5 files changed, 300 insertions, 1 deletions

diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index 1722f50f2473..80db3073aa84 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -2,8 +2,11 @@
 # Makefile for the i2c core.
 #
 
+i2ccore-y := i2c-core.o
+i2ccore-$(CONFIG_ACPI)          += i2c-acpi.o
+
 obj-$(CONFIG_I2C_BOARDINFO)     += i2c-boardinfo.o
-obj-$(CONFIG_I2C)               += i2c-core.o
+obj-$(CONFIG_I2C)               += i2ccore.o
 obj-$(CONFIG_I2C_SMBUS)         += i2c-smbus.o
 obj-$(CONFIG_I2C_CHARDEV)       += i2c-dev.o
 obj-$(CONFIG_I2C_MUX)           += i2c-mux.o
diff --git a/drivers/i2c/i2c-acpi.c b/drivers/i2c/i2c-acpi.c
new file mode 100644
index 000000000000..f7f4c89c09b3
--- /dev/null
+++ b/drivers/i2c/i2c-acpi.c
@@ -0,0 +1,273 @@
+/*
+ * I2C ACPI code
+ *
+ * Copyright (C) 2014 Intel Corp
+ *
+ * Author: Lan Tianyu <tianyu.lan@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ */
+#define pr_fmt(fmt) "I2C/ACPI : " fmt
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <linux/i2c.h>
+#include <linux/acpi.h>
+
+struct acpi_i2c_handler_data {
+        struct acpi_connection_info info;
+        struct i2c_adapter *adapter;
+};
+
+struct gsb_buffer {
+        u8      status;
+        u8      len;
+        union {
+                u16     wdata;
+                u8      bdata;
+                u8      data[0];
+        };
+} __packed;
+
+static int acpi_gsb_i2c_read_bytes(struct i2c_client *client,
+                u8 cmd, u8 *data, u8 data_len)
+{
+
+        struct i2c_msg msgs[2];
+        int ret;
+        u8 *buffer;
+
+        buffer = kzalloc(data_len, GFP_KERNEL);
+        if (!buffer)
+                return AE_NO_MEMORY;
+
+        msgs[0].addr = client->addr;
+        msgs[0].flags = client->flags;
+        msgs[0].len = 1;
+        msgs[0].buf = &cmd;
+
+        msgs[1].addr = client->addr;
+        msgs[1].flags = client->flags | I2C_M_RD;
+        msgs[1].len = data_len;
+        msgs[1].buf = buffer;
+
+        ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+        if (ret < 0)
+                dev_err(&client->adapter->dev, "i2c read failed\n");
+        else
+                memcpy(data, buffer, data_len);
+
+        kfree(buffer);
+        return ret;
+}
+
+static int acpi_gsb_i2c_write_bytes(struct i2c_client *client,
+                u8 cmd, u8 *data, u8 data_len)
+{
+
+        struct i2c_msg msgs[1];
+        u8 *buffer;
+        int ret = AE_OK;
+
+        buffer = kzalloc(data_len + 1, GFP_KERNEL);
+        if (!buffer)
+                return AE_NO_MEMORY;
+
+        buffer[0] = cmd;
+        memcpy(buffer + 1, data, data_len);
+
+        msgs[0].addr = client->addr;
+        msgs[0].flags = client->flags;
+        msgs[0].len = data_len + 1;
+        msgs[0].buf = buffer;
+
+        ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs));
+        if (ret < 0)
+                dev_err(&client->adapter->dev, "i2c write failed\n");
+
+        kfree(buffer);
+        return ret;
+}
+
+static acpi_status
+acpi_i2c_space_handler(u32 function, acpi_physical_address command,
+                        u32 bits, u64 *value64,
+                        void *handler_context, void *region_context)
+{
+        struct gsb_buffer *gsb = (struct gsb_buffer *)value64;
+        struct acpi_i2c_handler_data *data = handler_context;
+        struct acpi_connection_info *info = &data->info;
+        struct acpi_resource_i2c_serialbus *sb;
+        struct i2c_adapter *adapter = data->adapter;
+        struct i2c_client client;
+        struct acpi_resource *ares;
+        u32 accessor_type = function >> 16;
+        u8 action = function & ACPI_IO_MASK;
+        acpi_status ret = AE_OK;
+        int status;
+
+        ret = acpi_buffer_to_resource(info->connection, info->length, &ares);
+        if (ACPI_FAILURE(ret))
+                return ret;
+
+        if (!value64 || ares->type != ACPI_RESOURCE_TYPE_SERIAL_BUS) {
+                ret = AE_BAD_PARAMETER;
+                goto err;
+        }
+
+        sb = &ares->data.i2c_serial_bus;
+        if (sb->type != ACPI_RESOURCE_SERIAL_TYPE_I2C) {
+                ret = AE_BAD_PARAMETER;
+                goto err;
+        }
+
+        memset(&client, 0, sizeof(client));
+        client.adapter = adapter;
+        client.addr = sb->slave_address;
+        client.flags = 0;
+
+        if (sb->access_mode == ACPI_I2C_10BIT_MODE)
+                client.flags |= I2C_CLIENT_TEN;
+
+        switch (accessor_type) {
+        case ACPI_GSB_ACCESS_ATTRIB_SEND_RCV:
+                if (action == ACPI_READ) {
+                        status = i2c_smbus_read_byte(&client);
+                        if (status >= 0) {
+                                gsb->bdata = status;
+                                status = 0;
+                        }
