+++ /dev/null
-From a603c307f7348255d19b6031254aac0080e99c37 Mon Sep 17 00:00:00 2001
-From: Phil Elwell <pelwell@users.noreply.github.com>
-Date: Mon, 13 Jul 2015 13:25:31 +0100
-Subject: [PATCH 119/222] Merge pull request #1059 from pelwell/rpi-4.0.y
-
-w1_therm: Back-port locking improvements from 4.2-rc1
----
- Documentation/ABI/stable/sysfs-driver-w1_ds28ea00 | 6 ++
- Documentation/w1/slaves/w1_therm | 11 ++-
- drivers/w1/slaves/w1_therm.c | 102 +++++++++++++++++++++-
- 3 files changed, 117 insertions(+), 2 deletions(-)
- create mode 100644 Documentation/ABI/stable/sysfs-driver-w1_ds28ea00
-
---- /dev/null
-+++ b/Documentation/ABI/stable/sysfs-driver-w1_ds28ea00
-@@ -0,0 +1,6 @@
-+What: /sys/bus/w1/devices/.../w1_seq
-+Date: Apr 2015
-+Contact: Matt Campbell <mattrcampbell@gmail.com>
-+Description: Support for the DS28EA00 chain sequence function
-+ see Documentation/w1/slaves/w1_therm for detailed information
-+Users: any user space application which wants to communicate with DS28EA00
---- a/Documentation/w1/slaves/w1_therm
-+++ b/Documentation/w1/slaves/w1_therm
-@@ -11,12 +11,14 @@ Author: Evgeniy Polyakov <johnpol@2ka.mi
- Description
- -----------
-
--w1_therm provides basic temperature conversion for ds18*20 devices.
-+w1_therm provides basic temperature conversion for ds18*20 devices, and the
-+ds28ea00 device.
- supported family codes:
- W1_THERM_DS18S20 0x10
- W1_THERM_DS1822 0x22
- W1_THERM_DS18B20 0x28
- W1_THERM_DS1825 0x3B
-+W1_THERM_DS28EA00 0x42
-
- Support is provided through the sysfs w1_slave file. Each open and
- read sequence will initiate a temperature conversion then provide two
-@@ -48,3 +50,10 @@ resistor). The DS18b20 temperature sens
- maximum current draw of 1.5mA and that a 5k pullup resistor is not
- sufficient. The strong pullup is designed to provide the additional
- current required.
-+
-+The DS28EA00 provides an additional two pins for implementing a sequence
-+detection algorithm. This feature allows you to determine the physical
-+location of the chip in the 1-wire bus without needing pre-existing
-+knowledge of the bus ordering. Support is provided through the sysfs
-+w1_seq file. The file will contain a single line with an integer value
-+representing the device index in the bus starting at 0.
---- a/drivers/w1/slaves/w1_therm.c
-+++ b/drivers/w1/slaves/w1_therm.c
-@@ -92,13 +92,24 @@ static void w1_therm_remove_slave(struct
- static ssize_t w1_slave_show(struct device *device,
- struct device_attribute *attr, char *buf);
-
-+static ssize_t w1_seq_show(struct device *device,
-+ struct device_attribute *attr, char *buf);
-+
- static DEVICE_ATTR_RO(w1_slave);
-+static DEVICE_ATTR_RO(w1_seq);
-
- static struct attribute *w1_therm_attrs[] = {
- &dev_attr_w1_slave.attr,
- NULL,
- };
-+
-+static struct attribute *w1_ds28ea00_attrs[] = {
-+ &dev_attr_w1_slave.attr,
-+ &dev_attr_w1_seq.attr,
-+ NULL,
-+};
- ATTRIBUTE_GROUPS(w1_therm);
-+ATTRIBUTE_GROUPS(w1_ds28ea00);
-
- static struct w1_family_ops w1_therm_fops = {
- .add_slave = w1_therm_add_slave,
-@@ -106,6 +117,12 @@ static struct w1_family_ops w1_therm_fop
