// SPDX-License-Identifier: GPL-2.0
/*
* TI Bandgap temperature sensor driver for J72XX SoC Family
*
* Copyright (C) 2021 Texas Instruments Incorporated - http://www.ti.com/
*/
#include <linux/math.h>
#include <linux/math64.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/err.h>
#include <linux/types.h>
#include <linux/io.h>
#include <linux/thermal.h>
#include <linux/of.h>
#include <linux/delay.h>
#include <linux/slab.h>
#define K3_VTM_DEVINFO_PWR0_OFFSET 0x4
#define K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK 0xf0
#define K3_VTM_TMPSENS0_CTRL_OFFSET 0x300
#define K3_VTM_MISC_CTRL_OFFSET 0xc
#define K3_VTM_TMPSENS_STAT_OFFSET 0x8
#define K3_VTM_ANYMAXT_OUTRG_ALERT_EN 0x1
#define K3_VTM_MISC_CTRL2_OFFSET 0x10
#define K3_VTM_TS_STAT_DTEMP_MASK 0x3ff
#define K3_VTM_MAX_NUM_TS 8
#define K3_VTM_TMPSENS_CTRL_SOC BIT(5)
#define K3_VTM_TMPSENS_CTRL_CLRZ BIT(6)
#define K3_VTM_TMPSENS_CTRL_CLKON_REQ BIT(7)
#define K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN BIT(11)
#define K3_VTM_CORRECTION_TEMP_CNT 3
#define MINUS40CREF 5
#define PLUS30CREF 253
#define PLUS125CREF 730
#define PLUS150CREF 940
#define TABLE_SIZE 1024
#define MAX_TEMP 123000
#define COOL_DOWN_TEMP 105000
#define FACTORS_REDUCTION 13
static int *derived_table;
static int compute_value(int index, const s64 *factors, int nr_factors,
int reduction)
{
s64 value = 0;
int i;
for (i = 0; i < nr_factors; i++)
value += factors[i] * int_pow(index, i);
return (int)div64_s64(value, int_pow(10, reduction));
}
static void init_table(int factors_size, int *table, const s64 *factors)
{
int i;
for (i = 0; i < TABLE_SIZE; i++)
table[i] = compute_value(i, factors, factors_size,
FACTORS_REDUCTION);
}
/**
* struct err_values - structure containing error/reference values
* @refs: reference error values for -40C, 30C, 125C & 150C
* @errs: Actual error values for -40C, 30C, 125C & 150C read from the efuse
*/
struct err_values {
int refs[4];
int errs[4];
};
static void create_table_segments(struct err_values *err_vals, int seg,
int *ref_table)
{
int m = 0, c, num, den, i, err, idx1, idx2, err1, err2, ref1, ref2;
if (seg == 0)
idx1 = 0;
else
idx1 = err_vals->refs[seg];
idx2 = err_vals->refs[seg + 1];
err1 = err_vals->errs[seg];
err2 = err_vals->errs[seg + 1];
ref1 = err_vals->refs[seg];
ref2 = err_vals->refs[seg + 1];
/*
* Calculate the slope with adc values read from the register
* as the y-axis param and err in adc value as x-axis param
*/
num = ref2 - ref1;
den = err2 - err1;
if (den)
m = num / den;
c = ref2 - m * err2;
/*
* Take care of divide by zero error if error values are same
* Or when the slope is 0
*/
if (den != 0 && m != 0) {
for (i = idx1; i <= idx2; i++) {
err = (i - c) / m;
if (((i + err) < 0) || ((i + err) >= TABLE_SIZE))
continue;
derived_table[i] = ref_table[i + err];
}
} else { /* Constant error take care of divide by zero */
