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alistair23-linux/drivers/hwmon/jc42.c
Peter Rosin 68615eb01f hwmon: (jc42) optionally try to disable the SMBUS timeout 
With a nxp,se97 chip on an atmel sama5d31 board, the I2C adapter driver
is not always capable of avoiding the 25-35 ms timeout as specified by
the SMBUS protocol. This may cause silent corruption of the last bit of
any transfer, e.g. a one is read instead of a zero if the sensor chip
times out. This also affects the eeprom half of the nxp-se97 chip, where
this silent corruption was originally noticed. Other I2C adapters probably
suffer similar issues, e.g. bit-banging comes to mind as risky...

The SMBUS register in the nxp chip is not a standard Jedec register, but
it is not special to the nxp chips either, at least the atmel chips
have the same mechanism. Therefore, do not special case this on the
manufacturer, it is opt-in via the device property anyway.

Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: Peter Rosin <peda@axentia.se>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
2017-11-30 13:12:44 -08:00

617 lines
16 KiB
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/*
* jc42.c - driver for Jedec JC42.4 compliant temperature sensors
*
* Copyright (c) 2010 Ericsson AB.
*
* Derived from lm77.c by Andras BALI <drewie@freemail.hu>.
*
* JC42.4 compliant temperature sensors are typically used on memory modules.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/bitops.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/jiffies.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/err.h>
#include <linux/mutex.h>
#include <linux/of.h>
/* Addresses to scan */
static const unsigned short normal_i2c[] = {
0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, I2C_CLIENT_END };
/* JC42 registers. All registers are 16 bit. */
#define JC42_REG_CAP 0x00
#define JC42_REG_CONFIG 0x01
#define JC42_REG_TEMP_UPPER 0x02
#define JC42_REG_TEMP_LOWER 0x03
#define JC42_REG_TEMP_CRITICAL 0x04
#define JC42_REG_TEMP 0x05
#define JC42_REG_MANID 0x06
#define JC42_REG_DEVICEID 0x07
#define JC42_REG_SMBUS 0x22 /* NXP and Atmel, possibly others? */
/* Status bits in temperature register */
#define JC42_ALARM_CRIT_BIT 15
#define JC42_ALARM_MAX_BIT 14
#define JC42_ALARM_MIN_BIT 13
/* Configuration register defines */
#define JC42_CFG_CRIT_ONLY (1 << 2)
#define JC42_CFG_TCRIT_LOCK (1 << 6)
#define JC42_CFG_EVENT_LOCK (1 << 7)
#define JC42_CFG_SHUTDOWN (1 << 8)
#define JC42_CFG_HYST_SHIFT 9
#define JC42_CFG_HYST_MASK (0x03 << 9)
/* Capabilities */
#define JC42_CAP_RANGE (1 << 2)
/* Manufacturer IDs */
#define ADT_MANID 0x11d4 /* Analog Devices */
#define ATMEL_MANID 0x001f /* Atmel */
#define ATMEL_MANID2 0x1114 /* Atmel */
#define MAX_MANID 0x004d /* Maxim */
#define IDT_MANID 0x00b3 /* IDT */
#define MCP_MANID 0x0054 /* Microchip */
#define NXP_MANID 0x1131 /* NXP Semiconductors */
#define ONS_MANID 0x1b09 /* ON Semiconductor */
#define STM_MANID 0x104a /* ST Microelectronics */
#define GT_MANID 0x1c68 /* Giantec */
#define GT_MANID2 0x132d /* Giantec, 2nd mfg ID */
/* SMBUS register */
#define SMBUS_STMOUT BIT(7) /* SMBus time-out, active low */
/* Supported chips */
/* Analog Devices */
#define ADT7408_DEVID 0x0801
#define ADT7408_DEVID_MASK 0xffff
/* Atmel */
#define AT30TS00_DEVID 0x8201
#define AT30TS00_DEVID_MASK 0xffff
#define AT30TSE004_DEVID 0x2200
