Re: [PATCH v3 2/2] cap11xx: add LED support

[Jacek Anaszewski <j.anaszewski@samsung.com>]

On 06/15/2015 10:56 AM, Matt Ranostay wrote:
> On Mon, Jun 15, 2015 at 1:15 AM, Jacek Anaszewski
> <j.anaszewski@samsung.com> wrote:
>> Hi Matt,
>>
>>
>> On 06/13/2015 06:17 AM, Matt Ranostay wrote:
>>>
>>> Several cap11xx variants have LEDs that be can be controlled, this
>>> patchset implements this functionality.
>>>
>>> Signed-off-by: Matt Ranostay <mranostay@gmail.com>
>>> ---
>>>    drivers/input/keyboard/cap11xx.c | 121
>>> ++++++++++++++++++++++++++++++++++++++-
>>>    1 file changed, 118 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/input/keyboard/cap11xx.c
>>> b/drivers/input/keyboard/cap11xx.c
>>> index f07461a..994154c 100644
>>> --- a/drivers/input/keyboard/cap11xx.c
>>> +++ b/drivers/input/keyboard/cap11xx.c
>>> @@ -12,6 +12,7 @@
>>>    #include <linux/module.h>
>>>    #include <linux/interrupt.h>
>>>    #include <linux/input.h>
>>> +#include <linux/leds.h>
>>>    #include <linux/of_irq.h>
>>>    #include <linux/regmap.h>
>>>    #include <linux/i2c.h>
>>> @@ -47,6 +48,20 @@
>>>    #define CAP11XX_REG_CONFIG2           0x44
>>>    #define CAP11XX_REG_CONFIG2_ALT_POL   BIT(6)
>>>    #define CAP11XX_REG_SENSOR_BASE_CNT(X)        (0x50 + (X))
>>> +#define CAP11XX_REG_LED_POLARITY       0x73
>>> +#define CAP11XX_REG_LED_OUTPUT_CONTROL 0x74
>>> +
>>> +#define CAP11XX_REG_LED_DUTY_CYCLE_1   0x90
>>> +#define CAP11XX_REG_LED_DUTY_CYCLE_2   0x91
>>> +#define CAP11XX_REG_LED_DUTY_CYCLE_3   0x92
>>> +#define CAP11XX_REG_LED_DUTY_CYCLE_4   0x93
>>> +
>>> +#define CAP11XX_REG_LED_DUTY_MIN_MASK  (0x0f)
>>> +#define CAP11XX_REG_LED_DUTY_MIN_MASK_SHIFT    (0)
>>> +#define CAP11XX_REG_LED_DUTY_MAX_MASK  (0xf0)
>>> +#define CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT    (4)
>>> +#define CAP11XX_REG_LED_DUTY_MAX_VALUE (15)
>>> +
>>>    #define CAP11XX_REG_SENSOR_CALIB      (0xb1 + (X))
>>>    #define CAP11XX_REG_SENSOR_CALIB_LSB1 0xb9
>>>    #define CAP11XX_REG_SENSOR_CALIB_LSB2 0xba
>>> @@ -56,10 +71,24 @@
>>>
>>>    #define CAP11XX_MANUFACTURER_ID       0x5d
>>>
>>> +#ifdef CONFIG_LEDS_CLASS
>>> +struct cap11xx_led {
>>> +       struct cap11xx_priv *priv;
>>> +       struct led_classdev cdev;
>>> +       struct work_struct work;
>>> +       u32 reg;
>>> +       enum led_brightness new_brightness;
>>> +};
>>> +#endif
>>> +
>>>    struct cap11xx_priv {
>>>          struct regmap *regmap;
>>>          struct input_dev *idev;
>>>
>>> +#ifdef CONFIG_LEDS_CLASS
>>> +       struct cap11xx_led *leds;
>>> +       int num_leds;
>>> +#endif
>>>          /* config */
>>>          u32 keycodes[];
>>>    };
>>> @@ -67,6 +96,7 @@ struct cap11xx_priv {
>>>    struct cap11xx_hw_model {
>>>          u8 product_id;
>>>          unsigned int num_channels;
>>> +       unsigned int num_leds;
>>>    };
>>>
>>>    enum {
>>> @@ -76,9 +106,9 @@ enum {
>>>    };
>>>
>>>    static const struct cap11xx_hw_model cap11xx_devices[] = {
>>> -       [CAP1106] = { .product_id = 0x55, .num_channels = 6 },
>>> -       [CAP1126] = { .product_id = 0x53, .num_channels = 6 },
>>> -       [CAP1188] = { .product_id = 0x50, .num_channels = 8 },
>>> +       [CAP1106] = { .product_id = 0x55, .num_channels = 6, .num_leds = 0
>>> },
>>> +       [CAP1126] = { .product_id = 0x53, .num_channels = 6, .num_leds = 2
>>> },
>>> +       [CAP1188] = { .product_id = 0x50, .num_channels = 8, .num_leds = 8
>>> },
>>>    };
>>>
>>>    static const struct reg_default cap11xx_reg_defaults[] = {
>>> @@ -111,6 +141,7 @@ static const struct reg_default cap11xx_reg_defaults[]
>>> = {
>>>          { CAP11XX_REG_STANDBY_SENSITIVITY,      0x02 },
>>>          { CAP11XX_REG_STANDBY_THRESH,           0x40 },
>>>          { CAP11XX_REG_CONFIG2,                  0x40 },
>>> +       { CAP11XX_REG_LED_POLARITY,             0x00 },
>>>          { CAP11XX_REG_SENSOR_CALIB_LSB1,        0x00 },
>>>          { CAP11XX_REG_SENSOR_CALIB_LSB2,        0x00 },
>>>    };
>>> @@ -196,6 +227,84 @@ static void cap11xx_input_close(struct input_dev
>>> *idev)
>>>          cap11xx_set_sleep(priv, true);
>>>    }
>>>
>>> +#ifdef CONFIG_LEDS_CLASS
>>> +static void cap11xx_led_work(struct work_struct *work)
>>> +{
>>> +       struct cap11xx_led *led = container_of(work, struct cap11xx_led,
>>> work);
>>> +       struct cap11xx_priv *priv = led->priv;
>>> +       int value = led->new_brightness;
>>> +
>>> +       regmap_update_bits(priv->regmap, CAP11XX_REG_LED_OUTPUT_CONTROL,
>>> +                               BIT(led->reg), !!value ? BIT(led->reg) :
>>> 0);
>>
>>
>> You should set here the brightness value, not only turn the led on/off.
>>
>
> The issue is that the setting is across _ALL_ leds for brightness. But
> on/off state can clearly vary