for (i = idx1; i <= idx2; i++) {
if (((i + err1) < 0) || ((i + err1) >= TABLE_SIZE))
continue;
derived_table[i] = ref_table[i + err1];
}
}
}
static int prep_lookup_table(struct err_values *err_vals, int *ref_table)
{
int inc, i, seg;
/*
* Fill up the lookup table under 3 segments
* region -40C to +30C
* region +30C to +125C
* region +125C to +150C
*/
for (seg = 0; seg < 3; seg++)
create_table_segments(err_vals, seg, ref_table);
/* Get to the first valid temperature */
i = 0;
while (!derived_table[i])
i++;
/*
* Get to the last zero index and back fill the temperature for
* sake of continuity
*/
if (i) {
/* 300 milli celsius steps */
while (i--)
derived_table[i] = derived_table[i + 1] - 300;
}
/*
* Fill the last trailing 0s which are unfilled with increments of
* 100 milli celsius till 1023 code
*/
i = TABLE_SIZE - 1;
while (!derived_table[i])
i--;
i++;
inc = 1;
while (i < TABLE_SIZE) {
derived_table[i] = derived_table[i - 1] + inc * 100;
i++;
}
return 0;
}
struct k3_thermal_data;
struct k3_j72xx_bandgap {
struct device *dev;
void __iomem *base;
void __iomem *cfg2_base;
struct k3_thermal_data *ts_data[K3_VTM_MAX_NUM_TS];
int cnt;
};
/* common data structures */
struct k3_thermal_data {
struct k3_j72xx_bandgap *bgp;
u32 ctrl_offset;
u32 stat_offset;
};
static int two_cmp(int tmp, int mask)
{
tmp = ~(tmp);
tmp &= mask;
tmp += 1;
/* Return negative value */
return (0 - tmp);
}
static unsigned int vtm_get_best_value(unsigned int s0, unsigned int s1,
unsigned int s2)
{
int d01 = abs(s0 - s1);
int d02 = abs(s0 - s2);
int d12 = abs(s1 - s2);
if (d01 <= d02 && d01 <= d12)
return (s0 + s1) / 2;
if (d02 <= d01 && d02 <= d12)
return (s0 + s2) / 2;
return (s1 + s2) / 2;
}
static inline int k3_bgp_read_temp(struct k3_thermal_data *devdata,
int *temp)
{
struct k3_j72xx_bandgap *bgp;
unsigned int dtemp, s0, s1, s2;
bgp = devdata->bgp;
/*
* Errata is applicable for am654 pg 1.0 silicon/J7ES. There
* is a variation of the order for certain degree centigrade on AM654.
* Work around that by getting the average of two closest
* readings out of three readings everytime we want to
* report temperatures.
*
* Errata workaround.
*/
s0 = readl(bgp->base + devdata->stat_offset) &
K3_VTM_TS_STAT_DTEMP_MASK;
s1 = readl(bgp->base + devdata->stat_offset) &
K3_VTM_TS_STAT_DTEMP_MASK;
s2 = readl(bgp->base + devdata->stat_offset) &
K3_VTM_TS_STAT_DTEMP_MASK;
dtemp = vtm_get_best_value(s0, s1, s2);
if (dtemp < 0 || dtemp >= TABLE_SIZE)
return -EINVAL;
*temp = derived_table[dtemp];
return 0;
}
/* Get temperature callback function for thermal zone */
static int k3_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
{
return k3_bgp_read_temp(thermal_zone_device_priv(tz), temp);
}
static const struct thermal_zone_device_ops k3_of_thermal_ops = {
.get_temp = k3_thermal_get_temp,
};
static int k3_j72xx_bandgap_temp_to_adc_code(int temp)
{
int low = 0, high = TABLE_SIZE - 1, mid;
