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i2c: sh_mobile: send STOP according to datasheet

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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 <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Tested-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Wolfram Sang 2017-11-10 12:52:10 +01:00 committed by Wolfram Sang
parent 2967f9ca8b
commit a4fde7e5c9
1 changed files with 6 additions and 23 deletions
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29
drivers/i2c/busses/i2c-sh_mobile.c
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@ -40,21 +40,21 @@
/* BUS: S A8 ACK P(*) */ /* BUS: S A8 ACK P(*) */
/* IRQ: DTE WAIT */ /* IRQ: DTE WAIT */
/* ICIC: */ /* ICIC: */
/* ICCR: 0x94 0x90 */ /* ICCR: 0x94 0x90 */
/* ICDR: A8 */ /* ICDR: A8 */
/* */ /* */
/* 1 byte transmit */ /* 1 byte transmit */
/* BUS: S A8 ACK D8(1) ACK P(*) */ /* BUS: S A8 ACK D8(1) ACK P(*) */
/* IRQ: DTE WAIT WAIT */ /* IRQ: DTE WAIT WAIT */
/* ICIC: -DTE */ /* ICIC: -DTE */
/* ICCR: 0x94 0x90 */ /* ICCR: 0x94 0x90 */
/* ICDR: A8 D8(1) */ /* ICDR: A8 D8(1) */
/* */ /* */
/* 2 byte transmit */ /* 2 byte transmit */
/* BUS: S A8 ACK D8(1) ACK D8(2) ACK P(*) */ /* BUS: S A8 ACK D8(1) ACK D8(2) ACK P(*) */
/* IRQ: DTE WAIT WAIT WAIT */ /* IRQ: DTE WAIT WAIT WAIT */
/* ICIC: -DTE */ /* ICIC: -DTE */
/* ICCR: 0x94 0x90 */ /* ICCR: 0x94 0x90 */
/* ICDR: A8 D8(1) D8(2) */ /* ICDR: A8 D8(1) D8(2) */
/* */ /* */
/* 3 bytes or more, +---------+ gets repeated */ /* 3 bytes or more, +---------+ gets repeated */
@ -113,7 +113,6 @@ enum sh_mobile_i2c_op {
OP_TX_FIRST, OP_TX_FIRST,
OP_TX, OP_TX,
OP_TX_STOP, OP_TX_STOP,
OP_TX_STOP_DATA,
OP_TX_TO_RX, OP_TX_TO_RX,
OP_RX, OP_RX,
OP_RX_STOP, OP_RX_STOP,
@ -319,10 +318,7 @@ static unsigned char i2c_op(struct sh_mobile_i2c_data *pd,
case OP_TX: /* write data */ case OP_TX: /* write data */
iic_wr(pd, ICDR, data); iic_wr(pd, ICDR, data);
break; break;
case OP_TX_STOP_DATA: /* write data and issue a stop afterwards */ case OP_TX_STOP: /* issue a stop (or rep_start) */
iic_wr(pd, ICDR, data);
/* fallthrough */
case OP_TX_STOP: /* issue a stop */
iic_wr(pd, ICCR, pd->send_stop ? ICCR_ICE | ICCR_TRS iic_wr(pd, ICCR, pd->send_stop ? ICCR_ICE | ICCR_TRS
: ICCR_ICE | ICCR_TRS | ICCR_BBSY); : ICCR_ICE | ICCR_TRS | ICCR_BBSY);
break; break;
@ -356,11 +352,6 @@ static bool sh_mobile_i2c_is_first_byte(struct sh_mobile_i2c_data *pd)
return pd->pos == -1; 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, static void sh_mobile_i2c_get_data(struct sh_mobile_i2c_data *pd,
unsigned char *buf) unsigned char *buf)
{ {
@ -378,20 +369,12 @@ static int sh_mobile_i2c_isr_tx(struct sh_mobile_i2c_data *pd)
unsigned char data; unsigned char data;
if (pd->pos == pd->msg->len) { if (pd->pos == pd->msg->len) {
/* Send stop if we haven't yet (DMA case) */ i2c_op(pd, OP_TX_STOP, 0);
if (pd->send_stop && pd->stop_after_dma)
i2c_op(pd, OP_TX_STOP, 0);
return 1; return 1;
} }
sh_mobile_i2c_get_data(pd, &data); sh_mobile_i2c_get_data(pd, &data);
i2c_op(pd, sh_mobile_i2c_is_first_byte(pd) ? OP_TX_FIRST : OP_TX, 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);
pd->pos++; pd->pos++;
return 0; return 0;