linux/drivers/thermal/rcar_gen3_thermal.c
Niklas Söderlund 1b57b9597c thermal: rcar_gen3_thermal: Do not use interrupts for normal operation
Remove the usage of interrupts for the normal temperature operation and
depend on the polling performed by the thermal core. This is done to
prepare to use the interrupts as they are intended to trigger once
specific trip points are passed and not to react to temperature changes
in the normal operational range.

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20201126220923.3107213-1-niklas.soderlund+renesas@ragnatech.se
2020-11-30 16:38:27 +01:00

423 lines
10 KiB
C

// 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_device.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/sys_soc.h>
#include <linux/thermal.h>
#include "thermal_core.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_CTSR 0x20
#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
/* 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)
/* CTSR bits */
#define CTSR_PONM BIT(8)
#define CTSR_AOUT BIT(7)
#define CTSR_THBGR BIT(5)
#define CTSR_VMEN BIT(4)
#define CTSR_VMST BIT(1)
#define CTSR_THSST BIT(0)
/* THCTR bits */
#define THCTR_PONM BIT(6)
#define THCTR_THSST BIT(0)
#define CTEMP_MASK 0xFFF
#define MCELSIUS(temp) ((temp) * 1000)
#define GEN3_FUSE_MASK 0xFFF
#define TSC_MAX_NUM 3
/* default THCODE values if FUSEs are missing */
static const int thcodes[TSC_MAX_NUM][3] = {
{ 3397, 2800, 2221 },
{ 3393, 2795, 2216 },
{ 3389, 2805, 2237 },
};
/* Structure for thermal temperature calculation */
struct equation_coefs {
int a1;
int b1;
int a2;
int b2;
};
struct rcar_gen3_thermal_tsc {
void __iomem *base;
struct thermal_zone_device *zone;
struct equation_coefs coef;
int tj_t;
int id; /* thermal channel id */
};
struct rcar_gen3_thermal_priv {
struct rcar_gen3_thermal_tsc *tscs[TSC_MAX_NUM];
unsigned int num_tscs;
void (*thermal_init)(struct rcar_gen3_thermal_tsc *tsc);
};
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
*
* [reg] = [temp] * a + b => [temp] = ([reg] - 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 driver. The formula to calculate a and b are taken from
* BSP and sparsely documented and understood.
*
* Examining the linear formula and the formula used to calculate constants a
* and b while knowing that the span for PTAT and THCODE values are between
* 0x000 and 0xfff the largest integer possible is 0xfff * 0xfff == 0xffe001.
* Integer also needs to be signed so that leaves 7 bits for binary
* fixed point scaling.
*/
#define FIXPT_SHIFT 7
#define FIXPT_INT(_x) ((_x) << FIXPT_SHIFT)
#define INT_FIXPT(_x) ((_x) >> FIXPT_SHIFT)
#define FIXPT_DIV(_a, _b) DIV_ROUND_CLOSEST(((_a) << FIXPT_SHIFT), (_b))
#define FIXPT_TO_MCELSIUS(_x) ((_x) * 1000 >> FIXPT_SHIFT)
#define RCAR3_THERMAL_GRAN 500 /* mili Celsius */
/* no idea where these constants come from */
#define TJ_3 -41
static void rcar_gen3_thermal_calc_coefs(struct rcar_gen3_thermal_tsc *tsc,
int *ptat, const int *thcode,
int ths_tj_1)
{
/* TODO: Find documentation and document constant calculation formula */
/*
* Division is not scaled in BSP and if scaled it might overflow
* the dividend (4095 * 4095 << 14 > INT_MAX) so keep it unscaled
*/
tsc->tj_t = (FIXPT_INT((ptat[1] - ptat[2]) * 157)
/ (ptat[0] - ptat[2])) + FIXPT_INT(TJ_3);
tsc->coef.a1 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[2]),
tsc->tj_t - FIXPT_INT(TJ_3));
tsc->coef.b1 = FIXPT_INT(thcode[2]) - tsc->coef.a1 * TJ_3;
tsc->coef.a2 = FIXPT_DIV(FIXPT_INT(thcode[1] - thcode[0]),
tsc->tj_t - FIXPT_INT(ths_tj_1));
tsc->coef.b2 = FIXPT_INT(thcode[0]) - tsc->coef.a2 * ths_tj_1;
}
static int rcar_gen3_thermal_round(int temp)
{
int result, round_offs;
round_offs = temp >= 0 ? RCAR3_THERMAL_GRAN / 2 :
-RCAR3_THERMAL_GRAN / 2;
result = (temp + round_offs) / RCAR3_THERMAL_GRAN;
return result * RCAR3_THERMAL_GRAN;
}
static int rcar_gen3_thermal_get_temp(void *devdata, int *temp)
{
struct rcar_gen3_thermal_tsc *tsc = devdata;
int mcelsius, val;
int reg;
/* Read register and convert to mili Celsius */
reg = rcar_gen3_thermal_read(tsc, REG_GEN3_TEMP) & CTEMP_MASK;
