[U-Boot] [PATCH v2 u-boot 1/2] reset: Add get/assert/deassert/release for bulk of reset signals

Neil Armstrong narmstrong at baylibre.com
Thu Apr 12 08:14:57 UTC 2018


On 11/04/2018 17:49, Jean-Jacques Hiblot wrote:
> Hi Neil,
> 
> while trying to test your patches on dwc3, I ran into a compilation issue.
> 
> On 03/04/2018 11:40, Neil Armstrong wrote:
>> This patch adds a "bulk" API to the reset API in order to get/deassert/
>> assert/release a group of reset signals associated with a device.
>>
>> This bulk API will avoid adding a copy of the same code to manage
>> a group of reset signals in drivers.
>>
>> Signed-off-by: Neil Armstrong <narmstrong at baylibre.com>
>> ---
>>   drivers/reset/reset-uclass.c | 60 +++++++++++++++++++++++++++
>>   include/reset.h              | 99 ++++++++++++++++++++++++++++++++++++++++++++
>>   2 files changed, 159 insertions(+)
>>
>> diff --git a/drivers/reset/reset-uclass.c b/drivers/reset/reset-uclass.c
>> index 307a297..9a5c9c9 100644
>> --- a/drivers/reset/reset-uclass.c
>> +++ b/drivers/reset/reset-uclass.c
>> @@ -81,6 +81,40 @@ int reset_get_by_index(struct udevice *dev, int index,
>>       return 0;
>>   }
>>   +int reset_get_bulk(struct udevice *dev, struct reset_ctl_bulk *bulk)
>> +{
>> +    int i, ret, err, count;
>> +   
>> +    bulk->count = 0;
>> +
>> +    count = dev_count_phandle_with_args(dev, "resets", "#reset-cells");
>> +    if (!count)
>> +        return 0;
>> +
>> +    bulk->resets = devm_kcalloc(dev, count, sizeof(struct reset_ctl),
>> +                    GFP_KERNEL);
>> +    if (!bulk->resets)
>> +        return -ENOMEM;
>> +
>> +    for (i = 0; i < count; i++) {
>> +        ret = reset_get_by_index(dev, i, &bulk->resets[i]);
>> +        if (ret < 0)
>> +            goto bulk_get_err;
>> +
>> +        ++bulk->count;
>> +    }
>> +
>> +    return 0;
>> +
>> +bulk_get_err:
>> +    err = reset_release_all(bulk->resets, bulk->count);
>> +    if (err)
>> +        debug("%s: could release all resets for %p\n",
>> +              __func__, dev);
>> +
>> +    return ret;
>> +}
>> +
>>   int reset_get_by_name(struct udevice *dev, const char *name,
>>                struct reset_ctl *reset_ctl)
>>   {
>> @@ -126,6 +160,19 @@ int reset_assert(struct reset_ctl *reset_ctl)
>>       return ops->rst_assert(reset_ctl);
>>   }
>>   +int reset_assert_bulk(struct reset_ctl_bulk *bulk)
>> +{
>> +    int i, ret;
>> +
>> +    for (i = 0; i < bulk->count; i++) {
>> +        ret = reset_assert(&bulk->resets[i]);
>> +        if (ret < 0)
>> +            return ret;
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>>   int reset_deassert(struct reset_ctl *reset_ctl)
>>   {
>>       struct reset_ops *ops = reset_dev_ops(reset_ctl->dev);
>> @@ -135,6 +182,19 @@ int reset_deassert(struct reset_ctl *reset_ctl)
>>       return ops->rst_deassert(reset_ctl);
>>   }
>>   +int reset_deassert_bulk(struct reset_ctl_bulk *bulk)
>> +{
>> +    int i, ret;
>> +
>> +    for (i = 0; i < bulk->count; i++) {
>> +        ret = reset_deassert(&bulk->resets[i]);
>> +        if (ret < 0)
>> +            return ret;
>> +    }
>> +
>> +    return 0;
>> +}
>> +
>>   int reset_release_all(struct reset_ctl *reset_ctl, int count)
>>   {
>>       int i, ret;
>> diff --git a/include/reset.h b/include/reset.h
>> index 7185ade..d38f176 100644
>> --- a/include/reset.h
>> +++ b/include/reset.h
>> @@ -60,6 +60,24 @@ struct reset_ctl {
>>       unsigned long id;
>>   };
>>   +/**
>> + * struct reset_ctl_bulk - A handle to (allowing control of) a bulk of reset
>> + * signals.
>> + *
>> + * Clients provide storage for the reset control bulk. The content of the
>> + * structure is managed solely by the reset API. A reset control bulk struct is
>> + * initialized by "get"ing the reset control bulk struct.
>> + * The reset control bulk struct is passed to all other bulk reset APIs to apply
>> + * the API to all the reset signals in the bulk struct.
>> + *
>> + * @resets: An array of reset signal handles handles.
>> + * @count: The number of reset signal handles in the reset array.
>> + */
>> +struct reset_ctl_bulk {
>> +    struct reset_ctl *resets;
>> +    unsigned int count;
>> +};
>> +
>>   #ifdef CONFIG_DM_RESET
>>   /**
>>    * reset_get_by_index - Get/request a reset signal by integer index.
>> @@ -81,6 +99,22 @@ int reset_get_by_index(struct udevice *dev, int index,
>>                  struct reset_ctl *reset_ctl);
>>     /**
>> + * reset_get_bulk - Get/request all reset signals of a device.
>> + *
>> + * This looks up and requests all reset signals of the client device; each
>> + * device is assumed to have n reset signals associated with it somehow,
>> + * and this function finds and requests all of them in a separate structure.
