1 files changed, 302 insertions, 0 deletions
diff --git a/drivers/acpi/sbshc.c b/drivers/acpi/sbshc.c
new file mode 100644
index 000000000..340e0b615
--- /dev/null
+++ b/drivers/acpi/sbshc.c
@@ -0,0 +1,302 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * SMBus driver for ACPI Embedded Controller (v0.1)
+ *
+ * Copyright (c) 2007 Alexey Starikovskiy
+ */
+
+#define pr_fmt(fmt) "ACPI: " fmt
+
+#include <linux/acpi.h>
+#include <linux/wait.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include "sbshc.h"
+
+#define ACPI_SMB_HC_CLASS	"smbus_host_ctl"
+#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;
+	bool done;
+};
+
+static int acpi_smbus_hc_add(struct acpi_device *device);
+static int acpi_smbus_hc_remove(struct acpi_device *device);
+
+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 int wait_transaction_complete(struct acpi_smb_hc *hc, int timeout)
+{
+	if (wait_event_timeout(hc->wait, hc->done, msecs_to_jiffies(timeout)))
+		return 0;
+	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) {
+		pr_err("host controller is not configured\n");
+		return ret;
+	}
+
+	mutex_lock(&hc->lock);
+	hc->done = false;
+	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);
+	acpi_os_wait_events_complete();
+	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 && status.fields.status == SMBUS_OK) {
+		hc->done = true;
+		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_NOTIFY_HANDLER,
+					acpi_smbus_callback, hc);
+	}
+	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)) {
+		pr_err("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(acpi_dev_parent(device));
+	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);
+	dev_info(&device->dev, "SBS HC: offset = 0x%0x, query_bit = 0x%0x\n",
+		 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)
+{
+	struct acpi_smb_hc *hc;
+
+	if (!device)
+		return -EINVAL;
+
+	hc = acpi_driver_data(device);
+	acpi_ec_remove_query_handler(hc->ec, hc->query_bit);
+	acpi_os_wait_events_complete();
+	kfree(hc);
+	device->driver_data = NULL;
+	return 0;
+}
+
+module_acpi_driver(acpi_smb_hc_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alexey Starikovskiy");
+MODULE_DESCRIPTION("ACPI SMBus HC driver");