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Utilize the Keywest I2C combined mode for messages with repeated starts.

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This commit is contained in:
Nathan Whitehorn 2010-06-05 17:49:40 +00:00
parent fed318596c
commit c933841d14
1 changed files with 57 additions and 8 deletions
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65
sys/powerpc/powermac/kiic.c
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@ -107,6 +107,7 @@ struct kiic_softc {
u_int sc_flags;
u_char *sc_data;
int sc_resid;
uint16_t sc_i2c_base;
device_t sc_iicbus;
};
@ -114,6 +115,7 @@ static int kiic_probe(device_t dev);
static int kiic_attach(device_t dev);
static void kiic_writereg(struct kiic_softc *sc, u_int, u_int);
static u_int kiic_readreg(struct kiic_softc *, u_int);
static void kiic_setport(struct kiic_softc *, u_int);
static void kiic_setmode(struct kiic_softc *, u_int);
static void kiic_setspeed(struct kiic_softc *, u_int);
static void kiic_intr(void *xsc);
@ -196,12 +198,25 @@ kiic_attach(device_t self)
* underneath them. Some have a single 'iicbus' child with the
* devices underneath that. Sort this out, and make sure that the
* OFW I2C layer has the correct node.
*
* Note: the I2C children of the Uninorth bridges have two ports.
* In general, the port is designated in the 9th bit of the I2C
* address. However, for kiic devices with children attached below
* an i2c-bus node, the port is indicated in the 'reg' property
* of the i2c-bus node.
*/
sc->sc_node = OF_child(node);
if (OF_getprop(sc->sc_node,"name",name,sizeof(name)) > 0) {
if (strcmp(name,"i2c-bus") != 0)
sc->sc_node = node;
node = OF_child(node);
if (OF_getprop(node, "name", name, sizeof(name)) > 0) {
if (strcmp(name,"i2c-bus") == 0) {
phandle_t reg;
if (OF_getprop(node, "reg", &reg, sizeof(reg)) > 0)
sc->sc_i2c_base = reg << 8;
sc->sc_node = node;
}
}
mtx_init(&sc->sc_mutex, "kiic", NULL, MTX_DEF);
@ -211,8 +226,8 @@ kiic_attach(device_t self)
bus_setup_intr(self, sc->sc_irq, INTR_TYPE_MISC | INTR_MPSAFE, NULL,
kiic_intr, sc, &sc->sc_ih);
kiic_writereg(sc, ISR, kiic_readreg(sc, ISR));
kiic_writereg(sc, STATUS, 0);
kiic_writereg(sc, ISR, 0);
kiic_writereg(sc, IER, 0);
kiic_setmode(sc, I2C_STDMODE);
@ -251,6 +266,18 @@ kiic_setmode(struct kiic_softc *sc, u_int mode)
kiic_writereg(sc, MODE, x);
}
static void
kiic_setport(struct kiic_softc *sc, u_int port)
{
u_int x;
KASSERT(port == 1 || port == 0, ("bad port"));
x = kiic_readreg(sc, MODE);
x &= ~I2C_PORT;
x |= (port << 4);
kiic_writereg(sc, MODE, x);
}
static void
kiic_setspeed(struct kiic_softc *sc, u_int speed)
{
@ -294,7 +321,8 @@ kiic_intr(void *xsc)
*sc->sc_data++ = kiic_readreg(sc, DATA);
sc->sc_resid--;
}
if (sc->sc_resid == 0) /* done */
kiic_writereg(sc, CONTROL, 0);
} else {
if (sc->sc_resid == 0) {
x = kiic_readreg(sc, CONTROL);
@ -322,10 +350,12 @@ kiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
{
struct kiic_softc *sc;
int i, x, timo, err;
uint8_t addr;
uint16_t addr;
uint8_t subaddr;
sc = device_get_softc(dev);
timo = 100;
subaddr = 0;
mtx_lock(&sc->sc_mutex);
@ -339,7 +369,23 @@ kiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
sc->sc_flags = I2C_BUSY;
/* Clear pending interrupts, and reset controller */
kiic_writereg(sc, ISR, kiic_readreg(sc, ISR));
kiic_writereg(sc, STATUS, 0);
for (i = 0; i < nmsgs; i++) {
if (msgs[i].flags & IIC_M_NOSTOP) {
if (msgs[i+1].flags & IIC_M_RD)
kiic_setmode(sc, I2C_COMBMODE);
else
kiic_setmode(sc, I2C_STDSUBMODE);
KASSERT(msgs[i].len == 1, ("oversize I2C message"));
subaddr = msgs[i].buf[0];
i++;
} else {
kiic_setmode(sc, I2C_STDMODE);
}
sc->sc_data = msgs[i].buf;
sc->sc_resid = msgs[i].len;
sc->sc_flags = I2C_BUSY;
@ -352,8 +398,11 @@ kiic_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
addr |= 1;
}
kiic_writereg(sc, ADDR, addr);
kiic_writereg(sc, SUBADDR, 0x04);
addr |= sc->sc_i2c_base;
kiic_setport(sc, (addr & 0x100) >> 8);
kiic_writereg(sc, ADDR, addr & 0xff);
kiic_writereg(sc, SUBADDR, subaddr);
x = kiic_readreg(sc, CONTROL) | I2C_CT_ADDR;
kiic_writereg(sc, CONTROL, x);