WARNING: This macro do not assume the values for K0DB4, KxDB2, KxFREE,
K1RUN, K2RUN and APD bits of CONFIG_SYS_MDREFR_VAL as it was
done early on many pxa platforms. All pxa developers that plan
to use this macro should check the validity of their MDREFR values.
v1:
* strict following to section 6.4.10 of Intel PXA27xx Developer's Manual.
* use r7 to store CONFIG_SYS_MDREFR_VAL as r6 is used in pxa_wait_ticks.
v2:
* rename pxa_mem_setup macro to pxa2xx_mem_setup
* setting of MDREFR[K1RUN] and MDREFR[K2RUN] bits may be optional
* skip certain configuration steps if SDRAM is not present/configured
* improve/fix comments
PS: This patch should not go upstream at this point as it require more work.
Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevets...@gmail.com>
---
arch/arm/include/asm/arch-pxa/macro.h | 78 +++++++++++++++++++++-----------
board/vpac270/lowlevel_init.S | 2 +-
2 files changed, 52 insertions(+), 28 deletions(-)
diff --git a/arch/arm/include/asm/arch-pxa/macro.h
b/arch/arm/include/asm/arch-pxa/macro.h
index 035a57e..468482a 100644
--- a/arch/arm/include/asm/arch-pxa/macro.h
+++ b/arch/arm/include/asm/arch-pxa/macro.h
@@ -102,11 +102,15 @@
/*
* This macro sets up the Memory controller of the PXA2xx CPU
*
- * Clobbered regs: r3, r4, r5
+ * Clobbered regs: r3, r4, r5, r6, r7
+ *
+ * See section 6.4.10 of Intel PXA2xx Processor Developer's Manual
+ *
http://www.marvell.com/products/processors/applications/pxa_family/pxa_27x_dev_man.pdf
*/
-.macro pxa_mem_setup
+.macro pxa2xx_mem_setup
/* This comes handy when setting MDREFR */
ldr r3, =MEMC_BASE
+ ldr r7, =CONFIG_SYS_MDREFR_VAL
/*
* 1) Initialize Asynchronous static memory controller
@@ -149,51 +153,66 @@
*/
/*
- * Before accessing MDREFR we need a valid DRI field, so we set
- * this to power on defaults + DRI field.
+ * Before accessing MDREFR we need a valid DRI field.
+ * Also we must properly configure MDREFR[K0DB2] and MDREFR[K0DB4].
+ * Optionaly we can set MDREFR[KxFREE] bits.
+ * So we set MDREFR to power on defaults + (DRI, K0DB2, K0DB4, KxFREE)
+ * fields from the config.
+ *
+ * WARNING: K0DB2 and K0DB4 bits are usually set, while KxFREE bits
+ * are usually unset.
*/
ldr r5, [r3, #MDREFR_OFFSET]
- bic r5, r5, #0x0ff
- bic r5, r5, #0xf00 /* MDREFR user config with zeroed DRI */
-
- ldr r4, =CONFIG_SYS_MDREFR_VAL
- mov r6, r4
- lsl r4, #20
- lsr r4, #20 /* Get a valid DRI field */
-
- orr r5, r5, r4 /* MDREFR user config with correct DRI */
+ ldr r4, =( 0xFFF | MDREFR_K0DB4 | MDREFR_K0DB2 | \
+ MDREFR_K0FREE | MDREFR_K1FREE | MDREFR_K2FREE )
+ bic r5, r5, r4 /* clear DRI, K0DB2, K0DB4, KxFREE fields */
+ and r4, r7, r4
+ orr r5, r5, r4 /* use custom DRI, K0DB2, K0DB4, KxFREE */
orr r5, #MDREFR_K0RUN
orr r5, #MDREFR_SLFRSH
bic r5, #MDREFR_APD
- bic r5, #MDREFR_E1PIN
+
+ /* enable them later, if SDRAM is present */
+ bic r5, #( MDREFR_E1PIN | MDREFR_K1RUN | MDREFR_K2RUN | \
+ MDREFR_K1DB2 | MDREFR_K2DB2 )
str r5, [r3, #MDREFR_OFFSET]
- ldr r4, [r3, #MDREFR_OFFSET]
+ ldr r5, [r3, #MDREFR_OFFSET]
/*
* 5) Initialize Synchronous Static Memory (Flash/Peripherals)
*/
- /* Initialize SXCNFG register. Assert the enable bits.
