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Subject[PATCH 1/2] acpi,backlight: MSI S270 laptop support - ec_transaction()
From: Lennart Poettering <mzxreary@0pointer.de>

The attached patch unifies a few functions in ec.c:

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

They consist of very similar code which I unified as:

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.

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().
Based on 2.6.17.

Please comment and/or apply!

Lennart

Signed-off-by: Lennart Poettering <mzxreary@0pointer.de>
---
--- linux-source-2.6.17/drivers/acpi/ec.c 2006-06-18 03:49:35.000000000 +0200
+++ linux-source-2.6.17.lennart/drivers/acpi/ec.c 2006-08-10 01:28:22.000000000 +0200
@@ -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);
@@ -305,78 +305,46 @@ end:
}
#endif /* ACPI_FUTURE_USAGE */

+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_transaction(ec, command, wdata, wdata_len, rdata, rdata_len);
+ else
+ 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)
{
- if (acpi_ec_poll_mode)
- return acpi_ec_poll_read(ec, address, data);
- else
- return acpi_ec_intr_read(ec, address, 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_poll_transaction(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;
unsigned long flags = 0;
u32 glk = 0;

- ACPI_FUNCTION_TRACE("acpi_ec_read");
+ ACPI_FUNCTION_TRACE("acpi_ec_poll_transaction");

- if (!ec || !data)
+ if (!ec || !wdata || !wdata_len || (rdata_len && !rdata))
return_VALUE(-EINVAL);

- *data = 0;
-
- if (ec->common.global_lock) {
- status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
- if (ACPI_FAILURE(status))
- return_VALUE(-ENODEV);
- }
-
- spin_lock_irqsave(&ec->poll.lock, flags);
-
- 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;
-
- 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);
-
- ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Read [%02x] from address [%02x]\n",
- *data, address));
-
- end:
- spin_unlock_irqrestore(&ec->poll.lock, flags);
-
- if (ec->common.global_lock)
- acpi_release_global_lock(glk);
-
- return_VALUE(result);
-}
-
-static int acpi_ec_poll_write(union acpi_ec *ec, u8 address, u8 data)
-{
- int result = 0;
- acpi_status status = AE_OK;
- unsigned long flags = 0;
- u32 glk = 0;
-
- ACPI_FUNCTION_TRACE("acpi_ec_write");
-
- if (!ec)
- return_VALUE(-EINVAL);
+ if (rdata)
+ memset(rdata, 0, rdata_len);

if (ec->common.global_lock) {
status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
@@ -386,25 +354,35 @@ static int acpi_ec_poll_write(union acpi

spin_lock_irqsave(&ec->poll.lock, flags);

- 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);
+ acpi_hw_low_level_write(8, command, &ec->common.command_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));
+ while (wdata_len > 0) {

+ acpi_hw_low_level_write(8, *(wdata++), &ec->common.data_addr);
+
+ result = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
+ if (result)
+ goto end;
+
+ wdata_len--;
+ }
+
+ while (rdata_len > 0) {
+ u32 d;
+
+ result = acpi_ec_wait(ec, ACPI_EC_EVENT_OBF);
+ if (result)
+ goto end;
+
+ acpi_hw_low_level_read(8, &d, &ec->common.data_addr);
+ *(rdata++) = (u8) d;
+
+ rdata_len--;
+ }
+
end:
spin_unlock_irqrestore(&ec->poll.lock, flags);

@@ -414,17 +392,20 @@ static int acpi_ec_poll_write(union acpi
return_VALUE(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;
u32 glk;

- ACPI_FUNCTION_TRACE("acpi_ec_read");
+ ACPI_FUNCTION_TRACE("acpi_ec_intr_transaction");

- if (!ec || !data)
+ if (!ec || !wdata || !wdata_len || (rdata_len && !rdata))
return_VALUE(-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);
@@ -440,22 +421,39 @@ static int acpi_ec_intr_read(union acpi_
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);
+
+ acpi_hw_low_level_write(8, command, &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");
+ goto end;
}

