Merge remote-tracking branch 'pm/linux-next'

[karo-tx-linux.git] / drivers / i2c / i2c-core.c

diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index c87c31387e2d83479f03c544d3952859974f87ec..30815eaebf389594fb1dfdfd07f02e607f5dde9a 100644 (file)
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1875,6 +1875,13 @@ static int __init i2c_init(void)
 {
        int retval;
 
+       retval = of_alias_get_highest_id("i2c");
+
+       down_write(&__i2c_board_lock);
+       if (retval >= __i2c_first_dynamic_bus_num)
+               __i2c_first_dynamic_bus_num = retval + 1;
+       up_write(&__i2c_board_lock);
+
        retval = bus_register(&i2c_bus_type);
        if (retval)
                return retval;
@@ -1926,6 +1933,65 @@ 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, "adapter 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 must be 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 must be read");
+
+                       if (q->flags & I2C_AQ_COMB_SAME_ADDR && msgs[0].addr != msgs[1].addr)
+                               return i2c_quirk_error(adap, &msgs[0], "comb msg only to same addr");
+
+                       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
@@ -1943,6 +2009,9 @@ 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.