- *
- * Write SXMRS to cause an MRS command to all enabled banks of
- * synchronous static memory. Note that SXLCR need not be written
- * at this time.
+ /* Initialize SXCNFG register to enable synchronous flash memory.
+ * While the synchronous flash banks are being configured, the SDRAM
+ * banks must be disabled and MDREFR[APD] must be de-asserted.
*/
write32rb (MEMC_BASE + SXCNFG_OFFSET), CONFIG_SYS_SXCNFG_VAL
/*
- * 6) Initialize SDRAM
+ * 6) Initialize SDRAM,
+ * If SDRAM present, then MDREFR[K1RUN] and/or MDREFR[K2RUN] bits
+ * must be set. Also we must properly configure MDREFR[K1DB2] and
+ * MDREFR[K2DB2] in this case.
+ *
+ * WARNING: K1DB2 and K2DB2 bits are usually set if SDRAM present
*/
+ and r4, r7, #( MDREFR_K1RUN | MDREFR_K2RUN | \
+ MDREFR_K1DB2 | MDREFR_K2DB2 )
+ ldr r6, [r3, #MDREFR_OFFSET]
+ orr r6, r6, r4
+ str r6, [r3, #MDREFR_OFFSET]
+ ldr r6, [r3, #MDREFR_OFFSET]
+
bic r6, #MDREFR_SLFRSH
str r6, [r3, #MDREFR_OFFSET]
- ldr r4, [r3, #MDREFR_OFFSET]
+ ldr r6, [r3, #MDREFR_OFFSET]
orr r6, #MDREFR_E1PIN
str r6, [r3, #MDREFR_OFFSET]
- ldr r4, [r3, #MDREFR_OFFSET]
+ ldr r6, [r3, #MDREFR_OFFSET]
/*
* 7) Write MDCNFG with MDCNFG:DEx deasserted (set to 0), to configure
@@ -226,7 +245,7 @@
.endr
/*
- * 9) Write MDCNFG with enable bits asserted (MDCNFG:DEx set to 1).
+ * 9) Set custom MDCNFG[DEx] bits to enable required SDRAM partitions
*/
ldr r5, =CONFIG_SYS_MDCNFG_VAL
@@ -238,7 +257,10 @@
ldr r4, [r3, #MDCNFG_OFFSET]
/*
- * 10) Write MDMRS.
+ * 10) Write to MDMRS register to trigger an MRS command to
+ * all enabled banks of SDRAM. For each SDRAM partition pair
+ * that has one or both partitions enabled, this forces a pass
+ * through the MRS state and a return to NOP.
*/
ldr r4, =CONFIG_SYS_MDMRS_VAL
@@ -246,11 +268,13 @@
ldr r4, [r3, #MDMRS_OFFSET]
/*
- * 11) Enable APD
+ * 11) Optionaly enable auto-power-down by setting MDREFR[APD]
+ *
+ * WARNING: APD bit is usually set.
*/
ldr r4, [r3, #MDREFR_OFFSET]
- and r6, r6, #MDREFR_APD
+ and r6, r7, #MDREFR_APD
orr r4, r4, r6
str r4, [r3, #MDREFR_OFFSET]
ldr r4, [r3, #MDREFR_OFFSET]
diff --git a/board/vpac270/lowlevel_init.S b/board/vpac270/lowlevel_init.S
index ec0d12c..a327ebd 100644
--- a/board/vpac270/lowlevel_init.S
+++ b/board/vpac270/lowlevel_init.S
@@ -32,7 +32,7 @@
lowlevel_init:
pxa_gpio_setup
pxa_wait_ticks 0x8000
- pxa_mem_setup
+ pxa2xx_mem_setup
pxa_wakeup
pxa_intr_setup
pxa_clock_setup
--
1.7.1
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