The purpose of this page is to describe the Linux Zynq QSPI driver for Xilinx QSPI PS

Introduction

The purpose of this page is to describe the Linux Zynq QSPI driver for Xilinx QSPI PS

Introduction

HW/IP Features

• 32-bit AXI interface for Linear Addressing mode transfers
• 32-bit APB interface for I/O mode transfers
• Programmable bus protocol for flash memories from Micron and Spansion
• Legacy SPI and scalable performance: 1x, 2x, 4x, 8x I/O widths
• Flexible I/O
• 16 MB addressing per device (32 MB for two devices)
• Device densities up to 128 Mb for I/O and linear mode. Densities greater than 128 Mb are
• supported in I/O mode.
• I/O mode (flash commands and data)
  • Software issues instructions and manages flash operations
  • Interrupts for FIFO control
  • 63-word RxFIFO, 63-word TxFIFO
• Linear addressing mode (executable read accesses)
  • Memory reads and writes are interpreted by the controller
  • AXI port buffers up to four read requests
  • AXI incrementing and wrapping address functions

Features Supported in Driver

• Master mode
• Single, parallel and dual stacked modes
  • Single - One flash device is connected using one slave select, one clock and four data lines.
  • Parallel - Two flash devices are connected using common slave select and separate data lines.
  • Stacked - Two flash devices are connected using separate slave selects and common data lines.
• Driver uses manual chip select and auto start.
• Programmable clock frequency, polarity and phase
• Interrupt support
• Rx bus width of 1 to 4 - supports quad read.
• Tx bus width of 1 to 4 (Current support in custom MTD layer is for bus width of 1)
• Support for SPI NOR flash devices of sizes from 128Mbit to 1Gbit2Gbit.
• Various flash related features supported in customized MTD - such as bank selection, lock/unlock in single, parallel and stacked modes

Missing Features and known Issues/Limitations in Driver

• 4-byte commands are not supported on this controller.
• This driver does not use linear read.
• In dual parallel mode, all register read responses (other than status) are obtained only from lower flash device by the controller.lower flash device by the controller.

Important AR links

• 2023.1/2023.2 - Zynq 7000: Continuous empty flash messages observed when booting in QSPI boot mode using jffs2 root filesystem AR-Link

• 2023.1 - Zynq-7000: QSPI dual-stacked configuration not working properly AR Link

Kernel Configuration Options

Image Removed

Device-tree

qspi: qspi@e000d000 {
    	  compatible = "xlnx,zynq-qspi-1.0";
      clock-namesreg = "ref_clk", "pclk"<0xe000d000 0x1000>;
      clocksinterrupt-parent = <&&clkc 10>, <&&clkc 43>;<0x4>;
      interrupts = <0x0 0x13 0x4>;
      clocks  interrupt-parent = <&&ps7_scugic_0>= <0x1 0xa 0x1 0x2b>;
      interruptsclock-names = <0 19 4>"ref_clk", "pclk";
      is-dualstatus = <0>"okay";
      num#address-cscells = <1><0x1>;
      reg#size-cells = <0xe000d000 0x1000><0x0>;
      xlnx,fb-clk = <0x1>;
      xlnx,qspi-mode = <0x0>u-boot,dm-pre-reloc;
	  num-cs = <0x1>;
      #address-cellsspi-rx-bus-width = <1><0x4>;
      #size-cellsspi-tx-bus-width = <0><0x4>;

      flash@0 {
              compatible = "n25q128", "jedec,spi-nor";
              reg = <0x0>;
              spi-tx-bus-width = <1>;
              spi-rx-bus-width = <4>;
              spi-max-frequency = <50000000>;
              #address-cells = <1>;
              #size-cells = <1>;
              partition@qspi-fsbl-uboot {
                        label = "qspi-fsbl-uboot";
                        reg = <0x0 0x100000>;
              };
              partition@qspi-linux {
                        label = "qspi-linux";
                        reg = <0x100000 0x500000>;
              };
              partition@qspi-device-tree {
                        label = "qspi-device-tree";
                        reg = <0x600000 0x20000>;
              };
              partition@qspi-rootfs {
                        label = "qspi-rootfs";
                        reg = <0x620000 0x5E0000>;
              };
              partition@qspi-bitstream {
                        label = "qspi-bitstream";
                        reg = <0xC00000 0x400000>;
              };
      };
};

