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-rw-r--r--Documentation/ABI/stable/sysfs-driver-w1_ds24386
-rw-r--r--Documentation/w1/slaves/w1_ds2438.rst8
-rw-r--r--drivers/w1/slaves/w1_ds2438.c41
3 files changed, 55 insertions, 0 deletions
diff --git a/Documentation/ABI/stable/sysfs-driver-w1_ds2438 b/Documentation/ABI/stable/sysfs-driver-w1_ds2438
new file mode 100644
index 000000000000..fa47437c11d9
--- /dev/null
+++ b/Documentation/ABI/stable/sysfs-driver-w1_ds2438
@@ -0,0 +1,6 @@
+What: /sys/bus/w1/devices/.../page1
+Date: April 2021
+Contact: Luiz Sampaio <sampaio.ime@gmail.com>
+Description: read the contents of the page1 of the DS2438
+ see Documentation/w1/slaves/w1_ds2438.rst for detailed information
+Users: any user space application which wants to communicate with DS2438
diff --git a/Documentation/w1/slaves/w1_ds2438.rst b/Documentation/w1/slaves/w1_ds2438.rst
index a29309a3f8e5..ac8d0d4b0d0e 100644
--- a/Documentation/w1/slaves/w1_ds2438.rst
+++ b/Documentation/w1/slaves/w1_ds2438.rst
@@ -44,6 +44,14 @@ Internally when this file is read, the additional CRC byte is also obtained
from the slave device. If it is correct, the 8 bytes page data are passed
to userspace, otherwise an I/O error is returned.
+"page1"
+-------
+This file provides full 8 bytes of the chip Page 1 (01h).
+This page contains the ICA, elapsed time meter and current offset data of the DS2438.
+Internally when this file is read, the additional CRC byte is also obtained
+from the slave device. If it is correct, the 8 bytes page data are passed
+to userspace, otherwise an I/O error is returned.
+
"temperature"
-------------
Opening and reading this file initiates the CONVERT_T (temperature conversion)
diff --git a/drivers/w1/slaves/w1_ds2438.c b/drivers/w1/slaves/w1_ds2438.c
index 1e95f3a256c7..42080ae779f0 100644
--- a/drivers/w1/slaves/w1_ds2438.c
+++ b/drivers/w1/slaves/w1_ds2438.c
@@ -49,6 +49,15 @@
#define DS2438_CURRENT_MSB 0x06
#define DS2438_THRESHOLD 0x07
+/* Page #1 definitions */
+#define DS2438_ETM_0 0x00
+#define DS2438_ETM_1 0x01
+#define DS2438_ETM_2 0x02
+#define DS2438_ETM_3 0x03
+#define DS2438_ICA 0x04
+#define DS2438_OFFSET_LSB 0x05
+#define DS2438_OFFSET_MSB 0x06
+
static int w1_ds2438_get_page(struct w1_slave *sl, int pageno, u8 *buf)
{
unsigned int retries = W1_DS2438_RETRIES;
@@ -325,6 +334,36 @@ static ssize_t page0_read(struct file *filp, struct kobject *kobj,
return ret;
}
+static ssize_t page1_read(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr, char *buf,
+ loff_t off, size_t count)
+{
+ struct w1_slave *sl = kobj_to_w1_slave(kobj);
+ int ret;
+ u8 w1_buf[DS2438_PAGE_SIZE + 1 /*for CRC*/];
+
+ if (off != 0)
+ return 0;
+ if (!buf)
+ return -EINVAL;
+
+ mutex_lock(&sl->master->bus_mutex);
+
+ /* Read no more than page1 size */
+ if (count > DS2438_PAGE_SIZE)
+ count = DS2438_PAGE_SIZE;
+
+ if (w1_ds2438_get_page(sl, 1, w1_buf) == 0) {
+ memcpy(buf, &w1_buf, count);
+ ret = count;
+ } else
+ ret = -EIO;
+
+ mutex_unlock(&sl->master->bus_mutex);
+
+ return ret;
+}
+
static ssize_t temperature_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr, char *buf,
loff_t off, size_t count)
@@ -390,6 +429,7 @@ static ssize_t vdd_read(struct file *filp, struct kobject *kobj,
static BIN_ATTR_RW(iad, 0);
static BIN_ATTR_RO(page0, DS2438_PAGE_SIZE);
+static BIN_ATTR_RO(page1, DS2438_PAGE_SIZE);
static BIN_ATTR_RO(temperature, 0/* real length varies */);
static BIN_ATTR_RO(vad, 0/* real length varies */);
static BIN_ATTR_RO(vdd, 0/* real length varies */);
@@ -397,6 +437,7 @@ static BIN_ATTR_RO(vdd, 0/* real length varies */);
static struct bin_attribute *w1_ds2438_bin_attrs[] = {
&bin_attr_iad,
&bin_attr_page0,
+ &bin_attr_page1,
&bin_attr_temperature,
&bin_attr_vad,
&bin_attr_vdd,