[PATCH 0/3] hwmon: (lm85) add LM96000 high freqency pwm support

[PATCH 0/3] hwmon: (lm85) add LM96000 high freqency pwm support

[Jeremy Gebben]

Hi,

This patch adds support for the PWM frequencies from 22.5 to 30 kHz
available on the LM96000.

It looks like this chip has been supported for a long time, but wasn't
mentioned in the docs (which I have updated).

Also, it has been using the generic 'lm85' prefix, which I have not
changed to avoid breaking userspace or device tree files. AFAICT,
lm85_detect() will only return 'lm85' for LM96000 chips, so it doesn't
look like you can get a bare 'lm85' prefix with any other chips.

I stumbled on to a 10 year old thread discussing a patch which looks
like an early attempt to add support for this chip, which may be of
interest:
https://lm-sensors.lm-sensors.narkive.com/1SIwaMDT/patch-hwmon-lm96000-support

Thanks for reviewing,

Jeremy


Jeremy Gebben (3):
  hwmon: (lm85) remove freq_map size hardcodes
  hwmon: (lm85) Document the LM96000 as supported
  hwmon: (lm85) add support for LM96000 high frequencies

 Documentation/hwmon/lm85 |  9 ++++++++-
 drivers/hwmon/lm85.c     | 32 ++++++++++++++++++++++----------
 2 files changed, 30 insertions(+), 11 deletions(-)

-- 
2.17.1

Re: [PATCH 0/3] hwmon: (lm85) add LM96000 high freqency pwm support

[Guenter Roeck]

On Tue, Jan 29, 2019 at 02:29:17PM -0700, Jeremy Gebben wrote:
> Hi,
> 
> This patch adds support for the PWM frequencies from 22.5 to 30 kHz
> available on the LM96000.
> 
> It looks like this chip has been supported for a long time, but wasn't
> mentioned in the docs (which I have updated).
> 
> Also, it has been using the generic 'lm85' prefix, which I have not
> changed to avoid breaking userspace or device tree files. AFAICT,
> lm85_detect() will only return 'lm85' for LM96000 chips, so it doesn't
> look like you can get a bare 'lm85' prefix with any other chips.
> 
> I stumbled on to a 10 year old thread discussing a patch which looks
> like an early attempt to add support for this chip, which may be of
> interest:
> https://lm-sensors.lm-sensors.narkive.com/1SIwaMDT/patch-hwmon-lm96000-support
> 
> Thanks for reviewing,
> 
Where are the actual patches ?

Guenter

[PATCH resend 1/3] hwmon: (lm85) remove freq_map size hardcodes

[Jeremy Gebben]

Allow support for chips that support more than 8 frequencies.
The size still must be a power of two.

Signed-off-by: Jeremy Gebben <jgebben@sweptlaser.com>
---
 drivers/hwmon/lm85.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/drivers/hwmon/lm85.c b/drivers/hwmon/lm85.c
index 0a325878e8f5..48f59667a88c 100644
--- a/drivers/hwmon/lm85.c
+++ b/drivers/hwmon/lm85.c
@@ -198,13 +198,13 @@ static int RANGE_TO_REG(long range)
 #define RANGE_FROM_REG(val)	lm85_range_map[(val) & 0x0f]
 
 /* These are the PWM frequency encodings */
-static const int lm85_freq_map[8] = { /* 1 Hz */
+static const int lm85_freq_map[] = { /* 1 Hz */
 	10, 15, 23, 30, 38, 47, 61, 94
 };
-static const int adm1027_freq_map[8] = { /* 1 Hz */
+
+static const int adm1027_freq_map[] = { /* 1 Hz */
 	11, 15, 22, 29, 35, 44, 59, 88
 };
-#define FREQ_MAP_LEN	8
 
 static int FREQ_TO_REG(const int *map,
 		       unsigned int map_size, unsigned long freq)
@@ -212,9 +212,9 @@ static int FREQ_TO_REG(const int *map,
 	return find_closest(freq, map, map_size);
 }
 
-static int FREQ_FROM_REG(const int *map, u8 reg)
+static int FREQ_FROM_REG(const int *map, unsigned int map_size, u8 reg)
 {
-	return map[reg & 0x07];
+	return map[reg & (map_size - 1)];
 }
 
