Re: [PATCH v3 1/2] mtd: spi-nor: add support to non-uniform SFDP SPI NOR flash memories

[Boris Brezillon <boris.brezillon@bootlin.com>]

On Tue, 23 Oct 2018 10:48:27 +0200
Boris Brezillon <boris.brezillon@bootlin.com> wrote:

> On Tue, 23 Oct 2018 08:18:35 +0000
> Yogesh Narayan Gaur <yogeshnarayan.gaur@nxp.com> wrote:
> 
> > 
> > I have added the prints in m25p80_read() and in flexspi controller prepare_lut and read_rxfifo() func.
> > In these have added prints for data variable of struct op and data which being read by the controller from the flash.
> > 
> > [    2.091467] smpt[0]=[addr_width:00000003, read_dumy:00000008, read_opcode:00000065, data_mask:00000008]          
> > [    2.099113] m25p80_read, nor[op:00000065 addr_width:00000003, dummy:00000008, len:00000001                       
> > [    2.107367] m25p80_read, cmd[opcode:65 bwidth:1] aadr[val:4, nbytes:3, bwidth:1]                                 
> > [    2.114753] m25p80_read, dummy[nbytes:1 bwidth:1] data[bwidth:1, nbytes:1]                                       
> > [    2.121706] nxp_fspi_prepare_lut cmd[opcode:65 bwidth:1] aadr[val:4, nbytes:3, bwidth:1]                         
> > [    2.129786] dummy[nbytes:1 bwidth:1] data[dir:0 bwidth:1, nbytes:1]                                              
> > [    2.136132] nxp-fspi 20c0000.flexspi: CMD[65] lutval[0:8180465        1:24003008      2:0     3:0]               
> > [    2.144223] nxp_fspi_read_rxfifo, ReadData op.buf[0x00]                                         
> > [    2.151004] smpt_read[1] addr[00000004], data_byte[00000000] err:00000000   
> > 
> >                                                   
> > [    2.157782] smpt[2]=[addr_width:00000003, read_dumy:00000008, read_opcode:00000065, data_mask:00000004]  
> > [    2.165429] m25p80_read, nor[op:00000065 addr_width:00000003, dummy:00000008, len:00000001                 
> > [    2.173683] m25p80_read, cmd[opcode:65 bwidth:1] aadr[val:2, nbytes:3, bwidth:1]                       
> > [    2.181068] m25p80_read, dummy[nbytes:1 bwidth:1] data[bwidth:1, nbytes:1]                                     
> > [    2.188021] nxp_fspi_prepare_lut cmd[opcode:65 bwidth:1] aadr[val:2, nbytes:3, bwidth:1]                   
> > [    2.196101] dummy[nbytes:1 bwidth:1] data[dir:0 bwidth:1, nbytes:1]                   
> > [    2.202447] nxp-fspi 20c0000.flexspi: CMD[65] lutval[0:8180465        1:24003008      2:0     3:0]       
> > [    2.210539] nxp_fspi_read_rxfifo, ReadData op.buf[0x02]                            
> > [    2.217319] smpt_read[3] addr[00000002], data_byte[00000002] err:00000000                                                     
> > 
> > 
> > [    2.224098] smpt[4]=[addr_width:00000003, read_dumy:00000008, read_opcode:00000065, data_mask:00000002]                 
> > [    2.231744] m25p80_read, nor[op:00000065 addr_width:00000003, dummy:00000008, len:00000001              
> > [    2.239998] m25p80_read, cmd[opcode:65 bwidth:1] aadr[val:4, nbytes:3, bwidth:1]                     
> > [    2.247383] m25p80_read, dummy[nbytes:1 bwidth:1] data[bwidth:1, nbytes:1]                     
> > [    2.254336] nxp_fspi_prepare_lut cmd[opcode:65 bwidth:1] aadr[val:4, nbytes:3, bwidth:1]            
> > [    2.262416] dummy[nbytes:1 bwidth:1] data[dir:0 bwidth:1, nbytes:1]                                    
> > [    2.268762] nxp-fspi 20c0000.flexspi: CMD[65] lutval[0:8180465        1:24003008      2:0     3:0]         
> > [    2.276854] nxp_fspi_read_rxfifo, ReadData op.buf[0x00]                                     
> > [    2.283634] smpt_read[5] addr[00000004], data_byte[00000000] err:00000000                 
> > 
> > 
> > [    2.290412] spi_nor_get_map_in_use:2915 map_id=0 smpt_len:16 i=:6                                                             
> > [    2.296496] End [addr_width:00000003, read_dumy:00000008, read_opcode:00000065] ReturnVal:00000000                            
> > [    2.305444] spi_nor_parse_smpt:3065                                                                                           
> > [    2.308924] m25p80 spi0.0: failed to parse SMPT (err = -22)                                      
> > 
> >   
> > > 
> > > Next thing you can do is read the CR2NV reg (using the RDAR command) and
> > > check the RL (Read Latency) and AL (Address Length) values.    
> > 
> > Please let me know how to read CR2NV register.  
> 
> Actually, RDAR is already what you use to read the map_id, and we need
> to use it to read the register that contains the number of dummy cycles
> and the number of address bytes to use for RDAR operations. Looks like
> we have a chicken and egg situation here :-).
> 
> Let's try something else:
> 
> 1/ create an u8 array of 16 entries named data_bytes
> 
> for each loop iteration (the first for loop):
> 2/ set ->addr_width to 3 and ->read_dummy to 0
> 3/ call spi_nor_read_raw(nor, addr, ARRAY_SIZE(data_bytes), data_bytes)
> 4/ dump the data_bytes buf
> 5/ set ->addr_width to 4
> 6/ call spi_nor_read_raw(nor, addr, ARRAY_SIZE(data_bytes), data_bytes)
> 7/ dump the data_bytes buf
>    
> If the SPI driver is working correctly, we should be able to figure out
> the right value for ->addr_width and ->read_dummy.

Also, can you add traces in nxp_fspi_read_rxfifo() to print the value
returned by f->read(base + FSPI_RFDR + j * 4) (there are 2 of them).