Commit 73a19e4c authored by Guennadi Liakhovetski's avatar Guennadi Liakhovetski Committed by Paul Mundt
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serial: sh-sci: Add DMA support. 



Support using DMA for sending and receiving data over SCI(F) interfaces of
various SH SoCs.

Signed-off-by: default avatarGuennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent c014906a

drivers/serial/Kconfig

+4 −0
Original line number Diff line number Diff line
@@ -1009,6 +1009,10 @@ config SERIAL_SH_SCI_CONSOLE 
	depends on SERIAL_SH_SCI=y

	select SERIAL_CORE_CONSOLE



config SERIAL_SH_SCI_DMA

	bool "DMA support"

	depends on SERIAL_SH_SCI && SH_DMAE && EXPERIMENTAL



config SERIAL_PNX8XXX

	bool "Enable PNX8XXX SoCs' UART Support"

	depends on MIPS && (SOC_PNX8550 || SOC_PNX833X)

drivers/serial/sh-sci.c

+572 −46
Original line number Diff line number Diff line
@@ -48,6 +48,9 @@ 
#include <linux/ctype.h>

#include <linux/err.h>

#include <linux/list.h>

#include <linux/dmaengine.h>

#include <linux/scatterlist.h>

#include <linux/timer.h>



#ifdef CONFIG_SUPERH

#include <asm/sh_bios.h>
@@ -84,6 +87,27 @@ struct sci_port { 
	struct clk		*dclk;



	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;

	struct dma_async_tx_descriptor	*desc_tx;

	struct dma_async_tx_descriptor	*desc_rx[2];

	dma_cookie_t			cookie_tx;

	dma_cookie_t			cookie_rx[2];

	dma_cookie_t			active_rx;

	struct scatterlist		sg_tx;

	unsigned int			sg_len_tx;

	struct scatterlist		sg_rx[2];

	size_t				buf_len_rx;

	struct sh_dmae_slave		param_tx;

	struct sh_dmae_slave		param_rx;

	struct work_struct		work_tx;

	struct work_struct		work_rx;

	struct timer_list		rx_timer;

#endif

};



struct sh_sci_priv {
@@ -269,29 +293,44 @@ static inline void sci_init_pins(struct uart_port *port, unsigned int cflag) 
    defined(CONFIG_CPU_SUBTYPE_SH7780) || \

    defined(CONFIG_CPU_SUBTYPE_SH7785) || \

    defined(CONFIG_CPU_SUBTYPE_SH7786)

static inline int scif_txroom(struct uart_port *port)

static int scif_txfill(struct uart_port *port)

{

	return SCIF_TXROOM_MAX - (sci_in(port, SCTFDR) & 0xff);

	return sci_in(port, SCTFDR) & 0xff;

}



static inline int scif_rxroom(struct uart_port *port)

static int scif_txroom(struct uart_port *port)

{

	return SCIF_TXROOM_MAX - scif_txfill(port);

}



static int scif_rxfill(struct uart_port *port)

{

	return sci_in(port, SCRFDR) & 0xff;

}

#elif defined(CONFIG_CPU_SUBTYPE_SH7763)

static inline int scif_txroom(struct uart_port *port)

static int scif_txfill(struct uart_port *port)

{

	if ((port->mapbase == 0xffe00000) ||

	    (port->mapbase == 0xffe08000)) {

	if (port->mapbase == 0xffe00000 ||

	    port->mapbase == 0xffe08000)

		/* SCIF0/1*/

		return SCIF_TXROOM_MAX - (sci_in(port, SCTFDR) & 0xff);

	} else {

		return sci_in(port, SCTFDR) & 0xff;

	else

		/* SCIF2 */

		return SCIF2_TXROOM_MAX - (sci_in(port, SCFDR) >> 8);

		return sci_in(port, SCFDR) >> 8;

}



static int scif_txroom(struct uart_port *port)

{

	if (port->mapbase == 0xffe00000 ||

	    port->mapbase == 0xffe08000)

