diff options
| author | Luiz Sampaio <sampaio.ime@gmail.com> | 2021-05-20 01:30:45 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-05-21 15:51:33 +0300 |
| commit | fd6ec5d79507f99639c94f107e8a98550c9e1cf6 (patch) | |
| tree | 6f2c945283a8a2c9e67e7b6968566d2099a0fac6 /drivers/w1/slaves | |
| parent | 1f5e7518f063728aee0679c5086b92d8ea429e11 (diff) | |
| download | linux-fd6ec5d79507f99639c94f107e8a98550c9e1cf6.tar.xz | |
w1: ds2438: adding support for reading page1
Added a sysfs entry to support reading the page1 registers. This registers
contain Elapsed Time Meter (ETM) data, which shows for how long the chip is
on, as well as an Offset Register data, which can be used to calibrate the
current measurement of the chip.
Signed-off-by: Luiz Sampaio <sampaio.ime@gmail.com>
Link: https://lore.kernel.org/r/20210519223046.13798-6-sampaio.ime@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/w1/slaves')
| -rw-r--r-- | drivers/w1/slaves/w1_ds2438.c | 41 |
1 files changed, 41 insertions, 0 deletions
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, |