OK. The comment describing this would be nice here.

>>
>>> +}
>>> +
>>> +static void cap11xx_led_set(struct led_classdev *cdev,
>>> +                          enum led_brightness value)
>>> +{
>>> +       struct cap11xx_led *led = container_of(cdev, struct cap11xx_led,
>>> cdev);
>>> +
>>> +       led->new_brightness = value;
>>> +       schedule_work(&led->work);
>>> +}
>>> +
>>> +static int cap11xx_init_leds(struct device *dev, struct cap11xx_priv
>>> *priv)
>>> +{
>>> +       struct device_node *node = dev->of_node, *child;
>>> +       struct cap11xx_led *led;
>>> +       int cnt = of_get_child_count(node);
>>> +       u32 reg = 0;
>>> +       int error;
>>> +
>>> +       if (!priv->num_leds || !cnt)
>>> +               return 0;
>>> +       if (cnt > priv->num_leds)
>>> +               return -EINVAL;
>>> +
>>> +       led = devm_kcalloc(dev, cnt,
>>> +               sizeof(struct cap11xx_led), GFP_KERNEL);
>>> +       if (!led)
>>> +               return -ENOMEM;
>>> +
>>> +       priv->leds = led;
>>> +       error = of_property_read_u32(node, "linux,led-brightness", &reg);
>>> +       if (error || reg > CAP11XX_REG_LED_DUTY_MAX_VALUE)
>>> +               reg = CAP11XX_REG_LED_DUTY_MAX_VALUE;
>>
>>
>> This property seems to be redundant, as brightness is controlled with
>> 'brightness' sysfs property.
>
> See above comment.
>>
>>> +       error = regmap_update_bits(priv->regmap,
>>> CAP11XX_REG_LED_DUTY_CYCLE_4,
>>> +                               CAP11XX_REG_LED_DUTY_MAX_MASK,
>>> +                               reg <<
>>> CAP11XX_REG_LED_DUTY_MAX_MASK_SHIFT);
>>
>>
>> This probably should be called from brightness_set op.
>
> Above :)
>>
>>> +       if (error)
>>> +               return error;
>>> +
>>> +       for_each_child_of_node(node, child) {
>>> +               led->cdev.name =
>>> +                       of_get_property(child, "label", NULL) ? :
>>> child->name;
>>> +               led->cdev.default_trigger =
>>> +                       of_get_property(child, "linux,default-trigger",
>>> NULL);
>>> +               led->cdev.flags = 0;
>>
>>
>> You don't need to clear flags, as the memory is zeroed by kcalloc.
>>
>>> +               led->cdev.brightness_set = cap11xx_led_set;
>>> +               led->cdev.max_brightness = 1;
>>
>>
>> You introduced linux,led-brightness DT property and defined its range
>> to 0-15 (it should be 1-15 btw), but here you allow for brightness to
>> be max 1.
>>
>>> +               led->cdev.brightness = LED_OFF;
>>
>>> +
>>>
>>> +               error = of_property_read_u32(child, "reg", &reg);
>>> +               if (error != 0 || reg >= priv->num_leds)
>>> +                       continue;
>>> +               led->reg = reg;
>>> +               led->priv = priv;
>>> +
>>> +               error = devm_led_classdev_register(dev, &led->cdev);
>>> +               if (error < 0)
>>> +                       return -EINVAL;
>>> +               INIT_WORK(&led->work, cap11xx_led_work);
>>> +               schedule_work(&led->work);
>>
>>
>> Work queue should be initialized before registration of the LED class
>> device.
> What is the reason for this? Just curious

See Daniel's explanation.

>>
>>> +               led++;
>>> +       };
>>> +
>>> +       return 0;
>>> +}
>>> +#endif
>>> +
>>>    static int cap11xx_i2c_probe(struct i2c_client *i2c_client,
>>>                               const struct i2c_device_id *id)
>>>    {
>>> @@ -316,6 +425,12 @@ static int cap11xx_i2c_probe(struct i2c_client
>>> *i2c_client,
>>>          priv->idev->open = cap11xx_input_open;
>>>          priv->idev->close = cap11xx_input_close;
>>>
>>> +#ifdef CONFIG_LEDS_CLASS
>>> +       priv->num_leds = cap->num_leds;
>>> +       error = cap11xx_init_leds(dev, priv);
>>> +       if (error)
>>> +               return error;
>>> +#endif
>>>          input_set_drvdata(priv->idev, priv);
>>>
>>>          /*
>>>
>>
>>
>> --
>> Best Regards,
>> Jacek Anaszewski
>


-- 
Best Regards,
Jacek Anaszewski