[PATCH RFC 2/8] Input: atmel_mxt_ts - add diagnostic data retrieval via debugfs

Nick Dyer
2015-12-02T20:53:41Z

Retrieve refs data from the T37 diagnostic data object and expose it via
a binary attribute in debugfs.

Signed-off-by: Nick Dyer <nick.dyer@itdev.co.uk>
---
drivers/input/touchscreen/atmel_mxt_ts.c | 212 +++++++++++++++++++++++++++++++
1 file changed, 212 insertions(+)

diff --git a/drivers/input/touchscreen/atmel_mxt_ts.c b/drivers/input/touchscreen/atmel_mxt_ts.c
index 4a1d218..a96fec4 100644
--- a/drivers/input/touchscreen/atmel_mxt_ts.c
+++ b/drivers/input/touchscreen/atmel_mxt_ts.c
@@ -28,6 +28,7 @@
#include <linux/of.h>
#include <linux/slab.h>
#include <asm/unaligned.h>
+#include <linux/debugfs.h>

/* Firmware files */
#define MXT_FW_NAME "maxtouch.fw"
@@ -124,6 +125,17 @@ struct t9_range {
#define MXT_COMMS_CTRL 0
#define MXT_COMMS_CMD 1

+/* MXT_DEBUG_DIAGNOSTIC_T37 */
+#define MXT_DIAGNOSTIC_PAGEUP 0x01
+#define MXT_DIAGNOSTIC_DELTAS 0x10
+#define MXT_DIAGNOSTIC_SIZE 128
+
+struct t37_debug {
+ u8 mode;
+ u8 page;
+ u8 data[MXT_DIAGNOSTIC_SIZE];
+};
+
/* Define for MXT_GEN_COMMAND_T6 */
#define MXT_BOOT_VALUE 0xa5
#define MXT_RESET_VALUE 0x01
@@ -205,6 +217,20 @@ struct mxt_object {
u8 num_report_ids;
} __packed;

+#ifdef CONFIG_DEBUG_FS
+struct mxt_dbg {
+ u16 t37_address;
+ u16 diag_cmd_address;
+ struct t37_debug *t37_buf;
+ u16 *debug_buf;
+ unsigned int t37_pages;
+ unsigned int t37_nodes;
+
+ struct dentry *debugfs_dir;
+ struct dentry *deltas_file;
+};
+#endif
+
/* Each client has this additional data */
struct mxt_data {
struct i2c_client *client;
@@ -233,6 +259,7 @@ struct mxt_data {
u8 num_touchids;
u8 multitouch;
struct t7_config t7_cfg;
+ struct mxt_dbg dbg;

/* Cached parameters from object table */
u16 T5_address;
@@ -2043,6 +2070,188 @@ recheck:
return 0;
}

