/**
* @file
*
* @ingroup arm_lpc32xx
*
* @brief High speed UART driver (14-clock).
*/
/*
* Copyright (c) 2010
* embedded brains GmbH
* Obere Lagerstr. 30
* D-82178 Puchheim
* Germany
* <rtems@embedded-brains.de>
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*/
#include <rtems.h>
#include <rtems/libio.h>
#include <rtems/termiostypes.h>
#include <libchip/serial.h>
#include <libchip/sersupp.h>
#include <bsp.h>
#include <bsp/lpc32xx.h>
#include <bsp/irq.h>
typedef struct {
uint32_t fifo;
uint32_t level;
uint32_t iir;
uint32_t ctrl;
uint32_t rate;
} lpc32xx_hsu;
#define HSU_FIFO_SIZE 64
#define HSU_LEVEL_RX_MASK 0xffU
#define HSU_LEVEL_TX_MASK 0xff00U
#define HSU_LEVEL_TX_SHIFT 8
#define HSU_RX_DATA_MASK 0xffU
#define HSU_RX_EMPTY (1U << 8)
#define HSU_RX_ERROR (1U << 9)
#define HSU_RX_BREAK (1U << 10)
#define HSU_IIR_TX (1U << 0)
#define HSU_IIR_RX_TRIG (1U << 1)
#define HSU_IIR_RX_TIMEOUT (1U << 2)
#define HSU_CTRL_INTR_DISABLED 0x1280fU
#define HSU_CTRL_RX_INTR_ENABLED 0x1284fU
#define HSU_CTRL_RX_AND_TX_INTR_ENABLED 0x1286fU
/* We are interested in RX timeout, RX trigger and TX trigger interrupts */
#define HSU_IIR_MASK 0x7U
static int lpc32xx_hsu_first_open(int major, int minor, void *arg)
{
rtems_libio_open_close_args_t *oca = arg;
struct rtems_termios_tty *tty = oca->iop->data1;
console_tbl *ct = Console_Port_Tbl [minor];
console_data *cd = &Console_Port_Data [minor];
volatile lpc32xx_hsu *hsu = (volatile lpc32xx_hsu *) ct->ulCtrlPort1;
cd->termios_data = tty;
rtems_termios_set_initial_baud(tty, (int32_t) ct->pDeviceParams);
hsu->ctrl = HSU_CTRL_RX_INTR_ENABLED;
return 0;
}
static ssize_t lpc32xx_hsu_write(int minor, const char *buf, size_t len)
{
console_tbl *ct = Console_Port_Tbl [minor];
console_data *cd = &Console_Port_Data [minor];
volatile lpc32xx_hsu *hsu = (volatile lpc32xx_hsu *) ct->ulCtrlPort1;
size_t tx_level = (hsu->level & HSU_LEVEL_TX_MASK) >> HSU_LEVEL_TX_SHIFT;
size_t tx_free = HSU_FIFO_SIZE - tx_level;
size_t i = 0;
size_t out = len > tx_free ? tx_free : len;
for (i = 0; i < out; ++i) {
hsu->fifo = buf [i];
}
if (len > 0) {
cd->pDeviceContext = (void *) out;
cd->bActive = true;
hsu->ctrl = HSU_CTRL_RX_AND_TX_INTR_ENABLED;
}
return 0;
}
static void lpc32xx_hsu_interrupt_handler(void *arg)
{
int minor = (int) arg;
console_tbl *ct = Console_Port_Tbl [minor];
console_data *cd = &Console_Port_Data [minor];
volatile lpc32xx_hsu *hsu = (volatile lpc32xx_hsu *) ct->ulCtrlPort1;
/* Iterate until no more interrupts are pending */
do {
int chars_to_dequeue = (int) cd->pDeviceContext;
int rv = 0;
int i = 0;
char buf [HSU_FIFO_SIZE];
/* Enqueue received characters */
while (i < HSU_FIFO_SIZE) {
uint32_t in = hsu->fifo;
if ((in & HSU_RX_EMPTY) == 0) {
if ((in & HSU_RX_BREAK) == 0) {
buf [i] = in & HSU_RX_DATA_MASK;
++i;
}
} else {
break;
}
}
rtems_termios_enqueue_raw_characters(cd->termios_data, buf, i);
/* Dequeue transmitted characters */
cd->pDeviceContext = 0;
rv = rtems_termios_dequeue_characters(cd->termios_data, chars_to_dequeue);
if (rv == 0) {
/* Nothing to transmit */
cd->bActive = false;
hsu->ctrl = HSU_CTRL_RX_INTR_ENABLED;
hsu->iir = HSU_IIR_TX;
}
} while ((hsu->iir & HSU_IIR_MASK) != 0);
}
static void lpc32xx_hsu_initialize(int minor)
{
console_tbl *ct = Console_Port_Tbl [minor];
console_data *cd = &Console_Port_Data [minor];
volatile lpc32xx_hsu *hsu = (volatile lpc32xx_hsu *) ct->ulCtrlPort1;
hsu->ctrl = HSU_CTRL_INTR_DISABLED;
cd->bActive = false;
cd->pDeviceContext = 0;
/* Drain FIFOs */
while (hsu->level != 0) {
hsu->fifo;
}
rtems_interrupt_handler_install(
ct->ulIntVector,
"HSU",
RTEMS_INTERRUPT_UNIQUE,
lpc32xx_hsu_interrupt_handler,
(void *) minor
);
}
static int lpc32xx_hsu_set_attributes(int minor, const struct termios *term)
{
console_tbl *ct = Console_Port_Tbl [minor];
volatile lpc32xx_hsu *hsu = (volatile lpc32xx_hsu *) ct->ulCtrlPort1;
int baud_flags = term->c_cflag & CBAUD;
if (baud_flags != 0) {
int32_t baud = rtems_termios_baud_to_number(baud_flags);
if (baud > 0) {
uint32_t baud_divisor = 14 * (uint32_t) baud;
uint32_t rate = LPC32XX_PERIPH_CLK / baud_divisor;
uint32_t remainder = LPC32XX_PERIPH_CLK - rate * baud_divisor;
if (2 * remainder >= baud_divisor) {
++rate;
}
hsu->rate = rate - 1;
}
}
return 0;
}
const console_fns lpc32xx_hsu_fns = {
.deviceProbe = libchip_serial_default_probe,
.deviceFirstOpen = lpc32xx_hsu_first_open,
.deviceLastClose = NULL,
.deviceRead = NULL,
.deviceWrite = lpc32xx_hsu_write,
.deviceInitialize = lpc32xx_hsu_initialize,
.deviceWritePolled = NULL,
.deviceSetAttributes = lpc32xx_hsu_set_attributes,
.deviceOutputUsesInterrupts = true
};