We are trying to set up UART1 on our board, which is based on LeopardBoard DM368, using the Appro IPNC SDK 4.x
I have followed the numerous posts on this forum which show how to setup UART1 via GIO25/GIO34 pins in the kernel, the steps are:
In /ipnc_psp_03_21_00_04/ti-davinci/arch/arm/mach-davinci/dm365.c
static struct clk uart0_clk = {
.name = "uart0",
.parent = &pll1_aux_clk,
.lpsc = DAVINCI_LPSC_UART0,
};
static struct clk uart1_clk = {
.name = "uart1",
.parent = &pll1_sysclk4,
.lpsc = DAVINCI_LPSC_UART1,
};
MUX_CFG(DM365, UART1_TXD, 3, 29, 3, 3, false) // GPIO 25 = UART1_TXD
MUX_CFG(DM365, UART1_RXD, 4, 14, 3, 3, false) // GPIO 34 = UART1_RXD
MUX_CFG(DM365, UART1_RTS, 3, 23, 3, 1, false)
MUX_CFG(DM365, UART1_CTS, 3, 21, 3, 1, false)
#define DM365_UART1_BASE (IO_PHYS + 0x106000)
static struct plat_serial8250_port dm365_serial_platform_data[] = {
{
.mapbase = DAVINCI_UART0_BASE,
.irq = IRQ_UARTINT0,
.flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST |
UPF_IOREMAP,
.iotype = UPIO_MEM,
.regshift = 2,
},
{
.mapbase = DM365_UART1_BASE,
.irq = IRQ_UARTINT1,
//.flags = UPF_IOREMAP,
.flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST |
UPF_IOREMAP,
.iotype = UPIO_MEM,
.regshift = 2,
},
{
.flags = 0
},
};
static struct platform_device dm365_serial_device = {
.name = "serial8250",
.id = PLAT8250_DEV_PLATFORM,
.dev = {
.platform_data = dm365_serial_platform_data,
},
};
In /ipnc_psp_03_21_00_04/ti-davinci/arch/arm/mach-davinci/board-dm368-ipnc.c
static struct davinci_uart_config uart_config __initdata = {
.enabled_uarts = (7 << 0),
};
dm368_evm_init() added:
davinci_cfg_reg(DM365_UART1_TXD);
davinci_cfg_reg(DM365_UART1_RXD);
davinci_cfg_reg(DM365_UART1_RTS);
davinci_cfg_reg(DM365_UART1_CTS);
Before the line davinci_serial_init(&uart_config);
In the boot process it shows the following:
[ 0.263546] davinci_serial_init: uart0 initialised
[ 0.274028] davinci_serial_init: uart1 initialised
[ 0.547812] serial8250.0: ttyS0 at MMIO 0x1c20000 (irq = 40) is a 16550A
[ 0.569849] serial8250.0: ttyS1 at MMIO 0x1d06000 (irq = 41) is a 16550A
If I do ls /dev/ I can see ttyS1, if I echo text to /dev/ttyS1 it returns OK but nothing happens (confirmed with oscillioscope), if I do cat /proc/tty/driver/serial
serinfo:1.0 driver revision:
0: uart:16550A mmio:0x01C20000 irq:40 tx:97998 rx:0 CTS|DSR
1: uart:16550A mmio:0x01D06000 irq:41 tx:0 rx:0 DSR
If I try to modify it I get an error:
> stty -F /dev/ttyS1
stty: /dev/ttyS1: Inappropriate ioctl for device
Here's the strange thing: If I modify bootargs to set the console to be ttyS1 (setenv bootargs 'console=ttyS1,115200n8 ....) UART1 works fine and reports:
cat /proc/tty/driver/serial
serinfo:1.0 driver revision:
0: uart:16550A mmio:0x01C20000 irq:40 tx:0 rx:0 CTS|DSR
1: uart:16550A mmio:0x01D06000 irq:41 tx:11563 rx:0 RTS|DTR|DSR
I notice the flow control flags seem to be set in a more sensible state (similar to UART0), it seems like the earlyprintk is doing a better job of initialising the port than the kernel. Can anyone tell me what I've missed or offer any hints?
