diff options
author | Shawn Guo <shawn.guo@freescale.com> | 2014-04-19 10:58:22 +0800 |
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committer | Shawn Guo <shawn.guo@freescale.com> | 2014-05-12 22:58:48 +0800 |
commit | f9f28cdf21679792c30d9f5eebd01b7e04fe658f (patch) | |
tree | 6a1d608fd6eaeee70eeab2d00100394e0c95fb32 /arch/arm/mach-imx/clk-gate2.c | |
parent | 94b5c0288299c7b962a7e2cb734293b77b96cffe (diff) | |
download | op-kernel-dev-f9f28cdf21679792c30d9f5eebd01b7e04fe658f.zip op-kernel-dev-f9f28cdf21679792c30d9f5eebd01b7e04fe658f.tar.gz |
ARM: imx: add shared gate clock support
It's quite common on i.MX that one gate bit controls the gating of
multiple clocks, i.e. this is a shared gate. The patch adds the
function imx_clk_gate2_shared() for such case. The clocks controlled
by the same gate bits should call this function with a pointer to a
single share count variable, so that the gate bits will only be
operated on the first enabling and the last disabling of these shared
gate clocks.
Thanks to Gerhard Sittig <gsi@denx.de> for this idea.
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>
Diffstat (limited to 'arch/arm/mach-imx/clk-gate2.c')
-rw-r--r-- | arch/arm/mach-imx/clk-gate2.c | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/arch/arm/mach-imx/clk-gate2.c b/arch/arm/mach-imx/clk-gate2.c index 0803df9..4ba587d 100644 --- a/arch/arm/mach-imx/clk-gate2.c +++ b/arch/arm/mach-imx/clk-gate2.c @@ -33,6 +33,7 @@ struct clk_gate2 { u8 bit_idx; u8 flags; spinlock_t *lock; + unsigned int *share_count; }; #define to_clk_gate2(_hw) container_of(_hw, struct clk_gate2, hw) @@ -45,10 +46,14 @@ static int clk_gate2_enable(struct clk_hw *hw) spin_lock_irqsave(gate->lock, flags); + if (gate->share_count && (*gate->share_count)++ > 0) + goto out; + reg = readl(gate->reg); reg |= 3 << gate->bit_idx; writel(reg, gate->reg); +out: spin_unlock_irqrestore(gate->lock, flags); return 0; @@ -62,10 +67,14 @@ static void clk_gate2_disable(struct clk_hw *hw) spin_lock_irqsave(gate->lock, flags); + if (gate->share_count && --(*gate->share_count) > 0) + goto out; + reg = readl(gate->reg); reg &= ~(3 << gate->bit_idx); writel(reg, gate->reg); +out: spin_unlock_irqrestore(gate->lock, flags); } @@ -91,7 +100,8 @@ static struct clk_ops clk_gate2_ops = { struct clk *clk_register_gate2(struct device *dev, const char *name, const char *parent_name, unsigned long flags, void __iomem *reg, u8 bit_idx, - u8 clk_gate2_flags, spinlock_t *lock) + u8 clk_gate2_flags, spinlock_t *lock, + unsigned int *share_count) { struct clk_gate2 *gate; struct clk *clk; @@ -106,6 +116,7 @@ struct clk *clk_register_gate2(struct device *dev, const char *name, gate->bit_idx = bit_idx; gate->flags = clk_gate2_flags; gate->lock = lock; + gate->share_count = share_count; init.name = name; init.ops = &clk_gate2_ops; |