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Commit fad91c89 authored by Bryan Wu's avatar Bryan Wu Committed by Linus Torvalds
Browse files

spi: spi_bfin handles spi_transfer.cs_change 



Respect per-transfer cs_change field (protocol tweaking support) by
adding and using cs_active/cs_deactive functions.

Signed-off-by: default avatarBryan Wu <bryan.wu@analog.com>
Signed-off-by: default avatarDavid Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5fec5b5a

drivers/spi/spi_bfin5xx.c

+54 −22
Original line number Diff line number Diff line
@@ -115,6 +115,7 @@ struct driver_data { 
	size_t rx_map_len;

	size_t tx_map_len;

	u8 n_bytes;

	int cs_change;

	void (*write) (struct driver_data *);

	void (*read) (struct driver_data *);

	void (*duplex) (struct driver_data *);
@@ -179,6 +180,26 @@ static int flush(struct driver_data *drv_data) 
	return limit;

}



/* Chip select operation functions for cs_change flag */

static void cs_active(struct chip_data *chip)

{

	u16 flag = read_FLAG();



	flag |= chip->flag;

	flag &= ~(chip->flag << 8);



	write_FLAG(flag);

}



static void cs_deactive(struct chip_data *chip)

{

	u16 flag = read_FLAG();



	flag |= (chip->flag << 8);



	write_FLAG(flag);

}



#define MAX_SPI0_SSEL	7



/* stop controller and re-config current chip*/
@@ -198,7 +219,7 @@ static int restore_state(struct driver_data *drv_data) 
	/* Load the registers */

	write_CTRL(chip->ctl_reg);

	write_BAUD(chip->baud);

	write_FLAG(chip->flag);

	cs_active(chip);



	if (!chip->chip_select_requested) {

		int i = chip->chip_select_num;
@@ -273,20 +294,20 @@ static void u8_cs_chg_writer(struct driver_data *drv_data) 
	struct chip_data *chip = drv_data->cur_chip;



	while (drv_data->tx < drv_data->tx_end) {

		write_FLAG(chip->flag);

		cs_active(chip);



		write_TDBR(*(u8 *) (drv_data->tx));

		while (read_STAT() & BIT_STAT_TXS)

			continue;

		while (!(read_STAT() & BIT_STAT_SPIF))

			continue;

		write_FLAG(0xFF00 | chip->flag);

		cs_deactive(chip);



		if (chip->cs_chg_udelay)

			udelay(chip->cs_chg_udelay);

		++drv_data->tx;

	}

	write_FLAG(0xFF00);

	cs_deactive(chip);



}
@@ -318,7 +339,7 @@ static void u8_cs_chg_reader(struct driver_data *drv_data) 
	struct chip_data *chip = drv_data->cur_chip;



	while (drv_data->rx < drv_data->rx_end) {

		write_FLAG(chip->flag);

		cs_active(chip);



		read_RDBR();	/* kick off */

		while (!(read_STAT() & BIT_STAT_RXS))
@@ -326,13 +347,13 @@ static void u8_cs_chg_reader(struct driver_data *drv_data) 
		while (!(read_STAT() & BIT_STAT_SPIF))

			continue;

		*(u8 *) (drv_data->rx) = read_SHAW();

		write_FLAG(0xFF00 | chip->flag);

		cs_deactive(chip);



		if (chip->cs_chg_udelay)

			udelay(chip->cs_chg_udelay);

		++drv_data->rx;

	}

	write_FLAG(0xFF00);

	cs_deactive(chip);



}
@@ -356,7 +377,7 @@ static void u8_cs_chg_duplex(struct driver_data *drv_data) 
	struct chip_data *chip = drv_data->cur_chip;



	while (drv_data->rx < drv_data->rx_end) {

		write_FLAG(chip->flag);

		cs_active(chip);





		write_TDBR(*(u8 *) (drv_data->tx));
@@ -365,15 +386,14 @@ static void u8_cs_chg_duplex(struct driver_data *drv_data) 
		while (!(read_STAT() & BIT_STAT_RXS))

			continue;

		*(u8 *) (drv_data->rx) = read_RDBR();

		write_FLAG(0xFF00 | chip->flag);

		cs_deactive(chip);



		if (chip->cs_chg_udelay)

			udelay(chip->cs_chg_udelay);

		++drv_data->rx;

		++drv_data->tx;

	}

	write_FLAG(0xFF00);



	cs_deactive(chip);

}



static void u16_writer(struct driver_data *drv_data)
@@ -398,20 +418,20 @@ static void u16_cs_chg_writer(struct driver_data *drv_data) 
	struct chip_data *chip = drv_data->cur_chip;



	while (drv_data->tx < drv_data->tx_end) {

		write_FLAG(chip->flag);

		cs_active(chip);



		write_TDBR(*(u16 *) (drv_data->tx));

		while ((read_STAT() & BIT_STAT_TXS))

			continue;

		while (!(read_STAT() & BIT_STAT_SPIF))

			continue;

		write_FLAG(0xFF00 | chip->flag);

		cs_deactive(chip);



		if (chip->cs_chg_udelay)

			udelay(chip->cs_chg_udelay);

		drv_data->tx += 2;

