[U-Boot] [PATCH] ARM: omap3_logic.c: Optimize DDR timings based on OMAP35 or 36/37

Adam Ford aford173 at gmail.com
Sun Oct 7 14:20:45 UTC 2018


The default timings are assumming an OMAP36 / AM37 / DM37, but
the OMAP35 controller is a bit slower, so DDR may operate out of
spec when under stress.  This patch checks the processor type and
sets the DDR timings according to processor type.

Fixes: 5ad4212ce0d5 ("ARM: DTS: Add Logic PD OMAP35/DM37 SOM-LV
and OMAP35 Torpedo")

Signed-off-by: Adam Ford <aford173 at gmail.com>

diff --git a/board/logicpd/omap3som/omap3logic.c b/board/logicpd/omap3som/omap3logic.c
index 4507b1ed99..0b827355a8 100644
--- a/board/logicpd/omap3som/omap3logic.c
+++ b/board/logicpd/omap3som/omap3logic.c
@@ -89,11 +89,21 @@ int spl_start_uboot(void)
 void get_board_mem_timings(struct board_sdrc_timings *timings)
 {
 	timings->mr = MICRON_V_MR_165;
-	/* 256MB DDR */
-	timings->mcfg = MICRON_V_MCFG_200(256 << 20);
-	timings->ctrla = MICRON_V_ACTIMA_200;
-	timings->ctrlb = MICRON_V_ACTIMB_200;
-	timings->rfr_ctrl = SDP_3430_SDRC_RFR_CTRL_200MHz;
+
+	if (get_cpu_family() == CPU_OMAP36XX) {
+		/* 200 MHz works for OMAP36/DM37 */
+		/* 256MB DDR */
+		timings->mcfg = MICRON_V_MCFG_200(256 << 20);
+		timings->ctrla = MICRON_V_ACTIMA_200;
+		timings->ctrlb = MICRON_V_ACTIMB_200;
+		timings->rfr_ctrl = SDP_3430_SDRC_RFR_CTRL_200MHz;
+	} else {
+		/* 165 MHz works for OMAP35 */
+		timings->mcfg = MICRON_V_MCFG_165(256 << 20);
+		timings->ctrla = MICRON_V_ACTIMA_165;
+		timings->ctrlb = MICRON_V_ACTIMB_165;
+		timings->rfr_ctrl = SDP_3430_SDRC_RFR_CTRL_165MHz;
+	}
 }
 
 #define GPMC_NAND_COMMAND_0 (OMAP34XX_GPMC_BASE + 0x7c)
-- 
2.17.1



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