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-rw-r--r--drivers/acpi/sbshc.c330
1 files changed, 330 insertions, 0 deletions
diff --git a/drivers/acpi/sbshc.c b/drivers/acpi/sbshc.c
new file mode 100644
index 0000000..e53e590
--- /dev/null
+++ b/drivers/acpi/sbshc.c
@@ -0,0 +1,330 @@
+/*
+ * SMBus driver for ACPI Embedded Controller (v0.1)
+ *
+ * Copyright (c) 2007 Alexey Starikovskiy
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation version 2.
+ */
+
+#include <acpi/acpi_bus.h>
+#include <acpi/acpi_drivers.h>
+#include <acpi/actypes.h>
+#include <linux/wait.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include "sbshc.h"
+
+#define ACPI_SMB_HC_CLASS "smbus_host_controller"
+#define ACPI_SMB_HC_DEVICE_NAME "ACPI SMBus HC"
+
+struct acpi_smb_hc {
+ struct acpi_ec *ec;
+ struct mutex lock;
+ wait_queue_head_t wait;
+ u8 offset;
+ u8 query_bit;
+ smbus_alarm_callback callback;
+ void *context;
+};
+
+static int acpi_smbus_hc_add(struct acpi_device *device);
+static int acpi_smbus_hc_remove(struct acpi_device *device, int type);
+
+static const struct acpi_device_id sbs_device_ids[] = {
+ {"ACPI0001", 0},
+ {"ACPI0005", 0},
+ {"", 0},
+};
+
+MODULE_DEVICE_TABLE(acpi, sbs_device_ids);
+
+static struct acpi_driver acpi_smb_hc_driver = {
+ .name = "smbus_hc",
+ .class = ACPI_SMB_HC_CLASS,
+ .ids = sbs_device_ids,
+ .ops = {
+ .add = acpi_smbus_hc_add,
+ .remove = acpi_smbus_hc_remove,
+ },
+};
+
+union acpi_smb_status {
+ u8 raw;
+ struct {
+ u8 status:5;
+ u8 reserved:1;
+ u8 alarm:1;
+ u8 done:1;
+ } fields;
+};
+
+enum acpi_smb_status_codes {
+ SMBUS_OK = 0,
+ SMBUS_UNKNOWN_FAILURE = 0x07,
+ SMBUS_DEVICE_ADDRESS_NACK = 0x10,
+ SMBUS_DEVICE_ERROR = 0x11,
+ SMBUS_DEVICE_COMMAND_ACCESS_DENIED = 0x12,
+ SMBUS_UNKNOWN_ERROR = 0x13,
+ SMBUS_DEVICE_ACCESS_DENIED = 0x17,
+ SMBUS_TIMEOUT = 0x18,
+ SMBUS_HOST_UNSUPPORTED_PROTOCOL = 0x19,
+ SMBUS_BUSY = 0x1a,
+ SMBUS_PEC_ERROR = 0x1f,
+};
+
+enum acpi_smb_offset {
+ ACPI_SMB_PROTOCOL = 0, /* protocol, PEC */
+ ACPI_SMB_STATUS = 1, /* status */
+ ACPI_SMB_ADDRESS = 2, /* address */
+ ACPI_SMB_COMMAND = 3, /* command */
+ ACPI_SMB_DATA = 4, /* 32 data registers */
+ ACPI_SMB_BLOCK_COUNT = 0x24, /* number of data bytes */
+ ACPI_SMB_ALARM_ADDRESS = 0x25, /* alarm address */
+ ACPI_SMB_ALARM_DATA = 0x26, /* 2 bytes alarm data */
+};
+
+static inline int smb_hc_read(struct acpi_smb_hc *hc, u8 address, u8 *data)
+{
+ return ec_read(hc->offset + address, data);
+}
+
+static inline int smb_hc_write(struct acpi_smb_hc *hc, u8 address, u8 data)
+{
+ return ec_write(hc->offset + address, data);
+}
+
+static inline int smb_check_done(struct acpi_smb_hc *hc)
+{
+ union acpi_smb_status status = {.raw = 0};
+ smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw);
+ return status.fields.done && (status.fields.status == SMBUS_OK);
+}
+
+static int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout)
+{
+ if (wait_event_timeout(hc->wait, smb_check_done(hc),
+ msecs_to_jiffies(timeout)))
+ return 0;
+ /*
+ * After the timeout happens, OS will try to check the status of SMbus.
