[U-Boot] [RFC PATCH 5/8] arm, davinci: Replace pinmuxing in da850_lowlevel.c

[Christian Riesch]

Hello Heiko,

On Wed, Nov 16, 2011 at 7:49 AM, Heiko Schocher <hs at denx.de> wrote:
> Hello Christian,
>
> Christian Riesch wrote:
>> This patch replaces the pinmuxing functions from
>> arch/arm/cpu/arm926ejs/davinci/da850_lowlevel.c by those of
>> arch/arm/cpu/arm926ejs/davinci/pinmux.c
>>
>> Signed-off-by: Christian Riesch <christian.riesch at omicron.at>
>> Cc: Heiko Schocher <hs at denx.de>
>> Cc: Sandeep Paulraj <s-paulraj at ti.com>
>> ---
>>  arch/arm/cpu/arm926ejs/davinci/da850_lowlevel.c |   34 +++++++++--------------
>>  1 files changed, 13 insertions(+), 21 deletions(-)
>>
>> diff --git a/arch/arm/cpu/arm926ejs/davinci/da850_lowlevel.c b/arch/arm/cpu/arm926ejs/davinci/da850_lowlevel.c
>> index c7ec70f..8dd897b 100644
>> --- a/arch/arm/cpu/arm926ejs/davinci/da850_lowlevel.c
>> +++ b/arch/arm/cpu/arm926ejs/davinci/da850_lowlevel.c
>> @@ -30,6 +30,7 @@
>>  #include <asm/arch/ddr2_defs.h>
>>  #include <asm/arch/emif_defs.h>
>>  #include <asm/arch/pll_defs.h>
>> +#include <asm/arch/davinci_misc.h>
>>
>>  void da850_waitloop(unsigned long loopcnt)
>>  {
>> @@ -248,6 +249,16 @@ void board_gpio_init(void)
>>       return;
>>  }
>>
>> +/* UART pin muxer settings */
>> +static const struct pinmux_config uart_pins[] = {
>> +#if CONFIG_SYS_NS16550_COM1 == DAVINCI_UART2_BASE
>> +     { pinmux(0), 4, 6 },
>> +     { pinmux(0), 4, 7 },
>> +     { pinmux(4), 2, 4 },
>> +     { pinmux(4), 2, 5 }
>> +#endif
>> +};
>> +
>>  int arch_cpu_init(void)
>>  {
>>       /* Unlock kick registers */
>> @@ -257,27 +268,8 @@ int arch_cpu_init(void)
>>       dv_maskbits(&davinci_syscfg_regs->suspsrc,
>>               CONFIG_SYS_DA850_SYSCFG_SUSPSRC);
>>
>> -     /* Setup Pinmux */
>> -     da850_pinmux_ctl(0, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX0);
>> -     da850_pinmux_ctl(1, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX1);
>> -     da850_pinmux_ctl(2, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX2);
>> -     da850_pinmux_ctl(3, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX3);
>> -     da850_pinmux_ctl(4, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX4);
>> -     da850_pinmux_ctl(5, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX5);
>> -     da850_pinmux_ctl(6, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX6);
>> -     da850_pinmux_ctl(7, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX7);
>> -     da850_pinmux_ctl(8, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX8);
>> -     da850_pinmux_ctl(9, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX9);
>> -     da850_pinmux_ctl(10, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX10);
>> -     da850_pinmux_ctl(11, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX11);
>> -     da850_pinmux_ctl(12, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX12);
>> -     da850_pinmux_ctl(13, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX13);
>> -     da850_pinmux_ctl(14, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX14);
>> -     da850_pinmux_ctl(15, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX15);
>> -     da850_pinmux_ctl(16, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX16);
>> -     da850_pinmux_ctl(17, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX17);
>> -     da850_pinmux_ctl(18, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX18);
>> -     da850_pinmux_ctl(19, 0xFFFFFFFF, CONFIG_SYS_DA850_PINMUX19);
>> +     /* setup serial port */
>> +     davinci_configure_pin_mux(uart_pins, ARRAY_SIZE(uart_pins));
>
> Why only the uart pins? We could use here something like "board_pins"
> and initialize here all pins for the board?

Because only the UART pins are required here. Since the CPU has
already loaded the SPL from SPI flash or is executing the SPL from NOR
flash or whatever, the pins for memory access are already configured.
Later the board specific file can do all the configuration that it
actually needs, see board/davinci/da8xxevm/da850evm.c.

> I reworked this for the enbw_cmc board too, and removed also the
> CONFIG_SYS_DA850_PINMUX* defines complete ... but I am not really
> happy with it. Why?
>
> We have for example on the am1808 19 * 8 = 152 pins to setup up
>
> If using the CONFIG_SYS_DA850_PINMUX* defines we have 19 register-
> writes and have setup them all (And you must think about all
> your pins, if we use such a struct, not defined pins are in
> default state ... which is good or bad ...)
>
> With using davinci_configure_pin_mux() we have 152 * (read, write
> and some logic operations)

Actually the number of read, writes, logic operations will depend on
the number of GPIO pins you use on your board. I guess you will not
change the pinmux settings of pins you didn't connect on your board.
But yes, these are a lot of operations that need to be done.

... and I have to code a "static const
> struct pinmux_config board_pins" with 152 lines in the code ...

How about using an approach like in board/davinci/da8xxevm/da850evm.c.
There we have several structs like

static const struct pinmux config_spi1_pins[] = {
...
}

that defines pinmux for groups of pins that are usually used together.

Later, these groups are put together in

static const struct pinmux_resource pinmuxes[] = {

}


>
> What do others think?
>
> bye,
> Heiko
> --
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> _______________________________________________
> U-Boot mailing list
> U-Boot at lists.denx.de
> http://lists.denx.de/mailman/listinfo/u-boot
>