On Wed, May 9, 2018 at 1:20 PM, Siva Durga Prasad Paladugu <siva...@xilinx.com> wrote: > > Hi, > >> -----Original Message----- >> From: Jagan Teki [mailto:jagannadh.t...@gmail.com] >> Sent: Wednesday, May 09, 2018 1:12 PM >> To: Siva Durga Prasad Paladugu <siva...@xilinx.com> >> Cc: Jagan Teki <ja...@amarulasolutions.com>; U-Boot-Denx <u- >> b...@lists.denx.de>; michal.si...@xilinx.com >> Subject: Re: [U-Boot] [PATCH v3 1/2] spi: zynqmp_gqspi: Add support for >> ZynqMP qspi driver >> >> On Wed, May 9, 2018 at 12:33 PM, Siva Durga Prasad Paladugu >> <siva...@xilinx.com> wrote: >> > Hi Jagan, >> > >> >> -----Original Message----- >> >> From: Jagan Teki [mailto:ja...@amarulasolutions.com] >> >> Sent: Wednesday, May 09, 2018 12:01 PM >> >> To: Siva Durga Prasad Paladugu <siva...@xilinx.com> >> >> Cc: U-Boot-Denx <u-boot@lists.denx.de>; michal.si...@xilinx.com >> >> Subject: Re: [PATCH v3 1/2] spi: zynqmp_gqspi: Add support for >> ZynqMP >> >> qspi driver >> >> >> >> On Tue, May 8, 2018 at 3:43 PM, Siva Durga Prasad Paladugu >> >> <siva.durga.palad...@xilinx.com> wrote: >> >> > This patch adds qspi driver support for ZynqMP SoC. This driver is >> >> > responsible for communicating with qspi flash devices. >> >> > >> >> > Signed-off-by: Siva Durga Prasad Paladugu >> >> > <siva.durga.palad...@xilinx.com> >> >> > --- >> >> > Changes for v3: >> >> > - Renamed all macros, functions, files and configs as per comment >> >> > - Used wait_for_bit wherever required >> >> > - Removed unnecessary header inclusion >> >> > >> >> > Changes for v2: >> >> > - Rebased on top of latest master >> >> > - Moved macro definitions to .h file as per comment >> >> > - Fixed magic values with macros as per comment >> >> > --- >> >> > arch/arm/include/asm/arch-zynqmp/zynqmp_gqspi.h | 154 ++++++ >> >> > drivers/spi/Kconfig | 7 + >> >> > drivers/spi/Makefile | 1 + >> >> > drivers/spi/zynqmp_gqspi.c | 670 >> >> ++++++++++++++++++++++++ >> >> > 4 files changed, 832 insertions(+) create mode 100644 >> >> > arch/arm/include/asm/arch- >> >> zynqmp/zynqmp_gqspi.h >> >> > create mode 100644 drivers/spi/zynqmp_gqspi.c >> >> > >> >> > diff --git a/arch/arm/include/asm/arch-zynqmp/zynqmp_gqspi.h >> >> > b/arch/arm/include/asm/arch-zynqmp/zynqmp_gqspi.h >> >> >> >> already asked you to move this header code in driver .c file >> > >> > You might have missed my reply to your earlier comment on this. These >> > were moved to .h based on comment from Lukasz in v1. >> > I don’t have any issue in having them anywhere. Let me know your choice. >> >> I'm trying to align Linux code, better to move like that and make sure to use >> similar macros. >> >> > > > [snip] > >> >> > +static void zynqmp_qspi_genfifo_cmd(struct zynqmp_qspi_priv >> *priv) { >> >> > + u8 command = 1; >> >> > + u32 gen_fifo_cmd; >> >> > + u32 bytecount = 0; >> >> > + >> >> > + while (priv->len) { >> >> > + gen_fifo_cmd = zynqmp_qspi_bus_select(priv); >> >> > + gen_fifo_cmd |= GQSPI_GFIFO_TX; >> >> > + >> >> > + if (command) { >> >> > + command = 0; >> >> > + last_cmd = *(u8 *)priv->tx_buf; >> >> > + } >> >> >> >> don't understand this code can you explain? command assigned 1 it >> >> will not updated anywhere? >> > >> > I want to store last command sent. As the first byte in loop only >> > contains command, it ensures it fills only for one time and next time it >> may contain data to be sent along with command. >> > Command initialized to 1 while declaring it above(u8 command = 1). >> >> Ok the first TX buf has command and reused in tx and rx fifo, how come to >> use use same in rx fifo? why is is last_cmd it is first_cmd? > > This holds the command that was sent last to the device before we use in > tx/rx fill, hence used this name.
ie. what I wonder, usually the spi transfer start with cmd + data in that case it would be the first command, did gqspi work reverse way? Jagan. _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot
