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linux/drivers/thermal/rcar_gen3_thermal.c
Niklas Söderlund 63d23fb781 thermal/drivers/rcar_gen3: Update temperature approximation calculation 
The initial driver used a formula to approximate the temperature and
register values reversed engineered from an out-of-tree BSP driver. This
was needed as the datasheet at the time did not contain any information
on how to do this. Later Gen3 (Rev 2.30) and Gen4 (all) now contains
this information.

Update the approximation formula to use the datasheet's information
instead of the reversed-engineered one.

On an idle M3-N without fused calibration values for PTAT and THCODE the
old formula reports,

    zone0: 52000
    zone1: 53000
    zone2: 52500

While the new formula under the same circumstances reports,

    zone0: 52500
    zone1: 54000
    zone2: 54000

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20240327133013.3982199-3-niklas.soderlund+renesas@ragnatech.se
2024-04-23 12:40:29 +02:00

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// SPDX-License-Identifier: GPL-2.0
/*
* R-Car Gen3 THS thermal sensor driver
* Based on rcar_thermal.c and work from Hien Dang and Khiem Nguyen.
*
* Copyright (C) 2016 Renesas Electronics Corporation.
* Copyright (C) 2016 Sang Engineering
*/
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/thermal.h>
#include "thermal_hwmon.h"
/* Register offsets */
#define REG_GEN3_IRQSTR 0x04
#define REG_GEN3_IRQMSK 0x08
#define REG_GEN3_IRQCTL 0x0C
#define REG_GEN3_IRQEN 0x10
#define REG_GEN3_IRQTEMP1 0x14
#define REG_GEN3_IRQTEMP2 0x18
#define REG_GEN3_IRQTEMP3 0x1C
#define REG_GEN3_THCTR 0x20
#define REG_GEN3_TEMP 0x28
#define REG_GEN3_THCODE1 0x50
#define REG_GEN3_THCODE2 0x54
#define REG_GEN3_THCODE3 0x58
#define REG_GEN3_PTAT1 0x5c
#define REG_GEN3_PTAT2 0x60
#define REG_GEN3_PTAT3 0x64
#define REG_GEN3_THSCP 0x68
#define REG_GEN4_THSFMON00 0x180
#define REG_GEN4_THSFMON01 0x184
#define REG_GEN4_THSFMON02 0x188
#define REG_GEN4_THSFMON15 0x1BC
#define REG_GEN4_THSFMON16 0x1C0
#define REG_GEN4_THSFMON17 0x1C4
/* IRQ{STR,MSK,EN} bits */
#define IRQ_TEMP1 BIT(0)
#define IRQ_TEMP2 BIT(1)
#define IRQ_TEMP3 BIT(2)
#define IRQ_TEMPD1 BIT(3)
#define IRQ_TEMPD2 BIT(4)
#define IRQ_TEMPD3 BIT(5)
/* THCTR bits */
#define THCTR_PONM BIT(6)
#define THCTR_THSST BIT(0)
/* THSCP bits */
#define THSCP_COR_PARA_VLD (BIT(15) | BIT(14))
#define CTEMP_MASK 0xFFF
#define MCELSIUS(temp) ((temp) * 1000)
#define GEN3_FUSE_MASK 0xFFF
#define GEN4_FUSE_MASK 0xFFF
#define TSC_MAX_NUM 5
struct rcar_gen3_thermal_priv;
struct rcar_thermal_info {
int scale;
int adj_below;
int adj_above;
void (*read_fuses)(struct rcar_gen3_thermal_priv *priv);
};
struct equation_set_coef {
int a;
int b;
};
struct rcar_gen3_thermal_tsc {
struct rcar_gen3_thermal_priv *priv;
void __iomem *base;
struct thermal_zone_device *zone;
/* Different coefficients are used depending on a threshold. */
struct {
struct equation_set_coef below;
struct equation_set_coef above;
} coef;
int thcode[3];
};
struct rcar_gen3_thermal_priv {
struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM];
struct thermal_zone_device_ops ops;
unsigned int num_tscs;
int ptat[3];
int tj_t;
const struct rcar_thermal_info *info;
};
static inline u32 rcar_gen3_thermal_read(struct rcar_gen3_thermal_tsc *tsc,
u32 reg)
{
return ioread32(tsc->base + reg);
}
static inline void rcar_gen3_thermal_write(struct rcar_gen3_thermal_tsc *tsc,
u32 reg, u32 data)
{
iowrite32(data, tsc->base + reg);
}
/*
* Linear approximation for temperature
*
* [temp] = ((thadj - [reg]) * a) / b + adj
* [reg] = thadj - ([temp] - adj) * b / a
*
* The constants a and b are calculated using two triplets of int values PTAT
* and THCODE. PTAT and THCODE can either be read from hardware or use hard
* coded values from the driver. The formula to calculate a and b are taken from
* the datasheet. Different calculations are needed for a and b depending on
* if the input variables ([temp] or [reg]) are above or below a threshold. The
* threshold is also calculated from PTAT and THCODE using formulas from the
* datasheet.
*
* The constant thadj is one of the THCODE values, which one to use depends on
* the threshold and input value.
*
* The constants adj is taken verbatim from the datasheet. Two values exists,
* which one to use depends on the input value and the calculated threshold.
* Furthermore different SoC models supported by the driver have different sets
* of values. The values for each model are stored in the device match data.
*/
static void rcar_gen3_thermal_shared_coefs(struct rcar_gen3_thermal_priv *priv)
{
priv->tj_t =
DIV_ROUND_CLOSEST((priv->ptat[1] - priv->ptat[2]) * priv->info->scale,
priv->ptat[0] - priv->ptat[2])
+ priv->info->adj_below;
}
static void rcar_gen3_thermal_tsc_coefs(struct rcar_gen3_thermal_priv *priv,
struct rcar_gen3_thermal_tsc *tsc)
{
tsc->coef.below.a = priv->info->scale * (priv->ptat[2] - priv->ptat[1]);
tsc->coef.above.a = priv->info->scale * (priv->ptat[0] - priv->ptat[1]);
tsc->coef.below.b = (priv->ptat[2] - priv->ptat[0]) * (tsc->thcode[2] - tsc->thcode[1]);
tsc->coef.above.b = (priv->ptat[0] - priv->ptat[2]) * (tsc->thcode[1] - tsc->thcode[0]);
}
static int rcar_gen3_thermal_get_temp(struct thermal_zone_device *tz, int *temp)
{
struct rcar_gen3_thermal_tsc *tsc = thermal_zone_device_priv(tz);
struct rcar_gen3_thermal_priv *priv = tsc->priv;
const struct equation_set_coef *coef;
int adj, decicelsius, reg, thcode;
/* Read register and convert to mili Celsius */
reg = rcar_gen3_thermal_read(tsc, REG_GEN3_TEMP) & CTEMP_MASK;
if (reg < tsc->thcode[1]) {
adj = priv->info->adj_below;
coef = &tsc->coef.below;
thcode = tsc->thcode[2];
} else {
adj = priv->info->adj_above;
coef = &tsc->coef.above;
thcode = tsc->thcode[0];
}
/*
* The dividend can't be grown as it might overflow, instead shorten the
* divisor to convert to decidegree Celsius. If we convert after the
* division precision is lost as we will scale up from whole degrees
* Celsius.
