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