62b7f5931c
bcm2708: boot tested on RPi B+ v1.2
bcm2709: boot tested on RPi 3B v1.2 and RPi 4B v1.1 4G
bcm2710: boot tested on RPi 3B v1.2
bcm2711: boot tested on RPi 4B v1.1 4G
Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
(cherry-picked from commit f07e572f64)
581 lines
15 KiB
Diff
581 lines
15 KiB
Diff
From 7c49e87acd0412ff1fb2490c4ac6fcb5471afd9b Mon Sep 17 00:00:00 2001
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From: Akira Shimahara <akira215corp@gmail.com>
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Date: Mon, 11 May 2020 22:35:35 +0200
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Subject: [PATCH] w1_therm: adding code comments and code reordering
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commit 92b8d2724464bc1d2e735a84c0da5741dce33485 upstream.
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Adding code comments to split code in dedicated parts. After the global
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declarations (defines, macros and function declarations), code is organized
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as follow :
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- Device and family dependent structures and functions
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- Interfaces functions
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- Helpers functions
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- Hardware functions
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- Sysfs interface functions
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Signed-off-by: Akira Shimahara <akira215corp@gmail.com>
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Link: https://lore.kernel.org/r/20200511203535.409599-1-akira215corp@gmail.com
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Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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---
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drivers/w1/slaves/w1_therm.c | 427 +++++++++++++++++++++--------------
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1 file changed, 259 insertions(+), 168 deletions(-)
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--- a/drivers/w1/slaves/w1_therm.c
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+++ b/drivers/w1/slaves/w1_therm.c
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@@ -25,7 +25,8 @@
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#define W1_THERM_DS1825 0x3B
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#define W1_THERM_DS28EA00 0x42
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-/* Allow the strong pullup to be disabled, but default to enabled.
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+/*
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+ * Allow the strong pullup to be disabled, but default to enabled.
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* If it was disabled a parasite powered device might not get the require
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* current to do a temperature conversion. If it is enabled parasite powered
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* devices have a better chance of getting the current required.
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@@ -41,42 +42,55 @@
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static int w1_strong_pullup = 1;
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module_param_named(strong_pullup, w1_strong_pullup, int, 0);
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+/* Helpers Macros */
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+
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+/* return the address of the refcnt in the family data */
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+#define THERM_REFCNT(family_data) \
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+ (&((struct w1_therm_family_data *)family_data)->refcnt)
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+
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+/* Structs definition */
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+
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+/**
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+ * struct w1_therm_family_converter - bind device specific functions
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+ * @broken: flag for non-registred families
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+ * @reserved: not used here
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+ * @f: pointer to the device binding structure
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+ * @convert: pointer to the device conversion function
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+ * @precision: pointer to the device precision function
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+ * @eeprom: pointer to eeprom function
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+ */
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+struct w1_therm_family_converter {
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+ u8 broken;
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+ u16 reserved;
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+ struct w1_family *f;
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+ int (*convert)(u8 rom[9]);
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+ int (*precision)(struct device *device, int val);
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+ int (*eeprom)(struct device *device);
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+};
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+
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+/**
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+ * struct w1_therm_family_data - device data
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+ * @rom: ROM device id (64bit Lasered ROM code + 1 CRC byte)
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+ * @refcnt: ref count
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+ */
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struct w1_therm_family_data {
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uint8_t rom[9];
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atomic_t refcnt;
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};
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+/**
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+ * struct therm_info - store temperature reading
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+ * @rom: read device data (8 data bytes + 1 CRC byte)
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+ * @crc: computed crc from rom
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+ * @verdict: 1 crc checked, 0 crc not matching
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+ */
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struct therm_info {
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u8 rom[9];
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u8 crc;
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u8 verdict;
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};
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-/* return the address of the refcnt in the family data */
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-#define THERM_REFCNT(family_data) \
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- (&((struct w1_therm_family_data *)family_data)->refcnt)
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-
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-static int w1_therm_add_slave(struct w1_slave *sl)
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-{
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- sl->family_data = kzalloc(sizeof(struct w1_therm_family_data),
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- GFP_KERNEL);
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- if (!sl->family_data)
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- return -ENOMEM;
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- atomic_set(THERM_REFCNT(sl->family_data), 1);
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- return 0;
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-}
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-
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-static void w1_therm_remove_slave(struct w1_slave *sl)
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-{
