[U-Boot] [PATCH resend] at91: Enable slow master clock on meesc board

In some cases, we need low speed master clock. So depending on the "mdiv" variable, the processor clock is divided by 2 (default) or 4.
Signed-off-by: Daniel Gorsulowski Daniel.Gorsulowski@esd.eu --- board/esd/meesc/meesc.c | 24 ++++++++++++++++++++++++ include/configs/meesc.h | 1 + 2 files changed, 25 insertions(+), 0 deletions(-)
diff --git a/board/esd/meesc/meesc.c b/board/esd/meesc/meesc.c index efba60d..4f6c5b7 100644 --- a/board/esd/meesc/meesc.c +++ b/board/esd/meesc/meesc.c @@ -219,6 +219,30 @@ u32 get_board_rev(void) } #endif
+#ifdef CONFIG_MISC_INIT_R +int misc_init_r(void) +{ + char *str; + char buf[32]; + + /* + * In some cases, we need low speed master clock. So depending on the + * "mdiv" variable, the processor clock is divided by 2 (default) or 4. + */ + if ((str = getenv("mdiv")) && (!strcmp(str, "4"))) { + at91_sys_write(AT91_PMC_MCKR, + (at91_sys_read(AT91_PMC_MCKR) & ~AT91_PMC_MDIV) | + AT91SAM9_PMC_MDIV_4); + at91_clock_init(0); + serial_setbrg(); + printf("Setting master clock to %s MHz\n", + strmhz(buf, get_mck_clk_rate())); + } + + return 0; +} +#endif /* CONFIG_MISC_INIT_R */ + int board_init(void) { /* Peripheral Clock Enable Register */ diff --git a/include/configs/meesc.h b/include/configs/meesc.h index b996854..034e81c 100644 --- a/include/configs/meesc.h +++ b/include/configs/meesc.h @@ -48,6 +48,7 @@
#define CONFIG_SKIP_LOWLEVEL_INIT #define CONFIG_SKIP_RELOCATE_UBOOT +#define CONFIG_MISC_INIT_R /* Call misc_init_r */
#define CONFIG_ARCH_CPU_INIT

Daniel Gorsulowski wrote:
In some cases, we need low speed master clock. So depending on the "mdiv" variable, the processor clock is divided by 2 (default) or 4.
Signed-off-by: Daniel Gorsulowski Daniel.Gorsulowski@esd.eu
board/esd/meesc/meesc.c | 24 ++++++++++++++++++++++++ include/configs/meesc.h | 1 + 2 files changed, 25 insertions(+), 0 deletions(-)
diff --git a/board/esd/meesc/meesc.c b/board/esd/meesc/meesc.c index efba60d..4f6c5b7 100644 --- a/board/esd/meesc/meesc.c +++ b/board/esd/meesc/meesc.c @@ -219,6 +219,30 @@ u32 get_board_rev(void) } #endif
+#ifdef CONFIG_MISC_INIT_R +int misc_init_r(void) +{
- char *str;
- char buf[32];
- /*
* In some cases, we need low speed master clock. So depending on the
* "mdiv" variable, the processor clock is divided by 2 (default) or 4.
*/
This comment does not follow what is done. From the comment there should be an 'else' branch where the mdiv_2 is done.
- if ((str = getenv("mdiv")) && (!strcmp(str, "4"))) {
Move the getenv out of the if-check. The string comparision should be strengthened. str = "44" would be valid. Perhaps warn if the expected 2 or 4 is not set.
There are more that 2 and 4 possible clk divisors. Do you want to make this function more general?
at91_sys_write(AT91_PMC_MCKR,
(at91_sys_read(AT91_PMC_MCKR) & ~AT91_PMC_MDIV) |
AT91SAM9_PMC_MDIV_4);
at91_clock_init(0);
serial_setbrg();
printf("Setting master clock to %s MHz\n",
strmhz(buf, get_mck_clk_rate()));
This printf should be moved outside of the if check so the default case also gets the printout.
Tom
- }
- return 0;
+} +#endif /* CONFIG_MISC_INIT_R */
int board_init(void) { /* Peripheral Clock Enable Register */ diff --git a/include/configs/meesc.h b/include/configs/meesc.h index b996854..034e81c 100644 --- a/include/configs/meesc.h +++ b/include/configs/meesc.h @@ -48,6 +48,7 @@
#define CONFIG_SKIP_LOWLEVEL_INIT #define CONFIG_SKIP_RELOCATE_UBOOT +#define CONFIG_MISC_INIT_R /* Call misc_init_r */
#define CONFIG_ARCH_CPU_INIT
participants (2)
-
Daniel Gorsulowski
-
Tom