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linux-next/drivers/thermal/armada_thermal.c
Nadav Haklai b56100db5b thermal: armada: Fix possible overflow in the Armada 380 thermal sensor formula
Update the coefficients so the calculation will not overrun the
unsigned long 32bits boundary

Signed-off-by: Nadav Haklai <nadavh@marvell.com>
Reviewed-by: Victor Axelrod <victora@marvell.com>
Reviewed-by: Neta Zur Hershkovits <neta@marvell.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
2015-10-30 11:33:23 -07:00

321 lines
7.9 KiB
C

/*
* Marvell Armada 370/XP thermal sensor driver
*
* Copyright (C) 2013 Marvell
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/of_device.h>
#include <linux/thermal.h>
#define THERMAL_VALID_MASK 0x1
/* Thermal Manager Control and Status Register */
#define PMU_TDC0_SW_RST_MASK (0x1 << 1)
#define PMU_TM_DISABLE_OFFS 0
#define PMU_TM_DISABLE_MASK (0x1 << PMU_TM_DISABLE_OFFS)
#define PMU_TDC0_REF_CAL_CNT_OFFS 11
#define PMU_TDC0_REF_CAL_CNT_MASK (0x1ff << PMU_TDC0_REF_CAL_CNT_OFFS)
#define PMU_TDC0_OTF_CAL_MASK (0x1 << 30)
#define PMU_TDC0_START_CAL_MASK (0x1 << 25)
#define A375_UNIT_CONTROL_SHIFT 27
#define A375_UNIT_CONTROL_MASK 0x7
#define A375_READOUT_INVERT BIT(15)
#define A375_HW_RESETn BIT(8)
#define A380_HW_RESET BIT(8)
struct armada_thermal_data;
/* Marvell EBU Thermal Sensor Dev Structure */
struct armada_thermal_priv {
void __iomem *sensor;
void __iomem *control;
struct armada_thermal_data *data;
};
struct armada_thermal_data {
/* Initialize the sensor */
void (*init_sensor)(struct platform_device *pdev,
struct armada_thermal_priv *);
/* Test for a valid sensor value (optional) */
bool (*is_valid)(struct armada_thermal_priv *);
/* Formula coeficients: temp = (b + m * reg) / div */
unsigned long coef_b;
unsigned long coef_m;
unsigned long coef_div;
bool inverted;
/* Register shift and mask to access the sensor temperature */
unsigned int temp_shift;
unsigned int temp_mask;
unsigned int is_valid_shift;
};
static void armadaxp_init_sensor(struct platform_device *pdev,
struct armada_thermal_priv *priv)
{
unsigned long reg;
reg = readl_relaxed(priv->control);
reg |= PMU_TDC0_OTF_CAL_MASK;
writel(reg, priv->control);
/* Reference calibration value */
reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
reg |= (0xf1 << PMU_TDC0_REF_CAL_CNT_OFFS);
writel(reg, priv->control);
/* Reset the sensor */
reg = readl_relaxed(priv->control);
writel((reg | PMU_TDC0_SW_RST_MASK), priv->control);
writel(reg, priv->control);
/* Enable the sensor */
reg = readl_relaxed(priv->sensor);
reg &= ~PMU_TM_DISABLE_MASK;
writel(reg, priv->sensor);
}
static void armada370_init_sensor(struct platform_device *pdev,
struct armada_thermal_priv *priv)
{
unsigned long reg;
reg = readl_relaxed(priv->control);
reg |= PMU_TDC0_OTF_CAL_MASK;
writel(reg, priv->control);
/* Reference calibration value */
reg &= ~PMU_TDC0_REF_CAL_CNT_MASK;
reg |= (0xf1 << PMU_TDC0_REF_CAL_CNT_OFFS);
writel(reg, priv->control);
reg &= ~PMU_TDC0_START_CAL_MASK;
writel(reg, priv->control);
mdelay(10);
}
static void armada375_init_sensor(struct platform_device *pdev,
struct armada_thermal_priv *priv)
{
unsigned long reg;
reg = readl(priv->control + 4);
reg &= ~(A375_UNIT_CONTROL_MASK << A375_UNIT_CONTROL_SHIFT);
reg &= ~A375_READOUT_INVERT;
reg &= ~A375_HW_RESETn;
writel(reg, priv->control + 4);
mdelay(20);
reg |= A375_HW_RESETn;
writel(reg, priv->control + 4);
mdelay(50);
}
static void armada380_init_sensor(struct platform_device *pdev,
struct armada_thermal_priv *priv)
{
unsigned long reg = readl_relaxed(priv->control);
/* Reset hardware once */
if (!(reg & A380_HW_RESET)) {
reg |= A380_HW_RESET;
writel(reg, priv->control);
mdelay(10);
}
}
static bool armada_is_valid(struct armada_thermal_priv *priv)
{