if (reg <= thcodes[tsc->id][1])
val = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b1,
tsc->coef.a1);
else
val = FIXPT_DIV(FIXPT_INT(reg) - tsc->coef.b2,
tsc->coef.a2);
mcelsius = FIXPT_TO_MCELSIUS(val);
/* Guaranteed operating range is -40C to 125C. */
/* Round value to device granularity setting */
*temp = rcar_gen3_thermal_round(mcelsius);
return 0;
}
static const struct thermal_zone_of_device_ops rcar_gen3_tz_of_ops = {
.get_temp = rcar_gen3_thermal_get_temp,
};
static const struct soc_device_attribute r8a7795es1[] = {
{ .soc_id = "r8a7795", .revision = "ES1.*" },
{ /* sentinel */ }
};
static void rcar_gen3_thermal_init_r8a7795es1(struct rcar_gen3_thermal_tsc *tsc)
{
rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_THBGR);
rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, 0x0);
usleep_range(1000, 2000);
rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR, CTSR_PONM);
rcar_gen3_thermal_write(tsc, REG_GEN3_IRQCTL, 0x3F);
rcar_gen3_thermal_write(tsc, REG_GEN3_IRQMSK, 0);
rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN);
usleep_range(100, 200);
rcar_gen3_thermal_write(tsc, REG_GEN3_CTSR,
CTSR_PONM | CTSR_AOUT | CTSR_THBGR | CTSR_VMEN |
CTSR_VMST | CTSR_THSST);
usleep_range(1000, 2000);
}
static void rcar_gen3_thermal_init(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);
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 int rcar_gen3_ths_tj_1 = 126;
static const int rcar_gen3_ths_tj_1_m3_w = 116;
static const struct of_device_id rcar_gen3_thermal_dt_ids[] = {
{
.compatible = "renesas,r8a774a1-thermal",
.data = &rcar_gen3_ths_tj_1_m3_w,
},
{
.compatible = "renesas,r8a774b1-thermal",
.data = &rcar_gen3_ths_tj_1,
},
{
.compatible = "renesas,r8a774e1-thermal",
.data = &rcar_gen3_ths_tj_1,
},
{
.compatible = "renesas,r8a7795-thermal",
.data = &rcar_gen3_ths_tj_1,
},
{
.compatible = "renesas,r8a7796-thermal",
.data = &rcar_gen3_ths_tj_1_m3_w,
},
{
.compatible = "renesas,r8a77961-thermal",
.data = &rcar_gen3_ths_tj_1_m3_w,
},
{
.compatible = "renesas,r8a77965-thermal",
.data = &rcar_gen3_ths_tj_1,
},
{
.compatible = "renesas,r8a77980-thermal",
.data = &rcar_gen3_ths_tj_1,
},
{},
};
MODULE_DEVICE_TABLE(of, rcar_gen3_thermal_dt_ids);
static int rcar_gen3_thermal_remove(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
pm_runtime_put(dev);
pm_runtime_disable(dev);
return 0;
}
static void rcar_gen3_hwmon_action(void *data)
{
struct thermal_zone_device *zone = data;
thermal_remove_hwmon_sysfs(zone);
}
static int rcar_gen3_thermal_probe(struct platform_device *pdev)
{
struct rcar_gen3_thermal_priv *priv;
struct device *dev = &pdev->dev;
const int *rcar_gen3_ths_tj_1 = of_device_get_match_data(dev);
struct resource *res;
struct thermal_zone_device *zone;
int ret, i;
/* default values if FUSEs are missing */
/* TODO: Read values from hardware on supported platforms */
int ptat[3] = { 2631, 1509, 435 };
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->thermal_init = rcar_gen3_thermal_init;
if (soc_device_match(r8a7795es1))
priv->thermal_init = rcar_gen3_thermal_init_r8a7795es1;
platform_set_drvdata(pdev, priv);
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->base = devm_ioremap_resource(dev, res);
if (IS_ERR(tsc->base)) {
ret = PTR_ERR(tsc->base);
goto error_unregister;
}
tsc->id = i;
priv->tscs[i] = tsc;
priv->thermal_init(tsc);
rcar_gen3_thermal_calc_coefs(tsc, ptat, thcodes[i],
*rcar_gen3_ths_tj_1);
zone = devm_thermal_zone_of_sensor_register(dev, i, tsc,
&rcar_gen3_tz_of_ops);
if (IS_ERR(zone)) {
dev_err(dev, "Can't register thermal zone\n");
ret = PTR_ERR(zone);
goto error_unregister;
}
tsc->zone = zone;
tsc->zone->tzp->no_hwmon = false;
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 = of_thermal_get_ntrips(tsc->zone);
if (ret < 0)
goto error_unregister;
dev_info(dev, "TSC%d: Loaded %d trip points\n", i, ret);
}
priv->num_tscs = i;
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];
priv->thermal_init(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 = 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>");