linux/drivers/thermal/tegra/soctherm-fuse.c

161 lines
4.8 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2014-2016, NVIDIA CORPORATION. All rights reserved.
*/
#include <linux/module.h>
#include <linux/platform_device.h>
#include <soc/tegra/fuse.h>
#include "soctherm.h"
#define NOMINAL_CALIB_FT 105
#define NOMINAL_CALIB_CP 25
#define FUSE_TSENSOR_CALIB_CP_TS_BASE_MASK 0x1fff
#define FUSE_TSENSOR_CALIB_FT_TS_BASE_MASK (0x1fff << 13)
#define FUSE_TSENSOR_CALIB_FT_TS_BASE_SHIFT 13
#define FUSE_TSENSOR_COMMON 0x180
/*
* Tegra210: Layout of bits in FUSE_TSENSOR_COMMON:
* 3 2 1 0
* 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* | BASE_FT | BASE_CP | SHFT_FT | SHIFT_CP |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* Tegra12x, etc:
* In chips prior to Tegra210, this fuse was incorrectly sized as 26 bits,
* and didn't hold SHIFT_CP in [31:26]. Therefore these missing six bits
* were obtained via the FUSE_SPARE_REALIGNMENT_REG register [5:0].
*
* FUSE_TSENSOR_COMMON:
* 3 2 1 0
* 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |-----------| SHFT_FT | BASE_FT | BASE_CP |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*
* FUSE_SPARE_REALIGNMENT_REG:
* 3 2 1 0
* 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
* |---------------------------------------------------| SHIFT_CP |
* +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
*/
#define CALIB_COEFFICIENT 1000000LL
/**
* div64_s64_precise() - wrapper for div64_s64()
* @a: the dividend
* @b: the divisor
*
* Implements division with fairly accurate rounding instead of truncation by
* shifting the dividend to the left by 16 so that the quotient has a
* much higher precision.
*
* Return: the quotient of a / b.
*/
static s64 div64_s64_precise(s64 a, s32 b)
{
s64 r, al;
/* Scale up for increased precision division */
al = a << 16;
r = div64_s64(al * 2 + 1, 2 * b);
return r >> 16;
}
int tegra_calc_shared_calib(const struct tegra_soctherm_fuse *tfuse,
struct tsensor_shared_calib *shared)
{
u32 val;
s32 shifted_cp, shifted_ft;
int err;
err = tegra_fuse_readl(FUSE_TSENSOR_COMMON, &val);
if (err)
return err;
shared->base_cp = (val & tfuse->fuse_base_cp_mask) >>
tfuse->fuse_base_cp_shift;
shared->base_ft = (val & tfuse->fuse_base_ft_mask) >>
tfuse->fuse_base_ft_shift;
shifted_ft = (val & tfuse->fuse_shift_ft_mask) >>
tfuse->fuse_shift_ft_shift;
shifted_ft = sign_extend32(shifted_ft, 4);
if (tfuse->fuse_spare_realignment) {
err = tegra_fuse_readl(tfuse->fuse_spare_realignment, &val);
if (err)
return err;
}
shifted_cp = sign_extend32(val, 5);
shared->actual_temp_cp = 2 * NOMINAL_CALIB_CP + shifted_cp;
shared->actual_temp_ft = 2 * NOMINAL_CALIB_FT + shifted_ft;
return 0;
}
int tegra_calc_tsensor_calib(const struct tegra_tsensor *sensor,
const struct tsensor_shared_calib *shared,
u32 *calibration)
{
const struct tegra_tsensor_group *sensor_group;
u32 val, calib;
s32 actual_tsensor_ft, actual_tsensor_cp;
s32 delta_sens, delta_temp;
s32 mult, div;
s16 therma, thermb;
s64 temp;
int err;
sensor_group = sensor->group;
err = tegra_fuse_readl(sensor->calib_fuse_offset, &val);
if (err)
return err;
actual_tsensor_cp = (shared->base_cp * 64) + sign_extend32(val, 12);
val = (val & FUSE_TSENSOR_CALIB_FT_TS_BASE_MASK) >>
FUSE_TSENSOR_CALIB_FT_TS_BASE_SHIFT;
actual_tsensor_ft = (shared->base_ft * 32) + sign_extend32(val, 12);
delta_sens = actual_tsensor_ft - actual_tsensor_cp;
delta_temp = shared->actual_temp_ft - shared->actual_temp_cp;
mult = sensor_group->pdiv * sensor->config->tsample_ate;
div = sensor->config->tsample * sensor_group->pdiv_ate;
temp = (s64)delta_temp * (1LL << 13) * mult;
therma = div64_s64_precise(temp, (s64)delta_sens * div);
temp = ((s64)actual_tsensor_ft * shared->actual_temp_cp) -
((s64)actual_tsensor_cp * shared->actual_temp_ft);
thermb = div64_s64_precise(temp, delta_sens);
temp = (s64)therma * sensor->fuse_corr_alpha;
therma = div64_s64_precise(temp, CALIB_COEFFICIENT);
temp = (s64)thermb * sensor->fuse_corr_alpha + sensor->fuse_corr_beta;
thermb = div64_s64_precise(temp, CALIB_COEFFICIENT);
calib = ((u16)therma << SENSOR_CONFIG2_THERMA_SHIFT) |
((u16)thermb << SENSOR_CONFIG2_THERMB_SHIFT);
*calibration = calib;
return 0;
}
MODULE_AUTHOR("Wei Ni <wni@nvidia.com>");
MODULE_DESCRIPTION("Tegra SOCTHERM fuse management");
MODULE_LICENSE("GPL v2");