From a4fde7e5c9d6432ba863ee53debf27f10b370678 Mon Sep 17 00:00:00 2001 From: Wolfram Sang Date: Fri, 10 Nov 2017 12:52:10 +0100 Subject: [PATCH] i2c: sh_mobile: send STOP according to datasheet MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit We initiate STOP (or REP_START) on the second last WAIT interrupt currently. This works fine but is not according to the datasheet which says to do it on the last WAIT interrupt. This also simplifies the code quite a lot, so let's do it. Signed-off-by: Wolfram Sang Reviewed-by: Niklas Söderlund Tested-by: Jacopo Mondi Signed-off-by: Wolfram Sang --- drivers/i2c/busses/i2c-sh_mobile.c | 29 ++++++----------------------- 1 file changed, 6 insertions(+), 23 deletions(-) diff --git a/drivers/i2c/busses/i2c-sh_mobile.c b/drivers/i2c/busses/i2c-sh_mobile.c index 40a66d466c3c..c904be631db3 100644 --- a/drivers/i2c/busses/i2c-sh_mobile.c +++ b/drivers/i2c/busses/i2c-sh_mobile.c @@ -40,21 +40,21 @@ /* BUS: S A8 ACK P(*) */ /* IRQ: DTE WAIT */ /* ICIC: */ -/* ICCR: 0x94 0x90 */ +/* ICCR: 0x94 0x90 */ /* ICDR: A8 */ /* */ /* 1 byte transmit */ /* BUS: S A8 ACK D8(1) ACK P(*) */ /* IRQ: DTE WAIT WAIT */ /* ICIC: -DTE */ -/* ICCR: 0x94 0x90 */ +/* ICCR: 0x94 0x90 */ /* ICDR: A8 D8(1) */ /* */ /* 2 byte transmit */ /* BUS: S A8 ACK D8(1) ACK D8(2) ACK P(*) */ /* IRQ: DTE WAIT WAIT WAIT */ /* ICIC: -DTE */ -/* ICCR: 0x94 0x90 */ +/* ICCR: 0x94 0x90 */ /* ICDR: A8 D8(1) D8(2) */ /* */ /* 3 bytes or more, +---------+ gets repeated */ @@ -113,7 +113,6 @@ enum sh_mobile_i2c_op { OP_TX_FIRST, OP_TX, OP_TX_STOP, - OP_TX_STOP_DATA, OP_TX_TO_RX, OP_RX, OP_RX_STOP, @@ -319,10 +318,7 @@ static unsigned char i2c_op(struct sh_mobile_i2c_data *pd, case OP_TX: /* write data */ iic_wr(pd, ICDR, data); break; - case OP_TX_STOP_DATA: /* write data and issue a stop afterwards */ - iic_wr(pd, ICDR, data); - /* fallthrough */ - case OP_TX_STOP: /* issue a stop */ + case OP_TX_STOP: /* issue a stop (or rep_start) */ iic_wr(pd, ICCR, pd->send_stop ? ICCR_ICE | ICCR_TRS : ICCR_ICE | ICCR_TRS | ICCR_BBSY); break; @@ -356,11 +352,6 @@ static bool sh_mobile_i2c_is_first_byte(struct sh_mobile_i2c_data *pd) return pd->pos == -1; } -static bool sh_mobile_i2c_is_last_byte(struct sh_mobile_i2c_data *pd) -{ - return pd->pos == pd->msg->len - 1; -} - static void sh_mobile_i2c_get_data(struct sh_mobile_i2c_data *pd, unsigned char *buf) { @@ -378,20 +369,12 @@ static int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd) unsigned char data; if (pd->pos == pd->msg->len) { - /* Send stop if we haven't yet (DMA case) */ - if (pd->send_stop && pd->stop_after_dma) - i2c_op(pd, OP_TX_STOP, 0); + i2c_op(pd, OP_TX_STOP, 0); return 1; } sh_mobile_i2c_get_data(pd, &data); - - if (sh_mobile_i2c_is_last_byte(pd)) - i2c_op(pd, OP_TX_STOP_DATA, data); - else if (sh_mobile_i2c_is_first_byte(pd)) - i2c_op(pd, OP_TX_FIRST, data); - else - i2c_op(pd, OP_TX, data); + i2c_op(pd, sh_mobile_i2c_is_first_byte(pd) ? OP_TX_FIRST : OP_TX, data); pd->pos++; return 0; -- GitLab