[PATCH 06/10] sata: ahci_da850: implement a softreset quirk

[Bartosz Golaszewski <bgolaszewski@baylibre.com>]

There's an issue with the da850 SATA controller: if port multiplier
support is compiled in, but we're connecting the drive directly to
the SATA port on the board, the drive can't be detected.

To make SATA work on the da850-lcdk board: first try to softreset
with pmp - if the operation fails with -EBUSY, retry without pmp.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 drivers/ata/ahci_da850.c | 22 +++++++++++++++++++++-
 1 file changed, 21 insertions(+), 1 deletion(-)

diff --git a/drivers/ata/ahci_da850.c b/drivers/ata/ahci_da850.c
index 5930af81..bb9eb4c 100644
--- a/drivers/ata/ahci_da850.c
+++ b/drivers/ata/ahci_da850.c
@@ -54,11 +54,31 @@ static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg,
 	writel(val, ahci_base + SATA_P0PHYCR_REG);
 }
 
+static int ahci_da850_softreset(struct ata_link *link,
+				unsigned int *class, unsigned long deadline)
+{
+	int pmp, ret;
+
+	pmp = sata_srst_pmp(link);
+
+	ret = ahci_do_softreset(link, class, pmp, deadline, ahci_check_ready);
+	if (pmp && ret == -EBUSY)
+		return ahci_do_softreset(link, class, 0,
+					 deadline, ahci_check_ready);
+
+	return ret;
+}
+
+static struct ata_port_operations ahci_da850_port_ops = {
+	.inherits = &ahci_platform_ops,
+	.softreset = ahci_da850_softreset,
+};
+
 static const struct ata_port_info ahci_da850_port_info = {
 	.flags		= AHCI_FLAG_COMMON,
 	.pio_mask	= ATA_PIO4,
 	.udma_mask	= ATA_UDMA6,
-	.port_ops	= &ahci_platform_ops,
+	.port_ops	= &ahci_da850_port_ops,
 };
 
 static struct scsi_host_template ahci_platform_sht = {
-- 
2.9.3