Re: [PATCH 2/3] mtd: spi-nor: core code for the Altera Quadspi Flash Controller v2

[Marek Vasut]

On 06/27/2017 07:26 PM, matthew.gerlach@xxxxxxxxxxxxxxx wrote:

[...]

>>>>> +#ifndef __ALTERA_QUADSPI_H
>>>>> +#define __ALTERA_QUADSPI_H
>>>>> +
>>>>> +#include <linux/device.h>
>>>>> +
>>>>> +#define ALTERA_QUADSPI_FL_BITREV_READ BIT(0)
>>>>> +#define ALTERA_QUADSPI_FL_BITREV_WRITE BIT(1)
>>>>> +
>>>>> +#define ALTERA_QUADSPI_MAX_NUM_FLASH_CHIP 3
>>>>> +
>>>>> +int altera_quadspi_create(struct device *dev, void __iomem *csr_base,
>>>>> +              void __iomem *data_base, void __iomem *window_reg,
>>>>> +              size_t window_size, u32 flags);
>>>>> +
>>>>> +int altera_qspi_add_bank(struct device *dev,
>>>>> +             u32 bank, struct device_node *np);
>>>>> +
>>>>> +int altera_quadspi_remove_banks(struct device *dev);
>>>>
>>>> Why is this header needed at all ?
>>>
>>> This header is needed because of the very different ways
>>> FPGAs can be used with a processor running Linux.  In the case of a
>>> soft processor in the FPGA or an ARM connected to a FPGA, this header
>>> is not necessary because device trees are used to probe the driver.
>>> However, if the FPGA is on a PCIe card connected to an x86, device trees
>>> are not generally used, and the pcie driver must enumerate the
>>> "sub-driver".
>>
>> But we don't support that later part, do we ?
> 
> There is currently v2 patch set for the intel-fpga PCIe driver being
> reviewed where I am adding support for version 2 of the Altera Quadspi
> controller.

It'd be real nice to mention that in the cover letter with a link to
that patchset , otherwise it's real hard to understand why you did this.

> This technique of separating core driver code from platform/device tree
> code has been reviewed and accepted for the Altera Partial
> Reconfiguration IP, Altera Freeze Bridge, and the fpga region.

-- 
Best regards,
Marek Vasut