diff options
| author | Chew, Chiau Ee <chiau.ee.chew@intel.com> | 2013-06-21 11:05:28 +0400 |
|---|---|---|
| committer | Wolfram Sang <wsa@the-dreams.de> | 2013-08-07 18:58:07 +0400 |
| commit | 825642455367e5498da82a8044dd345ac7869c8d (patch) | |
| tree | 999b3a3e79b0b5cfb8059a54720127427bda4b7a /drivers/i2c | |
| parent | 9d3dda5c0d092d6bc9911bf24de81350d47c6be6 (diff) | |
| download | linux-825642455367e5498da82a8044dd345ac7869c8d.tar.xz | |
i2c: designware: Manually set RESTART bit between messages
If both IC_EMPTYFIFO_HOLD_MASTER_EN and IC_RESTART_EN are set to 1, the
Designware I2C controller doesn't generate RESTART unless user specifically
requests it by setting RESTART bit in IC_DATA_CMD register.
Since IC_EMPTYFIFO_HOLD_MASTER_EN setting can't be detected from hardware
register, we must always manually set the restart bit between messages.
Signed-off-by: Chew, Chiau Ee <chiau.ee.chew@intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-core.c | 14 |
1 files changed, 14 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-designware-core.c b/drivers/i2c/busses/i2c-designware-core.c index ad46616de29e..f325ec7abfb1 100644 --- a/drivers/i2c/busses/i2c-designware-core.c +++ b/drivers/i2c/busses/i2c-designware-core.c @@ -416,6 +416,7 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev) u32 addr = msgs[dev->msg_write_idx].addr; u32 buf_len = dev->tx_buf_len; u8 *buf = dev->tx_buf; + bool need_restart = false; intr_mask = DW_IC_INTR_DEFAULT_MASK; @@ -443,6 +444,14 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev) /* new i2c_msg */ buf = msgs[dev->msg_write_idx].buf; buf_len = msgs[dev->msg_write_idx].len; + + /* If both IC_EMPTYFIFO_HOLD_MASTER_EN and + * IC_RESTART_EN are set, we must manually + * set restart bit between messages. + */ + if ((dev->master_cfg & DW_IC_CON_RESTART_EN) && + (dev->msg_write_idx > 0)) + need_restart = true; } tx_limit = dev->tx_fifo_depth - dw_readl(dev, DW_IC_TXFLR); @@ -461,6 +470,11 @@ i2c_dw_xfer_msg(struct dw_i2c_dev *dev) buf_len == 1) cmd |= BIT(9); + if (need_restart) { + cmd |= BIT(10); + need_restart = false; + } + if (msgs[dev->msg_write_idx].flags & I2C_M_RD) { /* avoid rx buffer overrun */ |