From mboxrd@z Thu Jan 1 00:00:00 1970 From: Delio Brignoli Subject: Re: Minimal support for dm814x Date: Tue, 10 Nov 2015 11:23:35 +0100 Message-ID: <7933071D-84FD-4A85-8CD0-CC504CE1D9D1@audioscience.com> References: <4999BB3D-4BB5-4F7C-96D7-FB687725CDCC@audioscience.com> <20151109150602.GR3199@atomide.com> Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Matthijs van Duin Cc: Tony Lindgren , "linux-omap@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" List-Id: linux-omap@vger.kernel.org On 10 Nov 2015, at 09:50, Matthijs van Duin wro= te: > On 9 November 2015 at 16:06, Tony Lindgren wrote: >> The PLL support is still missing, so it relies on the bootloader >> configured PLL values for now. I'm hoping to post PLL support patches ov= er >> next few weeks and then we can have that and more devices working for v4= .5. > = > Ah, yes, configuring a DPLL-LJ is fun.. figuring out how to write the > desired ratio as M/(M2*(1+N)) while simultaneously satisfying all > constraints on M, N, M2, refclk, and dco. :-) Yes, indeed. We have the additional requirement of being able to adjust the= frequency (by a relatively small amount) without loss of lock. Recalculati= ng the DCO mode and M,N,M2 from scratch each time based on the target frequ= ency, like was done in the 2.6.37 based tree from TI was not acceptable, so= we try to change m2 first to see if we can reach the target frequency and = fall back to recalculate parameters from scratch if that fails. BTW, are you aware of section 2.1.2 of =93TMS320DM814x DaVinci Digital Medi= a Processors Silicon Revisions 3.0, 2.1=94? Regards =97 Delio From mboxrd@z Thu Jan 1 00:00:00 1970 From: dbrignoli@audioscience.com (Delio Brignoli) Date: Tue, 10 Nov 2015 11:23:35 +0100 Subject: Minimal support for dm814x In-Reply-To: References: <4999BB3D-4BB5-4F7C-96D7-FB687725CDCC@audioscience.com> <20151109150602.GR3199@atomide.com> Message-ID: <7933071D-84FD-4A85-8CD0-CC504CE1D9D1@audioscience.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 10 Nov 2015, at 09:50, Matthijs van Duin wrote: > On 9 November 2015 at 16:06, Tony Lindgren wrote: >> The PLL support is still missing, so it relies on the bootloader >> configured PLL values for now. I'm hoping to post PLL support patches over >> next few weeks and then we can have that and more devices working for v4.5. > > Ah, yes, configuring a DPLL-LJ is fun.. figuring out how to write the > desired ratio as M/(M2*(1+N)) while simultaneously satisfying all > constraints on M, N, M2, refclk, and dco. :-) Yes, indeed. We have the additional requirement of being able to adjust the frequency (by a relatively small amount) without loss of lock. Recalculating the DCO mode and M,N,M2 from scratch each time based on the target frequency, like was done in the 2.6.37 based tree from TI was not acceptable, so we try to change m2 first to see if we can reach the target frequency and fall back to recalculate parameters from scratch if that fails. BTW, are you aware of section 2.1.2 of ?TMS320DM814x DaVinci Digital Media Processors Silicon Revisions 3.0, 2.1?? Regards ? Delio