From fad91c890909aabab0d9858d50f3c8394ee16b21 Mon Sep 17 00:00:00 2001 From: Bryan Wu Date: Tue, 4 Dec 2007 23:45:14 -0800 Subject: [PATCH] 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: Bryan Wu Signed-off-by: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/spi/spi_bfin5xx.c | 76 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 54 insertions(+), 22 deletions(-) diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c index 803c5b2..c2d51cf 100644 --- a/drivers/spi/spi_bfin5xx.c +++ b/drivers/spi/spi_bfin5xx.c @@ -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); } -- 2.7.4