From 23b04c84e201e82c1929144a2ce1442bd64e77f3 Mon Sep 17 00:00:00 2001 From: Geert Uytterhoeven Date: Thu, 1 Apr 2021 15:01:35 +0200 Subject: [PATCH] clk: renesas: div6: Simplify src mask handling Simplify the handling of the register bits to select the parent clock, by storing a bitmask instead of separate shift and width values. Signed-off-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/5f05a5110d222ce5a113e683fe2aa726f4100b73.1617281699.git.geert+renesas@glider.be --- drivers/clk/renesas/clk-div6.c | 31 +++++++++++-------------------- 1 file changed, 11 insertions(+), 20 deletions(-) diff --git a/drivers/clk/renesas/clk-div6.c b/drivers/clk/renesas/clk-div6.c index a3c4fbe..2920bec 100644 --- a/drivers/clk/renesas/clk-div6.c +++ b/drivers/clk/renesas/clk-div6.c @@ -28,8 +28,7 @@ * @hw: handle between common and hardware-specific interfaces * @reg: IO-remapped register * @div: divisor value (1-64) - * @src_shift: Shift to access the register bits to select the parent clock - * @src_width: Number of register bits to select the parent clock (may be 0) + * @src_mask: Bitmask covering the register bits to select the parent clock * @nb: Notifier block to save/restore clock state for system resume * @parents: Array to map from valid parent clocks indices to hardware indices */ @@ -37,8 +36,7 @@ struct div6_clock { struct clk_hw hw; void __iomem *reg; unsigned int div; - u32 src_shift; - u32 src_width; + u32 src_mask; struct notifier_block nb; u8 parents[]; }; @@ -133,11 +131,11 @@ static u8 cpg_div6_clock_get_parent(struct clk_hw *hw) unsigned int i; u8 hw_index; - if (clock->src_width == 0) + if (clock->src_mask == 0) return 0; - hw_index = (readl(clock->reg) >> clock->src_shift) & - (BIT(clock->src_width) - 1); + hw_index = (readl(clock->reg) & clock->src_mask) >> + __ffs(clock->src_mask); for (i = 0; i < clk_hw_get_num_parents(hw); i++) { if (clock->parents[i] == hw_index) return i; @@ -151,18 +149,13 @@ static u8 cpg_div6_clock_get_parent(struct clk_hw *hw) static int cpg_div6_clock_set_parent(struct clk_hw *hw, u8 index) { struct div6_clock *clock = to_div6_clock(hw); - u8 hw_index; - u32 mask; + u32 src; if (index >= clk_hw_get_num_parents(hw)) return -EINVAL; - mask = ~((BIT(clock->src_width) - 1) << clock->src_shift); - hw_index = clock->parents[index]; - - writel((readl(clock->reg) & mask) | (hw_index << clock->src_shift), - clock->reg); - + src = clock->parents[index] << __ffs(clock->src_mask); + writel((readl(clock->reg) & ~clock->src_mask) | src, clock->reg); return 0; } @@ -236,17 +229,15 @@ struct clk * __init cpg_div6_register(const char *name, switch (num_parents) { case 1: /* fixed parent clock */ - clock->src_shift = clock->src_width = 0; + clock->src_mask = 0; break; case 4: /* clock with EXSRC bits 6-7 */ - clock->src_shift = 6; - clock->src_width = 2; + clock->src_mask = GENMASK(7, 6); break; case 8: /* VCLK with EXSRC bits 12-14 */ - clock->src_shift = 12; - clock->src_width = 3; + clock->src_mask = GENMASK(14, 12); break; default: pr_err("%s: invalid number of parents for DIV6 clock %s\n", -- 2.7.4