To speed-up linux kernel loading, switch the PXA cpu to the
maximum allowed frequency (520 MHz). This improves the load
time from several seconds to less than a second from the
MTD.
Signed-off-by: Robert Jarzmik <robert.jarzmik@xxxxxxx>
---
arch/arm/boards/mioa701/board.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/arch/arm/boards/mioa701/board.c b/arch/arm/boards/mioa701/board.c
index 14c8110..ab5a493 100644
--- a/arch/arm/boards/mioa701/board.c
+++ b/arch/arm/boards/mioa701/board.c
@@ -261,8 +261,17 @@ static int mioa701_coredevice_init(void)
/* route pins */
pxa2xx_mfp_config(ARRAY_AND_SIZE(mioa701_pin_config));
- CCCR = CCCR_A | 0x20110;
- cclk = 0x02;
+ /*
+ * Put the board in superspeed (520 MHz) to speed-up logo/OS loading.
+ * This requires to command the Maxim 1586 to upgrade core voltage to
+ * 1.475 V, on the power I2C bus (device 0x14).
+ */
+ CCCR = CCCR_A | 0x20290;
+ PCFR = PCFR_GPR_EN | PCFR_FVC | PCFR_DC_EN | PCFR_PI2C_EN | PCFR_OPDE;
+ PCMD(0) = PCMD_LC | 0x1f;
+ PVCR = 0x14;
+
+ cclk = 0x0b;
asm volatile("mcr p14, 0, %0, c6, c0, 0 @ set CCLK"
: : "r" (cclk) : "cc");
--
1.7.10
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