i2c: rcar: refactor and shorten timeout when resetting

LOOP_TIMEOUT was only used back then because we didn't want to introduce
another constant. The timeout value can easily be a magnitude shorter
because the typical range is 3us - 8us. Refactor the code to use the
poll_timeout helper, use a specific timeout value and get rid of the
ugly LOOP_TIMEOUT constant.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drivers/i2c/busses/i2c-rcar.c

@@ -146,9 +146,6 @@ struct rcar_i2c_priv {
 #define rcar_i2c_priv_to_dev(p)		((p)->adap.dev.parent)
 #define rcar_i2c_is_recv(p)		((p)->msg->flags & I2C_M_RD)
 
-#define LOOP_TIMEOUT	1024
-
-
 static void rcar_i2c_write(struct rcar_i2c_priv *priv, int reg, u32 val)
 {
 	writel(val, priv->io + reg);
@@ -760,20 +757,14 @@ static void rcar_i2c_release_dma(struct rcar_i2c_priv *priv)
 /* I2C is a special case, we need to poll the status of a reset */
 static int rcar_i2c_do_reset(struct rcar_i2c_priv *priv)
 {
-	int i, ret;
+	int ret;
 
 	ret = reset_control_reset(priv->rstc);
 	if (ret)
 		return ret;
 
-	for (i = 0; i < LOOP_TIMEOUT; i++) {
-		ret = reset_control_status(priv->rstc);
-		if (ret == 0)
-			return 0;
-		udelay(1);
-	}
-
-	return -ETIMEDOUT;
+	return read_poll_timeout_atomic(reset_control_status, ret, ret == 0, 1,
+					100, false, priv->rstc);
 }
 
 static int rcar_i2c_master_xfer(struct i2c_adapter *adap,