/* This file contains the driver for the GRLIB APBUART serial port. The driver
* is implemented by using the cons.c console layer. Interrupt/Polling/Task
* driven mode can be configured using driver resources:
*
* - mode (0=Polling, 1=Interrupt, 2=Task-Driven-Interrupt Mode)
* - syscon (0=Force not Ssystem Console, 1=Suggest System Console)
*
* The BSP define APBUART_INFO_AVAIL in order to add the info routine
* used for debugging.
*
* COPYRIGHT (c) 2010.
* Cobham Gaisler AB.
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
/******************* Driver manager interface ***********************/
#include <bsp.h>
#include <stdlib.h>
#include <assert.h>
#include <rtems/bspIo.h>
#include <string.h>
#include <stdio.h>
#include <drvmgr/drvmgr.h>
#include <grlib/ambapp_bus.h>
#include <grlib/apbuart.h>
#include <grlib/ambapp.h>
#include <grlib/grlib.h>
#include <grlib/cons.h>
#include <rtems/termiostypes.h>
#include <grlib/apbuart_cons.h>
/*#define DEBUG 1 */
#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif
/* LEON3 Low level transmit/receive functions provided by debug-uart code */
#ifdef LEON3
extern struct apbuart_regs *leon3_debug_uart; /* The debug UART */
#endif
/* Probed hardware capabilities */
enum {
CAP_FIFO = 0x01, /* FIFO available */
CAP_DI = 0x02, /* RX delayed interrupt available */
};
struct apbuart_priv {
struct console_dev condev;
struct drvmgr_dev *dev;
struct apbuart_regs *regs;
struct rtems_termios_tty *tty;
char devName[32];
volatile int sending;
int mode;
int cap;
};
/* Getters for different interfaces. It happens to be just casting which we do
* in one place to avoid getting cast away. */
static struct console_dev *base_get_condev(rtems_termios_device_context *base)
{
return (struct console_dev *) base;
}
static struct apbuart_priv *condev_get_priv(struct console_dev *condev)
{
return (struct apbuart_priv *) condev;
}
static struct apbuart_priv *base_get_priv(rtems_termios_device_context *base)
{
return condev_get_priv(base_get_condev(base));
}
/* TERMIOS Layer Callback functions */
static bool first_open(
rtems_termios_tty *tty,
rtems_termios_device_context *base,
struct termios *term,
rtems_libio_open_close_args_t *args
);
static void last_close(
rtems_termios_tty *tty,
rtems_termios_device_context *base,
rtems_libio_open_close_args_t *args
);
static void write_interrupt(
rtems_termios_device_context *base,
const char *buf,
size_t len
);
static bool set_attributes(
rtems_termios_device_context *base,
const struct termios *t
);
static void get_attributes(
rtems_termios_device_context *base,
struct termios *t
);
static int read_polled(rtems_termios_device_context *base);
static int read_task(rtems_termios_device_context *base);
static void write_polled(
rtems_termios_device_context *base,
const char *buf,
size_t len
);
static void apbuart_cons_isr(void *arg);
int apbuart_get_baud(struct apbuart_priv *uart);
int apbuart_init1(struct drvmgr_dev *dev);
#ifdef APBUART_INFO_AVAIL
static int apbuart_info(
struct drvmgr_dev *dev,
void (*print_line)(void *p, char *str),
void *p, int, char *argv[]);
#define APBUART_INFO_FUNC apbuart_info
#else
#define APBUART_INFO_FUNC NULL
#endif
struct drvmgr_drv_ops apbuart_ops =
{
.init = {apbuart_init1, NULL, NULL, NULL},
.remove = NULL,
.info = APBUART_INFO_FUNC
};
static struct amba_dev_id apbuart_ids[] =
{
{VENDOR_GAISLER, GAISLER_APBUART},
{0, 0} /* Mark end of table */
};
static struct amba_drv_info apbuart_drv_info =
{
{
DRVMGR_OBJ_DRV, /* Driver */
NULL, /* Next driver */
NULL, /* Device list */
DRIVER_AMBAPP_GAISLER_APBUART_ID, /* Driver ID */
"APBUART_DRV", /* Driver Name */
DRVMGR_BUS_TYPE_AMBAPP, /* Bus Type */
&apbuart_ops,
NULL, /* Funcs */
0, /* No devices yet */
sizeof(struct apbuart_priv), /*DrvMgr alloc private*/
},
&apbuart_ids[0]
};
void apbuart_cons_register_drv (void)
{
DBG("Registering APBUART Console driver\n");
drvmgr_drv_register(&apbuart_drv_info.general);
}
static const rtems_termios_device_handler handler_interrupt = {
.first_open = first_open,
.last_close = last_close,
.write = write_interrupt,
.set_attributes = set_attributes,
.mode = TERMIOS_IRQ_DRIVEN
};
static const rtems_termios_device_handler handler_task = {
.first_open = first_open,
.last_close = last_close,
.poll_read = read_task,
.write = write_interrupt,
.set_attributes = set_attributes,
.mode = TERMIOS_TASK_DRIVEN
};
static const rtems_termios_device_handler handler_polled = {
.first_open = first_open,
.last_close = last_close,
.poll_read = read_polled,
.write = write_polled,
.set_attributes = set_attributes,
.mode = TERMIOS_POLLED
};
/*
* APBUART hardware instantiation is flexible. Probe features here and driver
* can select appropriate routines for the hardware. probecap() return value
* is a CAP_ bitmask.
