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authorBob Moore <Robert.Moore@intel.com>2014-09-23 06:35:47 +0400
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2014-09-25 00:53:46 +0400
commit75ec6e55f1384548311a13ce4fcb39c516053314 (patch)
tree0165f3ba0f3fe31a1d27d17e4fee1a379df83c40 /drivers/acpi/acpica/exfield.c
parent0f33be009b89d2268e94194dc4fd01a7851b6d51 (diff)
downloadlinux-75ec6e55f1384548311a13ce4fcb39c516053314.tar.xz
ACPICA: Update to GPIO region handler interface.
Changes to correct several GPIO issues: 1) The update_rule in a GPIO field definition is now ignored; a read-modify-write operation is never performed for GPIO fields. (Internally, this means that the field assembly/disassembly code is completely bypassed for GPIO.) 2) The Address parameter passed to a GPIO region handler is now the bit offset of the field from a previous Connection() operator. Thus, it becomes a "Pin Number Index" into the Connection() resource descriptor. 3) The bit_width parameter passed to a GPIO region handler is now the exact bit width of the GPIO field. Thus, it can be interpreted as "number of pins". Overall, we can now say that the region handler interface to GPIO handlers is a raw "bit/pin" addressed interface, not a byte-addressed interface like the system_memory handler interface. Signed-off-by: Bob Moore <robert.moore@intel.com> Signed-off-by: Lv Zheng <lv.zheng@intel.com> Cc: 3.15+ <stable@vger.kernel.org> # 3.15+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Diffstat (limited to 'drivers/acpi/acpica/exfield.c')
-rw-r--r--drivers/acpi/acpica/exfield.c67
1 files changed, 67 insertions, 0 deletions
diff --git a/drivers/acpi/acpica/exfield.c b/drivers/acpi/acpica/exfield.c
index 6907ce0c704c..b994845ed359 100644
--- a/drivers/acpi/acpica/exfield.c
+++ b/drivers/acpi/acpica/exfield.c
@@ -253,6 +253,37 @@ acpi_ex_read_data_from_field(struct acpi_walk_state * walk_state,
buffer = &buffer_desc->integer.value;
}
+ if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
+ (obj_desc->field.region_obj->region.space_id ==
+ ACPI_ADR_SPACE_GPIO)) {
+ /*
+ * For GPIO (general_purpose_io), the Address will be the bit offset
+ * from the previous Connection() operator, making it effectively a
+ * pin number index. The bit_length is the length of the field, which
+ * is thus the number of pins.
+ */
+ ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
+ "GPIO FieldRead [FROM]: Pin %u Bits %u\n",
+ obj_desc->field.pin_number_index,
+ obj_desc->field.bit_length));
+
+ /* Lock entire transaction if requested */
+
+ acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
+
+ /* Perform the write */
+
+ status = acpi_ex_access_region(obj_desc, 0,
+ (u64 *)buffer, ACPI_READ);
+ acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
+ if (ACPI_FAILURE(status)) {
+ acpi_ut_remove_reference(buffer_desc);
+ } else {
+ *ret_buffer_desc = buffer_desc;
+ }
+ return_ACPI_STATUS(status);
+ }
+
ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
"FieldRead [TO]: Obj %p, Type %X, Buf %p, ByteLen %X\n",
obj_desc, obj_desc->common.type, buffer,
@@ -413,6 +444,42 @@ acpi_ex_write_data_to_field(union acpi_operand_object *source_desc,
*result_desc = buffer_desc;
return_ACPI_STATUS(status);
+ } else if ((obj_desc->common.type == ACPI_TYPE_LOCAL_REGION_FIELD) &&
+ (obj_desc->field.region_obj->region.space_id ==
+ ACPI_ADR_SPACE_GPIO)) {
+ /*
+ * For GPIO (general_purpose_io), we will bypass the entire field
+ * mechanism and handoff the bit address and bit width directly to
+ * the handler. The Address will be the bit offset
+ * from the previous Connection() operator, making it effectively a
+ * pin number index. The bit_length is the length of the field, which
+ * is thus the number of pins.
+ */
+ if (source_desc->common.type != ACPI_TYPE_INTEGER) {
+ return_ACPI_STATUS(AE_AML_OPERAND_TYPE);
+ }
+
+ ACPI_DEBUG_PRINT((ACPI_DB_BFIELD,
+ "GPIO FieldWrite [FROM]: (%s:%X), Val %.8X [TO]: Pin %u Bits %u\n",
+ acpi_ut_get_type_name(source_desc->common.
+ type),
+ source_desc->common.type,
+ (u32)source_desc->integer.value,
+ obj_desc->field.pin_number_index,
+ obj_desc->field.bit_length));
+
+ buffer = &source_desc->integer.value;
+
+ /* Lock entire transaction if requested */
+
+ acpi_ex_acquire_global_lock(obj_desc->common_field.field_flags);
+
+ /* Perform the write */
+
+ status = acpi_ex_access_region(obj_desc, 0,
+ (u64 *)buffer, ACPI_WRITE);
+ acpi_ex_release_global_lock(obj_desc->common_field.field_flags);
+ return_ACPI_STATUS(status);
}
/* Get a pointer to the data to be written */