/**
* twl_scan - scans the i2c bus for sub modules
* @dev: the twl device
*
* TWL devices don't just have one i2c slave address, rather they have up to
* 5 other addresses, each is for separate modules within the device. This
* function scans the bus for 4 possible sub-devices and stores the info
* internally.
*
*/
static void
twl_scan(void *dev)
{
struct twl_softc *sc;
unsigned i;
uint8_t devs[TWL_MAX_SUBADDRS];
uint8_t base = TWL_CHIP_ID0;
sc = device_get_softc((device_t)dev);
memset(devs, TWL_INVALID_CHIP_ID, TWL_MAX_SUBADDRS);
/* Try each of the addresses (0x48, 0x49, 0x4a & 0x4b) to determine which
* sub modules we have.
*/
for (i = 0; i < TWL_MAX_SUBADDRS; i++) {
if (twl_test_present(sc, (base + i)) == 0) {
devs[i] = (base + i);
device_printf(sc->sc_dev, "Found (sub)device at 0x%02x\n", (base + i));
}
}
TWL_LOCK(sc);
memcpy(sc->sc_subaddr_map, devs, TWL_MAX_SUBADDRS);
TWL_UNLOCK(sc);
/* Finished with the interrupt hook */
config_intrhook_disestablish(&sc->sc_scan_hook);
}
/**
* twl_write - writes one or more registers to the TWL device
* @sc: device soft context
* @nsub: the sub-module to read from
* @reg: the register offset within the module to read
* @buf: data to write
* @cnt: the number of bytes to write
*
* Writes one or more registers.
*
* LOCKING:
* Expects the TWL lock to be held.
*
* RETURNS:
* Zero on success or a negative error code on failure.
*/
int
twl_write(device_t dev, uint8_t nsub, uint8_t reg, uint8_t *buf, uint16_t cnt)
{
struct twl_softc *sc;
struct iic_msg msg;
uint8_t addr;
uint8_t tmp_buf[TWL_MAX_IIC_DATA_SIZE + 1];
int rc;
if (cnt > TWL_MAX_IIC_DATA_SIZE)
return (ENOMEM);
/* Set the register address as the first byte */
tmp_buf[0] = reg;
memcpy(&tmp_buf[1], buf, cnt);
sc = device_get_softc(dev);
TWL_LOCK(sc);
addr = sc->sc_subaddr_map[nsub];
if (addr == TWL_INVALID_CHIP_ID) {
TWL_UNLOCK(sc);
return (EIO);
}
/* Setup the transfer and execute it */
msg.slave = addr;
msg.flags = IIC_M_WR;
msg.len = cnt + 1;
msg.buf = tmp_buf;
TWL_UNLOCK(sc);
rc = iicbus_transfer(dev, &msg, 1);
if (rc != 0) {
device_printf(sc->sc_dev, "iicbus write failed (adr:0x%02x, reg:0x%02x)\n",
addr, reg);
return (EIO);
}
return (0);
}
/**
* twl_read - read one or more registers from the TWL device
* @sc: device soft context
* @nsub: the sub-module to read from
* @reg: the register offset within the module to read
* @buf: buffer to store the bytes in
* @cnt: the number of bytes to read
*
* Reads one or registers and stores the result in the suppled buffer.
*
* LOCKING:
* Expects the TWL lock to be held.
*
* RETURNS:
* Zero on success or a negative error code on failure.
*/
int
twl_read(device_t dev, uint8_t nsub, uint8_t reg, uint8_t *buf, uint16_t cnt)
{
struct twl_softc *sc;
struct iic_msg msg[2];
uint8_t addr;
int rc;
sc = device_get_softc(dev);
TWL_LOCK(sc);
addr = sc->sc_subaddr_map[nsub];
if (addr == TWL_INVALID_CHIP_ID) {
TWL_UNLOCK(sc);
return (EIO);
}
/* Set the address to read from */
msg[0].slave = addr;
msg[0].flags = IIC_M_WR | IIC_M_NOSTOP;
msg[0].len = 1;
msg[0].buf = ®
/* Read the data back */
msg[1].slave = addr;
msg[1].flags = IIC_M_RD;
msg[1].len = cnt;
msg[1].buf = buf;
TWL_UNLOCK(sc);
rc = iicbus_transfer(dev, msg, 2);
if (rc != 0) {
device_printf(dev, "iicbus read failed (adr:0x%02x, reg:0x%02x)\n",
addr, reg);
return (EIO);
}
return (0);
}
