ACPI: consolidate functions in acpi ec driver

Unify the following functions:

    acpi_ec_poll_read()
    acpi_ec_poll_write()
    acpi_ec_poll_query()
    acpi_ec_intr_read()
    acpi_ec_intr_write()
    acpi_ec_intr_query()

into:

    acpi_ec_poll_transaction()
    acpi_ec_intr_transaction()

These new functions take as arguments an ACPI EC command, a few bytes
to write to the EC data register and a buffer for a few bytes to read
from the EC data register. The old _read(), _write(), _query() are
just special cases of these functions.

Then unified the code in acpi_ec_poll_transaction() and
acpi_ec_intr_transaction() a little more. Both functions are now just
wrappers around the new acpi_ec_transaction_unlocked() function. The
latter contains the EC access logic, the two original
function now just do their special way of locking and call the the
new function for the actual work.

This saves a lot of very similar code. The primary reason for doing
this, however, is that my driver for MSI 270 laptops needs to issue
some non-standard EC commands in a safe way. Due to this I added a new
exported function similar to ec_write()/ec_write() which is called
ec_transaction() and is essentially just a wrapper around
acpi_ec_{poll,intr}_transaction().

Signed-off-by: Lennart Poettering <mzxreary@0pointer.de>
Acked-by: Luming Yu <luming.yu@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Len Brown <len.brown@intel.com>

2 files changed, 98 insertions, 230 deletions

diff --git a/drivers/acpi/ec.c b/drivers/acpi/ec.c
index e5d796362854..a0dcbad97c45 100644
--- a/drivers/acpi/ec.c
+++ b/drivers/acpi/ec.c
@@ -122,12 +122,12 @@ union acpi_ec {
 
 static int acpi_ec_poll_wait(union acpi_ec *ec, u8 event);
 static int acpi_ec_intr_wait(union acpi_ec *ec, unsigned int event);
-static int acpi_ec_poll_read(union acpi_ec *ec, u8 address, u32 * data);
-static int acpi_ec_intr_read(union acpi_ec *ec, u8 address, u32 * data);
-static int acpi_ec_poll_write(union acpi_ec *ec, u8 address, u8 data);
-static int acpi_ec_intr_write(union acpi_ec *ec, u8 address, u8 data);
-static int acpi_ec_poll_query(union acpi_ec *ec, u32 * data);
-static int acpi_ec_intr_query(union acpi_ec *ec, u32 * data);
+static int acpi_ec_poll_transaction(union acpi_ec *ec, u8 command,
+                                    const u8 *wdata, unsigned wdata_len,
+                                    u8 *rdata, unsigned rdata_len);
+static int acpi_ec_intr_transaction(union acpi_ec *ec, u8 command,
+                                    const u8 *wdata, unsigned wdata_len,
+                                    u8 *rdata, unsigned rdata_len);
 static void acpi_ec_gpe_poll_query(void *ec_cxt);
 static void acpi_ec_gpe_intr_query(void *ec_cxt);
 static u32 acpi_ec_gpe_poll_handler(void *data);
@@ -302,110 +302,95 @@ end:
 }
 #endif /* ACPI_FUTURE_USAGE */
 
