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authorMichael Heimpold <mhei@heimpold.de>2015-11-15 22:47:12 +0100
committerStefano Babic <sbabic@denx.de>2015-12-01 16:05:24 +0100
commita6b1e25fc6f9ad3a392526414acb1c3c36eccd0f (patch)
treeb16844dc7c582b5a7a0a598288b5e23ead251f68 /arch/arm/cpu
parent90447ef03cc7c2b59e9c1e0e8b5afba969c30f99 (diff)
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ARM: mxs: fix VDDD brownout setting
At the moment, the desired brownout is at 1.0V. However, this setting cannot be realized by hardware since we have only 3 bits to represent the voltage difference from the target value. Target value is 1500 mV, brownout target is 1000 mV, voltage steps are 25 mV. Register content calculation: (1500 [mV] - 1000 [mV]) / 25 [mV] = 20 (decimal) = 0x14 Register takes only 3 bits, that is 0x4. But 0x4 * 25 [mV] = 100 [mV], that means that actual brownout level is 1500 [mV] - 100 [mV] = 1.4 V. Minimum possible BO level is 1500 [mV] - 0x7 * 25 [mV] = 1315 [mV]. So lets use this value as desired BO value (which is also the same as FSL bootlets use). Signed-off-by: Michael Heimpold <mhei@heimpold.de> Cc: Marek Vasut <marex@denx.de> Cc: Otavio Salvador <otavio@ossystems.com.br> Cc: Fabio Estevam <fabio.estevam@freescale.com> Acked-by: Marek Vasut <marex@denx.de>
Diffstat (limited to 'arch/arm/cpu')
-rw-r--r--arch/arm/cpu/arm926ejs/mxs/spl_power_init.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
index 42f3df2..1972de8 100644
--- a/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
+++ b/arch/arm/cpu/arm926ejs/mxs/spl_power_init.c
@@ -1221,8 +1221,8 @@ void mxs_power_init(void)
debug("SPL: Setting VDDIO to 3V3 (brownout @ 3v15)\n");
mxs_power_set_vddx(&mxs_vddio_cfg, 3300, 3150);
- debug("SPL: Setting VDDD to 1V5 (brownout @ 1v0)\n");
- mxs_power_set_vddx(&mxs_vddd_cfg, 1500, 1000);
+ debug("SPL: Setting VDDD to 1V5 (brownout @ 1v315)\n");
+ mxs_power_set_vddx(&mxs_vddd_cfg, 1500, 1315);
#ifdef CONFIG_MX23
debug("SPL: Setting mx23 VDDMEM to 2V5 (brownout @ 1v7)\n");
mxs_power_set_vddx(&mxs_vddmem_cfg, 2500, 1700);