Commit 62310e51 authored by Bryan Wu's avatar Bryan Wu Committed by Linus Torvalds

spi: spi_bfin: update handling of delay-after-deselect

Move cs_chg_udelay handling (specific to this driver) to cs_deactive(), fixing
a bug when some SPI LCD driver needs delay after cs_deactive.

Fix bug reported by Cameron Barfield <cbarfield@cyberdata.net>
https://blackfin.uclinux.org/gf/project/uclinux-dist/forum/?action=ForumBrowse&forum_id=39&_forum_action=ForumMessageBrowse&thread_id=23630&feedback=Message%20replied.

Cc: Cameron Barfield <cbarfield@cyberdata.net>
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 c3061abb
......@@ -132,7 +132,7 @@ struct chip_data {
u8 enable_dma;
u8 bits_per_word; /* 8 or 16 */
u8 cs_change_per_word;
u8 cs_chg_udelay;
u16 cs_chg_udelay; /* Some devices require > 255usec delay */
void (*write) (struct driver_data *);
void (*read) (struct driver_data *);
void (*duplex) (struct driver_data *);
......@@ -211,6 +211,10 @@ static void cs_deactive(struct driver_data *drv_data, struct chip_data *chip)
flag |= (chip->flag << 8);
write_FLAG(drv_data, flag);
/* Move delay here for consistency */
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
}
#define MAX_SPI_SSEL 7
......@@ -307,10 +311,9 @@ static void u8_cs_chg_writer(struct driver_data *drv_data)
write_TDBR(drv_data, (*(u8 *) (drv_data->tx)));
while (read_STAT(drv_data) & BIT_STAT_TXS)
continue;
cs_deactive(drv_data, chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
++drv_data->tx;
}
}
......@@ -359,9 +362,6 @@ static void u8_cs_chg_reader(struct driver_data *drv_data)
while (drv_data->rx < drv_data->rx_end - 1) {
cs_deactive(drv_data, chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue;
cs_active(drv_data, chip);
......@@ -412,10 +412,9 @@ static void u8_cs_chg_duplex(struct driver_data *drv_data)
while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue;
*(u8 *) (drv_data->rx) = read_RDBR(drv_data);
cs_deactive(drv_data, chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
++drv_data->rx;
++drv_data->tx;
}
......@@ -452,10 +451,9 @@ static void u16_cs_chg_writer(struct driver_data *drv_data)
write_TDBR(drv_data, (*(u16 *) (drv_data->tx)));
while ((read_STAT(drv_data) & BIT_STAT_TXS))
continue;
cs_deactive(drv_data, chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
drv_data->tx += 2;
}
}
......@@ -504,9 +502,6 @@ static void u16_cs_chg_reader(struct driver_data *drv_data)
while (drv_data->rx < drv_data->rx_end - 2) {
cs_deactive(drv_data, chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue;
cs_active(drv_data, chip);
......@@ -557,10 +552,9 @@ static void u16_cs_chg_duplex(struct driver_data *drv_data)
while (!(read_STAT(drv_data) & BIT_STAT_RXS))
continue;
*(u16 *) (drv_data->rx) = read_RDBR(drv_data);
cs_deactive(drv_data, chip);
if (chip->cs_chg_udelay)
udelay(chip->cs_chg_udelay);
drv_data->rx += 2;
drv_data->tx += 2;
}
......
......@@ -162,7 +162,7 @@ struct bfin5xx_spi_chip {
u8 enable_dma;
u8 bits_per_word;
u8 cs_change_per_word;
u8 cs_chg_udelay;
u16 cs_chg_udelay; /* Some devices require 16-bit delays */
};
#endif /* _SPI_CHANNEL_H_ */
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