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>

3 files changed, 137 insertions, 0 deletions

diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 20e03a7eb8b4..58d04cb31cec 100644
--- a/drivers/ata/Kconfig
+++ b/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
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index 44c8016e565c..5a02aeecef5b 100644
--- a/drivers/ata/Makefile
+++ b/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
diff --git a/drivers/ata/ahci_mvebu.c b/drivers/ata/ahci_mvebu.c
new file mode 100644
index 000000000000..1df8630c6b65
--- /dev/null
+++ b/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");