Test Procedure

QSPI flash testing with flashcp

dev:    size   erasesize  name
mtd0: 00500000 00001000 "boot"
mtd1: 00020000 00001000 "bootenv"
mtd2: 00a80000 00001000 "kernel"
mtd3: 00060000 00001000 "spare"

4096+0 records in
4096+0 records out
4194304 bytes (4.0MB) copied, 3.227253 seconds, 1.2MB/s

Erasing block: 32/32 (100%)
Writing kb: 4088/4096 (99%)
Verifying kb: 4088/4096 (99%)

QSPI flash testing with jffs2

dev:    size   erasesize  name
mtd0: 00100000 00020000 "qspi-fsbl-uboot"
mtd1: 00500000 00020000 "qspi-linux"
mtd2: 00020000 00020000 "qspi-device-tree"
mtd3: 005e0000 00020000 "qspi-rootfs"
mtd4: 00400000 00020000 "qspi-bitstream"

Erasing 128 Kibyte @ 5c0000 - 97% complete. Cleanmarker written at 5c0000.
Erasing 128 Kibyte @ 5e0000 - 100% complete.

4096+0 records in
4096+0 records out
4194304 bytes (4.0MB) copied, 3.227253 seconds, 1.2MB/s

sample.bin

Expected Output

Expected Output

#List the MTD partitions present and select a partition
# cat /proc/mtd
dev:    size   erasesize  name
mtd0: 00500000 00001000 "boot"
mtd1: 00020000 00001000 "bootenv"
mtd2: 00a80000 00001000 "kernel"
mtd3: 00060000 00001000 "spare"
 

#flash_eraseall -j /dev/mtd3
Erasing 128 Kibyte @ 5c0000 - 97% complete. Cleanmarker written at 5c0000.
Erasing 128 Kibyte @ 5e0000 - 100% complete.
#create a directory
#mkdir qspi_flash0
#mount -t jffs2 /dev/mtdblock3 /qspi_flash0
#diff #dd if=/dev/urandom of=./sample.bin /qspi_flash0/sample.bin
 
 

Performance Details

Single

Dual

Mainline Status

Change Log

2020.1

bs=1024 count=4096
4096+0 records in
4096+0 records out
4194304 bytes (4.0MB) copied, 3.227253 seconds, 1.2MB/s
#cp ./sample.bin /qspi_flash0/
#ls /qspi_flash0
sample.bin
#umount spi_flash0
#mount -t jffs2 /dev/mtdblock3 /qspi_flash0
#diff ./sample.bin /qspi_flash0/sample.bin
 
 

Performance Details

Single

Dual

Mainline Status

Change Log

• 2023.2

  • Summary
    • Fix issue while accessing the upper flash in stacked connection mode
    • Avoid writing EAR register for flashes less than 16MB
  • Commits
    • d607500
    • 9ecc74d

• 2023.1

  • Summary
    • Replace all spi->chip_select and spi->cs_gpiod references with function call
    • Add multi-cs support as per new DT bindings
  • Commits
    • ae655c5
    • 7fe5d3f

• 2022.2

  • Summary
    • Remove multiple instances of clock enable
    • Fix a NULL pointer dereference in zynq_qspi_exec_mem_op()
  • Commits
    • 02d5e2d
    • dae6901

• 2022.1

  • Summary
    • Fix some wrong goto jumps & missing error code
    • Use wait_for_completion_timeout to make zynq_qspi_exec_mem_op not interruptible
    • Fix buffer overflow in zynq_qspi_exec_mem_op
  • Commits
    • f131767
    • 26cfc0d
    • 1a11726