[PATCH 0/4] mmc: pwrseq: post_ios power sequence
From: Romain Perier
Date: Wed Mar 01 2017 - 10:04:55 EST
Some devices, like WiFi chipsets AP6335 require a specific power-up
sequence ordering before being used. You must enable the vqmmc power supply
and wait until it reaches its minimum voltage, gate the clock and wait
at least two cycles and then assert the reset line.
See DS 1/
Currently, there is no generic manner for doing this with pwrseq_simple.
This set of patches proposes an approach to support this use case.
It is related to the old patch 2/
1. http://www.t-firefly.com/download/firefly-rk3288/hardware/AP6335%20datasheet_V1.3_02102014.pdf
2. http://lists.infradead.org/pipermail/linux-arm-kernel/2017-March/490681.html
Romain Perier (4):
mmc: core: Add post_ios_power_on callback for power sequences
mmc: pwrseq-simple: Add optional op. for post_ios_power_on callback
mmc: pwrseq_simple: Add an optional pre-power-on-delay
arm: dts: rockchip: Enable post_ios_power_on and pre-power-on-delay-ms
.../devicetree/bindings/mmc/mmc-pwrseq-simple.txt | 2 ++
arch/arm/boot/dts/rk3288-rock2-square.dts | 2 ++
drivers/mmc/core/core.c | 1 +
drivers/mmc/core/pwrseq.c | 8 ++++++++
drivers/mmc/core/pwrseq.h | 2 ++
drivers/mmc/core/pwrseq_simple.c | 21 ++++++++++++++++++++-
6 files changed, 35 insertions(+), 1 deletion(-)
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2.9.3