*/
static int probecap(struct apbuart_regs *regs)
{
int cap = 0;
/* Probe FIFO */
if (regs->ctrl & APBUART_CTRL_FA) {
cap |= CAP_FIFO;
/* Probe RX delayed interrupt */
regs->ctrl |= APBUART_CTRL_DI;
if (regs->ctrl & APBUART_CTRL_DI) {
regs->ctrl &= ~APBUART_CTRL_DI;
cap |= CAP_DI;
}
}
return cap;
}
int apbuart_init1(struct drvmgr_dev *dev)
{
struct apbuart_priv *priv;
struct amba_dev_info *ambadev;
struct ambapp_core *pnpinfo;
union drvmgr_key_value *value;
char prefix[32];
unsigned int db;
static int first_uart = 1;
/* The default operation in AMP is to use APBUART[0] for CPU[0],
* APBUART[1] for CPU[1] and so on. The remaining UARTs is not used
* since we don't know how many CPU-cores there are. Note this only
* affects the on-chip amba bus (the root bus). The user can override
* the default resource sharing by defining driver resources for the
* APBUART devices on each AMP OS instance.
*/
#if defined(RTEMS_MULTIPROCESSING) && defined(LEON3)
if (drvmgr_on_rootbus(dev) && dev->minor_drv != LEON3_Cpu_Index &&
drvmgr_keys_get(dev, NULL) != 0) {
/* User hasn't configured on-chip APBUART, leave it untouched */
return DRVMGR_EBUSY;
}
#endif
DBG("APBUART[%d] on bus %s\n", dev->minor_drv, dev->parent->dev->name);
/* Private data was allocated and zeroed by driver manager */
priv = dev->priv;
if (!priv)
return DRVMGR_NOMEM;
priv->dev = dev;
/* Get device information from AMBA PnP information */
ambadev = (struct amba_dev_info *)priv->dev->businfo;
if (ambadev == NULL)
return -1;
pnpinfo = &ambadev->info;
priv->regs = (struct apbuart_regs *)pnpinfo->apb_slv->start;
/* Clear HW regs, leave baudrate register as it is */
priv->regs->status = 0;
/* leave Transmitter/receiver if this is the RTEMS debug UART (assume
* it has been setup by boot loader).
*/
db = 0;
#ifdef LEON3
if (priv->regs == leon3_debug_uart) {
db = priv->regs->ctrl & (APBUART_CTRL_RE |
APBUART_CTRL_TE |
APBUART_CTRL_PE |
APBUART_CTRL_PS);
}
#endif
/* Let UART debug tunnelling be untouched if Flow-control is set.
*
* With old APBUARTs debug is enabled by setting LB and FL, since LB or
* DB are not reset we can not trust them. However since FL is reset we
* guess that we are debugging if FL is already set, the debugger set
* either LB or DB depending on UART capabilities.
*/
if (priv->regs->ctrl & APBUART_CTRL_FL) {
db |= priv->regs->ctrl & (APBUART_CTRL_DB |
APBUART_CTRL_LB | APBUART_CTRL_FL);
}
priv->regs->ctrl = db;
priv->cap = probecap(priv->regs);
/* The system console and Debug console may depend on this device, so
* initialize it straight away.
*
* We default to have System Console on first APBUART, user may override
* this behaviour by setting the syscon option to 0.
