Continue of the last post.
Decompress U-boot format initrd
$ mkimage -l uImage
Display image info
$ tail -c+65 < uImage > out
Remove file header
$ tail -c+65 < uImage | gunzip > out
If the file is gzipped, it could be decompressed to get the data.
If it's initramfs, cpio -t < out or pax < out could be used to view the content.
Or try to mount it:
$ mount -ro loop out /mnt
Pack initrd into U-boot format
$ umount /mnt
$ mdconfig -d -u 0
Compress with gzip
$ gzip initrd
Create uboot image
$ mkimage -A arm -T ramdisk -C none -n ramdisk -d initrd.gz ramdisk.uImage
U-Boot related
Create boot script
$ mkimage -A arm -O linux -T script -C none -a 0 -e 0 -n 'Boot script' -d normal.cmd boot.scr
Manual boot
From SD card
fatload mmc 0:1 0x80800000 bin/zImage
fatload mmc 0:1 0x83000000 bin/imx6ul-14x14-evk.dtb
setenv bootargs console=ttymxc0,115200 cma=64M root=/dev/mmcblk0p2 rootwait
bootz 0x80800000 - 0x83000000
Using script on SD
fatload mmc 0 0x80700000 /bin/boot.scr
source 0x80700000
From NAND Flash
nand read 0x80800000 0xa00000 0x800000
nand read 0x83000000 0x700000 0x40000
setenv bootargs console=ttymxc0,115200 cma=64M root=/dev/mtdblock5 rootwait
bootz 0x80800000 - 0x83000000
Disable screen timeout
Screen timeout is provided by VT, which could be disabled by writing control commands:
f = open("/dev/tty0", O_RDWR); write(f, "/033[9;0]", 8); close(f);
Pack SquashFS
Pack the directory into an image
$ mksquashfs /some/dir dir.sqsh
Mount the packed filesystem:
$ mkdir /mnt/dir
$ mount dir.sqsh /mnt/dir -t squashfs -o loop
Directly pack the directory in to target device
$ mksquashfs /some/dir /dev/fd0
ADC
ADC is only available on i.MX6UL and i.MX6SX in the i.MX6 product line.
The device driver is in Device Drivers -> Industrial IO -> Analog to Digital devices -> Freescale vf610. Add the following content in the device tree:
&adc1 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_adc1>; vref-supply = <®_vref_3v3>; status = "okay"; }; pinctrl_adc1: adc1grp { fsl,pins = < MX6UL_PAD_GPIO1_IO07__GPIO1_IO07 0xb0 >; };
Testing
$ cat /sys/bus/iio/devices/iio\:device0/in_voltage7_raw
Beeper
Use the standard pwm-buzzer. Seems like people love abusing pwm-leds or pwm-backlight for beepers, not sure why though.
The driver is located in Device Drivers -> Input Devices -> Misc Devices -> PWM Buzzer. Add the following in the device tree:
beeper { compatible = "pwm-beeper"; pwms = <&pwm6 0 50000>; }; pinctrl_pwm6: pwm6grp { fsl,pins = < MX6UL_PAD_CSI_DATA03__SIM2_PORT1_PD 0xb808 MX6UL_PAD_CSI_DATA04__SIM2_PORT1_CLK 0x11 MX6UL_PAD_CSI_DATA05__SIM2_PORT1_RST_B 0xb810 MX6UL_PAD_CSI_DATA06__SIM2_PORT1_SVEN 0xb810 MX6UL_PAD_CSI_DATA07__SIM2_PORT1_TRXD 0xb811 MX6UL_PAD_CSI_DATA02__GPIO4_IO23 0x3008 MX6UL_PAD_ENET1_TX_EN__PWM6_OUT 0x110b0 >; }; /* Buzzer */ &pwm6 { pinctrl-names = "default"; pinctrl-0 = <&pinctrl_pwm6>; status = "okay"; };
Note that in the kernel of iMX6UL BSP, PWM2-8 didn't have clock allocated, which needs fixing:
