AM335X uart

shanqing liu

Intellectual 635 points

Hi ,

I want to use am335x uart0 uart2 uart4 uart5. uart0 is debug console.

Now uart0 uart2 uart5 is ok, but uart4 is not work.

I change kernel as follow:

In function board-am335xevm.c ,I add:

static void uart4_init(int evm_id, int profile)
{
setup_pin_mux(uart4_pin_mux);
return;
}

static struct pinmux_config uart4_pin_mux[] = {
   {"uart0_rtsn.uart4_txd", OMAP_MUX_MODE1 | AM33XX_PULL_ENBL | AM33XX_INPUT_DISA},
   {"uart0_ctsn.uart4_rxd", OMAP_MUX_MODE1 | AM33XX_PIN_INPUT_PULLUP},
   {NULL, 0},
};

and change mux33xx.c:

    _AM33XX_MUXENTRY(UART0_CTSN, 0,
       "uart0_ctsn", "uart4_rxd", "d_can1_tx", "i2c1_sda",
       "spi1_d0", NULL, NULL, "gpio1_8"),
   _AM33XX_MUXENTRY(UART0_RTSN, 0,
       "uart0_rtsn", "uart4_txd", "d_can1_rx", "i2c1_scl",
       "spi1_d1", "spi1_cs0", NULL, "gpio1_9"),

I also read the CM_PER_UART4_CLKCTRL Register, the value is 2.

and register 0x44e10968 0x44e1096C (conf_uart0_ctsn register and conf_uart0_rtsn) ,the value is 0x31 and 0x01.

So what's wrong with me? what else should I do?

Thank you.

over 11 years ago

0 shanqing liu over 11 years ago

Intellectual 635 points

the kernel also regist uart4:

[    0.237396] omap_uart.0: ttyO0 at MMIO 0x44e09000 (irq = 72) is a OMAP UART0
[    0.882324] console [ttyO0] enabled
[    0.886535] omap_uart.1: ttyO1 at MMIO 0x48022000 (irq = 73) is a OMAP UART1
[    0.894348] omap_uart.2: ttyO2 at MMIO 0x48024000 (irq = 74) is a OMAP UART2
[    0.902130] omap_uart.3: ttyO3 at MMIO 0x481a6000 (irq = 44) is a OMAP UART3
[    0.909912] omap_uart.4: ttyO4 at MMIO 0x481a8000 (irq = 45) is a OMAP UART4
[    0.917694] omap_uart.5: ttyO5 at MMIO 0x481aa000 (irq = 46) is a OMAP UART5

0 Sichao Tang over 11 years ago in reply to shanqing liu

Intellectual 395 points

HI,

where your pin_mux function is invoked? In fact , whether the pins are muxed or not , the uarts from 0 to 5 are always register by the kernel , this is archived by seriel.c .Thank you.

0 shanqing liu over 11 years ago in reply to Sichao Tang

Intellectual 635 points

Thank you for your repley.

These pins is muxed or not , can read the register to verify. I mentioned in my first post ,the register value can certify the pin mux is right.

Thanks.

0 shanqing liu over 11 years ago in reply to shanqing liu

Intellectual 635 points

My problem has been resolved.

Thanks.

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AM335X uart