[Skiboot] [RFC PATCH] i2c: Move tpm i2c wrapper code into core
Andrew Donnellan
andrew.donnellan at au1.ibm.com
Mon Aug 14 14:28:25 AEST 2017
The TPM code has a wrapper around the main i2c API to allow synchronous use.
Move it into core/i2c.c so it can be used by other possible users. In
particular, a future patch will use this to drive OpenCAPI device resets
during boot time.
Cc: Claudio Carvalho <cclaudio at linux.vnet.ibm.com>
Signed-off-by: Andrew Donnellan <andrew.donnellan at au1.ibm.com>
---
RFC till I get OpenCAPI ZZ card reset fully working
Claudio, I didn't manage to test this against a machine with a TPM due to
a TPM shortage in OzLabs. Please let me know if this causes any issues.
---
core/i2c.c | 107 +++++++++++++++++++++++++++++++++++++
include/i2c.h | 5 ++
libstb/drivers/tpm_i2c_interface.c | 105 ++++--------------------------------
libstb/drivers/tpm_i2c_interface.h | 1 -
4 files changed, 123 insertions(+), 95 deletions(-)
diff --git a/core/i2c.c b/core/i2c.c
index c1646249..d4311c27 100644
--- a/core/i2c.c
+++ b/core/i2c.c
@@ -19,6 +19,7 @@
#include <opal.h>
#include <device.h>
#include <opal-msg.h>
+#include <timebase.h>
static LIST_HEAD(i2c_bus_list);
@@ -134,4 +135,110 @@ static int opal_i2c_request(uint64_t async_token, uint32_t bus_id,
}
opal_call(OPAL_I2C_REQUEST, opal_i2c_request, 3);
+#define MAX_NACK_RETRIES 2
+#define REQ_COMPLETE_POLLING 5 /* Check if req is complete
+ in 5ms interval */
+struct i2c_sync_userdata {
+ int rc;
+ bool done;
+};
+
+static void i2c_sync_request_complete(int rc, struct i2c_request *req)
+{
+ struct i2c_sync_userdata *ud = req->user_data;
+ ud->rc = rc;
+ ud->done = true;
+}
+
+/**
+ * i2c_request_send - send request to i2c bus synchronously
+ * @bus_id: i2c bus id
+ * @dev_addr: address of the device
+ * @read_write: SMBUS_READ or SMBUS_WRITE
+ * @offset: any of the I2C interface offset defined
+ * @offset_bytes: offset size in bytes
+ * @buf: data to be read or written
+ * @buflen: buf length
+ * @timeout: request timeout in milliseconds
+ *
+ * Send an I2C request to a device synchronously
+ *
+ * Returns: Zero on success otherwise a negative error code
+ */
+int i2c_request_send(int bus_id, int dev_addr, int read_write,
+ uint32_t offset, uint32_t offset_bytes, void* buf,
+ size_t buflen, int timeout)
+{
+ int rc, waited, retries;
+ struct i2c_request *req;
+ struct i2c_bus *bus;
+ uint64_t time_to_wait = 0;
+ struct i2c_sync_userdata ud;
+
+ bus = i2c_find_bus_by_id(bus_id);
+ if (!bus) {
+ /**
+ * @fwts-label I2CInvalidBusID
+ * @fwts-advice i2c_request_send was passed an invalid bus
+ * ID. This indicates a bug.
+ */
+ prlog(PR_ERR, "I2C: Invalid bus_id=%x\n", bus_id);
+ return OPAL_PARAMETER;
+ }
+
+ req = i2c_alloc_req(bus);
+ if (!req) {
+ /**
+ * @fwts-label I2CAllocationFailed
+ * @fwts-advice OPAL failed to allocate memory for an
+ * i2c_request. This points to an OPAL bug as OPAL run out of
+ * memory and this should never happen.
