i2c: add quirk checks to core (b7f62584) · Commits · 戴 / test

drivers/i2c/i2c-core.c

+62 −0

Original line number	Diff line number	Diff line
		@@ -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, "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
		@@ -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.

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