#define AT30TSE004_DEVID_MASK 0xffff
/* Giantec */
#define GT30TS00_DEVID 0x2200
#define GT30TS00_DEVID_MASK 0xff00
#define GT34TS02_DEVID 0x3300
#define GT34TS02_DEVID_MASK 0xff00
/* IDT */
#define TSE2004_DEVID 0x2200
#define TSE2004_DEVID_MASK 0xff00
#define TS3000_DEVID 0x2900 /* Also matches TSE2002 */
#define TS3000_DEVID_MASK 0xff00
#define TS3001_DEVID 0x3000
#define TS3001_DEVID_MASK 0xff00
/* Maxim */
#define MAX6604_DEVID 0x3e00
#define MAX6604_DEVID_MASK 0xffff
/* Microchip */
#define MCP9804_DEVID 0x0200
#define MCP9804_DEVID_MASK 0xfffc
#define MCP9808_DEVID 0x0400
#define MCP9808_DEVID_MASK 0xfffc
#define MCP98242_DEVID 0x2000
#define MCP98242_DEVID_MASK 0xfffc
#define MCP98243_DEVID 0x2100
#define MCP98243_DEVID_MASK 0xfffc
#define MCP98244_DEVID 0x2200
#define MCP98244_DEVID_MASK 0xfffc
#define MCP9843_DEVID 0x0000 /* Also matches mcp9805 */
#define MCP9843_DEVID_MASK 0xfffe
/* NXP */
#define SE97_DEVID 0xa200
#define SE97_DEVID_MASK 0xfffc
#define SE98_DEVID 0xa100
#define SE98_DEVID_MASK 0xfffc
/* ON Semiconductor */
#define CAT6095_DEVID 0x0800 /* Also matches CAT34TS02 */
#define CAT6095_DEVID_MASK 0xffe0
#define CAT34TS02C_DEVID 0x0a00
#define CAT34TS02C_DEVID_MASK 0xfff0
#define CAT34TS04_DEVID 0x2200
#define CAT34TS04_DEVID_MASK 0xfff0
/* ST Microelectronics */
#define STTS424_DEVID 0x0101
#define STTS424_DEVID_MASK 0xffff
#define STTS424E_DEVID 0x0000
#define STTS424E_DEVID_MASK 0xfffe
#define STTS2002_DEVID 0x0300
#define STTS2002_DEVID_MASK 0xffff
#define STTS2004_DEVID 0x2201
#define STTS2004_DEVID_MASK 0xffff
#define STTS3000_DEVID 0x0200
#define STTS3000_DEVID_MASK 0xffff
static u16 jc42_hysteresis[] = { 0, 1500, 3000, 6000 };
struct jc42_chips {
u16 manid;
u16 devid;
u16 devid_mask;
};
static struct jc42_chips jc42_chips[] = {
{ ADT_MANID, ADT7408_DEVID, ADT7408_DEVID_MASK },
{ ATMEL_MANID, AT30TS00_DEVID, AT30TS00_DEVID_MASK },
{ ATMEL_MANID2, AT30TSE004_DEVID, AT30TSE004_DEVID_MASK },
{ GT_MANID, GT30TS00_DEVID, GT30TS00_DEVID_MASK },
{ GT_MANID2, GT34TS02_DEVID, GT34TS02_DEVID_MASK },
{ IDT_MANID, TSE2004_DEVID, TSE2004_DEVID_MASK },
{ IDT_MANID, TS3000_DEVID, TS3000_DEVID_MASK },
{ IDT_MANID, TS3001_DEVID, TS3001_DEVID_MASK },
{ MAX_MANID, MAX6604_DEVID, MAX6604_DEVID_MASK },
{ MCP_MANID, MCP9804_DEVID, MCP9804_DEVID_MASK },
{ MCP_MANID, MCP9808_DEVID, MCP9808_DEVID_MASK },
{ MCP_MANID, MCP98242_DEVID, MCP98242_DEVID_MASK },
{ MCP_MANID, MCP98243_DEVID, MCP98243_DEVID_MASK },
{ MCP_MANID, MCP98244_DEVID, MCP98244_DEVID_MASK },
{ MCP_MANID, MCP9843_DEVID, MCP9843_DEVID_MASK },
{ NXP_MANID, SE97_DEVID, SE97_DEVID_MASK },
{ ONS_MANID, CAT6095_DEVID, CAT6095_DEVID_MASK },
{ ONS_MANID, CAT34TS02C_DEVID, CAT34TS02C_DEVID_MASK },
{ ONS_MANID, CAT34TS04_DEVID, CAT34TS04_DEVID_MASK },
{ NXP_MANID, SE98_DEVID, SE98_DEVID_MASK },
{ STM_MANID, STTS424_DEVID, STTS424_DEVID_MASK },
{ STM_MANID, STTS424E_DEVID, STTS424E_DEVID_MASK },
{ STM_MANID, STTS2002_DEVID, STTS2002_DEVID_MASK },
{ STM_MANID, STTS2004_DEVID, STTS2004_DEVID_MASK },
{ STM_MANID, STTS3000_DEVID, STTS3000_DEVID_MASK },
};
enum temp_index {
t_input = 0,
t_crit,
t_min,
t_max,
t_num_temp
};
static const u8 temp_regs[t_num_temp] = {
[t_input] = JC42_REG_TEMP,
[t_crit] = JC42_REG_TEMP_CRITICAL,
[t_min] = JC42_REG_TEMP_LOWER,
[t_max] = JC42_REG_TEMP_UPPER,
};
/* Each client has this additional data */
struct jc42_data {