+ */
+ prlog(PR_ERR, "I2C: i2c_alloc_req failed\n");
+ return OPAL_INTERNAL_ERROR;
+ }
+
+ req->dev_addr = dev_addr;
+ req->op = read_write;
+ req->offset = offset;
+ req->offset_bytes = offset_bytes;
+ req->rw_buf = (void*) buf;
+ req->rw_len = buflen;
+ req->completion = i2c_sync_request_complete;
+ ud.done = false;
+ req->user_data = &ud;
+
+ for (retries = 0; retries <= MAX_NACK_RETRIES; retries++) {
+ waited = 0;
+ i2c_set_req_timeout(req, timeout);
+ i2c_queue_req(req);
+
+ do {
+ time_to_wait = i2c_run_req(req);
+ if (!time_to_wait)
+ time_to_wait = REQ_COMPLETE_POLLING;
+ time_wait(time_to_wait);
+ waited += time_to_wait;
+ } while (!ud.done);
+
+ rc = ud.rc;
+
+ if (rc == OPAL_I2C_NACK_RCVD)
+ continue;
+ else
+ /* error or success */
+ break;
+ }
+
+ prlog(PR_DEBUG, "I2C: %s req op=%x offset=%x buf=%016llx buflen=%d "
+ "delay=%lu/%d rc=%d\n",
+ (rc) ? "!!!!" : "----", req->op, req->offset,
+ *(uint64_t*) buf, req->rw_len, tb_to_msecs(waited), timeout, rc);
+
+ i2c_free_req(req);
+ if (rc)
+ return OPAL_HARDWARE;
+
+ return OPAL_SUCCESS;
+}
diff --git a/include/i2c.h b/include/i2c.h
index e5e8584b..669c30a2 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -106,6 +106,11 @@ static inline int i2c_check_quirk(struct i2c_request *req, int *rc)
return 0;
}
+/* I2C synchronous request API */
+int i2c_request_send(int bus_id, int dev_addr, int read_write,
+ uint32_t offset, uint32_t offset_bytes, void* buf,
+ size_t buflen, int timeout);
+
/* P8 implementation details */
extern void p8_i2c_init(void);
extern void p8_i2c_interrupt(uint32_t chip_id);
diff --git a/libstb/drivers/tpm_i2c_interface.c b/libstb/drivers/tpm_i2c_interface.c
index cc7bf1ad..a6342e0c 100644
--- a/libstb/drivers/tpm_i2c_interface.c
+++ b/libstb/drivers/tpm_i2c_interface.c
@@ -15,32 +15,13 @@
*/
#include <skiboot.h>
-#include <timebase.h>
#include <opal-api.h>
#include <i2c.h>
#include "tpm_i2c_interface.h"
#include "../status_codes.h"
-//#define DBG(fmt, ...) prlog(PR_DEBUG, fmt, ##__VA_ARGS__)
-#define DBG(fmt, ...)
-
#define I2C_BYTE_TIMEOUT_MS 30 /* 30ms/byte timeout */
-#define TPM_MAX_NACK_RETRIES 2
-#define REQ_COMPLETE_POLLING 5 /* Check if req is complete
- in 5ms interval */
-
-struct tpm_i2c_userdata {
- int rc;
- bool done;
-};
-
-void tpm_i2c_request_complete(int rc, struct i2c_request *req)
-{
- struct tpm_i2c_userdata *ud = req->user_data;
- ud->rc = rc;
- ud->done = true;
-}
/**
* tpm_i2c_request_send - send request to i2c bus
@@ -57,88 +38,24 @@ void tpm_i2c_request_complete(int rc, struct i2c_request *req)
*
* Returns: Zero on success otherwise a negative error code
*/
-int tpm_i2c_request_send(int tpm_bus_id, int tpm_dev_addr, int read_write,
+int tpm_i2c_request_send(int bus_id, int dev_addr, int read_write,
uint32_t offset, uint32_t offset_bytes, void* buf,
size_t buflen)
{
- int rc, waited, retries, timeout;
- struct i2c_request *req;
- struct i2c_bus *bus;
- uint64_t time_to_wait = 0;
- struct tpm_i2c_userdata ud;
-
- bus = i2c_find_bus_by_id(tpm_bus_id);
- if (!bus) {
- /**
- * @fwts-label TPMI2CInvalidBusID
- * @fwts-advice tpm_i2c_request_send was passed an invalid bus
- * ID. This indicates a tb_init() bug.
