From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tom Rini Date: Wed, 23 May 2012 09:55:40 -0700 Subject: [U-Boot] [PATCH 5/7] OMAP5: EMIF: Add support for DDR3 device In-Reply-To: References: <1337681007-22709-1-git-send-email-lokeshvutla@ti.com> <1337681007-22709-6-git-send-email-lokeshvutla@ti.com> <20120522144151.GA21740@bill-the-cat> <20120522151813.GB21740@bill-the-cat> <4FBBB332.2040409@ti.com> Message-ID: <4FBD168C.4080403@ti.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On 05/23/2012 05:22 AM, R, Sricharan wrote: > Hi Tom, >>> >>> ah, this is what is there on OMAP5. >>> 3 for DDR3 >>> 4 for LPDDR2-S4, >>> 5 for LPDDR2-S2 >> >> >> 4/5 are listed as reserved here :( http://www.ti.com/lit/pdf/spruh73 >> >> >>> Atleast DDR3 encoding is same. So we can differentiate bw DDR3 and 2 >>> in same way. >>> Is the reset value set correctly on am335x according to the device >>> connected? >> >> >> I'll have to do some checking as the code doesn't check that today. >> > The reset value reflects the connected device correctly for lpddr2 and ddr3. > Is that the same case in am33xx platforms ? Yes, it's 3 on DDR3 and 2 on (non-LP) DDR2. I spent some time yesterday starting on splitting up emif-common (am33xx does not have DMM) and making am33xx link at least with the common code. My idea is to add a few more defines and make that part of do_sdram_init be: if (!in_sdram) { switch(reg_sdram_type) { #ifdef CONFIG_EMIF4_DDR2 case 2: ddr2_init(); break; #ifdef CONFIG_EMFI4_DDR3 case 3: ddr3_init(); break; #endif #ifdef CONFIG_EMIF4_LPDDR2 case 4: case 5: lpddr2_init(); break; #endif default: panic("Unsupported DDR type connected to EMIF4"); } } And move lpddr2_init to emif4-lpddr2.c, and so forth. My experimenting yesterday lead me to conclude that EMIF_MOD_ID_REGISTER behaves as is documented for am33xx on omap4/5 so what we're doing should be feasible. I'm going to try and locally make the ddr3 patches work on the am33xx DDR3 board as a way to prove that out and if it works, and we're fine with what I've laid out above, start working towards that layout. -- Tom