	}

	write_FLAG(0xFF00);

	cs_deactive(chip);

}



static void u16_reader(struct driver_data *drv_data)
@@ -438,7 +458,7 @@ static void u16_cs_chg_reader(struct driver_data *drv_data) 
	struct chip_data *chip = drv_data->cur_chip;



	while (drv_data->rx < drv_data->rx_end) {

		write_FLAG(chip->flag);

		cs_active(chip);



		read_RDBR();	/* kick off */

		while (!(read_STAT() & BIT_STAT_RXS))
@@ -446,13 +466,13 @@ static void u16_cs_chg_reader(struct driver_data *drv_data) 
		while (!(read_STAT() & BIT_STAT_SPIF))

			continue;

		*(u16 *) (drv_data->rx) = read_SHAW();

		write_FLAG(0xFF00 | chip->flag);

		cs_deactive(chip);



		if (chip->cs_chg_udelay)

			udelay(chip->cs_chg_udelay);

		drv_data->rx += 2;

	}

	write_FLAG(0xFF00);

	cs_deactive(chip);

}



static void u16_duplex(struct driver_data *drv_data)
@@ -475,7 +495,7 @@ static void u16_cs_chg_duplex(struct driver_data *drv_data) 
	struct chip_data *chip = drv_data->cur_chip;



	while (drv_data->tx < drv_data->tx_end) {

		write_FLAG(chip->flag);

		cs_active(chip);



		write_TDBR(*(u16 *) (drv_data->tx));

		while (!(read_STAT() & BIT_STAT_SPIF))
@@ -483,14 +503,14 @@ static void u16_cs_chg_duplex(struct driver_data *drv_data) 
		while (!(read_STAT() & BIT_STAT_RXS))

			continue;

		*(u16 *) (drv_data->rx) = read_RDBR();

		write_FLAG(0xFF00 | chip->flag);

		cs_deactive(chip);



		if (chip->cs_chg_udelay)

			udelay(chip->cs_chg_udelay);

		drv_data->rx += 2;

		drv_data->tx += 2;

	}

	write_FLAG(0xFF00);

	cs_deactive(chip);

}



/* test if ther is more transfer to be done */
@@ -515,6 +535,7 @@ static void *next_transfer(struct driver_data *drv_data) 
 */

static void giveback(struct driver_data *drv_data)

{

	struct chip_data *chip = drv_data->cur_chip;

	struct spi_transfer *last_transfer;

	unsigned long flags;

	struct spi_message *msg;
@@ -534,10 +555,13 @@ static void giveback(struct driver_data *drv_data) 


	/* disable chip select signal. And not stop spi in autobuffer mode */

	if (drv_data->tx_dma != 0xFFFF) {

		write_FLAG(0xFF00);

		cs_deactive(chip);

		bfin_spi_disable(drv_data);

	}



	if (!drv_data->cs_change)

		cs_deactive(chip);



	if (msg->complete)

		msg->complete(msg->context);

}
@@ -546,6 +570,7 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id) 
{

	struct driver_data *drv_data = (struct driver_data *)dev_id;

	struct spi_message *msg = drv_data->cur_msg;

	struct chip_data *chip = drv_data->cur_chip;



	dev_dbg(&drv_data->pdev->dev, "in dma_irq_handler\n");

	clear_dma_irqstat(CH_SPI);
@@ -573,6 +598,9 @@ static irqreturn_t dma_irq_handler(int irq, void *dev_id) 


	msg->actual_length += drv_data->len_in_bytes;



	if (drv_data->cs_change)

		cs_deactive(chip);



	/* Move to next transfer */

	msg->state = next_transfer(drv_data);
@@ -659,6 +687,7 @@ static void pump_transfers(unsigned long data) 
	drv_data->rx_dma = transfer->rx_dma;

	drv_data->tx_dma = transfer->tx_dma;

	drv_data->len_in_bytes = transfer->len;

	drv_data->cs_change = transfer->cs_change;



	width = chip->width;

	if (width == CFG_SPI_WORDSIZE16) {
@@ -683,7 +712,7 @@ static void pump_transfers(unsigned long data) 
	} else {

		write_BAUD(chip->baud);

	}

	write_FLAG(chip->flag);

	cs_active(chip);



	dev_dbg(&drv_data->pdev->dev,

		"now pumping a transfer: width is %d, len is %d\n",
@@ -834,6 +863,9 @@ static void pump_transfers(unsigned long data) 
			/* Update total byte transfered */

			message->actual_length += drv_data->len;



			if (drv_data->cs_change)

				cs_deactive(chip);



			/* Move to next transfer of this msg */

			message->state = next_transfer(drv_data);

		}