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- int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data));
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-
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- while (refcnt) {
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- msleep(1000);
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- refcnt = atomic_read(THERM_REFCNT(sl->family_data));
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- }
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- kfree(sl->family_data);
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- sl->family_data = NULL;
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-}
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+/* Sysfs interface declaration */
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static ssize_t w1_slave_show(struct device *device,
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struct device_attribute *attr, char *buf);
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@@ -87,9 +101,35 @@ static ssize_t w1_slave_store(struct dev
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static ssize_t w1_seq_show(struct device *device,
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struct device_attribute *attr, char *buf);
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+/* Attributes declarations */
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+
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static DEVICE_ATTR_RW(w1_slave);
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static DEVICE_ATTR_RO(w1_seq);
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+/* Interface Functions declaration */
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+
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+/**
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+ * w1_therm_add_slave() - Called when a new slave is discovered
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+ * @sl: slave just discovered by the master.
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+ *
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+ * Called by the master when the slave is discovered on the bus. Used to
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+ * initialize slave state before the beginning of any communication.
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+ *
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+ * Return: 0 - If success, negative kernel code otherwise
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+ */
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+static int w1_therm_add_slave(struct w1_slave *sl);
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+
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+/**
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+ * w1_therm_remove_slave() - Called when a slave is removed
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+ * @sl: slave to be removed.
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+ *
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+ * Called by the master when the slave is considered not to be on the bus
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+ * anymore. Used to free memory.
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+ */
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+static void w1_therm_remove_slave(struct w1_slave *sl);
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+
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+/* Family attributes */
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+
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static struct attribute *w1_therm_attrs[] = {
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&dev_attr_w1_slave.attr,
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NULL,
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@@ -101,6 +141,8 @@ static struct attribute *w1_ds28ea00_att
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NULL,
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};
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+/* Attribute groups */
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+
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ATTRIBUTE_GROUPS(w1_therm);
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ATTRIBUTE_GROUPS(w1_ds28ea00);
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@@ -154,6 +196,8 @@ static const struct hwmon_chip_info w1_c
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#define W1_CHIPINFO NULL
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#endif
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+/* Family operations */
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+
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static struct w1_family_ops w1_therm_fops = {
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.add_slave = w1_therm_add_slave,
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.remove_slave = w1_therm_remove_slave,
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@@ -168,6 +212,8 @@ static struct w1_family_ops w1_ds28ea00_
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.chip_info = W1_CHIPINFO,
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};
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+/* Family binding operations struct */
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+
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static struct w1_family w1_therm_family_DS18S20 = {
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.fid = W1_THERM_DS18S20,
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.fops = &w1_therm_fops,
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@@ -193,138 +239,18 @@ static struct w1_family w1_therm_family_
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.fops = &w1_therm_fops,
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};
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-struct w1_therm_family_converter {
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- u8 broken;
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- u16 reserved;
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- struct w1_family *f;
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- int (*convert)(u8 rom[9]);
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- int (*precision)(struct device *device, int val);
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- int (*eeprom)(struct device *device);
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-};
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+/* Device dependent func */
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/* write configuration to eeprom */
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static inline int w1_therm_eeprom(struct device *device);
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-/* Set precision for conversion */
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-static inline int w1_DS18B20_precision(struct device *device, int val);
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-static inline int w1_DS18S20_precision(struct device *device, int val);
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-
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-/* The return value is millidegrees Centigrade. */
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-static inline int w1_DS18B20_convert_temp(u8 rom[9]);
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-static inline int w1_DS18S20_convert_temp(u8 rom[9]);
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-
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-static struct w1_therm_family_converter w1_therm_families[] = {
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- {
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- .f = &w1_therm_family_DS18S20,
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- .convert = w1_DS18S20_convert_temp,
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- .precision = w1_DS18S20_precision,
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- .eeprom = w1_therm_eeprom
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- },
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- {
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- .f = &w1_therm_family_DS1822,
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- .convert = w1_DS18B20_convert_temp,
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- .precision = w1_DS18S20_precision,
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- .eeprom = w1_therm_eeprom
