diff options
| author | Nicholas Troast <ntroast@codeaurora.org> | 2017-07-06 07:43:13 -0700 |
|---|---|---|
| committer | Abhijeet Dharmapurikar <adharmap@codeaurora.org> | 2017-07-31 19:28:02 -0700 |
| commit | 175907d3d24005e8557dbff1808649cabbf9414a (patch) | |
| tree | b911fbae56e27d40b58cfb015015ed6b98ea27d3 | |
| parent | 3c21390e3c2f3c526f33ae0226307f4cc579d0fd (diff) | |
power: fg-util: add median filter for circular buffer
A median filter is useful for filtering out outliers. Add it.
Change-Id: I21f97a870c262e5fb3d33b8250a2bf074f519b58
Signed-off-by: Nicholas Troast <ntroast@codeaurora.org>
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
| -rw-r--r-- | drivers/power/supply/qcom/fg-core.h | 3 | ||||
| -rw-r--r-- | drivers/power/supply/qcom/fg-util.c | 34 |
2 files changed, 36 insertions, 1 deletions
diff --git a/drivers/power/supply/qcom/fg-core.h b/drivers/power/supply/qcom/fg-core.h index e137a373937d..719f09a7c372 100644 --- a/drivers/power/supply/qcom/fg-core.h +++ b/drivers/power/supply/qcom/fg-core.h @@ -311,7 +311,7 @@ struct fg_irq_info { }; struct fg_circ_buf { - int arr[20]; + int arr[10]; int size; int head; }; @@ -483,5 +483,6 @@ extern bool is_qnovo_en(struct fg_chip *chip); extern void fg_circ_buf_add(struct fg_circ_buf *, int); extern void fg_circ_buf_clr(struct fg_circ_buf *); extern int fg_circ_buf_avg(struct fg_circ_buf *, int *); +extern int fg_circ_buf_median(struct fg_circ_buf *, int *); extern int fg_lerp(const struct fg_pt *, size_t, s32, s32 *); #endif diff --git a/drivers/power/supply/qcom/fg-util.c b/drivers/power/supply/qcom/fg-util.c index 9635044e02a5..0cb1dea7113b 100644 --- a/drivers/power/supply/qcom/fg-util.c +++ b/drivers/power/supply/qcom/fg-util.c @@ -10,6 +10,7 @@ * GNU General Public License for more details. */ +#include <linux/sort.h> #include "fg-core.h" void fg_circ_buf_add(struct fg_circ_buf *buf, int val) @@ -39,6 +40,39 @@ int fg_circ_buf_avg(struct fg_circ_buf *buf, int *avg) return 0; } +static int cmp_int(const void *a, const void *b) +{ + return *(int *)a - *(int *)b; +} + +int fg_circ_buf_median(struct fg_circ_buf *buf, int *median) +{ + int *temp; + + if (buf->size == 0) + return -ENODATA; + + if (buf->size == 1) { + *median = buf->arr[0]; + return 0; + } + + temp = kmalloc_array(buf->size, sizeof(*temp), GFP_KERNEL); + if (!temp) + return -ENOMEM; + + memcpy(temp, buf->arr, buf->size * sizeof(*temp)); + sort(temp, buf->size, sizeof(*temp), cmp_int, NULL); + + if (buf->size % 2) + *median = temp[buf->size / 2]; + else + *median = (temp[buf->size / 2 - 1] + temp[buf->size / 2]) / 2; + + kfree(temp); + return 0; +} + int fg_lerp(const struct fg_pt *pts, size_t tablesize, s32 input, s32 *output) { int i; |