[01/11] spi: spi-mem: Extend the SPI mem interface to set a custom memory name

Message ID 1527686082-15142-2-git-send-email-frieder.schrempf@exceet.de
State New
Delegated to: Boris Brezillon
Headers show
Series
  • Port the FSL QSPI driver to the SPI framework
Related show

Commit Message

Frieder Schrempf May 30, 2018, 1:14 p.m.
When porting (Q)SPI controller drivers from the MTD layer to the SPI
layer, the naming scheme for the memory devices changes. To be able
to keep compatibility with the old drivers naming scheme, a function
is added to the SPI mem interface to let controller drivers set a
custom name for the memory.

Example for the FSL QSPI driver:

Name with the old driver: 21e0000.qspi,
or with multiple devices: 21e0000.qspi-0, 21e0000.qspi-1, ...

Name with the new driver without spi_mem_get_name: spi4.0

Signed-off-by: Frieder Schrempf <frieder.schrempf@exceet.de>
---
 drivers/spi/spi-mem.c       | 25 +++++++++++++++++++++++++
 include/linux/spi/spi-mem.h |  3 +++
 2 files changed, 28 insertions(+)

Comments

Boris Brezillon May 30, 2018, 2:32 p.m. | #1
Hi Frieder,

On Wed, 30 May 2018 15:14:30 +0200
Frieder Schrempf <frieder.schrempf@exceet.de> wrote:

> When porting (Q)SPI controller drivers from the MTD layer to the SPI
> layer, the naming scheme for the memory devices changes. To be able
> to keep compatibility with the old drivers naming scheme, a function
> is added to the SPI mem interface to let controller drivers set a
> custom name for the memory.
> 
> Example for the FSL QSPI driver:
> 
> Name with the old driver: 21e0000.qspi,
> or with multiple devices: 21e0000.qspi-0, 21e0000.qspi-1, ...
> 
> Name with the new driver without spi_mem_get_name: spi4.0
> 
> Signed-off-by: Frieder Schrempf <frieder.schrempf@exceet.de>
> ---
>  drivers/spi/spi-mem.c       | 25 +++++++++++++++++++++++++
>  include/linux/spi/spi-mem.h |  3 +++
>  2 files changed, 28 insertions(+)
> 
> diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
> index 990770d..5e9af47 100644
> --- a/drivers/spi/spi-mem.c
> +++ b/drivers/spi/spi-mem.c
> @@ -311,6 +311,31 @@ int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
>  EXPORT_SYMBOL_GPL(spi_mem_exec_op);
>  
>  /**
> + * spi_mem_get_name() - Let drivers using the SPI mem interface specify a
> + *			custom name for the memory to avoid compatibility
> + *			issues with ported drivers.
> + * @mem: the SPI memory
> + *
> + * When porting (Q)SPI controller drivers from the MTD layer to the SPI
> + * layer, the naming scheme for the memory devices changes. To be able to
> + * keep compatibility with the old drivers naming scheme, this function can
> + * be used to get a custom name from the controller driver.
> + * If no custom name is available, the name of the SPI device is returned.
> + *
> + * Return: a char array that contains the name for the flash memory
> + */
> +const char *spi_mem_get_name(struct spi_mem *mem)
> +{
> +	struct spi_controller *ctlr = mem->spi->controller;
> +
> +	if (ctlr->mem_ops && ctlr->mem_ops->get_name)
> +		return ctlr->mem_ops->get_name(mem);

Looks like your implementation of ->get_name() in the fsl driver is
allocating a new string each time it's called. I guess other
implementations might be forced to do the same, so maybe it's better to
add a ->name field to struct spi_mem and only call ->get_name() once
when the device is probed. Then spi_mem_get_name() can just be
implemented like this:

const char *spi_mem_get_name(struct spi_mem *mem)
{
	return mem->name;
}

Regards,

Boris

> +
> +	return dev_name(&mem->spi->dev);
> +}
> +EXPORT_SYMBOL_GPL(spi_mem_get_name);
> +
> +/**
>   * spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to
>   *			      match controller limitations
>   * @mem: the SPI memory
> diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h
> index 4fa34a2..f1912d3 100644
> --- a/include/linux/spi/spi-mem.h
> +++ b/include/linux/spi/spi-mem.h
> @@ -178,6 +178,7 @@ struct spi_controller_mem_ops {
>  			    const struct spi_mem_op *op);
>  	int (*exec_op)(struct spi_mem *mem,
>  		       const struct spi_mem_op *op);
> +	const char *(*get_name)(struct spi_mem *mem);
>  };
>  
>  /**
> @@ -236,6 +237,8 @@ bool spi_mem_supports_op(struct spi_mem *mem,
>  int spi_mem_exec_op(struct spi_mem *mem,
>  		    const struct spi_mem_op *op);
>  
> +const char *spi_mem_get_name(struct spi_mem *mem);
> +
>  int spi_mem_driver_register_with_owner(struct spi_mem_driver *drv,
>  				       struct module *owner);
>
Frieder Schrempf May 30, 2018, 3:12 p.m. | #2
Hi Boris,

