Re: [PATCH 4/4] spi: bcm-mspi: Add support to set serial baud clock rate

From: Mark Brown
Date: Mon Apr 06 2015 - 05:47:07 EST


On Sat, Apr 04, 2015 at 12:12:59PM -0700, Florian Fainelli wrote:
> Le 02/04/2015 12:23, Jonathan Richardson a écrit :

> > + /* Calculate SPBR if clock-frequency provided. */
> > + if (of_property_read_u32(dev->of_node, "clock-frequency",
> > + &desired_rate) >= 0) {
> > + u32 spbr = clk_get_rate(data->clk) / (2 * desired_rate);

> Usually, specifying a "clock-frequency" property is done when there is
> no clock provider available, yet we take this code path only if we could
> find a "mspi_clk" which sounds a litle weird.

> Once there is a proper "mspi_clk" clock, I would make it mandatory for
> the clock provider to be able to provide the rate as well?

As far as I can tell it's already mandatory if the property is present -
it's taking the clock presented to the block and then using an internal
divider to bring that down to the desired rate.

We are missing error handling though.

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