-static int acpi_ec_read(union acpi_ec *ec, u8 address, u32 * data)
+static int acpi_ec_transaction(union acpi_ec *ec, u8 command,
+                               const u8 *wdata, unsigned wdata_len,
+                               u8 *rdata, unsigned rdata_len)
 {
 	if (acpi_ec_poll_mode)
-		return acpi_ec_poll_read(ec, address, data);
+		return acpi_ec_poll_transaction(ec, command, wdata, wdata_len, rdata, rdata_len);
 	else
-		return acpi_ec_intr_read(ec, address, data);
+		return acpi_ec_intr_transaction(ec, command, wdata, wdata_len, rdata, rdata_len);
+}
+static int acpi_ec_read(union acpi_ec *ec, u8 address, u32 * data)
+{
+        int result;
+        u8 d;
+        result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_READ, &address, 1, &d, 1);
+        *data = d;
+        return result;
 }
 static int acpi_ec_write(union acpi_ec *ec, u8 address, u8 data)
 {
-	if (acpi_ec_poll_mode)
-		return acpi_ec_poll_write(ec, address, data);
-	else
-		return acpi_ec_intr_write(ec, address, data);
+        u8 wdata[2] = { address, data };
+        return acpi_ec_transaction(ec, ACPI_EC_COMMAND_WRITE, wdata, 2, NULL, 0);
 }
-static int acpi_ec_poll_read(union acpi_ec *ec, u8 address, u32 * data)
+
+static int acpi_ec_transaction_unlocked(union acpi_ec *ec, u8 command,
+                                             const u8 *wdata, unsigned wdata_len,
+                                             u8 *rdata, unsigned rdata_len)
 {
-	acpi_status status = AE_OK;
-	int result = 0;
-	u32 glk = 0;
+	int result;
 
+	acpi_hw_low_level_write(8, command, &ec->common.command_addr);
 
-	if (!ec || !data)
-		return -EINVAL;
+        result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
+	if (result)
+		return result;
 
-	*data = 0;
+        for (; wdata_len > 0; wdata_len --) {
 
-	if (ec->common.global_lock) {
-		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
-		if (ACPI_FAILURE(status))
-			return -ENODEV;
-	}
+                acpi_hw_low_level_write(8, *(wdata++), &ec->common.data_addr);
 
-	if (down_interruptible(&ec->poll.sem)) {
-		result = -ERESTARTSYS;
-		goto end_nosem;
-	}
-	
-	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_READ,
-				&ec->common.command_addr);
-	result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-	if (result)
-		goto end;
+                result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
+                if (result)
+                        return result;
+        }
 
-	acpi_hw_low_level_write(8, address, &ec->common.data_addr);
-	result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
-	if (result)
-		goto end;
 
-	acpi_hw_low_level_read(8, data, &ec->common.data_addr);
+        for (; rdata_len > 0; rdata_len --) {
+                u32 d;
 
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Read [%02x] from address [%02x]\n",
-			  *data, address));
+                result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
+                if (result)
+                        return result;
 
-      end:
-	up(&ec->poll.sem);
-end_nosem:
-	if (ec->common.global_lock)
-		acpi_release_global_lock(glk);
+                acpi_hw_low_level_read(8, &d, &ec->common.data_addr);
+                *(rdata++) = (u8) d;
+        }
 
-	return result;
+        return 0;
 }
 
-static int acpi_ec_poll_write(union acpi_ec *ec, u8 address, u8 data)
+static int acpi_ec_poll_transaction(union acpi_ec *ec, u8 command,
+                                    const u8 *wdata, unsigned wdata_len,
+                                    u8 *rdata, unsigned rdata_len)
 {
-	int result = 0;
 	acpi_status status = AE_OK;
+	int result;
 	u32 glk = 0;
 
-
-	if (!ec)
+	if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
 		return -EINVAL;
 
+        if (rdata)
+                memset(rdata, 0, rdata_len);
+
 	if (ec->common.global_lock) {
 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
 		if (ACPI_FAILURE(status))
 			return -ENODEV;
-	}
+        }
 
 	if (down_interruptible(&ec->poll.sem)) {
 		result = -ERESTARTSYS;
 		goto end_nosem;
 	}
-	
-	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_WRITE,
-				&ec->common.command_addr);
-	result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-	if (result)
-		goto end;
 