		/* SCIF0/1*/

		return SCIF_TXROOM_MAX - scif_txfill(port);

	else

		/* SCIF2 */

		return SCIF2_TXROOM_MAX - scif_txfill(port);

}



static inline int scif_rxroom(struct uart_port *port)

static int scif_rxfill(struct uart_port *port)

{

	if ((port->mapbase == 0xffe00000) ||

	    (port->mapbase == 0xffe08000)) {
@@ -303,23 +342,33 @@ static inline int scif_rxroom(struct uart_port *port) 
	}

}

#else

static inline int scif_txroom(struct uart_port *port)

static int scif_txfill(struct uart_port *port)

{

	return SCIF_TXROOM_MAX - (sci_in(port, SCFDR) >> 8);

	return sci_in(port, SCFDR) >> 8;

}



static inline int scif_rxroom(struct uart_port *port)

static int scif_txroom(struct uart_port *port)

{

	return SCIF_TXROOM_MAX - scif_txfill(port);

}



static int scif_rxfill(struct uart_port *port)

{

	return sci_in(port, SCFDR) & SCIF_RFDC_MASK;

}

#endif



static inline int sci_txroom(struct uart_port *port)

static int sci_txfill(struct uart_port *port)

{

	return (sci_in(port, SCxSR) & SCI_TDRE) != 0;

	return !(sci_in(port, SCxSR) & SCI_TDRE);

}



static inline int sci_rxroom(struct uart_port *port)

static int sci_txroom(struct uart_port *port)

{

	return !sci_txfill(port);

}



static int sci_rxfill(struct uart_port *port)

{

	return (sci_in(port, SCxSR) & SCxSR_RDxF(port)) != 0;

}
@@ -406,9 +455,9 @@ static inline void sci_receive_chars(struct uart_port *port) 


	while (1) {

		if (port->type == PORT_SCI)

			count = sci_rxroom(port);

			count = sci_rxfill(port);

		else

			count = scif_rxroom(port);

			count = scif_rxfill(port);



		/* Don't copy more bytes than there is room for in the buffer */

		count = tty_buffer_request_room(tty, count);
@@ -618,13 +667,39 @@ static inline int sci_handle_breaks(struct uart_port *port) 
	return copied;

}



static irqreturn_t sci_rx_interrupt(int irq, void *port)

static irqreturn_t sci_rx_interrupt(int irq, void *ptr)

{

#ifdef CONFIG_SERIAL_SH_SCI_DMA

	struct uart_port *port = 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);

		/* 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 %u ms\n",

			tout * 1000 / HZ);

		if (tout < 2)

			tout = 2;

		mod_timer(&s->rx_timer, jiffies + tout);



		return IRQ_HANDLED;

	}

#endif



	/* I think sci_receive_chars has to be called irrespective

	 * of whether the I_IXOFF is set, otherwise, how is the interrupt

	 * to be disabled?

	 */

	sci_receive_chars(port);

	sci_receive_chars(ptr);



	return IRQ_HANDLED;

}
@@ -680,6 +755,7 @@ static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr) 
{

	unsigned short ssr_status, scr_status, err_enabled;

	struct uart_port *port = ptr;

	struct sci_port *s = to_sci_port(port);

	irqreturn_t ret = IRQ_NONE;



	ssr_status = sci_in(port, SCxSR);
@@ -687,10 +763,15 @@ static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr) 
	err_enabled = scr_status & (SCI_CTRL_FLAGS_REIE | SCI_CTRL_FLAGS_RIE);



	/* Tx Interrupt */

	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCI_CTRL_FLAGS_TIE))

	if ((ssr_status & SCxSR_TDxE(port)) && (scr_status & SCI_CTRL_FLAGS_TIE) &&

	    !s->chan_tx)

		ret = sci_tx_interrupt(irq, ptr);

	/* Rx Interrupt */

	if ((ssr_status & SCxSR_RDxF(port)) && (scr_status & SCI_CTRL_FLAGS_RIE))

