static void bfin_serial_rx_chars(struct bfin_serial_port *uart)
{
struct tty_struct *tty = NULL;
unsigned int status, ch, flg;
static struct timeval anomaly_start = { .tv_sec = 0 };
status = UART_GET_LSR(uart);
UART_CLEAR_LSR(uart);
ch = UART_GET_CHAR(uart);
uart->port.icount.rx++;
#if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
if (kgdb_connected && kgdboc_port_line == uart->port.line
&& kgdboc_break_enabled)
if (ch == 0x3) {/* Ctrl + C */
kgdb_breakpoint();
return;
}
if (!uart->port.state || !uart->port.state->port.tty)
return;
#endif
tty = uart->port.state->port.tty;
if (ANOMALY_05000363) {
/* The BF533 (and BF561) family of processors have a nice anomaly
* where they continuously generate characters for a "single" break.
* We have to basically ignore this flood until the "next" valid
* character comes across. Due to the nature of the flood, it is
* not possible to reliably catch bytes that are sent too quickly
* after this break. So application code talking to the Blackfin
* which sends a break signal must allow at least 1.5 character
* times after the end of the break for things to stabilize. This
* timeout was picked as it must absolutely be larger than 1
* character time +/- some percent. So 1.5 sounds good. All other
* Blackfin families operate properly. Woo.
*/
if (anomaly_start.tv_sec) {
struct timeval curr;
suseconds_t usecs;
if ((~ch & (~ch + 1)) & 0xff)
goto known_good_char;
do_gettimeofday(&curr);
if (curr.tv_sec - anomaly_start.tv_sec > 1)
goto known_good_char;
usecs = 0;
if (curr.tv_sec != anomaly_start.tv_sec)
usecs += USEC_PER_SEC;
usecs += curr.tv_usec - anomaly_start.tv_usec;
if (usecs > UART_GET_ANOMALY_THRESHOLD(uart))
goto known_good_char;
if (ch)
anomaly_start.tv_sec = 0;
else
anomaly_start = curr;
return;
known_good_char:
status &= ~BI;
anomaly_start.tv_sec = 0;
}
}
if (status & BI) {
if (ANOMALY_05000363)
if (bfin_revid() < 5)
do_gettimeofday(&anomaly_start);
uart->port.icount.brk++;
if (uart_handle_break(&uart->port))
goto ignore_char;
status &= ~(PE | FE);
}
if (status & PE)
uart->port.icount.parity++;
if (status & OE)
uart->port.icount.overrun++;
if (status & FE)
uart->port.icount.frame++;
status &= uart->port.read_status_mask;
if (status & BI)
flg = TTY_BREAK;
else if (status & PE)
flg = TTY_PARITY;
else if (status & FE)
flg = TTY_FRAME;
else
flg = TTY_NORMAL;
if (uart_handle_sysrq_char(&uart->port, ch))
goto ignore_char;
uart_insert_char(&uart->port, status, OE, ch, flg);
ignore_char:
tty_flip_buffer_push(tty);
}
static void bfin_serial_tx_chars(struct bfin_serial_port *uart)
{
struct circ_buf *xmit = &uart->port.state->xmit;
if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
#ifdef CONFIG_BF54x
/* Clear TFI bit */
UART_PUT_LSR(uart, TFI);
#endif
/* Anomaly notes:
* 05000215 - we always clear ETBEI within last UART TX
* interrupt to end a string. It is always set
* when start a new tx.
