On 09/07/18 17:38, Aapo Vienamo wrote:
> From: Peter De Schrijver <pdeschrijver@xxxxxxxxxx>
>
> Move this to a separate file so it can be used to calculate the sdmmc
> clock dividers.
Sorry for not commenting sooner, but what is the motivation for moving
this to its own file? I don't see why we need to do this in order to use
elsewhere. Furthermore, the original file is quite aptly named 'clk-divider.c'
and now we have a div71.c which seems quite specific.
> Signed-off-by: Peter De-Schrijver <pdeschrijver@xxxxxxxxxx>
> Signed-off-by: Aapo Vienamo <avienamo@xxxxxxxxxx>
> Acked-by: Peter De Schrijver <pdeschrijver@xxxxxxxxxx>
> ---
> drivers/clk/tegra/Makefile | 1 +
> drivers/clk/tegra/clk-divider.c | 30 +++++-----------------------
> drivers/clk/tegra/clk.h | 3 +++
> drivers/clk/tegra/div71.c | 43 +++++++++++++++++++++++++++++++++++++++++
> 4 files changed, 52 insertions(+), 25 deletions(-)
> create mode 100644 drivers/clk/tegra/div71.c
>
> diff --git a/drivers/clk/tegra/Makefile b/drivers/clk/tegra/Makefile
> index b716923..6d4f563 100644
> --- a/drivers/clk/tegra/Makefile
> +++ b/drivers/clk/tegra/Makefile
> @@ -24,3 +24,4 @@ obj-$(CONFIG_ARCH_TEGRA_132_SOC) += clk-tegra124.o
> obj-y += cvb.o
> obj-$(CONFIG_ARCH_TEGRA_210_SOC) += clk-tegra210.o
> obj-$(CONFIG_CLK_TEGRA_BPMP) += clk-bpmp.o
> +obj-y += div71.o
> diff --git a/drivers/clk/tegra/clk-divider.c b/drivers/clk/tegra/clk-divider.c
> index 16e0aee..ad87858 100644
> --- a/drivers/clk/tegra/clk-divider.c
> +++ b/drivers/clk/tegra/clk-divider.c
> @@ -32,35 +32,15 @@
> static int get_div(struct tegra_clk_frac_div *divider, unsigned long rate,
> unsigned long parent_rate)
> {
> - u64 divider_ux1 = parent_rate;
> - u8 flags = divider->flags;
> - int mul;
> -
> - if (!rate)
> - return 0;
> -
> - mul = get_mul(divider);
> -
> - if (!(flags & TEGRA_DIVIDER_INT))
> - divider_ux1 *= mul;
> -
> - if (flags & TEGRA_DIVIDER_ROUND_UP)
> - divider_ux1 += rate - 1;
> -
> - do_div(divider_ux1, rate);
> -
> - if (flags & TEGRA_DIVIDER_INT)
> - divider_ux1 *= mul;
> + int div;
>
> - divider_ux1 -= mul;
> + div = div71_get(rate, parent_rate, divider->width, divider->frac_width,
> + divider->flags);
>
> - if ((s64)divider_ux1 < 0)
> + if (div < 0)
> return 0;
>
> - if (divider_ux1 > get_max_div(divider))
> - return get_max_div(divider);
> -
> - return divider_ux1;
> + return div;
> }
>
> static unsigned long clk_frac_div_recalc_rate(struct clk_hw *hw,
> diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
> index e3b9c22..149cc70 100644
> --- a/drivers/clk/tegra/clk.h
> +++ b/drivers/clk/tegra/clk.h
> @@ -812,6 +812,9 @@ extern tegra_clk_apply_init_table_func tegra_clk_apply_init_table;
> int tegra_pll_wait_for_lock(struct tegra_clk_pll *pll);
> u16 tegra_pll_get_fixed_mdiv(struct clk_hw *hw, unsigned long input_rate);
> int tegra_pll_p_div_to_hw(struct tegra_clk_pll *pll, u8 p_div);
> +int div71_get(unsigned long rate, unsigned parent_rate, u8 width,
> + u8 frac_width, u8 flags);
> +
>
> /* Combined read fence with delay */
> #define fence_udelay(delay, reg) \
> diff --git a/drivers/clk/tegra/div71.c b/drivers/clk/tegra/div71.c
> new file mode 100644
> index 0000000..1eecc84
> --- /dev/null
> +++ b/drivers/clk/tegra/div71.c
> @@ -0,0 +1,43 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.
> + */
> +
> +#include <asm/div64.h>
> +
> +#include "clk.h"
> +
> +#define div_mask(w) ((1 << (w)) - 1)
> +
> +int div71_get(unsigned long rate, unsigned parent_rate, u8 width,
> + u8 frac_width, u8 flags)
> +{
> + u64 divider_ux1 = parent_rate;
> + int mul;
> +
> + if (!rate)
> + return 0;
> +
> + mul = 1 << frac_width;
> +
> + if (!(flags & TEGRA_DIVIDER_INT))
> + divider_ux1 *= mul;
> +
> + if (flags & TEGRA_DIVIDER_ROUND_UP)
> + divider_ux1 += rate - 1;
> +
> + do_div(divider_ux1, rate);
> +
> + if (flags & TEGRA_DIVIDER_INT)
> + divider_ux1 *= mul;
> +
> + if (divider_ux1 < mul)
> + return 0;
> +
> + divider_ux1 -= mul;
> +
> + if (divider_ux1 > div_mask(width))
> + return div_mask(width);
> +
> + return divider_ux1;
> +}
I don't see anything in the above that makes this 7.1? It seems that the
fractional width is being passed meaning it could be m.n unless I am missing
something.
Cheers
Jon
--
nvpublic
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