*/
if (drvmgr_on_rootbus(dev) && first_uart) {
priv->condev.flags = CONSOLE_FLAG_SYSCON;
first_uart = 0;
} else {
priv->condev.flags = 0;
}
value = drvmgr_dev_key_get(priv->dev, "syscon", DRVMGR_KT_INT);
if (value) {
if (value->i)
priv->condev.flags |= CONSOLE_FLAG_SYSCON;
else
priv->condev.flags &= ~CONSOLE_FLAG_SYSCON;
}
/* Select 0=Polled, 1=IRQ, 2=Task-Driven UART Mode */
value = drvmgr_dev_key_get(priv->dev, "mode", DRVMGR_KT_INT);
if (value)
priv->mode = value->i;
else
priv->mode = TERMIOS_POLLED;
/* TERMIOS device handlers */
if (priv->mode == TERMIOS_IRQ_DRIVEN) {
priv->condev.handler = &handler_interrupt;
} else if (priv->mode == TERMIOS_TASK_DRIVEN) {
priv->condev.handler = &handler_task;
} else {
priv->condev.handler = &handler_polled;
}
priv->condev.fsname = NULL;
/* Get Filesystem name prefix */
prefix[0] = '\0';
if (drvmgr_get_dev_prefix(dev, prefix) == DRVMGR_OK) {
/* Got special prefix, this means we have a bus prefix
* And we should use our "bus minor"
*/
sprintf(priv->devName, "/dev/%sapbuart%d", prefix, dev->minor_bus);
priv->condev.fsname = priv->devName;
} else {
sprintf(priv->devName, "/dev/apbuart%d", dev->minor_drv);
}
/* Register it as a console device, the console driver will register
* a termios device as well
*/
console_dev_register(&priv->condev);
return DRVMGR_OK;
}
#ifdef APBUART_INFO_AVAIL
static int apbuart_info(
struct drvmgr_dev *dev,
void (*print_line)(void *p, char *str),
void *p, int argc, char *argv[])
{
struct apbuart_priv *priv = dev->priv;
char *str1;
char buf[64];
if (dev->priv == NULL)
return -DRVMGR_EINVAL;
if (priv->mode == TERMIOS_POLLED)
str1 = "TERMIOS_POLLED";
else if (priv->mode == TERMIOS_IRQ_DRIVEN)
str1 = "TERMIOS_IRQ_DRIVEN";
else if (priv->mode == TERMIOS_TASK_DRIVEN)
str1 = "TERMIOS_TASK_DRIVEN";
else
str1 = "BAD MODE";
sprintf(buf, "UART Mode: %s", str1);
print_line(p, buf);
if (priv->condev.fsname) {
sprintf(buf, "FS Name: %s", priv->condev.fsname);
print_line(p, buf);
}
sprintf(buf, "STATUS REG: 0x%x", priv->regs->status);
print_line(p, buf);
sprintf(buf, "CTRL REG: 0x%x", priv->regs->ctrl);
print_line(p, buf);
sprintf(buf, "SCALER REG: 0x%x baud rate %d",
priv->regs->scaler, apbuart_get_baud(priv));
print_line(p, buf);
return DRVMGR_OK;
}
#endif
static bool first_open(
rtems_termios_tty *tty,
rtems_termios_device_context *base,
struct termios *term,
rtems_libio_open_close_args_t *args
)
{
struct apbuart_priv *uart = base_get_priv(base);
uart->tty = tty;
/* Inherit UART hardware parameters from bootloader on system console */
if (uart->condev.flags & CONSOLE_FLAG_SYSCON_GRANT) {
get_attributes(base, term);
term->c_oflag |= ONLCR;
set_attributes(base, term);
}
/* Enable TX/RX */
uart->regs->ctrl |= APBUART_CTRL_RE | APBUART_CTRL_TE;
if (uart->mode != TERMIOS_POLLED) {
int ret;
uint32_t ctrl;
/* Register interrupt and enable it */
ret = drvmgr_interrupt_register(
uart->dev, 0, uart->devName, apbuart_cons_isr, tty
);
if (ret) {
return false;
}
uart->sending = 0;
/* Turn on RX interrupts */
ctrl = uart->regs->ctrl;
ctrl |= APBUART_CTRL_RI;
if (uart->cap & CAP_DI) {
/* Use RX FIFO interrupt only if delayed interrupt available. */
ctrl |= (APBUART_CTRL_DI | APBUART_CTRL_RF);
}
uart->regs->ctrl = ctrl;
}
return true;
}
static void last_close(
rtems_termios_tty *tty,
rtems_termios_device_context *base,
rtems_libio_open_close_args_t *args
)
{
struct apbuart_priv *uart = base_get_priv(base);
rtems_interrupt_lock_context lock_context;
if (uart->mode != TERMIOS_POLLED) {
