Re: [PATCH v4 5/7] clk: axi-clkgen: Respect ZYNQMP PFD/VCO frequency limits
From: Moritz Fischer <mdf@kernel.org>
Date: 2020-09-29 15:30:45
Also in:
linux-fpga, lkml
Hi Alexandru, On Tue, Sep 29, 2020 at 05:44:15PM +0300, Alexandru Ardelean wrote:
From: Mathias Tausen <redacted> Since axi-clkgen is now supported on ZYNQMP, make sure the max/min frequencies of the PFD and VCO are respected. Signed-off-by: Mathias Tausen <redacted> Signed-off-by: Alexandru Ardelean <redacted>
This patch still does not cover the PCIe Zynq plugged into ZynqMP linux machine case.
quoted hunk ↗ jump to hunk
--- drivers/clk/clk-axi-clkgen.c | 9 +++++++++ 1 file changed, 9 insertions(+)diff --git a/drivers/clk/clk-axi-clkgen.c b/drivers/clk/clk-axi-clkgen.c index 4342b7735590..2319bb1c5c08 100644 --- a/drivers/clk/clk-axi-clkgen.c +++ b/drivers/clk/clk-axi-clkgen.c@@ -108,12 +108,21 @@ static uint32_t axi_clkgen_lookup_lock(unsigned int m) return 0x1f1f00fa; } +#ifdef ARCH_ZYNQMP +static const struct axi_clkgen_limits axi_clkgen_default_limits = { + .fpfd_min = 10000, + .fpfd_max = 450000, + .fvco_min = 800000, + .fvco_max = 1600000, +}; +#else static const struct axi_clkgen_limits axi_clkgen_default_limits = { .fpfd_min = 10000, .fpfd_max = 300000, .fvco_min = 600000, .fvco_max = 1200000, }; +#endif
I still don't understand this. You have a way to determine which fabric
you are looking at with the FPGA info. Why not:
[..] axi_clkgen_zynqmp_default_limits = {
};
[..] axi_clkgen_default_limits = {
};
Set them based on what you read back, i.e. determine which fabric you
are looking at *per clock gen* and use that info, rather than making a
compile time decision to support only one of them.
Generally speaking #ifdef $ARCH should be a last resort solution.static void axi_clkgen_calc_params(const struct axi_clkgen_limits *limits, unsigned long fin, unsigned long fout, -- 2.17.1
Cheers, Moritz