1 files changed, 327 insertions, 0 deletions
diff --git a/arch/x86/platform/intel/iosf_mbi.c b/arch/x86/platform/intel/iosf_mbi.c
new file mode 100644
index 000000000..edf2c54bf
--- /dev/null
+++ b/arch/x86/platform/intel/iosf_mbi.c
@@ -0,0 +1,327 @@
+/*
+ * IOSF-SB MailBox Interface Driver
+ * Copyright (c) 2013, Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ *
+ * The IOSF-SB is a fabric bus available on Atom based SOC's that uses a
+ * mailbox interface (MBI) to communicate with mutiple devices. This
+ * driver implements access to this interface for those platforms that can
+ * enumerate the device using PCI.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/pci.h>
+#include <linux/debugfs.h>
+#include <linux/capability.h>
+
+#include <asm/iosf_mbi.h>
+
+#define PCI_DEVICE_ID_BAYTRAIL		0x0F00
+#define PCI_DEVICE_ID_BRASWELL		0x2280
+#define PCI_DEVICE_ID_QUARK_X1000	0x0958
+#define PCI_DEVICE_ID_TANGIER		0x1170
+
+static struct pci_dev *mbi_pdev;
+static DEFINE_SPINLOCK(iosf_mbi_lock);
+
+static inline u32 iosf_mbi_form_mcr(u8 op, u8 port, u8 offset)
+{
+	return (op << 24) | (port << 16) | (offset << 8) | MBI_ENABLE;
+}
+
+static int iosf_mbi_pci_read_mdr(u32 mcrx, u32 mcr, u32 *mdr)
+{
+	int result;
+
+	if (!mbi_pdev)
+		return -ENODEV;
+
+	if (mcrx) {
+		result = pci_write_config_dword(mbi_pdev, MBI_MCRX_OFFSET,
+						mcrx);
+		if (result < 0)
+			goto fail_read;
+	}
+
+	result = pci_write_config_dword(mbi_pdev, MBI_MCR_OFFSET, mcr);
+	if (result < 0)
+		goto fail_read;
+
+	result = pci_read_config_dword(mbi_pdev, MBI_MDR_OFFSET, mdr);
+	if (result < 0)
+		goto fail_read;
+
+	return 0;
+
+fail_read:
+	dev_err(&mbi_pdev->dev, "PCI config access failed with %d\n", result);
+	return result;
+}
+
+static int iosf_mbi_pci_write_mdr(u32 mcrx, u32 mcr, u32 mdr)
+{
+	int result;
+
+	if (!mbi_pdev)
+		return -ENODEV;
+
+	result = pci_write_config_dword(mbi_pdev, MBI_MDR_OFFSET, mdr);
+	if (result < 0)
+		goto fail_write;
+
+	if (mcrx) {
+		result = pci_write_config_dword(mbi_pdev, MBI_MCRX_OFFSET,
+						mcrx);
+		if (result < 0)
+			goto fail_write;
+	}
+
+	result = pci_write_config_dword(mbi_pdev, MBI_MCR_OFFSET, mcr);
+	if (result < 0)
+		goto fail_write;
+
+	return 0;
+
+fail_write:
+	dev_err(&mbi_pdev->dev, "PCI config access failed with %d\n", result);
+	return result;
+}
+
+int iosf_mbi_read(u8 port, u8 opcode, u32 offset, u32 *mdr)
+{
+	u32 mcr, mcrx;
+	unsigned long flags;
+	int ret;
+
+	/* Access to the GFX unit is handled by GPU code */
+	if (port == BT_MBI_UNIT_GFX) {
+		WARN_ON(1);
+		return -EPERM;
+	}
+
+	mcr = iosf_mbi_form_mcr(opcode, port, offset & MBI_MASK_LO);
+	mcrx = offset & MBI_MASK_HI;
+
+	spin_lock_irqsave(&iosf_mbi_lock, flags);
+	ret = iosf_mbi_pci_read_mdr(mcrx, mcr, mdr);
+	spin_unlock_irqrestore(&iosf_mbi_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(iosf_mbi_read);
+
+int iosf_mbi_write(u8 port, u8 opcode, u32 offset, u32 mdr)
+{
+	u32 mcr, mcrx;
+	unsigned long flags;
+	int ret;
+
+	/* Access to the GFX unit is handled by GPU code */
+	if (port == BT_MBI_UNIT_GFX) {
+		WARN_ON(1);
+		return -EPERM;
+	}
+
+	mcr = iosf_mbi_form_mcr(opcode, port, offset & MBI_MASK_LO);
+	mcrx = offset & MBI_MASK_HI;
+
+	spin_lock_irqsave(&iosf_mbi_lock, flags);
+	ret = iosf_mbi_pci_write_mdr(mcrx, mcr, mdr);
+	spin_unlock_irqrestore(&iosf_mbi_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(iosf_mbi_write);
+
+int iosf_mbi_modify(u8 port, u8 opcode, u32 offset, u32 mdr, u32 mask)
+{
+	u32 mcr, mcrx;
+	u32 value;
+	unsigned long flags;
+	int ret;
+
+	/* Access to the GFX unit is handled by GPU code */
+	if (port == BT_MBI_UNIT_GFX) {
+		WARN_ON(1);
+		return -EPERM;
+	}
+
+	mcr = iosf_mbi_form_mcr(opcode, port, offset & MBI_MASK_LO);
