From: Guenter Roeck <linux@roeck-us.net>
To: Neelesh Gupta <neelegup@linux.vnet.ibm.com>, jdelvare@suse.de
Cc: benh@au1.ibm.com, linux-kernel@vger.kernel.org,
michaele@au1.ibm.com, lm-sensors@lm-sensors.org
Subject: Re: [PATCH] hwmon: (ibmpowernv) Use platform 'id_table' to probe the device
Date: Tue, 04 Nov 2014 06:28:36 -0800 [thread overview]
Message-ID: <5458E294.40509@roeck-us.net> (raw)
In-Reply-To: <20141104072927.4307.67881.stgit@localhost.localdomain>
On 11/03/2014 11:30 PM, Neelesh Gupta wrote:
> The current driver probe() function assumes the sensor device to be
> alwary present and gets executed every time if the driver is loaded,
> but the appropriate hardware could not be present.
>
> So, move the platform device creation as part of platform init code
> and use the 'id_table' to check if the device present or not.
>
> Signed-off-by: Neelesh Gupta <neelegup@linux.vnet.ibm.com>
> ---
> arch/powerpc/platforms/powernv/opal-sensor.c | 20 ++++++++
> drivers/hwmon/ibmpowernv.c | 67 +++++++-------------------
> 2 files changed, 39 insertions(+), 48 deletions(-)
>
> diff --git a/arch/powerpc/platforms/powernv/opal-sensor.c b/arch/powerpc/platforms/powernv/opal-sensor.c
> index 10271ad..215c418 100644
> --- a/arch/powerpc/platforms/powernv/opal-sensor.c
> +++ b/arch/powerpc/platforms/powernv/opal-sensor.c
> @@ -20,7 +20,9 @@
>
> #include <linux/delay.h>
> #include <linux/mutex.h>
> +#include <linux/of_platform.h>
> #include <asm/opal.h>
> +#include <asm/machdep.h>
>
> static DEFINE_MUTEX(opal_sensor_mutex);
>
> @@ -64,3 +66,21 @@ out:
> return ret;
> }
> EXPORT_SYMBOL_GPL(opal_get_sensor_data);
> +
> +static __init int opal_sensor_init(void)
> +{
> + struct platform_device *pdev;
> + struct device_node *sensor;
> +
> + sensor = of_find_node_by_path("/ibm,opal/sensors");
> + if (sensor) {
> + pdev = of_platform_device_create(sensor, "opal-sensor", NULL);
> + of_node_put(sensor);
> + } else {
> + pr_info("Opal node 'sensors' not found\n");
Hi Neelesh,
this is either an error and should be reported with pr_err, or it is
a valid condition and should be reported with pr_debug or not at all.
Which one is it ?
Also, can you put this code into a 'normal' error handler instead of using if/else ?
if (!sensor) {
pr_err("Opal node 'sensors' not found\n");
return -ENODEV;
}
pdev = of_platform_device_create(sensor, "opal-sensor", NULL);
...
This would make the code flow easier to understand.
Thanks,
Guenter
> + return -ENODEV;
> + }
> +
> + return PTR_ERR_OR_ZERO(pdev);
> +}
> +machine_subsys_initcall(powernv, opal_sensor_init);
> diff --git a/drivers/hwmon/ibmpowernv.c b/drivers/hwmon/ibmpowernv.c
> index 6a30eee..c7577b8 100644
> --- a/drivers/hwmon/ibmpowernv.c
> +++ b/drivers/hwmon/ibmpowernv.c
> @@ -74,9 +74,6 @@ struct platform_data {
> u32 sensors_count; /* Total count of sensors from each group */
> };
>
> -/* Platform device representing all the ibmpowernv sensors */
> -static struct platform_device *pdevice;
> -
> static ssize_t show_sensor(struct device *dev, struct device_attribute *devattr,
> char *buf)
> {
> @@ -99,7 +96,7 @@ static ssize_t show_sensor(struct device *dev, struct device_attribute *devattr,
> return sprintf(buf, "%u\n", x);
> }
>
> -static int __init get_sensor_index_attr(const char *name, u32 *index,
> +static int get_sensor_index_attr(const char *name, u32 *index,
> char *attr)
> {
> char *hash_pos = strchr(name, '#');
> @@ -136,7 +133,7 @@ static int __init get_sensor_index_attr(const char *name, u32 *index,
> * which need to be mapped as fan2_input, temp1_max respectively before
> * populating them inside hwmon device class.
