sf: atmel: undo unification of status polling

The AT45 flashes are completely different (at the command set and
status register level) from all other SPI flashes, so we can't unify
their logic with common code.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

drivers/mtd/spi/atmel.c

@@ -113,8 +113,35 @@ static const struct atmel_spi_flash_params atmel_spi_flash_table[] = {
 
 static int at45_wait_ready(struct spi_flash *flash, unsigned long timeout)
 {
-	return spi_flash_cmd_poll_bit(flash, timeout,
-		CMD_AT45_READ_STATUS, AT45_STATUS_READY);
+	struct spi_slave *spi = flash->spi;
+	unsigned long timebase;
+	int ret;
+	u8 cmd = CMD_AT45_READ_STATUS;
+	u8 status;
+
+	timebase = get_timer(0);
+
+	ret = spi_xfer(spi, 8, &cmd, NULL, SPI_XFER_BEGIN);
+	if (ret)
+		return -1;
+
+	do {
+		ret = spi_xfer(spi, 8, NULL, &status, 0);
+		if (ret)
+			return -1;
+
+		if (status & AT45_STATUS_READY)
+			break;
+	} while (get_timer(timebase) < timeout);
+
+	/* Deactivate CS */
+	spi_xfer(spi, 0, NULL, NULL, SPI_XFER_END);
+
+	if (status & AT45_STATUS_READY)
+		return 0;
+
+	/* Timed out */
+	return -1;
 }
 
 /*