*/
decicelsius = DIV_ROUND_CLOSEST(coef->a * (thcode - reg), coef->b / 10);
/* Guaranteed operating range is -40C to 125C. */
/* Reporting is done in millidegree Celsius */
*temp = decicelsius * 100 + adj * 1000;
return 0;
}
static int rcar_gen3_thermal_mcelsius_to_temp(struct rcar_gen3_thermal_tsc *tsc,
int mcelsius)
{
struct rcar_gen3_thermal_priv *priv = tsc->priv;
const struct equation_set_coef *coef;
int adj, celsius, thcode;
celsius = DIV_ROUND_CLOSEST(mcelsius, 1000);
if (celsius < priv->tj_t) {
coef = &tsc->coef.below;
adj = priv->info->adj_below;
thcode = tsc->thcode[2];
} else {
coef = &tsc->coef.above;
adj = priv->info->adj_above;
thcode = tsc->thcode[0];
}
return thcode - DIV_ROUND_CLOSEST((celsius - adj) * coef->b, coef->a);
}
static int rcar_gen3_thermal_set_trips(struct thermal_zone_device *tz, int low, int high)
{
struct rcar_gen3_thermal_tsc *tsc = thermal_zone_device_priv(tz);
u32 irqmsk = 0;
if (low != -INT_MAX) {
irqmsk |= IRQ_TEMPD1;
rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP1,
rcar_gen3_thermal_mcelsius_to_temp(tsc, low));
}
if (high != INT_MAX) {
irqmsk |= IRQ_TEMP2;
rcar_gen3_thermal_write(tsc, REG_GEN3_IRQTEMP2,
rcar_gen3_thermal_mcelsius_to_temp(tsc, high));
}
rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, irqmsk);
return 0;
}
static const struct thermal_zone_device_ops rcar_gen3_tz_of_ops = {
.get_temp = rcar_gen3_thermal_get_temp,
.set_trips = rcar_gen3_thermal_set_trips,
};
static irqreturn_t rcar_gen3_thermal_irq(int irq, void *data)
{
struct rcar_gen3_thermal_priv *priv = data;
unsigned int i;
u32 status;
for (i = 0; i < priv->num_tscs; i++) {
status = rcar_gen3_thermal_read(priv->tscs[i], REG_GEN3_IRQSTR);
rcar_gen3_thermal_write(priv->tscs[i], REG_GEN3_IRQSTR, 0);
if (status && priv->tscs[i]->zone)
thermal_zone_device_update(priv->tscs[i]->zone,
THERMAL_EVENT_UNSPECIFIED);
}
return IRQ_HANDLED;
}
static void rcar_gen3_thermal_read_fuses_gen3(struct rcar_gen3_thermal_priv *priv)
{
unsigned int i;
/*
* Set the pseudo calibration points with fused values.
* PTAT is shared between all TSCs but only fused for the first
* TSC while THCODEs are fused for each TSC.
*/
priv->ptat[0] = rcar_gen3_thermal_read(priv->tscs[0], REG_GEN3_PTAT1) &
GEN3_FUSE_MASK;
priv->ptat[1] = rcar_gen3_thermal_read(priv->tscs[0], REG_GEN3_PTAT2) &
GEN3_FUSE_MASK;
priv->ptat[2] = rcar_gen3_thermal_read(priv->tscs[0], REG_GEN3_PTAT3) &
GEN3_FUSE_MASK;
for (i = 0; i < priv->num_tscs; i++) {
struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
tsc->thcode[0] = rcar_gen3_thermal_read(tsc, REG_GEN3_THCODE1) &
GEN3_FUSE_MASK;
tsc->thcode[1] = rcar_gen3_thermal_read(tsc, REG_GEN3_THCODE2) &
GEN3_FUSE_MASK;
tsc->thcode[2] = rcar_gen3_thermal_read(tsc, REG_GEN3_THCODE3) &
GEN3_FUSE_MASK;
}
}
static void rcar_gen3_thermal_read_fuses_gen4(struct rcar_gen3_thermal_priv *priv)
{
unsigned int i;
/*
* Set the pseudo calibration points with fused values.
* PTAT is shared between all TSCs but only fused for the first
* TSC while THCODEs are fused for each TSC.
