Tool/software:
Hi, TI expert!
I have a development environment for am6234, with our own evaluation board.
The software SDK version is PROCESSOR-SDK-LINUX-RT-AM62X-08.06.00.42.
Our am6234 chip is connected to a flash with the model number w25q128（page size 256 Bytes, erase size 4 KiB, total 16 MiB）, and its schematic diagram is as follows：
The corresponding device tree configuration is as follows：
fss: bus@fc00000 {
compatible = "simple-bus";
reg = <0x00 0x0fc00000 0x00 0x70000>;
#address-cells = <2>;
#size-cells = <2>;
ranges;
ospi0: spi@fc40000 {
compatible = "ti,am654-ospi", "cdns,qspi-nor";
reg = <0x00 0x0fc40000 0x00 0x100>,
<0x05 0x00000000 0x01 0x00000000>;
interrupts = <GIC_SPI 139 IRQ_TYPE_LEVEL_HIGH>;
cdns,fifo-depth = <256>;
cdns,fifo-width = <4>;
cdns,trigger-address = <0x0>;
clocks = <&k3_clks 75 7>;
assigned-clocks = <&k3_clks 75 7>;
assigned-clock-parents = <&k3_clks 75 8>;
assigned-clock-rates = <166666666>;
power-domains = <&k3_pds 75 TI_SCI_PD_EXCLUSIVE>;
#address-cells = <1>;
#size-cells = <0>;
status = "disabled";
};
};
&main_pmx0 {
ospi0_pins_default: ospi0-pins-default {
pinctrl-single,pins = <
AM62X_IOPAD(0x000, PIN_OUTPUT, 0) /* (H24) OSPI0_CLK */
AM62X_IOPAD(0x02c, PIN_OUTPUT, 0) /* (F23) OSPI0_CSn0 */
AM62X_IOPAD(0x00c, PIN_INPUT, 0) /* (E25) OSPI0_D0 */
AM62X_IOPAD(0x010, PIN_INPUT, 0) /* (G24) OSPI0_D1 */
AM62X_IOPAD(0x014, PIN_INPUT, 0) /* (F25) OSPI0_D2 */
AM62X_IOPAD(0x018, PIN_INPUT, 0) /* (F24) OSPI0_D3 */
>;
};
};
&ospi0 {
pinctrl-names = "default";
pinctrl-0 = <&ospi0_pins_default>;
spi_nor_flash: flash@0 {
compatible = "jedec,spi-nor";
reg = <0x0>;
spi-tx-bus-width = <4>;
spi-rx-bus-width = <4>;
spi-max-frequency = <25000000>;
cdns,tshsl-ns = <60>;
cdns,tsd2d-ns = <60>;
cdns,tchsh-ns = <60>;
cdns,tslch-ns = <60>;
cdns,read-delay = <4>;
cdns,phy-mode;
partitions {
compatible = "fixed-partitions";
#address-cells = <1>;
#size-cells = <1>;
partition@0 {
label = "ospi.u-boot";
reg = <0 0x400000>; // 4MB
};
};
};
};
Meanwhile, the configuration of the kernel is as follows：
CONFIG_MTD_SPI_NOR=y # CONFIG_MTD_SPI_NOR_USE_4K_SECTORS is not set
I have two questions：
1.What is the maximum configurable value for SPI max frequency? Is there any limit on the maximum speed？
When I configure SPI max frequency to 52000000Hz, there is an error prompt：
When I configured SPI max frequency to 4166666 Hz, there were no errors：
2.How to improve the write speed of SPI flash？
When the SPI max frequency is configured to 4166666hz, writing 4MB of data to SPI flash takes 28.0269 seconds, as follows：
root@AM62x:~# dmesg |grep spi [ 0.746496] cadence-qspi fc40000.spi: registered master spi5 [ 0.746533] spi spi5.0: setup: ignoring unsupported mode bits 200 [ 0.746542] spi spi5.0: setup mode 0, 8 bits/w, 4166666 Hz max --> 0 [ 0.746860] spi-nor spi5.0: w25q128 (16384 Kbytes) [ 0.746893] 1 fixed-partitions partitions found on MTD device fc40000.spi.0 [ 0.746899] Creating 1 MTD partitions on "fc40000.spi.0": [ 0.746905] 0x000000000000-0x000000400000 : "ospi.u-boot" [ 0.748442] cadence-qspi fc40000.spi: registered child spi5.0 [ 0.749758] omap2_mcspi 4b00000.spi: registered master spi0 [ 0.750860] omap2_mcspi 20100000.spi: registered master spi2 root@AM62x:~# root@AM62x:~# cat /proc/mtd dev: size erasesize name mtd0: 00400000 00010000 "ospi.u-boot" root@AM62x:~# root@AM62x:~# root@AM62x:~# dd if=/dev/urandom of=/dev/mtdblock0 bs=64K count=64 64+0 records in 64+0 records out 4194304 bytes (4.2 MB, 4.0 MiB) copied, 28.1373 s, 149 kB/s root@AM62x:~# dd if=/dev/urandom of=/dev/mtdblock0 bs=1M count=4 4+0 records in 4+0 records out 4194304 bytes (4.2 MB, 4.0 MiB) copied, 28.0269 s, 150 kB/s root@AM62x:~# root@AM62x:~# root@AM62x:~# root@AM62x:~# dd if=/dev/urandom of=test.bin bs=1M count=4 4+0 records in 4+0 records out 4194304 bytes (4.2 MB, 4.0 MiB) copied, 0.0695056 s, 60.3 MB/s root@AM62x:~# root@AM62x:~# dd if=test.bin of=/dev/mtdblock0 bs=1M count=4 4+0 records in 4+0 records out 4194304 bytes (4.2 MB, 4.0 MiB) copied, 28.0232 s, 150 kB/s
When the SPI max frequency is configured to 25000000hz, writing 4MB of data to SPI flash takes 27.1244 seconds, as follows：
root@AM62x:~# dd if=/dev/urandom of=/dev/mtdblock0 bs=1M count=4 4+0 records in 4+0 records out 4194304 bytes (4.2 MB, 4.0 MiB) copied, 27.1244 s, 155 kB/s
It seems that the increase in clock frequency has no effect on the speed of writing flash
Regards,
Li
