| Message ID | 1424254056-5904-8-git-send-email-l.majewski@samsung.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Eduardo Valentin |
| Headers | show |
On 02/18/2015 02:07 AM, Lukasz Majewski wrote: > This patch provides code for reading PWM FAN configuration data via > device tree. The pwm-fan can work with full speed when configuration > is not provided. However, errors are propagated when wrong DT bindings > are found. > Additionally the struct pwm_fan_ctx has been extended. > > Signed-off-by: Lukasz Majewski <l.majewski@samsung.com> > --- > Changes for v2: > - Rename pwm_fan_max_states to pwm_fan_cooling_levels > - Moving pwm_fan_of_get_cooling_data() call after setting end enabling PWM FAN > - pwm_fan_of_get_cooling_data() now can fail - preserving old behaviour > - Remove unnecessary dev_err() call > Changes for v3: > - Patch's headline has been reedited > - pwm_fan_of_get_cooling_data() return code is now being checked. > - of_property_count_elems_of_size() is now used instead of_find_property() > - More verbose patch description added > Changes for v4: > - dev_err() has been removed from pwm_fan_of_get_cooling_data() > - Returning -EINVAL when "cooling-levels" are defined in DT, but doesn't > have the value > --- > drivers/hwmon/pwm-fan.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 51 insertions(+), 1 deletion(-) > > diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c > index bd42d39..82cd06a 100644 > --- a/drivers/hwmon/pwm-fan.c > +++ b/drivers/hwmon/pwm-fan.c > @@ -30,7 +30,10 @@ > struct pwm_fan_ctx { > struct mutex lock; > struct pwm_device *pwm; > - unsigned char pwm_value; > + unsigned int pwm_value; > + unsigned int pwm_fan_state; > + unsigned int pwm_fan_max_state; > + unsigned int *pwm_fan_cooling_levels; > }; > > static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) > @@ -100,6 +103,48 @@ static struct attribute *pwm_fan_attrs[] = { > > ATTRIBUTE_GROUPS(pwm_fan); > > +int pwm_fan_of_get_cooling_data(struct device *dev, struct pwm_fan_ctx *ctx) > +{ > + struct device_node *np = dev->of_node; > + int num, i, ret; > + > + ret = of_property_count_elems_of_size(np, "cooling-levels", > + sizeof(u32)); > + > + if (ret == -EINVAL) > + return 0; The function returns -EINVAL if there is no such property, but also if prop->length % elem_size != 0. The latter _would_ be an error. Overall I don't entirely understand why you do not call of_find_property first. If that returns NULL, you would know for sure that the property does not exist, and you would not have to second guess the returned error from of_property_count_elems_of_size. On a side note, there is of_property_count_u32_elems() to count properties of size u32. > + > + if (ret <= 0) { > + dev_err(dev, "Wrong data!\n"); > + return ret ? ret : -EINVAL; > + } If devicetree is not configured, of_property_count_elems_of_size returns -ENOSYS, which is returned, causing the driver to fail loading. > + > + num = ret; > + ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, num * sizeof(u32), > + GFP_KERNEL); > + if (!ctx->pwm_fan_cooling_levels) > + return -ENOMEM; > + > + ret = of_property_read_u32_array(np, "cooling-levels", > + ctx->pwm_fan_cooling_levels, num); > + if (ret) { > + dev_err(dev, "Property 'cooling-levels' cannot be read!