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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /arch/x86/kernel/iosf_mbi.c
Initial import
Diffstat (limited to 'arch/x86/kernel/iosf_mbi.c')
-rw-r--r--arch/x86/kernel/iosf_mbi.c328
1 files changed, 328 insertions, 0 deletions
diff --git a/arch/x86/kernel/iosf_mbi.c b/arch/x86/kernel/iosf_mbi.c
new file mode 100644
index 000000000..82f8d02f0
--- /dev/null
+++ b/arch/x86/kernel/iosf_mbi.c
@@ -0,0 +1,328 @@
+/*
+ * 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
+
+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 struct pci_dev *mbi_pdev; /* one mbi device */
+
+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 (IS_ERR_OR_NULL(d))
+ goto cleanup;
+
+ /* mcrx */
+ debugfs_create_x32("mcrx", 0660, iosf_dbg, &dbg_mcrx);
+ if (IS_ERR_OR_NULL(d))
+ goto cleanup;
+
+ /* mcr - initiates mailbox tranaction */
+ debugfs_create_file("mcr", 0660, iosf_dbg, &dbg_mcr, &iosf_mcr_fops);
+ if (IS_ERR_OR_NULL(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) },
+ { 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);
+ if (mbi_pdev) {
+ 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");