> */
> -static int __init create_hwmon_attr_name(struct device *dev, enum sensors type,
> +static int create_hwmon_attr_name(struct device *dev, enum sensors type,
> const char *node_name,
> char *hwmon_attr_name)
> {
> @@ -172,7 +169,7 @@ static int __init create_hwmon_attr_name(struct device *dev, enum sensors type,
> return 0;
> }
>
> -static int __init populate_attr_groups(struct platform_device *pdev)
> +static int populate_attr_groups(struct platform_device *pdev)
> {
> struct platform_data *pdata = platform_get_drvdata(pdev);
> const struct attribute_group **pgroups = pdata->attr_groups;
> @@ -180,11 +177,6 @@ static int __init populate_attr_groups(struct platform_device *pdev)
> enum sensors type;
>
> opal = of_find_node_by_path("/ibm,opal/sensors");
> - if (!opal) {
> - dev_dbg(&pdev->dev, "Opal node 'sensors' not found\n");
> - return -ENODEV;
> - }
> -
> for_each_child_of_node(opal, np) {
> if (np->name == NULL)
> continue;
> @@ -221,7 +213,7 @@ static int __init populate_attr_groups(struct platform_device *pdev)
> * to the name required by the higher 'hwmon' driver like fan1_input, temp1_max
> * etc..
> */
> -static int __init create_device_attrs(struct platform_device *pdev)
> +static int create_device_attrs(struct platform_device *pdev)
> {
> struct platform_data *pdata = platform_get_drvdata(pdev);
> const struct attribute_group **pgroups = pdata->attr_groups;
> @@ -280,7 +272,7 @@ exit_put_node:
> return err;
> }
>
> -static int __init ibmpowernv_probe(struct platform_device *pdev)
> +static int ibmpowernv_probe(struct platform_device *pdev)
> {
> struct platform_data *pdata;
> struct device *hwmon_dev;
> @@ -309,52 +301,31 @@ static int __init ibmpowernv_probe(struct platform_device *pdev)
> return PTR_ERR_OR_ZERO(hwmon_dev);
> }
>
> +static const struct platform_device_id opal_sensor_driver_ids[] = {
> + {
> + .name = "opal-sensor",
> + },
> + { }
> +};
> +MODULE_DEVICE_TABLE(platform, opal_sensor_driver_ids);
> +
> static struct platform_driver ibmpowernv_driver = {
> - .driver = {
> - .owner = THIS_MODULE,
> - .name = DRVNAME,
> + .probe = ibmpowernv_probe,
> + .id_table = opal_sensor_driver_ids,
> + .driver = {
> + .owner = THIS_MODULE,
> + .name = DRVNAME,
> },
> };
>
> static int __init ibmpowernv_init(void)
> {
> - int err;
> -
> - pdevice = platform_device_alloc(DRVNAME, 0);
> - if (!pdevice) {
> - pr_err("Device allocation failed\n");
> - err = -ENOMEM;
> - goto exit;
> - }
> -
> - err = platform_device_add(pdevice);
> - if (err) {
> - pr_err("Device addition failed (%d)\n", err);
> - goto exit_device_put;
> - }
> -
> - err = platform_driver_probe(&ibmpowernv_driver, ibmpowernv_probe);
> - if (err) {
> - if (err != -ENODEV)
> - pr_err("Platform driver probe failed (%d)\n", err);
> -
> - goto exit_device_del;
> - }
> -
> - return 0;
> -
> -exit_device_del:
> - platform_device_del(pdevice);
> -exit_device_put:
> - platform_device_put(pdevice);
> -exit:
> - return err;
> + return platform_driver_register(&ibmpowernv_driver);
> }
>
> static void __exit ibmpowernv_exit(void)
> {
> platform_driver_unregister(&ibmpowernv_driver);
> - platform_device_unregister(pdevice);
> }
>
> MODULE_AUTHOR("Neelesh Gupta <neelegup@linux.vnet.ibm.com>");
>
>
next prev parent reply other threads:[~2014-11-04 14:29 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-04 7:30 [PATCH] hwmon: (ibmpowernv) Use platform 'id_table' to probe the device Neelesh Gupta
2014-11-04 14:28 ` Guenter Roeck [this message]
2014-11-04 21:16 ` Neelesh Gupta
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=5458E294.40509@roeck-us.net \
--to=linux@roeck-us.net \
--cc=benh@au1.ibm.com \
--cc=jdelvare@suse.de \
--cc=linux-kernel@vger.kernel.org \
--cc=lm-sensors@lm-sensors.org \
--cc=michaele@au1.ibm.com \
--cc=neelegup@linux.vnet.ibm.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).