| /* |
| * 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 DEFINE_MUTEX(iosf_mbi_punit_mutex); |
| static BLOCKING_NOTIFIER_HEAD(iosf_mbi_pmic_bus_access_notifier); |
| |
| 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); |
| |
| void iosf_mbi_punit_acquire(void) |
| { |
| mutex_lock(&iosf_mbi_punit_mutex); |
| } |
| EXPORT_SYMBOL(iosf_mbi_punit_acquire); |
| |
| void iosf_mbi_punit_release(void) |
| { |
| mutex_unlock(&iosf_mbi_punit_mutex); |
| } |
| EXPORT_SYMBOL(iosf_mbi_punit_release); |
| |
| int iosf_mbi_register_pmic_bus_access_notifier(struct notifier_block *nb) |
| { |
| int ret; |
| |
| /* Wait for the bus to go inactive before registering */ |
| mutex_lock(&iosf_mbi_punit_mutex); |
| ret = blocking_notifier_chain_register( |
| &iosf_mbi_pmic_bus_access_notifier, nb); |
| mutex_unlock(&iosf_mbi_punit_mutex); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(iosf_mbi_register_pmic_bus_access_notifier); |
| |
| int iosf_mbi_unregister_pmic_bus_access_notifier(struct notifier_block *nb) |
| { |
| int ret; |
| |
| /* Wait for the bus to go inactive before unregistering */ |
| mutex_lock(&iosf_mbi_punit_mutex); |
| ret = blocking_notifier_chain_unregister( |
| &iosf_mbi_pmic_bus_access_notifier, nb); |
| mutex_unlock(&iosf_mbi_punit_mutex); |
| |
| return ret; |
| } |
| EXPORT_SYMBOL(iosf_mbi_unregister_pmic_bus_access_notifier); |
| |
| int iosf_mbi_call_pmic_bus_access_notifier_chain(unsigned long val, void *v) |
| { |
| return blocking_notifier_call_chain( |
| &iosf_mbi_pmic_bus_access_notifier, val, v); |
| } |
| EXPORT_SYMBOL(iosf_mbi_call_pmic_bus_access_notifier_chain); |
| |
| #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"); |