*/
priv->ptat[0] = rcar_gen3_thermal_read(priv->tscs[0], REG_GEN4_THSFMON16) &
GEN4_FUSE_MASK;
priv->ptat[1] = rcar_gen3_thermal_read(priv->tscs[0], REG_GEN4_THSFMON17) &
GEN4_FUSE_MASK;
priv->ptat[2] = rcar_gen3_thermal_read(priv->tscs[0], REG_GEN4_THSFMON15) &
GEN4_FUSE_MASK;
for (i = 0; i < priv->num_tscs; i++) {
struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
tsc->thcode[0] = rcar_gen3_thermal_read(tsc, REG_GEN4_THSFMON01) &
GEN4_FUSE_MASK;
tsc->thcode[1] = rcar_gen3_thermal_read(tsc, REG_GEN4_THSFMON02) &
GEN4_FUSE_MASK;
tsc->thcode[2] = rcar_gen3_thermal_read(tsc, REG_GEN4_THSFMON00) &
GEN4_FUSE_MASK;
}
}
static bool rcar_gen3_thermal_read_fuses(struct rcar_gen3_thermal_priv *priv)
{
unsigned int i;
u32 thscp;
/* If fuses are not set, fallback to pseudo values. */
thscp = rcar_gen3_thermal_read(priv->tscs[0], REG_GEN3_THSCP);
if (!priv->info->read_fuses ||
(thscp & THSCP_COR_PARA_VLD) != THSCP_COR_PARA_VLD) {
/* Default THCODE values in case FUSEs are not set. */
static const int thcodes[TSC_MAX_NUM][3] = {
{ 3397, 2800, 2221 },
{ 3393, 2795, 2216 },
{ 3389, 2805, 2237 },
{ 3415, 2694, 2195 },
{ 3356, 2724, 2244 },
};
priv->ptat[0] = 2631;
priv->ptat[1] = 1509;
priv->ptat[2] = 435;
for (i = 0; i < priv->num_tscs; i++) {
struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
tsc->thcode[0] = thcodes[i][0];
tsc->thcode[1] = thcodes[i][1];
tsc->thcode[2] = thcodes[i][2];
}
return false;
}
priv->info->read_fuses(priv);
return true;
}
static void rcar_gen3_thermal_init(struct rcar_gen3_thermal_priv *priv,
struct rcar_gen3_thermal_tsc *tsc)
{
u32 reg_val;
reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
reg_val &= ~THCTR_PONM;
rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
usleep_range(1000, 2000);
rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0);
rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
if (priv->ops.set_trips)
rcar_gen3_thermal_write(tsc, REG_GEN3_IRQEN,
IRQ_TEMPD1 | IRQ_TEMP2);
reg_val = rcar_gen3_thermal_read(tsc, REG_GEN3_THCTR);
reg_val |= THCTR_THSST;
rcar_gen3_thermal_write(tsc, REG_GEN3_THCTR, reg_val);
usleep_range(1000, 2000);
}
static const struct rcar_thermal_info rcar_m3w_thermal_info = {
.scale = 157,
.adj_below = -41,
.adj_above = 116,
.read_fuses = rcar_gen3_thermal_read_fuses_gen3,
};
static const struct rcar_thermal_info rcar_gen3_thermal_info = {
.scale = 167,
.adj_below = -41,
.adj_above = 126,
.read_fuses = rcar_gen3_thermal_read_fuses_gen3,
};
static const struct rcar_thermal_info rcar_gen4_thermal_info = {
.scale = 167,
.adj_below = -41,
.adj_above = 126,
.read_fuses = rcar_gen3_thermal_read_fuses_gen4,
};
static const struct of_device_id rcar_gen3_thermal_dt_ids[] = {
{
.compatible = "renesas,r8a774a1-thermal",
.data = &rcar_m3w_thermal_info,
},
{
.compatible = "renesas,r8a774b1-thermal",
.data = &rcar_gen3_thermal_info,
},
{
.compatible = "renesas,r8a774e1-thermal",
.data = &rcar_gen3_thermal_info,
},
{
.compatible = "renesas,r8a7795-thermal",
.data = &rcar_gen3_thermal_info,
},
{
.compatible = "renesas,r8a7796-thermal",
.data = &rcar_m3w_thermal_info,
},
{
.compatible = "renesas,r8a77961-thermal",
.data = &rcar_m3w_thermal_info,
},
{
.compatible = "renesas,r8a77965-thermal",
.data = &rcar_gen3_thermal_info,
},
{
.compatible = "renesas,r8a77980-thermal",
.data = &rcar_gen3_thermal_info,
},
{
.compatible = "renesas,r8a779a0-thermal",
.data = &rcar_gen3_thermal_info,
},
{
.compatible = "renesas,r8a779f0-thermal",
.data = &rcar_gen4_thermal_info,
},
{
.compatible = "renesas,r8a779g0-thermal",
.data = &rcar_gen4_thermal_info,
},
{
.compatible = "renesas,r8a779h0-thermal",
.data = &rcar_gen4_thermal_info,
},
{},
