From d57dfe7508af2b528e26d84792edec1e7d919682 Mon Sep 17 00:00:00 2001 From: Haojian Zhuang Date: Sat, 8 Jun 2013 22:47:18 +0800 Subject: [PATCH] clk: divider: add CLK_DIVIDER_HIWORD_MASK flag In both Hisilicon & Rockchip Cortex-A9 based chips, they don't use the paradigm of reading-changing-writing the register contents. Instead they use a hiword mask to indicate the changed bits. When b01 should be set as setting divider, it also needs to indicate the change by setting hiword mask (b11 << 16). The patch adds divider flag for this usage. Signed-off-by: Heiko Stuebner Signed-off-by: Haojian Zhuang Signed-off-by: Mike Turquette --- drivers/clk/clk-divider.c | 15 +++++++++++++-- include/linux/clk-provider.h | 5 +++++ 2 files changed, 18 insertions(+), 2 deletions(-) diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c index 6024e60e49aa..6d55eb2cb959 100644 --- a/drivers/clk/clk-divider.c +++ b/drivers/clk/clk-divider.c @@ -227,8 +227,12 @@ static int clk_divider_set_rate(struct clk_hw *hw, unsigned long rate, if (divider->lock) spin_lock_irqsave(divider->lock, flags); - val = readl(divider->reg); - val &= ~(div_mask(divider) << divider->shift); + if (divider->flags & CLK_DIVIDER_HIWORD_MASK) { + val = div_mask(divider) << (divider->shift + 16); + } else { + val = readl(divider->reg); + val &= ~(div_mask(divider) << divider->shift); + } val |= value << divider->shift; writel(val, divider->reg); @@ -255,6 +259,13 @@ static struct clk *_register_divider(struct device *dev, const char *name, struct clk *clk; struct clk_init_data init; + if (clk_divider_flags & CLK_DIVIDER_HIWORD_MASK) { + if (width + shift > 16) { + pr_warn("divider value exceeds LOWORD field\n"); + return ERR_PTR(-EINVAL); + } + } + /* allocate the divider */ div = kzalloc(sizeof(struct clk_divider), GFP_KERNEL); if (!div) { diff --git a/include/linux/clk-provider.h b/include/linux/clk-provider.h index 37ad97961e5a..d77f1267f419 100644 --- a/include/linux/clk-provider.h +++ b/include/linux/clk-provider.h @@ -257,6 +257,10 @@ struct clk_div_table { * Some hardware implementations gracefully handle this case and allow a * zero divisor by not modifying their input clock * (divide by one / bypass). + * CLK_DIVIDER_HIWORD_MASK - The divider settings are only in lower 16-bit + * of this register, and mask of divider bits are in higher 16-bit of this + * register. While setting the divider bits, higher 16-bit should also be + * updated to indicate changing divider bits. */ struct clk_divider { struct clk_hw hw; @@ -271,6 +275,7 @@ struct clk_divider { #define CLK_DIVIDER_ONE_BASED BIT(0) #define CLK_DIVIDER_POWER_OF_TWO BIT(1) #define CLK_DIVIDER_ALLOW_ZERO BIT(2) +#define CLK_DIVIDER_HIWORD_MASK BIT(3) extern const struct clk_ops clk_divider_ops; struct clk *clk_register_divider(struct device *dev, const char *name, -- 2.34.1