/* Turn off RX interrupts */
rtems_termios_device_lock_acquire(base, &lock_context);
uart->regs->ctrl &=
~(APBUART_CTRL_DI | APBUART_CTRL_RI | APBUART_CTRL_RF);
rtems_termios_device_lock_release(base, &lock_context);
/**** Flush device ****/
while (uart->sending) {
/* Wait until all data has been sent */
}
while (
(uart->regs->ctrl & APBUART_CTRL_TE) &&
!(uart->regs->status & APBUART_STATUS_TS)
) {
/* Wait until all data has left shift register */
}
/* Disable and unregister interrupt handler */
drvmgr_interrupt_unregister(uart->dev, 0, apbuart_cons_isr, tty);
}
#ifdef LEON3
/* Disable TX/RX if not used for DEBUG */
if (uart->regs != leon3_debug_uart)
uart->regs->ctrl &= ~(APBUART_CTRL_RE | APBUART_CTRL_TE);
#endif
}
static int read_polled(rtems_termios_device_context *base)
{
struct apbuart_priv *uart = base_get_priv(base);
return apbuart_inbyte_nonblocking(uart->regs);
}
/* This function is called from TERMIOS rxdaemon task without device lock. */
static int read_task(rtems_termios_device_context *base)
{
rtems_interrupt_lock_context lock_context;
struct apbuart_priv *uart = base_get_priv(base);
struct apbuart_regs *regs = uart->regs;
int cnt;
char buf[33];
struct rtems_termios_tty *tty;
uint32_t ctrl_add;
ctrl_add = APBUART_CTRL_RI;
if (uart->cap & CAP_DI) {
ctrl_add |= (APBUART_CTRL_DI | APBUART_CTRL_RF);
}
tty = uart->tty;
do {
cnt = 0;
while (
(regs->status & APBUART_STATUS_DR) &&
(cnt < sizeof(buf))
) {
buf[cnt] = regs->data;
cnt++;
}
if (0 < cnt) {
/* Tell termios layer about new characters */
rtems_termios_enqueue_raw_characters(tty, &buf[0], cnt);
}
/*
* Turn on RX interrupts. A new character in FIFO now may not
* cause interrupt so we must check data ready again
* afterwards.
*/
rtems_termios_device_lock_acquire(base, &lock_context);
regs->ctrl |= ctrl_add;
rtems_termios_device_lock_release(base, &lock_context);
} while (regs->status & APBUART_STATUS_DR);
return EOF;
}
int apbuart_get_baud(struct apbuart_priv *uart)
{
unsigned int core_clk_hz;
unsigned int scaler;
/* Get current scaler setting */
scaler = uart->regs->scaler;
/* Get APBUART core frequency */
drvmgr_freq_get(uart->dev, DEV_APB_SLV, &core_clk_hz);
/* Calculate baud rate from generator "scaler" number */
return core_clk_hz / ((scaler + 1) * 8);
}
static bool set_attributes(
rtems_termios_device_context *base,
const struct termios *t
)
{
unsigned int core_clk_hz;
unsigned int scaler;
unsigned int ctrl;
int baud;
struct apbuart_priv *uart = base_get_priv(base);
rtems_interrupt_lock_context lock_context;
switch(t->c_cflag & CSIZE) {
default:
case CS5:
case CS6:
case CS7:
/* Hardware doesn't support other than CS8 */
return false;
case CS8:
break;
}
rtems_termios_device_lock_acquire(base, &lock_context);
/* Read out current value */
ctrl = uart->regs->ctrl;
switch(t->c_cflag & (PARENB|PARODD)){
case (PARENB|PARODD):
/* Odd parity */
ctrl |= APBUART_CTRL_PE|APBUART_CTRL_PS;
break;
case PARENB:
/* Even parity */
ctrl &= ~APBUART_CTRL_PS;
ctrl |= APBUART_CTRL_PE;
break;
default:
case 0:
case PARODD:
/* No Parity */
ctrl &= ~(APBUART_CTRL_PS|APBUART_CTRL_PE);
}
if (!(t->c_cflag & CLOCAL))
ctrl |= APBUART_CTRL_FL;
else
ctrl &= ~APBUART_CTRL_FL;
/* Update new settings */
uart->regs->ctrl = ctrl;
rtems_termios_device_lock_release(base, &lock_context);
/* Baud rate */
baud = rtems_termios_baud_to_number(t->c_ospeed);
if (baud > 0){
/* Get APBUART core frequency */
drvmgr_freq_get(uart->dev, DEV_APB_SLV, &core_clk_hz);
/* Calculate Baud rate generator "scaler" number */
