diff options
author | Shawn Guo <shawn.guo@freescale.com> | 2014-04-19 10:58:22 +0800 |
---|---|---|
committer | Shawn Guo <shawn.guo@freescale.com> | 2014-05-12 22:58:48 +0800 |
commit | f9f28cdf21679792c30d9f5eebd01b7e04fe658f (patch) | |
tree | 6a1d608fd6eaeee70eeab2d00100394e0c95fb32 | |
parent | 94b5c0288299c7b962a7e2cb734293b77b96cffe (diff) |
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>
-rw-r--r-- | arch/arm/mach-imx/clk-gate2.c | 13 | ||||
-rw-r--r-- | arch/arm/mach-imx/clk.h | 13 |
2 files changed, 23 insertions, 3 deletions
diff --git a/arch/arm/mach-imx/clk-gate2.c b/arch/arm/mach-imx/clk-gate2.c index 0803df9d9c7e..4ba587da89d2 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; diff --git a/arch/arm/mach-imx/clk.h b/arch/arm/mach-imx/clk.h index 048c5ad8a80b..e29f6ebe9f39 100644 --- a/arch/arm/mach-imx/clk.h +++ b/arch/arm/mach-imx/clk.h @@ -28,7 +28,8 @@ struct clk *imx_clk_pllv3(enum imx_pllv3_type type, const char *name, 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_gate_flags, spinlock_t *lock); + u8 clk_gate_flags, spinlock_t *lock, + unsigned int *share_count); struct clk * imx_obtain_fixed_clock( const char *name, unsigned long rate); @@ -37,7 +38,15 @@ static inline struct clk *imx_clk_gate2(const char *name, const char *parent, void __iomem *reg, u8 shift) { return clk_register_gate2(NULL, name, parent, CLK_SET_RATE_PARENT, reg, - shift, 0, &imx_ccm_lock); + shift, 0, &imx_ccm_lock, NULL); +} + +static inline struct clk *imx_clk_gate2_shared(const char *name, + const char *parent, void __iomem *reg, u8 shift, + unsigned int *share_count) +{ + return clk_register_gate2(NULL, name, parent, CLK_SET_RATE_PARENT, reg, + shift, 0, &imx_ccm_lock, share_count); } struct clk *imx_clk_pfd(const char *name, const char *parent_name, |