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yaml
---
r: 191588
b: refs/heads/master
c: 3089f38
h: refs/heads/master
v: v3
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Guennadi Liakhovetski authored and Paul Mundt committed Mar 23, 2010
1 parent 8c597fa commit df5abc6
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Showing 2 changed files with 82 additions and 34 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: b2623a61cfd3c6badb8396dc85ab5a70f4a05f61
refs/heads/master: 3089f381fbaf53560dcbcb4aef6ef17fe44e347c
114 changes: 81 additions & 33 deletions trunk/drivers/serial/sh-sci.c
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Original file line number Diff line number Diff line change
Expand Up @@ -106,6 +106,7 @@ struct sci_port {
struct work_struct work_tx;
struct work_struct work_rx;
struct timer_list rx_timer;
unsigned int rx_timeout;
#endif
};

Expand Down Expand Up @@ -673,22 +674,22 @@ static irqreturn_t sci_rx_interrupt(int irq, void *ptr)
struct sci_port *s = to_sci_port(port);

if (s->chan_rx) {
unsigned long tout;
u16 scr = sci_in(port, SCSCR);
u16 ssr = sci_in(port, SCxSR);

/* Disable future Rx interrupts */
sci_out(port, SCSCR, scr & ~SCI_CTRL_FLAGS_RIE);
if (port->type == PORT_SCIFA) {
disable_irq_nosync(irq);
scr |= 0x4000;
} else {
scr &= ~SCI_CTRL_FLAGS_RIE;
}
sci_out(port, SCSCR, scr);
/* Clear current interrupt */
sci_out(port, SCxSR, ssr & ~(1 | SCxSR_RDxF(port)));
/* Calculate delay for 1.5 DMA buffers */
tout = (port->timeout - HZ / 50) * s->buf_len_rx * 3 /
port->fifosize / 2;
dev_dbg(port->dev, "Rx IRQ: setup timeout in %lu ms\n",
tout * 1000 / HZ);
if (tout < 2)
tout = 2;
mod_timer(&s->rx_timer, jiffies + tout);
dev_dbg(port->dev, "Rx IRQ %lu: setup t-out in %u jiffies\n",
jiffies, s->rx_timeout);
mod_timer(&s->rx_timer, jiffies + s->rx_timeout);

return IRQ_HANDLED;
}
Expand Down Expand Up @@ -925,13 +926,17 @@ static void sci_dma_tx_complete(void *arg)
s->cookie_tx = -EINVAL;
s->desc_tx = NULL;

spin_unlock_irqrestore(&port->lock, flags);

if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);

if (uart_circ_chars_pending(xmit))
if (!uart_circ_empty(xmit)) {
schedule_work(&s->work_tx);
} else if (port->type == PORT_SCIFA) {
u16 ctrl = sci_in(port, SCSCR);
sci_out(port, SCSCR, ctrl & ~SCI_CTRL_FLAGS_TIE);
}

spin_unlock_irqrestore(&port->lock, flags);
}

/* Locking: called with port lock held */
Expand Down Expand Up @@ -975,13 +980,13 @@ static void sci_dma_rx_complete(void *arg)
unsigned long flags;
int count;

dev_dbg(port->dev, "%s(%d)\n", __func__, port->line);
dev_dbg(port->dev, "%s(%d) active #%d\n", __func__, port->line, s->active_rx);

spin_lock_irqsave(&port->lock, flags);

count = sci_dma_rx_push(s, tty, s->buf_len_rx);

mod_timer(&s->rx_timer, jiffies + msecs_to_jiffies(5));
mod_timer(&s->rx_timer, jiffies + s->rx_timeout);

spin_unlock_irqrestore(&port->lock, flags);

Expand Down Expand Up @@ -1053,6 +1058,8 @@ static void sci_submit_rx(struct sci_port *s)
sci_rx_dma_release(s, true);
return;
}
dev_dbg(s->port.dev, "%s(): cookie %d to #%d\n", __func__,
s->cookie_rx[i], i);
}

s->active_rx = s->cookie_rx[0];
Expand Down Expand Up @@ -1110,10 +1117,10 @@ static void work_fn_rx(struct work_struct *work)
return;
}

dev_dbg(port->dev, "%s: cookie %d #%d\n", __func__,
s->cookie_rx[new], new);

s->active_rx = s->cookie_rx[!new];

dev_dbg(port->dev, "%s: cookie %d #%d, new active #%d\n", __func__,
s->cookie_rx[new], new, s->active_rx);
}

static void work_fn_tx(struct work_struct *work)
Expand Down Expand Up @@ -1175,23 +1182,28 @@ static void work_fn_tx(struct work_struct *work)

static void sci_start_tx(struct uart_port *port)
{
struct sci_port *s = to_sci_port(port);
unsigned short ctrl;

#ifdef CONFIG_SERIAL_SH_SCI_DMA
struct sci_port *s = to_sci_port(port);

if (s->chan_tx) {
if (!uart_circ_empty(&s->port.state->xmit) && s->cookie_tx < 0)
schedule_work(&s->work_tx);

return;
if (port->type == PORT_SCIFA) {
u16 new, scr = sci_in(port, SCSCR);
if (s->chan_tx)
new = scr | 0x8000;
else
new = scr & ~0x8000;
if (new != scr)
sci_out(port, SCSCR, new);
}
if (s->chan_tx && !uart_circ_empty(&s->port.state->xmit) &&
s->cookie_tx < 0)
schedule_work(&s->work_tx);
#endif