 /*
@@ -296,6 +296,8 @@ struct lm85_data {
 	struct i2c_client *client;
 	const struct attribute_group *groups[6];
 	const int *freq_map;
+	unsigned int freq_map_mask;
+
 	enum chips type;
 
 	bool has_vid5;	/* true if VID5 is configured for ADT7463 or ADT7468 */
@@ -514,7 +516,7 @@ static struct lm85_data *lm85_update_device(struct device *dev)
 			data->autofan[i].config =
 			    lm85_read_value(client, LM85_REG_AFAN_CONFIG(i));
 			val = lm85_read_value(client, LM85_REG_AFAN_RANGE(i));
-			data->pwm_freq[i] = val & 0x07;
+			data->pwm_freq[i] = val & data->freq_map_mask;
 			data->zone[i].range = val >> 4;
 			data->autofan[i].min_pwm =
 			    lm85_read_value(client, LM85_REG_AFAN_MINPWM(i));
@@ -791,7 +793,8 @@ static ssize_t show_pwm_freq(struct device *dev,
 	if (IS_ADT7468_HFPWM(data))
 		freq = 22500;
 	else
-		freq = FREQ_FROM_REG(data->freq_map, data->pwm_freq[nr]);
+		freq = FREQ_FROM_REG(data->freq_map, data->freq_map_mask + 1,
+				     data->pwm_freq[nr]);
 
 	return sprintf(buf, "%d\n", freq);
 }
@@ -820,7 +823,7 @@ static ssize_t set_pwm_freq(struct device *dev,
 		lm85_write_value(client, ADT7468_REG_CFG5, data->cfg5);
 	} else {					/* Low freq. mode */
 		data->pwm_freq[nr] = FREQ_TO_REG(data->freq_map,
-						 FREQ_MAP_LEN, val);
+						 data->freq_map_mask + 1, val);
 		lm85_write_value(client, LM85_REG_AFAN_RANGE(nr),
 				 (data->zone[nr].range << 4)
 				 | data->pwm_freq[nr]);
@@ -1196,7 +1199,7 @@ static ssize_t set_temp_auto_temp_min(struct device *dev,
 		TEMP_FROM_REG(data->zone[nr].limit));
 	lm85_write_value(client, LM85_REG_AFAN_RANGE(nr),
 		((data->zone[nr].range & 0x0f) << 4)
-		| (data->pwm_freq[nr] & 0x07));
+		| data->pwm_freq[nr]);
 
 	mutex_unlock(&data->update_lock);
 	return count;
@@ -1232,7 +1235,7 @@ static ssize_t set_temp_auto_temp_max(struct device *dev,
 		val - min);
 	lm85_write_value(client, LM85_REG_AFAN_RANGE(nr),
 		((data->zone[nr].range & 0x0f) << 4)
-		| (data->pwm_freq[nr] & 0x07));
+		| data->pwm_freq[nr]);
 	mutex_unlock(&data->update_lock);
 	return count;
 }
@@ -1569,9 +1572,11 @@ static int lm85_probe(struct i2c_client *client, const struct i2c_device_id *id)
 	case emc6d103:
 	case emc6d103s:
 		data->freq_map = adm1027_freq_map;
+		data->freq_map_mask = ARRAY_SIZE(adm1027_freq_map) - 1;
 		break;
 	default:
 		data->freq_map = lm85_freq_map;
+		data->freq_map_mask = ARRAY_SIZE(lm85_freq_map) - 1;
 	}
 
 	/* Set the VRM version */
-- 
2.17.1

[PATCH resend 2/3] hwmon: (lm85) Document the LM96000 as supported

[Jeremy Gebben]

It has been supported as a generic lm85 for quite some time.

Signed-off-by: Jeremy Gebben <jgebben@sweptlaser.com>
---
 Documentation/hwmon/lm85 | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/Documentation/hwmon/lm85 b/Documentation/hwmon/lm85
index 7c49feaa79d2..9f3a945d1b80 100644
--- a/Documentation/hwmon/lm85
+++ b/Documentation/hwmon/lm85
@@ -3,9 +3,13 @@ Kernel driver lm85
 
 Supported chips:
   * National Semiconductor LM85 (B and C versions)
-    Prefix: 'lm85'
+    Prefix: 'lm85b' or 'lm85c'
     Addresses scanned: I2C 0x2c, 0x2d, 0x2e
     Datasheet: http://www.national.com/pf/LM/LM85.html
+  * Texas Instruments LM96000
+    Prefix: 'lm85'
+    Addresses scanned: I2C 0x2c, 0x2d, 0x2e
+    Datasheet: http://www.ti.com/lit/ds/symlink/lm96000.pdf
   * Analog Devices ADM1027
     Prefix: 'adm1027'
     Addresses scanned: I2C 0x2c, 0x2d, 0x2e
-- 
2.17.1

[PATCH resend 3/3] hwmon: (lm85) add support for LM96000 high frequencies

[Jeremy Gebben]

This chip expands the freqency field from 3 to 4 bits, to
add more frequencies in the 22.5 to 30 kHz ranges.

