Hi Mark, On 01/09/2023 11:19 AM, Mark Brown wrote: > On Mon, Jan 09, 2023 at 12:06:13AM -0800, William Zhang wrote: >>> On Fri, Jan 6, 2023 at 9:27 PM William Zhang wrote: > >>> Keeping the clock on or not would affect all devices unless you have a >>> per device clock you can gate, so making this a per device flag >>> doesn't make sense. > >> This applies only to each chip select. There is only one device under each >> chip select. So won't impact any other devices under other cs. > > I don't understand how this would work - usually a SPI controller has a > single set of clock, MOSI and MISO lines with the only per device thing > being the chip select. If the clock line is used by all devices then it > must be kept on for all of them if it's to be kept on for one of them. > This setting is set per spi message for particular chip select of the device when starting the message through bcm63xx_hsspi_set_clk function and restore to default(clock gating) when message is done through bcm63xx_hsspi_restore_clk_gate.