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* [PATCH] OMAP2/3 clock: convert mask_to_shift() to __ffs()
@ 2008-03-28  6:26 Paul Walmsley
  2008-03-28 10:15 ` Tony Lindgren
  0 siblings, 1 reply; 2+ messages in thread
From: Paul Walmsley @ 2008-03-28  6:26 UTC (permalink / raw)
  To: linux-omap


In OMAP2/3 clock code, we've used mask_to_shift() to convert bitmasks
into shift values, via "ffs(mask) - 1".  It turns out that there is
already a Linux idiom for this in asm/bitops.h: __ffs().  (Not to be
confused with ffs(), of course.  You wouldn't do that, would you?)
When in Rome, do as the Romans.

Signed-off-by: Paul Walmsley <paul@pwsan.com>

---
 arch/arm/mach-omap2/clock.c     |   18 +++++++-----------
 arch/arm/mach-omap2/clock.h     |    1 -
 arch/arm/mach-omap2/clock24xx.c |    5 +++--
 arch/arm/mach-omap2/clock34xx.c |    4 ++--
 4 files changed, 12 insertions(+), 16 deletions(-)

Index: linux-omap/arch/arm/mach-omap2/clock.c
===================================================================
--- linux-omap.orig/arch/arm/mach-omap2/clock.c	2008-03-27 19:06:55.000000000 -0600
+++ linux-omap/arch/arm/mach-omap2/clock.c	2008-03-27 19:11:41.000000000 -0600
@@ -21,6 +21,7 @@
 #include <linux/errno.h>
 #include <linux/delay.h>
 #include <linux/clk.h>
+#include <asm/bitops.h>
 
 #include <asm/io.h>
 
@@ -46,11 +47,6 @@
  * Omap2 specific clock functions
  *-------------------------------------------------------------------------*/
 
-u8 mask_to_shift(u32 mask)
-{
-	return ffs(mask) - 1;
-}
-
 /**
  * omap2_init_clksel_parent - set a clksel clk's parent field from the hardware
  * @clk: OMAP clock struct ptr to use
@@ -69,7 +65,7 @@
 		return;
 
 	r = __raw_readl(clk->clksel_reg) & clk->clksel_mask;
-	r >>= mask_to_shift(clk->clksel_mask);
+	r >>= __ffs(clk->clksel_mask);
 
 	for (clks = clk->clksel; clks->parent && !found; clks++) {
 		for (clkr = clks->rates; clkr->div && !found; clkr++) {
@@ -108,9 +104,9 @@
 
 	dpll = cm_read_reg(dd->mult_div1_reg);
 	dpll_mult = dpll & dd->mult_mask;
-	dpll_mult >>= mask_to_shift(dd->mult_mask);
+	dpll_mult >>= __ffs(dd->mult_mask);
 	dpll_div = dpll & dd->div1_mask;
-	dpll_div >>= mask_to_shift(dd->div1_mask);
+	dpll_div >>= __ffs(dd->div1_mask);
 
 	dpll_clk = (long long)clk->parent->rate * dpll_mult;
 	do_div(dpll_clk, dpll_div + 1);
@@ -574,7 +570,7 @@
 		return 0;
 
 	field_val = cm_read_reg(div_addr) & field_mask;
-	field_val >>= mask_to_shift(field_mask);
+	field_val >>= __ffs(field_mask);
 
 	return omap2_clksel_to_divisor(clk, field_val);
 }
@@ -598,7 +594,7 @@
 
 	reg_val = cm_read_reg(div_addr);
 	reg_val &= ~field_mask;
-	reg_val |= (field_val << mask_to_shift(field_mask));
+	reg_val |= (field_val << __ffs(field_mask));
 	cm_write_reg(reg_val, div_addr);
 	wmb();
 
@@ -696,7 +692,7 @@
 
 	/* Set new source value (previous dividers if any in effect) */
 	reg_val = __raw_readl(src_addr) & ~field_mask;
-	reg_val |= (field_val << mask_to_shift(field_mask));
+	reg_val |= (field_val << __ffs(field_mask));
 	__raw_writel(reg_val, src_addr);
 	wmb();
 
Index: linux-omap/arch/arm/mach-omap2/clock.h
===================================================================
--- linux-omap.orig/arch/arm/mach-omap2/clock.h	2008-03-27 19:06:55.000000000 -0600
+++ linux-omap/arch/arm/mach-omap2/clock.h	2008-03-27 19:10:08.000000000 -0600
@@ -42,7 +42,6 @@
 int omap2_clksel_set_rate(struct clk *clk, unsigned long rate);
 u32 omap2_get_dpll_rate(struct clk *clk);
 int omap2_wait_clock_ready(void __iomem *reg, u32 cval, const char *name);
-u8 mask_to_shift(u32 mask);
 
 extern u8 cpu_mask;
 
Index: linux-omap/arch/arm/mach-omap2/clock24xx.c
===================================================================
--- linux-omap.orig/arch/arm/mach-omap2/clock24xx.c	2008-03-27 19:01:32.000000000 -0600
+++ linux-omap/arch/arm/mach-omap2/clock24xx.c	2008-03-27 19:13:29.000000000 -0600
@@ -31,6 +31,7 @@
 #include <asm/arch/clock.h>
 #include <asm/arch/sram.h>
 #include <asm/div64.h>
+#include <asm/bitops.h>
 
