| Message ID | 20230906084837.3043030-3-Delphine_CC_Chiu@wiwynn.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | hwmon: max31790: support to config PWM as TACH | expand |
On 9/6/23 01:48, Delphine CC Chiu wrote: > The PWM outputs of max31790 could be used as tachometer inputs by > setting the fan configuration register, but the driver doesn't support > to config the PWM outputs as tachometer inputs currently. > > Add a function to get properties of the setting of max31790 to config > PWM outputs as tachometer inputs before initializing max31790. > For example: set `pwm-as-tach = /bits/ 8 <2 5>` in DTS for max31790 and > the driver will config PWMOUT2 and PWMOUT5 as TACH8 and TACH11. > Devicetree properties have to be documented in a property file and have to be approved by a devicetree maintainer. Personally I don't think this is the proper way of configuring this, but I'll let devicetree maintainers decide. > Signed-off-by: Delphine CC Chiu <Delphine_CC_Chiu@wiwynn.com> > --- > drivers/hwmon/max31790.c | 50 ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 50 insertions(+) > > diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c > index 0cd44c1e998a..0f8fe911539b 100644 > --- a/drivers/hwmon/max31790.c > +++ b/drivers/hwmon/max31790.c > @@ -480,6 +480,52 @@ static const struct hwmon_chip_info max31790_chip_info = { > .info = max31790_info, > }; > > +static int max31790_config_pwm_as_tach(struct device *dev, > + struct i2c_client *client) > +{ > + struct device_node *np = dev->of_node; > + int i, ret = 0, size, channel; > + u8 pwm_index[NR_CHANNEL] = { 0 }; > + u8 fan_config; > + > + size = of_property_count_u8_elems(np, "pwm-as-tach"); > + > + if ((size > 0) && (size <= NR_CHANNEL)) { Please refrain from unnecessary ( ). > + ret = of_property_read_u8_array(np, "pwm-as-tach", pwm_index, > + size); > + if (ret) { > + dev_err(dev, > + "Property 'pwm-as-tach' cannot be read.\n"); > + return ret; > + } > + > + for (i = 0; i < size; i++) { > + if ((pwm_index[i] == 0) || > + (pwm_index[i] > NR_CHANNEL)) { > + continue; > + } Silently accepting bad data seems like a bad idea to me. > + > + channel = pwm_index[i] - 1; > + fan_config = i2c_smbus_read_byte_data( > + client, MAX31790_REG_FAN_CONFIG(channel)); > + if (fan_config < 0) { An u8 is never < 0 > + dev_err(dev, > + "Read fan config for channel %d failed.\n", > + channel); > + return fan_config; > + } > + > + fan_config |= (MAX31790_FAN_CFG_CTRL_MON | > + MAX31790_FAN_CFG_TACH_INPUT); This assumes that the channel is configured as pwm. What if the BIOS / ROMMON configured another channel which you want as pwm channel as fan input channel ? > + i2c_smbus_write_byte_data( > + client, MAX31790_REG_FAN_CONFIG(channel), > + fan_config); > + } > + } Silently ignoring errors seems like a bad idea. > + > + return 0; > +} > + > static int max31790_init_client(struct i2c_client *client, > struct max31790_data *data) > { > @@ -521,6 +567,10 @@ static int max31790_probe(struct i2c_client *client) > data->client = client; > mutex_init(&data->update_lock); > > + err = max31790_config_pwm_as_tach(dev, client); > + if (err) > + dev_crit(dev, "Config PWM as TACH failed.\n"); > + > /* > * Initialize the max31790 chip > */
Hi Delphine,
kernel test robot noticed the following build warnings:
[auto build test WARNING on groeck-staging/hwmon-next]
[also build test WARNING on linus/master v6.5 next-20230908]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]
url: https://github.com/intel-lab-lkp/linux/commits/Delphine-CC-Chiu/hwmon-max31790-support-to-config-PWM-as-TACH/20230906-165344
base: https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
patch link: https://lore.kernel.org/r/20230906084837.3043030-3-Delphine_CC_Chiu%40wiwynn.com
patch subject: [PATCH] hwmon: max31790: support to config PWM as TACH
config: x86_64-randconfig-161-20230907 (https://download.01.org/0day-ci/archive/20230909/202309090228.2bSFmAO8-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce: (https://download.01.org/0day-ci/archive/20230909/202309090228.2bSFmAO8-lkp@intel.com/reproduce)
If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202309090228.2bSFmAO8-lkp@intel.com/
smatch warnings:
drivers/hwmon/max31790.c:511 max31790_config_pwm_as_tach() warn: unsigned 'fan_config' is never less than zero.