+	mcrx = offset & MBI_MASK_HI;
+
+	spin_lock_irqsave(&iosf_mbi_lock, flags);
+
+	/* Read current mdr value */
+	ret = iosf_mbi_pci_read_mdr(mcrx, mcr & MBI_RD_MASK, &value);
+	if (ret < 0) {
+		spin_unlock_irqrestore(&iosf_mbi_lock, flags);
+		return ret;
+	}
+
+	/* Apply mask */
+	value &= ~mask;
+	mdr &= mask;
+	value |= mdr;
+
+	/* Write back */
+	ret = iosf_mbi_pci_write_mdr(mcrx, mcr | MBI_WR_MASK, value);
+
+	spin_unlock_irqrestore(&iosf_mbi_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(iosf_mbi_modify);
+
+bool iosf_mbi_available(void)
+{
+	/* Mbi isn't hot-pluggable. No remove routine is provided */
+	return mbi_pdev;
+}
+EXPORT_SYMBOL(iosf_mbi_available);
+
+#ifdef CONFIG_IOSF_MBI_DEBUG
+static u32	dbg_mdr;
+static u32	dbg_mcr;
+static u32	dbg_mcrx;
+
+static int mcr_get(void *data, u64 *val)
+{
+	*val = *(u32 *)data;
+	return 0;
+}
+
+static int mcr_set(void *data, u64 val)
+{
+	u8 command = ((u32)val & 0xFF000000) >> 24,
+	   port	   = ((u32)val & 0x00FF0000) >> 16,
+	   offset  = ((u32)val & 0x0000FF00) >> 8;
+	int err;
+
+	*(u32 *)data = val;
+
+	if (!capable(CAP_SYS_RAWIO))
+		return -EACCES;
+
+	if (command & 1u)
+		err = iosf_mbi_write(port,
+			       command,
+			       dbg_mcrx | offset,
+			       dbg_mdr);
+	else
+		err = iosf_mbi_read(port,
+			      command,
+			      dbg_mcrx | offset,
+			      &dbg_mdr);
+
+	return err;
+}
+DEFINE_SIMPLE_ATTRIBUTE(iosf_mcr_fops, mcr_get, mcr_set , "%llx\n");
+
+static struct dentry *iosf_dbg;
+
+static void iosf_sideband_debug_init(void)
+{
+	struct dentry *d;
+
+	iosf_dbg = debugfs_create_dir("iosf_sb", NULL);
+	if (IS_ERR_OR_NULL(iosf_dbg))
+		return;
+
+	/* mdr */
+	d = debugfs_create_x32("mdr", 0660, iosf_dbg, &dbg_mdr);
+	if (!d)
+		goto cleanup;
+
+	/* mcrx */
+	d = debugfs_create_x32("mcrx", 0660, iosf_dbg, &dbg_mcrx);
+	if (!d)
+		goto cleanup;
+
+	/* mcr - initiates mailbox tranaction */
+	d = debugfs_create_file("mcr", 0660, iosf_dbg, &dbg_mcr, &iosf_mcr_fops);
+	if (!d)
+		goto cleanup;
+
+	return;
+
+cleanup:
+	debugfs_remove_recursive(d);
+}
+
+static void iosf_debugfs_init(void)
+{
+	iosf_sideband_debug_init();
+}
+
+static void iosf_debugfs_remove(void)
+{
+	debugfs_remove_recursive(iosf_dbg);
+}
+#else
+static inline void iosf_debugfs_init(void) { }
+static inline void iosf_debugfs_remove(void) { }
+#endif /* CONFIG_IOSF_MBI_DEBUG */
+
+static int iosf_mbi_probe(struct pci_dev *pdev,
+			  const struct pci_device_id *unused)
+{
+	int ret;
+
+	ret = pci_enable_device(pdev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "error: could not enable device\n");
+		return ret;
+	}
+
+	mbi_pdev = pci_dev_get(pdev);
+	return 0;
+}
+
+static const struct pci_device_id iosf_mbi_pci_ids[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_BAYTRAIL) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_BRASWELL) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_QUARK_X1000) },
+	{ PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCI_DEVICE_ID_TANGIER) },
+	{ 0, },
+};
+MODULE_DEVICE_TABLE(pci, iosf_mbi_pci_ids);
+
+static struct pci_driver iosf_mbi_pci_driver = {
+	.name		= "iosf_mbi_pci",
+	.probe		= iosf_mbi_probe,
+	.id_table	= iosf_mbi_pci_ids,
+};
+
+static int __init iosf_mbi_init(void)
+{
+	iosf_debugfs_init();
+
+	return pci_register_driver(&iosf_mbi_pci_driver);
+}
+
+static void __exit iosf_mbi_exit(void)
+{
+	iosf_debugfs_remove();
+
+	pci_unregister_driver(&iosf_mbi_pci_driver);
+	pci_dev_put(mbi_pdev);
+	mbi_pdev = NULL;
+}
+
+module_init(iosf_mbi_init);
+module_exit(iosf_mbi_exit);
+
+MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>");
+MODULE_DESCRIPTION("IOSF Mailbox Interface accessor");
+MODULE_LICENSE("GPL v2");