From: Bryan Wu Date: Wed, 6 Feb 2008 09:38:18 +0000 (-0800) Subject: spi_bfin: wait for tx to complete on some cs_chg paths X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e26aa015dd34d5768b80815836ad60e8495e9553;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git spi_bfin: wait for tx to complete on some cs_chg paths PBX 2 SPI devices need the nonstandard "cs change per word" mechanism. This patch is one of three updating this driver to make the last data bits get sent before advancing the transfer ... in this case, before the chipselect gets deactivated. Signed-off-by: Bryan Wu Signed-off-by: David Brownell Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c index 52beb5c924b7..ce4692cdb3b2 100644 --- a/drivers/spi/spi_bfin5xx.c +++ b/drivers/spi/spi_bfin5xx.c @@ -294,16 +294,14 @@ static void u8_cs_chg_writer(struct driver_data *drv_data) { struct chip_data *chip = drv_data->cur_chip; - /* poll for SPI completion before start */ - while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) - cpu_relax(); - while (drv_data->tx < drv_data->tx_end) { cs_active(drv_data, chip); write_TDBR(drv_data, (*(u8 *) (drv_data->tx))); while (read_STAT(drv_data) & BIT_STAT_TXS) cpu_relax(); + while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) + cpu_relax(); cs_deactive(drv_data, chip); @@ -342,31 +340,20 @@ static void u8_cs_chg_reader(struct driver_data *drv_data) { struct chip_data *chip = drv_data->cur_chip; - /* poll for SPI completion before start */ - while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) - cpu_relax(); - - /* clear TDBR buffer before read(else it will be shifted out) */ - write_TDBR(drv_data, 0xFFFF); + while (drv_data->rx < drv_data->rx_end) { + cs_active(drv_data, chip); + read_RDBR(drv_data); /* kick off */ - cs_active(drv_data, chip); - dummy_read(drv_data); + while (!(read_STAT(drv_data) & BIT_STAT_RXS)) + cpu_relax(); + while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) + cpu_relax(); - while (drv_data->rx < drv_data->rx_end - 1) { + *(u8 *) (drv_data->rx) = read_SHAW(drv_data); cs_deactive(drv_data, chip); - while (!(read_STAT(drv_data) & BIT_STAT_RXS)) - cpu_relax(); - cs_active(drv_data, chip); - *(u8 *) (drv_data->rx) = read_RDBR(drv_data); ++drv_data->rx; } - cs_deactive(drv_data, chip); - - while (!(read_STAT(drv_data) & BIT_STAT_RXS)) - cpu_relax(); - *(u8 *) (drv_data->rx) = read_SHAW(drv_data); - ++drv_data->rx; } static void u8_duplex(struct driver_data *drv_data) @@ -392,15 +379,12 @@ static void u8_cs_chg_duplex(struct driver_data *drv_data) { struct chip_data *chip = drv_data->cur_chip; - /* poll for SPI completion before start */ - while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) - cpu_relax(); - while (drv_data->rx < drv_data->rx_end) { cs_active(drv_data, chip); write_TDBR(drv_data, (*(u8 *) (drv_data->tx))); - while (read_STAT(drv_data) & BIT_STAT_TXS) + + while (!(read_STAT(drv_data) & BIT_STAT_SPIF)) cpu_relax(); while (!(read_STAT(drv_data) & BIT_STAT_RXS)) cpu_relax();