The Sideband Interface driver for Apollo Lake shares much similarity
with the existing iosf_mbi driver functionality wise, but was rewritten
for Apollo Lake due to incompatibility with the new registers.
Signed-off-by: Yong, Jonathan <jonathan.y...@intel.com>
---
arch/x86/Kconfig | 18 ++
arch/x86/platform/bxt/Makefile | 1 +
arch/x86/platform/bxt/sbi_apl.c | 399 ++++++++++++++++++++++++++++++++++
include/linux/platform_data/sbi_apl.h | 67 ++++++
4 files changed, 485 insertions(+)
create mode 100644 arch/x86/platform/bxt/Makefile
create mode 100644 arch/x86/platform/bxt/sbi_apl.c
create mode 100644 include/linux/platform_data/sbi_apl.h
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 226d569..8e3f6e2 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -563,6 +563,24 @@ config IOSF_MBI_DEBUG
If you don't require the option or are in doubt, say N.
+config X86_INTEL_SBI_APL
+ tristate "Intel SoC Sideband Interface for Apollo Lake"
+ depends on PCI
+ ---help---
+ This option enables sideband interface access for Intel Apollo Lake.
+ Like IOSF_MBI, the registers are used in lieu of MSR's.
+
+ You should say Y if you are running a kernel on Apollo Lake.
+
+config X86_INTEL_SBI_APL_DEBUG
+ bool "Enable Intel SoC SBI for Apollo Lake access in debugfs"
+ depends on X86_INTEL_SBI_APL && DEBUG_FS
+ ---help---
+ Select this option to expose the Sideband Interface through
+ debugfs.
+
+ You should say N if you do not plan to debug the SoC.
+
config X86_RDC321X
bool "RDC R-321x SoC"
depends on X86_32
diff --git a/arch/x86/platform/bxt/Makefile b/arch/x86/platform/bxt/Makefile
new file mode 100644
index 0000000..5990592
--- /dev/null
+++ b/arch/x86/platform/bxt/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_X86_INTEL_SBI_APL) += sbi_apl.o
diff --git a/arch/x86/platform/bxt/sbi_apl.c b/arch/x86/platform/bxt/sbi_apl.c
new file mode 100644
index 0000000..1974f5f
--- /dev/null
+++ b/arch/x86/platform/bxt/sbi_apl.c
@@ -0,0 +1,399 @@
+/*
+ * Sideband Interface driver for Apollo Lake
+ * Copyright (c) 2015, 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 Sideband Interface is an access mechanism to communicate with multiple
+ * devices on-board the SoC fabric over a PCI interface. This driver deals with
+ * the Apollo Lake SoC.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/mutex.h>
+#include <linux/pci.h>
+#include <linux/debugfs.h>
+#include <linux/capability.h>
+#include <linux/platform_device.h>
+
+#include <linux/platform_data/sbi_apl.h>
+
+#define DRV_NAME "sbi_apl"
+#define DRV_VERSION "1.0"
+
+static struct sbi_platform_data *plat_data;
+#define sbi_pdev_bus plat_data->bus
+#define sbi_pdev_slot plat_data->p2sb
+#define sbi_apl_lock plat_data->lock
+
+static u32 sbi_address(const struct sbi_apl_message *args)
+{
+ return (((u32)args->port_address) << 24 | args->register_offset);
+}
+
+static u16 sbi_status(const struct sbi_apl_message *args)
+{
+ return ((u16)args->opcode << 8) |
+ args->posted << 7 |
+ args->status << 1;
+}
+
+static u16 sbi_routing(const struct sbi_apl_message *args)
+{
+ return ((u16)args->byte_enable << 12) |
+ args->base_address_register << 8 |
+ args->function_id;
+}
+
+/* returns 0 on OK wait */
+static int sbi_do_wait(struct pci_bus *sbi_pdev, unsigned int devfn, u16 *word)
+{
+ int ret;
+ unsigned int timeout = 0x0FFFFFFF; /*2^28-1*/