+ * If the status is what OS expected, it will be regarded as the bogus
+ * timeout.
+ */
+ if (smb_check_done(hc))
+ return 0;
+ else
+ return -ETIME;
+}
+
+static int acpi_smbus_transaction(struct acpi_smb_hc *hc, u8 protocol,
+ u8 address, u8 command, u8 *data, u8 length)
+{
+ int ret = -EFAULT, i;
+ u8 temp, sz = 0;
+
+ if (!hc) {
+ printk(KERN_ERR PREFIX "host controller is not configured\n");
+ return ret;
+ }
+
+ mutex_lock(&hc->lock);
+ if (smb_hc_read(hc, ACPI_SMB_PROTOCOL, &temp))
+ goto end;
+ if (temp) {
+ ret = -EBUSY;
+ goto end;
+ }
+ smb_hc_write(hc, ACPI_SMB_COMMAND, command);
+ if (!(protocol & 0x01)) {
+ smb_hc_write(hc, ACPI_SMB_BLOCK_COUNT, length);
+ for (i = 0; i < length; ++i)
+ smb_hc_write(hc, ACPI_SMB_DATA + i, data[i]);
+ }
+ smb_hc_write(hc, ACPI_SMB_ADDRESS, address << 1);
+ smb_hc_write(hc, ACPI_SMB_PROTOCOL, protocol);
+ /*
+ * Wait for completion. Save the status code, data size,
+ * and data into the return package (if required by the protocol).
+ */
+ ret = wait_transaction_complete(hc, 1000);
+ if (ret || !(protocol & 0x01))
+ goto end;
+ switch (protocol) {
+ case SMBUS_RECEIVE_BYTE:
+ case SMBUS_READ_BYTE:
+ sz = 1;
+ break;
+ case SMBUS_READ_WORD:
+ sz = 2;
+ break;
+ case SMBUS_READ_BLOCK:
+ if (smb_hc_read(hc, ACPI_SMB_BLOCK_COUNT, &sz)) {
+ ret = -EFAULT;
+ goto end;
+ }
+ sz &= 0x1f;
+ break;
+ }
+ for (i = 0; i < sz; ++i)
+ smb_hc_read(hc, ACPI_SMB_DATA + i, &data[i]);
+ end:
+ mutex_unlock(&hc->lock);
+ return ret;
+}
+
+int acpi_smbus_read(struct acpi_smb_hc *hc, u8 protocol, u8 address,
+ u8 command, u8 *data)
+{
+ return acpi_smbus_transaction(hc, protocol, address, command, data, 0);
+}
+
+EXPORT_SYMBOL_GPL(acpi_smbus_read);
+
+int acpi_smbus_write(struct acpi_smb_hc *hc, u8 protocol, u8 address,
+ u8 command, u8 *data, u8 length)
+{
+ return acpi_smbus_transaction(hc, protocol, address, command, data, length);
+}
+
+EXPORT_SYMBOL_GPL(acpi_smbus_write);
+
+int acpi_smbus_register_callback(struct acpi_smb_hc *hc,
+ smbus_alarm_callback callback, void *context)
+{
+ mutex_lock(&hc->lock);
+ hc->callback = callback;
+ hc->context = context;
+ mutex_unlock(&hc->lock);
+ return 0;
+}
+
+EXPORT_SYMBOL_GPL(acpi_smbus_register_callback);
+
+int acpi_smbus_unregister_callback(struct acpi_smb_hc *hc)
+{
+ mutex_lock(&hc->lock);
+ hc->callback = NULL;
+ hc->context = NULL;
+ mutex_unlock(&hc->lock);
+ return 0;
+}
+
+EXPORT_SYMBOL_GPL(acpi_smbus_unregister_callback);
+
+static inline void acpi_smbus_callback(void *context)
+{
+ struct acpi_smb_hc *hc = context;
+ if (hc->callback)
+ hc->callback(hc->context);
+}
+
+static int smbus_alarm(void *context)
+{
+ struct acpi_smb_hc *hc = context;