	/*

	 * Rx Interrupt: if we're using DMA, the DMA controller clears RDF /

	 * DR flags

	 */

	if (((ssr_status & SCxSR_RDxF(port)) || s->chan_rx) &&

	    (scr_status & SCI_CTRL_FLAGS_RIE))

		ret = sci_rx_interrupt(irq, ptr);

	/* Error Interrupt */

	if ((ssr_status & SCxSR_ERRORS(port)) && err_enabled)
@@ -699,6 +780,10 @@ static irqreturn_t sci_mpxed_interrupt(int irq, void *ptr) 
	if ((ssr_status & SCxSR_BRK(port)) && err_enabled)

		ret = sci_br_interrupt(irq, ptr);



	WARN_ONCE(ret == IRQ_NONE,

		  "%s: %d IRQ %d, status %x, control %x\n", __func__,

		  irq, port->line, ssr_status, scr_status);



	return ret;

}
@@ -800,7 +885,9 @@ static void sci_free_irq(struct sci_port *port) 
static unsigned int sci_tx_empty(struct uart_port *port)

{

	unsigned short status = sci_in(port, SCxSR);

	return status & SCxSR_TEND(port) ? TIOCSER_TEMT : 0;

	unsigned short in_tx_fifo = scif_txfill(port);



	return (status & SCxSR_TEND(port)) && !in_tx_fifo ? TIOCSER_TEMT : 0;

}



static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl)
@@ -812,16 +899,299 @@ static void sci_set_mctrl(struct uart_port *port, unsigned int mctrl) 


static unsigned int sci_get_mctrl(struct uart_port *port)

{

	/* This routine is used for geting signals of: DTR, DCD, DSR, RI,

	/* This routine is used for getting signals of: DTR, DCD, DSR, RI,

	   and CTS/RTS */



	return TIOCM_DTR | TIOCM_RTS | TIOCM_DSR;

}



#ifdef CONFIG_SERIAL_SH_SCI_DMA

static void sci_dma_tx_complete(void *arg)

{

	struct sci_port *s = arg;

	struct uart_port *port = &s->port;

	struct circ_buf *xmit = &port->state->xmit;

	unsigned long flags;



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



	spin_lock_irqsave(&port->lock, flags);



	xmit->tail += s->sg_tx.length;

	xmit->tail &= UART_XMIT_SIZE - 1;



	port->icount.tx += s->sg_tx.length;



	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))

		schedule_work(&s->work_tx);

}



/* Locking: called with port lock held */

static int sci_dma_rx_push(struct sci_port *s, struct tty_struct *tty,

			   size_t count)

{

	struct uart_port *port = &s->port;

	int i, active, room;



	room = tty_buffer_request_room(tty, count);



	if (s->active_rx == s->cookie_rx[0]) {

		active = 0;

	} else if (s->active_rx == s->cookie_rx[1]) {

		active = 1;

	} else {

		dev_err(port->dev, "cookie %d not found!\n", s->active_rx);

		return 0;

	}



	if (room < count)

		dev_warn(port->dev, "Rx overrun: dropping %u bytes\n",

			 count - room);

	if (!room)

		return room;



	for (i = 0; i < room; i++)

		tty_insert_flip_char(tty, ((u8 *)sg_virt(&s->sg_rx[active]))[i],

				     TTY_NORMAL);



	port->icount.rx += room;



	return room;

}



static void sci_dma_rx_complete(void *arg)

{

	struct sci_port *s = arg;

	struct uart_port *port = &s->port;

	struct tty_struct *tty = port->state->port.tty;

	unsigned long flags;

	int count;



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



	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));



	spin_unlock_irqrestore(&port->lock, flags);



	if (count)

		tty_flip_buffer_push(tty);



	schedule_work(&s->work_rx);

}



static void sci_start_rx(struct uart_port *port);

static void sci_start_tx(struct uart_port *port);



static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)

