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Message-Id: <20160906131643.1930011-1-arnd@arndb.de>
Date: Tue, 6 Sep 2016 15:16:33 +0200
From: Arnd Bergmann <arnd@...db.de>
To: Sebastian Reichel <sre@...nel.org>
Cc: Phil Reid <preid@...ctromag.com.au>, Arnd Bergmann <arnd@...db.de>,
YH Huang <yh.huang@...iatek.com>,
Joshua Clayton <stillcompiling@...il.com>,
linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] power: supply: sbs-battery: simplify DT parsing
After the change to use the gpio descriptor interface, we get a warning if
-Wmaybe-uninitialized is added back to the build flags (it is currently
disabled:
drivers/power/supply/sbs-battery.c: In function 'sbs_probe':
drivers/power/supply/sbs-battery.c:760:28: error: 'pdata' may be used uninitialized in this function [-Werror=maybe-uninitialized]
The problem is that if neither the DT properties nor a platform_data
pointer are provided, the chip->pdata pointer gets set to an uninitialized
value.
Looking at the code some more, I found that the sbs_of_populate_pdata
function is more complex than necessary and has confusing calling
conventions of possibly returning a valid pointer, a NULL pointer
or an ERR_PTR pointer (in addition to the uninitialized pointer).
To fix all of that, this gets rid of the chip->pdata pointer and
simply moves the two integers into the sbs_info structure. This
makes it much clearer from reading sbs_probe() what the precedence
of the three possible values are (pdata, DT, hardcoded defaults)
and completely avoids the #ifdef CONFIG_OF guards as
of_property_read_u32() gets replaced with a compile-time stub
when that is disabled, and returns an error if passed a NULL of_node
pointer.
Signed-off-by: Arnd Bergmann <arnd@...db.de>
Fixes: 3b5dd3a49496 ("power: supply: sbs-battery: Use gpio_desc and sleeping calls for battery detect")
---
drivers/power/supply/sbs-battery.c | 98 ++++++++++++--------------------------
1 file changed, 31 insertions(+), 67 deletions(-)
diff --git a/drivers/power/supply/sbs-battery.c b/drivers/power/supply/sbs-battery.c
index 8b4c6a8681b0..248a5dd75e22 100644
--- a/drivers/power/supply/sbs-battery.c
+++ b/drivers/power/supply/sbs-battery.c
@@ -169,6 +169,8 @@ struct sbs_info {
bool enable_detection;
int last_state;
int poll_time;
+ int i2c_retry_count;
+ int poll_retry_count;
struct delayed_work work;
int ignore_changes;
};
@@ -184,7 +186,7 @@ static int sbs_read_word_data(struct i2c_client *client, u8 address)
int retries = 1;
if (chip->pdata)
- retries = max(chip->pdata->i2c_retry_count + 1, 1);
+ retries = max(chip->i2c_retry_count + 1, 1);
while (retries > 0) {
ret = i2c_smbus_read_word_data(client, address);
@@ -212,8 +214,8 @@ static int sbs_read_string_data(struct i2c_client *client, u8 address,
u8 block_buffer[I2C_SMBUS_BLOCK_MAX + 1];
if (chip->pdata) {
- retries_length = max(chip->pdata->i2c_retry_count + 1, 1);
- retries_block = max(chip->pdata->i2c_retry_count + 1, 1);
+ retries_length = max(chip->i2c_retry_count + 1, 1);
+ retries_block = max(chip->i2c_retry_count + 1, 1);
}
/* Adapter needs to support these two functions */
@@ -279,7 +281,7 @@ static int sbs_write_word_data(struct i2c_client *client, u8 address,
int retries = 1;
if (chip->pdata)
- retries = max(chip->pdata->i2c_retry_count + 1, 1);
+ retries = max(chip->i2c_retry_count + 1, 1);
while (retries > 0) {
ret = i2c_smbus_write_word_data(client, address,
@@ -741,61 +743,6 @@ static void sbs_delayed_work(struct work_struct *work)
}
}
-#if defined(CONFIG_OF)
-
-#include <linux/of_device.h>
-#include <linux/of_gpio.h>
-
-static const struct of_device_id sbs_dt_ids[] = {
- { .compatible = "sbs,sbs-battery" },
- { .compatible = "ti,bq20z75" },
- { }
-};
-MODULE_DEVICE_TABLE(of, sbs_dt_ids);
-
-static struct sbs_platform_data *sbs_of_populate_pdata(struct sbs_info *chip)
-{
- struct i2c_client *client = chip->client;
- struct device_node *of_node = client->dev.of_node;
- struct sbs_platform_data *pdata;
- int rc;
- u32 prop;
-
- /* verify this driver matches this device */
- if (!of_node)
- return NULL;
-
- /* first make sure at least one property is set, otherwise
- * it won't change behavior from running without pdata.