if (temp > 160000 || temp < -50000)
return -EINVAL;
/* Binary search to find the adc code */
while (low < (high - 1)) {
mid = (low + high) / 2;
if (temp <= derived_table[mid])
high = mid;
else
low = mid;
}
return mid;
}
static void get_efuse_values(int id, struct k3_thermal_data *data, int *err,
void __iomem *fuse_base)
{
int i, tmp, pow;
int ct_offsets[5][K3_VTM_CORRECTION_TEMP_CNT] = {
{ 0x0, 0x8, 0x4 },
{ 0x0, 0x8, 0x4 },
{ 0x0, -1, 0x4 },
{ 0x0, 0xC, -1 },
{ 0x0, 0xc, 0x8 }
};
int ct_bm[5][K3_VTM_CORRECTION_TEMP_CNT] = {
{ 0x3f, 0x1fe000, 0x1ff },
{ 0xfc0, 0x1fe000, 0x3fe00 },
{ 0x3f000, 0x7f800000, 0x7fc0000 },
{ 0xfc0000, 0x1fe0, 0x1f800000 },
{ 0x3f000000, 0x1fe000, 0x1ff0 }
};
for (i = 0; i < 3; i++) {
/* Extract the offset value using bit-mask */
if (ct_offsets[id][i] == -1 && i == 1) {
/* 25C offset Case of Sensor 2 split between 2 regs */
tmp = (readl(fuse_base + 0x8) & 0xE0000000) >> (29);
tmp |= ((readl(fuse_base + 0xC) & 0x1F) << 3);
pow = tmp & 0x80;
} else if (ct_offsets[id][i] == -1 && i == 2) {
/* 125C Case of Sensor 3 split between 2 regs */
tmp = (readl(fuse_base + 0x4) & 0xF8000000) >> (27);
tmp |= ((readl(fuse_base + 0x8) & 0xF) << 5);
pow = tmp & 0x100;
} else {
tmp = readl(fuse_base + ct_offsets[id][i]);
tmp &= ct_bm[id][i];
tmp = tmp >> __ffs(ct_bm[id][i]);
/* Obtain the sign bit pow*/
pow = ct_bm[id][i] >> __ffs(ct_bm[id][i]);
pow += 1;
pow /= 2;
}
/* Check for negative value */
if (tmp & pow) {
/* 2's complement value */
tmp = two_cmp(tmp, ct_bm[id][i] >> __ffs(ct_bm[id][i]));
}
err[i] = tmp;
}
/* Err value for 150C is set to 0 */
err[i] = 0;
}
static void print_look_up_table(struct device *dev, int *ref_table)
{
int i;
dev_dbg(dev, "The contents of derived array\n");
dev_dbg(dev, "Code Temperature\n");
for (i = 0; i < TABLE_SIZE; i++)
dev_dbg(dev, "%d %d %d\n", i, derived_table[i], ref_table[i]);
}
static void k3_j72xx_bandgap_init_hw(struct k3_j72xx_bandgap *bgp)
{
struct k3_thermal_data *data;
int id, high_max, low_temp;
u32 val;
for (id = 0; id < bgp->cnt; id++) {
data = bgp->ts_data[id];
val = readl(bgp->cfg2_base + data->ctrl_offset);
val |= (K3_VTM_TMPSENS_CTRL_MAXT_OUTRG_EN |
K3_VTM_TMPSENS_CTRL_SOC |
K3_VTM_TMPSENS_CTRL_CLRZ | BIT(4));
writel(val, bgp->cfg2_base + data->ctrl_offset);
}
/*
* Program TSHUT thresholds
* Step 1: set the thresholds to ~123C and 105C WKUP_VTM_MISC_CTRL2
* Step 2: WKUP_VTM_TMPSENS_CTRL_j set the MAXT_OUTRG_EN bit
* This is already taken care as per of init
* Step 3: WKUP_VTM_MISC_CTRL set the ANYMAXT_OUTRG_ALERT_EN bit
*/
high_max = k3_j72xx_bandgap_temp_to_adc_code(MAX_TEMP);
low_temp = k3_j72xx_bandgap_temp_to_adc_code(COOL_DOWN_TEMP);
writel((low_temp << 16) | high_max, bgp->cfg2_base + K3_VTM_MISC_CTRL2_OFFSET);
writel(K3_VTM_ANYMAXT_OUTRG_ALERT_EN, bgp->cfg2_base + K3_VTM_MISC_CTRL_OFFSET);
}
struct k3_j72xx_bandgap_data {
const bool has_errata_i2128;
