summaryrefslogtreecommitdiffstats
path: root/drivers/serial/sh-sci.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/serial/sh-sci.c')
-rw-r--r--drivers/serial/sh-sci.c195
1 files changed, 131 insertions, 64 deletions
diff --git a/drivers/serial/sh-sci.c b/drivers/serial/sh-sci.c
index 8eb094c1f61..f250a610a26 100644
--- a/drivers/serial/sh-sci.c
+++ b/drivers/serial/sh-sci.c
@@ -83,16 +83,16 @@ struct sci_port {
/* Interface clock */
struct clk *iclk;
- /* Data clock */
- struct clk *dclk;
+ /* Function clock */
+ struct clk *fclk;
struct list_head node;
struct dma_chan *chan_tx;
struct dma_chan *chan_rx;
#ifdef CONFIG_SERIAL_SH_SCI_DMA
struct device *dma_dev;
- enum sh_dmae_slave_chan_id slave_tx;
- enum sh_dmae_slave_chan_id slave_rx;
+ unsigned int slave_tx;
+ unsigned int slave_rx;
struct dma_async_tx_descriptor *desc_tx;
struct dma_async_tx_descriptor *desc_rx[2];
dma_cookie_t cookie_tx;
@@ -107,6 +107,7 @@ struct sci_port {
struct work_struct work_tx;
struct work_struct work_rx;
struct timer_list rx_timer;
+ unsigned int rx_timeout;
#endif
};
@@ -150,7 +151,11 @@ static int sci_poll_get_char(struct uart_port *port)
handle_error(port);
continue;
}
- } while (!(status & SCxSR_RDxF(port)));
+ break;
+ } while (1);
+
+ if (!(status & SCxSR_RDxF(port)))
+ return NO_POLL_CHAR;
c = sci_in(port, SCxRDR);
@@ -674,22 +679,22 @@ 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;
}
@@ -799,7 +804,7 @@ static int sci_notifier(struct notifier_block *self,
(phase == CPUFREQ_RESUMECHANGE)) {
spin_lock_irqsave(&priv->lock, flags);
list_for_each_entry(sci_port, &priv->ports, node)
- sci_port->port.uartclk = clk_get_rate(sci_port->dclk);
+ sci_port->port.uartclk = clk_get_rate(sci_port->iclk);
spin_unlock_irqrestore(&priv->lock, flags);
}
@@ -810,21 +815,17 @@ static void sci_clk_enable(struct uart_port *port)
{
struct sci_port *sci_port = to_sci_port(port);
- clk_enable(sci_port->dclk);
- sci_port->port.uartclk = clk_get_rate(sci_port->dclk);
-
- if (sci_port->iclk)
- clk_enable(sci_port->iclk);
+ clk_enable(sci_port->iclk);
+ sci_port->port.uartclk = clk_get_rate(sci_port->iclk);
+ clk_enable(sci_port->fclk);
}
static void sci_clk_disable(struct uart_port *port)
{
struct sci_port *sci_port = to_sci_port(port);
- if (sci_port->iclk)
- clk_disable(sci_port->iclk);
-
- clk_disable(sci_port->dclk);
+ clk_disable(sci_port->fclk);
+ clk_disable(sci_port->iclk);
}
static int sci_request_irq(struct sci_port *port)
@@ -913,22 +914,26 @@ static void sci_dma_tx_complete(void *arg)
spin_lock_irqsave(&port->lock, flags);
- xmit->tail += s->sg_tx.length;
+ xmit->tail += sg_dma_len(&s->sg_tx);
xmit->tail &= UART_XMIT_SIZE - 1;
- port->icount.tx += s->sg_tx.length;
+ port->icount.tx += sg_dma_len(&s->sg_tx);
async_tx_ack(s->desc_tx);
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 */
@@ -972,13 +977,13 @@ 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);
@@ -1050,6 +1055,8 @@ 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];
@@ -1107,10 +1114,10 @@ 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)
@@ -1131,14 +1138,13 @@ static void work_fn_tx(struct work_struct *work)
*/
spin_lock_irq(&port->lock);
sg->offset = xmit->tail & (UART_XMIT_SIZE - 1);
- sg->dma_address = (sg_dma_address(sg) & ~(UART_XMIT_SIZE - 1)) +
+ sg_dma_address(sg) = (sg_dma_address(sg) & ~(UART_XMIT_SIZE - 1)) +
sg->offset;
