static int w1_strong_pullup = 1;
module_param_named(strong_pullup, w1_strong_pullup, int, 0);
+/* This command should be in public header w1.h but is not */
+#define W1_RECALL_EEPROM 0xB8
+
/* Nb of try for an operation */
#define W1_THERM_MAX_TRY 5
/* ms delay to retry bus mutex */
#define W1_THERM_RETRY_DELAY 20
+/* delay in ms to write in EEPROM */
+#define W1_THERM_EEPROM_WRITE_DELAY 10
+
+#define EEPROM_CMD_WRITE "save" /* cmd for write eeprom sysfs */
+#define EEPROM_CMD_READ "restore" /* cmd for read eeprom sysfs */
+
/* Helpers Macros */
/*
* @convert: pointer to the device conversion function
* @set_resolution: pointer to the device set_resolution function
* @get_resolution: pointer to the device get_resolution function
- * @eeprom: pointer to eeprom function
*/
struct w1_therm_family_converter {
u8 broken;
int (*convert)(u8 rom[9]);
int (*set_resolution)(struct w1_slave *sl, int val);
int (*get_resolution)(struct w1_slave *sl);
- int (*eeprom)(struct device *device);
};
/**
*/
static int write_scratchpad(struct w1_slave *sl, const u8 *data, u8 nb_bytes);
+/**
+ * copy_scratchpad() - Copy the content of scratchpad in device EEPROM
+ * @sl: slave involved
+ *
+ * Return: 0 if success, -kernel error code otherwise
+ */
+static int copy_scratchpad(struct w1_slave *sl);
+
+/**
+ * recall_eeprom() - Restore EEPROM data to device RAM
+ * @sl: slave involved
+ *
+ * Return: 0 if success, -kernel error code otherwise
+ */
+static int recall_eeprom(struct w1_slave *sl);
+
/**
* read_powermode() - Query the power mode of the slave
* @sl: slave to retrieve the power mode
static ssize_t resolution_store(struct device *device,
struct device_attribute *attr, const char *buf, size_t size);
+static ssize_t eeprom_store(struct device *device,
+ struct device_attribute *attr, const char *buf, size_t size);
+
/* Attributes declarations */
static DEVICE_ATTR_RW(w1_slave);
static DEVICE_ATTR_RO(w1_seq);
static DEVICE_ATTR_RO(ext_power);
static DEVICE_ATTR_RW(resolution);
+static DEVICE_ATTR_WO(eeprom);
/* Interface Functions declaration */
&dev_attr_w1_slave.attr,
&dev_attr_ext_power.attr,
&dev_attr_resolution.attr,
+ &dev_attr_eeprom.attr,
NULL,
};
static struct attribute *w1_ds18s20_attrs[] = {
&dev_attr_w1_slave.attr,
&dev_attr_ext_power.attr,
+ &dev_attr_eeprom.attr,
NULL,
};
&dev_attr_w1_seq.attr,
&dev_attr_ext_power.attr,
&dev_attr_resolution.attr,
+ &dev_attr_eeprom.attr,
NULL,
};
/* Device dependent func */
-/* write configuration to eeprom */
-static inline int w1_therm_eeprom(struct device *device);
-
static inline int w1_DS18B20_write_data(struct w1_slave *sl,
const u8 *data)
{
.convert = w1_DS18S20_convert_temp,
.set_resolution = NULL, /* no config register */
.get_resolution = NULL, /* no config register */
- .eeprom = w1_therm_eeprom
},
{
.f = &w1_therm_family_DS1822,
.convert = w1_DS18B20_convert_temp,
.set_resolution = w1_DS18B20_set_resolution,
.get_resolution = w1_DS18B20_get_resolution,
- .eeprom = w1_therm_eeprom
},
{
.f = &w1_therm_family_DS18B20,
.convert = w1_DS18B20_convert_temp,
.set_resolution = w1_DS18B20_set_resolution,
.get_resolution = w1_DS18B20_get_resolution,
- .eeprom = w1_therm_eeprom
},
{
.f = &w1_therm_family_DS28EA00,
.convert = w1_DS18B20_convert_temp,
.set_resolution = w1_DS18B20_set_resolution,
.get_resolution = w1_DS18B20_get_resolution,
- .eeprom = w1_therm_eeprom
},
{
.f = &w1_therm_family_DS1825,
.convert = w1_DS18B20_convert_temp,
.set_resolution = w1_DS18B20_set_resolution,
.get_resolution = w1_DS18B20_get_resolution,
- .eeprom = w1_therm_eeprom
}
};
return ret;
}
-static inline int w1_therm_eeprom(struct device *device)
+static int copy_scratchpad(struct w1_slave *sl)
{
- struct w1_slave *sl = dev_to_w1_slave(device);
- struct w1_master *dev = sl->master;
- u8 rom[9], external_power;
- int ret, max_trying = 10;
- u8 *family_data = sl->family_data;
+ struct w1_master *dev_master = sl->master;
