t113 i2c 总线时钟调节不起作用

[efancier]

mangopi dual 的板子，调试触摸屏的时候发现tw2 i2c 调节不生效，无论输入400K还是100K，实际都以1.2M左右运行，查看 /sys目录下和 /proc 目录下i2c 节点的频率都已经是修改过的频率了，请问是否是i2c总线驱动的问题？ 使用的是buidlroot
设备树：

&twi2 {
clock-frequency = <400000>;
pinctrl-0 = <&twi2_pins_a>;
pinctrl-1 = <&twi2_pins_b>;
pinctrl-names = "default", "sleep";
twi_drv_used = <1>;
dmas = <&dma 45>, <&dma 45>;
dma-names = "tx", "rx";
status = "okay";
ctp@14 {
compatible = "allwinner,goodix，gt911";
device_type = "ctp";
reg = <0x14>;
status = "disabled";
ctp_name = "gt9xxnew_ts";
ctp_twi_id = <0x2>;
ctp_twi_addr = <0x14>;
ctp_screen_max_x = <0x320>;
ctp_screen_max_y = <0x1e0>;
ctp_revert_x_flag = <0x0>;
ctp_revert_y_flag = <0x0>;
ctp_exchange_x_y_flag = <0x0>;
ctp_int_port = <&pio PB 2 GPIO_ACTIVE_HIGH>;
ctp_wakeup = <&pio PB 3 GPIO_ACTIVE_HIGH>;
/ctp-supply = <&reg_aldo2>;/
/ctp_power_ldo = <&reg_aldo2>;/
/ctp_power_ldo_vol = <3300>;/
};
};

[efancier]

追踪到驱动程序里面的寄存器读写了，发现这句话
writel(reg_val, i2c->base_addr + reg_clk);
无论往寄存器里面写什么值，i2c 输出时钟频率都不变，可能是写入的值需要符合一定的组合，或者寄存器地址根本就不对？还是硬件有Bug? 原厂的技术工程师能否帮忙看一下

static void sunxi_i2c_clk_write_reg(struct sunxi_i2c *i2c, unsigned int reg_clk,
		unsigned int sclk_freq,
		unsigned char clk_m, unsigned char clk_n,
		unsigned int mask_clk_m, unsigned int mask_clk_n)
{
	unsigned int reg_val = readl(i2c->base_addr + reg_clk);

#if IS_ENABLED(CONFIG_ARCH_SUN50IW10)
	unsigned int duty;
#endif
	dev_dbg(i2c->dev, "reg_clk = 0x%x, clk_m = %u, clk_n = %u,"
		"mask_clk_m = %x, mask_clk_n = %x\n",
		reg_clk, clk_m, clk_n, mask_clk_m, mask_clk_n);
	if (reg_clk == TWI_DRIVER_BUSC) {
		reg_val &= ~(mask_clk_m | mask_clk_n);
		reg_val |= ((clk_m | (clk_n << 4)) << 8);
#if IS_ENABLED(CONFIG_ARCH_SUN50IW10)
		duty = TWI_DRV_CLK_DUTY;
		if (sclk_freq > STANDDARD_FREQ)
			reg_val |= duty;
		else
			reg_val &= ~duty;
#endif
		writel(reg_val, i2c->base_addr + reg_clk);
		dev_dbg(i2c->dev, "reg: 0x%x value: 0x%x\n",
			reg_clk, readl(i2c->base_addr + reg_clk));
		printk("\n clk reg val:%d - reg:%d, m -n %d-%d",reg_val,i2c->base_addr + reg_clk, clk_m, clk_n);
	} else {
		reg_val &= ~(mask_clk_m | mask_clk_n);
		reg_val |= ((clk_m  << 3) | clk_n);
#if IS_ENABLED(CONFIG_ARCH_SUN50IW10)
		duty = TWI_CLK_DUTY;
		if (sclk_freq > STANDDARD_FREQ)
			reg_val |= duty;
		else
			reg_val &= ~duty;
#endif
		writel(reg_val, i2c->base_addr + reg_clk);
		
		dev_dbg(i2c->dev, "reg: 0x%x value: 0x%x\n",
			reg_clk, readl(i2c->base_addr + reg_clk));
	}
}

[duowei1987]

@efancier 在longan下确实是这种情况，而在tina下i2c就是正常的，我也不清楚原因

[suitjune]

@duowei1987 longan sdk是不是有问题，我用PD20 PD21都调不出来I2C。。。。

[efancier]

@duowei1987， 多谢确认这个问题，这个坑也太大了，我试试Tina的 I2c 总线驱动看能不能解决这个问题，现在的方案是用GPIO模拟，速度能到100K左右，暂时对付着驱动GT触摸屏

[suitjune]

我又试了试，可以400K I2C频率啊，longan sdk.

[efancier]

@suitjune ,是buildroot编译的吗？

[suitjune]

@efancier 啥意思？longan sdk不都有自己的SDK的内核？你是指内核是buildroot编译出来的？

[efancier]

@suitjune , 用的这个构建的：
https://github.com/YuzukiHD/Buildroot-YuzukiSBC

[duowei1987]

@efancier 将longan的i2c-sunxi.c和i2c-sunxi.h更换为tina linux的文件就可以了，测试过i2c正常

[efancier]

@duowei1987 ，谢谢！我对比下看看这两个版本的文件有什么不一样。