From aee2c3a86af72e72a234be611dd4d5161fdb1782 Mon Sep 17 00:00:00 2001 From: Luiz Otavio O Souza Date: Tue, 20 Jun 2017 18:38:51 +0000 Subject: [PATCH] Always ignore the START and STOP bits whenever the control register is being overwritten, they are set only bits (cleared by hardware). Disable the Acknowledge of the controller slave address. The slave mode is not supported. Make sure the interrupt flag bit is being cleared as recommended, add a delay() _after_ clear the interrupt bit. Sponsored by: Rubicon Communications, LLC (Netgate) --- sys/dev/iicbus/twsi/twsi.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/sys/dev/iicbus/twsi/twsi.c b/sys/dev/iicbus/twsi/twsi.c index dee0b7a77d94..aa5f94373a70 100644 --- a/sys/dev/iicbus/twsi/twsi.c +++ b/sys/dev/iicbus/twsi/twsi.c @@ -114,6 +114,7 @@ twsi_control_clear(struct twsi_softc *sc, uint32_t mask) uint32_t val; val = TWSI_READ(sc, sc->reg_control); + val &= ~(TWSI_CONTROL_STOP | TWSI_CONTROL_START); val &= ~mask; TWSI_WRITE(sc, sc->reg_control, val); } @@ -124,6 +125,7 @@ twsi_control_set(struct twsi_softc *sc, uint32_t mask) uint32_t val; val = TWSI_READ(sc, sc->reg_control); + val &= ~(TWSI_CONTROL_STOP | TWSI_CONTROL_START); val |= mask; TWSI_WRITE(sc, sc->reg_control, val); } @@ -204,8 +206,8 @@ twsi_locked_start(device_t dev, struct twsi_softc *sc, int32_t mask, } TWSI_WRITE(sc, sc->reg_data, slave); - DELAY(1000); twsi_clear_iflg(sc); + DELAY(1000); if (twsi_poll_ctrl(sc, timeout, TWSI_CONTROL_IFLG)) { debugf("timeout sending slave address\n"); @@ -251,7 +253,7 @@ twsi_reset(device_t dev, u_char speed, u_char addr, u_char *oldaddr) TWSI_WRITE(sc, sc->reg_soft_reset, 0x0); DELAY(2000); TWSI_WRITE(sc, sc->reg_baud_rate, param); - TWSI_WRITE(sc, sc->reg_control, TWSI_CONTROL_TWSIEN | TWSI_CONTROL_ACK); + TWSI_WRITE(sc, sc->reg_control, TWSI_CONTROL_TWSIEN); DELAY(1000); mtx_unlock(&sc->mutex); @@ -266,9 +268,10 @@ twsi_stop(device_t dev) sc = device_get_softc(dev); mtx_lock(&sc->mutex); + twsi_control_clear(sc, TWSI_CONTROL_ACK); twsi_control_set(sc, TWSI_CONTROL_STOP); - DELAY(1000); twsi_clear_iflg(sc); + DELAY(1000); mtx_unlock(&sc->mutex); return (IIC_NOERR); @@ -341,8 +344,8 @@ twsi_read(device_t dev, char *buf, int len, int *read, int last, int delay) else twsi_control_set(sc, TWSI_CONTROL_ACK); - DELAY (1000); twsi_clear_iflg(sc); + DELAY(1000); if (twsi_poll_ctrl(sc, delay, TWSI_CONTROL_IFLG)) { debugf("timeout reading data\n"); @@ -382,6 +385,7 @@ twsi_write(device_t dev, const char *buf, int len, int *sent, int timeout) TWSI_WRITE(sc, sc->reg_data, *buf++); twsi_clear_iflg(sc); + DELAY(1000); if (twsi_poll_ctrl(sc, timeout, TWSI_CONTROL_IFLG)) { debugf("timeout writing data\n"); rv = IIC_ETIMEOUT;