From: Julien Folly julien.folly@gmail.com
[ Upstream commit 6eaafbb6998e999467cf78a76e155ee00e372b14 ]
IAD Register is yet readable trough the "iad" sys file.
A write to the "iad" sys file enables or disables the current measurement, but it was not possible to get the measured value by reading it. Fix: %u in snprintf for unsigned values (vdd and vad) Fix: Avoid possibles overflows (Usage of the 'count' variables)
Signed-off-by: Julien Folly julien.folly@gmail.com Acked-by: Evgeniy Polyakov zbr@ioremap.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/w1/slaves/w1_ds2438.c | 66 +++++++++++++++++++++++++++-------- 1 file changed, 52 insertions(+), 14 deletions(-)
diff --git a/drivers/w1/slaves/w1_ds2438.c b/drivers/w1/slaves/w1_ds2438.c index bf641a191d077..7c4e33dbee4d5 100644 --- a/drivers/w1/slaves/w1_ds2438.c +++ b/drivers/w1/slaves/w1_ds2438.c @@ -186,8 +186,8 @@ static int w1_ds2438_change_config_bit(struct w1_slave *sl, u8 mask, u8 value) return -1; }
-static uint16_t w1_ds2438_get_voltage(struct w1_slave *sl, - int adc_input, uint16_t *voltage) +static int w1_ds2438_get_voltage(struct w1_slave *sl, + int adc_input, uint16_t *voltage) { unsigned int retries = W1_DS2438_RETRIES; u8 w1_buf[DS2438_PAGE_SIZE + 1 /*for CRC*/]; @@ -235,6 +235,25 @@ static uint16_t w1_ds2438_get_voltage(struct w1_slave *sl, return ret; }
+static int w1_ds2438_get_current(struct w1_slave *sl, int16_t *voltage) +{ + u8 w1_buf[DS2438_PAGE_SIZE + 1 /*for CRC*/]; + int ret; + + mutex_lock(&sl->master->bus_mutex); + + if (w1_ds2438_get_page(sl, 0, w1_buf) == 0) { + /* The voltage measured across current sense resistor RSENS. */ + *voltage = (((int16_t) w1_buf[DS2438_CURRENT_MSB]) << 8) | ((int16_t) w1_buf[DS2438_CURRENT_LSB]); + ret = 0; + } else + ret = -1; + + mutex_unlock(&sl->master->bus_mutex); + + return ret; +} + static ssize_t iad_write(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) @@ -257,6 +276,27 @@ static ssize_t iad_write(struct file *filp, struct kobject *kobj, return ret; }
+static ssize_t iad_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; + int16_t voltage; + + if (off != 0) + return 0; + if (!buf) + return -EINVAL; + + if (w1_ds2438_get_current(sl, &voltage) == 0) { + ret = snprintf(buf, count, "%i\n", voltage); + } else + ret = -EIO; + + return ret; +} + static ssize_t page0_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buf, loff_t off, size_t count) @@ -272,9 +312,13 @@ static ssize_t page0_read(struct file *filp, struct kobject *kobj,
mutex_lock(&sl->master->bus_mutex);
+ /* Read no more than page0 size */ + if (count > DS2438_PAGE_SIZE) + count = DS2438_PAGE_SIZE; + if (w1_ds2438_get_page(sl, 0, w1_buf) == 0) { - memcpy(buf, &w1_buf, DS2438_PAGE_SIZE); - ret = DS2438_PAGE_SIZE; + memcpy(buf, &w1_buf, count); + ret = count; } else ret = -EIO;
@@ -289,7 +333,6 @@ static ssize_t temperature_read(struct file *filp, struct kobject *kobj, { struct w1_slave *sl = kobj_to_w1_slave(kobj); int ret; - ssize_t c = PAGE_SIZE; int16_t temp;
if (off != 0) @@ -298,8 +341,7 @@ static ssize_t temperature_read(struct file *filp, struct kobject *kobj, return -EINVAL;
if (w1_ds2438_get_temperature(sl, &temp) == 0) { - c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", temp); - ret = PAGE_SIZE - c; + ret = snprintf(buf, count, "%i\n", temp); } else ret = -EIO;
@@ -312,7 +354,6 @@ static ssize_t vad_read(struct file *filp, struct kobject *kobj, { struct w1_slave *sl = kobj_to_w1_slave(kobj); int ret; - ssize_t c = PAGE_SIZE; uint16_t voltage;
if (off != 0) @@ -321,8 +362,7 @@ static ssize_t vad_read(struct file *filp, struct kobject *kobj, return -EINVAL;
if (w1_ds2438_get_voltage(sl, DS2438_ADC_INPUT_VAD, &voltage) == 0) { - c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", voltage); - ret = PAGE_SIZE - c; + ret = snprintf(buf, count, "%u\n", voltage); } else ret = -EIO;
@@ -335,7 +375,6 @@ static ssize_t vdd_read(struct file *filp, struct kobject *kobj, { struct w1_slave *sl = kobj_to_w1_slave(kobj); int ret; - ssize_t c = PAGE_SIZE; uint16_t voltage;
if (off != 0) @@ -344,15 +383,14 @@ static ssize_t vdd_read(struct file *filp, struct kobject *kobj, return -EINVAL;
if (w1_ds2438_get_voltage(sl, DS2438_ADC_INPUT_VDD, &voltage) == 0) { - c -= snprintf(buf + PAGE_SIZE - c, c, "%d\n", voltage); - ret = PAGE_SIZE - c; + ret = snprintf(buf, count, "%u\n", voltage); } else ret = -EIO;
return ret; }
-static BIN_ATTR(iad, S_IRUGO | S_IWUSR | S_IWGRP, NULL, iad_write, 1); +static BIN_ATTR(iad, S_IRUGO | S_IWUSR | S_IWGRP, iad_read, iad_write, 0); static BIN_ATTR_RO(page0, DS2438_PAGE_SIZE); static BIN_ATTR_RO(temperature, 0/* real length varies */); static BIN_ATTR_RO(vad, 0/* real length varies */);