[PATCH mtd] mtd:devices: Add Altera EPCQ Driver

[Viet Nga Dao]

On Tue, Jan 20, 2015 at 10:05 AM, Viet Nga Dao <vndao at altera.com> wrote:
> On Thu, Jan 15, 2015 at 5:27 PM, Viet Nga Dao <vndao at altera.com> wrote:
>> On Tue, Jan 13, 2015 at 11:33 AM, Brian Norris
>> <computersforpeace at gmail.com> wrote:
>>> On Thu, Dec 18, 2014 at 12:23:16AM -0800, vndao at altera.com wrote:
>>>> From: Viet Nga Dao <vndao at altera.com>
>>>>
>>>> Altera EPCQ Controller is a soft IP which enables access to Altera EPCQ and
>>>> EPCS flash chips. This patch adds driver for these devices.
>>>>
>>>> Signed-off-by: Viet Nga Dao <vndao at altera.com>
>>>
>>> This drivers seems awfully similar to (and so I infer it is likely
>>> copy-and-pasted from) m25p80.c / spi-nor.c. Do you think it can be
>>> rewritten as a SPI NOR driver, under drivers/mtd/spi-nor/ ? It looks
>>> like these flash share most (all?) the same basic opcodes.
>>>
>> For Altera EPCQ flashes, almost operations are performed underline
>> hardware. Software only able to perform the following through
>> registers:
>>  -  read status register
>>  -  read id
>>  -  write status registers bit SR_BP0,SR_BP1, SR_BP2,SR_BP3, SR_TB
>> (http://www.altera.com.my/literature/hb/cfg/cfg_cf52012.pdf)
>> For read/write data: all the operations like QUAD_READ/WRITE,
>> FAST_READ/WRITE are handled by hardware as well. From software point
>> of view, there is no difference between these 2 modes.
>> That is why if rewrite the drivers to follow spi-nor structure, it
>> will require extra decoding works for the only few used opcodes.
>>
> Is it OK to remain this driver structure?
Can someone please reply my question as it is been a while?
Viet Nga