\n"); > + return ret; > + } > + > + for (i = 0; i < num; i++) { > + if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) { > + dev_err(dev, "PWM fan state[%d]:%d > %d\n", i, > + ctx->pwm_fan_cooling_levels[i], MAX_PWM); > + return -EINVAL; > + } > + } > + > + ctx->pwm_fan_max_state = num - 1; > + > + return 0; > +} > + > static int pwm_fan_probe(struct platform_device *pdev) > { > struct device *hwmon; > @@ -145,6 +190,11 @@ static int pwm_fan_probe(struct platform_device *pdev) > pwm_disable(ctx->pwm); > return PTR_ERR(hwmon); > } > + > + ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx); > + if (ret) > + return ret; > + > return 0; > } > > -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Guenter, > On 02/18/2015 02:07 AM, Lukasz Majewski wrote: > > This patch provides code for reading PWM FAN configuration data via > > device tree. The pwm-fan can work with full speed when configuration > > is not provided. However, errors are propagated when wrong DT > > bindings are found. > > Additionally the struct pwm_fan_ctx has been extended. > > > > Signed-off-by: Lukasz Majewski <l.majewski@samsung.com> > > --- > > Changes for v2: > > - Rename pwm_fan_max_states to pwm_fan_cooling_levels > > - Moving pwm_fan_of_get_cooling_data() call after setting end > > enabling PWM FAN > > - pwm_fan_of_get_cooling_data() now can fail - preserving old > > behaviour > > - Remove unnecessary dev_err() call > > Changes for v3: > > - Patch's headline has been reedited > > - pwm_fan_of_get_cooling_data() return code is now being checked. > > - of_property_count_elems_of_size() is now used instead > > of_find_property() > > - More verbose patch description added > > Changes for v4: > > - dev_err() has been removed from pwm_fan_of_get_cooling_data() > > - Returning -EINVAL when "cooling-levels" are defined in DT, but > > doesn't have the value > > --- > > drivers/hwmon/pwm-fan.c | 52 > > ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, > > 51 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c > > index bd42d39..82cd06a 100644 > > --- a/drivers/hwmon/pwm-fan.c > > +++ b/drivers/hwmon/pwm-fan.c > > @@ -30,7 +30,10 @@ > > struct pwm_fan_ctx { > > struct mutex lock; > > struct pwm_device *pwm; > > - unsigned char pwm_value; > > + unsigned int pwm_value; > > + unsigned int pwm_fan_state; > > + unsigned int pwm_fan_max_state; > > + unsigned int *pwm_fan_cooling_levels; > > }; > > > > static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) > > @@ -100,6 +103,48 @@ static struct attribute *pwm_fan_attrs[] = { > > > > ATTRIBUTE_GROUPS(pwm_fan); > > > > +int pwm_fan_of_get_cooling_data(struct device *dev, struct > > pwm_fan_ctx *ctx) +{ > > + struct device_node *np = dev->of_node; > > + int num, i, ret; > > + > > + ret = of_property_count_elems_of_size(np, "cooling-levels", > > + sizeof(u32)); > > + > > + if (ret == -EINVAL) > > + return 0; > > The function returns -EINVAL if there is no such property, > but also if prop->length % elem_size != 0. The latter _would_ > be an error. > > Overall I don't entirely understand why you do not call > of_find_property first. If that returns NULL, you would know for sure > that the property does not exist, and you would not have to second > guess the returned error from of_property_count_elems_of_size. For sake of readability I will at v5 first check of_find_property() and if it is correct, then I will call of_property_count_u32_elems(). > > On a side note, there is of_property_count_u32_elems() to count > properties of size u32. > > > + > > + if (ret <= 0) { > > + dev_err(dev, "Wrong data!\n"); > > + return ret ? ret : -EINVAL; > > + } > > If devicetree is not configured, of_property_count_elems_of_size > returns -ENOSYS, which is returned, causing the driver to fail > loading. Has of_property_count_elems_of_size() returns -ENOSYS? Maybe something has changed, but in my linux-vanila (3.19-rc4) at ./drivers/of/base.c it returns -EINVAL, -ENODATA or number of elements. Have I missed something? > > > + > > + num = ret; > > + ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, num * > > sizeof(u32), > > + GFP_KERNEL); > > + if (!ctx->pwm_fan_cooling_levels) > > + return -ENOMEM; > > + > > + ret = of_property_read_u32_array(np, "cooling-levels", > > + > > ctx->pwm_fan_cooling_levels, num); > > + if (ret) { > > + dev_err(dev, "Property 'cooling-levels' cannot be > > read!