{

	struct dma_chan *chan = s->chan_rx;

	struct uart_port *port = &s->port;

	unsigned long flags;



	s->chan_rx = NULL;

	s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;

	dma_release_channel(chan);

	dma_free_coherent(port->dev, s->buf_len_rx * 2,

			  sg_virt(&s->sg_rx[0]), sg_dma_address(&s->sg_rx[0]));

	if (enable_pio)

		sci_start_rx(port);

}



static void sci_tx_dma_release(struct sci_port *s, bool enable_pio)

{

	struct dma_chan *chan = s->chan_tx;

	struct uart_port *port = &s->port;

	unsigned long flags;



	s->chan_tx = NULL;

	s->cookie_tx = -EINVAL;

	dma_release_channel(chan);

	if (enable_pio)

		sci_start_tx(port);

}



static void sci_submit_rx(struct sci_port *s)

{

	struct dma_chan *chan = s->chan_rx;

	int i;



	for (i = 0; i < 2; i++) {

		struct scatterlist *sg = &s->sg_rx[i];

		struct dma_async_tx_descriptor *desc;



		desc = chan->device->device_prep_slave_sg(chan,

			sg, 1, DMA_FROM_DEVICE, DMA_PREP_INTERRUPT);



		if (desc) {

			s->desc_rx[i] = desc;

			desc->callback = sci_dma_rx_complete;

			desc->callback_param = s;

			s->cookie_rx[i] = desc->tx_submit(desc);

		}



		if (!desc || s->cookie_rx[i] < 0) {

			if (i) {

				async_tx_ack(s->desc_rx[0]);

				s->cookie_rx[0] = -EINVAL;

			}

			if (desc) {

				async_tx_ack(desc);

				s->cookie_rx[i] = -EINVAL;

			}

			dev_warn(s->port.dev,

				 "failed to re-start DMA, using PIO\n");

			sci_rx_dma_release(s, true);

			return;

		}

	}



	s->active_rx = s->cookie_rx[0];



	dma_async_issue_pending(chan);

}



static void work_fn_rx(struct work_struct *work)

{

	struct sci_port *s = container_of(work, struct sci_port, work_rx);

	struct uart_port *port = &s->port;

	struct dma_async_tx_descriptor *desc;

	int new;



	if (s->active_rx == s->cookie_rx[0]) {

		new = 0;

	} else if (s->active_rx == s->cookie_rx[1]) {

		new = 1;

	} else {

		dev_err(port->dev, "cookie %d not found!\n", s->active_rx);

		return;

	}

	desc = s->desc_rx[new];



	if (dma_async_is_tx_complete(s->chan_rx, s->active_rx, NULL, NULL) !=

	    DMA_SUCCESS) {

		/* Handle incomplete DMA receive */

		struct tty_struct *tty = port->state->port.tty;

		struct dma_chan *chan = s->chan_rx;

		struct sh_desc *sh_desc = container_of(desc, struct sh_desc,

						       async_tx);

		unsigned long flags;

		int count;



		chan->device->device_terminate_all(chan);

		dev_dbg(port->dev, "Read %u bytes with cookie %d\n",

			sh_desc->partial, sh_desc->cookie);



		spin_lock_irqsave(&port->lock, flags);

		count = sci_dma_rx_push(s, tty, sh_desc->partial);

		spin_unlock_irqrestore(&port->lock, flags);



		if (count)

			tty_flip_buffer_push(tty);



		sci_submit_rx(s);



		return;

	}



	s->cookie_rx[new] = desc->tx_submit(desc);

	if (s->cookie_rx[new] < 0) {

		dev_warn(port->dev, "Failed submitting Rx DMA descriptor\n");

		sci_rx_dma_release(s, true);

		return;

	}



	dev_dbg(port->dev, "%s: cookie %d #%d\n", __func__,

		s->cookie_rx[new], new);



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

}



static void work_fn_tx(struct work_struct *work)

{

	struct sci_port *s = container_of(work, struct sci_port, work_tx);

	struct dma_async_tx_descriptor *desc;

	struct dma_chan *chan = s->chan_tx;

	struct uart_port *port = &s->port;

	struct circ_buf *xmit = &port->state->xmit;

	struct scatterlist *sg = &s->sg_tx;



	/*

	 * DMA is idle now.

