ata: ahci_mvebu: new driver for Marvell Armada 380 AHCI interfaces

The Marvell Armada 380 SoC includes two AHCI compatible
interfaces. However, like all DMA-capable Marvell interface, they
require special handling to configure MBus windows. Therefore, this
commit adds a new ahci_mvebu driver, which relies on the
libahci_platform.c code recently introduced.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Signed-off-by: Tejun Heo <tj@kernel.org>

Documentation/devicetree/bindings/ata/ahci-platform.txt

@@ -9,6 +9,7 @@ Required properties:
   - "fsl,imx53-ahci"
   - "fsl,imx6q-ahci"
   - "ibm,476gtr-ahci"
+  - "marvell,armada-380-ahci"
   - "snps,dwc-ahci"
   - "snps,exynos5440-ahci"
   - "snps,spear-ahci"

drivers/ata/Kconfig

@@ -123,6 +123,15 @@ config AHCI_IMX
 
 	  If unsure, say N.
 
+config AHCI_MVEBU
+	tristate "Marvell EBU AHCI SATA support"
+	depends on ARCH_MVEBU
+	help
+	  This option enables support for the Marvebu EBU SoC's
+	  onboard AHCI SATA.
+
+	  If unsure, say N.
+
 config AHCI_SUNXI
 	tristate "Allwinner sunxi AHCI SATA support"
 	depends on ARCH_SUNXI

drivers/ata/Makefile

@@ -12,6 +12,7 @@ obj-$(CONFIG_SATA_DWC)		+= sata_dwc_460ex.o
 obj-$(CONFIG_SATA_HIGHBANK)	+= sata_highbank.o libahci.o
 obj-$(CONFIG_AHCI_DA850)	+= ahci_da850.o libahci.o libahci_platform.o
 obj-$(CONFIG_AHCI_IMX)		+= ahci_imx.o libahci.o libahci_platform.o
+obj-$(CONFIG_AHCI_MVEBU)	+= ahci_mvebu.o libahci.o libahci_platform.o
 obj-$(CONFIG_AHCI_SUNXI)	+= ahci_sunxi.o libahci.o libahci_platform.o
 obj-$(CONFIG_AHCI_ST)		+= ahci_st.o libahci.o libahci_platform.o
 obj-$(CONFIG_AHCI_XGENE)	+= ahci_xgene.o libahci.o libahci_platform.o

drivers/ata/ahci_mvebu.c

@@ -0,0 +1,127 @@
+/*
+ * AHCI glue platform driver for Marvell EBU SOCs
+ *
+ * Copyright (C) 2014 Marvell
+ *
+ * Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
+ * Marcin Wojtas <mw@semihalf.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2.  This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/ahci_platform.h>
+#include <linux/kernel.h>
+#include <linux/mbus.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include "ahci.h"
+
+#define AHCI_VENDOR_SPECIFIC_0_ADDR  0xa0
+#define AHCI_VENDOR_SPECIFIC_0_DATA  0xa4
+
+#define AHCI_WINDOW_CTRL(win)	(0x60 + ((win) << 4))
+#define AHCI_WINDOW_BASE(win)	(0x64 + ((win) << 4))
+#define AHCI_WINDOW_SIZE(win)	(0x68 + ((win) << 4))
+
+static void ahci_mvebu_mbus_config(struct ahci_host_priv *hpriv,
+				   const struct mbus_dram_target_info *dram)
+{
+	int i;
+
+	for (i = 0; i < 4; i++) {
+		writel(0, hpriv->mmio + AHCI_WINDOW_CTRL(i));
+		writel(0, hpriv->mmio + AHCI_WINDOW_BASE(i));
+		writel(0, hpriv->mmio + AHCI_WINDOW_SIZE(i));
+	}
+
+	for (i = 0; i < dram->num_cs; i++) {
+		const struct mbus_dram_window *cs = dram->cs + i;
+
+		writel((cs->mbus_attr << 8) |
+		       (dram->mbus_dram_target_id << 4) | 1,
+		       hpriv->mmio + AHCI_WINDOW_CTRL(i));
+		writel(cs->base, hpriv->mmio + AHCI_WINDOW_BASE(i));
+		writel(((cs->size - 1) & 0xffff0000),
+		       hpriv->mmio + AHCI_WINDOW_SIZE(i));
+	}
+}
+
+static void ahci_mvebu_regret_option(struct ahci_host_priv *hpriv)
+{
+	/*
+	 * Enable the regret bit to allow the SATA unit to regret a
+	 * request that didn't receive an acknowlegde and avoid a
+	 * deadlock
+	 */
+	writel(0x4, hpriv->mmio + AHCI_VENDOR_SPECIFIC_0_ADDR);
+	writel(0x80, hpriv->mmio + AHCI_VENDOR_SPECIFIC_0_DATA);
+}
+
+static const struct ata_port_info ahci_mvebu_port_info = {
+	.flags	   = AHCI_FLAG_COMMON,
+	.pio_mask  = ATA_PIO4,
+	.udma_mask = ATA_UDMA6,
+	.port_ops  = &ahci_platform_ops,
+};
+
+static int ahci_mvebu_probe(struct platform_device *pdev)
+{
+	struct ahci_host_priv *hpriv;
+	const struct mbus_dram_target_info *dram;
+	int rc;
+
+	hpriv = ahci_platform_get_resources(pdev);
+	if (IS_ERR(hpriv))
+		return PTR_ERR(hpriv);
+
+	rc = ahci_platform_enable_resources(hpriv);
+	if (rc)
+		return rc;
+
+	dram = mv_mbus_dram_info();
+	if (!dram)
+		return -ENODEV;
+
+	ahci_mvebu_mbus_config(hpriv, dram);
+	ahci_mvebu_regret_option(hpriv);
+
+	rc = ahci_platform_init_host(pdev, hpriv, &ahci_mvebu_port_info, 0, 0);
+	if (rc)
+		goto disable_resources;
+
+	return 0;
+
+disable_resources:
+	ahci_platform_disable_resources(hpriv);
+	return rc;
+}
+
+static const struct of_device_id ahci_mvebu_of_match[] = {
+	{ .compatible = "marvell,armada-380-ahci", },
+	{ },
+};
+MODULE_DEVICE_TABLE(of, ahci_mvebu_of_match);
+
+/*
+ * We currently don't provide power management related operations,
+ * since there is no suspend/resume support at the platform level for
+ * Armada 38x for the moment.
+ */
+static struct platform_driver ahci_mvebu_driver = {
+	.probe = ahci_mvebu_probe,
+	.remove = ata_platform_remove_one,
+	.driver = {
+		.name = "ahci-mvebu",
+		.owner = THIS_MODULE,
+		.of_match_table = ahci_mvebu_of_match,
+	},
+};
+module_platform_driver(ahci_mvebu_driver);
+
+MODULE_DESCRIPTION("Marvell EBU AHCI SATA driver");
+MODULE_AUTHOR("Thomas Petazzoni <thomas.petazzoni@free-electrons.com>, Marcin Wojtas <mw@semihalf.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:ahci_mvebu");