\n"); > > + return ret; > > + } > > + > > + for (i = 0; i < num; i++) { > > + if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) { > > + dev_err(dev, "PWM fan state[%d]:%d > > > %d\n", i, > > + ctx->pwm_fan_cooling_levels[i], > > MAX_PWM); > > + return -EINVAL; > > + } > > + } > > + > > + ctx->pwm_fan_max_state = num - 1; > > + > > + return 0; > > +} > > + > > static int pwm_fan_probe(struct platform_device *pdev) > > { > > struct device *hwmon; > > @@ -145,6 +190,11 @@ static int pwm_fan_probe(struct > > platform_device *pdev) pwm_disable(ctx->pwm); > > return PTR_ERR(hwmon); > > } > > + > > + ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx); > > + if (ret) > > + return ret; I think that here is the confusing part. Please compare this patch with the following one. Here we configure ctx struct via DT. If of_property_count_u32_elems() returns -EINVAL, then we consider that "cooling-levels" wasn't defined in DT and return with 0. Other error codes are considered as errors and probe return error code. > > + > > return 0; > > } > > > > >
On Mon, Feb 23, 2015 at 05:13:36PM +0100, Lukasz Majewski wrote: > Hi Guenter, > [ ... ] > > > > If devicetree is not configured, of_property_count_elems_of_size > > returns -ENOSYS, which is returned, causing the driver to fail > > loading. > > Has of_property_count_elems_of_size() returns -ENOSYS? > > Maybe something has changed, but in my linux-vanila (3.19-rc4) > at ./drivers/of/base.c it returns -EINVAL, -ENODATA or number of > elements. > > Have I missed something? > Hi Lukasz, Yes, you have. Check include/linux/of.h, line 484, in latest mainline. Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Guenter, > On Mon, Feb 23, 2015 at 05:13:36PM +0100, Lukasz Majewski wrote: > > Hi Guenter, > > > [ ... ] > > > > > > > If devicetree is not configured, of_property_count_elems_of_size > > > returns -ENOSYS, which is returned, causing the driver to fail > > > loading. > > > > Has of_property_count_elems_of_size() returns -ENOSYS? > > > > Maybe something has changed, but in my linux-vanila (3.19-rc4) > > at ./drivers/of/base.c it returns -EINVAL, -ENODATA or number of > > elements. > > > > Have I missed something? > > > Hi Lukasz, > > Yes, you have. Check include/linux/of.h, line 484, in latest mainline. Ok. Now I got it. The above situation shouldn't happen if I put of_find_property() check on the very beginning of this function (it returns NULL when DT support is not compiled). The function would look as follows: int pwm_fan_of_get_cooling_data(struct device *dev, struct pwm_fan_ctx *ctx) { struct device_node *np = dev->of_node; int num, i, ret; if (!of_find_property(np, "cooling-levels", NULL)) return 0; ret = of_property_count_u32_elems(np, "cooling-levels"); if (ret <= 0) { dev_err(dev, "Wrong data!\n"); return ret; } num = ret; ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, num * sizeof(u32), GFP_KERNEL); if (!ctx->pwm_fan_cooling_levels) return -ENOMEM; ret = of_property_read_u32_array(np, "cooling-levels", ctx->pwm_fan_cooling_levels, num); if (ret) { dev_err(dev, "Property 'cooling-levels' cannot be read!\n"); return ret; } for (i = 0; i < num; i++) { if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) { dev_err(dev, "PWM fan state[%d]:%d > %d\n", i, ctx->pwm_fan_cooling_levels[i], MAX_PWM); return -EINVAL; } } ctx->pwm_fan_max_state = num - 1; return 0; } > > Guenter
