Hey,
I am playing a bit around with Zephyr and a custom board. This board is based on a stm32f4 arm and connects a Mircochip Flash(SST26) via spi1. I like to figure out how to setup this spi flash?
Because of lack of knowledge I took a my old Yocto dts file from an other project as template. When doing a own device tree in Linux it looks like:
"""
spi1: spi@f8008000 {
cs-gpios = <&pioC 25 GPIO_ACTIVE_HIGH>;
status = "okay";
m25p80@0 {
compatible = "spansion,s25fl164k";
spi-max-frequency = <50000000>;
reg = <0>;
};
};
"""
Now try something similar in Zephyr OS!
As far as I got:
1.) add in pinmux.c the pin function setup
"""
static const struct pin_config pinconf[] = {
...
// SPI 1 for Flash
#ifdef CONFIG_SPI_STM32
// MEM CS(SS)
{STM32_PIN_PA4, STM32F4_PINMUX_FUNC_PA4_SPI1_NSS},
// MEM CLK
{STM32_PIN_PA5, STM32F4_PINMUX_FUNC_PA5_SPI1_SCK},
// MEM MISO
{STM32_PIN_PA6, STM32F4_PINMUX_FUNC_PA6_SPI1_MISO},
// MEM MOSI
{STM32_PIN_PA7, STM32F4_PINMUX_FUNC_PA7_SPI1_MOSI},
#endif
"""
2.) activate spi1 in myboard.dts
"""
/dts-v1/;
#include <st/stm32f412.dtsi>
/ {
model = "myboard";
compatible = "test,myboard", "st,stm32f412";
chosen {
zephyr,console = &usart1;
zephyr,sram = &sram0;
zephyr,flash = &flash0;
};
soc {
pinctrl: pin-controller@40020000 {
usart1_pins_d: usart1@3 {
rx_tx {
rx = <STM32_PIN_PA10 (STM32_PINMUX_ALT_FUNC_7 | STM32_PUPDR_NO_PULL)>;
tx = <STM32_PIN_PA15 (STM32_PINMUX_ALT_FUNC_7 | STM32_PUSHPULL_PULLUP)>;
};
};
};
};
};
// test uart
&usart1 {
current-speed = <115200>;
pinctrl-0 = <&usart1_pins_d>;
pinctrl-names = "default";
status = "ok";
};
// activate spi1 to access the SST26 flash
&spi1 {
status = "ok";
};
"""
3.) now try to connect the spi with the flash.
3.1) How is the syntax for that?
3.2) Is there a generic driver for that? (like the m25p80 in Linux)
3.2.1) how to write an own driver if there is no driver?
Greetings from UK!
Stefan
