ahci: mediatek: add ahci driver

add AHCI driver ported from linux

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/ata/ahci_mtk.c

Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
diff --git a/drivers/ata/mtk_ahci.c b/drivers/ata/mtk_ahci.c
new file mode 100644
index 0000000..8e09c5f
--- /dev/null
+++ b/drivers/ata/mtk_ahci.c
@@ -0,0 +1,130 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * MTK SATA platform driver
+ *
+ * (C) Copyright 2020
+ *     Mediatek
+ *
+ * Author: Frank Wunderlich <frank-w@public-files.de>
+ * based on https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/ata/ahci_mtk.c
+ * Author: Ryder Lee <ryder.lee@mediatek.com>
+ */
+
+#include <common.h>
+#include <ahci.h>
+#include <asm/io.h>
+#include <dm.h>
+#include <dm/of_access.h>
+#include <generic-phy.h>
+#include <linux/err.h>
+#include <regmap.h>
+#include <reset.h>
+#include <sata.h>
+#include <scsi.h>
+#include <syscon.h>
+
+#define SYS_CFG			0x14
+#define SYS_CFG_SATA_MSK	GENMASK(31, 30)
+#define SYS_CFG_SATA_EN		BIT(31)
+
+struct mtk_ahci_priv {
+	void *base;
+
+	struct ahci_uc_priv ahci_priv;
+	struct regmap *mode;
+	struct reset_ctl_bulk rst_bulk;
+};
+
+static int mtk_ahci_bind(struct udevice *dev)
+{
+	struct udevice *scsi_dev;
+
+	return ahci_bind_scsi(dev, &scsi_dev);
+}
+
+static int mtk_ahci_ofdata_to_platdata(struct udevice *dev)
+{
+	struct mtk_ahci_priv *priv = dev_get_priv(dev);
+
+	priv->base = devfdt_remap_addr_index(dev, 0);
+
+	return 0;
+}
+
+static int mtk_ahci_parse_property(struct ahci_uc_priv *hpriv,
+				   struct udevice *dev)
+{
+	struct mtk_ahci_priv *plat = dev_get_priv(dev);
+	const void *fdt = gd->fdt_blob;
+
+	/* enable SATA function if needed */
+	if (fdt_get_property(fdt, dev_of_offset(dev),
+			     "mediatek,phy-mode", NULL)) {
+		plat->mode = syscon_regmap_lookup_by_phandle(dev,
+						"mediatek,phy-mode");
+		if (IS_ERR(plat->mode)) {
+			dev_err(dev, "missing phy-mode phandle\n");
+			return PTR_ERR(plat->mode);
+		}
+		regmap_update_bits(plat->mode, SYS_CFG,
+				   SYS_CFG_SATA_MSK, SYS_CFG_SATA_EN);
+	}
+
+	ofnode_read_u32(dev->node, "ports-implemented", &hpriv->port_map);
+	return 0;
+}
+
+static int mtk_ahci_probe(struct udevice *dev)
+{
+	struct mtk_ahci_priv *priv = dev_get_priv(dev);
+	int ret;
+	struct phy phy;
+
+	ret = mtk_ahci_parse_property(&priv->ahci_priv, dev);
+	if (ret)
+		return ret;
+
+	ret = reset_get_bulk(dev, &priv->rst_bulk);
+	if (!ret) {
+		reset_assert_bulk(&priv->rst_bulk);
+		reset_deassert_bulk(&priv->rst_bulk);
+	} else {
+		dev_err(dev, "Failed to get reset: %d\n", ret);
+	}
+
+	ret = generic_phy_get_by_name(dev, "sata-phy", &phy);
+	if (ret) {
+		pr_err("can't get the phy from DT\n");
+		return ret;
+	}
+
+	ret = generic_phy_init(&phy);
+	if (ret) {
+		pr_err("unable to initialize the sata phy\n");
+		return ret;
+	}
+
+	ret = generic_phy_power_on(&phy);
+	if (ret) {
+		pr_err("unable to power on the sata phy\n");
+		return ret;
+	}
+
+	return ahci_probe_scsi(dev, (ulong)priv->base);
+}
+
+static const struct udevice_id mtk_ahci_ids[] = {
+	{ .compatible = "mediatek,mtk-ahci" },
+	{ }
+};
+
+U_BOOT_DRIVER(mtk_ahci) = {
+	.name	= "mtk_ahci",
+	.id	= UCLASS_AHCI,
+	.of_match = mtk_ahci_ids,
+	.bind	= mtk_ahci_bind,
+	.ofdata_to_platdata = mtk_ahci_ofdata_to_platdata,
+	.ops	= &scsi_ops,
+	.probe	= mtk_ahci_probe,
+	.priv_auto_alloc_size = sizeof(struct mtk_ahci_priv),
+};