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/*
* Broadcom STB AVS TMON thermal sensor driver
*
* Copyright (c) 2015-2017 Broadcom
*
* 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.
*
*/
#define DRV_NAME "brcmstb_thermal"
#define pr_fmt(fmt) DRV_NAME ": " fmt
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/irqreturn.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/of_device.h>
#include <linux/thermal.h>
#define AVS_TMON_STATUS 0x00
#define AVS_TMON_STATUS_valid_msk BIT(11)
#define AVS_TMON_STATUS_data_msk GENMASK(10, 1)
#define AVS_TMON_STATUS_data_shift 1
#define AVS_TMON_EN_OVERTEMP_RESET 0x04
#define AVS_TMON_EN_OVERTEMP_RESET_msk BIT(0)
#define AVS_TMON_RESET_THRESH 0x08
#define AVS_TMON_RESET_THRESH_msk GENMASK(10, 1)
#define AVS_TMON_RESET_THRESH_shift 1
#define AVS_TMON_INT_IDLE_TIME 0x10
#define AVS_TMON_EN_TEMP_INT_SRCS 0x14
#define AVS_TMON_EN_TEMP_INT_SRCS_high BIT(1)
#define AVS_TMON_EN_TEMP_INT_SRCS_low BIT(0)
#define AVS_TMON_INT_THRESH 0x18
#define AVS_TMON_INT_THRESH_high_msk GENMASK(26, 17)
#define AVS_TMON_INT_THRESH_high_shift 17
#define AVS_TMON_INT_THRESH_low_msk GENMASK(10, 1)
#define AVS_TMON_INT_THRESH_low_shift 1
#define AVS_TMON_TEMP_INT_CODE 0x1c
#define AVS_TMON_TP_TEST_ENABLE 0x20
/* Default coefficients */
#define AVS_TMON_TEMP_SLOPE -487
#define AVS_TMON_TEMP_OFFSET 410040
/* HW related temperature constants */
#define AVS_TMON_TEMP_MAX 0x3ff
#define AVS_TMON_TEMP_MIN -88161
#define AVS_TMON_TEMP_MASK AVS_TMON_TEMP_MAX
enum avs_tmon_trip_type {
TMON_TRIP_TYPE_LOW = 0,
TMON_TRIP_TYPE_HIGH,
TMON_TRIP_TYPE_RESET,
TMON_TRIP_TYPE_MAX,
};
struct avs_tmon_trip {
/* HW bit to enable the trip */
u32 enable_offs;
u32 enable_mask;
/* HW field to read the trip temperature */
u32 reg_offs;
u32 reg_msk;
int reg_shift;
};
static struct avs_tmon_trip avs_tmon_trips[] = {
/* Trips when temperature is below threshold */
[TMON_TRIP_TYPE_LOW] = {
.enable_offs = AVS_TMON_EN_TEMP_INT_SRCS,
.enable_mask = AVS_TMON_EN_TEMP_INT_SRCS_low,
.reg_offs = AVS_TMON_INT_THRESH,
.reg_msk = AVS_TMON_INT_THRESH_low_msk,
.reg_shift = AVS_TMON_INT_THRESH_low_shift,
},
/* Trips when temperature is above threshold */
[TMON_TRIP_TYPE_HIGH] = {
.enable_offs = AVS_TMON_EN_TEMP_INT_SRCS,
.enable_mask = AVS_TMON_EN_TEMP_INT_SRCS_high,
.reg_offs = AVS_TMON_INT_THRESH,
.reg_msk = AVS_TMON_INT_THRESH_high_msk,
.reg_shift = AVS_TMON_INT_THRESH_high_shift,
},
/* Automatically resets chip when above threshold */
[TMON_TRIP_TYPE_RESET] = {
.enable_offs = AVS_TMON_EN_OVERTEMP_RESET,
.enable_mask = AVS_TMON_EN_OVERTEMP_RESET_msk,
.reg_offs = AVS_TMON_RESET_THRESH,
.reg_msk = AVS_TMON_RESET_THRESH_msk,
.reg_shift = AVS_TMON_RESET_THRESH_shift,
},
};
struct brcmstb_thermal_priv {
void __iomem *tmon_base;
struct device *dev;
struct thermal_zone_device *thermal;
};
static void avs_tmon_get_coeffs(struct thermal_zone_device *tz, int *slope,
int *offset)
{
*slope = thermal_zone_get_slope(tz);
*offset = thermal_zone_get_offset(tz);
}
/* Convert a HW code to a temperature reading (millidegree celsius) */
static inline int avs_tmon_code_to_temp(struct thermal_zone_device *tz,
u32 code)
{
const int val = code & AVS_TMON_TEMP_MASK;
int slope, offset;
avs_tmon_get_coeffs(tz, &slope, &offset);
return slope * val + offset;
}
/*
* Convert a temperature value (millidegree celsius) to a HW code
*
* @temp: temperature to convert
* @low: if true, round toward the low side
*/
static inline u32 avs_tmon_temp_to_code(struct thermal_zone_device *tz,
int temp, bool low)
{
int slope, offset;
if (temp < AVS_TMON_TEMP_MIN)
return AVS_TMON_TEMP_MAX; /* Maximum code value */
avs_tmon_get_coeffs(tz, &slope, &offset);
if (temp >= offset)
return 0; /* Minimum code value */
if (low)
return (u32)(DIV_ROUND_UP(offset - temp, abs(slope)));
else
return (u32)((offset - temp) / abs(slope));
}
static int brcmstb_get_temp(void *data, int *temp)
{
struct brcmstb_thermal_priv *priv = data;
u32 val;
long t;
val = __raw_readl(priv->tmon_base + AVS_TMON_STATUS);
if (!(val & AVS_TMON_STATUS_valid_msk)) {
dev_err(priv->dev, "reading not valid\n");
return -EIO;
}
val = (val & AVS_TMON_STATUS_data_msk) >> AVS_TMON_STATUS_data_shift;
t = avs_tmon_code_to_temp(priv->thermal, val);
if (t < 0)
*temp = 0;
else
*temp = t;
return 0;
}
static void avs_tmon_trip_enable(struct brcmstb_thermal_priv *priv,
enum avs_tmon_trip_type type, int en)
{
struct avs_tmon_trip *trip = &avs_tmon_trips[type];
u32 val = __raw_readl(priv->tmon_base + trip->enable_offs);