+ union acpi_smb_status status;
+ u8 address;
+ if (smb_hc_read(hc, ACPI_SMB_STATUS, &status.raw))
+ return 0;
+ /* Check if it is only a completion notify */
+ if (status.fields.done)
+ wake_up(&hc->wait);
+ if (!status.fields.alarm)
+ return 0;
+ mutex_lock(&hc->lock);
+ smb_hc_read(hc, ACPI_SMB_ALARM_ADDRESS, &address);
+ status.fields.alarm = 0;
+ smb_hc_write(hc, ACPI_SMB_STATUS, status.raw);
+ /* We are only interested in events coming from known devices */
+ switch (address >> 1) {
+ case ACPI_SBS_CHARGER:
+ case ACPI_SBS_MANAGER:
+ case ACPI_SBS_BATTERY:
+ acpi_os_execute(OSL_GPE_HANDLER,
+ acpi_smbus_callback, hc);
+ default:;
+ }
+ mutex_unlock(&hc->lock);
+ return 0;
+}
+
+typedef int (*acpi_ec_query_func) (void *data);
+
+extern int acpi_ec_add_query_handler(struct acpi_ec *ec, u8 query_bit,
+ acpi_handle handle, acpi_ec_query_func func,
+ void *data);
+
+static int acpi_smbus_hc_add(struct acpi_device *device)
+{
+ int status;
+ unsigned long long val;
+ struct acpi_smb_hc *hc;
+
+ if (!device)
+ return -EINVAL;
+
+ status = acpi_evaluate_integer(device->handle, "_EC", NULL, &val);
+ if (ACPI_FAILURE(status)) {
+ printk(KERN_ERR PREFIX "error obtaining _EC.\n");
+ return -EIO;
+ }
+
+ strcpy(acpi_device_name(device), ACPI_SMB_HC_DEVICE_NAME);
+ strcpy(acpi_device_class(device), ACPI_SMB_HC_CLASS);
+
+ hc = kzalloc(sizeof(struct acpi_smb_hc), GFP_KERNEL);
+ if (!hc)
+ return -ENOMEM;
+ mutex_init(&hc->lock);
+ init_waitqueue_head(&hc->wait);
+
+ hc->ec = acpi_driver_data(device->parent);
+ hc->offset = (val >> 8) & 0xff;
+ hc->query_bit = val & 0xff;
+ device->driver_data = hc;
+
+ acpi_ec_add_query_handler(hc->ec, hc->query_bit, NULL, smbus_alarm, hc);
+ printk(KERN_INFO PREFIX "SBS HC: EC = 0x%p, offset = 0x%0x, query_bit = 0x%0x\n",
+ hc->ec, hc->offset, hc->query_bit);
+
+ return 0;
+}
+
+extern void acpi_ec_remove_query_handler(struct acpi_ec *ec, u8 query_bit);
+
+static int acpi_smbus_hc_remove(struct acpi_device *device, int type)
+{
+ struct acpi_smb_hc *hc;
+
+ if (!device)
+ return -EINVAL;
+
+ hc = acpi_driver_data(device);
+ acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
+ kfree(hc);
+ device->driver_data = NULL;
+ return 0;
+}
+
+static int __init acpi_smb_hc_init(void)
+{
+ int result;
+
+ result = acpi_bus_register_driver(&acpi_smb_hc_driver);
+ if (result < 0)
+ return -ENODEV;
+ return 0;
+}
+
+static void __exit acpi_smb_hc_exit(void)
+{
+ acpi_bus_unregister_driver(&acpi_smb_hc_driver);
+}
+
+module_init(acpi_smb_hc_init);
+module_exit(acpi_smb_hc_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alexey Starikovskiy");
+MODULE_DESCRIPTION("ACPI SMBus HC driver");
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