};
static int k3_j72xx_bandgap_probe(struct platform_device *pdev)
{
const struct k3_j72xx_bandgap_data *driver_data;
struct thermal_zone_device *ti_thermal;
struct device *dev = &pdev->dev;
bool workaround_needed = false;
struct k3_j72xx_bandgap *bgp;
struct k3_thermal_data *data;
struct err_values err_vals;
void __iomem *fuse_base;
int ret = 0, val, id;
struct resource *res;
int *ref_table;
const s64 golden_factors[] = {
-490019999999999936,
3251200000000000,
-1705800000000,
603730000,
-92627,
};
const s64 pvt_wa_factors[] = {
-415230000000000000,
3126600000000000,
-1157800000000,
};
bgp = devm_kzalloc(&pdev->dev, sizeof(*bgp), GFP_KERNEL);
if (!bgp)
return -ENOMEM;
bgp->dev = dev;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
bgp->base = devm_ioremap_resource(dev, res);
if (IS_ERR(bgp->base))
return PTR_ERR(bgp->base);
res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
bgp->cfg2_base = devm_ioremap_resource(dev, res);
if (IS_ERR(bgp->cfg2_base))
return PTR_ERR(bgp->cfg2_base);
driver_data = of_device_get_match_data(dev);
if (driver_data)
workaround_needed = driver_data->has_errata_i2128;
/*
* Some of TI's J721E SoCs require a software trimming procedure
* for the temperature monitors to function properly. To determine
* if this particular SoC is NOT affected, both bits in the
* WKUP_SPARE_FUSE0[31:30] will be set (0xC0000000) indicating
* when software trimming should NOT be applied.
*
* https://www.ti.com/lit/er/sprz455c/sprz455c.pdf
*/
if (workaround_needed) {
res = platform_get_resource(pdev, IORESOURCE_MEM, 2);
fuse_base = devm_ioremap_resource(dev, res);
if (IS_ERR(fuse_base))
return PTR_ERR(fuse_base);
if ((readl(fuse_base) & 0xc0000000) == 0xc0000000)
workaround_needed = false;
}
dev_dbg(bgp->dev, "Work around %sneeded\n",
workaround_needed ? "" : "not ");
pm_runtime_enable(dev);
ret = pm_runtime_get_sync(dev);
if (ret < 0) {
pm_runtime_put_noidle(dev);
pm_runtime_disable(dev);
return ret;
}
/* Get the sensor count in the VTM */
val = readl(bgp->base + K3_VTM_DEVINFO_PWR0_OFFSET);
bgp->cnt = val & K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK;
bgp->cnt >>= __ffs(K3_VTM_DEVINFO_PWR0_TEMPSENS_CT_MASK);
data = devm_kcalloc(bgp->dev, bgp->cnt, sizeof(*data), GFP_KERNEL);
if (!data) {
ret = -ENOMEM;
goto err_alloc;
}
ref_table = kzalloc(sizeof(*ref_table) * TABLE_SIZE, GFP_KERNEL);
if (!ref_table) {
ret = -ENOMEM;
goto err_alloc;
}
derived_table = devm_kzalloc(bgp->dev, sizeof(*derived_table) * TABLE_SIZE,
GFP_KERNEL);
if (!derived_table) {
ret = -ENOMEM;
goto err_free_ref_table;
}
if (!workaround_needed)
init_table(5, ref_table, golden_factors);
else
init_table(3, ref_table, pvt_wa_factors);
/* Precompute the derived table & fill each thermal sensor struct */
for (id = 0; id < bgp->cnt; id++) {
data[id].bgp = bgp;
data[id].ctrl_offset = K3_VTM_TMPSENS0_CTRL_OFFSET + id * 0x20;