+
+ do {
+ ret = pci_bus_read_config_word(
+ sbi_pdev,
+ devfn,
+ SBI_STAT_OFFSET,
+ word);
+ if (ret)
+ return ret;
+ if (*word == (u16) -1) {
+ pr_err("sbi_do_wait busy wait failed, P2SB read not
allowed?");
+ return 1;
+ }
+ timeout--;
+ } while (timeout && (*word & SBI_STAT_BUSY_MASK));
+ /* fail if time-out occurs */
+ return timeout ? 0 : 1;
+}
+
+static int sbi_do_write(struct pci_bus *sbi_pdev, unsigned int devfn,
+ struct sbi_apl_message *args)
+{
+ int ret = 0;
+ u16 word;
+
+ if (!sbi_pdev)
+ return -ENODEV;
+ if (!capable(CAP_SYS_RAWIO))
+ return -EACCES;
+ /* Is it busy? */
+ if (sbi_do_wait(sbi_pdev, devfn, &word)) {
+ pr_err(DRV_NAME " device has busy bit set %hx!\n", word);
+ ret = -EAGAIN;
+ goto err;
+ };
+ ret = pci_bus_write_config_dword(sbi_pdev, devfn,
+ SBI_ADDR_OFFSET, sbi_address(args));
+ if (ret)
+ goto err;
+ ret = pci_bus_write_config_dword(sbi_pdev, devfn,
+ SBI_DATA_OFFSET, args->data);
+ if (ret)
+ goto err;
+ ret = pci_bus_write_config_word(sbi_pdev, devfn,
+ SBI_ROUT_OFFSET, sbi_routing(args));
+ if (ret)
+ goto err;
+ ret = pci_bus_write_config_dword(sbi_pdev, devfn,
+ SBI_EADD_OFFSET, args->extended_register_address);
+ if (ret)
+ goto err;
+ ret = pci_bus_write_config_word(sbi_pdev, devfn,
+ SBI_STAT_OFFSET, sbi_status(args) | SBI_STAT_BUSY_MASK);
+ if (ret)
+ goto err;
+
+ /* Wait for busy loop */
+ if (sbi_do_wait(sbi_pdev, devfn, &word)) {
+ pr_err(DRV_NAME " device is not responding %hx!\n", word);
+ ret = -EBUSY;
+ goto err;
+ };
+ args->opcode = (word & 0xff00) >> 8;
+ args->posted = (word & 0x0080) >> 7;
+ args->status = (word & 0x0006) >> 1;
+
+ ret = pci_bus_read_config_dword(sbi_pdev, devfn,
+ SBI_DATA_OFFSET, &args->data);
+ if (ret)
+ goto err;
+ pr_debug(DRV_NAME" read commit got %04x\n", args->data);
+ return 0;
+err:
+ pr_err(DRV_NAME " PCI config access failed with %d\n", ret);
+ return ret;
+}
+
+static int sbi_validate(const struct sbi_apl_message *args)
+{
+ if (args->posted > 0x01 ||
+ args->status > 0x03 ||
+ args->byte_enable > 0x0f ||
+ args->base_address_register > 0x07)
+ return -EINVAL;
+ return 0;
+}
+
+/* hide/unhide P2SB PCI device
+ * hide = 1 device will be hidden
+ * hide = 0 device will be visible
+ */
+static void sbi_hide(struct pci_bus *bus, unsigned int devfn, int hide)
+{
+ pci_bus_write_config_byte(bus, devfn, 0xe1, hide);
+}
+
+/* we don't hide anything if it is somehow not hidden to begin with */
+static int sbi_ishidden(struct pci_bus *bus, unsigned int devfn)
+{
+ u8 ret;
+
+ pci_bus_read_config_byte(bus, devfn, 0xe1, &ret);
+ return (ret) ? 1 : 0;
+}
+
+int sbi_apl_commit(struct sbi_apl_message *args)
+{
+ int ret;
+ struct pci_bus *sbi_pdev;
+
+ ret = sbi_validate(args);
+ if (ret)
+ return ret;
+
+ sbi_pdev = pci_find_bus(0, sbi_pdev_bus);
+ if (!sbi_pdev)
+ return -ENODEV;
+ mutex_lock(sbi_apl_lock);
+ sbi_hide(sbi_pdev, sbi_pdev_slot, 0);
+ ret = sbi_do_write(sbi_pdev, sbi_pdev_slot, args);
+ sbi_hide(sbi_pdev, sbi_pdev_slot, 1);
+ mutex_unlock(sbi_apl_lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(sbi_apl_commit);
+#ifdef CONFIG_X86_INTEL_SBI_APL_DEBUG
+static struct dentry *sbi_dbg;
+static struct sbi_apl_message debug_args;
+
+static void sbi_dbg_cleanup(void)
+{
+ debugfs_remove_recursive(sbi_dbg);
+ sbi_dbg = NULL;
+}
+
+static int dbg_posted_set(void *data, u64 val)