On Mon, Feb 23, 2015 at 05:51:22PM +0100, Lukasz Majewski wrote: > Hi Guenter, > > > On Mon, Feb 23, 2015 at 05:13:36PM +0100, Lukasz Majewski wrote: > > > Hi Guenter, > > > > > [ ... ] > > > > > > > > > > If devicetree is not configured, of_property_count_elems_of_size > > > > returns -ENOSYS, which is returned, causing the driver to fail > > > > loading. > > > > > > Has of_property_count_elems_of_size() returns -ENOSYS? > > > > > > Maybe something has changed, but in my linux-vanila (3.19-rc4) > > > at ./drivers/of/base.c it returns -EINVAL, -ENODATA or number of > > > elements. > > > > > > Have I missed something? > > > > > Hi Lukasz, > > > > Yes, you have. Check include/linux/of.h, line 484, in latest mainline. > > Ok. Now I got it. > > The above situation shouldn't happen if I put of_find_property() check > on the very beginning of this function (it returns NULL when DT support > is not compiled). > Correct. > The function would look as follows: > > int > pwm_fan_of_get_cooling_data(struct device *dev, struct pwm_fan_ctx > *ctx) > { > struct device_node *np = dev->of_node; > int num, i, ret; > > if (!of_find_property(np, "cooling-levels", NULL)) > return 0; > > ret = of_property_count_u32_elems(np, "cooling-levels"); > if (ret <= 0) { > dev_err(dev, "Wrong data!\n"); > return ret; This should probably be something like return ret ? : -EINVAL; or ret == 0 is not an error, and you should not display an error message in that case. Thanks, Guenter -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index bd42d39..82cd06a 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -30,7 +30,10 @@ struct pwm_fan_ctx { struct mutex lock; struct pwm_device *pwm; - unsigned char pwm_value; + unsigned int pwm_value; + unsigned int pwm_fan_state; + unsigned int pwm_fan_max_state; + unsigned int *pwm_fan_cooling_levels; }; static int __set_pwm(struct pwm_fan_ctx *ctx, unsigned long pwm) @@ -100,6 +103,48 @@ static struct attribute *pwm_fan_attrs[] = { ATTRIBUTE_GROUPS(pwm_fan); +int pwm_fan_of_get_cooling_data(struct device *dev, struct pwm_fan_ctx *ctx) +{ + struct device_node *np = dev->of_node; + int num, i, ret; + + ret = of_property_count_elems_of_size(np, "cooling-levels", + sizeof(u32)); + + if (ret == -EINVAL) + return 0; + + if (ret <= 0) { + dev_err(dev, "Wrong data!\n"); + return ret ? ret : -EINVAL; + } + + num = ret; + ctx->pwm_fan_cooling_levels = devm_kzalloc(dev, num * sizeof(u32), + GFP_KERNEL); + if (!ctx->pwm_fan_cooling_levels) + return -ENOMEM; + + ret = of_property_read_u32_array(np, "cooling-levels", + ctx->pwm_fan_cooling_levels, num); + if (ret) { + dev_err(dev, "Property 'cooling-levels' cannot be read!\n"); + return ret; + } + + for (i = 0; i < num; i++) { + if (ctx->pwm_fan_cooling_levels[i] > MAX_PWM) { + dev_err(dev, "PWM fan state[%d]:%d > %d\n", i, + ctx->pwm_fan_cooling_levels[i], MAX_PWM); + return -EINVAL; + } + } + + ctx->pwm_fan_max_state = num - 1; + + return 0; +} + static int pwm_fan_probe(struct platform_device *pdev) { struct device *hwmon; @@ -145,6 +190,11 @@ static int pwm_fan_probe(struct platform_device *pdev) pwm_disable(ctx->pwm); return PTR_ERR(hwmon); } + + ret = pwm_fan_of_get_cooling_data(&pdev->dev, ctx); + if (ret) + return ret; + return 0; }
This patch provides code for reading PWM FAN configuration data via device tree. The pwm-fan can work with full speed when configuration is not provided. However, errors are propagated when wrong DT bindings are found. Additionally the struct pwm_fan_ctx has been extended. Signed-off-by: Lukasz Majewski <l.majewski@samsung.com> --- Changes for v2: - Rename pwm_fan_max_states to pwm_fan_cooling_levels - Moving pwm_fan_of_get_cooling_data() call after setting end enabling PWM FAN - pwm_fan_of_get_cooling_data() now can fail - preserving old behaviour - Remove unnecessary dev_err() call Changes for v3: - Patch's headline has been reedited - pwm_fan_of_get_cooling_data() return code is now being checked. - of_property_count_elems_of_size() is now used instead of_find_property() - More verbose patch description added Changes for v4: - dev_err() has been removed from pwm_fan_of_get_cooling_data() - Returning -EINVAL when "cooling-levels" are defined in DT, but doesn't have the value --- drivers/hwmon/pwm-fan.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 51 insertions(+), 1 deletion(-)