[PATCH 18/40] Input: atmel_mxt_ts - Add support for dynamic message size

From: Nick Dyer
Date: Fri Feb 22 2013 - 13:18:30 EST


maXTouch chips and firmware versions have different sizes of message buffer
depending on the objects used, therefore it can't be hardcoded in the driver.
Allocate a buffer on probe instead.

Signed-off-by: Nick Dyer <nick.dyer@xxxxxxxxxxx>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 97 +++++++++++++++++-------------
1 file changed, 55 insertions(+), 42 deletions(-)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 60231bf..c879778 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -221,11 +221,6 @@ struct mxt_object {
u8 num_report_ids;
} __packed;

-struct mxt_message {
- u8 reportid;
- u8 message[7];
-};
-
enum mxt_device_state { INIT, APPMODE, BOOTLOADER, FAILED, SHUTDOWN };

/* Each client has this additional data */
@@ -247,8 +242,10 @@ struct mxt_data {
u32 info_crc;
u8 bootloader_addr;
struct t7_config t7_cfg;
+ u8 *msg_buf;

/* Cached parameters from object table */
+ u8 T5_msg_size;
u8 T6_reportid;
u16 T6_address;
u16 T7_address;
@@ -309,10 +306,10 @@ static bool mxt_object_readable(unsigned int type)
}
}

-static void mxt_dump_message(struct device *dev, struct mxt_message *message)
+static void mxt_dump_message(struct mxt_data *data, u8 *message)
{
- dev_dbg(dev, "MXT MSG: %*ph\n",
- sizeof(struct mxt_message), message);
+ dev_dbg(&data->client->dev, "MXT MSG: %*ph\n",
+ data->T5_msg_size, message);
}

static int mxt_bootloader_read(struct mxt_data *data, u8 *val, unsigned int count)
@@ -565,8 +562,7 @@ mxt_get_object(struct mxt_data *data, u8 type)
return NULL;
}

-static int mxt_read_message(struct mxt_data *data,
- struct mxt_message *message)
+static int mxt_read_message(struct mxt_data *data, u8 *message)
{
struct mxt_object *object;
u16 reg;
@@ -577,7 +573,7 @@ static int mxt_read_message(struct mxt_data *data,

reg = object->start_address;
return __mxt_read_reg(data->client, reg,
- sizeof(struct mxt_message), message);
+ data->T5_msg_size, message);
}

static void mxt_input_sync(struct input_dev *input_dev)
@@ -586,12 +582,12 @@ static void mxt_input_sync(struct input_dev *input_dev)
input_sync(input_dev);
}

-static void mxt_input_touchevent(struct mxt_data *data,
- struct mxt_message *message, int id)
+static void mxt_input_touchevent(struct mxt_data *data, u8 *message)
{
struct device *dev = &data->client->dev;
- u8 status = message->message[0];
struct input_dev *input_dev = data->input_dev;
+ int id;
+ u8 status;
int x;
int y;
int area;
@@ -601,16 +597,18 @@ static void mxt_input_touchevent(struct mxt_data *data,
if (!input_dev)
return;

- x = (message->message[1] << 4) | ((message->message[3] >> 4) & 0xf);
- y = (message->message[2] << 4) | ((message->message[3] & 0xf));
+ id = message[0] - data->T9_reportid_min;
+ status = message[1];
+ x = (message[2] << 4) | ((message[4] >> 4) & 0xf);
+ y = (message[3] << 4) | ((message[4] & 0xf));

if (data->max_x < 1024)
x >>= 2;
if (data->max_y < 1024)
y >>= 2;

- area = message->message[4];
- amplitude = message->message[5];
+ area = message[5];
+ amplitude = message[6];

dev_dbg(dev,
"[%u] %c%c%c%c%c%c%c%c x: %5u y: %5u area: %3u amp: %3u\n",
@@ -654,28 +652,28 @@ static u16 mxt_extract_T6_csum(const u8 *csum)
return csum[0] | (csum[1] << 8) | (csum[2] << 16);
}

-static bool mxt_is_T9_message(struct mxt_data *data, struct mxt_message *msg)
+static bool mxt_is_T9_message(struct mxt_data *data, u8 *msg)
{
- u8 id = msg->reportid;
+ u8 id = msg[0];
return (id >= data->T9_reportid_min && id <= data->T9_reportid_max);
}

static irqreturn_t mxt_process_messages_until_invalid(struct mxt_data *data)
{
- struct mxt_message message;
- const u8 *payload = &message.message[0];
+ u8 *message = &data->msg_buf[0];
+ const u8 *payload = &data->msg_buf[1];
struct device *dev = &data->client->dev;
u8 reportid;
bool update_input = false;
bool handled;

do {
- if (mxt_read_message(data, &message)) {
+ if (mxt_read_message(data, message)) {
dev_err(dev, "Failed to read message\n");
return IRQ_NONE;
}

- reportid = message.reportid;
+ reportid = message[0];
handled = false;

if (reportid == data->T6_reportid) {
@@ -684,15 +682,14 @@ static irqreturn_t mxt_process_messages_until_invalid(struct mxt_data *data)
dev_dbg(dev, "Status: %02x Config Checksum: %06x\n",
status, data->config_crc);
handled = true;
- } else if (mxt_is_T9_message(data, &message)) {
- int id = reportid - data->T9_reportid_min;
- mxt_input_touchevent(data, &message, id);
+ } else if (mxt_is_T9_message(data, message)) {
+ mxt_input_touchevent(data, message);
update_input = true;
handled = true;
}

if (!handled || data->debug_enabled)
- mxt_dump_message(dev, &message);
+ mxt_dump_message(data, message);
} while (reportid != MXT_RPTID_NOMSG);

if (update_input)
@@ -1110,16 +1107,15 @@ recheck:
static int mxt_make_highchg(struct mxt_data *data)
{
struct device *dev = &data->client->dev;
- struct mxt_message message;
int count = 10;
int error;

/* Read dummy message to make high CHG pin */
do {
- error = mxt_read_message(data, &message);
+ error = mxt_read_message(data, data->msg_buf);
if (error)
return error;
- } while (message.reportid != MXT_RPTID_NOMSG && --count);
+ } while (data->msg_buf[0] != MXT_RPTID_NOMSG && --count);

if (!count) {
dev_err(dev, "CHG pin isn't cleared\n");
@@ -1143,6 +1139,19 @@ static int mxt_get_info(struct mxt_data *data)
return 0;
}

+static void mxt_free_object_table(struct mxt_data *data)
+{
+ kfree(data->object_table);
+ data->object_table = NULL;
+ kfree(data->msg_buf);
+ data->msg_buf = NULL;
+ data->T5_msg_size = 0;
+ data->T6_reportid = 0;
+ data->T7_address = 0;
+ data->T9_reportid_min = 0;
+ data->T9_reportid_max = 0;
+}
+
static int mxt_get_object_table(struct mxt_data *data)
{
struct i2c_client *client = data->client;
@@ -1183,6 +1192,9 @@ static int mxt_get_object_table(struct mxt_data *data)
OBP_INSTANCES(object), min_id, max_id);

switch (object->type) {
+ case MXT_GEN_MESSAGE_T5:
+ /* CRC not enabled, therefore don't read last byte */
+ data->T5_msg_size = OBP_SIZE(object) - 1;
case MXT_GEN_COMMAND_T6:
data->T6_reportid = min_id;
data->T6_address = object->start_address;
@@ -1203,17 +1215,18 @@ static int mxt_get_object_table(struct mxt_data *data)
data->mem_size = end_address + 1;
}

- return 0;
-}
+ data->msg_buf = kzalloc(data->T5_msg_size, GFP_KERNEL);
+ if (!data->msg_buf) {
+ dev_err(&client->dev, "Failed to allocate message buffer\n");
+ error = -ENOMEM;
+ goto free_object_table;
+ }

-static void mxt_free_object_table(struct mxt_data *data)
-{
- kfree(data->object_table);
- data->object_table = NULL;
- data->T6_reportid = 0;
- data->T9_reportid_min = 0;
- data->T9_reportid_max = 0;
+ return 0;

+free_object_table:
+ mxt_free_object_table(data);
+ return error;
}

static int mxt_read_t9_resolution(struct mxt_data *data)
@@ -1830,7 +1843,7 @@ err_unregister_device:
err_free_irq:
free_irq(client->irq, data);
err_free_object:
- kfree(data->object_table);
+ mxt_free_object_table(data);
err_free_mem:
kfree(data);
return error;
@@ -1844,7 +1857,7 @@ static int mxt_remove(struct i2c_client *client)
sysfs_remove_group(&client->dev.kobj, &mxt_attr_group);
free_irq(data->irq, data);
input_unregister_device(data->input_dev);
- kfree(data->object_table);
+ mxt_free_object_table(data);
kfree(data);

return 0;
--
1.7.10.4

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