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HamsterBear Linux ST7789V FBTFT驱动适配

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HamsterBear Linux ST7789V FBTFT驱动适配

修改设备树,在spi0节点下添加

&spi0 {
        pinctrl-names = "default";
        pinctrl-0 = <&spi0_pd_pins>;
        status = "okay";
        spi-max-frequency = <50000000>;

        st7789v: st7789v@0 {
                #address-cells = <1>;
                #size-cells = <1>;
                compatible = "sitronix,st7789v";
                reg = <0>;
                spi-max-frequency = <50000000>;
                rgb;
                buswidth = <8>;
                rotate = <90>;
                fps = <60>;
                spi-cpol;
                spi-cpha;
                reset-gpios = <&pio 4 10 GPIO_ACTIVE_HIGH>;     /* PE10 */
                dc-gpios = <&pio 2 3 GPIO_ACTIVE_LOW>;          /* PC3 */
                debug = <1>;
        };
};

确定内核config打开

需要注意的是,fbtft的驱动只有在内核framebuffer相关驱动开启后才会出现,所以要先开启fb驱动支持
Device Drivers -> Graphics support -> Frame buffer Devices --->,编译进内核
image

可根据需要将控制台映射到fb功能开启
image

这里我同时选择了16色的Tux 启动logo
image

然后寻找fbtft驱动,路径如下:
Device Drivers -> Staging drivers -> Support for small TFT LCD display modules --->,编译进内核
image

修改drivers/staging/fbtft/fb_st7789v.c,如下几处

  1. 修改init函数,该初始化序列参考自厂家
static int init_display(struct fbtft_par *par)
{
        int rc;

        par->fbtftops.reset(par);

        rc = init_tearing_effect_line(par);
        if (rc)
                return rc;

        write_reg(par, 0x11); //Sleep out
        mdelay(120);     //Delay 120ms

        //************* Start Initial Sequence **********//
        write_reg(par, 0x36, 0x00);

        write_reg(par, 0x3A, 0x05);

        write_reg(par, 0xB2,0x0C,0x0C,0x00,0x33,0x33);

        write_reg(par, 0xB7,0x35);

        /* VCOM  = 1.35V */
        write_reg(par, 0xBB, 0x32);

        write_reg(par, 0xC2, 0x01);

        /* GVDD = 4.8V */
        write_reg(par, 0xC3,0x15);

        /* VDX = 0V */
        write_reg(par, 0xC4, 0x20);

        /* FPS = 60Hz */
        write_reg(par, 0xC6,0x0F);

        write_reg(par, 0xD0, 0xA4, 0xA1);

        write_reg(par, 0xE0,0xD0,0x08,0x0E,0x09,0x09,0x05,0x31,0x33,0x48,0x17,0x14,0x15,0x31,0x34);

        write_reg(par, 0xE1,0xD0,0x08,0x0E,0x09,0x09,0x15,0x31,0x33,0x48,0x17,0x14,0x15,0x31,0x34);

        write_reg(par, MIPI_DCS_ENTER_INVERT_MODE);

        write_reg(par, MIPI_DCS_SET_DISPLAY_ON);

        return 0;
}

2, 修改display参数

static struct fbtft_display display = {
        .regwidth = 8,
        .width = 240,
        .height = 280,	/* 根据你的屏幕分辨率确定 */
        .gamma_num = 2,
        .gamma_len = 14,
        .gamma = HSD20_IPS_GAMMA,
        .fbtftops = {
                .init_display = init_display,
                .write_vmem = write_vmem,
                .set_var = set_var,
                .set_gamma = set_gamma,
                .blank = blank,
        },
};

修改drivers/staging/fbtft/fbtft-core.c,如下几处

  1. 添加头文件
#include <linux/of.h>
#include <linux/of_gpio.h>
  1. 修改fbtft_request_one_gpio函数
static int fbtft_request_one_gpio(struct fbtft_par *par,
                                  const char *name, int index,
                                  struct gpio_desc **gpiop)
{
        int ret, gpio;
        struct device *dev = par->info->device;
        struct device_node *np = dev->of_node;