On 30.05.2018 16:32, Boris Brezillon wrote:
> Hi Frieder,
> 
> On Wed, 30 May 2018 15:14:30 +0200
> Frieder Schrempf <frieder.schrempf@exceet.de> wrote:
> 
>> When porting (Q)SPI controller drivers from the MTD layer to the SPI
>> layer, the naming scheme for the memory devices changes. To be able
>> to keep compatibility with the old drivers naming scheme, a function
>> is added to the SPI mem interface to let controller drivers set a
>> custom name for the memory.
>>
>> Example for the FSL QSPI driver:
>>
>> Name with the old driver: 21e0000.qspi,
>> or with multiple devices: 21e0000.qspi-0, 21e0000.qspi-1, ...
>>
>> Name with the new driver without spi_mem_get_name: spi4.0
>>
>> Signed-off-by: Frieder Schrempf <frieder.schrempf@exceet.de>
>> ---
>>   drivers/spi/spi-mem.c       | 25 +++++++++++++++++++++++++
>>   include/linux/spi/spi-mem.h |  3 +++
>>   2 files changed, 28 insertions(+)
>>
>> diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
>> index 990770d..5e9af47 100644
>> --- a/drivers/spi/spi-mem.c
>> +++ b/drivers/spi/spi-mem.c
>> @@ -311,6 +311,31 @@ int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
>>   EXPORT_SYMBOL_GPL(spi_mem_exec_op);
>>   
>>   /**
>> + * spi_mem_get_name() - Let drivers using the SPI mem interface specify a
>> + *			custom name for the memory to avoid compatibility
>> + *			issues with ported drivers.
>> + * @mem: the SPI memory
>> + *
>> + * When porting (Q)SPI controller drivers from the MTD layer to the SPI
>> + * layer, the naming scheme for the memory devices changes. To be able to
>> + * keep compatibility with the old drivers naming scheme, this function can
>> + * be used to get a custom name from the controller driver.
>> + * If no custom name is available, the name of the SPI device is returned.
>> + *
>> + * Return: a char array that contains the name for the flash memory
>> + */
>> +const char *spi_mem_get_name(struct spi_mem *mem)
>> +{
>> +	struct spi_controller *ctlr = mem->spi->controller;
>> +
>> +	if (ctlr->mem_ops && ctlr->mem_ops->get_name)
>> +		return ctlr->mem_ops->get_name(mem);
> 
> Looks like your implementation of ->get_name() in the fsl driver is
> allocating a new string each time it's called. I guess other
> implementations might be forced to do the same, so maybe it's better to
> add a ->name field to struct spi_mem and only call ->get_name() once
> when the device is probed. Then spi_mem_get_name() can just be
> implemented like this:
> 
> const char *spi_mem_get_name(struct spi_mem *mem)
> {
> 	return mem->name;
> }

Sounds like a good proposal. I will change that.

Thanks,

Frieder

> 
> Regards,
> 
> Boris
> 
>> +
>> +	return dev_name(&mem->spi->dev);
>> +}
>> +EXPORT_SYMBOL_GPL(spi_mem_get_name);
>> +
>> +/**
>>    * spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to
>>    *			      match controller limitations
>>    * @mem: the SPI memory
>> diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h
>> index 4fa34a2..f1912d3 100644
>> --- a/include/linux/spi/spi-mem.h
>> +++ b/include/linux/spi/spi-mem.h
>> @@ -178,6 +178,7 @@ struct spi_controller_mem_ops {
>>   			    const struct spi_mem_op *op);
>>   	int (*exec_op)(struct spi_mem *mem,
>>   		       const struct spi_mem_op *op);
>> +	const char *(*get_name)(struct spi_mem *mem);
>>   };
>>   
>>   /**
>> @@ -236,6 +237,8 @@ bool spi_mem_supports_op(struct spi_mem *mem,
>>   int spi_mem_exec_op(struct spi_mem *mem,
>>   		    const struct spi_mem_op *op);
>>   
>> +const char *spi_mem_get_name(struct spi_mem *mem);
>> +
>>   int spi_mem_driver_register_with_owner(struct spi_mem_driver *drv,
>>   				       struct module *owner);
>>   
>

Patch

diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index 990770d..5e9af47 100644
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -311,6 +311,31 @@  int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
 EXPORT_SYMBOL_GPL(spi_mem_exec_op);
 
 /**
+ * spi_mem_get_name() - Let drivers using the SPI mem interface specify a
+ *			custom name for the memory to avoid compatibility
+ *			issues with ported drivers.
+ * @mem: the SPI memory
+ *
+ * When porting (Q)SPI controller drivers from the MTD layer to the SPI
+ * layer, the naming scheme for the memory devices changes. To be able to
+ * keep compatibility with the old drivers naming scheme, this function can
+ * be used to get a custom name from the controller driver.
+ * If no custom name is available, the name of the SPI device is returned.
+ *
+ * Return: a char array that contains the name for the flash memory
+ */
+const char *spi_mem_get_name(struct spi_mem *mem)
+{
+	struct spi_controller *ctlr = mem->spi->controller;
+
+	if (ctlr->mem_ops && ctlr->mem_ops->get_name)
+		return ctlr->mem_ops->get_name(mem);
+
+	return dev_name(&mem->spi->dev);
+}
+EXPORT_SYMBOL_GPL(spi_mem_get_name);
+
+/**
  * spi_mem_adjust_op_size() - Adjust the data size of a SPI mem operation to
  *			      match controller limitations
  * @mem: the SPI memory
diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h
index 4fa34a2..f1912d3 100644
--- a/include/linux/spi/spi-mem.h
+++ b/include/linux/spi/spi-mem.h
@@ -178,6 +178,7 @@  struct spi_controller_mem_ops {
 			    const struct spi_mem_op *op);
 	int (*exec_op)(struct spi_mem *mem,
 		       const struct spi_mem_op *op);
+	const char *(*get_name)(struct spi_mem *mem);
 };
 
 /**
@@ -236,6 +237,8 @@  bool spi_mem_supports_op(struct spi_mem *mem,
 int spi_mem_exec_op(struct spi_mem *mem,
 		    const struct spi_mem_op *op);
 
+const char *spi_mem_get_name(struct spi_mem *mem);
+
 int spi_mem_driver_register_with_owner(struct spi_mem_driver *drv,
 				       struct module *owner);