- .groups = w1_therm_groups,
- };
-
-+static struct w1_family_ops w1_ds28ea00_fops = {
-+ .add_slave = w1_therm_add_slave,
-+ .remove_slave = w1_therm_remove_slave,
-+ .groups = w1_ds28ea00_groups,
-+};
-+
- static struct w1_family w1_therm_family_DS18S20 = {
- .fid = W1_THERM_DS18S20,
- .fops = &w1_therm_fops,
-@@ -123,7 +140,7 @@ static struct w1_family w1_therm_family_
-
- static struct w1_family w1_therm_family_DS28EA00 = {
- .fid = W1_THERM_DS28EA00,
-- .fops = &w1_therm_fops,
-+ .fops = &w1_ds28ea00_fops,
- };
-
- static struct w1_family w1_therm_family_DS1825 = {
-@@ -316,6 +333,89 @@ post_unlock:
- return ret;
- }
-
-+#define W1_42_CHAIN 0x99
-+#define W1_42_CHAIN_OFF 0x3C
-+#define W1_42_CHAIN_OFF_INV 0xC3
-+#define W1_42_CHAIN_ON 0x5A
-+#define W1_42_CHAIN_ON_INV 0xA5
-+#define W1_42_CHAIN_DONE 0x96
-+#define W1_42_CHAIN_DONE_INV 0x69
-+#define W1_42_COND_READ 0x0F
-+#define W1_42_SUCCESS_CONFIRM_BYTE 0xAA
-+#define W1_42_FINISHED_BYTE 0xFF
-+static ssize_t w1_seq_show(struct device *device,
-+ struct device_attribute *attr, char *buf)
-+{
-+ struct w1_slave *sl = dev_to_w1_slave(device);
-+ ssize_t c = PAGE_SIZE;
-+ int rv;
-+ int i;
-+ u8 ack;
-+ u64 rn;
-+ struct w1_reg_num *reg_num;
-+ int seq = 0;
-+
-+ mutex_lock(&sl->master->bus_mutex);
-+ /* Place all devices in CHAIN state */
-+ if (w1_reset_bus(sl->master))
-+ goto error;
-+ w1_write_8(sl->master, W1_SKIP_ROM);
-+ w1_write_8(sl->master, W1_42_CHAIN);
-+ w1_write_8(sl->master, W1_42_CHAIN_ON);
-+ w1_write_8(sl->master, W1_42_CHAIN_ON_INV);
-+ msleep(sl->master->pullup_duration);
-+
-+ /* check for acknowledgment */
-+ ack = w1_read_8(sl->master);
-+ if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
-+ goto error;
-+
-+ /* In case the bus fails to send 0xFF, limit*/
-+ for (i = 0; i <= 64; i++) {
-+ if (w1_reset_bus(sl->master))
-+ goto error;
-+
-+ w1_write_8(sl->master, W1_42_COND_READ);
-+ rv = w1_read_block(sl->master, (u8 *)&rn, 8);
-+ reg_num = (struct w1_reg_num *) &rn;
-+ if (reg_num->family == W1_42_FINISHED_BYTE)
-+ break;
-+ if (sl->reg_num.id == reg_num->id)
-+ seq = i;
-+
-+ w1_write_8(sl->master, W1_42_CHAIN);
-+ w1_write_8(sl->master, W1_42_CHAIN_DONE);
-+ w1_write_8(sl->master, W1_42_CHAIN_DONE_INV);
-+ w1_read_block(sl->master, &ack, sizeof(ack));
-+
-+ /* check for acknowledgment */
-+ ack = w1_read_8(sl->master);
-+ if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
-+ goto error;
-+
-+ }
-+
-+ /* Exit from CHAIN state */
-+ if (w1_reset_bus(sl->master))
-+ goto error;
-+ w1_write_8(sl->master, W1_SKIP_ROM);
-+ w1_write_8(sl->master, W1_42_CHAIN);
-+ w1_write_8(sl->master, W1_42_CHAIN_OFF);
-+ w1_write_8(sl->master, W1_42_CHAIN_OFF_INV);
-+
-+ /* check for acknowledgment */
-+ ack = w1_read_8(sl->master);
-+ if (ack != W1_42_SUCCESS_CONFIRM_BYTE)
-+ goto error;
-+ mutex_unlock(&sl->master->bus_mutex);
-+
-+ c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", seq);
-+ return PAGE_SIZE - c;
-+error:
-+ mutex_unlock(&sl->master->bus_mutex);
-+ return -EIO;
-+}
-+
- static int __init w1_therm_init(void)
- {
- int err, i;
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