vim +/fan_config +511 drivers/hwmon/max31790.c
482
483 static int max31790_config_pwm_as_tach(struct device *dev,
484 struct i2c_client *client)
485 {
486 struct device_node *np = dev->of_node;
487 int i, ret = 0, size, channel;
488 u8 pwm_index[NR_CHANNEL] = { 0 };
489 u8 fan_config;
490
491 size = of_property_count_u8_elems(np, "pwm-as-tach");
492
493 if ((size > 0) && (size <= NR_CHANNEL)) {
494 ret = of_property_read_u8_array(np, "pwm-as-tach", pwm_index,
495 size);
496 if (ret) {
497 dev_err(dev,
498 "Property 'pwm-as-tach' cannot be read.\n");
499 return ret;
500 }
501
502 for (i = 0; i < size; i++) {
503 if ((pwm_index[i] == 0) ||
504 (pwm_index[i] > NR_CHANNEL)) {
505 continue;
506 }
507
508 channel = pwm_index[i] - 1;
509 fan_config = i2c_smbus_read_byte_data(
510 client, MAX31790_REG_FAN_CONFIG(channel));
> 511 if (fan_config < 0) {
512 dev_err(dev,
513 "Read fan config for channel %d failed.\n",
514 channel);
515 return fan_config;
516 }
517
518 fan_config |= (MAX31790_FAN_CFG_CTRL_MON |
519 MAX31790_FAN_CFG_TACH_INPUT);
520 i2c_smbus_write_byte_data(
521 client, MAX31790_REG_FAN_CONFIG(channel),
522 fan_config);
523 }
524 }
525
526 return 0;
527 }
528
> -----Original Message----- > From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck > Sent: Thursday, September 7, 2023 12:20 AM > To: Delphine_CC_Chiu/WYHQ/Wiwynn <Delphine_CC_Chiu@wiwynn.com>; > patrick@stwcx.xyz; Jean Delvare <jdelvare@suse.com> > Cc: linux-hwmon@vger.kernel.org; linux-kernel@vger.kernel.org > Subject: Re: [PATCH] hwmon: max31790: support to config PWM as TACH > > Security Reminder: Please be aware that this email is sent by an external > sender. > > On 9/6/23 01:48, Delphine CC Chiu wrote: > > The PWM outputs of max31790 could be used as tachometer inputs by > > setting the fan configuration register, but the driver doesn't support > > to config the PWM outputs as tachometer inputs currently. > > > > Add a function to get properties of the setting of max31790 to config > > PWM outputs as tachometer inputs before initializing max31790. > > For example: set `pwm-as-tach = /bits/ 8 <2 5>` in DTS for max31790 > > and the driver will config PWMOUT2 and PWMOUT5 as TACH8 and > TACH11. > > > > Devicetree properties have to be documented in a property file and have to > be approved by a devicetree maintainer. > > Personally I don't think this is the proper way of configuring this, but I'll let > devicetree maintainers decide. > Thanks for your reply. We will add document of max31790 in v2 patch. > > Signed-off-by: Delphine CC Chiu <Delphine_CC_Chiu@wiwynn.com> > > --- > > drivers/hwmon/max31790.c | 50 > ++++++++++++++++++++++++++++++++++++++++ > > 1 file changed, 50 insertions(+) > > > > diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c > index > > 0cd44c1e998a..0f8fe911539b 100644 > > --- a/drivers/hwmon/max31790.c > > +++ b/drivers/hwmon/max31790.c > > @@ -480,6 +480,52 @@ static const struct hwmon_chip_info > max31790_chip_info = { > > .info = max31790_info, > > }; > > > > +static int max31790_config_pwm_as_tach(struct device *dev, > > + struct i2c_client *client) { > > + struct device_node *np = dev->of_node; > > + int i, ret = 0, size, channel; > > + u8 pwm_index[NR_CHANNEL] = { 0 }; > > + u8 fan_config; > > + > > + size = of_property_count_u8_elems(np, "pwm-as-tach"); > > + > > + if ((size > 0) && (size <= NR_CHANNEL)) { > > Please refrain from unnecessary ( ). > Will remove in the v2 patch. > > + ret = of_property_read_u8_array(np, "pwm-as-tach", > pwm_index, > > + size); > > + if (ret) { > > + dev_err(dev, > > + "Property 'pwm-as-tach' cannot be > read.