Signed-off-by: Jeremy Gebben <jgebben@sweptlaser.com>
---
 Documentation/hwmon/lm85 | 3 +++
 drivers/hwmon/lm85.c     | 9 +++++++++
 2 files changed, 12 insertions(+)

diff --git a/Documentation/hwmon/lm85 b/Documentation/hwmon/lm85
index 9f3a945d1b80..264874f09196 100644
--- a/Documentation/hwmon/lm85
+++ b/Documentation/hwmon/lm85
@@ -140,6 +140,9 @@ of voltage and temperature channels.
 SMSC EMC6D103S is similar to EMC6D103, but does not support pwm#_auto_pwm_minctl
 and temp#_auto_temp_off.
 
+The LM96000 supports additional high frequency PWM modes (22.5 kHz, 24 kHz,
+25.7 kHz, 27.7 kHz and 30 kHz), which can be configured on a per-PWM basis.
+
 Hardware Configurations
 -----------------------
 
diff --git a/drivers/hwmon/lm85.c b/drivers/hwmon/lm85.c
index 48f59667a88c..37bfa7d105a2 100644
--- a/drivers/hwmon/lm85.c
+++ b/drivers/hwmon/lm85.c
@@ -202,6 +202,11 @@ static const int lm85_freq_map[] = { /* 1 Hz */
 	10, 15, 23, 30, 38, 47, 61, 94
 };
 
+static const int lm85_high_freq_map[] = { /* 1 Hz */
+	10, 15, 23, 30, 38, 47, 61, 94,
+	22500, 24000, 25700, 25700, 27700, 27700, 30000, 30000
+};
+
 static const int adm1027_freq_map[] = { /* 1 Hz */
 	11, 15, 22, 29, 35, 44, 59, 88
 };
@@ -1574,6 +1579,10 @@ static int lm85_probe(struct i2c_client *client, const struct i2c_device_id *id)
 		data->freq_map = adm1027_freq_map;
 		data->freq_map_mask = ARRAY_SIZE(adm1027_freq_map) - 1;
 		break;
+	case lm85:
+		data->freq_map = lm85_high_freq_map;
+		data->freq_map_mask = ARRAY_SIZE(lm85_high_freq_map) - 1;
+		break;
 	default:
 		data->freq_map = lm85_freq_map;
 		data->freq_map_mask = ARRAY_SIZE(lm85_freq_map) - 1;
-- 
2.17.1

Re: [PATCH 0/3] hwmon: (lm85) add LM96000 high freqency pwm support

[Jeremy Gebben]

On Tue, Jan 29, 2019 at 4:38 PM Guenter Roeck <linux@roeck-us.net> wrote:
>
> On Tue, Jan 29, 2019 at 02:29:17PM -0700, Jeremy Gebben wrote:
> > Hi,
> >
> > This patch adds support for the PWM frequencies from 22.5 to 30 kHz
> > available on the LM96000.
> >
> > It looks like this chip has been supported for a long time, but wasn't
> > mentioned in the docs (which I have updated).
> >
> > Also, it has been using the generic 'lm85' prefix, which I have not
> > changed to avoid breaking userspace or device tree files. AFAICT,
> > lm85_detect() will only return 'lm85' for LM96000 chips, so it doesn't
> > look like you can get a bare 'lm85' prefix with any other chips.
> >
> > I stumbled on to a 10 year old thread discussing a patch which looks
> > like an early attempt to add support for this chip, which may be of
> > interest:
> > https://lm-sensors.lm-sensors.narkive.com/1SIwaMDT/patch-hwmon-lm96000-support
> >
> > Thanks for reviewing,
> >
> Where are the actual patches ?

Oops! It looks like they didn't send correctly. Hopefully they should
be showing up shortly.

Jeremy

>
> Guenter

Re: [PATCH resend 1/3] hwmon: (lm85) remove freq_map size hardcodes

[Guenter Roeck]

On Wed, Jan 30, 2019 at 09:14:45AM -0700, Jeremy Gebben wrote:
> 
> Allow support for chips that support more than 8 frequencies.
> The size still must be a power of two.
> 
This is risky. Someone later may not know/remember and 
expand the table without maintaining that restriction.
I would suggest to use map_size instead of map_mask.
While that adds some divide operations, none of those are
in a critical path, and the code would be much more robust.