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- },
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- {
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- .f = &w1_therm_family_DS18B20,
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- .convert = w1_DS18B20_convert_temp,
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- .precision = w1_DS18B20_precision,
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- .eeprom = w1_therm_eeprom
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- },
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- {
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- .f = &w1_therm_family_DS28EA00,
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- .convert = w1_DS18B20_convert_temp,
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- .precision = w1_DS18S20_precision,
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- .eeprom = w1_therm_eeprom
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- },
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- {
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- .f = &w1_therm_family_DS1825,
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- .convert = w1_DS18B20_convert_temp,
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- .precision = w1_DS18S20_precision,
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- .eeprom = w1_therm_eeprom
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- }
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-};
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-
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-static inline int w1_therm_eeprom(struct device *device)
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-{
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- struct w1_slave *sl = dev_to_w1_slave(device);
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- struct w1_master *dev = sl->master;
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- u8 rom[9], external_power;
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- int ret, max_trying = 10;
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- u8 *family_data = sl->family_data;
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-
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- if (!sl->family_data) {
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- ret = -ENODEV;
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- goto error;
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- }
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-
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- /* prevent the slave from going away in sleep */
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- atomic_inc(THERM_REFCNT(family_data));
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-
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- ret = mutex_lock_interruptible(&dev->bus_mutex);
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- if (ret != 0)
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- goto dec_refcnt;
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-
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- memset(rom, 0, sizeof(rom));
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-
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- while (max_trying--) {
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- if (!w1_reset_select_slave(sl)) {
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- unsigned int tm = 10;
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- unsigned long sleep_rem;
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-
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- /* check if in parasite mode */
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- w1_write_8(dev, W1_READ_PSUPPLY);
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- external_power = w1_read_8(dev);
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-
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- if (w1_reset_select_slave(sl))
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- continue;
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-
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- /* 10ms strong pullup/delay after the copy command */
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- if (w1_strong_pullup == 2 ||
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- (!external_power && w1_strong_pullup))
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- w1_next_pullup(dev, tm);
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-
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- w1_write_8(dev, W1_COPY_SCRATCHPAD);
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-
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- if (external_power) {
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- mutex_unlock(&dev->bus_mutex);
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-
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- sleep_rem = msleep_interruptible(tm);
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- if (sleep_rem != 0) {
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- ret = -EINTR;
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- goto dec_refcnt;
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- }
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-
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- ret = mutex_lock_interruptible(&dev->bus_mutex);
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- if (ret != 0)
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- goto dec_refcnt;
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- } else if (!w1_strong_pullup) {
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- sleep_rem = msleep_interruptible(tm);
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- if (sleep_rem != 0) {
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- ret = -EINTR;
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- goto mt_unlock;
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- }
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- }
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-
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- break;
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- }
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- }
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-
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-mt_unlock:
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- mutex_unlock(&dev->bus_mutex);
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-dec_refcnt:
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- atomic_dec(THERM_REFCNT(family_data));
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-error:
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- return ret;
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-}
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-
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/* DS18S20 does not feature configuration register */
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static inline int w1_DS18S20_precision(struct device *device, int val)
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{
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return 0;
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}
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+/* Set precision for conversion */
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static inline int w1_DS18B20_precision(struct device *device, int val)
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{
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struct w1_slave *sl = dev_to_w1_slave(device);
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@@ -407,6 +333,14 @@ error:
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return ret;
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}
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+/**
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+ * w1_DS18B20_convert_temp() - temperature computation for DS18B20
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+ * @rom: data read from device RAM (8 data bytes + 1 CRC byte)
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+ *
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+ * Can be called for any DS18B20 compliant device.
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+ *
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+ * Return: value in millidegrees Celsius.