 #include "memory.h"
 #include "clock.h"
@@ -224,8 +225,8 @@
 			mult = (rate / 1000000);
 			done_rate = CORE_CLK_SRC_DPLL;
 		}
-		tmpset.cm_clksel1_pll |= (div << mask_to_shift(dd->mult_mask));
-		tmpset.cm_clksel1_pll |= (mult << mask_to_shift(dd->div1_mask));
+		tmpset.cm_clksel1_pll |= (div << __ffs(dd->mult_mask));
+		tmpset.cm_clksel1_pll |= (mult << __ffs(dd->div1_mask));
 
 		/* Worst case */
 		tmpset.base_sdrc_rfr = SDRC_RFR_CTRL_BYPASS;
Index: linux-omap/arch/arm/mach-omap2/clock34xx.c
===================================================================
--- linux-omap.orig/arch/arm/mach-omap2/clock34xx.c	2008-03-27 18:01:36.000000000 -0600
+++ linux-omap/arch/arm/mach-omap2/clock34xx.c	2008-03-27 19:13:07.000000000 -0600
@@ -22,12 +22,12 @@
 #include <linux/errno.h>
 #include <linux/delay.h>
 #include <linux/clk.h>
-
 #include <linux/io.h>
 
 #include <asm/arch/clock.h>
 #include <asm/arch/sram.h>
 #include <asm/div64.h>
+#include <asm/bitops.h>
 
 #include "memory.h"
 #include "clock.h"
@@ -79,7 +79,7 @@
 	WARN_ON(!dd->control_reg || !dd->enable_mask);
 
 	v = cm_read_reg(dd->control_reg) & dd->enable_mask;
-	v >>= mask_to_shift(dd->enable_mask);
+	v >>= __ffs(dd->enable_mask);
 	if (v != DPLL_LOCKED)
 		clk->rate = clk->parent->rate;
 	else

^ permalink raw reply	[flat|nested] 2+ messages in thread

* Re: [PATCH] OMAP2/3 clock: convert mask_to_shift() to __ffs()
  2008-03-28  6:26 [PATCH] OMAP2/3 clock: convert mask_to_shift() to __ffs() Paul Walmsley
@ 2008-03-28 10:15 ` Tony Lindgren
  0 siblings, 0 replies; 2+ messages in thread
From: Tony Lindgren @ 2008-03-28 10:15 UTC (permalink / raw)
  To: Paul Walmsley; +Cc: linux-omap

* Paul Walmsley <paul@pwsan.com> [080328 08:26]:
> 
> In OMAP2/3 clock code, we've used mask_to_shift() to convert bitmasks
> into shift values, via "ffs(mask) - 1".  It turns out that there is
> already a Linux idiom for this in asm/bitops.h: __ffs().  (Not to be
> confused with ffs(), of course.  You wouldn't do that, would you?)
> When in Rome, do as the Romans.

Pushing today & folding this into the omap2-upstream series.