- */
- if (!of_get_property(of_node, "sbs,i2c-retry-count", NULL) &&
- !of_get_property(of_node, "sbs,poll-retry-count", NULL))
- goto of_out;
-
- pdata = devm_kzalloc(&client->dev, sizeof(struct sbs_platform_data),
- GFP_KERNEL);
- if (!pdata)
- return ERR_PTR(-ENOMEM);
-
- rc = of_property_read_u32(of_node, "sbs,i2c-retry-count", &prop);
- if (!rc)
- pdata->i2c_retry_count = prop;
-
- rc = of_property_read_u32(of_node, "sbs,poll-retry-count", &prop);
- if (!rc)
- pdata->poll_retry_count = prop;
-
-of_out:
- return pdata;
-}
-#else
-static struct sbs_platform_data *sbs_of_populate_pdata(
- struct sbs_info *client)
-{
- return ERR_PTR(-ENOSYS);
-}
-#endif
-
static const struct power_supply_desc sbs_default_desc = {
.type = POWER_SUPPLY_TYPE_BATTERY,
.properties = sbs_properties,
@@ -838,13 +785,23 @@ static int sbs_probe(struct i2c_client *client,
chip->ignore_changes = 1;
chip->last_state = POWER_SUPPLY_STATUS_UNKNOWN;
- if (!pdata)
- pdata = sbs_of_populate_pdata(chip);
-
- if (IS_ERR(pdata))
- return PTR_ERR(pdata);
-
- chip->pdata = pdata;
+ /* use pdata if available, fall back to DT properties,
+ * or hardcoded defaults if not
+ */
+ rc = of_property_read_u32(client->dev.of_node, "sbs,i2c-retry-count",
+ &chip->i2c_retry_count);
+ if (rc)
+ chip->i2c_retry_count = 1;
+
+ rc = of_property_read_u32(client->dev.of_node, "sbs,poll-retry-count",
+ &chip->poll_retry_count);
+ if (rc)
+ chip->poll_retry_count = 0;
+
+ if (pdata) {
+ chip->poll_retry_count = pdata->poll_retry_count;
+ chip->i2c_retry_count = pdata->i2c_retry_count;
+ }
chip->gpio_detect = devm_gpiod_get_optional(&client->dev,
"sbs,battery-detect", GPIOD_IN);
@@ -953,13 +910,20 @@ static const struct i2c_device_id sbs_id[] = {
};
MODULE_DEVICE_TABLE(i2c, sbs_id);
+static const struct of_device_id sbs_dt_ids[] = {
+ { .compatible = "sbs,sbs-battery" },
+ { .compatible = "ti,bq20z75" },
+ { }
+};
+MODULE_DEVICE_TABLE(of, sbs_dt_ids);
+
static struct i2c_driver sbs_battery_driver = {
.probe = sbs_probe,
.remove = sbs_remove,
.id_table = sbs_id,
.driver = {
.name = "sbs-battery",
- .of_match_table = of_match_ptr(sbs_dt_ids),
+ .of_match_table = sbs_dt_ids,
.pm = SBS_PM_OPS,
},
};
--
2.9.0
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