unsigned long reg = readl_relaxed(priv->sensor);
return (reg >> priv->data->is_valid_shift) & THERMAL_VALID_MASK;
}
static int armada_get_temp(struct thermal_zone_device *thermal,
int *temp)
{
struct armada_thermal_priv *priv = thermal->devdata;
unsigned long reg;
unsigned long m, b, div;
/* Valid check */
if (priv->data->is_valid && !priv->data->is_valid(priv)) {
dev_err(&thermal->device,
"Temperature sensor reading not valid\n");
return -EIO;
}
reg = readl_relaxed(priv->sensor);
reg = (reg >> priv->data->temp_shift) & priv->data->temp_mask;
/* Get formula coeficients */
b = priv->data->coef_b;
m = priv->data->coef_m;
div = priv->data->coef_div;
if (priv->data->inverted)
*temp = ((m * reg) - b) / div;
else
*temp = (b - (m * reg)) / div;
return 0;
}
static struct thermal_zone_device_ops ops = {
.get_temp = armada_get_temp,
};
static const struct armada_thermal_data armadaxp_data = {
.init_sensor = armadaxp_init_sensor,
.temp_shift = 10,
.temp_mask = 0x1ff,
.coef_b = 3153000000UL,
.coef_m = 10000000UL,
.coef_div = 13825,
};
static const struct armada_thermal_data armada370_data = {
.is_valid = armada_is_valid,
.init_sensor = armada370_init_sensor,
.is_valid_shift = 9,
.temp_shift = 10,
.temp_mask = 0x1ff,
.coef_b = 3153000000UL,
.coef_m = 10000000UL,
.coef_div = 13825,
};
static const struct armada_thermal_data armada375_data = {
.is_valid = armada_is_valid,
.init_sensor = armada375_init_sensor,
.is_valid_shift = 10,
.temp_shift = 0,
.temp_mask = 0x1ff,
.coef_b = 3171900000UL,
.coef_m = 10000000UL,
.coef_div = 13616,
};
static const struct armada_thermal_data armada380_data = {
.is_valid = armada_is_valid,
.init_sensor = armada380_init_sensor,
.is_valid_shift = 10,
.temp_shift = 0,
.temp_mask = 0x3ff,
.coef_b = 1172499100UL,
.coef_m = 2000096UL,
.coef_div = 4201,
.inverted = true,
};
static const struct of_device_id armada_thermal_id_table[] = {
{
.compatible = "marvell,armadaxp-thermal",
.data = &armadaxp_data,
},
{
.compatible = "marvell,armada370-thermal",
.data = &armada370_data,
},
{
.compatible = "marvell,armada375-thermal",
.data = &armada375_data,
},
{
.compatible = "marvell,armada380-thermal",
.data = &armada380_data,
},
{
/* sentinel */
},
};
MODULE_DEVICE_TABLE(of, armada_thermal_id_table);
static int armada_thermal_probe(struct platform_device *pdev)
{
struct thermal_zone_device *thermal;
const struct of_device_id *match;
struct armada_thermal_priv *priv;
struct resource *res;
match = of_match_device(armada_thermal_id_table, &pdev->dev);
if (!match)
return -ENODEV;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->sensor = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(priv->sensor))
return PTR_ERR(priv->sensor);
res = platform_get_resource(pdev, IORESOURCE_MEM, 1);
priv->control = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(priv->control))
return PTR_ERR(priv->control);
priv->data = (struct armada_thermal_data *)match->data;
priv->data->init_sensor(pdev, priv);
thermal = thermal_zone_device_register("armada_thermal", 0, 0,
priv, &ops, NULL, 0, 0);
if (IS_ERR(thermal)) {
dev_err(&pdev->dev,
"Failed to register thermal zone device\n");
return PTR_ERR(thermal);
}
platform_set_drvdata(pdev, thermal);
return 0;
}
static int armada_thermal_exit(struct platform_device *pdev)
{
struct thermal_zone_device *armada_thermal =
platform_get_drvdata(pdev);
thermal_zone_device_unregister(armada_thermal);
return 0;
}
static struct platform_driver armada_thermal_driver = {
.probe = armada_thermal_probe,
.remove = armada_thermal_exit,
.driver = {
.name = "armada_thermal",
.of_match_table = armada_thermal_id_table,
},
};
module_platform_driver(armada_thermal_driver);
MODULE_AUTHOR("Ezequiel Garcia <ezequiel.garcia@free-electrons.com>");
MODULE_DESCRIPTION("Armada 370/XP thermal driver");
MODULE_LICENSE("GPL v2");