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authorPeter De Schrijver <pdeschrijver@nvidia.com>2018-07-12 14:53:00 +0300
committerStephen Boyd <sboyd@kernel.org>2018-07-25 23:43:34 +0300
commitcb3ac5947afb3bb7e2f89c1b59f61dcf3e115fe1 (patch)
tree7111e58446fef9a299069b9104c9e32a09732a11 /drivers/clk
parent0cbb61a313979b53d6b2dc838a92f07471440708 (diff)
downloadlinux-cb3ac5947afb3bb7e2f89c1b59f61dcf3e115fe1.tar.xz
clk: tegra: Refactor fractional divider calculation
Move this to a separate file so it can be used to calculate the sdmmc clock dividers. Signed-off-by: Peter De-Schrijver <pdeschrijver@nvidia.com> Signed-off-by: Aapo Vienamo <avienamo@nvidia.com> Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com> Acked-by: Jon Hunter <jonathanh@nvidia.com> Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Diffstat (limited to 'drivers/clk')
-rw-r--r--drivers/clk/tegra/Makefile1
-rw-r--r--drivers/clk/tegra/clk-divider.c30
-rw-r--r--drivers/clk/tegra/clk-utils.c43
-rw-r--r--drivers/clk/tegra/clk.h3
4 files changed, 52 insertions, 25 deletions
diff --git a/drivers/clk/tegra/Makefile b/drivers/clk/tegra/Makefile
index b71692391bd6..c77d072eb333 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 += clk-utils.o
diff --git a/drivers/clk/tegra/clk-divider.c b/drivers/clk/tegra/clk-divider.c
index 16e0aee14773..8f175ff62f73 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 = div_frac_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-utils.c b/drivers/clk/tegra/clk-utils.c
new file mode 100644
index 000000000000..1a5daae4e501
--- /dev/null
+++ b/drivers/clk/tegra/clk-utils.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 div_frac_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;
+}
diff --git a/drivers/clk/tegra/clk.h b/drivers/clk/tegra/clk.h
index e3b9c22ad8b2..c733841aa6db 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 div_frac_get(unsigned long rate, unsigned parent_rate, u8 width,
+ u8 frac_width, u8 flags);
+
/* Combined read fence with delay */
#define fence_udelay(delay, reg) \