[U-Boot] [PATCH] spi: ti_qspi: Use 4-byte opcode for mmap read

[Jagan Teki]

On Thursday 03 December 2015 05:51 PM, Vignesh R wrote:
>
>
> On 12/03/2015 05:25 PM, Jagan Teki wrote:
>> On 23 November 2015 at 17:43, Vignesh R <vigneshr at ti.com> wrote:
>>> ti-qspi driver currently uses 3-byte addressing mode(and opcodes) for
>>> memory-mapped read. This restricts maximum addressable flash size to
>>> 16MB.
>>> Enable the 4-byte addressing(and use 4-byte opcode) for memory-mapped
>>> read to allow access to addresses above 16MB.
>>
>> What about sf side, since we don't have 4-byte opcode support yet?
>>
>
> Well, the sf is accessing >16MB address space using EXT_ADDR registers
> via BAR support (for regular spi read/write). But, memory-mapped read
> doesn't support using EXT_ADDR, hence 4-byte opcode needs to be used for
> during mmap transfers to access >16MB.

So, there is no need to have 4-byte opcode support from sf side for 
memory-mapped reads - true?

>
>>>
>>> Signed-off-by: Ravi Babu <ravibabu at ti.com>
>>> [vigneshr at ti.com: Re-word commit description]
>>> Signed-off-by: Vignesh R <vigneshr at ti.com>
>>>
>>> ---
>>>
>>> Tested on DRA74 EVM with Spansion flash and AM437X IDK EVM with Macronix
>>> flash.
>>>
>>>   drivers/spi/ti_qspi.c | 6 +++---
>>>   1 file changed, 3 insertions(+), 3 deletions(-)
>>>
>>> diff --git a/drivers/spi/ti_qspi.c b/drivers/spi/ti_qspi.c
>>> index 646dd899d3ec..0a032845866d 100644
>>> --- a/drivers/spi/ti_qspi.c
>>> +++ b/drivers/spi/ti_qspi.c
>>> @@ -48,14 +48,14 @@
>>>   #define CORE_CTRL_IO                    0x4a002558
>>>
>>>   #define QSPI_CMD_READ                   (0x3 << 0)
>>> -#define QSPI_CMD_READ_QUAD              (0x6b << 0)
>>> +#define QSPI_CMD_READ_QUAD              (0x6c << 0)
>>>   #define QSPI_CMD_READ_FAST              (0x0b << 0)
>>> -#define QSPI_SETUP0_NUM_A_BYTES         (0x2 << 8)
>>> +#define QSPI_SETUP0_NUM_A_BYTES         (0x3 << 8)
>>>   #define QSPI_SETUP0_NUM_D_BYTES_NO_BITS (0x0 << 10)
>>>   #define QSPI_SETUP0_NUM_D_BYTES_8_BITS  (0x1 << 10)
>>>   #define QSPI_SETUP0_READ_NORMAL         (0x0 << 12)
>>>   #define QSPI_SETUP0_READ_QUAD           (0x3 << 12)
>>> -#define QSPI_CMD_WRITE                  (0x2 << 16)
>>> +#define QSPI_CMD_WRITE                  (0x12 << 16)
>>>   #define QSPI_NUM_DUMMY_BITS             (0x0 << 24)
>>>
>>>   /* ti qspi register set */
>>> --
>>> 2.6.3

thanks!
--
Jagan.