struct i2c_client *client;
struct mutex update_lock; /* protect register access */
bool extended; /* true if extended range supported */
bool valid;
unsigned long last_updated; /* In jiffies */
u16 orig_config; /* original configuration */
u16 config; /* current configuration */
u16 temp[t_num_temp];/* Temperatures */
};
#define JC42_TEMP_MIN_EXTENDED (-40000)
#define JC42_TEMP_MIN 0
#define JC42_TEMP_MAX 125000
static u16 jc42_temp_to_reg(long temp, bool extended)
{
int ntemp = clamp_val(temp,
extended ? JC42_TEMP_MIN_EXTENDED :
JC42_TEMP_MIN, JC42_TEMP_MAX);
/* convert from 0.001 to 0.0625 resolution */
return (ntemp * 2 / 125) & 0x1fff;
}
static int jc42_temp_from_reg(s16 reg)
{
reg = sign_extend32(reg, 12);
/* convert from 0.0625 to 0.001 resolution */
return reg * 125 / 2;
}
static struct jc42_data *jc42_update_device(struct device *dev)
{
struct jc42_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
struct jc42_data *ret = data;
int i, val;
mutex_lock(&data->update_lock);
if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
for (i = 0; i < t_num_temp; i++) {
val = i2c_smbus_read_word_swapped(client, temp_regs[i]);
if (val < 0) {
ret = ERR_PTR(val);
goto abort;
}
data->temp[i] = val;
}
data->last_updated = jiffies;
data->valid = true;
}
abort:
mutex_unlock(&data->update_lock);
return ret;
}
static int jc42_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
struct jc42_data *data = jc42_update_device(dev);
int temp, hyst;
if (IS_ERR(data))
return PTR_ERR(data);
switch (attr) {
case hwmon_temp_input:
*val = jc42_temp_from_reg(data->temp[t_input]);
return 0;
case hwmon_temp_min:
*val = jc42_temp_from_reg(data->temp[t_min]);
return 0;
case hwmon_temp_max:
*val = jc42_temp_from_reg(data->temp[t_max]);
return 0;
case hwmon_temp_crit:
*val = jc42_temp_from_reg(data->temp[t_crit]);
return 0;
case hwmon_temp_max_hyst:
temp = jc42_temp_from_reg(data->temp[t_max]);
hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
>> JC42_CFG_HYST_SHIFT];
*val = temp - hyst;
return 0;
case hwmon_temp_crit_hyst:
temp = jc42_temp_from_reg(data->temp[t_crit]);
hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK)
>> JC42_CFG_HYST_SHIFT];
*val = temp - hyst;
return 0;
case hwmon_temp_min_alarm:
*val = (data->temp[t_input] >> JC42_ALARM_MIN_BIT) & 1;
return 0;
case hwmon_temp_max_alarm:
*val = (data->temp[t_input] >> JC42_ALARM_MAX_BIT) & 1;
return 0;
case hwmon_temp_crit_alarm:
*val = (data->temp[t_input] >> JC42_ALARM_CRIT_BIT) & 1;
return 0;
default:
return -EOPNOTSUPP;
}
}
static int jc42_write(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long val)
{
struct jc42_data *data = dev_get_drvdata(dev);
struct i2c_client *client = data->client;
int diff, hyst;
int ret;
mutex_lock(&data->update_lock);
switch (attr) {
case hwmon_temp_min:
data->temp[t_min] = jc42_temp_to_reg(val, data->extended);
ret = i2c_smbus_write_word_swapped(client, temp_regs[t_min],
data->temp[t_min]);
break;
case hwmon_temp_max:
data->temp[t_max] = jc42_temp_to_reg(val, data->extended);
ret = i2c_smbus_write_word_swapped(client, temp_regs[t_max],
data->temp[t_max]);
break;
case hwmon_temp_crit:
data->temp[t_crit] = jc42_temp_to_reg(val, data->extended);
ret = i2c_smbus_write_word_swapped(client, temp_regs[t_crit],
data->temp[t_crit]);
break;
case hwmon_temp_crit_hyst:
/*
* JC42.4 compliant chips only support four hysteresis values.