        *gpiop = devm_gpiod_get_index_optional(dev, name, index,
                                               GPIOD_OUT_LOW);

        /* Get GPIO from device tree */
        gpio = of_get_named_gpio(np, name, 0);
        if (gpio < 0) {
                dev_err(dev, "Failed to retrieve %s from dts.\n", name);
                return 0;
        }

        ret = devm_gpio_request_one(dev, gpio, GPIOF_OUT_INIT_HIGH, dev->driver->name);
        if (ret) {
                dev_err(dev, "Failed to request %s GPIO%d\n", name, gpio);
                return -ENODEV;
        }

        *gpiop = gpio_to_desc(gpio);

        fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par, "%s: '%s' GPIO%d\n",
                      __func__, name, gpio);

        return 0;
}
  1. 修改fbtft_request_gpios函数
static int fbtft_request_gpios(struct fbtft_par *par)
{
        int i;
        int ret;

        ret = fbtft_request_one_gpio(par, "reset-gpios", 0, &par->gpio.reset);
        if (ret)
                return ret;
        ret = fbtft_request_one_gpio(par, "dc-gpios", 0, &par->gpio.dc);
        if (ret)
                return ret;
        ret = fbtft_request_one_gpio(par, "rd-gpios", 0, &par->gpio.rd);
        if (ret)
                return ret;
        ret = fbtft_request_one_gpio(par, "wr-gpios", 0, &par->gpio.wr);
        if (ret)
                return ret;
        ret = fbtft_request_one_gpio(par, "cs-gpios", 0, &par->gpio.cs);
        if (ret)
                return ret;
        ret = fbtft_request_one_gpio(par, "latch-gpios", 0, &par->gpio.latch);
        if (ret)
                return ret;
        for (i = 0; i < 16; i++) {
                ret = fbtft_request_one_gpio(par, "db-gpios", i,
                                             &par->gpio.db[i]);
                if (ret)
                        return ret;
                ret = fbtft_request_one_gpio(par, "led-gpios", i,
                                             &par->gpio.led[i]);
                if (ret)
                        return ret;
                ret = fbtft_request_one_gpio(par, "aux-gpios", i,
                                             &par->gpio.aux[i]);
                if (ret)
                        return ret;
        }

        return 0;
}
  1. 修改fbtft_set_win_addr函数
    因为st7789v支持到240x320的分辨率,但是我这块屏是240*280,所以x start和x end都有偏移,
    这个偏移值也是我从厂家源码中参考的。
static void fbtft_set_addr_win(struct fbtft_par *par, int xs, int ys, int xe,
                               int ye)
{
        xs = xs + 20;
        xe = xe + 20;
        write_reg(par, MIPI_DCS_SET_COLUMN_ADDRESS,
                  (xs >> 8) & 0xFF, xs & 0xFF, (xe >> 8) & 0xFF, xe & 0xFF);

        write_reg(par, MIPI_DCS_SET_PAGE_ADDRESS,
                  (ys >> 8) & 0xFF, ys & 0xFF, (ye >> 8) & 0xFF, ye & 0xFF);

        write_reg(par, MIPI_DCS_WRITE_MEMORY_START);
}
  1. 修改fbtft_reset函数
    st7789v是low level reset
static void fbtft_reset(struct fbtft_par *par)
{
        if (!par->gpio.reset)
                return;

        fbtft_par_dbg(DEBUG_RESET, par, "%s()\n", __func__);

        gpiod_set_value_cansleep(par->gpio.reset, 1);
        usleep_range(20, 40);
        gpiod_set_value_cansleep(par->gpio.reset, 0);   /* Low level reset */
        msleep(120);

        gpiod_set_value_cansleep(par->gpio.reset, 1);  /* Activate chip */
}

最后附上两个文件的直观patch

diff --git a/drivers/staging/fbtft/fb_st7789v.c b/drivers/staging/fbtft/fb_st7789v.c
index 861a154144e6..c09063ca3085 100644
--- a/drivers/staging/fbtft/fb_st7789v.c
+++ b/drivers/staging/fbtft/fb_st7789v.c
@@ -150,6 +150,7 @@ static int init_display(struct fbtft_par *par)
        if (rc)
                return rc;