data[id].stat_offset = data[id].ctrl_offset +
K3_VTM_TMPSENS_STAT_OFFSET;
if (workaround_needed) {
/* ref adc values for -40C, 30C & 125C respectively */
err_vals.refs[0] = MINUS40CREF;
err_vals.refs[1] = PLUS30CREF;
err_vals.refs[2] = PLUS125CREF;
err_vals.refs[3] = PLUS150CREF;
get_efuse_values(id, &data[id], err_vals.errs, fuse_base);
}
if (id == 0 && workaround_needed)
prep_lookup_table(&err_vals, ref_table);
else if (id == 0 && !workaround_needed)
memcpy(derived_table, ref_table, TABLE_SIZE * 4);
bgp->ts_data[id] = &data[id];
}
k3_j72xx_bandgap_init_hw(bgp);
/* Register the thermal sensors */
for (id = 0; id < bgp->cnt; id++) {
ti_thermal = devm_thermal_of_zone_register(bgp->dev, id, &data[id],
&k3_of_thermal_ops);
if (IS_ERR(ti_thermal)) {
dev_err(bgp->dev, "thermal zone device is NULL\n");
ret = PTR_ERR(ti_thermal);
goto err_free_ref_table;
}
}
platform_set_drvdata(pdev, bgp);
print_look_up_table(dev, ref_table);
/*
* Now that the derived_table has the appropriate look up values
* Free up the ref_table
*/
kfree(ref_table);
return 0;
err_free_ref_table:
kfree(ref_table);
err_alloc:
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
return ret;
}
static void k3_j72xx_bandgap_remove(struct platform_device *pdev)
{
pm_runtime_put_sync(&pdev->dev);
pm_runtime_disable(&pdev->dev);
}
static int k3_j72xx_bandgap_suspend(struct device *dev)
{
pm_runtime_put_sync(dev);
pm_runtime_disable(dev);
return 0;
}
static int k3_j72xx_bandgap_resume(struct device *dev)
{
struct k3_j72xx_bandgap *bgp = dev_get_drvdata(dev);
int ret;
pm_runtime_enable(dev);
ret = pm_runtime_get_sync(dev);
if (ret < 0) {
pm_runtime_put_noidle(dev);
pm_runtime_disable(dev);
return ret;
}
k3_j72xx_bandgap_init_hw(bgp);
return 0;
}
static DEFINE_SIMPLE_DEV_PM_OPS(k3_j72xx_bandgap_pm_ops,
k3_j72xx_bandgap_suspend,
k3_j72xx_bandgap_resume);
static const struct k3_j72xx_bandgap_data k3_j72xx_bandgap_j721e_data = {
.has_errata_i2128 = true,
};
static const struct k3_j72xx_bandgap_data k3_j72xx_bandgap_j7200_data = {
.has_errata_i2128 = false,
};
static const struct of_device_id of_k3_j72xx_bandgap_match[] = {
{
.compatible = "ti,j721e-vtm",
.data = &k3_j72xx_bandgap_j721e_data,
},
{
.compatible = "ti,j7200-vtm",
.data = &k3_j72xx_bandgap_j7200_data,
},
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, of_k3_j72xx_bandgap_match);
static struct platform_driver k3_j72xx_bandgap_sensor_driver = {
.probe = k3_j72xx_bandgap_probe,
.remove_new = k3_j72xx_bandgap_remove,
.driver = {
.name = "k3-j72xx-soc-thermal",
.of_match_table = of_k3_j72xx_bandgap_match,
.pm = pm_sleep_ptr(&k3_j72xx_bandgap_pm_ops),
},
};
module_platform_driver(k3_j72xx_bandgap_sensor_driver);
MODULE_DESCRIPTION("K3 bandgap temperature sensor driver");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("J Keerthy <[email protected]>");
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