>> + * The mapping of client device reset signals indices to provider reset signals
>> + * may be via device-tree properties, board-provided mapping tables, or some
>> + * other mechanism.
>> + *
>> + * @dev:    The client device.
>> + * @bulk    A pointer to a reset control bulk struct to initialize.
>> + * @return 0 if OK, or a negative error code.
>> + */
>> +int reset_get_bulk(struct udevice *dev, struct reset_ctl_bulk *bulk);
>> +
>> +/**
>>    * reset_get_by_name - Get/request a reset signal by name.
>>    *
>>    * This looks up and requests a reset signal. The name is relative to the
>> @@ -132,6 +166,21 @@ int reset_free(struct reset_ctl *reset_ctl);
>>   int reset_assert(struct reset_ctl *reset_ctl);
>>     /**
>> + * reset_assert_bulk - Assert all reset signals in a reset control bulk struct.
>> + *
>> + * This function will assert the specified reset signals in a reset control
>> + * bulk struct, thus resetting the affected HW module(s). Depending on the
>> + * reset controller hardware, the reset signals will either stay asserted
>> + * until reset_deassert_bulk() is called, or the hardware may autonomously
>> + * clear the reset signals itself.
>> + *
>> + * @bulk:    A reset control bulk struct that was previously successfully
>> + *        requested by reset_get_bulk().
>> + * @return 0 if OK, or a negative error code.
>> + */
>> +int reset_assert_bulk(struct reset_ctl_bulk *bulk);
>> +
>> +/**
>>    * reset_deassert - Deassert a reset signal.
>>    *
>>    * This function will deassert the specified reset signal, thus releasing the
>> @@ -145,6 +194,20 @@ int reset_assert(struct reset_ctl *reset_ctl);
>>   int reset_deassert(struct reset_ctl *reset_ctl);
>>     /**
>> + * reset_deassert_bulk - Deassert all reset signals in a reset control bulk
>> + * struct.
>> + *
>> + * This function will deassert the specified reset signals in a reset control
>> + * bulk struct, thus releasing the affected HW modules() from reset, and
>> + * allowing them to continue normal operation.
>> + *
>> + * @bulk:    A reset control bulk struct that was previously successfully
>> + *        requested by reset_get_bulk().
>> + * @return 0 if OK, or a negative error code.
>> + */
>> +int reset_deassert_bulk(struct reset_ctl_bulk *bulk);
>> +
>> +/**
>>    * reset_release_all - Assert/Free an array of previously requested resets.
>>    *
>>    * For each reset contained in the reset array, this function will check if
>> @@ -156,6 +219,23 @@ int reset_deassert(struct reset_ctl *reset_ctl);
>>    * @return 0 if OK, or a negative error code.
>>    */
>>   int reset_release_all(struct reset_ctl *reset_ctl, int count);
>> +
>> +/**
>> + * reset_release_bulk - Assert/Free an array of previously requested reset
>> + * signals in a reset control bulk struct.
>> + *
>> + * For each reset contained in the reset control bulk struct, this function
>> + * will check if reset has been previously requested and then will assert
>> + * and free it.
>> + *
>> + * @bulk:    A reset control bulk struct that was previously successfully
>> + *        requested by reset_get_bulk().
>> + * @return 0 if OK, or a negative error code.
>> + */
>> +static inline int reset_release_bulk(struct reset_ctl_bulk *bulk)
>> +{
>> +    return reset_release_all(bulk->resets, bulk->count);
>> +}
>>   #else
>>   static inline int reset_get_by_index(struct udevice *dev, int index,
>>                        struct reset_ctl *reset_ctl)
>> @@ -163,6 +243,11 @@ static inline int reset_get_by_index(struct udevice *dev, int index,
>>       return -ENOTSUPP;
>>   }
>>   +static inline int reset_get_bulk(struct udevice *dev, struct clk_bulk *bulk)
> Should be struct reset_ctl_bulk instead of struct clk_bulk
>> +{
>> +    return -ENOTSUPP;
>> +}
>> +
>>   static inline int reset_get_by_name(struct udevice *dev, const char *name,
>>                       struct reset_ctl *reset_ctl)
>>   {
>> @@ -179,16 +264,30 @@ static inline int reset_assert(struct reset_ctl *reset_ctl)
>>       return 0;
>>   }
>>   +static inline int reset_assert_bulk(struct reset_ctl_bulk *bulk)
>> +{
>> +    return 0;
>> +}
>> +
>>   static inline int reset_deassert(struct reset_ctl *reset_ctl)
>>   {
>>       return 0;
>>   }
>>   +static inline int reset_deassert_bulk(struct reset_ctl_bulk *bulk)
>> +{
>> +    return 0;
>> +}
>> +
>>   static inline int reset_release_all(struct reset_ctl *reset_ctl, int count)
>>   {
>>       return 0;
>>   }
>>   +static inline int reset_release_bulk(struct clk_bulk *bulk)
> ditto.
> 
> Jean-Jacques
>> +{
>> +    return 0;
>> +}
>>   #endif
>>     #endif
> 

You are right, I will push a fix ASAP.

Neil


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