+                } else {
+                        status = i2c_smbus_write_byte(&client, gsb->bdata);
+                }
+                break;
+
+        case ACPI_GSB_ACCESS_ATTRIB_BYTE:
+                if (action == ACPI_READ) {
+                        status = i2c_smbus_read_byte_data(&client, command);
+                        if (status >= 0) {
+                                gsb->bdata = status;
+                                status = 0;
+                        }
+                } else {
+                        status = i2c_smbus_write_byte_data(&client, command,
+                                        gsb->bdata);
+                }
+                break;
+
+        case ACPI_GSB_ACCESS_ATTRIB_WORD:
+                if (action == ACPI_READ) {
+                        status = i2c_smbus_read_word_data(&client, command);
+                        if (status >= 0) {
+                                gsb->wdata = status;
+                                status = 0;
+                        }
+                } else {
+                        status = i2c_smbus_write_word_data(&client, command,
+                                        gsb->wdata);
+                }
+                break;
+
+        case ACPI_GSB_ACCESS_ATTRIB_BLOCK:
+                if (action == ACPI_READ) {
+                        status = i2c_smbus_read_block_data(&client, command,
+                                        gsb->data);
+                        if (status >= 0) {
+                                gsb->len = status;
+                                status = 0;
+                        }
+                } else {
+                        status = i2c_smbus_write_block_data(&client, command,
+                                        gsb->len, gsb->data);
+                }
+                break;
+
+        case ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE:
+                if (action == ACPI_READ) {
+                        status = acpi_gsb_i2c_read_bytes(&client, command,
+                                        gsb->data, info->access_length);
+                        if (status > 0)
+                                status = 0;
+                } else {
+                        status = acpi_gsb_i2c_write_bytes(&client, command,
+                                        gsb->data, info->access_length);
+                }
+                break;
+
+        default:
+                pr_info("protocol(0x%02x) is not supported.\n", accessor_type);
+                ret = AE_BAD_PARAMETER;
+                goto err;
+        }
+
+        gsb->status = status;
+
+ err:
+        ACPI_FREE(ares);
+        return ret;
+}
+
+
+int acpi_i2c_install_space_handler(struct i2c_adapter *adapter)
+{
+        acpi_handle handle = ACPI_HANDLE(adapter->dev.parent);
+        struct acpi_i2c_handler_data *data;
+        acpi_status status;
+
+        if (!handle)
+                return -ENODEV;
+
+        data = kzalloc(sizeof(struct acpi_i2c_handler_data),
+                            GFP_KERNEL);
+        if (!data)
+                return -ENOMEM;
+
+        data->adapter = adapter;
+        status = acpi_bus_attach_private_data(handle, (void *)data);
+        if (ACPI_FAILURE(status)) {
+                kfree(data);
+                return -ENOMEM;
+        }
+
+        status = acpi_install_address_space_handler(handle,
+                                ACPI_ADR_SPACE_GSBUS,
+                                &acpi_i2c_space_handler,
+                                NULL,
+                                data);
+        if (ACPI_FAILURE(status)) {
+                dev_err(&adapter->dev, "Error installing i2c space handler\n");
+                acpi_bus_detach_private_data(handle);
+                kfree(data);
+                return -ENOMEM;
+        }
+
+        return 0;
+}
+
+void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter)
+{
+        acpi_handle handle = ACPI_HANDLE(adapter->dev.parent);
+        struct acpi_i2c_handler_data *data;
+        acpi_status status;
+
+        if (!handle)
+                return;
+
+        acpi_remove_address_space_handler(handle,
+                                ACPI_ADR_SPACE_GSBUS,
+                                &acpi_i2c_space_handler);
+
+        status = acpi_bus_get_private_data(handle, (void **)&data);
+        if (ACPI_SUCCESS(status))
+                kfree(data);
+
+        acpi_bus_detach_private_data(handle);
+}
diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c
index 7c7f4b856bad..e25cb84cb297 100644
--- a/drivers/i2c/i2c-core.c
+++ b/drivers/i2c/i2c-core.c
@@ -1293,6 +1293,7 @@ exit_recovery:
         /* create pre-declared device nodes */
         of_i2c_register_devices(adap);
         acpi_i2c_register_devices(adap);
+        acpi_i2c_install_space_handler(adap);
 
