u-boot/drivers/thermal/imx_thermal.c
Tim Harvey be56de6f33 thermal: imx_thermal: increase critical temperature threshold
The CPU temperature grade from OTP is now used to define the critical
threshold at which point we busyloop until we are below, however this
threshold is still too low.

Instead of 20C below the max CPU temperature, change it to 5C defined now
by TEMPERATURE_HOT_DETLA for clarity. Rename 'passive' to 'critical'
as that better defines our use case here. Additionally change the output
of the busyloop message to show the max CPU temperature as well as current.

Before:
CPU Temperature is 101 C, too hot to boot, waiting...
CPU Temperature is 101 C, too hot to boot, waiting...

After:
CPU Temperature (101C) too close to max (105C) waiting...
CPU Temperature (101C) too close to max (105C) waiting...

Cc: Stefan Roese <sr@denx.de>
Cc: Eric Nelson <eric.nelson@boundarydevices.com>
Cc: Heiko Schocher <hs@denx.de>
Cc: Nikita Kiryanov <nikita@compulab.co.il>
Cc: Jon Nettleton <jon.nettleton@gmail.com>
Cc: Jason Liu <r64343@freescale.com>
Cc: Ye Li <b37916@freescale.com>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: Markus Niebel <Markus.Niebel@tq-group.com>
Cc: Peng Fan <b51431@freescale.com>
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
2015-05-26 14:21:25 +02:00