dev_dbg(priv->dev, "%sable trip, type %d\n", en ? "en" : "dis", type);
if (en)
val |= trip->enable_mask;
else
val &= ~trip->enable_mask;
__raw_writel(val, priv->tmon_base + trip->enable_offs);
}
static int avs_tmon_get_trip_temp(struct brcmstb_thermal_priv *priv,
enum avs_tmon_trip_type type)
{
struct avs_tmon_trip *trip = &avs_tmon_trips[type];
u32 val = __raw_readl(priv->tmon_base + trip->reg_offs);
val &= trip->reg_msk;
val >>= trip->reg_shift;
return avs_tmon_code_to_temp(priv->thermal, val);
}
static void avs_tmon_set_trip_temp(struct brcmstb_thermal_priv *priv,
enum avs_tmon_trip_type type,
int temp)
{
struct avs_tmon_trip *trip = &avs_tmon_trips[type];
u32 val, orig;
dev_dbg(priv->dev, "set temp %d to %d\n", type, temp);
/* round toward low temp for the low interrupt */
val = avs_tmon_temp_to_code(priv->thermal, temp,
type == TMON_TRIP_TYPE_LOW);
val <<= trip->reg_shift;
val &= trip->reg_msk;
orig = __raw_readl(priv->tmon_base + trip->reg_offs);
orig &= ~trip->reg_msk;
orig |= val;
__raw_writel(orig, priv->tmon_base + trip->reg_offs);
}
static int avs_tmon_get_intr_temp(struct brcmstb_thermal_priv *priv)
{
u32 val;
val = __raw_readl(priv->tmon_base + AVS_TMON_TEMP_INT_CODE);
return avs_tmon_code_to_temp(priv->thermal, val);
}
static irqreturn_t brcmstb_tmon_irq_thread(int irq, void *data)
{
struct brcmstb_thermal_priv *priv = data;
int low, high, intr;
low = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_LOW);
high = avs_tmon_get_trip_temp(priv, TMON_TRIP_TYPE_HIGH);
intr = avs_tmon_get_intr_temp(priv);
dev_dbg(priv->dev, "low/intr/high: %d/%d/%d\n",
low, intr, high);
/* Disable high-temp until next threshold shift */
if (intr >= high)
avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
/* Disable low-temp until next threshold shift */
if (intr <= low)
avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
/*
* Notify using the interrupt temperature, in case the temperature
* changes before it can next be read out
*/
thermal_zone_device_update(priv->thermal, intr);
return IRQ_HANDLED;
}
static int brcmstb_set_trips(void *data, int low, int high)
{
struct brcmstb_thermal_priv *priv = data;
dev_dbg(priv->dev, "set trips %d <--> %d\n", low, high);
/*
* Disable low-temp if "low" is too small. As per thermal framework
* API, we use -INT_MAX rather than INT_MIN.
*/
if (low <= -INT_MAX) {
avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 0);
} else {
avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_LOW, low);
avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_LOW, 1);
}
/* Disable high-temp if "high" is too big. */
if (high == INT_MAX) {
avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 0);
} else {
avs_tmon_set_trip_temp(priv, TMON_TRIP_TYPE_HIGH, high);
avs_tmon_trip_enable(priv, TMON_TRIP_TYPE_HIGH, 1);
}
return 0;
}
static struct thermal_zone_of_device_ops of_ops = {
.get_temp = brcmstb_get_temp,
.set_trips = brcmstb_set_trips,
};
static const struct of_device_id brcmstb_thermal_id_table[] = {
{ .compatible = "brcm,avs-tmon" },
{},
};
MODULE_DEVICE_TABLE(of, brcmstb_thermal_id_table);
static int brcmstb_thermal_probe(struct platform_device *pdev)
{
struct thermal_zone_device *thermal;
struct brcmstb_thermal_priv *priv;
struct resource *res;
int irq, ret;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
priv->tmon_base = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(priv->tmon_base))
return PTR_ERR(priv->tmon_base);
priv->dev = &pdev->dev;
platform_set_drvdata(pdev, priv);
thermal = devm_thermal_zone_of_sensor_register(&pdev->dev, 0, priv,
&of_ops);
if (IS_ERR(thermal)) {
ret = PTR_ERR(thermal);
dev_err(&pdev->dev, "could not register sensor: %d\n", ret);
return ret;
}
priv->thermal = thermal;
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(&pdev->dev, "could not get IRQ\n");
return irq;
}
ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
brcmstb_tmon_irq_thread, IRQF_ONESHOT,
DRV_NAME, priv);
if (ret < 0) {
dev_err(&pdev->dev, "could not request IRQ: %d\n", ret);
return ret;
}
dev_info(&pdev->dev, "registered AVS TMON of-sensor driver\n");
return 0;
}
static struct platform_driver brcmstb_thermal_driver = {
.probe = brcmstb_thermal_probe,
.driver = {
.name = DRV_NAME,
.of_match_table = brcmstb_thermal_id_table,
},
};
module_platform_driver(brcmstb_thermal_driver);
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Brian Norris");
MODULE_DESCRIPTION("Broadcom STB AVS TMON thermal driver");
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