Hello Heiko, I hope this is the complete mail now :-/
On Wed, Nov 16, 2011 at 7:49 AM, Heiko Schocher hs@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@omicron.at Cc: Heiko Schocher hs@denx.de Cc: Sandeep Paulraj s-paulraj@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[] = { { DAVINCI_LPSC_AEMIF }, /* NAND, NOR */ { DAVINCI_LPSC_SPI1 }, /* Serial Flash */ { DAVINCI_LPSC_EMAC }, /* image download */ { DAVINCI_LPSC_UART2 }, /* console */ { DAVINCI_LPSC_GPIO }, };
We could move the pinmux_config structs to a header file which would reduce the code in your board config file to a few lines, you only would need a pinmux_resource struct.
Still we need to do pinmuxing for UART (and maybe also for other pins) in the SPL. How do you like the approach in static void set_mux_conf_regs(void) in arch/arm/cpu/armv7/omap-common/hwinit-common.c? Depending on the context either the pins that are essential for the SPL or all other pins are configured.
This would at least reduce the number of code lines that you need for a new board. And this code would be much easier to understand than this list of magic numbers.
What do others think?
bye, Heiko
Regards, Christian