[U-Boot] [PATCH v4] ns16550: change to allow 32 bit access to registers

[U-Boot] [PATCH v4] ns16550: change to allow 32 bit access to registers

[Dave Aldridge]

If CONFIG_SYS_NS16550_MEM32 is defined then 32 bit memory
mapped access will be used to read/write the uart registers.

This is especially useful for SoC devices that implement 16550
compatible uarts but that have peripheral access width constraints.

Signed-off-by: Dave Aldridge <fovsoft@gmail.com>
---
Changes for v2:
    - Add endian support

Changes for v3:
    - Use in_be32()/out_be32() and in_le32/out_le32() functions
      to provide endian support

Changes for v4:
    - use u32 instead of unsigned int in include/ns16550.h
      to remove any ambiguity about the register size

 drivers/serial/ns16550.c |    6 ++++++
 include/ns16550.h        |    4 ++++
 2 files changed, 10 insertions(+), 0 deletions(-)

diff --git a/drivers/serial/ns16550.c b/drivers/serial/ns16550.c
index 8eeb48f..0174744 100644
--- a/drivers/serial/ns16550.c
+++ b/drivers/serial/ns16550.c
@@ -19,6 +19,12 @@
 #ifdef CONFIG_SYS_NS16550_PORT_MAPPED
 #define serial_out(x,y)	outb(x,(ulong)y)
 #define serial_in(y)	inb((ulong)y)
+#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
+#define serial_out(x,y) out_be32(y,x)
+#define serial_in(y) 	in_be32(y)
+#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)
+#define serial_out(x,y) out_le32(y,x)
+#define serial_in(y) 	in_le32(y)
 #else
 #define serial_out(x,y) writeb(x,y)
 #define serial_in(y) 	readb(y)
diff --git a/include/ns16550.h b/include/ns16550.h
index 9ea81e9..51f1c17 100644
--- a/include/ns16550.h
+++ b/include/ns16550.h
@@ -21,8 +21,12 @@
  * will not allocate storage for arrays of size 0
  */

+#include <linux/types.h>
+
 #if !defined(CONFIG_SYS_NS16550_REG_SIZE) || (CONFIG_SYS_NS16550_REG_SIZE == 0)
 #error "Please define NS16550 registers size."
+#elif defined(CONFIG_SYS_NS16550_MEM32)
+#define UART_REG(x) u32 x
 #elif (CONFIG_SYS_NS16550_REG_SIZE > 0)
 #define UART_REG(x)						   \
 	unsigned char prepad_##x[CONFIG_SYS_NS16550_REG_SIZE - 1]; \
--
1.7.3.4

[U-Boot] [PATCH v4] ns16550: change to allow 32 bit access to registers

[Wolfgang Denk]

Dear Dave Aldridge,

In message <1314953234-3977-1-git-send-email-fovsoft@gmail.com> you wrote:
> If CONFIG_SYS_NS16550_MEM32 is defined then 32 bit memory
> mapped access will be used to read/write the uart registers.
...
> +#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
> +#define serial_out(x,y) out_be32(y,x)
> +#define serial_in(y) 	in_be32(y)
> +#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)

Please see comment to previous version.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@denx.de
For every complex problem, there is a solution that is simple,  neat,
and wrong.                                               - Mark Twain

[U-Boot] [PATCH v4] ns16550: change to allow 32 bit access to registers

[Dave Aldridge]

Hi Wolfgang

On 07/09/11 22:36, Wolfgang Denk wrote:
> Dear Dave Aldridge,
> 
> In message <1314953234-3977-1-git-send-email-fovsoft@gmail.com> you wrote:
>> If CONFIG_SYS_NS16550_MEM32 is defined then 32 bit memory
>> mapped access will be used to read/write the uart registers.
> ...
>> +#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
>> +#define serial_out(x,y) out_be32(y,x)
>> +#define serial_in(y) 	in_be32(y)
>> +#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)
> 
> Please see comment to previous version.

I think the discussions in the '[U-Boot] [PATCH v3] ns16550:' confirm the above
usage of the _REG_SIZE macro for determining the endianess of the uart is correct.

I can also confirm that the patch does work for me.

Cheers

Dave

[U-Boot] [PATCH v4] ns16550: change to allow 32 bit access to registers

[Wolfgang Denk]

Dear Dave Aldridge,

In message <1314953234-3977-1-git-send-email-fovsoft@gmail.com> you wrote:
> If CONFIG_SYS_NS16550_MEM32 is defined then 32 bit memory
> mapped access will be used to read/write the uart registers.
> 
> This is especially useful for SoC devices that implement 16550
> compatible uarts but that have peripheral access width constraints.
> 
> Signed-off-by: Dave Aldridge <fovsoft@gmail.com>
> ---
> Changes for v2:
>     - Add endian support
> 
> Changes for v3:
>     - Use in_be32()/out_be32() and in_le32/out_le32() functions
>       to provide endian support
> 
> Changes for v4:
>     - use u32 instead of unsigned int in include/ns16550.h
>       to remove any ambiguity about the register size
> 
>  drivers/serial/ns16550.c |    6 ++++++
>  include/ns16550.h        |    4 ++++
>  2 files changed, 10 insertions(+), 0 deletions(-)

Applied, thanks.

Best regards,

Wolfgang Denk

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
Of course there's no reason for it, it's just our policy.