@@ -455,8 +455,8 @@ compatible = "fsl,imx6ul-pwm", "fsl,imx27-pwm"; reg = <0x02084000 0x4000>; interrupts = <GIC_SPI 84 IRQ_TYPE_LEVEL_HIGH>; - clocks = <&clks IMX6UL_CLK_DUMMY>, - <&clks IMX6UL_CLK_DUMMY>; + clocks = <&clks IMX6UL_CLK_PWM2>, + <&clks IMX6UL_CLK_PWM2>; clock-names = "ipg", "per"; #pwm-cells = <2>; }; @@ -465,8 +465,8 @@ compatible = "fsl,imx6ul-pwm", "fsl,imx27-pwm"; reg = <0x02088000 0x4000>; interrupts = <GIC_SPI 85 IRQ_TYPE_LEVEL_HIGH>; - clocks = <&clks IMX6UL_CLK_DUMMY>, - <&clks IMX6UL_CLK_DUMMY>; + clocks = <&clks IMX6UL_CLK_PWM3>, + <&clks IMX6UL_CLK_PWM3>; clock-names = "ipg", "per"; #pwm-cells = <2>; }; @@ -475,8 +475,8 @@ compatible = "fsl,imx6ul-pwm", "fsl,imx27-pwm"; reg = <0x0208c000 0x4000>; interrupts = <GIC_SPI 86 IRQ_TYPE_LEVEL_HIGH>; - clocks = <&clks IMX6UL_CLK_DUMMY>, - <&clks IMX6UL_CLK_DUMMY>; + clocks = <&clks IMX6UL_CLK_PWM4>, + <&clks IMX6UL_CLK_PWM4>; clock-names = "ipg", "per"; #pwm-cells = <2>; }; @@ -811,8 +811,8 @@ compatible = "fsl,imx6ul-pwm", "fsl,imx27-pwm"; reg = <0x020f0000 0x4000>; interrupts = <GIC_SPI 114 IRQ_TYPE_LEVEL_HIGH>; - clocks = <&clks IMX6UL_CLK_DUMMY>, - <&clks IMX6UL_CLK_DUMMY>; + clocks = <&clks IMX6UL_CLK_PWM5>, + <&clks IMX6UL_CLK_PWM5>; clock-names = "ipg", "per"; #pwm-cells = <2>; }; @@ -821,8 +821,8 @@ compatible = "fsl,imx6ul-pwm", "fsl,imx27-pwm"; reg = <0x020f4000 0x4000>; interrupts = <GIC_SPI 115 IRQ_TYPE_LEVEL_HIGH>; - clocks = <&clks IMX6UL_CLK_DUMMY>, - <&clks IMX6UL_CLK_DUMMY>; + clocks = <&clks IMX6UL_CLK_PWM6>, + <&clks IMX6UL_CLK_PWM6>; clock-names = "ipg", "per"; #pwm-cells = <2>; }; @@ -831,8 +831,8 @@ compatible = "fsl,imx6ul-pwm", "fsl,imx27-pwm"; reg = <0x020f8000 0x4000>; interrupts = <GIC_SPI 116 IRQ_TYPE_LEVEL_HIGH>; - clocks = <&clks IMX6UL_CLK_DUMMY>, - <&clks IMX6UL_CLK_DUMMY>; + clocks = <&clks IMX6UL_CLK_PWM7>, + <&clks IMX6UL_CLK_PWM7>; clock-names = "ipg", "per"; #pwm-cells = <2>; }; @@ -841,8 +841,8 @@ compatible = "fsl,imx6ul-pwm", "fsl,imx27-pwm"; reg = <0x020fc000 0x4000>; interrupts = <GIC_SPI 117 IRQ_TYPE_LEVEL_HIGH>; - clocks = <&clks IMX6UL_CLK_DUMMY>, - <&clks IMX6UL_CLK_DUMMY>; + clocks = <&clks IMX6UL_CLK_PWM8>, + <&clks IMX6UL_CLK_PWM8>; clock-names = "ipg", "per"; #pwm-cells = <2>; };
Another issue is that usleep_range doesn't work, Use udelay as a replacement, not sure about the implications:
} else { writel(MX3_PWMCR_SWR, imx->mmio_base + MX3_PWMCR); do { - usleep_range(200, 1000); + udelay(10); + //usleep_range(200, 1000); cr = readl(imx->mmio_base + MX3_PWMCR); } while ((cr & MX3_PWMCR_SWR) && (wait_count++ < MX3_PWM_SWR_LOOP));
Boot log should show:
input: pwm-beeper as /devices/platform/beeper/input/input2
To test it:
echo -ne '\007' > /dev/tty0
LED
Simple enough
leds { compatible = "gpio-leds"; pinctrl-names = "default"; pinctrl-0 = <&pinctrl_leds>; heartbeat { label = "heartbeat"; gpios = <&gpio5 5 GPIO_ACTIVE_HIGH>; linux,default-trigger = "heartbeat"; }; }; pwmleds { compatible = "pwm-leds"; green { label = "green"; pwms = <&pwm2 0 100000>; max-brightness = <255>; }; uv { label = "uv"; pwms = <&pwm4 0 100000>; max-brightness = <255>; }; };