Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965214Ab3GSHn6 (ORCPT ); Fri, 19 Jul 2013 03:43:58 -0400 Received: from hqemgate03.nvidia.com ([216.228.121.140]:12554 "EHLO hqemgate03.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753189Ab3GSHnu (ORCPT ); Fri, 19 Jul 2013 03:43:50 -0400 X-PGP-Universal: processed; by hqnvupgp07.nvidia.com on Fri, 19 Jul 2013 00:43:30 -0700 Message-ID: <51E8EE21.1070803@nvidia.com> Date: Fri, 19 Jul 2013 15:43:29 +0800 From: Wei Ni User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130623 Thunderbird/17.0.7 MIME-Version: 1.0 To: Eduardo Valentin CC: "devicetree-discuss@lists.ozlabs.org" , "l.stach@pengutronix.de" , "linux-kernel@vger.kernel.org" , "linux-pm@vger.kernel.org" , "lm-sensors@lm-sensors.org" , Jean Delvare , Guenter Roeck Subject: Re: [RESEND PATCH V1 8/9] hwmon: lm75: expose to thermal fw via DT nodes References: <1374074248-31690-1-git-send-email-eduardo.valentin@ti.com> <1374074248-31690-9-git-send-email-eduardo.valentin@ti.com> <51E77E1D.3000306@nvidia.com> <51E7E9A1.3040800@ti.com> In-Reply-To: <51E7E9A1.3040800@ti.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5811 Lines: 183 On 07/18/2013 09:12 PM, Eduardo Valentin wrote: > * PGP Signed: 07/18/2013 at 06:12:01 AM > > Hi Wei, > > > On 18-07-2013 01:33, Wei Ni wrote: >> On 07/17/2013 11:17 PM, Eduardo Valentin wrote: >>> This patch adds to lm75 temperature sensor the possibility >>> to expose itself as thermal zone device, registered on the >>> thermal framework. >>> >>> The thermal zone is built only if a device tree node >>> describing a thermal zone for this sensor is present >>> inside the lm75 DT node. Otherwise, the driver behavior >>> will be the same. >>> >>> Cc: Jean Delvare >>> Cc: Guenter Roeck >>> Cc: lm-sensors@lm-sensors.org >>> Cc: linux-kernel@vger.kernel.org >>> Signed-off-by: Eduardo Valentin >>> --- >>> drivers/hwmon/lm75.c | 29 +++++++++++++++++++++++++++++ >>> 1 file changed, 29 insertions(+) >>> >>> diff --git a/drivers/hwmon/lm75.c b/drivers/hwmon/lm75.c >>> index c03b490..0aa5e28 100644 >>> --- a/drivers/hwmon/lm75.c >>> +++ b/drivers/hwmon/lm75.c >>> @@ -27,6 +27,8 @@ >>> #include >>> #include >>> #include >>> +#include >>> +#include >>> #include "lm75.h" >>> >>> >>> @@ -70,6 +72,7 @@ static const u8 LM75_REG_TEMP[3] = { >>> /* Each client has this additional data */ >>> struct lm75_data { >>> struct device *hwmon_dev; >>> + struct thermal_zone_device *tz; >>> struct mutex update_lock; >>> u8 orig_conf; >>> u8 resolution; /* In bits, between 9 and 12 */ >>> @@ -92,6 +95,19 @@ static struct lm75_data *lm75_update_device(struct device *dev); >>> >>> /* sysfs attributes for hwmon */ >>> >>> +static int lm75_read_temp(void *dev, unsigned long *temp) >>> +{ >>> + struct lm75_data *data = lm75_update_device(dev); >>> + >>> + if (IS_ERR(data)) >>> + return PTR_ERR(data); >>> + >>> + *temp = ((data->temp[0] >> (16 - data->resolution)) * 1000) >> >>> + (data->resolution - 8); >>> + >>> + return 0; >>> +} >>> + >>> static ssize_t show_temp(struct device *dev, struct device_attribute *da, >>> char *buf) >>> { >>> @@ -271,11 +287,23 @@ lm75_probe(struct i2c_client *client, const struct i2c_device_id *id) >>> goto exit_remove; >>> } >>> >>> + if (of_find_node_by_name(client->dev.of_node, "thermal_zone")) { >>> + data->tz = thermal_zone_of_device_register(&client->dev, >>> + &client->dev, >>> + lm75_read_temp); >> >> Hi, Eduardo >> I have two questions: >> 1. As we know, after register to the thermal framework, it will have >> duplicate hwmon devices. I think lm-sensor maintainer would not like this. > > Yes I noticed. You have always the option to disable the > CONFIG_THERMAL_HWMON in your build. Yes, we can disable this config, but it will disable all hwmon interface which registered by the thermal fw, it may affect other driver. > >> How about to add a flag to indicate it, which I talk about with >> Durgadoss in your [RFC 1/4]patch. > > This would be very much appreciated, but I don't think this is a blocker > for this series. We can of course include this patch on it. Having a > flag to control this thermal fw to hwmon interface is actually a good idea. Ok, I think I can post it as a separate patches. > >> >> 2. I'm also trying to use your codes on lm90. The LM90 serial has more >> then one sensors in one chip, local sensor, remote sensor and may have >> remote2 sensor, so it mean there may have more than one thermal_zone >> under the lm90 device node, will you consider it? >> > > I haven't looked lm90 source code. How do you map it? Do you probe each > sensor or do you probe 1 device and expose 3 sensors? lm90.c is the driver for all LM90 register compatible chips, it probe 1 device, and normally it can expose local and remote sensor, and for max669x chip, it also expose remote2 sensor. > > In first case, you can still reuse what is in this series. > > Later case, we need to change it slightly. > > That is the case which is pretty similar on OMAP5 for instance, where > the device has three sensors. This patch series does not cover for this > case. But it can be simply modified to get around it. > > We would need to allow more than one 'thermal_zone' nodes inside a > single device. But then we would need to have a way to determine which > sensor goes to which zone too. Yes, agreed, we need a way to determine it. I have tentative suggestions, how about following: lm90 { ... thermal_zone@0 { type = "local_sensor"; ... } thermal_zone@1 { type = "remote_sensor"; } } And in the driver's probe routine, we can parse the thermal_zone node, and pass it to thermal_zone_of_device_register() with the right .get_temp(). Wei. > > >> Thanks. >> Wei. >> >>> + if (IS_ERR(data->tz)) { >>> + status = PTR_ERR(data->tz); >>> + goto exit_hwmon; >>> + } >>> + } >>> + >>> dev_info(&client->dev, "%s: sensor '%s'\n", >>> dev_name(data->hwmon_dev), client->name); >>> >>> return 0; >>> >>> +exit_hwmon: >>> + hwmon_device_unregister(data->hwmon_dev); >>> exit_remove: >>> sysfs_remove_group(&client->dev.kobj, &lm75_group); >>> return status; >>> @@ -285,6 +313,7 @@ static int lm75_remove(struct i2c_client *client) >>> { >>> struct lm75_data *data = i2c_get_clientdata(client); >>> >>> + thermal_zone_device_unregister(data->tz); >>> hwmon_device_unregister(data->hwmon_dev); >>> sysfs_remove_group(&client->dev.kobj, &lm75_group); >>> lm75_write_value(client, LM75_REG_CONF, data->orig_conf); >>> >> >> >> > > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/