Re: [PATCH v3 06/11] clk: tegra: remove EMC to MC clock mux in Tegra114

Svyatoslav Ryhel
2025-11-13T14:29:21Z

чт, 13 лист. 2025 р. о 07:05 Mikko Perttunen <mperttunen@nvidia.com> пише:
>
> On Monday, September 15, 2025 5:01 PM Svyatoslav Ryhel wrote:
> > Configure EMC without mux for correct EMC driver support.
>
> Rather than just 'removing EMC to MC clock mux in Tegra114', I would say this patch removes current emc and emc_mux clocks and replaces them with the proper EMC clock implementation. I would edit the commit subject and commit message along those lines.
>

Noted

> >
> > Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
> > ---
> > drivers/clk/tegra/clk-tegra114.c | 48 ++++++++++++++++++++++----------
> > 1 file changed, 33 insertions(+), 15 deletions(-)
> >
> > diff --git a/drivers/clk/tegra/clk-tegra114.c b/drivers/clk/tegra/clk-tegra114.c
> > index 8bde72aa5e68..6b3a140772c2 100644
> > --- a/drivers/clk/tegra/clk-tegra114.c
> > +++ b/drivers/clk/tegra/clk-tegra114.c
> > @@ -622,10 +622,6 @@ static const char *mux_plld_out0_plld2_out0[] = {
> > };
> > #define mux_plld_out0_plld2_out0_idx NULL
> >
> > -static const char *mux_pllmcp_clkm[] = {
> > - "pll_m_out0", "pll_c_out0", "pll_p_out0", "clk_m", "pll_m_ud",
> > -};
> > -
> > static const struct clk_div_table pll_re_div_table[] = {
> > { .val = 0, .div = 1 },
> > { .val = 1, .div = 2 },
> > @@ -672,7 +668,6 @@ static struct tegra_clk tegra114_clks[tegra_clk_max] __initdata = {
> > [tegra_clk_csi] = { .dt_id = TEGRA114_CLK_CSI, .present = true },
> > [tegra_clk_i2c2] = { .dt_id = TEGRA114_CLK_I2C2, .present = true },
> > [tegra_clk_uartc] = { .dt_id = TEGRA114_CLK_UARTC, .present = true },
> > - [tegra_clk_emc] = { .dt_id = TEGRA114_CLK_EMC, .present = true },
> > [tegra_clk_usb2] = { .dt_id = TEGRA114_CLK_USB2, .present = true },
> > [tegra_clk_usb3] = { .dt_id = TEGRA114_CLK_USB3, .present = true },
> > [tegra_clk_vde_8] = { .dt_id = TEGRA114_CLK_VDE, .present = true },
> > @@ -1048,14 +1043,7 @@ static __init void tegra114_periph_clk_init(void __iomem *clk_base,
> > 0, 82, periph_clk_enb_refcnt);
> > clks[TEGRA114_CLK_DSIB] = clk;
> >
> > - /* emc mux */
> > - clk = clk_register_mux(NULL, "emc_mux", mux_pllmcp_clkm,
> > - ARRAY_SIZE(mux_pllmcp_clkm),
> > - CLK_SET_RATE_NO_REPARENT,
> > - clk_base + CLK_SOURCE_EMC,
> > - 29, 3, 0, &emc_lock);
> > -
> > - clk = tegra_clk_register_mc("mc", "emc_mux", clk_base + CLK_SOURCE_EMC,
> > + clk = tegra_clk_register_mc("mc", "emc", clk_base + CLK_SOURCE_EMC,
> > &emc_lock);
> > clks[TEGRA114_CLK_MC] = clk;
> >
> > @@ -1321,6 +1309,28 @@ static int tegra114_reset_deassert(unsigned long id)
> > return 0;
> > }
> >
> > +#ifdef CONFIG_TEGRA124_CLK_EMC
> > +static struct clk *tegra114_clk_src_onecell_get(struct of_phandle_args *clkspec,
> > + void *data)
> > +{
> > + struct clk_hw *hw;
> > + struct clk *clk;
> > +
> > + clk = of_clk_src_onecell_get(clkspec, data);
> > + if (IS_ERR(clk))
> > + return clk;
> > +
> > + hw = __clk_get_hw(clk);
> > +
> > + if (clkspec->args[0] == TEGRA114_CLK_EMC) {
> > + if (!tegra124_clk_emc_driver_available(hw))
> > + return ERR_PTR(-EPROBE_DEFER);
> > + }
> > +
> > + return clk;
> > +}
> > +#endif
> > +
> > static void __init tegra114_clock_init(struct device_node *np)
> > {
> > struct device_node *node;
> > @@ -1362,16 +1372,24 @@ static void __init tegra114_clock_init(struct device_node *np)
> > tegra_audio_clk_init(clk_base, pmc_base, tegra114_clks,
> > tegra114_audio_plls,
> > ARRAY_SIZE(tegra114_audio_plls), 24000000);
> > +
> > + tegra_clk_apply_init_table = tegra114_clock_apply_init_table;
> > +
>
> Is there any particular reason for moving this here? If not, omitting the change would simplify the patch a bit.
>

IIRC, I tried to align with Tegra124 EMC clk driver, I will try to
drop this change and check if all works as expected.

> > tegra_super_clk_gen4_init(clk_base, pmc_base, tegra114_clks,
> > &pll_x_params);
> >
> > tegra_init_special_resets(1, tegra114_reset_assert,
> > tegra114_reset_deassert);
> >
> > +#ifdef CONFIG_TEGRA124_CLK_EMC
> > + tegra_add_of_provider(np, tegra114_clk_src_onecell_get);
> > + clks[TEGRA114_CLK_EMC] = tegra124_clk_register_emc(clk_base, np,
> > + &emc_lock);
> > +#else
> > tegra_add_of_provider(np, of_clk_src_onecell_get);
> > - tegra_register_devclks(devclks, ARRAY_SIZE(devclks));
> > +#endif
>
> tegra124_clk_register_emc and tegra124_clk_emc_driver_available have stub implementations when CONFIG_TEGRA124_CLK_EMC is not enabled, so it would be cleaner to just call them always.
>

Yes, I will adjust this in v4. Thank you.

> >
> > - tegra_clk_apply_init_table = tegra114_clock_apply_init_table;
> > + tegra_register_devclks(devclks, ARRAY_SIZE(devclks));
> >
> > tegra_cpu_car_ops = &tegra114_cpu_car_ops;
> > }
> >
>
>
>
>