*/
UART_CLEAR_IER(uart, ETBEI);
return;
}
if (uart->port.x_char) {
UART_PUT_CHAR(uart, uart->port.x_char);
uart->port.icount.tx++;
uart->port.x_char = 0;
}
while ((UART_GET_LSR(uart) & THRE) && xmit->tail != xmit->head) {
UART_PUT_CHAR(uart, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
uart->port.icount.tx++;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&uart->port);
}
static irqreturn_t bfin_serial_rx_int(int irq, void *dev_id)
{
struct bfin_serial_port *uart = dev_id;
while (UART_GET_LSR(uart) & DR)
bfin_serial_rx_chars(uart);
return IRQ_HANDLED;
}
static irqreturn_t bfin_serial_tx_int(int irq, void *dev_id)
{
struct bfin_serial_port *uart = dev_id;
#ifdef CONFIG_SERIAL_BFIN_HARD_CTSRTS
if (uart->scts && !(bfin_serial_get_mctrl(&uart->port) & TIOCM_CTS)) {
uart->scts = 0;
uart_handle_cts_change(&uart->port, uart->scts);
}
#endif
spin_lock(&uart->port.lock);
if (UART_GET_LSR(uart) & THRE)
bfin_serial_tx_chars(uart);
spin_unlock(&uart->port.lock);
return IRQ_HANDLED;
}
#endif
#ifdef CONFIG_SERIAL_BFIN_DMA
static void bfin_serial_dma_tx_chars(struct bfin_serial_port *uart)
{
struct circ_buf *xmit = &uart->port.state->xmit;
uart->tx_done = 0;
if (uart_circ_empty(xmit) || uart_tx_stopped(&uart->port)) {
uart->tx_count = 0;
uart->tx_done = 1;
return;
}
if (uart->port.x_char) {
UART_PUT_CHAR(uart, uart->port.x_char);
uart->port.icount.tx++;
uart->port.x_char = 0;
}
uart->tx_count = CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE);
if (uart->tx_count > (UART_XMIT_SIZE - xmit->tail))
uart->tx_count = UART_XMIT_SIZE - xmit->tail;
blackfin_dcache_flush_range((unsigned long)(xmit->buf+xmit->tail),
(unsigned long)(xmit->buf+xmit->tail+uart->tx_count));
set_dma_config(uart->tx_dma_channel,
set_bfin_dma_config(DIR_READ, DMA_FLOW_STOP,
INTR_ON_BUF,
DIMENSION_LINEAR,
DATA_SIZE_8,
DMA_SYNC_RESTART));
set_dma_start_addr(uart->tx_dma_channel, (unsigned long)(xmit->buf+xmit->tail));
set_dma_x_count(uart->tx_dma_channel, uart->tx_count);
set_dma_x_modify(uart->tx_dma_channel, 1);
SSYNC();
enable_dma(uart->tx_dma_channel);
UART_SET_IER(uart, ETBEI);
}
static void bfin_serial_dma_rx_chars(struct bfin_serial_port *uart)
{
struct tty_struct *tty = uart->port.state->port.tty;
int i, flg, status;
status = UART_GET_LSR(uart);
UART_CLEAR_LSR(uart);
uart->port.icount.rx +=
CIRC_CNT(uart->rx_dma_buf.head, uart->rx_dma_buf.tail,
UART_XMIT_SIZE);
if (status & BI) {
uart->port.icount.brk++;
if (uart_handle_break(&uart->port))
goto dma_ignore_char;
status &= ~(PE | FE);
}
if (status & PE)
uart->port.icount.parity++;
if (status & OE)
uart->port.icount.overrun++;
if (status & FE)
uart->port.icount.frame++;
status &= uart->port.read_status_mask;
if (status & BI)
flg = TTY_BREAK;
else if (status & PE)
flg = TTY_PARITY;
else if (status & FE)
flg = TTY_FRAME;
else
flg = TTY_NORMAL;
for (i = uart->rx_dma_buf.tail; ; i++) {
if (i >= UART_XMIT_SIZE)
i = 0;
if (i == uart->rx_dma_buf.head)
break;
if (!uart_handle_sysrq_char(&uart->port, uart->rx_dma_buf.buf[i]))
uart_insert_char(&uart->port, status, OE,
uart->rx_dma_buf.buf[i], flg);
}
dma_ignore_char:
tty_flip_buffer_push(tty);
}
void bfin_serial_rx_dma_timeout(struct bfin_serial_port *uart)
{
int x_pos, pos;
dma_disable_irq_nosync(uart->rx_dma_channel);
spin_lock_bh(&uart->rx_lock);
/* 2D DMA RX buffer ring is used. Because curr_y_count and
* curr_x_count can't be read as an atomic operation,
* curr_y_count should be read before curr_x_count. When
* curr_x_count is read, curr_y_count may already indicate
* next buffer line. But, the position calculated here is
* still indicate the old line. The wrong position data may
* be smaller than current buffer tail, which cause garbages
* are received if it is not prohibit.
*/
uart->rx_dma_nrows = get_dma_curr_ycount(uart->rx_dma_channel);
x_pos = get_dma_curr_xcount(uart->rx_dma_channel);
uart->rx_dma_nrows = DMA_RX_YCOUNT - uart->rx_dma_nrows;
if (uart->rx_dma_nrows == DMA_RX_YCOUNT || x_pos == 0)
uart->rx_dma_nrows = 0;
x_pos = DMA_RX_XCOUNT - x_pos;
if (x_pos == DMA_RX_XCOUNT)
x_pos = 0;
pos = uart->rx_dma_nrows * DMA_RX_XCOUNT + x_pos;
/* Ignore receiving data if new position is in the same line of
* current buffer tail and small.
