Hi Jerry:
Thanks , these info are very helpful.
but i still encounter some problem.
by follow your reply.
these are the uart mapping on L4T
tegra19x-mb1-pinmux-p3668-a01.cfg
pinmux.0x024300a8 = 0x00000400; # uart1_tx_pr2: uarta, tristate-disable, input-disable, io_high_voltage-disable, lpdr-disable
pinmux.0x024300a0 = 0x00000454; # uart1_rx_pr3: uarta, pull-down, tristate-enable, input-enable, io_high_voltage-disable, lpdr-disable
pinmux.0x02430098 = 0x00000055; # uart1_rts_pr4: rsvd1, pull-down, tristate-enable, input-enable, lpdr-disable
pinmux.0x02430090 = 0x00000055; # uart1_cts_pr5: rsvd1, pull-down, tristate-enable, input-enable, lpdr-disable
pinmux.0x0243d070 = 0x00000400; # uart2_tx_px4: uartb, tristate-disable, input-disable, io_high_voltage-disable, lpdr-disable
pinmux.0x0243d078 = 0x00000450; # uart2_rx_px5: uartb, tristate-enable, input-enable, io_high_voltage-disable, lpdr-disable
pinmux.0x0243d080 = 0x00000408; # uart2_rts_px6: uartb, pull-up, tristate-disable, input-disable, lpdr-disable
pinmux.0x0243d088 = 0x00000458; # uart2_cts_px7: uartb, pull-up, tristate-enable, input-enable, lpdr-disable
pinmux.0x0c302010 = 0x00000400; # uart3_tx_pcc5: uartc, tristate-disable, input-disable, io_high_voltage-disable, lpdr-disable
pinmux.0x0c302008 = 0x00000450; # uart3_rx_pcc6: uartc, tristate-enable, input-enable, io_high_voltage-disable, lpdr-disable
pinmux spreadsheets
UART1_TXD 203 UART1_TX GPIO3_PR.02
UART1_RXD 205 UART1_RX GPIO3_PR.03
UART1_RTS* 207 UART1_RTS GPIO3_PR.04
UART1_CTS* 209 UART1_CTS GPIO3_PR.05
UART2_TXD 236 UART3_TX GPIO3_PCC.05
UART2_RXD 238 UART3_RX GPIO3_PCC.06
tegra194-soc-uart.dtsi
serial0 = &uarta;
serial1 = &uartb;
serial2 = &uartc;
I enable all these uart , log:
[ 1.437891] 3100000.serial: ttyTHS0 at MMIO 0x3100000 (irq = 47, base_baud = 0) is a TEGRA_UART
[ 1.439066] 3110000.serial: ttyTHS1 at MMIO 0x3110000 (irq = 48, base_baud = 0) is a TEGRA_UART
[ 1.441064] c280000.serial: ttyTHS2 at MMIO 0xc280000 (irq = 49, base_baud = 0) is a TEGRA_UART
[ 1.441848] 3130000.serial: ttyTHS3 at MMIO 0x3130000 (irq = 50, base_baud = 0) is a TEGRA_UART
[ 1.442556] 3140000.serial: ttyTHS4 at MMIO 0x3140000 (irq = 51, base_baud = 0) is a TEGRA_UART
[ 1.443210] 3150000.serial: ttyTHS5 at MMIO 0x3150000 (irq = 52, base_baud = 0) is a TEGRA_UART
[ 1.444184] c290000.serial: ttyTHS6 at MMIO 0xc290000 (irq = 53, base_baud = 0) is a TEGRA_UART
[ 1.444902] 3170000.serial: ttyTHS7 at MMIO 0x3170000 (irq = 54, base_baud = 0) is a TEGRA_UART
according to above info ,
THS0 =uarta=pr2/pr3=203/205 UART1_TX UART1_RX
THS2=uartc=pcc5/pcc6=236/238 UART3_TX UART3_RX
Since we design UART3 on pin header of our carrier board.
I open the terminal to output message to /dev/ttyTHS2 for test , and use oscilloscope to monitor UART3_TX signal. (pin236)
there are no any output signal , so as using rs232-usb cable with PC.
Is it any conflict pinmux setting on UART3 ? Or I miss other modification to make it work?