ata: ahci_tegra: Read calibration fuse

The original version of the driver did not read the SATA calibration
fuse to remove the dependency to the fuse driver. The fuse driver
is now merged, so add this functionality.

The calibration fuse contains a 2-bit value used to pick a set
of calibration values for the SATA pad.
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

drivers/ata/ahci_tegra.c

@@ -18,14 +18,17 @@
  */
 
 #include <linux/ahci_platform.h>
-#include <linux/reset.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/regulator/consumer.h>
+#include <linux/reset.h>
+
+#include <soc/tegra/fuse.h>
 #include <soc/tegra/pmc.h>
+
 #include "ahci.h"
 
 #define SATA_CONFIGURATION_0				0x180
@@ -180,9 +183,12 @@ static int tegra_ahci_controller_init(struct ahci_host_priv *hpriv)
 
 	/* Pad calibration */
 
-	/* FIXME Always use calibration 0. Change this to read the calibration
-	 * fuse once the fuse driver has landed. */
-	val = 0;
+	ret = tegra_fuse_readl(FUSE_SATA_CALIB, &val);
+	if (ret) {
+		dev_err(&tegra->pdev->dev,
+			"failed to read calibration fuse: %d\n", ret);
+		return ret;
+	}
 
 	calib = tegra124_pad_calibration[val & FUSE_SATA_CALIB_MASK];