- */
- prlog(PR_ERR, "TPM: Invalid bus_id=%x\n", tpm_bus_id);
- rc = STB_ARG_ERROR;
- goto out;
- }
-
- req = i2c_alloc_req(bus);
- if (!req) {
- /**
- * @fwts-label TPMI2CAllocationFailed
- * @fwts-advice OPAL failed to allocate memory for an
- * i2c_request. This points to an OPAL bug as OPAL run out of
- * memory and this should never happen.
- */
- prlog(PR_ERR, "TPM: i2c_alloc_req failed\n");
- rc = STB_DRIVER_ERROR;
- goto out;
- }
-
- req->dev_addr = tpm_dev_addr;
- req->op = read_write;
- req->offset = offset;
- req->offset_bytes = offset_bytes;
- req->rw_buf = (void*) buf;
- req->rw_len = buflen;
- req->completion = tpm_i2c_request_complete;
- ud.done = false;
- req->user_data = &ud;
+ int rc, timeout;
/*
- * Set the request timeout to 10ms per byte. Otherwise, we get
- * an I2C master timeout for all requests sent to the TPM device
+ * Set the request timeout to 30ms per byte. Otherwise, we get
+ * an I2C master timeout for all requests sent to the device
* since the I2C master's timeout is too short (1ms per byte).
*/
timeout = (buflen + offset_bytes + 2) * I2C_BYTE_TIMEOUT_MS;
- for (retries = 0; retries <= TPM_MAX_NACK_RETRIES; retries++) {
- waited = 0;
- i2c_set_req_timeout(req, timeout);
- i2c_queue_req(req);
-
- do {
- time_to_wait = i2c_run_req(req);
- if (!time_to_wait)
- time_to_wait = REQ_COMPLETE_POLLING;
- time_wait(time_to_wait);
- waited += time_to_wait;
- } while (!ud.done);
-
- rc = ud.rc;
-
- if (rc == OPAL_I2C_NACK_RCVD)
- continue;
- else
- /* error or success */
- break;
- }
-
- DBG("%s tpm req op=%x offset=%x buf=%016llx buflen=%d delay=%lu/%d,"
- "rc=%d\n",
- (rc) ? "!!!!" : "----", req->op, req->offset,
- *(uint64_t*) buf, req->rw_len, tb_to_msecs(waited), timeout, rc);
-
- i2c_free_req(req);
- if (rc)
- rc = STB_DRIVER_ERROR;
-out:
- return rc;
+ rc = i2c_request_send(bus_id, dev_addr, read_write, offset,
+ offset_bytes, buf, buflen, timeout);
+ if (rc == OPAL_PARAMETER)
+ return STB_ARG_ERROR;
+ else if (rc < 0)
+ return STB_DRIVER_ERROR;
+ return 0;
}
diff --git a/libstb/drivers/tpm_i2c_interface.h b/libstb/drivers/tpm_i2c_interface.h
index 0ac021ed..d2acc1ae 100644
--- a/libstb/drivers/tpm_i2c_interface.h
+++ b/libstb/drivers/tpm_i2c_interface.h
@@ -20,7 +20,6 @@
#include <i2c.h>
#include <stdlib.h>
-extern void tpm_i2c_request_complete(int rc, struct i2c_request *req);
extern int tpm_i2c_request_send(int tpm_bus_id, int tpm_dev_addr, int read_write,
uint32_t offset, uint32_t offset_bytes, void* buf,
size_t buflen);
--
2.11.0
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