+#if 0
        /* turn off sleep mode */
        write_reg(par, MIPI_DCS_EXIT_SLEEP_MODE);
        mdelay(120);
@@ -213,7 +214,43 @@ static int init_display(struct fbtft_par *par)

        if (HSD20_IPS)
                write_reg(par, MIPI_DCS_ENTER_INVERT_MODE);
+#endif
+       write_reg(par, 0x11); //Sleep out
+       mdelay(120);     //Delay 120ms

+       //************* Start Initial Sequence **********//
+       write_reg(par, 0x36, 0x00);
+
+       write_reg(par, 0x3A, 0x05);
+
+       write_reg(par, 0xB2,0x0C,0x0C,0x00,0x33,0x33);
+
+       write_reg(par, 0xB7,0x35);
+
+       /* VCOM  = 1.35V */
+       write_reg(par, 0xBB, 0x32);
+
+       write_reg(par, 0xC2, 0x01);
+
+       /* GVDD = 4.8V */
+       write_reg(par, 0xC3,0x15);
+
+       /* VDX = 0V */
+       write_reg(par, 0xC4, 0x20);
+
+       /* FPS = 60Hz */
+       write_reg(par, 0xC6,0x0F);
+
+       write_reg(par, 0xD0, 0xA4, 0xA1);
+
+       write_reg(par, 0xE0,0xD0,0x08,0x0E,0x09,0x09,0x05,0x31,0x33,0x48,0x17,0x14,0x15,0x31,0x34);
+
+       write_reg(par, 0xE1,0xD0,0x08,0x0E,0x09,0x09,0x15,0x31,0x33,0x48,0x17,0x14,0x15,0x31,0x34);
+
+       write_reg(par, MIPI_DCS_ENTER_INVERT_MODE);
+
+       write_reg(par, MIPI_DCS_SET_DISPLAY_ON);
+
        return 0;
 }

@@ -369,7 +406,7 @@ static int blank(struct fbtft_par *par, bool on)
 static struct fbtft_display display = {
        .regwidth = 8,
        .width = 240,
-       .height = 320,
+       .height = 280,
        .gamma_num = 2,
        .gamma_len = 14,
        .gamma = HSD20_IPS_GAMMA,
diff --git a/drivers/staging/fbtft/fbtft-core.c b/drivers/staging/fbtft/fbtft-core.c
index 9c4d797e7ae4..f15b8d89afe4 100644
--- a/drivers/staging/fbtft/fbtft-core.c
+++ b/drivers/staging/fbtft/fbtft-core.c
@@ -16,6 +16,8 @@
 #include <linux/slab.h>
 #include <linux/init.h>
 #include <linux/fb.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
 #include <linux/gpio/consumer.h>
 #include <linux/spi/spi.h>
 #include <linux/delay.h>
@@ -74,15 +76,30 @@ static int fbtft_request_one_gpio(struct fbtft_par *par,
                                  const char *name, int index,
                                  struct gpio_desc **gpiop)
 {
+       int ret, gpio;
        struct device *dev = par->info->device;
+       struct device_node *np = dev->of_node;

        *gpiop = devm_gpiod_get_index_optional(dev, name, index,
                                               GPIOD_OUT_LOW);
-       if (IS_ERR(*gpiop))
-               return dev_err_probe(dev, PTR_ERR(*gpiop), "Failed to request %s GPIO\n", name);