- 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));
+ while (wdata_len > 0) {
+
+ acpi_hw_low_level_write(8, *(wdata++), &ec->common.data_addr);
+
+ status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
+ if (status) {
+ printk(KERN_DEBUG PREFIX "read EC, IB not empty\n");
+ goto end;
+ }
+
+ wdata_len--;
+ }
+
+ while (rdata_len > 0) {
+ u32 d;
+
+ 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, &d, &ec->common.data_addr);
+ *(rdata++) = (u8) d;
+ rdata_len--;
+ }

end:
up(&ec->intr.sem);
@@ -466,55 +464,6 @@ static int acpi_ec_intr_read(union acpi_
return_VALUE(status);
}

-static int acpi_ec_intr_write(union acpi_ec *ec, u8 address, u8 data)
-{
- int status = 0;
- u32 glk;
-
- ACPI_FUNCTION_TRACE("acpi_ec_write");
-
- if (!ec)
- return_VALUE(-EINVAL);
-
- if (ec->common.global_lock) {
- status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
- if (ACPI_FAILURE(status))
- return_VALUE(-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));
-
- up(&ec->intr.sem);
-
- if (ec->common.global_lock)
- acpi_release_global_lock(glk);
-
- return_VALUE(status);
-}
-
/*
* Externally callable EC access functions. For now, assume 1 EC only
*/
@@ -557,106 +506,41 @@ 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)
+int ec_transaction(u8 command,
+ const u8 *wdata, unsigned wdata_len,
+ u8 *rdata, unsigned rdata_len)
{
- int result = 0;
- acpi_status status = AE_OK;
- unsigned long flags = 0;
- u32 glk = 0;
-
- ACPI_FUNCTION_TRACE("acpi_ec_query");
-
- if (!ec || !data)
- return_VALUE(-EINVAL);
-
- *data = 0;
-
- if (ec->common.global_lock) {
- status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
- if (ACPI_FAILURE(status))
- return_VALUE(-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).
- */
- spin_lock_irqsave(&ec->poll.lock, flags);
-
- 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;
-
- acpi_hw_low_level_read(8, data, &ec->common.data_addr);
- if (!*data)
- result = -ENODATA;
+ union acpi_ec *ec;

- end:
- spin_unlock_irqrestore(&ec->poll.lock, flags);
+ if (!first_ec)
+ return -ENODEV;

- if (ec->common.global_lock)
- acpi_release_global_lock(glk);
+ ec = acpi_driver_data(first_ec);

- return_VALUE(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;
-
- ACPI_FUNCTION_TRACE("acpi_ec_query");

- if (!ec || !data)
- return_VALUE(-EINVAL);
- *data = 0;
+EXPORT_SYMBOL(ec_transaction);

- if (ec->common.global_lock) {
- status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
- if (ACPI_FAILURE(status))
- return_VALUE(-ENODEV);
- }
-
- down(&ec->intr.sem);
-
- status = acpi_ec_wait(ec, ACPI_EC_EVENT_IBE);
- if (status) {
- printk(KERN_DEBUG PREFIX "query EC, IB not empty\n");
- goto end;
- }
+static int acpi_ec_query(union acpi_ec *ec, u32 * data)
+{
+ int result;
+ u8 d;
+
/*
* 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;
+ if ((result = acpi_ec_transaction(ec, ACPI_EC_COMMAND_QUERY, NULL, 0, &d, 1)))
+ return_VALUE(result);

- end:
- up(&ec->intr.sem);
+ if (!d)
+ return_VALUE(-ENODATA);

- if (ec->common.global_lock)
- acpi_release_global_lock(glk);
-
- return_VALUE(status);
+ *data = d;
+ return_VALUE(0);
}

/* --------------------------------------------------------------------------
--- linux-source-2.6.17/include/linux/acpi.h 2006-06-18 03:49:35.000000000 +0200
+++ linux-source-2.6.17.lennart/include/linux/acpi.h 2006-08-08 17:45:24.000000000 +0200
@@ -486,6 +486,9 @@ void acpi_pci_unregister_driver(struct a

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*/

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