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@xxxxxxxxxxxxx>
---
drivers/i2c/i2c-core.c | 53 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 53 insertions(+)
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 39d25a8cb1ad..7b10a19abf5b 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -2063,6 +2063,56 @@ 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(&adap->dev, "quirk: %s (addr 0x%04x, size %u)\n", err_msg, msg->addr, msg->len);
+ return -EOPNOTSUPP;
+}
+
+static int i2c_check_for_quirks(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ struct i2c_adapter_quirks *q = adap->quirks;
+ u16 max_read = q->max_read_len, max_write = q->max_write_len;
+ int max_num = q->max_num_msgs, i;
+
+ if (q->flags & I2C_ADAPTER_QUIRK_COMB_WRITE_THEN_READ)
+ max_num = 2;
+
+ if (i2c_quirk_exceeded(num, max_num))
+ return i2c_quirk_error(adap, &msgs[0], "too many messages");
+
+ if (num == 2 && q->flags & I2C_ADAPTER_QUIRK_COMB_WRITE_FIRST) {
+ if (msgs[0].flags & I2C_M_RD)
+ return i2c_quirk_error(adap, &msgs[0], "invalid first write msg");
+
+ max_write = q->max_comb_write_len;
+ }
+
+ if (num == 2 && q->flags & I2C_ADAPTER_QUIRK_COMB_READ_SECOND) {
+ if (!(msgs[1].flags & I2C_M_RD) || msgs[0].addr != msgs[1].addr)
+ return i2c_quirk_error(adap, &msgs[1], "invalid second read msg");
+
+ max_read = q->max_comb_read_len;
+ }
+
+ for (i = 0; i < num; i++) {
+ u16 len = msgs[i].len;
+
+ if (msgs[i].flags & I2C_M_RD) {
+ if (i2c_quirk_exceeded(len, max_read))
+ return i2c_quirk_error(adap, &msgs[i], "msg too long");
+ } else {
+ if (i2c_quirk_exceeded(len, max_write))
+ return i2c_quirk_error(adap, &msgs[i], "msg too long");
+ }
+ }
+
+ return 0;
+}
+
/**
* __i2c_transfer - unlocked flavor of i2c_transfer
* @adap: Handle to I2C bus
@@ -2080,6 +2130,9 @@ 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.
--
2.1.3