-	acpi_hw_low_level_write(8, address, &ec->common.data_addr);
-	result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-	if (result)
-		goto end;
-
-	acpi_hw_low_level_write(8, data, &ec->common.data_addr);
-	result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-	if (result)
-		goto end;
-
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Wrote [%02x] to address [%02x]\n",
-			  data, address));
-
-      end:
+        result = acpi_ec_transaction_unlocked(ec, command,
+                                              wdata, wdata_len,
+                                              rdata, rdata_len);
 	up(&ec->poll.sem);
+
 end_nosem:
 	if (ec->common.global_lock)
 		acpi_release_global_lock(glk);
@@ -413,16 +398,18 @@ end_nosem:
 	return result;
 }
 
-static int acpi_ec_intr_read(union acpi_ec *ec, u8 address, u32 * data)
+static int acpi_ec_intr_transaction(union acpi_ec *ec, u8 command,
+                                    const u8 *wdata, unsigned wdata_len,
+                                    u8 *rdata, unsigned rdata_len)
 {
-	int status = 0;
+	int status;
 	u32 glk;
 
-
-	if (!ec || !data)
+	if (!ec || (wdata_len && !wdata) || (rdata_len && !rdata))
 		return -EINVAL;
 
-	*data = 0;
+        if (rdata)
+                memset(rdata, 0, rdata_len);
 
 	if (ec->common.global_lock) {
 		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
@@ -438,72 +425,12 @@ static int acpi_ec_intr_read(union acpi_ec *ec, u8 address, u32 * data)
 		printk(KERN_DEBUG PREFIX "read EC, IB not empty\n");
 		goto end;
 	}
-	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_READ,
-				&ec->common.command_addr);
-	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-	if (status) {
-		printk(KERN_DEBUG PREFIX "read EC, IB not empty\n");
-	}
-
-	acpi_hw_low_level_write(8, address, &ec->common.data_addr);
-	status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
-	if (status) {
-		printk(KERN_DEBUG PREFIX "read EC, OB not full\n");
-		goto end;
-	}
-	acpi_hw_low_level_read(8, data, &ec->common.data_addr);
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Read [%02x] from address [%02x]\n",
-			  *data, address));
-
-      end:
-	up(&ec->intr.sem);
-
-	if (ec->common.global_lock)
-		acpi_release_global_lock(glk);
-
-	return status;
-}
-
-static int acpi_ec_intr_write(union acpi_ec *ec, u8 address, u8 data)
-{
-	int status = 0;
-	u32 glk;
-
-
-	if (!ec)
-		return -EINVAL;
-
-	if (ec->common.global_lock) {
-		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
-		if (ACPI_FAILURE(status))
-			return -ENODEV;
-	}
-
-	WARN_ON(in_interrupt());
-	down(&ec->intr.sem);
-
-	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-	if (status) {
-		printk(KERN_DEBUG PREFIX "write EC, IB not empty\n");
-	}
-	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_WRITE,
-				&ec->common.command_addr);
-	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-	if (status) {
-		printk(KERN_DEBUG PREFIX "write EC, IB not empty\n");
-	}
-
-	acpi_hw_low_level_write(8, address, &ec->common.data_addr);
-	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-	if (status) {
-		printk(KERN_DEBUG PREFIX "write EC, IB not empty\n");
-	}
 
-	acpi_hw_low_level_write(8, data, &ec->common.data_addr);
-
-	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Wrote [%02x] to address [%02x]\n",
-			  data, address));
+        status = acpi_ec_transaction_unlocked(ec, command,
+                                              wdata, wdata_len,
+                                              rdata, rdata_len);
 
+end:
 	up(&ec->intr.sem);
 
 	if (ec->common.global_lock)
@@ -554,106 +481,44 @@ int ec_write(u8 addr, u8 val)
 
 EXPORT_SYMBOL(ec_write);
 