\n"); > > + return ret; > > + } > > + > > + for (i = 0; i < size; i++) { > > + if ((pwm_index[i] == 0) || > > + (pwm_index[i] > NR_CHANNEL)) { > > + continue; > > + } > > Silently accepting bad data seems like a bad idea to me. > Add error handling in v2 patch. > > + > > + channel = pwm_index[i] - 1; > > + fan_config = i2c_smbus_read_byte_data( > > + client, > MAX31790_REG_FAN_CONFIG(channel)); > > + if (fan_config < 0) { > > An u8 is never < 0 > Use integer to get the return value first and set to fan_config in v2 patch. > > + dev_err(dev, > > + "Read fan config for channel > %d failed.\n", > > + channel); > > + return fan_config; > > + } > > + > > + fan_config |= > (MAX31790_FAN_CFG_CTRL_MON | > > + > MAX31790_FAN_CFG_TACH_INPUT); > > This assumes that the channel is configured as pwm. > What if the BIOS / ROMMON configured another channel which you want as > pwm channel as fan input channel ? > This will config the channel as TACH. Could you provide more information about the scenario you mentioned? In our system, there is only BMC that will set the config of fan device. > > + i2c_smbus_write_byte_data( > > + client, > MAX31790_REG_FAN_CONFIG(channel), > > + fan_config); > > + } > > + } > > Silently ignoring errors seems like a bad idea. > Add error handling in v2 patch. > > + > > + return 0; > > +} > > + > > static int max31790_init_client(struct i2c_client *client, > > struct max31790_data *data) > > { > > @@ -521,6 +567,10 @@ static int max31790_probe(struct i2c_client > *client) > > data->client = client; > > mutex_init(&data->update_lock); > > > > + err = max31790_config_pwm_as_tach(dev, client); > > + if (err) > > + dev_crit(dev, "Config PWM as TACH failed.\n"); > > + > > /* > > * Initialize the max31790 chip > > */
On 9/13/23 01:51, Delphine_CC_Chiu/WYHQ/Wiwynn wrote: [ ... ] >> >> This assumes that the channel is configured as pwm. >> What if the BIOS / ROMMON configured another channel which you want as >> pwm channel as fan input channel ? >> > This will config the channel as TACH. > Could you provide more information about the scenario you mentioned? > In our system, there is only BMC that will set the config of fan device. Please keep in mind that upstream code is not intended to only support your specific use case, but the use case of others as well. Your system (the one you have today) may only use the chip for fan speed measurement. Others may use it use it to control fans, or your hardware might tomorrow build another system where the chip us used to control the fans as well. Those use cases should be covered by your patch as well. Guenter
> -----Original Message----- > From: Guenter Roeck <groeck7@gmail.com> On Behalf Of Guenter Roeck > Sent: Wednesday, September 13, 2023 9:37 PM > To: Delphine_CC_Chiu/WYHQ/Wiwynn <Delphine_CC_Chiu@wiwynn.com>; > patrick@stwcx.xyz; Jean Delvare <jdelvare@suse.com> > Cc: linux-hwmon@vger.kernel.org; linux-kernel@vger.kernel.org > Subject: Re: [PATCH] hwmon: max31790: support to config PWM as TACH > > Security Reminder: Please be aware that this email is sent by an external > sender. > > On 9/13/23 01:51, Delphine_CC_Chiu/WYHQ/Wiwynn wrote: > > [ ... ] > > >> > >> This assumes that the channel is configured as