+#ifdef CONFIG_DEBUG_FS
+static u16 mxt_get_debug_value(struct mxt_data *data, unsigned int x,
+ unsigned int y)
+{
+ struct mxt_dbg *dbg = &data->dbg;
+ unsigned int ofs, page;
+
+ ofs = (y + (x * (data->info.matrix_ysize))) * sizeof(u16);
+ page = ofs / MXT_DIAGNOSTIC_SIZE;
+ ofs %= MXT_DIAGNOSTIC_SIZE;
+
+ return get_unaligned_le16(&dbg->t37_buf[page].data[ofs]);
+}
+
+static void mxt_convert_debug_pages(struct mxt_data *data)
+{
+ struct mxt_dbg *dbg = &data->dbg;
+ unsigned int x = 0;
+ unsigned int y = 0;
+ unsigned int i;
+
+ for (i = 0; i < dbg->t37_nodes; i++) {
+ dbg->debug_buf[i] = mxt_get_debug_value(data, x, y);
+
+ /* Next value */
+ if (++x >= data->info.matrix_xsize) {
+ x = 0;
+ y++;
+ }
+ }
+}
+
+static int mxt_open_deltas(struct inode *inode, struct file *file)
+{
+ struct mxt_data *data = inode->i_private;
+ struct mxt_dbg *dbg = &data->dbg;
+ int retries = 0;
+ int page;
+ int ret;
+ u8 mode = MXT_DIAGNOSTIC_DELTAS;
+ u8 cmd = mode;
+ struct t37_debug *p;
+
+ for (page = 0; page < dbg->t37_pages; page++) {
+ p = dbg->t37_buf + page;
+
+ ret = mxt_write_reg(data->client, dbg->diag_cmd_address,
+ cmd);
+ if (ret)
+ return ret;
+
+ retries = 0;
+
+ /* Poll until command is actioned */
+ msleep(20);
+wait_cmd:
+ /* Read first two bytes only */
+ ret = __mxt_read_reg(data->client, dbg->t37_address,
+ 2, p);
+ if (ret)
+ return ret;
+
+ if ((p->mode != mode) || (p->page != page)) {
+ if (retries++ > 100)
+ return -EINVAL;
+
+ msleep(20);
+ goto wait_cmd;
+ }
+
+ /* Read entire T37 page */
+ ret = __mxt_read_reg(data->client, dbg->t37_address,
+ sizeof(struct t37_debug), p);
+ if (ret)
+ return ret;
+
+ dev_dbg(&data->client->dev, "%s page:%d retries:%d\n",
+ __func__, page, retries);
+
+ /* For remaining pages, write PAGEUP rather than mode */
+ cmd = MXT_DIAGNOSTIC_PAGEUP;
+ }
+
+ mxt_convert_debug_pages(data);
+ file->private_data = data;
+
+ return 0;
+}
+
+static ssize_t mxt_read_deltas(struct file *file, char __user *ubuf,
+ size_t count, loff_t *offp)
+{
+ struct mxt_data *data = file->private_data;
+
+ return simple_read_from_buffer(ubuf, count, offp,
+ data->dbg.debug_buf,
+ data->dbg.t37_nodes * sizeof(u16));
+}
+
+static const struct file_operations atmel_mxt_deltas_fops = {
+ .open = mxt_open_deltas,
+ .read = mxt_read_deltas,
+};
+
+static void mxt_debugfs_remove(struct mxt_data *data)
+{
+ debugfs_remove_recursive(data->dbg.debugfs_dir);
+}
+
+static void mxt_debugfs_init(struct mxt_data *data)
+{
+ struct mxt_dbg *dbg = &data->dbg;
+ struct mxt_object *object;
+ char dirname[50];
+
+ object = mxt_get_object(data, MXT_GEN_COMMAND_T6);
+ if (!object)
+ return;
+
+ dbg->diag_cmd_address = object->start_address + MXT_COMMAND_DIAGNOSTIC;
+
+ object = mxt_get_object(data, MXT_DEBUG_DIAGNOSTIC_T37);
+ if (!object)
+ return;
+
+ if (mxt_obj_size(object) != sizeof(struct t37_debug)) {
+ dev_warn(&data->client->dev, "Bad T37 size");
+ return;
+ }
+
+ dbg->t37_address = object->start_address;
+
+ snprintf(dirname, sizeof(dirname), "heatmap-%s-%s",
+ dev_driver_string(&data->client->dev),
+ dev_name(&data->client->dev));
+
+ dbg->debugfs_dir = debugfs_create_dir(dirname, NULL);
+ if (!dbg->debugfs_dir) {
+ dev_err(&data->client->dev, "Error creating debugfs dir\n");
+ return;
+ }
+
+ /* Calculate size of data and allocate buffer */
+ dbg->t37_nodes = data->info.matrix_xsize * data->info.matrix_ysize;
+ dbg->t37_pages = dbg->t37_nodes * sizeof(u16)
+ / sizeof(dbg->t37_buf->data) + 1;
+ dbg->debug_buf = devm_kzalloc(&data->client->dev,
+ dbg->t37_nodes * sizeof(u16),
+ GFP_KERNEL);
+ if (!dbg->debug_buf)
+ goto error;
+
+ dbg->t37_buf = devm_kzalloc(&data->client->dev,
+ sizeof(struct t37_debug) * dbg->t37_pages,
+ GFP_KERNEL);
+ if (!dbg->t37_buf)
+ goto error;
+
+ dbg->deltas_file = debugfs_create_file("deltas", S_IRUGO,
+ dbg->debugfs_dir, data,
+ &atmel_mxt_deltas_fops);
+ if (!dbg->deltas_file)
+ goto error;
+
+ dbg->deltas_file->d_inode->i_size = dbg->t37_nodes * sizeof(u16);
+
+ return;
+
+error:
+ dev_err(&data->client->dev, "Error creating debugfs entry\n");
+ mxt_debugfs_remove(data);
+}
+#else
+static inline void mxt_debugfs_remove(struct mxt_data *data)
+{
+}
+
+static inline void mxt_debugfs_init(struct mxt_data *data)
+{
+}
+#endif /* CONFIG_DEBUG_FS */
+
static int mxt_configure_objects(struct mxt_data *data,
const struct firmware *cfg)
{
@@ -2070,6 +2279,8 @@ static int mxt_configure_objects(struct mxt_data *data,
dev_warn(dev, "No touch object detected\n");
}

+ mxt_debugfs_init(data);
+
dev_info(dev,
"Family: %u Variant: %u Firmware V%u.%u.%02X Objects: %u\n",
info->family_id, info->variant_id, info->version >> 4,
@@ -2617,6 +2828,7 @@ static int mxt_remove(struct i2c_client *client)
{
struct mxt_data *data = i2c_get_clientdata(client);

+ mxt_debugfs_remove(data);
sysfs_remove_group(&client->dev.kobj, &mxt_attr_group);
free_irq(data->irq, data);
mxt_free_input_device(data);
--
2.5.0