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/*
* Copyright (c) 2015, The Linux Foundation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/err.h>
#include <linux/io.h>
#include <linux/nvmem-consumer.h>
#include <linux/of_address.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include "tsens.h"
#define S0_ST_ADDR 0x1030
#define SN_ADDR_OFFSET 0x4
#define SN_ST_TEMP_MASK 0x3ff
#define CAL_DEGC_PT1 30
#define CAL_DEGC_PT2 120
#define SLOPE_FACTOR 1000
#define SLOPE_DEFAULT 3200
char *qfprom_read(struct device *dev, const char *cname)
{
struct nvmem_cell *cell;
ssize_t data;
char *ret;
cell = nvmem_cell_get(dev, cname);
if (IS_ERR(cell))
return ERR_CAST(cell);
ret = nvmem_cell_read(cell, &data);
nvmem_cell_put(cell);
return ret;
}
/*
* Use this function on devices where slope and offset calculations
* depend on calibration data read from qfprom. On others the slope
* and offset values are derived from tz->tzp->slope and tz->tzp->offset
* resp.
*/
void compute_intercept_slope(struct tsens_device *tmdev, u32 *p1,
u32 *p2, u32 mode)
{
int i;
int num, den;
for (i = 0; i < tmdev->num_sensors; i++) {
dev_dbg(tmdev->dev,
"sensor%d - data_point1:%#x data_point2:%#x\n",
i, p1[i], p2[i]);
tmdev->sensor[i].slope = SLOPE_DEFAULT;
if (mode == TWO_PT_CALIB) {
/*
* slope (m) = adc_code2 - adc_code1 (y2 - y1)/
* temp_120_degc - temp_30_degc (x2 - x1)
*/
num = p2[i] - p1[i];
num *= SLOPE_FACTOR;
den = CAL_DEGC_PT2 - CAL_DEGC_PT1;
tmdev->sensor[i].slope = num / den;
}
tmdev->sensor[i].offset = (p1[i] * SLOPE_FACTOR) -
(CAL_DEGC_PT1 *
tmdev->sensor[i].slope);
dev_dbg(tmdev->dev, "offset:%d\n", tmdev->sensor[i].offset);
}
}
static inline int code_to_degc(u32 adc_code, const struct tsens_sensor *s)
{
int degc, num, den;
num = (adc_code * SLOPE_FACTOR) - s->offset;
den = s->slope;
if (num > 0)
degc = num + (den / 2);
else if (num < 0)
degc = num - (den / 2);
else
degc = num;
degc /= den;
return degc;
}
int get_temp_common(struct tsens_device *tmdev, int id, int *temp)
{
struct tsens_sensor *s = &tmdev->sensor[id];
u32 code;
unsigned int status_reg;
int last_temp = 0, ret;
status_reg = S0_ST_ADDR + s->hw_id * SN_ADDR_OFFSET;
ret = regmap_read(tmdev->map, status_reg, &code);
if (ret)
return ret;
last_temp = code & SN_ST_TEMP_MASK;
*temp = code_to_degc(last_temp, s) * 1000;
return 0;
}
static const struct regmap_config tsens_config = {
.reg_bits = 32,
.val_bits = 32,
.reg_stride = 4,
};
int __init init_common(struct tsens_device *tmdev)
{
void __iomem *base;
struct resource *res;
struct platform_device *op = of_find_device_by_node(tmdev->dev->of_node);
if (!op)
return -EINVAL;
/* The driver only uses the TM register address space for now */
if (op->num_resources > 1) {
tmdev->tm_offset = 0;
} else {
/* old DTs where SROT and TM were in a contiguous 2K block */
tmdev->tm_offset = 0x1000;
}
res = platform_get_resource(op, IORESOURCE_MEM, 0);
base = devm_ioremap_resource(&op->dev, res);
if (IS_ERR(base))
return PTR_ERR(base);
tmdev->map = devm_regmap_init_mmio(tmdev->dev, base, &tsens_config);
if (IS_ERR(tmdev->map))
return PTR_ERR(tmdev->map);
return 0;
}
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