra/clk-tegra20.c +++ b/drivers/clk/tegra/clk-tegra20.c @@ -894,6 +894,14 @@ static void __init tegra20_periph_clk_init(void) struct clk *clk; int i; + /* ac97 */ + clk = tegra_clk_register_periph_gate("ac97", "pll_a_out0", + TEGRA_PERIPH_ON_APB, + clk_base, 0, 3, &periph_l_regs, + periph_clk_enb_refcnt); + clk_register_clkdev(clk, NULL, "tegra20-ac97"); + clks[ac97] = clk; + /* apbdma */ clk = tegra_clk_register_periph_gate("apbdma", "pclk", 0, clk_base, 0, 34, &periph_h_regs,
AC97 controller clock is hardwired to pll_a_out0. Signed-off-by: Lucas Stach <dev@lynxeye.de> --- drivers/clk/tegra/clk-tegra20.c | 8 ++++++++ 1 file changed, 8 insertions(+)