+ int max_trying = W1_THERM_MAX_TRY;
+ int t_write, ret = -ENODEV;
+ bool strong_pullup;
- if (!sl->family_data) {
- ret = -ENODEV;
+ if (!sl->family_data)
goto error;
- }
+
+ t_write = W1_THERM_EEPROM_WRITE_DELAY;
+ strong_pullup = (w1_strong_pullup == 2 ||
+ (!SLAVE_POWERMODE(sl) &&
+ w1_strong_pullup));
/* prevent the slave from going away in sleep */
- atomic_inc(THERM_REFCNT(family_data));
+ atomic_inc(THERM_REFCNT(sl->family_data));
- ret = mutex_lock_interruptible(&dev->bus_mutex);
- if (ret != 0)
+ if (!bus_mutex_lock(&dev_master->bus_mutex)) {
+ ret = -EAGAIN; /* Didn't acquire the mutex */
goto dec_refcnt;
+ }
- memset(rom, 0, sizeof(rom));
-
- while (max_trying--) {
+ while (max_trying-- && ret) { /* ret should be 0 */
+ /* safe version to select slave */
if (!reset_select_slave(sl)) {
- unsigned int tm = 10;
unsigned long sleep_rem;
- /* check if in parasite mode */
- w1_write_8(dev, W1_READ_PSUPPLY);
- external_power = w1_read_8(dev);
-
- if (reset_select_slave(sl))
- continue;
-
- /* 10ms strong pullup/delay after the copy command */
- if (w1_strong_pullup == 2 ||
- (!external_power && w1_strong_pullup))
- w1_next_pullup(dev, tm);
+ /* 10ms strong pullup (or delay) after the convert */
+ if (strong_pullup)
+ w1_next_pullup(dev_master, t_write);
- w1_write_8(dev, W1_COPY_SCRATCHPAD);
-
- if (external_power) {
- mutex_unlock(&dev->bus_mutex);
+ w1_write_8(dev_master, W1_COPY_SCRATCHPAD);
- sleep_rem = msleep_interruptible(tm);
- if (sleep_rem != 0) {
- ret = -EINTR;
- goto dec_refcnt;
- }
-
- ret = mutex_lock_interruptible(&dev->bus_mutex);
- if (ret != 0)
- goto dec_refcnt;
- } else if (!w1_strong_pullup) {
- sleep_rem = msleep_interruptible(tm);
+ if (strong_pullup) {
+ sleep_rem = msleep_interruptible(t_write);
if (sleep_rem != 0) {
ret = -EINTR;
goto mt_unlock;
}
}
-
- break;
+ ret = 0;
}
+
}
mt_unlock:
- mutex_unlock(&dev->bus_mutex);
+ mutex_unlock(&dev_master->bus_mutex);
dec_refcnt:
- atomic_dec(THERM_REFCNT(family_data));
+ atomic_dec(THERM_REFCNT(sl->family_data));
+error:
+ return ret;
+}
+
+static int recall_eeprom(struct w1_slave *sl)
+{
+ struct w1_master *dev_master = sl->master;
+ int max_trying = W1_THERM_MAX_TRY;
+ int ret = -ENODEV;
+
+ if (!sl->family_data)
+ goto error;
+
+ /* prevent the slave from going away in sleep */
+ atomic_inc(THERM_REFCNT(sl->family_data));
+
+ if (!bus_mutex_lock(&dev_master->bus_mutex)) {
+ ret = -EAGAIN; /* Didn't acquire the mutex */
+ goto dec_refcnt;
+ }
+
+ while (max_trying-- && ret) { /* ret should be 0 */
+ /* safe version to select slave */
+ if (!reset_select_slave(sl)) {
+
+ w1_write_8(dev_master, W1_RECALL_EEPROM);
+
+ ret = 1; /* Slave will pull line to 0 */
+ while (ret)
+ ret = 1 - w1_touch_bit(dev_master, 1);
+ }
+
+ }
+
+ mutex_unlock(&dev_master->bus_mutex);
+
+dec_refcnt:
+ atomic_dec(THERM_REFCNT(sl->family_data));
error:
return ret;
}
}
if (val == 0) /* val=0 : trigger a EEPROM save */
- ret = SLAVE_SPECIFIC_FUNC(sl)->eeprom(device);
+ ret = copy_scratchpad(sl);
else {
if (SLAVE_SPECIFIC_FUNC(sl)->set_resolution)
ret = SLAVE_SPECIFIC_FUNC(sl)->set_resolution(sl, val);
return size;
}
+static ssize_t eeprom_store(struct device *device,
+ struct device_attribute *attr, const char *buf, size_t size)
+{
+ struct w1_slave *sl = dev_to_w1_slave(device);
+ int ret = -EINVAL; /* Invalid argument */
+
+ if (size == sizeof(EEPROM_CMD_WRITE)) {
+ if (!strncmp(buf, EEPROM_CMD_WRITE, sizeof(EEPROM_CMD_WRITE)-1))
+ ret = copy_scratchpad(sl);
+ } else if (size == sizeof(EEPROM_CMD_READ)) {
+ if (!strncmp(buf, EEPROM_CMD_READ, sizeof(EEPROM_CMD_READ)-1))
+ ret = recall_eeprom(sl);
+ }
+
+ if (ret)
+ dev_info(device, "%s: error in process %d\n", __func__, ret);
+
+ return size;
+}
+
#if IS_REACHABLE(CONFIG_HWMON)
static int w1_read_temp(struct device *device, u32 attr, int channel,
long *val)
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