* Pick best choice and go from there.
*/
val = clamp_val(val, (data->extended ? JC42_TEMP_MIN_EXTENDED
: JC42_TEMP_MIN) - 6000,
JC42_TEMP_MAX);
diff = jc42_temp_from_reg(data->temp[t_crit]) - val;
hyst = 0;
if (diff > 0) {
if (diff < 2250)
hyst = 1; /* 1.5 degrees C */
else if (diff < 4500)
hyst = 2; /* 3.0 degrees C */
else
hyst = 3; /* 6.0 degrees C */
}
data->config = (data->config & ~JC42_CFG_HYST_MASK) |
(hyst << JC42_CFG_HYST_SHIFT);
ret = i2c_smbus_write_word_swapped(data->client,
JC42_REG_CONFIG,
data->config);
break;
default:
ret = -EOPNOTSUPP;
break;
}
mutex_unlock(&data->update_lock);
return ret;
}
static umode_t jc42_is_visible(const void *_data, enum hwmon_sensor_types type,
u32 attr, int channel)
{
const struct jc42_data *data = _data;
unsigned int config = data->config;
umode_t mode = S_IRUGO;
switch (attr) {
case hwmon_temp_min:
case hwmon_temp_max:
if (!(config & JC42_CFG_EVENT_LOCK))
mode |= S_IWUSR;
break;
case hwmon_temp_crit:
if (!(config & JC42_CFG_TCRIT_LOCK))
mode |= S_IWUSR;
break;
case hwmon_temp_crit_hyst:
if (!(config & (JC42_CFG_EVENT_LOCK | JC42_CFG_TCRIT_LOCK)))
mode |= S_IWUSR;
break;
case hwmon_temp_input:
case hwmon_temp_max_hyst:
case hwmon_temp_min_alarm:
case hwmon_temp_max_alarm:
case hwmon_temp_crit_alarm:
break;
default:
mode = 0;
break;
}
return mode;
}
/* Return 0 if detection is successful, -ENODEV otherwise */
static int jc42_detect(struct i2c_client *client, struct i2c_board_info *info)
{
struct i2c_adapter *adapter = client->adapter;
int i, config, cap, manid, devid;
if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA |
I2C_FUNC_SMBUS_WORD_DATA))
return -ENODEV;
cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
manid = i2c_smbus_read_word_swapped(client, JC42_REG_MANID);
devid = i2c_smbus_read_word_swapped(client, JC42_REG_DEVICEID);
if (cap < 0 || config < 0 || manid < 0 || devid < 0)
return -ENODEV;
if ((cap & 0xff00) || (config & 0xf800))
return -ENODEV;
for (i = 0; i < ARRAY_SIZE(jc42_chips); i++) {
struct jc42_chips *chip = &jc42_chips[i];
if (manid == chip->manid &&
(devid & chip->devid_mask) == chip->devid) {
strlcpy(info->type, "jc42", I2C_NAME_SIZE);
return 0;
}
}
return -ENODEV;
}
static const u32 jc42_temp_config[] = {
HWMON_T_INPUT | HWMON_T_MIN | HWMON_T_MAX | HWMON_T_CRIT |
HWMON_T_MAX_HYST | HWMON_T_CRIT_HYST |
HWMON_T_MIN_ALARM | HWMON_T_MAX_ALARM | HWMON_T_CRIT_ALARM,
0
};
static const struct hwmon_channel_info jc42_temp = {
.type = hwmon_temp,
.config = jc42_temp_config,
};
static const struct hwmon_channel_info *jc42_info[] = {
&jc42_temp,
NULL
};
static const struct hwmon_ops jc42_hwmon_ops = {
.is_visible = jc42_is_visible,
.read = jc42_read,
.write = jc42_write,
};
static const struct hwmon_chip_info jc42_chip_info = {
.ops = &jc42_hwmon_ops,
.info = jc42_info,
};
static int jc42_probe(struct i2c_client *client, const struct i2c_device_id *id)
{
struct device *dev = &client->dev;
struct device *hwmon_dev;
struct jc42_data *data;
int config, cap;
