| Message ID | 20241105135259.101126-2-marex@denx.de (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [1/2] dt-bindings: hwmon: pwm-fan: Document start from dead stop properties | expand |
On 11/5/24 05:52, Marek Vasut wrote: > Delta AFC0612DB-F00 fan has to be set to at least 30% PWM duty cycle > to spin up from a dead stop, and can be afterward throttled down to > lower PWM duty cycle. Introduce support for operating such fans which > need to start at higher PWM duty cycle first and can slow down next. > > Introduce two new DT properties, "fan-dead-stop-start-percent" and > "fan-dead-stop-start-usec". The former describes the minimum percent > of fan RPM at which it will surely spin up from dead stop. This value > can be found in the fan datasheet and can be converted to PWM duty > cycle easily. The "fan-dead-stop-start-usec" describes the minimum > time in microseconds for which the fan has to be set to dead stop > start RPM for the fan to surely spin up. > > Adjust the PWM setting code such that if the PWM duty cycle is below > the minimum duty cycle needed by the fan to spin up from dead stop, > then first set the PWM duty cycle to the minimum duty cycle needed > by the fan to spin up from dead stop, then wait the time necessary > for the fan to spin up from dead stop, and finally set the PWM duty > cycle to the one desired by user. > As with the other patch, I don't think "dead" adds any value anywhere. Guenter > Signed-off-by: Marek Vasut <marex@denx.de> > --- > Cc: Conor Dooley <conor+dt@kernel.org> > Cc: Guenter Roeck <linux@roeck-us.net> > Cc: Jean Delvare <jdelvare@suse.com> > Cc: Krzysztof Kozlowski <krzk+dt@kernel.org> > Cc: Rob Herring <robh@kernel.org> > Cc: devicetree@vger.kernel.org > Cc: linux-hwmon@vger.kernel.org > --- > drivers/hwmon/pwm-fan.c | 33 ++++++++++++++++++++++++++++++++- > 1 file changed, 32 insertions(+), 1 deletion(-) > > diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c > index c434db4656e7d..264b7ddf8bb40 100644 > --- a/drivers/hwmon/pwm-fan.c > +++ b/drivers/hwmon/pwm-fan.c > @@ -7,6 +7,7 @@ > * Author: Kamil Debski <k.debski@samsung.com> > */ > > +#include <linux/delay.h> > #include <linux/hwmon.h> > #include <linux/interrupt.h> > #include <linux/mod_devicetable.h> > @@ -60,6 +61,9 @@ struct pwm_fan_ctx { > > struct hwmon_chip_info info; > struct hwmon_channel_info fan_channel; > + > + u64 pwm_duty_cycle_from_dead_stop; > + u32 pwm_usec_from_dead_stop; > }; > > /* This handler assumes self resetting edge triggered interrupt. */ > @@ -199,7 +203,9 @@ static int pwm_fan_power_off(struct pwm_fan_ctx *ctx, bool force_disable) > static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) > { > struct pwm_state *state = &ctx->pwm_state; > + unsigned long final_pwm = pwm; > unsigned long period; > + bool update = false; > int ret = 0; > > if (pwm > 0) { > @@ -208,11 +214,22 @@ static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) > return 0; > > period = state->period; > - state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); > + update = state->duty_cycle < ctx->pwm_duty_cycle_from_dead_stop; > + if (update) > + state->duty_cycle = ctx->pwm_duty_cycle_from_dead_stop; > + else > + state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); > ret = pwm_apply_might_sleep(ctx->pwm, state); > if (ret) > return ret; > ret = pwm_fan_power_on(ctx); > + if (!ret && update) { > + pwm = final_pwm; > + state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); > + usleep_range(ctx->pwm_usec_from_dead_stop, > + ctx->pwm_usec_from_dead_stop * 2); > + ret = pwm_apply_might_sleep(ctx->pwm, state); > + } > } else { > ret = pwm_fan_power_off(ctx, false); > } > @@ -480,6 +497,7 @@ static int pwm_fan_probe(struct platform_device *pdev) > struct device *hwmon; > int ret; > const struct hwmon_channel_info **channels; > + u32 pwm_min_from_dead_stop = 0; > u32 *fan_channel_config; > int channel_count = 1; /* We always have a PWM channel. */ > int i; > @@ -620,6 +638,19 @@ static int pwm_fan_probe(struct platform_device *pdev) > channels[1] = &ctx->fan_channel; > } > > + ret = of_property_read_u32(dev->of_node, "fan-dead-stop-start-percent", > + &pwm_min_from_dead_stop); > + if (!ret && pwm_min_from_dead_stop) { > + ctx->pwm_duty_cycle_from_dead_stop = > + DIV_ROUND_UP(pwm_min_from_dead_stop * > + (ctx->pwm_state.period - 1), > + 100); > + } > + ret = of_property_read_u32(dev->of_node, "fan-dead-stop-start-usec", > + &ctx->pwm_usec_from_dead_stop); > + if (ret) > + ctx->pwm_usec_from_dead_stop = 250000; > + > ctx->info.ops = &pwm_fan_hwmon_ops; > ctx->info.info = channels; >
Hi Marek,
kernel test robot noticed the following build errors:
[auto build test ERROR on groeck-staging/hwmon-next]
[also build test ERROR on linus/master v6.12-rc6 next-20241105]
[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/Marek-Vasut/hwmon-pwm-fan-Introduce-start-from-dead-stop-handling/20241105-215454
base: https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
patch link: https://lore.kernel.org/r/20241105135259.101126-2-marex%40denx.de
patch subject: [PATCH 2/2] hwmon: (pwm-fan) Introduce start from dead stop handling
config: arm-defconfig (https://download.01.org/0day-ci/archive/20241106/202411061031.GHHHxm19-lkp@intel.com/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241106/202411061031.GHHHxm19-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/202411061031.GHHHxm19-lkp@intel.com/
All errors (new ones prefixed by >>, old ones prefixed by <<):
>> ERROR: modpost: "__aeabi_uldivmod" [drivers/hwmon/pwm-fan.ko] undefined!