pwm. > >> What if the BIOS / ROMMON configured another channel which you want > >> as pwm channel as fan input channel ? > >> > > This will config the channel as TACH. > > Could you provide more information about the scenario you mentioned? > > In our system, there is only BMC that will set the config of fan device. > > Please keep in mind that upstream code is not intended to only support your > specific use case, but the use case of others as well. Your system (the one you > have today) may only use the chip for fan speed measurement. Others may > use it use it to control fans, or your hardware might tomorrow build another > system where the chip us used to control the fans as well. Those use cases > should be covered by your patch as well. > > Guenter Hi Guenter, After our internal discussion, we thought that the PWM output channel of max31790 should either be PWM output or TACH input in hardware design. And the property "pwm-as-tach" is optional, if users don't want to config any PWM output channel as TACH input, then they don't need to add this property in DTS. Would like to know is this meet your expectations?
diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c index 0cd44c1e998a..0f8fe911539b 100644 --- a/drivers/hwmon/max31790.c +++ b/drivers/hwmon/max31790.c @@ -480,6 +480,52 @@ static const struct hwmon_chip_info max31790_chip_info = { .info = max31790_info, }; +static int max31790_config_pwm_as_tach(struct device *dev, + struct i2c_client *client) +{ + struct device_node *np = dev->of_node; + int i, ret = 0, size, channel; + u8 pwm_index[NR_CHANNEL] = { 0 }; + u8 fan_config; + + size = of_property_count_u8_elems(np, "pwm-as-tach"); + + if ((size > 0) && (size <= NR_CHANNEL)) { + ret = of_property_read_u8_array(np, "pwm-as-tach", pwm_index, + size); + if (ret) { + dev_err(dev, + "Property 'pwm-as-tach' cannot be read.\n"); + return ret; + } + + for (i = 0; i < size; i++) { + if ((pwm_index[i] == 0) || + (pwm_index[i] > NR_CHANNEL)) { + continue; + } + + channel = pwm_index[i] - 1; + fan_config = i2c_smbus_read_byte_data( + client, MAX31790_REG_FAN_CONFIG(channel)); + if (fan_config < 0) { + dev_err(dev, + "Read fan config for channel %d failed.\n", + channel); + return fan_config; + } + + fan_config |= (MAX31790_FAN_CFG_CTRL_MON | + MAX31790_FAN_CFG_TACH_INPUT); + i2c_smbus_write_byte_data( + client, MAX31790_REG_FAN_CONFIG(channel), + fan_config); + } + } + + return 0; +} + static int max31790_init_client(struct i2c_client *client, struct max31790_data *data) { @@ -521,6 +567,10 @@ static int max31790_probe(struct i2c_client *client) data->client = client; mutex_init(&data->update_lock); + err = max31790_config_pwm_as_tach(dev, client); + if (err) + dev_crit(dev, "Config PWM as TACH failed.\n"); + /* * Initialize the max31790 chip */
The PWM outputs of max31790 could be used as tachometer inputs by setting the fan configuration register, but the driver doesn't support to config the PWM outputs as tachometer inputs currently. Add a function to get properties of the setting of max31790 to config PWM outputs as tachometer inputs before initializing max31790. For example: set `pwm-as-tach = /bits/ 8 <2 5>` in DTS for max31790 and the driver will config PWMOUT2 and PWMOUT5 as TACH8 and TACH11. Signed-off-by: Delphine CC Chiu <Delphine_CC_Chiu@wiwynn.com> --- drivers/hwmon/max31790.c | 50 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+)