[PATCH 07/22 v4] Input: atmel_mxt_ts - optimize reading objects in object sysfs entry

From: Daniel Kurtz
Date: Mon Jun 18 2012 - 00:09:13 EST


Read each object in a single i2c transaction instead of byte-by-byte

Signed-off-by: Daniel Kurtz <djkurtz@xxxxxxxxxxxx>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 35 ++++++++++++-----------------
1 files changed, 15 insertions(+), 20 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 472ab29..8c99d6d 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -478,20 +478,6 @@ static int mxt_read_message(struct mxt_data *data,
sizeof(struct mxt_message), message);
}

-static int mxt_read_object(struct mxt_data *data,
- u8 type, u8 offset, u8 *val)
-{
- struct mxt_object *object;
- u16 reg;
-
- object = mxt_get_object(data, type);
- if (!object)
- return -EINVAL;
-
- reg = object->start_address;
- return __mxt_read_reg(data->client, reg + offset, 1, val);
-}
-
static int mxt_write_object(struct mxt_data *data,
u8 type, u8 offset, u8 val)
{
@@ -899,7 +885,14 @@ static ssize_t mxt_object_show(struct device *dev,
int i, j;
int error;
u8 val;
+ u8 *obuf;
+
+ /* Pre-allocate buffer large enough to hold max sized object. */
+ obuf = kmalloc(256, GFP_KERNEL);
+ if (!obuf)
+ return -ENOMEM;

+ error = 0;
for (i = 0; i < data->info.object_num; i++) {
object = data->object_table + i;

@@ -913,20 +906,22 @@ static ssize_t mxt_object_show(struct device *dev,
continue;
}

+ error = __mxt_read_reg(data->client, object->start_address,
+ object->size + 1, obuf);
+ if (error)
+ break;
+
for (j = 0; j < object->size + 1; j++) {
- error = mxt_read_object(data,
- object->type, j, &val);
- if (error)
- return error;
+ val = obuf[j];

count += scnprintf(buf + count, PAGE_SIZE - count,
"\t[%2d]: %02x (%d)\n", j, val, val);
}
-
count += scnprintf(buf + count, PAGE_SIZE - count, "\n");
}

- return count;
+ kfree(obuf);
+ return error ?: count;
}

static int mxt_load_fw(struct device *dev, const char *fn)
--
1.7.7.3

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