AM437x UART debug console change in U-boot

Hi All,

I am working on AM437x SOC and I am trying to change UART debug console from default port UART0 to UART5 in out custom board.

I would like to confirm my changes in the u-boot source for my custom board to make use of UART5 as debug console. The below are the changes I have done in my u-boot source to use UART5 as debug console.

Kindly please have a look and let me know is these changes are fine, or need to do any extra changes in the u-boot source for UART5 port.

1. Pin MUX configuration for UART5.

Added the below changes in the following file "board/ti/am43xx/mux.c"  to support UART5 Pinx MUX configuration.

static struct module_pin_mux uart5_pin_mux[] = {
{OFFSET(mii1_col), (MODE(3) | PULLUP_EN | RXACTIVE | SLEWCTRL)},
{OFFSET(rmii1_refclk), (MODE(3) | PULLUDDIS | PULLUP_EN | SLEWCTRL)},
{-1},
}; 

Added function call to configure pin mux for UART5. 

void enable_uart5_pin_mux(void)
{
 configure_module_pin_mux(uart5_pin_mux);
}

2. Edited the file "board/ti/am43xx/board.c" to add required changes for UART5 pin mux.

void set_uart_mux_conf(void)
{
 //enable_uart0_pin_mux();
 enable_uart5_pin_mux();     /*added for UART5 */
}

3. Changes in file "board/ti/am43xx/board.h"

Added prototype declaration for function "enable_uart5_pin_mux()" 

void enable_uart5_pin_mux(void);

4. Added uart clock for UART5 in the file "arch/arm/cpu/armv7/am33xx/clock_am43xx.c"

in the function: "setup_clocks_for_console(void), edited the below lines to add support for UART5.

/* Enable UART5 */
 clrsetbits_le32(&cmper->uart5clkctrl,
 MODULE_CLKCTRL_MODULEMODE_MASK,
 MODULE_CLKCTRL_MODULEMODE_SW_EXPLICIT_EN <<
 MODULE_CLKCTRL_MODULEMODE_SHIFT);

 while ((idlest == MODULE_CLKCTRL_IDLEST_DISABLED) ||
 (idlest == MODULE_CLKCTRL_IDLEST_TRANSITIONING)) {
 clkctrl = readl(&cmper->uart5clkctrl);
 idlest = (clkctrl & MODULE_CLKCTRL_IDLEST_MASK) >>
 MODULE_CLKCTRL_IDLEST_SHIFT;
 }

5. Added uart clock reset support for UART5 in the file "arch/arm/cpu/armv7/am33xx/board.c"

/*Added UART base address macro in the same file*/

#define UART5_BASE_ADD 0x481AA000

static void uart_soft_reset(void)
{
struct uart_sys *uart_base = (struct uart_sys *)UART5_BASE_ADD;
u32 regval;

regval = readl(&uart_base->uartsyscfg);
regval |= UART_RESET;
writel(regval, &uart_base->uartsyscfg);
while ((readl(&uart_base->uartsyssts) &
UART_CLK_RUNNING_MASK) != UART_CLK_RUNNING_MASK)
 ;

 /* Disable smart idle */
 regval = readl(&uart_base->uartsyscfg);
 regval |= UART_SMART_IDLE_EN;
 writel(regval, &uart_base->uartsyscfg);
}

6. Edited make file of the following path "board/ti/am43xx/Makefile" to generate mux obj file to link.

ifeq ($(CONFIG_SKIP_LOWLEVEL_INIT),)
obj-y := mux.o
endif
obj-y := mux.o

obj-y += board.o

7. Added UART5 base address and port configuration in the "include/configs/am43xx_evm.h" file as shown below.

#define CONFIG_SYS_NS16550_COM6 0x481aa000 /* Base custom board has UART5 */

Replaced the boot-args parameter ""console=ttyO0,115200n8\0" \" to ""console=ttyO5,115200n8\0" \ " to support UART5 console.

I appreciate your support on this.

Thanks & Regards

Ch. Siva