> -----Original Message----- > From: Enric Balletbò i Serra [mailto:eballe...@gmail.com] > Sent: Friday, November 19, 2010 6:43 PM > To: Premi, Sanjeev > Cc: u-boot@lists.denx.de; Steve Sakoman > Subject: Re: [U-Boot] AM/DM37X How to configure registers to > get 1000MHz
[snip]...[snip] > >> > >> I'm thinking in two scenarios : > >> > >> 1. For OMAP35X there are devices that support 600MHz as > max frequency > >> but others supports 720MHz, I want to set by default 600MHz and if > >> device supports 720MHz change to this frequency. > > > > [sp] You can look at one of my patches on linux kernel to > identify the > > device capability for 600/720MHz. > > I''ll do, thanks > > > > >> 2. For AM/DM37X, maybe I'm wrong, but the default frequency for > >> AM/DM37X is set to 600MHz, Like OMAP35X i want to set default to > >> 800MHz and i device supports change to 1000MHz. > > > > [sp] The device comes up at 600MHz for now, but there is no > limitation > > on device to go all the way to 1GHz. > > > >> > >> Which is the better way to do this ? > > > > [sp] So, you are looking for common mechanism to go to > highest supported > > frequency. Right? > > Yes, I think should be interesting for all OMAP35/AM/DM37 a > mechanism like this. [sp] I am stuck is a critical activity for next few days; would be able to work on this only next week. However, if you could start on it, I have quick thought process here: 1) Have a function that returns max supported freq for each device. - Function for OMAP35x can internally check the capability bit - While the one for AM37x would return 1GHz. 2) There is a mapping table for freq. and corresponding M, N, M2 values that can be used to pick select the right values. 3) Such a table exists in ASM; I have an intent to make it more readable in C - but always goes low in priority. 4) Another twist to 2) above can be use of env variable that gets pref. e.g. 37x support 1GHz; but you wantto still boot at 800MHz for some reason; then setting env var would make the function return 800 instead of 1000. ~sanjeev > > > > >> > >> Thanks in advance, > >> Enric > >> > >> > > >> > ~sanjeev > >> > > >> >> > >> >> Thanks in advance, > >> >> Enric > >> >> _______________________________________________ > >> >> U-Boot mailing list > >> >> U-Boot@lists.denx.de > >> >> http://lists.denx.de/mailman/listinfo/u-boot > >> >> > >> > _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de http://lists.denx.de/mailman/listinfo/u-boot