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authorYunhong Jiang <yunhong.jiang@linux.intel.com>2017-03-08 23:13:28 -0800
committerYunhong Jiang <yunhong.jiang@linux.intel.com>2017-03-08 23:36:15 -0800
commit52f993b8e89487ec9ee15a7fb4979e0f09a45b27 (patch)
treed65304486afe0bea4a311c783c0d72791c8c0aa2 /kernel/drivers/hwmon/ads7828.c
parentc189ccac5702322ed843fe17057035b7222a59b6 (diff)
Upgrade to 4.4.50-rt62
The current kernel is based on rt kernel v4.4.6-rt14. We will upgrade it to 4.4.50-rt62. The command to achieve it is: a) Clone a git repo from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-stable-rt.git b) Get the diff between this two changesets: git diff 640eca2901f3435e616157b11379d3223a44b391 705619beeea1b0b48219a683fd1a901a86fdaf5e where the two commits are: [yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only 640eca2901f3435e616157b11379d3223a44b391 640eca2901f3 v4.4.6-rt14 localversion-rt [yjiang5@jnakajim-build linux-stable-rt]$ git show --oneline --name-only 705619beeea1b0b48219a683fd1a901a86fdaf5e 705619beeea1 Linux 4.4.50-rt62 localversion-rt c) One patch has been backported thus revert the patch before applying. filterdiff -p1 -x scripts/package/Makefile ~/tmp/v4.4.6-rt14-4.4.50-rt62.diff |patch -p1 --dry-run Upstream status: backport Change-Id: I244d57a32f6066e5a5b9915f9fbf99e7bbca6e01 Signed-off-by: Yunhong Jiang <yunhong.jiang@linux.intel.com>
Diffstat (limited to 'kernel/drivers/hwmon/ads7828.c')
-rw-r--r--kernel/drivers/hwmon/ads7828.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/kernel/drivers/hwmon/ads7828.c b/kernel/drivers/hwmon/ads7828.c
index 6c99ee7ba..ee396ff16 100644
--- a/kernel/drivers/hwmon/ads7828.c
+++ b/kernel/drivers/hwmon/ads7828.c
@@ -120,6 +120,7 @@ static int ads7828_probe(struct i2c_client *client,
unsigned int vref_mv = ADS7828_INT_VREF_MV;
bool diff_input = false;
bool ext_vref = false;
+ unsigned int regval;
data = devm_kzalloc(dev, sizeof(struct ads7828_data), GFP_KERNEL);
if (!data)
@@ -154,6 +155,15 @@ static int ads7828_probe(struct i2c_client *client,
if (!diff_input)
data->cmd_byte |= ADS7828_CMD_SD_SE;
+ /*
+ * Datasheet specifies internal reference voltage is disabled by
+ * default. The internal reference voltage needs to be enabled and
+ * voltage needs to settle before getting valid ADC data. So perform a
+ * dummy read to enable the internal reference voltage.
+ */
+ if (!ext_vref)
+ regmap_read(data->regmap, data->cmd_byte, &regval);
+
hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
data,
ads7828_groups);