[PATCH] Fix incomplete initialization of ADC[3:6]

[PATCH] Fix incomplete initialization of ADC[3:6]

[Adam YH Lee]

TPS65950(TWL4030) paired with OMAP3 is used in devices such as Beagleboard and
Gumstix Overo COMs. Its ADCs from 3 to 6 seem to be broken [1][2][3].

The ADC readings for these pins are stuck at near 0v for these two reasons:
        - 3v1 bias regulator (vusb3v1) is off unless USB-otg is being used
        - pins are not configured to attach as ADC

This patch attempts to fix these issues by making sure 3v1 regulator is enabled
and pins are correctly configured as ADC inputs.

[1] http://comments.gmane.org/gmane.linux.ports.arm.omap/83698
[2] http://gumstix.8.x6.nabble.com/twl4030-madc-low-read-value-td4967139.html#none
[3] https://e2e.ti.com/support/power_management/pmu/f/43/t/732

Adam YH Lee (1):
  [TWL4030 MADC] Fix ADC[3:6] readings

 drivers/iio/adc/twl4030-madc.c | 14 ++++++++++++++
 drivers/phy/phy-twl4030-usb.c  |  7 +++++++
 2 files changed, 21 insertions(+)

-- 
2.1.4

[PATCH] Fix incomplete initialization of ADC[3:6]$

[Adam YH Lee]

Additionally the original discussion for this patch can be found here [5].
$
[1] http://comments.gmane.org/gmane.linux.ports.arm.omap/83698$
[2] http://gumstix.8.x6.nabble.com/twl4030-madc-low-read-value-td4967139.html#none$
[3] https://e2e.ti.com/support/power_management/pmu/f/43/t/732$
[4] http://www.droid-developers.org/images/2/21/Tps65950_TRM.pdf$
[5] http://www.spinics.net/lists/linux-omap/msg120300.html

Adam YH Lee (1):
  [TWL4030 MADC] Fix ADC[3:6] readings

 drivers/iio/adc/twl4030-madc.c | 14 ++++++++++++++
 drivers/phy/phy-twl4030-usb.c  |  7 +++++++
 2 files changed, 21 insertions(+)

-- 
2.1.4

[PATCH] [TWL4030 MADC] Fix ADC[3:6] readings

[Adam YH Lee]

MADC[3:6] reads incorrect values without these two following changes:

- enable the 3v1 bias regulator for ADC[3:6]
- configure ADC[3:6] lines as input, not as USB

Signed-off-by: Adam YH Lee <adam.yh.lee@gmail.com>
---
 drivers/iio/adc/twl4030-madc.c | 14 ++++++++++++++
 drivers/phy/phy-twl4030-usb.c  |  7 +++++++
 2 files changed, 21 insertions(+)

diff --git a/drivers/iio/adc/twl4030-madc.c b/drivers/iio/adc/twl4030-madc.c
index 94c5f05..b5020ab 100644
--- a/drivers/iio/adc/twl4030-madc.c
+++ b/drivers/iio/adc/twl4030-madc.c
@@ -45,6 +45,7 @@
 #include <linux/types.h>
 #include <linux/gfp.h>
 #include <linux/err.h>
+#include <linux/regulator/consumer.h>
 
 #include <linux/iio/iio.h>
 
@@ -52,6 +53,7 @@
  * struct twl4030_madc_data - a container for madc info
  * @dev:		Pointer to device structure for madc
  * @lock:		Mutex protecting this data structure
+ * @regulator:		Pointer to bias regulator for madc
  * @requests:		Array of request struct corresponding to SW1, SW2 and RT
  * @use_second_irq:	IRQ selection (main or co-processor)
  * @imr:		Interrupt mask register of MADC
@@ -60,6 +62,7 @@
 struct twl4030_madc_data {
 	struct device *dev;
 	struct mutex lock;	/* mutex protecting this data structure */
+	struct regulator *usb3v1;
 	struct twl4030_madc_request requests[TWL4030_MADC_NUM_METHODS];
 	bool use_second_irq;
 	u8 imr;
@@ -848,6 +851,14 @@ static int twl4030_madc_probe(struct platform_device *pdev)
 		goto err_i2c;
 	}
 