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+ */
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static inline int w1_DS18B20_convert_temp(u8 rom[9])
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{
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s16 t = le16_to_cpup((__le16 *)rom);
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@@ -414,6 +348,14 @@ static inline int w1_DS18B20_convert_tem
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return t*1000/16;
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}
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+/**
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+ * w1_DS18S20_convert_temp() - temperature computation for DS18S20
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+ * @rom: data read from device RAM (8 data bytes + 1 CRC byte)
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+ *
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+ * Can be called for any DS18S20 compliant device.
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+ *
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+ * Return: value in millidegrees Celsius.
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+ */
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static inline int w1_DS18S20_convert_temp(u8 rom[9])
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{
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int t, h;
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@@ -434,6 +376,53 @@ static inline int w1_DS18S20_convert_tem
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return t;
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}
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+/* Device capability description */
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+
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+static struct w1_therm_family_converter w1_therm_families[] = {
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+ {
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+ .f = &w1_therm_family_DS18S20,
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+ .convert = w1_DS18S20_convert_temp,
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+ .precision = w1_DS18S20_precision,
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+ .eeprom = w1_therm_eeprom
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+ },
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+ {
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+ .f = &w1_therm_family_DS1822,
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+ .convert = w1_DS18B20_convert_temp,
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+ .precision = w1_DS18S20_precision,
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+ .eeprom = w1_therm_eeprom
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+ },
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+ {
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+ .f = &w1_therm_family_DS18B20,
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+ .convert = w1_DS18B20_convert_temp,
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+ .precision = w1_DS18B20_precision,
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+ .eeprom = w1_therm_eeprom
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+ },
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+ {
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+ .f = &w1_therm_family_DS28EA00,
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+ .convert = w1_DS18B20_convert_temp,
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+ .precision = w1_DS18S20_precision,
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+ .eeprom = w1_therm_eeprom
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+ },
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+ {
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+ .f = &w1_therm_family_DS1825,
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+ .convert = w1_DS18B20_convert_temp,
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+ .precision = w1_DS18S20_precision,
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+ .eeprom = w1_therm_eeprom
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+ }
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+};
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+
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+/* Helpers Functions */
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+
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+/**
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+ * w1_convert_temp() - temperature conversion binding function
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+ * @rom: data read from device RAM (8 data bytes + 1 CRC byte)
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+ * @fid: device family id
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+ *
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+ * The function call the temperature computation function according to
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+ * device family.
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+ *
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+ * Return: value in millidegrees Celsius.
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+ */
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static inline int w1_convert_temp(u8 rom[9], u8 fid)
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{
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int i;
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@@ -445,31 +434,32 @@ static inline int w1_convert_temp(u8 rom
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return 0;
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}
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-static ssize_t w1_slave_store(struct device *device,
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- struct device_attribute *attr, const char *buf,
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- size_t size)
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+/* Interface Functions */
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+
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+static int w1_therm_add_slave(struct w1_slave *sl)
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{
