ILI9341V compatability with fb_ili9341.c

[umesh4b4]

Hi Notro,

I have an LCD which is having ili9341V controller and no DC/RS pin on it. I have changed the initialise sequence as per my LCD in fb_ili9341.c. But I could not able to see any output. I see only backlight turned on. I appreciate for your suggestions on what things i need to change to get my LCD to work.

Thanks in Advance.

[notro]

Maybe it's configured for 9-bit mode. The 9th bit being DC. The IM0-3 pins on the controller sets the mode.

[umesh4b4]

Yes it's configured for 9-bit mode. But what changes i need to do in fb_ili9341.c driver file to work for my LCD. There are no IM0-3 pins on my lcd breakout board. I am using fb_ili9341 driver on beaglebone.

Thanks

[notro]

Use buswidth=9 with fbtft_device or buswidth = <9>; if you use Device Tree.

[umesh4b4]

Thanks Notro

I am using Device Tree and changed buswidth = 9 but now i am getting following error message

[ 529.584449] fb_ili9341 fb_ili9341.0: no default functions for regwidth=8 and buswidth=9

when looked into fbtft-core.c i found the following condition if (display->regwidth == 8 && display->buswidth == 9 && par->spi) { par->fbtftops.write_register = fbtft_write_reg8_bus9;

And when i looked into fbtft.h here we are passing NULL for spi_device parameter.

fbtft_probe_common(_display, NULL, pdev);

I have also tried with fbtft_device but i got same error message as above.

[notro]

Is it a SPI or parallel bus (pdev) connected display?

[umesh4b4]

Its SPI device. One more thing fb_ili9341 driver is working fine with Adafruit Display in 8 bit mode. I have just changed buswidth to 9 in the Device tree file that i used with Adafruit display.

[notro]

I don't understand why it doesn't work. spi_device is passed in:

#define FBTFT_REGISTER_DRIVER(_name, _compatible, _display)                \
                                                                           \
static int fbtft_driver_probe_spi(struct spi_device *spi)                  \
{                                                                          \
        return fbtft_probe_common(_display, spi, NULL);                    \
}                                                                          \

[umesh4b4]

Yes, I already saw it. when I use buswidth = 8 with Adafruit display its working without any issue. But Issue is only when buswidth is 9. Here is my DTS file

/ * Pin assignments
 *
 * Module      Connector
 * LITE    <-  P8.19
 * MISO    ->  P9.29
 * SCK     <-  P9.31
 * MOSI    <-  P9.30
 * TFT_CS  <-  P9.28
 * CARD_CS <-  NC
 * D/C     <-  P9.25
 * RESET   <-  P9.27
 *
 */

/ {
    compatible = "ti,beaglebone", "ti,beaglebone-black";
    part-number = "ADAFRUIT-ILI9341";
    version = "00A0";

    /* state the resources this cape uses */
    exclusive-use =
        /* the pin header uses */
        "P8.19",    /* bl: ehrpwm2A */
        "P9.27",    /* lcd: gpio3_19 */
        "P9.25",    /* lcd: gpio3_21 */
        "P9.31",    /* spi: spi1_sclk */
        "P9.29",    /* spi: spi1_d0 */
        "P9.30",    /* spi: spi1_d1 */
        "P9.28",    /* spi: spi1_cs0 */
        /* the hardware IP uses */
        "gpio3_19",
        "gpio3_21",
        "ehrpwm2A",
        "spi1";

    fragment@0 {
        target = <&am33xx_pinmux>;
        __overlay__ {
            pwm_backlight_pins: pinmux_pwm_backlight_pins {
                pinctrl-single,pins = <
                    0x020  0x4      /* gpmc_ad8.gpio0_22 | MODE4 */
                >;
            };

            bone_adafruit_lcd_pins: pinmux_bone_adafruit_lcd_pins {
                pinctrl-single,pins = <
                    0x1a4 0x17      /* mcasp0_fsr.gpio3_19, OUTPUT_PULLUP | MODE7 */
                    0x1ac 0x17      /* mcasp0_ahclkx.gpio3_21, OUTPUT_PULLUP | MODE7 */
                >;
            };