+	madc->usb3v1 = devm_regulator_get(madc->dev, "vusb3v1");
+	if (IS_ERR(madc->usb3v1))
+		return -ENODEV;
+
+	ret = regulator_enable(madc->usb3v1);
+	if (ret)
+		dev_err(madc->dev, "could not be enable 3v1 bias regulator\n");
+
 	return 0;
 
 err_i2c:
@@ -867,6 +878,9 @@ static int twl4030_madc_remove(struct platform_device *pdev)
 	twl4030_madc_set_current_generator(madc, 0, 0);
 	twl4030_madc_set_power(madc, 0);
 
+	regulator_disable(madc->usb3v1);
+	regulator_put(madc->usb3v1);
+
 	return 0;
 }
 
diff --git a/drivers/phy/phy-twl4030-usb.c b/drivers/phy/phy-twl4030-usb.c
index 7b04bef..88fc7d7 100644
--- a/drivers/phy/phy-twl4030-usb.c
+++ b/drivers/phy/phy-twl4030-usb.c
@@ -144,6 +144,9 @@
 #define PMBR1				0x0D
 #define GPIO_USB_4PIN_ULPI_2430C	(3 << 0)
 
+#define TWL4030_USB_SEL_MADC_MCPC	(1<<3)
+#define TWL4030_USB_CARKIT_ANA_CTRL	0xBB
+
 struct twl4030_usb {
 	struct usb_phy		phy;
 	struct device		*dev;
@@ -459,6 +462,10 @@ static int twl4030_phy_power_on(struct phy *phy)
 		twl4030_i2c_access(twl, 0);
 	schedule_delayed_work(&twl->id_workaround_work, 0);
 
+	twl4030_usb_write(twl, TWL4030_USB_CARKIT_ANA_CTRL,
+		twl4030_usb_read(twl, TWL4030_USB_CARKIT_ANA_CTRL) |
+		TWL4030_USB_SEL_MADC_MCPC);
+
 	return 0;
 }
 
-- 
2.1.4

[PATCH] [TWL4030 MADC] Fix ADC[3:6] readings

[Peter Meerwald]

On Mon, 20 Jul 2015, Adam YH Lee wrote:

> MADC[3:6] reads incorrect values without these two following changes:
> 
> - enable the 3v1 bias regulator for ADC[3:6]
> - configure ADC[3:6] lines as input, not as USB

comments below
 
> Signed-off-by: Adam YH Lee <adam.yh.lee@gmail.com>
> ---
>  drivers/iio/adc/twl4030-madc.c | 14 ++++++++++++++
>  drivers/phy/phy-twl4030-usb.c  |  7 +++++++
>  2 files changed, 21 insertions(+)
> 
> diff --git a/drivers/iio/adc/twl4030-madc.c b/drivers/iio/adc/twl4030-madc.c
> index 94c5f05..b5020ab 100644
> --- a/drivers/iio/adc/twl4030-madc.c
> +++ b/drivers/iio/adc/twl4030-madc.c
> @@ -45,6 +45,7 @@
>  #include <linux/types.h>
>  #include <linux/gfp.h>
>  #include <linux/err.h>
> +#include <linux/regulator/consumer.h>
>  
>  #include <linux/iio/iio.h>
>  
> @@ -52,6 +53,7 @@
>   * struct twl4030_madc_data - a container for madc info
>   * @dev:		Pointer to device structure for madc
>   * @lock:		Mutex protecting this data structure
> + * @regulator:		Pointer to bias regulator for madc
>   * @requests:		Array of request struct corresponding to SW1, SW2 and RT
>   * @use_second_irq:	IRQ selection (main or co-processor)
>   * @imr:		Interrupt mask register of MADC
> @@ -60,6 +62,7 @@
>  struct twl4030_madc_data {
>  	struct device *dev;
>  	struct mutex lock;	/* mutex protecting this data structure */
> +	struct regulator *usb3v1;
>  	struct twl4030_madc_request requests[TWL4030_MADC_NUM_METHODS];
>  	bool use_second_irq;
>  	u8 imr;
> @@ -848,6 +851,14 @@ static int twl4030_madc_probe(struct platform_device *pdev)
>  		goto err_i2c;
>  	}
>  
> +	madc->usb3v1 = devm_regulator_get(madc->dev, "vusb3v1");
> +	if (IS_ERR(madc->usb3v1))
> +		return -ENODEV;
> +
> +	ret = regulator_enable(madc->usb3v1);
> +	if (ret)
> +		dev_err(madc->dev, "could not be enable 3v1 bias regulator\n");

