drivers/input/serio/hp_sdc.c

Source file repositories/reference/linux-study-clean/drivers/input/serio/hp_sdc.c

File Facts

System
Linux kernel
Corpus path
drivers/input/serio/hp_sdc.c
Extension
.c
Size
29064 bytes
Lines
1129
Domain
Driver Families
Bucket
drivers/input
Inferred role
Driver Families: exported/initcall integration point
Status
integration implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

module_init(hp_sdc_register);
module_exit(hp_sdc_exit);

/* Timing notes:  These measurements taken on my 64MHz 7100-LC (715/64)
 *                                              cycles cycles-adj    time
 * between two consecutive mfctl(16)'s:              4        n/a    63ns
 * hp_sdc_spin_ibf when idle:                      119        115   1.7us
 * gsc_writeb status register:                      83         79   1.2us
 * IBF to clear after sending SET_IM:             6204       6006    93us
 * IBF to clear after sending LOAD_RT:            4467       4352    68us
 * IBF to clear after sending two LOAD_RTs:      18974      18859   295us
 * READ_T1, read status/data, IRQ, call handler: 35564        n/a   556us
 * cmd to ~IBF READ_T1 2nd time right after:   5158403        n/a    81ms
 * between IRQ received and ~IBF for above:    2578877        n/a    40ms
 *
 * Performance stats after a run of this module configuring HIL and
 * receiving a few mouse events:
 *
 * status in8  282508 cycles 7128 calls
 * status out8   8404 cycles  341 calls
 * data out8     1734 cycles   78 calls
 * isr         174324 cycles  617 calls (includes take)
 * take          1241 cycles    2 calls
 * put        1411504 cycles 6937 calls
 * task       1655209 cycles 6937 calls (includes put)
 *
 */

Annotation

Implementation Notes