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[ig4] Rewrite ig4iic_write routine to use TX_EMPTY status flag

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rather than TX_NOTFULL. It makes possible interrupt utilization while
waiting for empty space in TX FIFO.
This commit is contained in:
Vladimir Kondratyev 2019-11-03 21:03:07 +00:00
parent 6f0c4b8583
commit 023c42edae
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=354310
1 changed files with 20 additions and 10 deletions
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30
sys/dev/ichiic/ig4_iic.c
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@ -384,21 +384,31 @@ ig4iic_write(ig4iic_softc_t *sc, uint8_t *buf, uint16_t len,
bool repeated_start, bool stop)
{
uint32_t cmd;
uint16_t i;
int sent = 0;
int burst, target;
int error;
if (len == 0)
return (0);
cmd = repeated_start ? IG4_DATA_RESTART : 0;
for (i = 0; i < len; i++) {
error = wait_status(sc, IG4_STATUS_TX_NOTFULL);
if (error)
break;
cmd |= buf[i];
cmd |= stop && i == len - 1 ? IG4_DATA_STOP : 0;
reg_write(sc, IG4_REG_DATA_CMD, cmd);
cmd = 0;
while (sent < len) {
burst = sc->cfg.txfifo_depth -
(reg_read(sc, IG4_REG_TXFLR) & IG4_FIFOLVL_MASK);
target = MIN(sent + burst, (int)len);
while(sent < target) {
cmd = buf[sent];
if (repeated_start && sent == 0)
cmd |= IG4_DATA_RESTART;
if (stop && sent == len - 1)
cmd |= IG4_DATA_STOP;
reg_write(sc, IG4_REG_DATA_CMD, cmd);
sent++;
}
if (sent < len) {
error = wait_status(sc, IG4_STATUS_TX_EMPTY);
if (error)
break;
}
}
(void)reg_read(sc, IG4_REG_TX_ABRT_SOURCE);