From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sourav Poddar Date: Mon, 7 Oct 2013 17:58:05 +0530 Subject: [U-Boot] [PATCHv2 5/8] drivers: mtd: spi: Modify read/write command for sfl256s flash. In-Reply-To: References: <1374569979-28660-1-git-send-email-sourav.poddar@ti.com> <1374569979-28660-6-git-send-email-sourav.poddar@ti.com> <51EE91CA.6070709@ti.com> <51F8B47C.6060302@ti.com> <5201E1B1.9020206@ti.com> <520237B1.2050801@ti.com> <520264D6.8080604@ti.com> Message-ID: <5252A8D5.90905@ti.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de On Monday 07 October 2013 05:51 PM, Jagan Teki wrote: > On Wed, Aug 7, 2013 at 8:46 PM, Sourav Poddar wrote: >> On Wednesday 07 August 2013 08:35 PM, Jagan Teki wrote: >>> On Wed, Aug 7, 2013 at 5:34 PM, Sourav Poddar >>> wrote: >>>> Hi Jagan, >>>> >>>> On Wednesday 07 August 2013 05:21 PM, Jagan Teki wrote: >>>>> Hi, >>>>> >>>>> On Wed, Aug 7, 2013 at 11:27 AM, Sourav Poddar >>>>> wrote: >>>>>> Hi Jagan, >>>>>> >>>>>> On Wednesday 31 July 2013 12:23 PM, Sourav Poddar wrote: >>>>>>> Hi Jagan, >>>>>>> On Tuesday 23 July 2013 07:53 PM, Sourav Poddar wrote: >>>>>>>> + jagan, >>>>>>>> >>>>>>>> On Tuesday 23 July 2013 02:29 PM, Sourav Poddar wrote: >>>>>>>>> Reading using the already supported read command is causing >>>>>>>>> regression >>>>>>>>> after 4k bytes, as a result doing a page by page read. Its >>>>>>>>> happening, >>>>>>>>> because >>>>>>>>> ti qpsi controller CS will get de asserted after 4096 bytes. >>>>>>>>> >>>>>>>>> Signed-off-by: Sourav Poddar >>>>>>>>> --- >>>>>>>>> drivers/mtd/spi/spi_flash.c | 32 >>>>>>>>> +++++++++++++++++++++++++++++++- >>>>>>>>> 1 files changed, 31 insertions(+), 1 deletions(-) >>>>>>>>> >>>>>>>>> diff --git a/drivers/mtd/spi/spi_flash.c >>>>>>>>> b/drivers/mtd/spi/spi_flash.c >>>>>>>>> index 6a6fe37..5f8db7b 100644 >>>>>>>>> --- a/drivers/mtd/spi/spi_flash.c >>>>>>>>> +++ b/drivers/mtd/spi/spi_flash.c >>>>>>>>> @@ -303,6 +303,36 @@ int spi_flash_cmd_read_fast(struct spi_flash >>>>>>>>> *flash, u32 offset, >>>>>>>>> else >>>>>>>>> read_len = remain_len; >>>>>>>>> >>>>>>>>> +#ifdef CONFIG_TI_QSPI >>>>>>>>> + unsigned long page_addr, byte_addr, page_size; >>>>>>>>> + size_t chunk_len, actual; >>>>>>>>> + int ret = 0; >>>>>>>>> + >>>>>>>>> + page_size = flash->page_size; >>>>>>>>> + page_addr = offset / page_size; >>>>>>>>> + byte_addr = offset % page_size; >>>>>>>>> + >>>>>>>>> + for (actual = 0; actual< read_len; actual += chunk_len) >>>>>>>>> { >>>>>>>>> + chunk_len = min(read_len - actual, page_size - >>>>>>>>> byte_addr); >>>>>>>>> + >>>>>>>>> + cmd[1] = page_addr>> 8; >>>>>>>>> + cmd[2] = page_addr; >>>>>>>>> + cmd[3] = byte_addr; >>>>>>>>> + >>>>>>>>> + ret = spi_flash_read_common(flash, cmd, sizeof(cmd), >>>>>>>>> + data + actual, chunk_len); >>>>>>>>> + if (ret< 0) { >>>>>>>>> + debug("SF: read failed"); >>>>>>>>> + break; >>>>>>>>> + } >>>>>>>>> + >>>>>>>>> + byte_addr += chunk_len; >>>>>>>>> + if (byte_addr == page_size) { >>>>>>>>> + page_addr++; >>>>>>>>> + byte_addr = 0; >>>>>>>>> + } >>>>>>>>> + } >>>>>>>>> +#else >>>>>>>>> spi_flash_addr(offset, cmd); >>>>>>>>> >>>>>>>>> ret = spi_flash_read_common(flash, cmd, sizeof(cmd), >>>>>>>>> @@ -311,7 +341,7 @@ int spi_flash_cmd_read_fast(struct spi_flash >>>>>>>>> *flash, >>>>>>>>> u32 offset, >>>>>>>>> debug("SF: read failed\n"); >>>>>>>>> break; >>>>>>>>> } >>>>>>>>> - >>>>>>>>> +#endif >>>>>>>>> offset += read_len; >>>>>>>>> len -= read_len; >>>>>>>>> data += read_len; >>>>>>>> Elaborating a bit more on this, >>>>>>>> There is a constrain on our hardware, which goes like this.. >>>>>>>> >>>>>>>> As soon as the words transfered is 4096 bytes, the CS gets deasserted >>>>>>>> automatically. >>>>>>>> As a result of this bottleneck, I am not able to use the current use >>>>>>>> read >>>>>>>> api in mtd framework. >>>>>>>> This requires me to send the read command every time in range upto >>>>>>>> 4096 >>>>>>>> bytes only. >>>>>>>> >>>>>>>> To overcome this, I have updated the mtd read based on TI_QSPI config >>>>>>>> as >>>>>>>> done above. >>>>>>>> >>>>>>>> [Jagan]: >>>>>>>> Do you have any suggestion of dealing this in a better way? >>>>>>>> I don't see a way to get around this apart from updating mtd read >>>>>>>> depending on TI_QSPI config. >>>>>>>> >>>>>>> Any inputs on this? >>>>>>> >>>>>> Any suggestions on the patch? >>>>>> >>>>>> _______________________________________________ >>>>>> U-Boot mailing list >>>>>> U-Boot at lists.denx.de >>>>>> http://lists.denx.de/mailman/listinfo/u-boot >>>>> Yes, this part is pretty much working as with other s25fl. >>>>> Can you point me the respective controller driver for this. >>>>> >>>> Thanks for the response. >>>> >>>> This is the link to uboot patches which I submitted to uboot mailing >>>> list. >>>> >>>> http://patchwork.ozlabs.org/patch/260989/ >>>> http://patchwork.ozlabs.org/patch/260990/ >>>> http://patchwork.ozlabs.org/patch/260991/ >>>> http://patchwork.ozlabs.org/patch/260992/ >>>> http://patchwork.ozlabs.org/patch/260994/ >>>> http://patchwork.ozlabs.org/patch/260993/ >>>> http://patchwork.ozlabs.org/patch/260996/ >>>> http://patchwork.ozlabs.org/patch/260995/ >>>> >>>> Above are the links to uboot patches containing all def configs and uboot >>>> ti >>>> qspi driver. >>>> >>>> As communicated earlier, there is a limitation in our qspi controller >>>> driver, wherein after every >>>> 4096 bytes CS gets de asserted. So, I had to modify the above read >>>> framework >>>> to do a page read. >>>> Need better way to handle this limitation, so that the above patch series >>>> can get upstreamed. >>>> >>>>> Does linux support this ti_qspi, please point the defconfig if you have. >>>>> >>>> Patches for linux is under review and still not mainlined. >>>> https://patchwork.kernel.org/patch/2838342/ >>> Thanks, please give me some time I will look at these and let u know >>> early next week. >>> >> Thanks!! > You still see this issue. > Please ignore this mail thread. This was due to some ip limitation.