         if (adap->nr < __i2c_first_dynamic_bus_num)
                 i2c_scan_static_board_info(adap);
@@ -1466,6 +1467,7 @@ void i2c_del_adapter(struct i2c_adapter *adap)
                 return;
         }
 
+        acpi_i2c_remove_space_handler(adap);
         /* Tell drivers about this removal */
         mutex_lock(&core_lock);
         bus_for_each_drv(&i2c_bus_type, NULL, adap,
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 358c01b971db..40718e91e171 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -364,6 +364,17 @@ extern bool osc_sb_apei_support_acked;
 #define OSC_PCI_EXPRESS_CAPABILITY_CONTROL      0x00000010
 #define OSC_PCI_CONTROL_MASKS                   0x0000001f
 
+#define ACPI_GSB_ACCESS_ATTRIB_QUICK            0x00000002
+#define ACPI_GSB_ACCESS_ATTRIB_SEND_RCV         0x00000004
+#define ACPI_GSB_ACCESS_ATTRIB_BYTE             0x00000006
+#define ACPI_GSB_ACCESS_ATTRIB_WORD             0x00000008
+#define ACPI_GSB_ACCESS_ATTRIB_BLOCK            0x0000000A
+#define ACPI_GSB_ACCESS_ATTRIB_MULTIBYTE        0x0000000B
+#define ACPI_GSB_ACCESS_ATTRIB_WORD_CALL        0x0000000C
+#define ACPI_GSB_ACCESS_ATTRIB_BLOCK_CALL       0x0000000D
+#define ACPI_GSB_ACCESS_ATTRIB_RAW_BYTES        0x0000000E
+#define ACPI_GSB_ACCESS_ATTRIB_RAW_PROCESS      0x0000000F
+
 extern acpi_status acpi_pci_osc_control_set(acpi_handle handle,
                                              u32 *mask, u32 req);
 
diff --git a/include/linux/i2c.h b/include/linux/i2c.h
index b556e0ab946f..f7a939a2cb56 100644
--- a/include/linux/i2c.h
+++ b/include/linux/i2c.h
@@ -577,4 +577,14 @@ static inline struct i2c_adapter *of_find_i2c_adapter_by_node(struct device_node
 }
 #endif /* CONFIG_OF */
 
+#ifdef CONFIG_ACPI
+int acpi_i2c_install_space_handler(struct i2c_adapter *adapter);
+void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter);
+#else
+static inline void acpi_i2c_remove_space_handler(struct i2c_adapter *adapter)
+{ }
+static inline int acpi_i2c_install_space_handler(struct i2c_adapter *adapter)
+{ return 0; }
+#endif
+
 #endif /* _LINUX_I2C_H */