[PATCH 04/53] Input: atmel_mxt_ts - define helper functions for size and instances

From: Nick Dyer
Date: Wed Jun 05 2013 - 13:51:32 EST


From: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>

These two object table entry fields are reported 1 less than their value.
When used, however, we always want the actual size and instances.

To keep the object size and instances 1-byte fields, and thus preserve
the object-table struct's 6-byte packed alignment, add some convenient
accessor functions that do the +1 every time these fields are accessed.

Signed-off-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
Signed-off-by: Nick Dyer <nick.dyer@xxxxxxxxxxx>
Acked-by: Benson Leung <bleung@xxxxxxxxxxxx>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 35 ++++++++++++++++++++----------
1 file changed, 24 insertions(+), 11 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 2a06657..7de3b47 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -2,6 +2,8 @@
* Atmel maXTouch Touchscreen driver
*
* Copyright (C) 2010 Samsung Electronics Co.Ltd
+ * Copyright (C) 2012 Google, Inc.
+ *
* Author: Joonyoung Shim <jy0922.shim@xxxxxxxxxxx>
*
* This program is free software; you can redistribute it and/or modify it
@@ -227,8 +229,8 @@ struct mxt_info {
struct mxt_object {
u8 type;
u16 start_address;
- u8 size; /* Size of each instance - 1 */
- u8 instances; /* Number of instances - 1 */
+ u8 size_minus_one;
+ u8 instances_minus_one;
u8 num_report_ids;
} __packed;

@@ -257,6 +259,16 @@ struct mxt_data {
u8 T19_reportid;
};

+static inline size_t mxt_obj_size(const struct mxt_object *obj)
+{
+ return obj->size_minus_one + 1;
+}
+
+static inline size_t mxt_obj_instances(const struct mxt_object *obj)
+{
+ return obj->instances_minus_one + 1;
+}
+
static bool mxt_object_readable(unsigned int type)
{
switch (type) {
@@ -499,7 +511,7 @@ static int mxt_write_object(struct mxt_data *data,
u16 reg;

object = mxt_get_object(data, type);
- if (!object || offset >= object->size + 1)
+ if (!object || offset >= mxt_obj_size(object))
return -EINVAL;

reg = object->start_address;
@@ -641,7 +653,7 @@ static int mxt_check_reg_init(struct mxt_data *data)
if (!mxt_object_writable(object->type))
continue;

- size = (object->size + 1) * (object->instances + 1);
+ size = mxt_obj_size(object) * mxt_obj_instances(object);
if (index + size > pdata->config_length) {
dev_err(dev, "Not enough config data!\n");
return -EINVAL;
@@ -718,7 +730,7 @@ static int mxt_get_object_table(struct mxt_data *data)
if (object->num_report_ids) {
min_id = reportid;
reportid += object->num_report_ids *
- (object->instances + 1);
+ mxt_obj_instances(object);
max_id = reportid - 1;
} else {
min_id = 0;
@@ -727,8 +739,9 @@ static int mxt_get_object_table(struct mxt_data *data)

dev_dbg(&data->client->dev,
"Type %2d Start %3d Size %3d Instances %2d ReportIDs %3u : %3u\n",
- object->type, object->start_address, object->size + 1,
- object->instances + 1, min_id, max_id);
+ object->type, object->start_address,
+ mxt_obj_size(object), mxt_obj_instances(object),
+ min_id, max_id);

switch (object->type) {
case MXT_GEN_COMMAND_T6:
@@ -865,11 +878,11 @@ static ssize_t mxt_show_instance(char *buf, int count,
{
int i;

- if (object->instances > 0)
+ if (mxt_obj_instances(object) > 1)
count += scnprintf(buf + count, PAGE_SIZE - count,
"Instance %u\n", instance);

- for (i = 0; i < object->size + 1; i++)
+ for (i = 0; i < mxt_obj_size(object); i++)
count += scnprintf(buf + count, PAGE_SIZE - count,
"\t[%2u]: %02x (%d)\n", i, val[i], val[i]);
count += scnprintf(buf + count, PAGE_SIZE - count, "\n");
@@ -902,8 +915,8 @@ static ssize_t mxt_object_show(struct device *dev,
count += scnprintf(buf + count, PAGE_SIZE - count,
"T%u:\n", object->type);

- for (j = 0; j < object->instances + 1; j++) {
- u16 size = object->size + 1;
+ for (j = 0; j < mxt_obj_instances(object); j++) {
+ u16 size = mxt_obj_size(object);
u16 addr = object->start_address + j * size;

error = __mxt_read_reg(data->client, addr, size, obuf);
--
1.7.10.4

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