+{
+ *(u8 *)data = !!val;
+ return 0;
+}
+
+static int dbg_status_set(void *data, u64 val)
+{
+ *(u8 *)data = val & SBI_STAT_STATUS_MASK;
+ return 0;
+}
+
+static int dbg_byte_enable_set(void *data, u64 val)
+{
+ *(u8 *)data = val & SBI_STAT_BYTE_ENABLE_MASK;
+ return 0;
+}
+
+static int dbg_base_address_register_fops_set(void *data, u64 val)
+{
+ *(u8 *)data = val & SBI_STAT_BAR_MASK;
+ return 0;
+}
+
+static int dbg_commit_set(void *data, u64 val)
+{
+ return sbi_apl_commit(&debug_args);
+}
+
+static int dbg_u8_get(void *data, u64 *val)
+{
+ *val = *(u8 *)data;
+ return 0;
+}
+
+DEFINE_SIMPLE_ATTRIBUTE(posted_fops, dbg_u8_get, dbg_posted_set, "0x%01llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(status_fops, dbg_u8_get, dbg_status_set, "0x%01llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(byte_enable_fops, dbg_u8_get, dbg_byte_enable_set,
+ "0x%01llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(base_address_register_fops, dbg_u8_get,
+ dbg_base_address_register_fops_set, "0x%01llx\n");
+DEFINE_SIMPLE_ATTRIBUTE(commit_fops, NULL, dbg_commit_set, "0x%01llx\n");
+
+static void sbi_dbg_setup(void)
+{
+ struct dentry *d;
+
+ if (!IS_ERR_OR_NULL(sbi_dbg))
+ return;
+ memset(&debug_args, 0, sizeof(debug_args));
+ sbi_dbg = debugfs_create_dir("sbi_apl", NULL);
+ if (IS_ERR_OR_NULL(sbi_dbg))
+ return;
+
+ /* port_address */
+ d = debugfs_create_x8("port_address", 0660, sbi_dbg,
+ &debug_args.port_address);
+ if (!d)
+ goto cleanup;
+
+ /* register_offset */
+ d = debugfs_create_x16("register_offset", 0660, sbi_dbg,
+ &debug_args.register_offset);
+ if (!d)
+ goto cleanup;
+
+ /* opcode */
+ d = debugfs_create_x8("opcode", 0660, sbi_dbg, &debug_args.opcode);
+ if (!d)
+ goto cleanup;
+
+ /* data */
+ d = debugfs_create_x32("data", 0660, sbi_dbg, &debug_args.data);
+ if (!d)
+ goto cleanup;
+
+ /* posted */
+ d = debugfs_create_file("posted", 0660, sbi_dbg, &debug_args.posted,
+ &posted_fops);
+ if (!d)
+ goto cleanup;
+
+ /* status */
+ d = debugfs_create_file("status", 0660, sbi_dbg, &debug_args.status,
+ &status_fops);
+ if (!d)
+ goto cleanup;
+
+ /* byte_enable */
+ d = debugfs_create_file("byte_enable", 0660, sbi_dbg,
+ &debug_args.byte_enable, &byte_enable_fops);
+ if (!d)
+ goto cleanup;
+
+ /* base_address_register */
+ d = debugfs_create_file("base_address_register",
+ 0660, sbi_dbg, &debug_args.base_address_register,
+ &base_address_register_fops);
+ if (!d)
+ goto cleanup;
+
+ /* function_id */
+ d = debugfs_create_x8("function_id", 0660, sbi_dbg,
+ &debug_args.function_id);
+ if (!d)
+ goto cleanup;
+
+ /* extended_register_address */
+ d = debugfs_create_x32("extended_register_address", 0660, sbi_dbg,
+ &debug_args.extended_register_address);
+ if (!d)
+ goto cleanup;
+
+ /* commit - initiate write to registers */
+ d = debugfs_create_file("commit", 0220, sbi_dbg, NULL, &commit_fops);
+ if (!d)
+ goto cleanup;
+
+ return;
+
+cleanup:
+ sbi_dbg_cleanup();
+}
+
+#else
+static void sbi_dbg_setup(void)
+{
+}
+static void sbi_dbg_cleanup(void)
+{
+}
+#endif /* CONFIG_X86_INTEL_SBI_DEBUG */
+
+static int sbi_apl_plat_probe(struct platform_device *dev)
+{
+ struct pci_bus *bus = NULL;
+ struct sbi_platform_data *pdata;
+ u32 id;
+ int ret;
+
+ if (!dev)
+ return -ENODEV;
+
+ pdata = dev_get_platdata(&dev->dev);
+
