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powerpc/powernv: Make opal_i2c driver work with attached i2c drivers

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* FreeBSD stores addresses in 8 bit format, but the OPAL API requires the 7-bit
  address, and encodes the direction elsewhere.  Behave like other i2c drivers,
  and shift accordingly.
* The OPAL API can already handle multiple requests in flight.  Change the async
  token to be private to the thread, so as not to stomp across i2c accesses,
  remove the limitation error message, and use the correct message index to
  transfer all messages in the list.
* Micro-optimize the async handler to not continuously call pmap_kextract() when
  spin-waiting for the operation to complete.

This has been tested by hexdumping an EEPROM attached via the icee(4) driver.
This commit is contained in:
Justin Hibbits 2018-07-09 20:33:48 +00:00
parent 51a8f735f8
commit 3395ab28eb
1 changed files with 11 additions and 15 deletions
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26
sys/powerpc/powernv/opal_i2c.c
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@ -167,16 +167,19 @@ static int
i2c_opal_send_request(uint32_t bus_id, struct opal_i2c_request *req)
{
struct opal_msg msg;
int token, rc;
uint64_t token;
uint64_t msg_addr;
int rc;
/*
* XXX:
* Async tokens should be managed globally. Since there is
* only one place now, use hardcoded value.
* Async tokens should be managed globally. Since there are only a very
* few places now, use a punning of the stack address of the message.
*/
token = 0x112233;
token = (uintptr_t)&msg;
memset(&msg, 0, sizeof(msg));
msg_addr = pmap_kextract((vm_offset_t)&msg);
rc = opal_call(OPAL_I2C_REQUEST, token, bus_id,
pmap_kextract((uint64_t)req));
@ -185,7 +188,7 @@ i2c_opal_send_request(uint32_t bus_id, struct opal_i2c_request *req)
do {
rc = opal_call(OPAL_CHECK_ASYNC_COMPLETION,
pmap_kextract((uint64_t)&msg), sizeof(msg), token);
msg_addr, sizeof(msg), token);
} while (rc == OPAL_BUSY);
if (rc != OPAL_SUCCESS)
@ -207,20 +210,13 @@ opal_i2c_transfer(device_t dev, struct iic_msg *msgs, uint32_t nmsgs)
memset(&req, 0, sizeof(req));
/* XXX: Currently OPAL can parse only 1 message */
if (nmsgs > 1) {
device_printf(dev,
"trying to parse %d messages, while only 1 is supported\n", nmsgs);
return (ENOMEM);
}
I2C_LOCK(sc);
for (i = 0; i < nmsgs; i++) {
req.type = (msgs[i].flags & IIC_M_RD) ?
OPAL_I2C_RAW_READ : OPAL_I2C_RAW_WRITE;
req.addr = htobe16(msgs[0].slave);
req.size = htobe32(msgs[0].len);
req.buffer_pa = htobe64(pmap_kextract((uint64_t)msgs[0].buf));
req.addr = htobe16(msgs[i].slave >> 1);
req.size = htobe32(msgs[i].len);
req.buffer_pa = htobe64(pmap_kextract((uint64_t)msgs[i].buf));
err = i2c_opal_send_request(sc->opal_id, &req);
}