};
MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
static void rcar_gen3_thermal_remove(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
pm_runtime_put(dev);
pm_runtime_disable(dev);
}
static void rcar_gen3_hwmon_action(void *data)
{
struct thermal_zone_device *zone = data;
thermal_remove_hwmon_sysfs(zone);
}
static int rcar_gen3_thermal_request_irqs(struct rcar_gen3_thermal_priv *priv,
struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
unsigned int i;
char *irqname;
int ret, irq;
for (i = 0; i < 2; i++) {
irq = platform_get_irq_optional(pdev, i);
if (irq < 0)
return irq;
irqname = devm_kasprintf(dev, GFP_KERNEL, "%s:ch%d",
dev_name(dev), i);
if (!irqname)
return -ENOMEM;
ret = devm_request_threaded_irq(dev, irq, NULL,
rcar_gen3_thermal_irq,
IRQF_ONESHOT, irqname, priv);
if (ret)
return ret;
}
return 0;
}
static int rcar_gen3_thermal_probe(struct platform_device *pdev)
{
struct rcar_gen3_thermal_priv *priv;
struct device *dev = &pdev->dev;
struct resource *res;
struct thermal_zone_device *zone;
unsigned int i;
int ret;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->ops = rcar_gen3_tz_of_ops;
priv->info = of_device_get_match_data(dev);
platform_set_drvdata(pdev, priv);
if (rcar_gen3_thermal_request_irqs(priv, pdev))
priv->ops.set_trips = NULL;
pm_runtime_enable(dev);
pm_runtime_get_sync(dev);
for (i = 0; i < TSC_MAX_NUM; i++) {
struct rcar_gen3_thermal_tsc *tsc;
res = platform_get_resource(pdev, IORESOURCE_MEM, i);
if (!res)
break;
tsc = devm_kzalloc(dev, sizeof(*tsc), GFP_KERNEL);
if (!tsc) {
ret = -ENOMEM;
goto error_unregister;
}
tsc->priv = priv;
tsc->base = devm_ioremap_resource(dev, res);
if (IS_ERR(tsc->base)) {
ret = PTR_ERR(tsc->base);
goto error_unregister;
}
priv->tscs[i] = tsc;
}
priv->num_tscs = i;
if (!rcar_gen3_thermal_read_fuses(priv))
dev_info(dev, "No calibration values fused, fallback to driver values\n");
rcar_gen3_thermal_shared_coefs(priv);
for (i = 0; i < priv->num_tscs; i++) {
struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
rcar_gen3_thermal_init(priv, tsc);
rcar_gen3_thermal_tsc_coefs(priv, tsc);
zone = devm_thermal_of_zone_register(dev, i, tsc, &priv->ops);
if (IS_ERR(zone)) {
dev_err(dev, "Sensor %u: Can't register thermal zone\n", i);
ret = PTR_ERR(zone);
goto error_unregister;
}
tsc->zone = zone;
ret = thermal_add_hwmon_sysfs(tsc->zone);
if (ret)
goto error_unregister;
ret = devm_add_action_or_reset(dev, rcar_gen3_hwmon_action, zone);
if (ret)
goto error_unregister;
ret = thermal_zone_get_num_trips(tsc->zone);
if (ret < 0)
goto error_unregister;
dev_info(dev, "Sensor %u: Loaded %d trip points\n", i, ret);
}
if (!priv->num_tscs) {
ret = -ENODEV;
goto error_unregister;
}
return 0;
error_unregister:
rcar_gen3_thermal_remove(pdev);
return ret;
}
static int __maybe_unused rcar_gen3_thermal_resume(struct device *dev)
{
struct rcar_gen3_thermal_priv *priv = dev_get_drvdata(dev);
unsigned int i;
for (i = 0; i < priv->num_tscs; i++) {
struct rcar_gen3_thermal_tsc *tsc = priv->tscs[i];
rcar_gen3_thermal_init(priv, tsc);
}
return 0;
}
static SIMPLE_DEV_PM_OPS(rcar_gen3_thermal_pm_ops, NULL,
rcar_gen3_thermal_resume);
static struct platform_driver rcar_gen3_thermal_driver = {
.driver = {
.name = "rcar_gen3_thermal",
.pm = &rcar_gen3_thermal_pm_ops,
.of_match_table = rcar_gen3_thermal_dt_ids,
},
.probe = rcar_gen3_thermal_probe,
.remove_new = rcar_gen3_thermal_remove,
};
module_platform_driver(rcar_gen3_thermal_driver);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("R-Car Gen3 THS thermal sensor driver");
MODULE_AUTHOR("Wolfram Sang <wsa+renesas@sang-engineering.com>");
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