[PATCH 4/4] Blackfin SPI driver: reconfigure speed_hz and bits_per_word in each spi transfer

From: Bryan Wu
Date: Thu Nov 01 2007 - 22:39:53 EST


- reconfigure SPI baud from speed_hz of each spi transfer
- according to spi_transfer.bits_per_word to reprogram register and setup
correct SPI operation handlers

Signed-off-by: Bryan Wu <bryan.wu@xxxxxxxxxx>
---
drivers/spi/spi_bfin5xx.c | 54 ++++++++++++++++++++++++++++++++++++++------
1 files changed, 46 insertions(+), 8 deletions(-)

diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
index f466fa0..3e5126e 100644
--- a/drivers/spi/spi_bfin5xx.c
+++ b/drivers/spi/spi_bfin5xx.c
@@ -234,10 +234,8 @@ static int restore_state(struct driver_data *drv_data)
dev_dbg(&drv_data->pdev->dev, "restoring spi ctl state\n");

/* Load the registers */
- write_BAUD(drv_data, chip->baud);
- chip->ctl_reg &= (~BIT_CTL_TIMOD);
- chip->ctl_reg |= (chip->width << 8);
write_CTRL(drv_data, chip->ctl_reg);
+ write_BAUD(drv_data, chip->baud);

bfin_spi_enable(drv_data);
cs_active(drv_data, chip);
@@ -679,6 +677,7 @@ static void pump_transfers(unsigned long data)
message = drv_data->cur_msg;
transfer = drv_data->cur_transfer;
chip = drv_data->cur_chip;
+
/*
* if msg is error or done, report it back using complete() callback
*/
@@ -736,23 +735,62 @@ static void pump_transfers(unsigned long data)
drv_data->len_in_bytes = transfer->len;
drv_data->cs_change = transfer->cs_change;

- width = chip->width;
+ /* Bits per word setup */
+ switch (transfer->bits_per_word) {
+ case 8:
+ drv_data->n_bytes = 1;
+ width = CFG_SPI_WORDSIZE8;
+ drv_data->read = chip->cs_change_per_word ?
+ u8_cs_chg_reader : u8_reader;
+ drv_data->write = chip->cs_change_per_word ?
+ u8_cs_chg_writer : u8_writer;
+ drv_data->duplex = chip->cs_change_per_word ?
+ u8_cs_chg_duplex : u8_duplex;
+ break;
+
+ case 16:
+ drv_data->n_bytes = 2;
+ width = CFG_SPI_WORDSIZE16;
+ drv_data->read = chip->cs_change_per_word ?
+ u16_cs_chg_reader : u16_reader;
+ drv_data->write = chip->cs_change_per_word ?
+ u16_cs_chg_writer : u16_writer;
+ drv_data->duplex = chip->cs_change_per_word ?
+ u16_cs_chg_duplex : u16_duplex;
+ break;
+
+ default:
+ /* No change, the same as default setting */
+ drv_data->n_bytes = chip->n_bytes;
+ width = chip->width;
+ drv_data->write = drv_data->tx ? chip->write : null_writer;
+ drv_data->read = drv_data->rx ? chip->read : null_reader;
+ drv_data->duplex = chip->duplex ? chip->duplex : null_writer;
+ break;
+ }
+ cr = (read_CTRL(drv_data) & (~BIT_CTL_TIMOD));
+ cr |= (width << 8);
+ write_CTRL(drv_data, cr);
+
if (width == CFG_SPI_WORDSIZE16) {
drv_data->len = (transfer->len) >> 1;
} else {
drv_data->len = transfer->len;
}
- drv_data->write = drv_data->tx ? chip->write : null_writer;
- drv_data->read = drv_data->rx ? chip->read : null_reader;
- drv_data->duplex = chip->duplex ? chip->duplex : null_writer;
dev_dbg(&drv_data->pdev->dev,
"transfer: drv_data->write is %p, chip->write is %p, null_wr is %p\n",
- drv_data->write, chip->write, null_writer);
+ drv_data->write, chip->write, null_writer);

/* speed and width has been set on per message */
message->state = RUNNING_STATE;
dma_config = 0;

+ /* Speed setup (surely valid because already checked) */
+ if (transfer->speed_hz)
+ write_BAUD(drv_data, hz_to_spi_baud(transfer->speed_hz));
+ else
+ write_BAUD(drv_data, chip->baud);
+
write_STAT(drv_data, BIT_STAT_CLR);
cr = (read_CTRL(drv_data) & (~BIT_CTL_TIMOD));
cs_active(drv_data, chip);
--
1.5.3.4
-
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