Tony


> 
> Signed-off-by: Paul Walmsley <paul@pwsan.com>
> 
> ---
>  arch/arm/mach-omap2/clock.c     |   18 +++++++-----------
>  arch/arm/mach-omap2/clock.h     |    1 -
>  arch/arm/mach-omap2/clock24xx.c |    5 +++--
>  arch/arm/mach-omap2/clock34xx.c |    4 ++--
>  4 files changed, 12 insertions(+), 16 deletions(-)
> 
> Index: linux-omap/arch/arm/mach-omap2/clock.c
> ===================================================================
> --- linux-omap.orig/arch/arm/mach-omap2/clock.c	2008-03-27 19:06:55.000000000 -0600
> +++ linux-omap/arch/arm/mach-omap2/clock.c	2008-03-27 19:11:41.000000000 -0600
> @@ -21,6 +21,7 @@
>  #include <linux/errno.h>
>  #include <linux/delay.h>
>  #include <linux/clk.h>
> +#include <asm/bitops.h>
>  
>  #include <asm/io.h>
>  
> @@ -46,11 +47,6 @@
>   * Omap2 specific clock functions
>   *-------------------------------------------------------------------------*/
>  
> -u8 mask_to_shift(u32 mask)
> -{
> -	return ffs(mask) - 1;
> -}
> -
>  /**
>   * omap2_init_clksel_parent - set a clksel clk's parent field from the hardware
>   * @clk: OMAP clock struct ptr to use
> @@ -69,7 +65,7 @@
>  		return;
>  
>  	r = __raw_readl(clk->clksel_reg) & clk->clksel_mask;
> -	r >>= mask_to_shift(clk->clksel_mask);
> +	r >>= __ffs(clk->clksel_mask);
>  
>  	for (clks = clk->clksel; clks->parent && !found; clks++) {
>  		for (clkr = clks->rates; clkr->div && !found; clkr++) {
> @@ -108,9 +104,9 @@
>  
>  	dpll = cm_read_reg(dd->mult_div1_reg);
>  	dpll_mult = dpll & dd->mult_mask;
> -	dpll_mult >>= mask_to_shift(dd->mult_mask);
> +	dpll_mult >>= __ffs(dd->mult_mask);
>  	dpll_div = dpll & dd->div1_mask;
> -	dpll_div >>= mask_to_shift(dd->div1_mask);
> +	dpll_div >>= __ffs(dd->div1_mask);
>  
>  	dpll_clk = (long long)clk->parent->rate * dpll_mult;
>  	do_div(dpll_clk, dpll_div + 1);
> @@ -574,7 +570,7 @@
>  		return 0;
>  
>  	field_val = cm_read_reg(div_addr) & field_mask;
> -	field_val >>= mask_to_shift(field_mask);
> +	field_val >>= __ffs(field_mask);
>  
>  	return omap2_clksel_to_divisor(clk, field_val);
>  }
> @@ -598,7 +594,7 @@
>  
>  	reg_val = cm_read_reg(div_addr);
>  	reg_val &= ~field_mask;
> -	reg_val |= (field_val << mask_to_shift(field_mask));
> +	reg_val |= (field_val << __ffs(field_mask));
>  	cm_write_reg(reg_val, div_addr);
>  	wmb();
>  
> @@ -696,7 +692,7 @@
>  
>  	/* Set new source value (previous dividers if any in effect) */
>  	reg_val = __raw_readl(src_addr) & ~field_mask;
> -	reg_val |= (field_val << mask_to_shift(field_mask));
> +	reg_val |= (field_val << __ffs(field_mask));
>  	__raw_writel(reg_val, src_addr);
>  	wmb();
>  
> Index: linux-omap/arch/arm/mach-omap2/clock.h
> ===================================================================
> --- linux-omap.orig/arch/arm/mach-omap2/clock.h	2008-03-27 19:06:55.000000000 -0600
> +++ linux-omap/arch/arm/mach-omap2/clock.h	2008-03-27 19:10:08.000000000 -0600
> @@ -42,7 +42,6 @@
>  int omap2_clksel_set_rate(struct clk *clk, unsigned long rate);
>  u32 omap2_get_dpll_rate(struct clk *clk);
>  int omap2_wait_clock_ready(void __iomem *reg, u32 cval, const char *name);
> -u8 mask_to_shift(u32 mask);
>  
>  extern u8 cpu_mask;
>  
> Index: linux-omap/arch/arm/mach-omap2/clock24xx.c
> ===================================================================
> --- linux-omap.orig/arch/arm/mach-omap2/clock24xx.c	2008-03-27 19:01:32.000000000 -0600
> +++ linux-omap/arch/arm/mach-omap2/clock24xx.c	2008-03-27 19:13:29.000000000 -0600
> @@ -31,6 +31,7 @@
>  #include <asm/arch/clock.h>
>  #include <asm/arch/sram.h>
>  #include <asm/div64.h>
> +#include <asm/bitops.h>
>  
>  #include "memory.h"
>  #include "clock.h"
> @@ -224,8 +225,8 @@
>  			mult = (rate / 1000000);
>  			done_rate = CORE_CLK_SRC_DPLL;
>  		}
> -		tmpset.cm_clksel1_pll |= (div << mask_to_shift(dd->mult_mask));
> -		tmpset.cm_clksel1_pll |= (mult << mask_to_shift(dd->div1_mask));
> +		tmpset.cm_clksel1_pll |= (div << __ffs(dd->mult_mask));
> +		tmpset.cm_clksel1_pll |= (mult << __ffs(dd->div1_mask));
>  
>  		/* Worst case */
>  		tmpset.base_sdrc_rfr = SDRC_RFR_CTRL_BYPASS;
> Index: linux-omap/arch/arm/mach-omap2/clock34xx.c
> ===================================================================
> --- linux-omap.orig/arch/arm/mach-omap2/clock34xx.c	2008-03-27 18:01:36.000000000 -0600
> +++ linux-omap/arch/arm/mach-omap2/clock34xx.c	2008-03-27 19:13:07.000000000 -0600
> @@ -22,12 +22,12 @@
>  #include <linux/errno.h>
>  #include <linux/delay.h>
>  #include <linux/clk.h>
> -
>  #include <linux/io.h>
>  
>  #include <asm/arch/clock.h>
>  #include <asm/arch/sram.h>
>  #include <asm/div64.h>
> +#include <asm/bitops.h>
>  
>  #include "memory.h"
>  #include "clock.h"
> @@ -79,7 +79,7 @@
>  	WARN_ON(!dd->control_reg || !dd->enable_mask);
>  
>  	v = cm_read_reg(dd->control_reg) & dd->enable_mask;
> -	v >>= mask_to_shift(dd->enable_mask);
> +	v >>= __ffs(dd->enable_mask);
>  	if (v != DPLL_LOCKED)
>  		clk->rate = clk->parent->rate;
>  	else
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo@vger.kernel.org
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^ permalink raw reply	[flat|nested] 2+ messages in thread

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2008-03-28  6:26 [PATCH] OMAP2/3 clock: convert mask_to_shift() to __ffs() Paul Walmsley
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