please fix wording, "could not enable usb 3v1 bias regulator" probably

> +
>  	return 0;
>  
>  err_i2c:
> @@ -867,6 +878,9 @@ static int twl4030_madc_remove(struct platform_device *pdev)
>  	twl4030_madc_set_current_generator(madc, 0, 0);
>  	twl4030_madc_set_power(madc, 0);
>  
> +	regulator_disable(madc->usb3v1);
> +	regulator_put(madc->usb3v1);
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/phy/phy-twl4030-usb.c b/drivers/phy/phy-twl4030-usb.c
> index 7b04bef..88fc7d7 100644
> --- a/drivers/phy/phy-twl4030-usb.c
> +++ b/drivers/phy/phy-twl4030-usb.c
> @@ -144,6 +144,9 @@
>  #define PMBR1				0x0D
>  #define GPIO_USB_4PIN_ULPI_2430C	(3 << 0)
>  
> +#define TWL4030_USB_SEL_MADC_MCPC	(1<<3)
> +#define TWL4030_USB_CARKIT_ANA_CTRL	0xBB
> +
>  struct twl4030_usb {
>  	struct usb_phy		phy;
>  	struct device		*dev;
> @@ -459,6 +462,10 @@ static int twl4030_phy_power_on(struct phy *phy)
>  		twl4030_i2c_access(twl, 0);
>  	schedule_delayed_work(&twl->id_workaround_work, 0);
>  
> +	twl4030_usb_write(twl, TWL4030_USB_CARKIT_ANA_CTRL,
> +		twl4030_usb_read(twl, TWL4030_USB_CARKIT_ANA_CTRL) |
> +		TWL4030_USB_SEL_MADC_MCPC);
> +

shouldn't this be done is the adc driver?

>  	return 0;
>  }
>  
> 

-- 

Peter Meerwald
+43-664-2444418 (mobile)

[PATCH] [TWL4030 MADC] Fix ADC[3:6] readings

[Adam Lee]

Hi Peter, I sent a V2 with corrected wording. My bad!

And yes I agree that register setting should be done in the ADC driver.
Let me see what I can do, and will report back.