*/
if (pos > uart->rx_dma_buf.tail ||
uart->rx_dma_nrows < (uart->rx_dma_buf.tail/DMA_RX_XCOUNT)) {
uart->rx_dma_buf.head = pos;
bfin_serial_dma_rx_chars(uart);
uart->rx_dma_buf.tail = uart->rx_dma_buf.head;
}
spin_unlock_bh(&uart->rx_lock);
dma_enable_irq(uart->rx_dma_channel);
mod_timer(&(uart->rx_dma_timer), jiffies + DMA_RX_FLUSH_JIFFIES);
}
static int bfin_serial_startup(struct uart_port *port)
{
struct bfin_serial_port *uart = (struct bfin_serial_port *)port;
#ifdef CONFIG_SERIAL_BFIN_DMA
dma_addr_t dma_handle;
if (request_dma(uart->rx_dma_channel, "BFIN_UART_RX") < 0) {
printk(KERN_NOTICE "Unable to attach Blackfin UART RX DMA channel\n");
return -EBUSY;
}
if (request_dma(uart->tx_dma_channel, "BFIN_UART_TX") < 0) {
printk(KERN_NOTICE "Unable to attach Blackfin UART TX DMA channel\n");
free_dma(uart->rx_dma_channel);
return -EBUSY;
}
set_dma_callback(uart->rx_dma_channel, bfin_serial_dma_rx_int, uart);
set_dma_callback(uart->tx_dma_channel, bfin_serial_dma_tx_int, uart);
uart->rx_dma_buf.buf = (unsigned char *)dma_alloc_coherent(NULL, PAGE_SIZE, &dma_handle, GFP_DMA);
uart->rx_dma_buf.head = 0;
uart->rx_dma_buf.tail = 0;
uart->rx_dma_nrows = 0;
set_dma_config(uart->rx_dma_channel,
set_bfin_dma_config(DIR_WRITE, DMA_FLOW_AUTO,
INTR_ON_ROW, DIMENSION_2D,
DATA_SIZE_8,
DMA_SYNC_RESTART));
set_dma_x_count(uart->rx_dma_channel, DMA_RX_XCOUNT);
set_dma_x_modify(uart->rx_dma_channel, 1);
set_dma_y_count(uart->rx_dma_channel, DMA_RX_YCOUNT);
set_dma_y_modify(uart->rx_dma_channel, 1);
set_dma_start_addr(uart->rx_dma_channel, (unsigned long)uart->rx_dma_buf.buf);
enable_dma(uart->rx_dma_channel);
uart->rx_dma_timer.data = (unsigned long)(uart);
uart->rx_dma_timer.function = (void *)bfin_serial_rx_dma_timeout;
uart->rx_dma_timer.expires = jiffies + DMA_RX_FLUSH_JIFFIES;
add_timer(&(uart->rx_dma_timer));
#else
# if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
if (kgdboc_port_line == uart->port.line && kgdboc_break_enabled)
kgdboc_break_enabled = 0;
else {
# endif
if (request_irq(uart->port.irq, bfin_serial_rx_int, IRQF_DISABLED,
"BFIN_UART_RX", uart)) {
printk(KERN_NOTICE "Unable to attach BlackFin UART RX interrupt\n");
return -EBUSY;
}
if (request_irq
(uart->port.irq+1, bfin_serial_tx_int, IRQF_DISABLED,
"BFIN_UART_TX", uart)) {
printk(KERN_NOTICE "Unable to attach BlackFin UART TX interrupt\n");
free_irq(uart->port.irq, uart);
return -EBUSY;
}
# ifdef CONFIG_BF54x
{
unsigned uart_dma_ch_rx, uart_dma_ch_tx;
switch (uart->port.irq) {
case IRQ_UART3_RX:
uart_dma_ch_rx = CH_UART3_RX;
uart_dma_ch_tx = CH_UART3_TX;
break;
case IRQ_UART2_RX:
uart_dma_ch_rx = CH_UART2_RX;
uart_dma_ch_tx = CH_UART2_TX;
break;
default:
uart_dma_ch_rx = uart_dma_ch_tx = 0;
break;
};
if (uart_dma_ch_rx &&
request_dma(uart_dma_ch_rx, "BFIN_UART_RX") < 0) {
printk(KERN_NOTICE"Fail to attach UART interrupt\n");
free_irq(uart->port.irq, uart);
free_irq(uart->port.irq + 1, uart);
return -EBUSY;
}
if (uart_dma_ch_tx &&
request_dma(uart_dma_ch_tx, "BFIN_UART_TX") < 0) {
printk(KERN_NOTICE "Fail to attach UART interrupt\n");
free_dma(uart_dma_ch_rx);
free_irq(uart->port.irq, uart);
free_irq(uart->port.irq + 1, uart);
return -EBUSY;
}
}
# endif
# if defined(CONFIG_KGDB_SERIAL_CONSOLE) || \
defined(CONFIG_KGDB_SERIAL_CONSOLE_MODULE)
}
# endif
#endif
#ifdef CONFIG_SERIAL_BFIN_CTSRTS
if (uart->cts_pin >= 0) {
if (request_irq(gpio_to_irq(uart->cts_pin),
bfin_serial_mctrl_cts_int,
IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING |
IRQF_DISABLED, "BFIN_UART_CTS", uart)) {
uart->cts_pin = -1;
pr_info("Unable to attach BlackFin UART CTS interrupt.\
So, disable it.\n");
}
}