-       fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par, "%s: '%s' GPIO\n",
-                     __func__, name);
+       /* Get GPIO from device tree */
+       gpio = of_get_named_gpio(np, name, 0);
+       if (gpio < 0) {
+               dev_err(dev, "Failed to retrieve %s from dts.\n", name);
+               return 0;
+               return 0;
+               return 0;
+       }
+
+       ret = devm_gpio_request_one(dev, gpio, GPIOF_OUT_INIT_HIGH, dev->driver->name);
+       if (ret) {
+               dev_err(dev, "Failed to request %s GPIO%d\n", name, gpio);
+               return -ENODEV;
+       }
+
+       *gpiop = gpio_to_desc(gpio);
+
+       fbtft_par_dbg(DEBUG_REQUEST_GPIOS, par, "%s: '%s' GPIO%d\n",
+                     __func__, name, gpio);

        return 0;
 }
@@ -92,34 +109,34 @@ static int fbtft_request_gpios(struct fbtft_par *par)
        int i;
        int ret;

-       ret = fbtft_request_one_gpio(par, "reset", 0, &par->gpio.reset);
+       ret = fbtft_request_one_gpio(par, "reset-gpios", 0, &par->gpio.reset);
        if (ret)
                return ret;
-       ret = fbtft_request_one_gpio(par, "dc", 0, &par->gpio.dc);
+       ret = fbtft_request_one_gpio(par, "dc-gpios", 0, &par->gpio.dc);
        if (ret)
                return ret;
-       ret = fbtft_request_one_gpio(par, "rd", 0, &par->gpio.rd);
+       ret = fbtft_request_one_gpio(par, "rd-gpios", 0, &par->gpio.rd);
        if (ret)
                return ret;
-       ret = fbtft_request_one_gpio(par, "wr", 0, &par->gpio.wr);
+       ret = fbtft_request_one_gpio(par, "wr-gpios", 0, &par->gpio.wr);
        if (ret)
                return ret;
-       ret = fbtft_request_one_gpio(par, "cs", 0, &par->gpio.cs);
+       ret = fbtft_request_one_gpio(par, "cs-gpios", 0, &par->gpio.cs);
        if (ret)
                return ret;
-       ret = fbtft_request_one_gpio(par, "latch", 0, &par->gpio.latch);
+       ret = fbtft_request_one_gpio(par, "latch-gpios", 0, &par->gpio.latch);
        if (ret)
                return ret;
        for (i = 0; i < 16; i++) {
-               ret = fbtft_request_one_gpio(par, "db", i,
+               ret = fbtft_request_one_gpio(par, "db-gpios", i,
                                             &par->gpio.db[i]);
                if (ret)
                        return ret;
-               ret = fbtft_request_one_gpio(par, "led", i,
+               ret = fbtft_request_one_gpio(par, "led-gpios", i,
                                             &par->gpio.led[i]);
                if (ret)
                        return ret;
-               ret = fbtft_request_one_gpio(par, "aux", i,
+               ret = fbtft_request_one_gpio(par, "aux-gpios", i,
                                             &par->gpio.aux[i]);
                if (ret)
                        return ret;
@@ -203,6 +220,8 @@ EXPORT_SYMBOL(fbtft_register_backlight);
 static void fbtft_set_addr_win(struct fbtft_par *par, int xs, int ys, int xe,
                               int ye)
 {
+       xs = xs + 20;
+       xe = xe + 20;
        write_reg(par, MIPI_DCS_SET_COLUMN_ADDRESS,
                  (xs >> 8) & 0xFF, xs & 0xFF, (xe >> 8) & 0xFF, xe & 0xFF);

@@ -221,10 +240,10 @@ static void fbtft_reset(struct fbtft_par *par)

        gpiod_set_value_cansleep(par->gpio.reset, 1);
        usleep_range(20, 40);
-       gpiod_set_value_cansleep(par->gpio.reset, 0);
+       gpiod_set_value_cansleep(par->gpio.reset, 0);   /* Low level reset */
        msleep(120);

-       gpiod_set_value_cansleep(par->gpio.cs, 1);  /* Activate chip */
+       gpiod_set_value_cansleep(par->gpio.reset, 1);  /* Activate chip */
 }

标签:par,HamsterBear,适配,ST7789V,request,ret,fbtft,write,gpio
来源: https://www.cnblogs.com/hfwz/p/16028968.html