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Flesh out imx_uart_init() so that we're not relying on u-boot to init

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the hardware (meaning uarts other than the console will work).
This commit is contained in:
ian 2014-04-26 20:03:04 +00:00
parent 044b3e1a2f
commit c08e3d03ca
1 changed files with 73 additions and 2 deletions
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75
sys/dev/uart/uart_dev_imx.c
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@ -43,10 +43,11 @@ __FBSDID("$FreeBSD$");
#include <dev/uart/uart.h>
#include <dev/uart/uart_cpu.h>
#include <dev/uart/uart_bus.h>
#include <dev/uart/uart_dev_imx.h>
#include "uart_if.h"
#include <arm/freescale/imx/imx_ccmvar.h>
/*
* Low-level UART interface.
*/
@ -66,6 +67,22 @@ static struct uart_ops uart_imx_uart_ops = {
.getc = imx_uart_getc,
};
#if 0 /* Handy when debugging. */
static void
dumpregs(struct uart_bas *bas, const char * msg)
{
if (!bootverbose)
return;
printf("%s bsh 0x%08lx UCR1 0x%08x UCR2 0x%08x "
"UCR3 0x%08x UCR4 0x%08x USR1 0x%08x USR2 0x%08x\n",
msg, bas->bsh,
GETREG(bas, REG(UCR1)), GETREG(bas, REG(UCR2)),
GETREG(bas, REG(UCR3)), GETREG(bas, REG(UCR4)),
GETREG(bas, REG(USR1)), GETREG(bas, REG(USR2)));
}
#endif
static int
imx_uart_probe(struct uart_bas *bas)
{
@ -77,7 +94,59 @@ static void
imx_uart_init(struct uart_bas *bas, int baudrate, int databits,
int stopbits, int parity)
{
uint32_t baseclk, reg;
/* Enable the device and the RX/TX channels. */
SET(bas, REG(UCR1), FLD(UCR1, UARTEN));
SET(bas, REG(UCR2), FLD(UCR2, RXEN) | FLD(UCR2, TXEN));
if (databits == 7)
DIS(bas, UCR2, WS);
else
ENA(bas, UCR2, WS);
if (stopbits == 2)
ENA(bas, UCR2, STPB);
else
DIS(bas, UCR2, STPB);
switch (parity) {
case UART_PARITY_ODD:
DIS(bas, UCR2, PROE);
ENA(bas, UCR2, PREN);
break;
case UART_PARITY_EVEN:
ENA(bas, UCR2, PROE);
ENA(bas, UCR2, PREN);
break;
case UART_PARITY_MARK:
case UART_PARITY_SPACE:
/* FALLTHROUGH: Hardware doesn't support mark/space. */
case UART_PARITY_NONE:
default:
DIS(bas, UCR2, PREN);
break;
}
/*
* The hardware has an extremely flexible baud clock: it allows setting
* both the numerator and denominator of the divider, as well as a
* separate pre-divider. We simplify that problem by assuming a
* pre-divider and numerator of one because our base clock is so fast we
* can reach virtually any reasonable speed with a simple divisor. The
* numerator value actually includes the 16x over-sampling; the register
* value is the numerator-1, so we have a hard-coded 15. Note that a
* quirk of the hardware requires that both UBIR and UBMR be set back to
* back in order for the change to take effect.
*/
if (baudrate > 0) {
baseclk = imx_ccm_uart_hz();
reg = GETREG(bas, REG(UFCR));
reg = (reg & ~IMXUART_UFCR_RFDIV_MASK) | IMXUART_UFCR_RFDIV_DIV1;
SETREG(bas, REG(UFCR), reg);
SETREG(bas, REG(UBIR), 15);
SETREG(bas, REG(UBMR), (baseclk / baudrate) - 1);
}
}
static void
@ -218,6 +287,8 @@ imx_uart_bus_attach(struct uart_softc *sc)
DIS(bas, UCR3, RI);
DIS(bas, UCR3, DCD);
DIS(bas, UCR3, DTRDEN);
ENA(bas, UCR2, IRTS);
ENA(bas, UCR3, RXDMUXSEL);
/* ACK all interrupts */
SETREG(bas, REG(USR1), 0xffff);