- sg->length = min((int)CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
+ sg_dma_len(sg) = min((int)CIRC_CNT(xmit->head, xmit->tail, UART_XMIT_SIZE),
CIRC_CNT_TO_END(xmit->head, xmit->tail, UART_XMIT_SIZE));
- sg->dma_length = sg->length;
spin_unlock_irq(&port->lock);
- BUG_ON(!sg->length);
+ BUG_ON(!sg_dma_len(sg));
desc = chan->device->device_prep_slave_sg(chan,
sg, s->sg_len_tx, DMA_TO_DEVICE,
@@ -1173,23 +1179,28 @@ 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)
@@ -1198,6 +1209,8 @@ 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);
}
@@ -1208,6 +1221,8 @@ 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);
}
@@ -1217,6 +1232,8 @@ 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);
}
@@ -1251,8 +1268,12 @@ 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);
@@ -1339,8 +1360,7 @@ static void sci_request_dma(struct uart_port *port)
sg_init_table(sg, 1);
sg_set_page(sg, virt_to_page(buf[i]), s->buf_len_rx,
(int)buf[i] & ~PAGE_MASK);
- sg->dma_address = dma[i];
- sg->dma_length = sg->length;
+ sg_dma_address(sg) = dma[i];
}
INIT_WORK(&s->work_rx, work_fn_rx);
@@ -1403,8 +1423,12 @@ 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.
@@ -1427,7 +1451,7 @@ 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)
@@ -1458,10 +1482,32 @@ 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);
}
@@ -1553,10 +1599,10 @@ static struct uart_ops sci_uart_ops = {
#endif
};
-static void __devinit sci_init_single(struct platform_device *dev,
- struct sci_port *sci_port,
- unsigned int index,
- struct plat_sci_port *p)
+static int __devinit sci_init_single(struct platform_device *dev,
+ struct sci_port *sci_port,
+ unsigned int index,
+ struct plat_sci_port *p)
{
struct uart_port *port = &sci_port->port;
@@ -1577,8 +1623,23 @@ static void __devinit sci_init_single(struct platform_device *dev,
}
if (dev) {
- sci_port->iclk = p->clk ? clk_get(&dev->dev, p->clk) : NULL;
- sci_port->dclk = clk_get(&dev->dev, "peripheral_clk");
+ sci_port->iclk = clk_get(&dev->dev, "sci_ick");
+ if (IS_ERR(sci_port->iclk)) {
+ sci_port->iclk = clk_get(&dev->dev, "peripheral_clk");
+ if (IS_ERR(sci_port->iclk)) {
+ dev_err(&dev->dev, "can't get iclk\n");
+ return PTR_ERR(sci_port->iclk);
+ }
+ }
+
+ /*
+ * The function clock is optional, ignore it if we can't
+ * find it.
+ */
+ sci_port->fclk = clk_get(&dev->dev, "sci_fck");
+ if (IS_ERR(sci_port->fclk))
+ sci_port->fclk = NULL;
+
sci_port->enable = sci_clk_enable;
sci_port->disable = sci_clk_disable;
port->dev = &dev->dev;
@@ -1605,6 +1666,7 @@ static void __devinit sci_init_single(struct platform_device *dev,
#endif
memcpy(&sci_port->irqs, &p->irqs, sizeof(p->irqs));
+ return 0;
}
#ifdef CONFIG_SERIAL_SH_SCI_CONSOLE
@@ -1754,8 +1816,11 @@ static int sci_remove(struct platform_device *dev)
cpufreq_unregister_notifier(&priv->clk_nb, CPUFREQ_TRANSITION_NOTIFIER);
spin_lock_irqsave(&priv->lock, flags);
- list_for_each_entry(p, &priv->ports, node)
+ list_for_each_entry(p, &priv->ports, node) {
uart_remove_one_port(&sci_uart_driver, &p->port);
+ clk_put(p->iclk);
+ clk_put(p->fclk);
+ }
spin_unlock_irqrestore(&priv->lock, flags);
kfree(priv);
@@ -1781,7 +1846,9 @@ static int __devinit sci_probe_single(struct platform_device *dev,
return 0;
}
- sci_init_single(dev, sciport, index, p);
+ ret = sci_init_single(dev, sciport, index, p);
+ if (ret)
+ return ret;
ret = uart_add_one_port(&sci_uart_driver, &sciport->port);
if (ret)