forked from Minki/linux
e24a04c44c
The BuckWise DC-DC convertors in WM831x devices support switching to a second output voltage using the logic level on one of the device pins. This is intended to allow rapid voltage switching for uses like cpufreq, replacing the I2C or SPI write used to configure the voltage of the regulator with a much faster GPIO status change. This is implemented by keeping the DVS voltage configured as the maximum voltage permitted for the regulator. If a request is made for the maximum voltage then the GPIO is used to switch to the DVS voltage, otherwise the normal ON voltage is updated and used. This follows the idiom used by most cpufreq drivers, which drop the minimum voltage as the core frequency is dropped but use a constant maximum - raising the voltage should normally be fast, but lowering it may be slower. Configuration of the DVS MFP on the device should be done externally, for example via OTP. Support is present in the hardware for monitoring the status of the transition using a second GPIO. This is not currently implemented but platform data is provided for it - the driver currently assumes that the device will be configured to transition immediately - but platform data is provided to reduce merge issues once it is. Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Acked-by: Samuel Ortiz <sameo@linux.intel.com> Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk> |
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| acpi | ||
| asm-generic | ||
| crypto | ||
| drm | ||
| keys | ||
| linux | ||
| math-emu | ||
| media | ||
| mtd | ||
| net | ||
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| rdma | ||
| rxrpc | ||
| scsi | ||
| sound | ||
| trace | ||
| video | ||
| xen | ||
| Kbuild | ||