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authorAneesh V <aneesh@ti.com>2011-07-21 09:10:15 -0400
committerU-Boot <uboot@aari01-12.(none)>2011-08-03 12:49:19 +0200
commit1e463866f5b26ec7d7579f2d6ec348402d8c96b4 (patch)
treeb76bb1c157b94fe358ffd0ff6ba55c92d2eeb88f /include
parent095aea293b70114dda0d958788a8acc15e3cd665 (diff)
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omap4: automatic sdram detection
Identify SDRAM devices connected to EMIF automatically: LPDDR2 devices have some Mode Registers that provide details about the device such as the type, density, bus width etc. EMIF has the capability to read these registers. If there are no devices connected to a given chip-select reading mode registers will return junk values. After reading as many such registers as possible and matching with expected ranges of values the driver can identify if there is a device connected to the respective CS. If we identify that a device is connected the values read give us complete details about the device. This along with the base AC timings specified by JESD209-2 allows us to do a complete automatic initialization of SDRAM that works on all boards. Please note that the default AC timings specified by JESD209-2 will be safe for all devices but not necessarily optimal. However, for the Elpida devices used on Panda and SDP the default timings are both safe and optimal. Signed-off-by: Aneesh V <aneesh@ti.com> Signed-off-by: Sandeep Paulraj <s-paulraj@ti.com>
Diffstat (limited to 'include')
-rw-r--r--include/configs/omap4_panda.h1
-rw-r--r--include/configs/omap4_sdp4430.h1
2 files changed, 2 insertions, 0 deletions
diff --git a/include/configs/omap4_panda.h b/include/configs/omap4_panda.h
index 9f82ef4..a8dd861 100644
--- a/include/configs/omap4_panda.h
+++ b/include/configs/omap4_panda.h
@@ -239,6 +239,7 @@
/* Defines for SDRAM init */
#ifndef CONFIG_SYS_EMIF_PRECALCULATED_TIMING_REGS
+#define CONFIG_SYS_AUTOMATIC_SDRAM_DETECTION
#define CONFIG_SYS_DEFAULT_LPDDR2_TIMINGS
#endif
diff --git a/include/configs/omap4_sdp4430.h b/include/configs/omap4_sdp4430.h
index 6df1c3d..534f89a 100644
--- a/include/configs/omap4_sdp4430.h
+++ b/include/configs/omap4_sdp4430.h
@@ -245,6 +245,7 @@
/* Defines for SDRAM init */
#ifndef CONFIG_SYS_EMIF_PRECALCULATED_TIMING_REGS
+#define CONFIG_SYS_AUTOMATIC_SDRAM_DETECTION
#define CONFIG_SYS_DEFAULT_LPDDR2_TIMINGS
#endif