187 lines
5 KiB
C

/*
* (C) Copyright 2014 Freescale Semiconductor, Inc.
* Author: Nitin Garg <nitin.garg@freescale.com>
* Ye Li <Ye.Li@freescale.com>
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <config.h>
#include <common.h>
#include <div64.h>
#include <fuse.h>
#include <asm/io.h>
#include <asm/arch/clock.h>
#include <asm/arch/sys_proto.h>
#include <dm.h>
#include <errno.h>
#include <malloc.h>
#include <thermal.h>
#include <imx_thermal.h>
/* board will busyloop until this many degrees C below CPU max temperature */
#define TEMPERATURE_HOT_DELTA 5 /* CPU maxT - 5C */
#define FACTOR0 10000000
#define FACTOR1 15976
#define FACTOR2 4297157
#define MEASURE_FREQ 327
#define TEMPSENSE0_TEMP_CNT_SHIFT 8
#define TEMPSENSE0_TEMP_CNT_MASK (0xfff << TEMPSENSE0_TEMP_CNT_SHIFT)
#define TEMPSENSE0_FINISHED (1 << 2)
#define TEMPSENSE0_MEASURE_TEMP (1 << 1)
#define TEMPSENSE0_POWER_DOWN (1 << 0)
#define MISC0_REFTOP_SELBIASOFF (1 << 3)
#define TEMPSENSE1_MEASURE_FREQ 0xffff
struct thermal_data {
unsigned int fuse;
int critical;
int minc;
int maxc;
};
static int read_cpu_temperature(struct udevice *dev)
{
int temperature;
unsigned int reg, n_meas;
const struct imx_thermal_plat *pdata = dev_get_platdata(dev);
struct anatop_regs *anatop = (struct anatop_regs *)pdata->regs;
struct thermal_data *priv = dev_get_priv(dev);
u32 fuse = priv->fuse;
int t1, n1;
u32 c1, c2;
u64 temp64;
/*
* Sensor data layout:
* [31:20] - sensor value @ 25C
* We use universal formula now and only need sensor value @ 25C
* slope = 0.4297157 - (0.0015976 * 25C fuse)
*/
n1 = fuse >> 20;
t1 = 25; /* t1 always 25C */
/*
* Derived from linear interpolation:
* slope = 0.4297157 - (0.0015976 * 25C fuse)
* slope = (FACTOR2 - FACTOR1 * n1) / FACTOR0
* (Nmeas - n1) / (Tmeas - t1) = slope
* We want to reduce this down to the minimum computation necessary
* for each temperature read. Also, we want Tmeas in millicelsius
* and we don't want to lose precision from integer division. So...
* Tmeas = (Nmeas - n1) / slope + t1
* milli_Tmeas = 1000 * (Nmeas - n1) / slope + 1000 * t1
* milli_Tmeas = -1000 * (n1 - Nmeas) / slope + 1000 * t1
* Let constant c1 = (-1000 / slope)
* milli_Tmeas = (n1 - Nmeas) * c1 + 1000 * t1
* Let constant c2 = n1 *c1 + 1000 * t1
* milli_Tmeas = c2 - Nmeas * c1
*/
temp64 = FACTOR0;
temp64 *= 1000;
do_div(temp64, FACTOR1 * n1 - FACTOR2);
c1 = temp64;
c2 = n1 * c1 + 1000 * t1;
/*
* now we only use single measure, every time we read
* the temperature, we will power on/down anadig thermal
* module
*/
writel(TEMPSENSE0_POWER_DOWN, &anatop->tempsense0_clr);
writel(MISC0_REFTOP_SELBIASOFF, &anatop->ana_misc0_set);
/* setup measure freq */
reg = readl(&anatop->tempsense1);
reg &= ~TEMPSENSE1_MEASURE_FREQ;
reg |= MEASURE_FREQ;
writel(reg, &anatop->tempsense1);
/* start the measurement process */
writel(TEMPSENSE0_MEASURE_TEMP, &anatop->tempsense0_clr);
writel(TEMPSENSE0_FINISHED, &anatop->tempsense0_clr);
writel(TEMPSENSE0_MEASURE_TEMP, &anatop->tempsense0_set);
/* make sure that the latest temp is valid */
while ((readl(&anatop->tempsense0) &
TEMPSENSE0_FINISHED) == 0)
udelay(10000);
/* read temperature count */
reg = readl(&anatop->tempsense0);
n_meas = (reg & TEMPSENSE0_TEMP_CNT_MASK)
>> TEMPSENSE0_TEMP_CNT_SHIFT;
writel(TEMPSENSE0_FINISHED, &anatop->tempsense0_clr);
/* milli_Tmeas = c2 - Nmeas * c1 */
temperature = (c2 - n_meas * c1)/1000;
/* power down anatop thermal sensor */
writel(TEMPSENSE0_POWER_DOWN, &anatop->tempsense0_set);
writel(MISC0_REFTOP_SELBIASOFF, &anatop->ana_misc0_clr);
return temperature;
}
int imx_thermal_get_temp(struct udevice *dev, int *temp)
{
struct thermal_data *priv = dev_get_priv(dev);
int cpu_tmp = 0;
cpu_tmp = read_cpu_temperature(dev);
while (cpu_tmp > priv->minc && cpu_tmp < priv->maxc) {
if (cpu_tmp >= priv->critical) {
printf("CPU Temperature (%dC) too close to max (%dC)",
cpu_tmp, priv->maxc);
puts(" waiting...\n");
udelay(5000000);
cpu_tmp = read_cpu_temperature(dev);
} else {
break;
}
}
*temp = cpu_tmp;
return 0;
}
static const struct dm_thermal_ops imx_thermal_ops = {
.get_temp = imx_thermal_get_temp,
};
static int imx_thermal_probe(struct udevice *dev)
{
unsigned int fuse = ~0;
const struct imx_thermal_plat *pdata = dev_get_platdata(dev);
struct thermal_data *priv = dev_get_priv(dev);
/* Read Temperature calibration data fuse */
fuse_read(pdata->fuse_bank, pdata->fuse_word, &fuse);
/* Check for valid fuse */
if (fuse == 0 || fuse == ~0) {
printf("CPU: Thermal invalid data, fuse: 0x%x\n", fuse);
return -EPERM;
}
/* set critical cooling temp */
get_cpu_temp_grade(&priv->minc, &priv->maxc);
priv->critical = priv->maxc - TEMPERATURE_HOT_DELTA;
priv->fuse = fuse;
enable_thermal_clk();
return 0;
}
U_BOOT_DRIVER(imx_thermal) = {
.name = "imx_thermal",
.id = UCLASS_THERMAL,
.ops = &imx_thermal_ops,
.probe = imx_thermal_probe,
.priv_auto_alloc_size = sizeof(struct thermal_data),
.flags = DM_FLAG_PRE_RELOC,
};