+ pr_info("%s starting, bus %x, device %01x.%x", pdata->name, pdata->bus,
+ PCI_SLOT(pdata->p2sb), PCI_FUNC(pdata->p2sb));
+ bus = pci_find_bus(0, pdata->bus);
+ if (!bus) {
+ pr_warn("Cannot get P2SB bus!");
+ return -ENODEV;
+ }
+ mutex_lock(pdata->lock);
+ sbi_hide(bus, pdata->p2sb, 0);
+
+ if (sbi_ishidden(bus, pdata->p2sb)) {
+ pci_bus_read_config_dword(bus, pdata->p2sb, 0x00, &id);
+ if (id != (u32)-1) {
+ pr_warn("P2SB (0x%08x) might be there but disabled",
+ id);
+ } else {
+ pr_err("Cannot unhideP2SB, is it really there?");
+ ret = -ENODEV;
+ goto out;
+ }
+ }
+ sbi_hide(bus, pdata->p2sb, 1);
+ mutex_unlock(pdata->lock);
+ plat_data = pdata;
+ sbi_dbg_setup();
+ return 0;
+
+out:
+ mutex_unlock(pdata->lock);
+ return ret;
+}
+
+static struct platform_driver sbi_plat_driver = {
+ .probe = sbi_apl_plat_probe,
+ .driver = {
+ .name = DRV_NAME,
+ },
+};
+
+static void __exit sbi_apl_exit(void)
+{
+ sbi_dbg_cleanup();
+ platform_driver_unregister(&sbi_plat_driver);
+}
+
+static int __init sbi_apl_init(void)
+{
+ pr_info("Apollo Lake Sideband Interface loading");
+ return platform_driver_register(&sbi_plat_driver);
+}
+
+MODULE_DESCRIPTION("Apollo Lake Sideband Interface");
+MODULE_VERSION(DRV_VERSION);
+module_init(sbi_apl_init);
+module_exit(sbi_apl_exit);
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRV_NAME);
diff --git a/include/linux/platform_data/sbi_apl.h
b/include/linux/platform_data/sbi_apl.h
new file mode 100644
index 0000000..7cd6889
--- /dev/null
+++ b/include/linux/platform_data/sbi_apl.h
@@ -0,0 +1,67 @@
+#ifndef SBI_APL_H
+#define SBI_APL_H
+
+#define SBI_ADDR_OFFSET 0xD0
+#define SBI_DATA_OFFSET 0xD4
+#define SBI_STAT_OFFSET 0xD8
+#define SBI_ROUT_OFFSET 0xDA
+#define SBI_EADD_OFFSET 0xDC
+
+/* Status register */
+#define SBI_STAT_POSTED_MASK 0x01
+#define SBI_STAT_STATUS_MASK 0x03
+#define SBI_STAT_BYTE_ENABLE_MASK 0x0F
+#define SBI_STAT_BAR_MASK 0x07
+#define SBI_STAT_BUSY_MASK 0x01
+
+#define SBI_APL_SET_POSTED(msg, val) \
+ ((msg)->posted = ((val) & SBI_STAT_POSTED_MASK))
+#define SBI_APL_SET_STATUS(msg, val) \
+ ((msg)->status = ((val) & SBI_STAT_STATUS_MASK))
+#define SBI_APL_SET_BYTE_ENABLE(msg, val) \
+ ((msg)->byte_enable = ((val) & SBI_STAT_BYTE_ENABLE_MASK))
+#define SBI_APL_SET_BAR(msg, val) \
+ ((msg)->base_address_register = ((val) & SBI_STAT_BAR_MASK))
+
+#define SBI_APL_SET(msg, port, reg, data, opcode, \
+ posted, status, be, bar, funct, eaddr) \
+ do { \
+ (msg)->port_address = (port); \
+ (msg)->register_offset = (reg); \
+ (msg)->data = (data); \
+ SBI_APL_SET_POSTED(msg, opcode); \
+ SBI_STAT_STATUS_MASK(msg, status); \
+ SBI_APL_SET_BYTE_ENABLE(msg, be); \
+ SBI_APL_SET_BAR(msg, bar); \
+ (msg)->function_id = (funct); \
+ (msg)->extended_register_address = (eaddr); \
+ } while (0)
+
+struct sbi_platform_data {
+ const char *name;
+ unsigned int version;
+ unsigned int bus;
+ unsigned int p2sb;
+ struct mutex *lock;
+};
+
+struct sbi_apl_message {
+ u8 port_address;
+ u16 register_offset;
+ u32 data;
+ u8 opcode;
+ /* 1-bit */
+ u8 posted;
+ /* 2-bit */
+ u8 status;
+ /* 4-bit */
+ u8 byte_enable;
+ /* 3-bit */
+ u8 base_address_register;
+ u8 function_id;
+ u32 extended_register_address;
+};
+
+int sbi_apl_commit(struct sbi_apl_message *args);
+
+#endif
--
2.7.3
--
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