Subject: [PATCH] [acpi ec] Add interface for reading from device

- Add acpi_ec_read() for reading from EC device
- Add common __read() that does the same low-level access no
  matter whether we're using the interrupt or polling method
  (depends on ->e_wait() method)
  - Note that this uses ->e_sem for both access methods
- Add ec_read() function that is exported to other users
  (to be compatible)

Signed-off-by: Patrick Mochel <mochel@linux.intel.com>

---

 drivers/acpi/drivers/ec/Makefile |    2 -
 drivers/acpi/drivers/ec/read.c   |   83 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 84 insertions(+), 1 deletions(-)
 create mode 100644 drivers/acpi/drivers/ec/read.c

applies-to: 6bf691e3603a4db64df31fffb2c8f08d60ce36ee
dc17eabe4e5d91f5e3e55f88bd7eff34f0c4c0ef
diff --git a/drivers/acpi/drivers/ec/Makefile b/drivers/acpi/drivers/ec/Makefile
index c2ee992..26f3b7b 100644
--- a/drivers/acpi/drivers/ec/Makefile
+++ b/drivers/acpi/drivers/ec/Makefile
@@ -2,7 +2,7 @@ obj-$(CONFIG_ACPI_EC)	+= ec.o
 
 ec-y			:= driver.o device.o event.o poll.o intr.o
 ec-y			+= setup.o
-ec-y			+= resource.o gpe.o
+ec-y			+= resource.o gpe.o read.o 
 
 ec-$(CONFIG_ACPI_DM_PROC)	+= proc.o
 ec-$(CONFIG_ACPI_DM_SYSFS)	+= sysfs.o
diff --git a/drivers/acpi/drivers/ec/read.c b/drivers/acpi/drivers/ec/read.c
new file mode 100644
index 0000000..afda8a5
--- /dev/null
+++ b/drivers/acpi/drivers/ec/read.c
@@ -0,0 +1,83 @@
+/***
+ * drivers/acpi/drivers/ec/intr.c - Interrupt-driven EC driver
+ *
+ * Copyright (C) 2006 Patrick Mochel
+ *
+ * Based on drivers/acpi/ec.c, which was 
+ *
+ *  Copyright (C) 2004 Luming Yu <luming.yu@intel.com>
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *
+ * This file is released under the GPLv2.
+ */
+
+#include "ec.h"
+
+
+static int __read(struct acpi_ec * ec, u8 addr, u32 * data)
+{
+	int ret;
+
+	ret = ec->e_wait(ec, ACPI_EC_EVENT_IBE);
+	if (ret) {
+		dbg("EC Read, IB not empty");
+		return ret;
+	}
+
+	acpi_hw_low_level_write(8, ACPI_EC_COMMAND_READ, &ec->e_command);
+	ret = ec->e_wait(ec, ACPI_EC_EVENT_IBE);
+	if (ret)
+		dbg("EC Read, IB not empty");
+
+	acpi_hw_low_level_write(8, addr, &ec->e_data);
+	ret = ec->e_wait(ec, ACPI_EC_EVENT_OBF);
+	if (ret) {
+		dbg("EC Read, OB not full");
+		return ret;
+	}
+	acpi_hw_low_level_read(8, data, &ec->e_data);
+	dbg("Read [%#02x] from address [%#02x]", *data, address);
+	return 0;
+}
+
+
+int acpi_ec_read(struct acpi_ec * ec, u8 addr, u32 * data)
+{
+	acpi_status status;
+	u32 glk;
+	int ret;
+
+	if (ec->e_global_lock) {
+		status = acpi_acquire_global_lock(ACPI_EC_UDELAY_GLK, &glk);
+		if (ACPI_FAILURE(status))
+			return -ENODEV;
+	}
+
+	down(&ec->e_sem);
+	ret = __read(ec, addr, data);
+	up(&ec->e_sem);
+
+	if (ec->e_global_lock)
+		acpi_release_global_lock(glk);
+	return ret;
+}
+
+/*
+ * Externally callable EC access functions. For now, assume 1 EC only
+ */
+int ec_read(u8 addr, u8 * val)
+{
+	int ret;
+	u32 data;
+
+	if (!first_ec)
+		return -ENODEV;
+
+	ret = acpi_ec_read(first_ec, addr, &data);
+	if (!ret)
+		*val = data;
+	return ret;
+}
+
+EXPORT_SYMBOL(ec_read);
---
0.99.9.GIT