            bone_adafruit_spi1_pins: pinmux_adafruit_spi1_pins {
                pinctrl-single,pins = <
                    0x190 0x33  /* mcasp0_aclkx.spi1_sclk, INPUT_PULLUP | MODE3 */
                    0x194 0x33  /* mcasp0_fsx.spi1_d0, INPUT_PULLUP | MODE3 */
                    0x198 0x13  /* mcasp0_axr0.spi1_d1, OUTPUT_PULLUP | MODE3 */
                    0x19c 0x13  /* mcasp0_ahclkr.spi1_cs0, OUTPUT_PULLUP | MODE3 */
                >;
            };
        };
    };

    fragment@1 {
        target = <&epwmss2>;
        __overlay__ {
            status = "okay";
        };
    };

    fragment@2 {
        target = <&ehrpwm2>;
        __overlay__ {
            status = "okay";
        };
    };

    fragment@3 {
        target = <&spi1>;

        __overlay__ {
            #address-cells = <1>;
            #size-cells = <0>;

            status      = "okay";
            pinctrl-names   = "default";
            pinctrl-0   = <&bone_adafruit_spi1_pins>;

            lcd@0 {
                #address-cells = <1>;
                #size-cells = <0>;

                compatible = "ilitek,ili9341";
                reg = <0>;

                spi-max-frequency = <64000000>;
                spi-cpol;
                spi-cpha;

                rotate = <270>;
                        bgr;
                        fps = <50>;
                        buswidth = <9>;
                        regwidth = <8>;

                pinctrl-names = "default";
                pinctrl-0 = <&bone_adafruit_lcd_pins>;

                reset-gpios = <&gpio4 19 0>;
                dc-gpios = <&gpio4 21 0>;
            };
        };
    };

    fragment@4 {
        target = <&ocp>;

        /* avoid stupid warning */
        #address-cells = <1>;
        #size-cells = <1>;

        __overlay__ {
            adafruit-tft-backlight {
                compatible  = "pwm-backlight";
                pinctrl-names   = "default";
                pinctrl-0   = <&pwm_backlight_pins>;

                pwms = <&ehrpwm2 0 500000 0>;

                pwm-names = "backlight";
                brightness-levels = <0 4 8 16 32 64 128 255>;
                default-brightness-level = <7>; /* index to the array above */
            };
        };
    };
};

[umesh4b4]

Hi Notro,

I am now got frame buffer created and i have figure out the problem. Just look at init function in fbtft.h. Here we are initialising spi device and platform device. When it is creating Platform device i am getting error message. However Frame buffer device is created but I am not getting any data on my LCD.

static int __init fbtft_driver_module_init(void) \ { \ int ret; \ \ ret = spi_register_driver(&fbtft_driver_spi_driver); \ if (ret < 0) \ return ret; \ return platform_driver_register(&fbtft_driver_platform_driver); \ }

[notro]

This is driver registration not device probing.

fb_ili9341 is a (loadable) kernel module that through fbtft_driver_module_init() registers one spi driver and one platform driver. fbtft_device or Device Tree creates a spi or platform device that is passed to the fbtft_driverprobe{spi,pdev} probe function.

If you add debug = <7>; property to DT you'll get a lot of details in the kernel log.

[ivanroberto]

Hi Notro,

I'm have the problem like the umesh4b4, but i'm using fbtft_device. My display controller is ILI9340 and it was configurated (in factory) as 3-wire SPI, so it doesn't have D/C pin. Part number is: TM028HDZ25. I need to change SPI to 9 bits, but i can't do that...

I try to type this line to load de module: sudo modprobe fbtft_device custom name=fb_ili9340 gpios=reset:25,led:18 speed=32000000 buswidth=9 bgr=1

But, no luck...

I have another display with ILI9340 4-wire SPI (with D/C pin), and this command works flawless sudo modprobe fbtft_device name=adafruit22a

I'm pretty shure that these displays is almost the same, the only diference is 4-wire to 3-wire SPI.

Can you help me???

Thanks

[notro]

But, no luck...

This isn't very descriptive, but assuming the driver loads ok, I would try and lower the speed.

[notro]

Closing old issues, reopen if needed.