[U-Boot] [PATCH] blackfin: gpio: Use proper mask for comparing function

[U-Boot] [PATCH] blackfin: gpio: Use proper mask for comparing function

[Axel Lin]

The function return from P_FUNCT2MUX(per) takes 2 bits, however
for BF537_FAMILY with offset != 1 the function is 1 bit.

Also has small refactor for better readability.
In portmux_setup(), it looks odd having "muxreg &= ~(3 << 1);"
while in current code we do muxreg |= (function << offset);.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
---
 arch/blackfin/cpu/gpio.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/arch/blackfin/cpu/gpio.c b/arch/blackfin/cpu/gpio.c
index f74a0b7..c4cddaf 100644
--- a/arch/blackfin/cpu/gpio.c
+++ b/arch/blackfin/cpu/gpio.c
@@ -247,7 +247,7 @@ static struct {
 
 static void portmux_setup(unsigned short per)
 {
-	u16 y, offset, muxreg;
+	u16 y, offset, muxreg, mask;
 	u16 function = P_FUNCT2MUX(per);
 
 	for (y = 0; y < ARRAY_SIZE(port_mux_lut); y++) {
@@ -258,12 +258,13 @@ static void portmux_setup(unsigned short per)
 			offset = port_mux_lut[y].offset;
 			muxreg = bfin_read_PORT_MUX();
 
-			if (offset != 1)
-				muxreg &= ~(1 << offset);
+			if (offset == 1)
+				mask = 3;
 			else
-				muxreg &= ~(3 << 1);
+				mask = 1;
 
-			muxreg |= (function << offset);
+			muxreg &= ~(mask << offset);
+			muxreg |= ((function & mask) << offset);
 			bfin_write_PORT_MUX(muxreg);
 		}
 	}
-- 
1.8.1.2

[U-Boot] [PATCH] blackfin: gpio: Use proper mask for comparing function

[Sonic Zhang]

Acked-by: Sonic Zhang <sonic.zhang@analog.com>

On Fri, Jun 28, 2013 at 2:45 PM, Axel Lin <axel.lin@ingics.com> wrote:
> The function return from P_FUNCT2MUX(per) takes 2 bits, however
> for BF537_FAMILY with offset != 1 the function is 1 bit.
>
> Also has small refactor for better readability.
> In portmux_setup(), it looks odd having "muxreg &= ~(3 << 1);"
> while in current code we do muxreg |= (function << offset);.
>
> Signed-off-by: Axel Lin <axel.lin@ingics.com>
> ---
>  arch/blackfin/cpu/gpio.c | 11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/arch/blackfin/cpu/gpio.c b/arch/blackfin/cpu/gpio.c
> index f74a0b7..c4cddaf 100644
> --- a/arch/blackfin/cpu/gpio.c
> +++ b/arch/blackfin/cpu/gpio.c
> @@ -247,7 +247,7 @@ static struct {
>
>  static void portmux_setup(unsigned short per)
>  {
> -       u16 y, offset, muxreg;
> +       u16 y, offset, muxreg, mask;
>         u16 function = P_FUNCT2MUX(per);
>
>         for (y = 0; y < ARRAY_SIZE(port_mux_lut); y++) {
> @@ -258,12 +258,13 @@ static void portmux_setup(unsigned short per)
>                         offset = port_mux_lut[y].offset;
>                         muxreg = bfin_read_PORT_MUX();
>
> -                       if (offset != 1)
> -                               muxreg &= ~(1 << offset);
> +                       if (offset == 1)
> +                               mask = 3;
>                         else
> -                               muxreg &= ~(3 << 1);
> +                               mask = 1;
>
> -                       muxreg |= (function << offset);
> +                       muxreg &= ~(mask << offset);
> +                       muxreg |= ((function & mask) << offset);
>                         bfin_write_PORT_MUX(muxreg);
>                 }
>         }
> --
> 1.8.1.2
>
>
>
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