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| author | Albert ARIBAUD <albert.u.boot@aribaud.net> | 2013-05-11 20:24:28 (GMT) |
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| committer | Albert ARIBAUD <albert.u.boot@aribaud.net> | 2013-05-11 20:24:28 (GMT) |
| commit | cac423a730d3506154744485af1bbc1cd3a1e6a8 (patch) | |
| tree | 358b627972d9125de573c623f33e2da789f1de51 /doc | |
| parent | c1b43ac7699640c8086bd73faa798bc9722d32c9 (diff) | |
| parent | 47c6ea076eb51e624f8744d93db5cd70b97dc25d (diff) | |
| download | u-boot-cac423a730d3506154744485af1bbc1cd3a1e6a8.tar.xz | |
Merge branch 'u-boot-ti/master' into 'u-boot-arm/master'
Diffstat (limited to 'doc')
| -rw-r--r-- | doc/README.omap-reset-time | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/doc/README.omap-reset-time b/doc/README.omap-reset-time new file mode 100644 index 0000000..0c974ba --- /dev/null +++ b/doc/README.omap-reset-time @@ -0,0 +1,20 @@ +README on how reset time on OMAPs should be calculated + +CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC: +Most OMAPs' provide a way to specify the time for +which the reset should be held low while the voltages +and Oscillator outputs stabilize. + +This time is mostly board and PMIC dependent. Hence the +boards are expected to specify a pre-computed time +using the above option, (the details on how to compute +the value are given below) without which a default time +as specified by CONFIG_DEFAULT_OMAP_RESET_TIME_MAX_USEC +is used. + +The value for CONFIG_OMAP_PLATFORM_RESET_TIME_MAX_USEC +can be computed using a summation of the below 3 parameters +-1- Time taken by the Osciallator to stop and restart +-2- PMIC OTP time +-3- Voltage ramp time, which can be derived using the +PMIC slew rate and value of voltage ramp needed. |