From: Wolfram Sang <wsa+rene...@sang-engineering.com>
Let the core do the checks if HW quirks prevent a transfer. Saves code
from drivers and adds consistency.
Signed-off-by: Wolfram Sang <wsa+rene...@sang-engineering.com>
---
drivers/i2c/i2c-core.c | 62 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 62 insertions(+)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 210cf4874cb7ea..c5ca0e4006edb7 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1929,6 +1929,65 @@ module_exit(i2c_exit);
* ----------------------------------------------------
*/
+/* Check if val is exceeding the quirk IFF quirk is non 0 */
+#define i2c_quirk_exceeded(val, quirk) ((quirk) && ((val) > (quirk)))
+
+static int i2c_quirk_error(struct i2c_adapter *adap, struct i2c_msg *msg, char
*err_msg)
+{
+ dev_err_ratelimited(&adap->dev, "quirk: %s (addr 0x%04x, size %u,
%s)\n",
+ err_msg, msg->addr, msg->len,
+ msg->flags & I2C_M_RD ? "read" : "write");
+ return -EOPNOTSUPP;
+}
+
+static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg
*msgs, int num)
+{
+ const struct i2c_adapter_quirks *q = adap->quirks;
+ int max_num = q->max_num_msgs, i;
+ bool do_len_check = true;
+
+ if (q->flags & I2C_AQ_COMB) {
+ max_num = 2;
+
+ /* special checks for combined messages */
+ if (num == 2) {
+ if (q->flags & I2C_AQ_COMB_WRITE_FIRST && msgs[0].flags
& I2C_M_RD)
+ return i2c_quirk_error(adap, &msgs[0], "1st
comb msg not write");
+
+ if (q->flags & I2C_AQ_COMB_READ_SECOND &&
!(msgs[1].flags & I2C_M_RD))
+ return i2c_quirk_error(adap, &msgs[1], "2nd
comb msg not read");
+
+ if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr !=
msgs[1].addr)
+ return i2c_quirk_error(adap, &msgs[0],
"addresses do not match");
+
+ if (i2c_quirk_exceeded(msgs[0].len,
q->max_comb_1st_msg_len))
+ return i2c_quirk_error(adap, &msgs[0], "msg too
long");
+
+ if (i2c_quirk_exceeded(msgs[1].len,
q->max_comb_2nd_msg_len))
+ return i2c_quirk_error(adap, &msgs[1], "msg too
long");
+
+ do_len_check = false;
+ }
+ }
+
+ if (i2c_quirk_exceeded(num, max_num))
+ return i2c_quirk_error(adap, &msgs[0], "too many messages");
+
+ for (i = 0; i < num; i++) {
+ u16 len = msgs[i].len;
+
+ if (msgs[i].flags & I2C_M_RD) {
+ if (do_len_check && i2c_quirk_exceeded(len,
q->max_read_len))
+ return i2c_quirk_error(adap, &msgs[i], "msg too
long");
+ } else {
+ if (do_len_check && i2c_quirk_exceeded(len,
q->max_write_len))
+ return i2c_quirk_error(adap, &msgs[i], "msg too
long");
+ }
+ }
+
+ return 0;
+}
+
/**
* __i2c_transfer - unlocked flavor of i2c_transfer
* @adap: Handle to I2C bus
@@ -1946,6 +2005,9 @@ int __i2c_transfer(struct i2c_adapter *adap, struct
i2c_msg *msgs, int num)
unsigned long orig_jiffies;
int ret, try;
+ if (adap->quirks && i2c_check_for_quirks(adap, msgs, num))
+ return -EOPNOTSUPP;
+
/* i2c_trace_msg gets enabled when tracepoint i2c_transfer gets
* enabled. This is an efficient way of keeping the for-loop from
* being executed when not needed.
--
2.1.4
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