Hi Marek,
kernel test robot noticed the following build errors:
[auto build test ERROR on groeck-staging/hwmon-next]
[also build test ERROR on linus/master v6.12-rc6 next-20241106]
[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/Marek-Vasut/hwmon-pwm-fan-Introduce-start-from-dead-stop-handling/20241105-215454
base: https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
patch link: https://lore.kernel.org/r/20241105135259.101126-2-marex%40denx.de
patch subject: [PATCH 2/2] hwmon: (pwm-fan) Introduce start from dead stop handling
config: i386-randconfig-016-20241106 (https://download.01.org/0day-ci/archive/20241107/202411070251.mEqY5ErJ-lkp@intel.com/config)
compiler: clang version 19.1.3 (https://github.com/llvm/llvm-project ab51eccf88f5321e7c60591c5546b254b6afab99)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20241107/202411070251.mEqY5ErJ-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/202411070251.mEqY5ErJ-lkp@intel.com/
All errors (new ones prefixed by >>, old ones prefixed by <<):
>> ERROR: modpost: "__udivdi3" [drivers/hwmon/pwm-fan.ko] undefined!
diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index c434db4656e7d..264b7ddf8bb40 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -7,6 +7,7 @@ * Author: Kamil Debski <k.debski@samsung.com> */ +#include <linux/delay.h> #include <linux/hwmon.h> #include <linux/interrupt.h> #include <linux/mod_devicetable.h> @@ -60,6 +61,9 @@ struct pwm_fan_ctx { struct hwmon_chip_info info; struct hwmon_channel_info fan_channel; + + u64 pwm_duty_cycle_from_dead_stop; + u32 pwm_usec_from_dead_stop; }; /* This handler assumes self resetting edge triggered interrupt. */ @@ -199,7 +203,9 @@ static int pwm_fan_power_off(struct pwm_fan_ctx *ctx, bool force_disable) static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) { struct pwm_state *state = &ctx->pwm_state; + unsigned long final_pwm = pwm; unsigned long period; + bool update = false; int ret = 0; if (pwm > 0) { @@ -208,11 +214,22 @@ static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) return 0; period = state->period; - state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); + update = state->duty_cycle < ctx->pwm_duty_cycle_from_dead_stop; + if (update) + state->duty_cycle = ctx->pwm_duty_cycle_from_dead_stop; + else + state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); ret = pwm_apply_might_sleep(ctx->pwm, state); if (ret) return ret; ret = pwm_fan_power_on(ctx); + if (!ret && update) { + pwm = final_pwm; + state->duty_cycle = DIV_ROUND_UP(pwm * (period - 1), MAX_PWM); + usleep_range(ctx->pwm_usec_from_dead_stop, + ctx->pwm_usec_from_dead_stop * 2); + ret = pwm_apply_might_sleep(ctx->pwm, state); + } } else { ret = pwm_fan_power_off(ctx, false); } @@ -480,6 +497,7 @@ static int pwm_fan_probe(struct platform_device *pdev) struct device *hwmon; int ret; const struct hwmon_channel_info **channels; + u32 pwm_min_from_dead_stop = 0; u32 *fan_channel_config; int channel_count = 1; /* We always have a PWM channel. */ int i; @@ -620,6 +638,19 @@ static int pwm_fan_probe(struct platform_device *pdev) channels[1] = &ctx->fan_channel; } + ret = of_property_read_u32(dev->of_node, "fan-dead-stop-start-percent", + &pwm_min_from_dead_stop); + if (!ret && pwm_min_from_dead_stop) { + ctx->pwm_duty_cycle_from_dead_stop = + DIV_ROUND_UP(pwm_min_from_dead_stop * + (ctx->pwm_state.period - 1), + 100); + } + ret = of_property_read_u32(dev->of_node, "fan-dead-stop-start-usec", + &ctx->pwm_usec_from_dead_stop); + if (ret) + ctx->pwm_usec_from_dead_stop = 250000; + ctx->info.ops = &pwm_fan_hwmon_ops; ctx->info.info = channels;
Delta AFC0612DB-F00 fan has to be set to at least 30% PWM duty cycle to spin up from a dead stop, and can be afterward throttled down to lower PWM duty cycle. Introduce support for operating such fans which need to start at higher PWM duty cycle first and can slow down next. Introduce two new DT properties, "fan-dead-stop-start-percent" and "fan-dead-stop-start-usec". The former describes the minimum percent of fan RPM at which it will surely spin up from dead stop. This value can be found in the fan datasheet and can be converted to PWM duty cycle easily. The "fan-dead-stop-start-usec" describes the minimum time in microseconds for which the fan has to be set to dead stop start RPM for the fan to surely spin up. Adjust the PWM setting code such that if the PWM duty cycle is below the minimum duty cycle needed by the fan to spin up from dead stop, then first set the PWM duty cycle to the minimum duty cycle needed by the fan to spin up from dead stop, then wait the time necessary for the fan to spin up from dead stop, and finally set the PWM duty cycle to the one desired by user. Signed-off-by: Marek Vasut <marex@denx.de> --- Cc: Conor Dooley <conor+dt@kernel.org> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Jean Delvare <jdelvare@suse.com> Cc: Krzysztof Kozlowski <krzk+dt@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: devicetree@vger.kernel.org Cc: linux-hwmon@vger.kernel.org --- drivers/hwmon/pwm-fan.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-)