lkml.org 
[lkml]   [2012]   [Jun]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [PATCH 18/21 v5] Input: atmel_mxt_ts - cache T9 reportid range when reading object table
    Hi Daniel,

    > Streamline interrupt processing by caching the T9 reportid range when
    > first reading the object table.
    >
    > In the process, refactor reading the object descriptor table.
    > First, since the object_table entries are now exactly the same layout
    > in device memory and in the driver, allocate an appropriately sized
    > array and fetch the entire table directly into it in a single i2c
    > transaction. Since a 6 byte table object requires 10 bytes to read,
    > doing this dramatically reduces overhead.
    >
    > Note: The cached T9 reportid's are initialized to 0, which is an invalid
    > reportid. Thus, the checks in the interrupt handler will always fail for
    > devices that do not support the T9 object. Therefore, after doing a
    > firmware update, the old object table is destroyed and all cached object
    > values are reset to 0, before reading the new object table, in case
    > the new firmware does not have the old objects.
    >
    > This patch tested on an MXT224E.
    >
    > Signed-off-by: Daniel Kurtz <djkurtz@chromium.org>
    > ---
    > drivers/input/touchscreen/atmel_mxt_ts.c | 80 +++++++++++++++++-------------
    > 1 files changed, 45 insertions(+), 35 deletions(-)
    >
    > diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
    > index 7b042e5..4da12a9 100644
    > --- a/drivers/input/touchscreen/atmel_mxt_ts.c
    > +++ b/drivers/input/touchscreen/atmel_mxt_ts.c
    > @@ -227,13 +227,10 @@ struct mxt_info {
    > struct mxt_object {
    > u8 type;
    > u16 start_address;
    > - u8 size;
    > - u8 instances;
    > + u8 size; /* Size of each instance - 1 */
    > + u8 instances; /* Number of instances - 1 */
    > u8 num_report_ids;
    > -
    > - /* to map object and message */
    > - u8 max_reportid;
    > -};
    > +} __packed;
    >
    > struct mxt_message {
    > u8 reportid;
    > @@ -251,6 +248,10 @@ struct mxt_data {
    > unsigned int irq;
    > unsigned int max_x;
    > unsigned int max_y;
    > +
    > + /* Cached parameters from object table */
    > + u8 T9_reportid_min;
    > + u8 T9_reportid_max;
    > };
    >
    > static bool mxt_object_readable(unsigned int type)
    > @@ -458,13 +459,6 @@ static int mxt_write_reg(struct i2c_client *client, u16 reg, u8 val)
    > return __mxt_write_reg(client, reg, 1, &val);
    > }
    >
    > -static int mxt_read_object_table(struct i2c_client *client,
    > - u16 reg, u8 *object_buf)
    > -{
    > - return __mxt_read_reg(client, reg, MXT_OBJECT_SIZE,
    > - object_buf);
    > -}
    > -
    > static struct mxt_object *
    > mxt_get_object(struct mxt_data *data, u8 type)
    > {
    > @@ -563,7 +557,6 @@ static irqreturn_t mxt_interrupt(int irq, void *dev_id)
    > {
    > struct mxt_data *data = dev_id;
    > struct mxt_message message;
    > - struct mxt_object *object;
    > struct device *dev = &data->client->dev;
    > int id;
    > u8 reportid;
    > @@ -578,13 +571,8 @@ static irqreturn_t mxt_interrupt(int irq, void *dev_id)
    >
    > reportid = message.reportid;
    >
    > - /* whether reportid is thing of MXT_TOUCH_MULTI_T9 */
    > - object = mxt_get_object(data, MXT_TOUCH_MULTI_T9);
    > - if (!object)
    > - goto end;
    > -
    > - max_reportid = object->max_reportid;
    > - min_reportid = max_reportid - object->num_report_ids + 1;
    > + max_reportid = data->T9_reportid_max;
    > + min_reportid = data->T9_reportid_min;
    > id = reportid - min_reportid;
    >
    > if (reportid >= min_reportid && reportid <= max_reportid)
    > @@ -719,30 +707,49 @@ static int mxt_get_info(struct mxt_data *data)
    >
    > static int mxt_get_object_table(struct mxt_data *data)
    > {
    > + struct i2c_client *client = data->client;
    > + size_t table_size;
    > int error;
    > int i;
    > - u16 reg;
    > - u8 reportid = 0;
    > - u8 buf[MXT_OBJECT_SIZE];
    > + u8 reportid;
    >
    > + table_size = data->info.object_num * sizeof(struct mxt_object);
    > + error = __mxt_read_reg(client, MXT_OBJECT_START, table_size,
    > + data->object_table);
    > + if (error) {
    > + kfree(data->object_table);
    > + data->object_table = NULL;
    > + return error;

    Freeing the object table here does not look right. Either free it in
    mxt_initialize() or move the allocation into this function as well.

    > + }
    > +
    > + /* Valid Report IDs start counting from 1 */
    > + reportid = 1;
    > for (i = 0; i < data->info.object_num; i++) {
    > struct mxt_object *object = data->object_table + i;
    > + u8 min_id, max_id;
    >
    > - reg = MXT_OBJECT_START + MXT_OBJECT_SIZE * i;
    > - error = mxt_read_object_table(data->client, reg, buf);
    > - if (error)
    > - return error;
    > -
    > - object->type = buf[0];
    > - object->start_address = (buf[2] << 8) | buf[1];
    > - object->size = buf[3];
    > - object->instances = buf[4];
    > - object->num_report_ids = buf[5];
    > + le16_to_cpus(&object->start_address);
    >
    > if (object->num_report_ids) {
    > + min_id = reportid;
    > reportid += object->num_report_ids *
    > (object->instances + 1);
    > - object->max_reportid = reportid;
    > + max_id = reportid - 1;
    > + } else {
    > + min_id = 0;
    > + max_id = 0;
    > + }
    > +
    > + dev_info(&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);

    On a normal boot, how many lines of output does this driver generate?

    > +
    > + switch (object->type) {
    > + case MXT_TOUCH_MULTI_T9:
    > + data->T9_reportid_min = min_id;
    > + data->T9_reportid_max = max_id;
    > + break;
    > }
    > }
    >
    > @@ -995,8 +1002,11 @@ static ssize_t mxt_update_fw_store(struct device *dev,
    > /* Wait for reset */
    > msleep(MXT_FWRESET_TIME);
    >
    > + /* Destroy old object table and any cached fields */
    > kfree(data->object_table);
    > data->object_table = NULL;
    > + data->T9_reportid_min = 0;
    > + data->T9_reportid_max = 0;
    >
    > mxt_initialize(data);
    > }
    > --
    > 1.7.7.3
    >

    Thanks,
    Henrik


    \
     
     \ /
      Last update: 2012-06-27 22:01    [W:0.037 / U:30.184 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site