	 * Port xmit buffer is already mapped, and it is one page... Just adjust

	 * offsets and lengths. Since it is a circular buffer, we have to

	 * transmit till the end, and then the rest. Take the port lock to get a

	 * consistent xmit buffer state.

	 */

	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->offset;

	sg->length = 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);



	desc = chan->device->device_prep_slave_sg(chan,

			sg, s->sg_len_tx, DMA_TO_DEVICE,

			DMA_PREP_INTERRUPT | DMA_CTRL_ACK);

	if (!desc) {

		/* switch to PIO */

		sci_tx_dma_release(s, true);

		return;

	}



	dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE);



	spin_lock_irq(&port->lock);

	s->desc_tx = desc;

	desc->callback = sci_dma_tx_complete;

	desc->callback_param = s;

	spin_unlock_irq(&port->lock);

	s->cookie_tx = desc->tx_submit(desc);

	if (s->cookie_tx < 0) {

		dev_warn(port->dev, "Failed submitting Tx DMA descriptor\n");

		/* switch to PIO */

		sci_tx_dma_release(s, true);

		return;

	}



	dev_dbg(port->dev, "%s: %p: %d...%d, cookie %d\n", __func__,

		xmit->buf, xmit->tail, xmit->head, s->cookie_tx);



	dma_async_issue_pending(chan);

}

#endif



static void sci_start_tx(struct uart_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;

	}

#endif



	/* Set TIE (Transmit Interrupt Enable) bit in SCSCR */

	ctrl = sci_in(port, SCSCR);

	ctrl |= SCI_CTRL_FLAGS_TIE;
@@ -838,13 +1208,12 @@ static void sci_stop_tx(struct uart_port *port) 
	sci_out(port, SCSCR, ctrl);

}



static void sci_start_rx(struct uart_port *port, unsigned int tty_start)

static void sci_start_rx(struct uart_port *port)

{

	unsigned short ctrl;

	unsigned short ctrl = SCI_CTRL_FLAGS_RIE | SCI_CTRL_FLAGS_REIE;



	/* Set RIE (Receive Interrupt Enable) bit in SCSCR */

	ctrl = sci_in(port, SCSCR);

	ctrl |= SCI_CTRL_FLAGS_RIE | SCI_CTRL_FLAGS_REIE;

	ctrl |= sci_in(port, SCSCR);

	sci_out(port, SCSCR, ctrl);

}
@@ -868,16 +1237,154 @@ static void sci_break_ctl(struct uart_port *port, int break_state) 
	/* Nothing here yet .. */

}



#ifdef CONFIG_SERIAL_SH_SCI_DMA

static bool filter(struct dma_chan *chan, void *slave)

{

	struct sh_dmae_slave *param = slave;



	dev_dbg(chan->device->dev, "%s: slave ID %d\n", __func__,

		param->slave_id);



	if (param->dma_dev == chan->device->dev) {

		chan->private = param;

		return true;

	} else {

		return false;

	}

}



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);

	sci_out(port, SCSCR, scr | SCI_CTRL_FLAGS_RIE);

	dev_dbg(port->dev, "DMA Rx timed out\n");

	schedule_work(&s->work_rx);

}



static void sci_request_dma(struct uart_port *port)

{

	struct sci_port *s = to_sci_port(port);

	struct sh_dmae_slave *param;

	struct dma_chan *chan;

	dma_cap_mask_t mask;

	int nent;



	dev_dbg(port->dev, "%s: port %d DMA %p\n", __func__,

		port->line, s->dma_dev);



	if (!s->dma_dev)

		return;



	dma_cap_zero(mask);

	dma_cap_set(DMA_SLAVE, mask);



	param = &s->param_tx;