Thanks,

Adam

On Mon, Jul 20, 2015 at 11:54 AM, Peter Meerwald <pmeerw@pmeerw.net> wrote:
> On Mon, 20 Jul 2015, Adam YH Lee wrote:
>
>> MADC[3:6] reads incorrect values without these two following changes:
>>
>> - enable the 3v1 bias regulator for ADC[3:6]
>> - configure ADC[3:6] lines as input, not as USB
>
> comments below
>
>> Signed-off-by: Adam YH Lee <adam.yh.lee@gmail.com>
>> ---
>>  drivers/iio/adc/twl4030-madc.c | 14 ++++++++++++++
>>  drivers/phy/phy-twl4030-usb.c  |  7 +++++++
>>  2 files changed, 21 insertions(+)
>>
>> diff --git a/drivers/iio/adc/twl4030-madc.c b/drivers/iio/adc/twl4030-madc.c
>> index 94c5f05..b5020ab 100644
>> --- a/drivers/iio/adc/twl4030-madc.c
>> +++ b/drivers/iio/adc/twl4030-madc.c
>> @@ -45,6 +45,7 @@
>>  #include <linux/types.h>
>>  #include <linux/gfp.h>
>>  #include <linux/err.h>
>> +#include <linux/regulator/consumer.h>
>>
>>  #include <linux/iio/iio.h>
>>
>> @@ -52,6 +53,7 @@
>>   * struct twl4030_madc_data - a container for madc info
>>   * @dev:             Pointer to device structure for madc
>>   * @lock:            Mutex protecting this data structure
>> + * @regulator:               Pointer to bias regulator for madc
>>   * @requests:                Array of request struct corresponding to SW1, SW2 and RT
>>   * @use_second_irq:  IRQ selection (main or co-processor)
>>   * @imr:             Interrupt mask register of MADC
>> @@ -60,6 +62,7 @@
>>  struct twl4030_madc_data {
>>       struct device *dev;
>>       struct mutex lock;      /* mutex protecting this data structure */
>> +     struct regulator *usb3v1;
>>       struct twl4030_madc_request requests[TWL4030_MADC_NUM_METHODS];
>>       bool use_second_irq;
>>       u8 imr;
>> @@ -848,6 +851,14 @@ static int twl4030_madc_probe(struct platform_device *pdev)
>>               goto err_i2c;
>>       }
>>
>> +     madc->usb3v1 = devm_regulator_get(madc->dev, "vusb3v1");
>> +     if (IS_ERR(madc->usb3v1))
>> +             return -ENODEV;
>> +
>> +     ret = regulator_enable(madc->usb3v1);
>> +     if (ret)
>> +             dev_err(madc->dev, "could not be enable 3v1 bias regulator\n");
>
> please fix wording, "could not enable usb 3v1 bias regulator" probably
>
>> +
>>       return 0;
>>
>>  err_i2c:
>> @@ -867,6 +878,9 @@ static int twl4030_madc_remove(struct platform_device *pdev)
>>       twl4030_madc_set_current_generator(madc, 0, 0);
>>       twl4030_madc_set_power(madc, 0);
>>
>> +     regulator_disable(madc->usb3v1);
>> +     regulator_put(madc->usb3v1);
>> +
>>       return 0;
>>  }
>>
>> diff --git a/drivers/phy/phy-twl4030-usb.c b/drivers/phy/phy-twl4030-usb.c
>> index 7b04bef..88fc7d7 100644
>> --- a/drivers/phy/phy-twl4030-usb.c
>> +++ b/drivers/phy/phy-twl4030-usb.c
>> @@ -144,6 +144,9 @@
>>  #define PMBR1                                0x0D
>>  #define GPIO_USB_4PIN_ULPI_2430C     (3 << 0)
>>
>> +#define TWL4030_USB_SEL_MADC_MCPC    (1<<3)
>> +#define TWL4030_USB_CARKIT_ANA_CTRL  0xBB
>> +
>>  struct twl4030_usb {
>>       struct usb_phy          phy;
>>       struct device           *dev;
>> @@ -459,6 +462,10 @@ static int twl4030_phy_power_on(struct phy *phy)
>>               twl4030_i2c_access(twl, 0);
>>       schedule_delayed_work(&twl->id_workaround_work, 0);
>>
>> +     twl4030_usb_write(twl, TWL4030_USB_CARKIT_ANA_CTRL,
>> +             twl4030_usb_read(twl, TWL4030_USB_CARKIT_ANA_CTRL) |
>> +             TWL4030_USB_SEL_MADC_MCPC);
>> +
>
> shouldn't this be done is the adc driver?
>
>>       return 0;
>>  }
>>
>>
>
> --
>
> Peter Meerwald
> +43-664-2444418 (mobile)