> Signed-off-by: Jeremy Gebben <jgebben@sweptlaser.com>
> ---
>  drivers/hwmon/lm85.c | 25 +++++++++++++++----------
>  1 file changed, 15 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/hwmon/lm85.c b/drivers/hwmon/lm85.c
> index 0a325878e8f5..48f59667a88c 100644
> --- a/drivers/hwmon/lm85.c
> +++ b/drivers/hwmon/lm85.c
> @@ -198,13 +198,13 @@ static int RANGE_TO_REG(long range)
>  #define RANGE_FROM_REG(val)	lm85_range_map[(val) & 0x0f]
>  
>  /* These are the PWM frequency encodings */
> -static const int lm85_freq_map[8] = { /* 1 Hz */
> +static const int lm85_freq_map[] = { /* 1 Hz */
>  	10, 15, 23, 30, 38, 47, 61, 94
>  };
> -static const int adm1027_freq_map[8] = { /* 1 Hz */
> +
> +static const int adm1027_freq_map[] = { /* 1 Hz */
>  	11, 15, 22, 29, 35, 44, 59, 88
>  };
> -#define FREQ_MAP_LEN	8
>  
>  static int FREQ_TO_REG(const int *map,
>  		       unsigned int map_size, unsigned long freq)
> @@ -212,9 +212,9 @@ static int FREQ_TO_REG(const int *map,
>  	return find_closest(freq, map, map_size);
>  }
>  
> -static int FREQ_FROM_REG(const int *map, u8 reg)
> +static int FREQ_FROM_REG(const int *map, unsigned int map_size, u8 reg)
>  {
> -	return map[reg & 0x07];
> +	return map[reg & (map_size - 1)];

Passing in map_size (calculated as map_mask + 1) just to subtract one
doesn't make sense.

>  }
>  
>  /*
> @@ -296,6 +296,8 @@ struct lm85_data {
>  	struct i2c_client *client;
>  	const struct attribute_group *groups[6];
>  	const int *freq_map;
> +	unsigned int freq_map_mask;
> +
>  	enum chips type;
>  
>  	bool has_vid5;	/* true if VID5 is configured for ADT7463 or ADT7468 */
> @@ -514,7 +516,7 @@ static struct lm85_data *lm85_update_device(struct device *dev)
>  			data->autofan[i].config =
>  			    lm85_read_value(client, LM85_REG_AFAN_CONFIG(i));
>  			val = lm85_read_value(client, LM85_REG_AFAN_RANGE(i));
> -			data->pwm_freq[i] = val & 0x07;
> +			data->pwm_freq[i] = val & data->freq_map_mask;
>  			data->zone[i].range = val >> 4;
>  			data->autofan[i].min_pwm =
>  			    lm85_read_value(client, LM85_REG_AFAN_MINPWM(i));
> @@ -791,7 +793,8 @@ static ssize_t show_pwm_freq(struct device *dev,
>  	if (IS_ADT7468_HFPWM(data))
>  		freq = 22500;
>  	else
> -		freq = FREQ_FROM_REG(data->freq_map, data->pwm_freq[nr]);
> +		freq = FREQ_FROM_REG(data->freq_map, data->freq_map_mask + 1,
> +				     data->pwm_freq[nr]);
>  
>  	return sprintf(buf, "%d\n", freq);
>  }
> @@ -820,7 +823,7 @@ static ssize_t set_pwm_freq(struct device *dev,
>  		lm85_write_value(client, ADT7468_REG_CFG5, data->cfg5);
>  	} else {					/* Low freq. mode */
>  		data->pwm_freq[nr] = FREQ_TO_REG(data->freq_map,
> -						 FREQ_MAP_LEN, val);
> +						 data->freq_map_mask + 1, val);
>  		lm85_write_value(client, LM85_REG_AFAN_RANGE(nr),
>  				 (data->zone[nr].range << 4)
>  				 | data->pwm_freq[nr]);
> @@ -1196,7 +1199,7 @@ static ssize_t set_temp_auto_temp_min(struct device *dev,
>  		TEMP_FROM_REG(data->zone[nr].limit));
>  	lm85_write_value(client, LM85_REG_AFAN_RANGE(nr),
>  		((data->zone[nr].range & 0x0f) << 4)
> -		| (data->pwm_freq[nr] & 0x07));
> +		| data->pwm_freq[nr]);
>  
>  	mutex_unlock(&data->update_lock);
>  	return count;
> @@ -1232,7 +1235,7 @@ static ssize_t set_temp_auto_temp_max(struct device *dev,
>  		val - min);
>  	lm85_write_value(client, LM85_REG_AFAN_RANGE(nr),
>  		((data->zone[nr].range & 0x0f) << 4)
> -		| (data->pwm_freq[nr] & 0x07));
> +		| data->pwm_freq[nr]);
>  	mutex_unlock(&data->update_lock);
>  	return count;
>  }
> @@ -1569,9 +1572,11 @@ static int lm85_probe(struct i2c_client *client, const struct i2c_device_id *id)
>  	case emc6d103:
>  	case emc6d103s:
>  		data->freq_map = adm1027_freq_map;
> +		data->freq_map_mask = ARRAY_SIZE(adm1027_freq_map) - 1;
>  		break;
>  	default:
>  		data->freq_map = lm85_freq_map;
> +		data->freq_map_mask = ARRAY_SIZE(lm85_freq_map) - 1;
>  	}

You'd have to make sure that freq_map_mask is indeed a mask, ie that
ARRAY_SIZE() is a power of two. I would suggest to use freq_map_size
instead.

>  
>  	/* Set the VRM version */
> -- 
> 2.17.1
>