data = devm_kzalloc(dev, sizeof(struct jc42_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
data->client = client;
i2c_set_clientdata(client, data);
mutex_init(&data->update_lock);
cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP);
if (cap < 0)
return cap;
data->extended = !!(cap & JC42_CAP_RANGE);
if (device_property_read_bool(dev, "smbus-timeout-disable")) {
int smbus;
/*
* Not all chips support this register, but from a
* quick read of various datasheets no chip appears
* incompatible with the below attempt to disable
* the timeout. And the whole thing is opt-in...
*/
smbus = i2c_smbus_read_word_swapped(client, JC42_REG_SMBUS);
if (smbus < 0)
return smbus;
i2c_smbus_write_word_swapped(client, JC42_REG_SMBUS,
smbus | SMBUS_STMOUT);
}
config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG);
if (config < 0)
return config;
data->orig_config = config;
if (config & JC42_CFG_SHUTDOWN) {
config &= ~JC42_CFG_SHUTDOWN;
i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
}
data->config = config;
hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
data, &jc42_chip_info,
NULL);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static int jc42_remove(struct i2c_client *client)
{
struct jc42_data *data = i2c_get_clientdata(client);
/* Restore original configuration except hysteresis */
if ((data->config & ~JC42_CFG_HYST_MASK) !=
(data->orig_config & ~JC42_CFG_HYST_MASK)) {
int config;
config = (data->orig_config & ~JC42_CFG_HYST_MASK)
| (data->config & JC42_CFG_HYST_MASK);
i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config);
}
return 0;
}
#ifdef CONFIG_PM
static int jc42_suspend(struct device *dev)
{
struct jc42_data *data = dev_get_drvdata(dev);
data->config |= JC42_CFG_SHUTDOWN;
i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
data->config);
return 0;
}
static int jc42_resume(struct device *dev)
{
struct jc42_data *data = dev_get_drvdata(dev);
data->config &= ~JC42_CFG_SHUTDOWN;
i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG,
data->config);
return 0;
}
static const struct dev_pm_ops jc42_dev_pm_ops = {
.suspend = jc42_suspend,
.resume = jc42_resume,
};
#define JC42_DEV_PM_OPS (&jc42_dev_pm_ops)
#else
#define JC42_DEV_PM_OPS NULL
#endif /* CONFIG_PM */
static const struct i2c_device_id jc42_id[] = {
{ "jc42", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, jc42_id);
#ifdef CONFIG_OF
static const struct of_device_id jc42_of_ids[] = {
{ .compatible = "jedec,jc-42.4-temp", },
{ }
};
MODULE_DEVICE_TABLE(of, jc42_of_ids);
#endif
static struct i2c_driver jc42_driver = {
.class = I2C_CLASS_SPD | I2C_CLASS_HWMON,
.driver = {
.name = "jc42",
.pm = JC42_DEV_PM_OPS,
.of_match_table = of_match_ptr(jc42_of_ids),
},
.probe = jc42_probe,
.remove = jc42_remove,
.id_table = jc42_id,
.detect = jc42_detect,
.address_list = normal_i2c,
};
module_i2c_driver(jc42_driver);
MODULE_AUTHOR("Guenter Roeck <linux@roeck-us.net>");
MODULE_DESCRIPTION("JC42 driver");
MODULE_LICENSE("GPL");
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