Re: [PATCH 05/10] clk: qcom: add Global Clock controller (GCC) driver for IPQ5332 SoC

[Kathiravan Thirumoorthy]

On 1/26/2023 2:24 AM, Stephen Boyd wrote:
> Quoting Kathiravan Thirumoorthy (2023-01-25 02:45:15)
> > diff --git a/drivers/clk/qcom/gcc-ipq5332.c b/drivers/clk/qcom/gcc-ipq5332.c
> > new file mode 100644
> > index 000000000000..8351096a4d32
> > --- /dev/null
> > +++ b/drivers/clk/qcom/gcc-ipq5332.c
> > @@ -0,0 +1,3954 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright (c) 2022-2023 Qualcomm Innovation Center, Inc. All rights reserved.
> > + */
> > +
> > +#include <linux/clk-provider.h>
> > +#include <linux/module.h>
> > +#include <linux/of_device.h>
> > +#include <linux/regmap.h>
> [...]
> > +
> > +static const struct freq_tbl ftbl_gcc_pcnoc_bfdcd_clk_src[] = {
> > +       F(24000000, P_XO, 1, 0, 0),
> > +       F(50000000, P_GPLL0_OUT_MAIN, 16, 0, 0),
> > +       F(100000000, P_GPLL0_OUT_MAIN, 8, 0, 0),
> > +       { }
> > +};
> > +
> > +static struct clk_rcg2 gcc_pcnoc_bfdcd_clk_src = {
> > +       .cmd_rcgr = 0x31004,
> > +       .mnd_width = 0,
> > +       .hid_width = 5,
> > +       .parent_map = gcc_parent_map_0,
> > +       .freq_tbl = ftbl_gcc_pcnoc_bfdcd_clk_src,
> > +       .clkr.hw.init = &(const struct clk_init_data){
> > +               .name = "gcc_pcnoc_bfdcd_clk_src",
> > +               .parent_data = gcc_parent_data_0,
> > +               .num_parents = ARRAY_SIZE(gcc_parent_data_0),
> > +               .ops = &clk_rcg2_ops,
> > +               .flags = CLK_IS_CRITICAL,
> Why not just turn these clks on in probe and never register them with
> the framework? That saves some memory for clks that there is no desire
> to control from linux. This is an RCG, so in theory the frequency can
> change, but does it really? Usually bus clks are controlled by the
> interconnect driver.

Thanks Stephen for reviewing the patch. I will look into this and make 
changes appropriately in V2.