	/* Slave ID, e.g., SHDMA_SLAVE_SCIF0_TX */

	param->slave_id = s->slave_tx;

	param->dma_dev = s->dma_dev;



	s->cookie_tx = -EINVAL;

	chan = dma_request_channel(mask, filter, param);

	dev_dbg(port->dev, "%s: TX: got channel %p\n", __func__, chan);

	if (chan) {

		s->chan_tx = chan;

		sg_init_table(&s->sg_tx, 1);

		/* UART circular tx buffer is an aligned page. */

		BUG_ON((int)port->state->xmit.buf & ~PAGE_MASK);

		sg_set_page(&s->sg_tx, virt_to_page(port->state->xmit.buf),

			    UART_XMIT_SIZE, (int)port->state->xmit.buf & ~PAGE_MASK);

		nent = dma_map_sg(port->dev, &s->sg_tx, 1, DMA_TO_DEVICE);

		if (!nent)

			sci_tx_dma_release(s, false);

		else

			dev_dbg(port->dev, "%s: mapped %d@%p to %x\n", __func__,

				sg_dma_len(&s->sg_tx),

				port->state->xmit.buf, sg_dma_address(&s->sg_tx));



		s->sg_len_tx = nent;



		INIT_WORK(&s->work_tx, work_fn_tx);

	}



	param = &s->param_rx;



	/* Slave ID, e.g., SHDMA_SLAVE_SCIF0_RX */

	param->slave_id = s->slave_rx;

	param->dma_dev = s->dma_dev;



	chan = dma_request_channel(mask, filter, param);

	dev_dbg(port->dev, "%s: RX: got channel %p\n", __func__, chan);

	if (chan) {

		dma_addr_t dma[2];

		void *buf[2];

		int i;



		s->chan_rx = chan;



		s->buf_len_rx = 2 * max(16, (int)port->fifosize);

		buf[0] = dma_alloc_coherent(port->dev, s->buf_len_rx * 2,

					    &dma[0], GFP_KERNEL);



		if (!buf[0]) {

			dev_warn(port->dev,

				 "failed to allocate dma buffer, using PIO\n");

			sci_rx_dma_release(s, true);

			return;

		}



		buf[1] = buf[0] + s->buf_len_rx;

		dma[1] = dma[0] + s->buf_len_rx;



		for (i = 0; i < 2; i++) {

			struct scatterlist *sg = &s->sg_rx[i];



			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;

		}



		INIT_WORK(&s->work_rx, work_fn_rx);

		setup_timer(&s->rx_timer, rx_timer_fn, (unsigned long)s);



		sci_submit_rx(s);

	}

}



static void sci_free_dma(struct uart_port *port)

{

	struct sci_port *s = to_sci_port(port);



	if (!s->dma_dev)

		return;



	if (s->chan_tx)

		sci_tx_dma_release(s, false);

	if (s->chan_rx)

		sci_rx_dma_release(s, false);

}

#endif



static int sci_startup(struct uart_port *port)

{

	struct sci_port *s = to_sci_port(port);



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



	if (s->enable)

		s->enable(port);



	sci_request_irq(s);

#ifdef CONFIG_SERIAL_SH_SCI_DMA

	sci_request_dma(port);

#endif

	sci_start_tx(port);

	sci_start_rx(port, 1);

	sci_start_rx(port);



	return 0;

}
@@ -886,8 +1393,13 @@ static void sci_shutdown(struct uart_port *port) 
{

	struct sci_port *s = to_sci_port(port);



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



	sci_stop_rx(port);

	sci_stop_tx(port);

#ifdef CONFIG_SERIAL_SH_SCI_DMA

	sci_free_dma(port);