/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
ctrl = sci_in(port, SCSCR);
ctrl |= SCI_CTRL_FLAGS_TIE;
sci_out(port, SCSCR, ctrl);
if (!s->chan_tx || port->type == PORT_SCIFA) {
/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */
ctrl = sci_in(port, SCSCR);
sci_out(port, SCSCR, ctrl | SCI_CTRL_FLAGS_TIE);
}
}

static void sci_stop_tx(struct uart_port *port)
Expand All @@ -1200,6 +1212,8 @@ static void sci_stop_tx(struct uart_port *port)

/* Clear TIE (Transmit Interrupt Enable) bit in SCSCR */
ctrl = sci_in(port, SCSCR);
if (port->type == PORT_SCIFA)
ctrl &= ~0x8000;
ctrl &= ~SCI_CTRL_FLAGS_TIE;
sci_out(port, SCSCR, ctrl);
}
Expand All @@ -1210,6 +1224,8 @@ static void sci_start_rx(struct uart_port *port)

/* Set RIE (Receive Interrupt Enable) bit in SCSCR */
ctrl |= sci_in(port, SCSCR);
if (port->type == PORT_SCIFA)
ctrl &= ~0x4000;
sci_out(port, SCSCR, ctrl);
}

Expand All @@ -1219,6 +1235,8 @@ static void sci_stop_rx(struct uart_port *port)

/* Clear RIE (Receive Interrupt Enable) bit in SCSCR */
ctrl = sci_in(port, SCSCR);
if (port->type == PORT_SCIFA)
ctrl &= ~0x4000;
ctrl &= ~(SCI_CTRL_FLAGS_RIE | SCI_CTRL_FLAGS_REIE);
sci_out(port, SCSCR, ctrl);
}
Expand Down Expand Up @@ -1253,8 +1271,12 @@ static void rx_timer_fn(unsigned long arg)
{
struct sci_port *s = (struct sci_port *)arg;
struct uart_port *port = &s->port;

u16 scr = sci_in(port, SCSCR);

if (port->type == PORT_SCIFA) {
scr &= ~0x4000;
enable_irq(s->irqs[1]);
}
sci_out(port, SCSCR, scr | SCI_CTRL_FLAGS_RIE);
dev_dbg(port->dev, "DMA Rx timed out\n");
schedule_work(&s->work_rx);
Expand Down Expand Up @@ -1404,8 +1426,12 @@ static void sci_shutdown(struct uart_port *port)
static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
struct ktermios *old)
{
#ifdef CONFIG_SERIAL_SH_SCI_DMA
struct sci_port *s = to_sci_port(port);
#endif
unsigned int status, baud, smr_val, max_baud;
int t = -1;
u16 scfcr = 0;

/*
* earlyprintk comes here early on with port->uartclk set to zero.
Expand All @@ -1428,7 +1454,7 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
sci_out(port, SCSCR, 0x00); /* TE=0, RE=0, CKE1=0 */

if (port->type != PORT_SCI)
sci_out(port, SCFCR, SCFCR_RFRST | SCFCR_TFRST);
sci_out(port, SCFCR, scfcr | SCFCR_RFRST | SCFCR_TFRST);

smr_val = sci_in(port, SCSMR) & 3;
if ((termios->c_cflag & CSIZE) == CS7)
Expand Down Expand Up @@ -1459,10 +1485,32 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios,
}

sci_init_pins(port, termios->c_cflag);
sci_out(port, SCFCR, (termios->c_cflag & CRTSCTS) ? SCFCR_MCE : 0);
sci_out(port, SCFCR, scfcr | ((termios->c_cflag & CRTSCTS) ? SCFCR_MCE : 0));

sci_out(port, SCSCR, SCSCR_INIT(port));

#ifdef CONFIG_SERIAL_SH_SCI_DMA
/*
* Calculate delay for 1.5 DMA buffers: see
* drivers/serial/serial_core.c::uart_update_timeout(). With 10 bits
* (CS8), 250Hz, 115200 baud and 64 bytes FIFO, the above function
* calculates 1 jiffie for the data plus 5 jiffies for the "slop(e)."
* Then below we calculate 3 jiffies (12ms) for 1.5 DMA buffers (3 FIFO
* sizes), but it has been found out experimentally, that this is not
* enough: the driver too often needlessly runs on a DMA timeout. 20ms
* as a minimum seem to work perfectly.
*/
if (s->chan_rx) {
s->rx_timeout = (port->timeout - HZ / 50) * s->buf_len_rx * 3 /
port->fifosize / 2;
dev_dbg(port->dev,
"DMA Rx t-out %ums, tty t-out %u jiffies\n",
s->rx_timeout * 1000 / HZ, port->timeout);
if (s->rx_timeout < msecs_to_jiffies(20))
s->rx_timeout = msecs_to_jiffies(20);
}
#endif

if ((termios->c_cflag & CREAD) != 0)
sci_start_rx(port);
}
Expand Down

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