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Commit 175907d3 authored by Nicholas Troast's avatar Nicholas Troast Committed by Abhijeet Dharmapurikar
Browse files

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: default avatarNicholas Troast <ntroast@codeaurora.org>
Signed-off-by: default avatarAbhijeet Dharmapurikar <adharmap@codeaurora.org>
parent 3c21390e

drivers/power/supply/qcom/fg-core.h

+2 −1
Original line number Diff line number Diff line
@@ -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

drivers/power/supply/qcom/fg-util.c

+34 −0
Original line number Diff line number Diff line
@@ -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;