#endif

	sci_free_irq(s);



	if (s->disable)
@@ -937,6 +1449,9 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, 


	sci_out(port, SCSMR, smr_val);



	dev_dbg(port->dev, "%s: SMR %x, t %x, SCSCR %x\n", __func__, smr_val, t,

		SCSCR_INIT(port));



	if (t > 0) {

		if (t >= 256) {

			sci_out(port, SCSMR, (sci_in(port, SCSMR) & ~3) | 1);
@@ -954,7 +1469,7 @@ static void sci_set_termios(struct uart_port *port, struct ktermios *termios, 
	sci_out(port, SCSCR, SCSCR_INIT(port));



	if ((termios->c_cflag & CREAD) != 0)

		sci_start_rx(port, 0);

		sci_start_rx(port);

}



static const char *sci_type(struct uart_port *port)
@@ -1049,19 +1564,21 @@ static void __devinit sci_init_single(struct platform_device *dev, 
				      unsigned int index,

				      struct plat_sci_port *p)

{

	sci_port->port.ops	= &sci_uart_ops;

	sci_port->port.iotype	= UPIO_MEM;

	sci_port->port.line	= index;

	struct uart_port *port = &sci_port->port;



	port->ops	= &sci_uart_ops;

	port->iotype	= UPIO_MEM;

	port->line	= index;



	switch (p->type) {

	case PORT_SCIFA:

		sci_port->port.fifosize = 64;

		port->fifosize = 64;

		break;

	case PORT_SCIF:

		sci_port->port.fifosize = 16;

		port->fifosize = 16;

		break;

	default:

		sci_port->port.fifosize = 1;

		port->fifosize = 1;

		break;

	}
@@ -1070,19 +1587,28 @@ static void __devinit sci_init_single(struct platform_device *dev, 
		sci_port->dclk = clk_get(&dev->dev, "peripheral_clk");

		sci_port->enable = sci_clk_enable;

		sci_port->disable = sci_clk_disable;

		sci_port->port.dev = &dev->dev;

		port->dev = &dev->dev;

	}



	sci_port->break_timer.data = (unsigned long)sci_port;

	sci_port->break_timer.function = sci_break_timer;

	init_timer(&sci_port->break_timer);



	sci_port->port.mapbase	= p->mapbase;

	sci_port->port.membase	= p->membase;

	port->mapbase	= p->mapbase;

	port->membase	= p->membase;



	sci_port->port.irq	= p->irqs[SCIx_TXI_IRQ];

	sci_port->port.flags	= p->flags;

	sci_port->type		= sci_port->port.type = p->type;

	port->irq	= p->irqs[SCIx_TXI_IRQ];

	port->flags	= p->flags;

	sci_port->type	= port->type = p->type;



#ifdef CONFIG_SERIAL_SH_SCI_DMA

	sci_port->dma_dev	= p->dma_dev;

	sci_port->slave_tx	= p->dma_slave_tx;

	sci_port->slave_rx	= p->dma_slave_rx;



	dev_dbg(port->dev, "%s: DMA device %p, tx %d, rx %d\n", __func__,

		p->dma_dev, p->dma_slave_tx, p->dma_slave_rx);

#endif



	memcpy(&sci_port->irqs, &p->irqs, sizeof(p->irqs));

}

include/linux/serial_sci.h

+6 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#define __LINUX_SERIAL_SCI_H



#include <linux/serial_core.h>

#include <asm/dmaengine.h>



/*

 * Generic header for SuperH SCI(F) (used by sh/sh64/h8300 and related parts)
@@ -16,6 +17,8 @@ enum { 
	SCIx_NR_IRQS,

};



struct device;



/*

 * Platform device specific platform_data struct

 */
@@ -26,6 +29,9 @@ struct plat_sci_port { 
	unsigned int	type;			/* SCI / SCIF / IRDA */

	upf_t		flags;			/* UPF_* flags */

	char		*clk;			/* clock string */

	struct device	*dma_dev;

	enum sh_dmae_slave_chan_id dma_slave_tx;

	enum sh_dmae_slave_chan_id dma_slave_rx;

};



#endif /* __LINUX_SERIAL_SCI_H */