diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-mpc.c')
-rw-r--r-- | drivers/i2c/busses/i2c-mpc.c | 38 |
1 files changed, 24 insertions, 14 deletions
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c index 53b8da6dbb23..6c698c10d3cd 100644 --- a/drivers/i2c/busses/i2c-mpc.c +++ b/drivers/i2c/busses/i2c-mpc.c @@ -119,23 +119,30 @@ static inline void writeccr(struct mpc_i2c *i2c, u32 x) /* Sometimes 9th clock pulse isn't generated, and slave doesn't release * the bus, because it wants to send ACK. * Following sequence of enabling/disabling and sending start/stop generates - * the 9 pulses, so it's all OK. + * the 9 pulses, each with a START then ending with STOP, so it's all OK. */ static void mpc_i2c_fixup(struct mpc_i2c *i2c) { int k; - u32 delay_val = 1000000 / i2c->real_clk + 1; - - if (delay_val < 2) - delay_val = 2; + unsigned long flags; for (k = 9; k; k--) { writeccr(i2c, 0); - writeccr(i2c, CCR_MSTA | CCR_MTX | CCR_MEN); + writeb(0, i2c->base + MPC_I2C_SR); /* clear any status bits */ + writeccr(i2c, CCR_MEN | CCR_MSTA); /* START */ + readb(i2c->base + MPC_I2C_DR); /* init xfer */ + udelay(15); /* let it hit the bus */ + local_irq_save(flags); /* should not be delayed further */ + writeccr(i2c, CCR_MEN | CCR_MSTA | CCR_RSTA); /* delay SDA */ readb(i2c->base + MPC_I2C_DR); - writeccr(i2c, CCR_MEN); - udelay(delay_val << 1); + if (k != 1) + udelay(5); + local_irq_restore(flags); } + writeccr(i2c, CCR_MEN); /* Initiate STOP */ + readb(i2c->base + MPC_I2C_DR); + udelay(15); /* Let STOP propagate */ + writeccr(i2c, 0); } static int i2c_mpc_wait_sr(struct mpc_i2c *i2c, int mask) @@ -492,7 +499,7 @@ static void mpc_i2c_finish(struct mpc_i2c *i2c, int rc) static void mpc_i2c_do_action(struct mpc_i2c *i2c) { - struct i2c_msg *msg = &i2c->msgs[i2c->curr_msg]; + struct i2c_msg *msg = NULL; int dir = 0; int recv_len = 0; u8 byte; @@ -501,10 +508,13 @@ static void mpc_i2c_do_action(struct mpc_i2c *i2c) i2c->cntl_bits &= ~(CCR_RSTA | CCR_MTX | CCR_TXAK); - if (msg->flags & I2C_M_RD) - dir = 1; - if (msg->flags & I2C_M_RECV_LEN) - recv_len = 1; + if (i2c->action != MPC_I2C_ACTION_STOP) { + msg = &i2c->msgs[i2c->curr_msg]; + if (msg->flags & I2C_M_RD) + dir = 1; + if (msg->flags & I2C_M_RECV_LEN) + recv_len = 1; + } switch (i2c->action) { case MPC_I2C_ACTION_RESTART: @@ -581,7 +591,7 @@ static void mpc_i2c_do_action(struct mpc_i2c *i2c) break; } - if (msg->len == i2c->byte_posn) { + if (msg && msg->len == i2c->byte_posn) { i2c->curr_msg++; i2c->byte_posn = 0; |