-static int acpi_ec_query(union acpi_ec *ec, u32 * data)
-{
-	if (acpi_ec_poll_mode)
-		return acpi_ec_poll_query(ec, data);
-	else
-		return acpi_ec_intr_query(ec, data);
-}
-static int acpi_ec_poll_query(union acpi_ec *ec, u32 * data)
+extern int ec_transaction(u8 command,
+                          const u8 *wdata, unsigned wdata_len,
+                          u8 *rdata, unsigned rdata_len)
 {
-	int result = 0;
-	acpi_status status = AE_OK;
-	u32 glk = 0;
-
-
-	if (!ec || !data)
-		return -EINVAL;
-
-	*data = 0;
-
-	if (ec->common.global_lock) {
-		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
-		if (ACPI_FAILURE(status))
-			return -ENODEV;
-	}
-
-	/*
-	 * Query the EC to find out which _Qxx method we need to evaluate.
-	 * Note that successful completion of the query causes the ACPI_EC_SCI
-	 * bit to be cleared (and thus clearing the interrupt source).
-	 */
-	if (down_interruptible(&ec->poll.sem)) {
-		result = -ERESTARTSYS;
-		goto end_nosem;
-	}
-	
-	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_QUERY,
-				&ec->common.command_addr);
-	result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
-	if (result)
-		goto end;
+	union acpi_ec *ec;
 
-	acpi_hw_low_level_read(8, data, &ec->common.data_addr);
-	if (!*data)
-		result = -ENODATA;
+	if (!first_ec)
+		return -ENODEV;
 
-      end:
-	up(&ec->poll.sem);
-end_nosem:
-	if (ec->common.global_lock)
-		acpi_release_global_lock(glk);
+	ec = acpi_driver_data(first_ec);
 
-	return result;
+	return acpi_ec_transaction(ec, command, wdata, wdata_len, rdata, rdata_len);
 }
-static int acpi_ec_intr_query(union acpi_ec *ec, u32 * data)
-{
-	int status = 0;
-	u32 glk;
 
+EXPORT_SYMBOL(ec_transaction);
 
-	if (!ec || !data)
-		return -EINVAL;
-	*data = 0;
+static int acpi_ec_query(union acpi_ec *ec, u32 * data) {
+        int result;
+        u8 d;
 
-	if (ec->common.global_lock) {
-		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
-		if (ACPI_FAILURE(status))
-			return -ENODEV;
-	}
+        if (!ec || !data)
+                return -EINVAL;
 
-	down(&ec->intr.sem);
+        /*
+         * Query the EC to find out which _Qxx method we need to evaluate.
+         * Note that successful completion of the query causes the ACPI_EC_SCI
+         * bit to be cleared (and thus clearing the interrupt source).
+         */
 
-	status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
-	if (status) {
-		printk(KERN_DEBUG PREFIX "query EC, IB not empty\n");
-		goto end;
-	}
-	/*
-	 * Query the EC to find out which _Qxx method we need to evaluate.
-	 * Note that successful completion of the query causes the ACPI_EC_SCI
-	 * bit to be cleared (and thus clearing the interrupt source).
-	 */
-	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_QUERY,
-				&ec->common.command_addr);
-	status = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
-	if (status) {
-		printk(KERN_DEBUG PREFIX "query EC, OB not full\n");
-		goto end;
-	}
-
-	acpi_hw_low_level_read(8, data, &ec->common.data_addr);
-	if (!*data)
-		status = -ENODATA;
+        result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1);
+        if (result)
+                return result;
 
-      end:
-	up(&ec->intr.sem);
+        if (!d)
+                return -ENODATA;
 
-	if (ec->common.global_lock)
-		acpi_release_global_lock(glk);
-
-	return status;
+        *data = d;
+        return 0;
 }
 
 /* --------------------------------------------------------------------------
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 88b5dfd8ee12..2b0c955590fe 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -494,6 +494,9 @@ void acpi_pci_unregister_driver(struct acpi_pci_driver *driver);
 
 extern int ec_read(u8 addr, u8 *val);
 extern int ec_write(u8 addr, u8 val);
+extern int ec_transaction(u8 command,
+                          const u8 *wdata, unsigned wdata_len,
+                          u8 *rdata, unsigned rdata_len);
 
 #endif /*CONFIG_ACPI_EC*/