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- int val, ret;
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- struct w1_slave *sl = dev_to_w1_slave(device);
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- int i;
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+ sl->family_data = kzalloc(sizeof(struct w1_therm_family_data),
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+ GFP_KERNEL);
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+ if (!sl->family_data)
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+ return -ENOMEM;
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+ atomic_set(THERM_REFCNT(sl->family_data), 1);
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+ return 0;
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+}
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- ret = kstrtoint(buf, 0, &val);
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- if (ret)
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- return ret;
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+static void w1_therm_remove_slave(struct w1_slave *sl)
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+{
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+ int refcnt = atomic_sub_return(1, THERM_REFCNT(sl->family_data));
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- for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
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- if (w1_therm_families[i].f->fid == sl->family->fid) {
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- /* zero value indicates to write current configuration to eeprom */
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- if (val == 0)
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- ret = w1_therm_families[i].eeprom(device);
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- else
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- ret = w1_therm_families[i].precision(device, val);
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- break;
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- }
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+ while (refcnt) {
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+ msleep(1000);
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+ refcnt = atomic_read(THERM_REFCNT(sl->family_data));
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}
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- return ret ? : size;
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+ kfree(sl->family_data);
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+ sl->family_data = NULL;
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}
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+/* Hardware Functions */
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+
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static ssize_t read_therm(struct device *device,
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struct w1_slave *sl, struct therm_info *info)
|
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{
|
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@@ -564,6 +554,81 @@ error:
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return ret;
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}
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|
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+static inline int w1_therm_eeprom(struct device *device)
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+{
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+ struct w1_slave *sl = dev_to_w1_slave(device);
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+ struct w1_master *dev = sl->master;
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+ u8 rom[9], external_power;
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+ int ret, max_trying = 10;
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+ u8 *family_data = sl->family_data;
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|
+
|
|
+ if (!sl->family_data) {
|
|
+ ret = -ENODEV;
|
|
+ goto error;
|
|
+ }
|
|
+
|
|
+ /* prevent the slave from going away in sleep */
|
|
+ atomic_inc(THERM_REFCNT(family_data));
|
|
+
|
|
+ ret = mutex_lock_interruptible(&dev->bus_mutex);
|
|
+ if (ret != 0)
|
|
+ goto dec_refcnt;
|
|
+
|
|
+ memset(rom, 0, sizeof(rom));
|
|
+
|
|
+ while (max_trying--) {
|
|
+ if (!w1_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 (w1_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);
|
|
+
|
|
+ w1_write_8(dev, W1_COPY_SCRATCHPAD);
|
|
+
|
|
+ if (external_power) {
|
|
+ mutex_unlock(&dev->bus_mutex);
|
|
+
|
|
+ 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 (sleep_rem != 0) {
|
|
+ ret = -EINTR;
|
|
+ goto mt_unlock;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ break;
|
|
+ }
|
|
+ }
|
|
+
|
|
+mt_unlock:
|
|
+ mutex_unlock(&dev->bus_mutex);
|
|
+dec_refcnt:
|
|
+ atomic_dec(THERM_REFCNT(family_data));
|
|
+error:
|
|
+ return ret;
|
|
+}
|
|
+
|
|
+/* Sysfs Interface definition */
|
|
+
|
|
static ssize_t w1_slave_show(struct device *device,
|
|
struct device_attribute *attr, char *buf)
|
|
{
|
|
@@ -597,6 +662,32 @@ static ssize_t w1_slave_show(struct devi
|
|
return ret;
|
|
}
|
|
|
|
+static ssize_t w1_slave_store(struct device *device,
|
|
+ struct device_attribute *attr, const char *buf,
|
|
+ size_t size)
|
|
+{
|
|
+ int val, ret;
|
|
+ struct w1_slave *sl = dev_to_w1_slave(device);
|
|
+ int i;
|
|
+
|
|
+ ret = kstrtoint(buf, 0, &val);
|
|
+ if (ret)
|
|
+ return ret;
|
|
+
|
|
+ for (i = 0; i < ARRAY_SIZE(w1_therm_families); ++i) {
|
|
+ if (w1_therm_families[i].f->fid == sl->family->fid) {
|
|
+ /* zero value indicates to write current configuration to eeprom */
|
|
+ if (val == 0)
|
|
+ ret = w1_therm_families[i].eeprom(device);
|
|
+ else
|
|
+ ret = w1_therm_families[i].precision(device,
|
|
+ val);
|
|
+ break;
|
|
+ }
|
|
+ }
|
|
+ return ret ? : size;
|
|
+}
|
|
+
|
|
#if IS_REACHABLE(CONFIG_HWMON)
|
|
static int w1_read_temp(struct device *device, u32 attr, int channel,
|
|
long *val)
|
|
@@ -666,7 +757,7 @@ static ssize_t w1_seq_show(struct device
|
|
if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
|
|
goto error;
|
|
|
|
- /* In case the bus fails to send 0xFF, limit*/
|
|
+ /* In case the bus fails to send 0xFF, limit */
|
|
for (i = 0; i <= 64; i++) {
|
|
if (w1_reset_bus(sl->master))
|
|
goto error;
|