scaler = (((core_clk_hz*10)/(baud*8))-5)/10;
/* Set new baud rate by setting scaler */
uart->regs->scaler = scaler;
}
return true;
}
static void get_attributes(
rtems_termios_device_context *base,
struct termios *t
)
{
struct apbuart_priv *uart = base_get_priv(base);
unsigned int ctrl;
t->c_cflag = t->c_cflag & ~(CSIZE|PARENB|PARODD|CLOCAL);
/* Hardware support only CS8 */
t->c_cflag |= CS8;
/* Read out current parity */
ctrl = uart->regs->ctrl;
if (ctrl & APBUART_CTRL_PE) {
if (ctrl & APBUART_CTRL_PS)
t->c_cflag |= PARENB|PARODD; /* Odd parity */
else
t->c_cflag |= PARENB; /* Even parity */
}
if ((ctrl & APBUART_CTRL_FL) == 0)
t->c_cflag |= CLOCAL;
rtems_termios_set_best_baud(t, apbuart_get_baud(uart));
}
static void write_polled(
rtems_termios_device_context *base,
const char *buf,
size_t len
)
{
struct apbuart_priv *uart = base_get_priv(base);
int nwrite = 0;
while (nwrite < len) {
apbuart_outbyte_polled(uart->regs, *buf++);
nwrite++;
}
}
static void write_interrupt(
rtems_termios_device_context *base,
const char *buf,
size_t len
)
{
struct apbuart_priv *uart = base_get_priv(base);
struct apbuart_regs *regs = uart->regs;
int sending;
unsigned int ctrl;
ctrl = regs->ctrl;
if (len > 0) {
/*
* sending is used to remember how much we have outstanding so
* we can tell termios later.
*/
/* Enable TX interrupt (interrupt is edge-triggered) */
regs->ctrl = ctrl | APBUART_CTRL_TI;
if (ctrl & APBUART_CTRL_FA) {
/* APBUART with FIFO.. Fill as many as FIFO allows */
sending = 0;
while (
((regs->status & APBUART_STATUS_TF) == 0) &&
(sending < len)
) {
regs->data = *buf;
buf++;
sending++;
}
} else {
/* start UART TX, this will result in an interrupt when done */
regs->data = *buf;
sending = 1;
}
} else {
/* No more to send, disable TX interrupts */
regs->ctrl = ctrl & ~APBUART_CTRL_TI;
/* Tell close that we sent everything */
sending = 0;
}
uart->sending = sending;
}
/* Handle UART interrupts */
static void apbuart_cons_isr(void *arg)
{
rtems_termios_tty *tty = arg;
rtems_termios_device_context *base;
struct console_dev *condev = rtems_termios_get_device_context(tty);
struct apbuart_priv *uart = condev_get_priv(condev);
struct apbuart_regs *regs = uart->regs;
unsigned int status;
char buf[33];
int cnt;
if (uart->mode == TERMIOS_TASK_DRIVEN) {
if ((status = regs->status) & APBUART_STATUS_DR) {
rtems_interrupt_lock_context lock_context;
/* Turn off RX interrupts */
base = rtems_termios_get_device_context(tty);
rtems_termios_device_lock_acquire(base, &lock_context);
regs->ctrl &=
~(APBUART_CTRL_DI | APBUART_CTRL_RI |
APBUART_CTRL_RF);
rtems_termios_device_lock_release(base, &lock_context);
/* Activate termios RX daemon task */
rtems_termios_rxirq_occured(tty);
}
} else {
/*
* Get all new characters from APBUART RX (FIFO) and store them
* on the stack. Then tell termios about the new characters.
* Maximum APBUART RX FIFO size is 32 characters.
*/
cnt = 0;
while (
((status=regs->status) & APBUART_STATUS_DR) &&
(cnt < sizeof(buf))
) {
buf[cnt] = regs->data;
cnt++;
}
if (0 < cnt) {
/* Tell termios layer about new characters */
rtems_termios_enqueue_raw_characters(tty, &buf[0], cnt);
}
}
if (uart->sending && (status & APBUART_STATUS_TE)) {
/* Tell close that we sent everything */
cnt = uart->sending;
/*
* Tell termios how much we have sent. dequeue() may call
* write_interrupt() to refill the transmitter.
* write_interrupt() will eventually be called with 0 len to
* disable TX interrupts.
*/
rtems_termios_dequeue_characters(tty, cnt);
}
}