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msm8953背光

程序员文章站 2022-07-14 15:51:08
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1、使用PMIC输出的背光，即bl_ctrl_wled背光驱动的方式
使用原理
即可使用PMI8952上的WLED_link模块驱动两组LED灯的。如下：
msm8953背光
而PMI8952上的PMI_MPP3输出的WLED模式PWM输出管脚链接到LCD的背光控制光脚上。如下：
msm8953背光
电路使用方式如下：
msm8953背光
2、背光驱动IC的方式
实现原理：
msm8953背光
msm8953背光
背光驱动方式：
驱动IC使能管脚使用GPIO33和MCU使能与控制。在初期调试的时候，先断开MCU的链接。PWM使用PMI8953上的MPP4输出，如下：
msm8953背光
3、代码中的实现方式
3.1、kernel代码实现方式
其中：
qcom,mdss-dsi-bl-pmic-control-type
“bl_ctrl_pwm”：Backlight controlled by PWM gpio.
“bl_ctrl_wled” ：Backlight controlled by WLED.
“bl_ctrl_dcs” ：Backlight controlled by DCS commands.
WLED方式：
kernel\msm-4.9\arch\arm64\boot\dts\GM620S\dsi-panel-ek79030-1080p-video.dtsi
qcom,mdss-dsi-bl-pmic-control-type = “bl_ctrl_wled”;
qcom,mdss-dsi-bl-min-level = <1>;
qcom,mdss-dsi-bl-max-level = <4095>;
背光驱动IC驱动方式：
qcom,mdss-dsi-bl-pmic-control-type = “bl_ctrl_pwm”;
qcom,mdss-dsi-bl-min-level = <1>;
qcom,mdss-dsi-bl-max-level = <4095>;
qcom,mdss-dsi-bl-pmic-pwm-frequency = <100>;
qcom,mdss-dsi-bl-pmic-bank-select = <0>;
qcom,mdss-dsi-pwm-gpio = <&pm8953_mpps 4 0>;
背光设备树解析：
mdss_dsi_ctrl_probe() ///// kernel/msm-3.18/drivers/video/msm/mdss/mdss_dsi.c
|___mdss_panel_parse_bl_setting() ///// kernel/msm-3.18/drivers/video/msm/mdss/mdss_dsi_panel.c
设置背光亮度代码：
mdss_fb_probe() //// kernel/msm-3.18/drivers/video/msm/mdss/mdss_fb.c
|___mdss_fb_set_bl_brightness()
|___mdss_fb_set_brightness()
|___pdata->set_backlight()
|___ctrl_pdata->panel_data.set_backlight = mdss_dsi_panel_bl_ctrl()
mdss_dsi_panel_bl_ctrl() ///// kernel/msm-3.18/drivers/video/msm/mdss/mdss_dsi_panel.c
背光控制节点：
msm8953背光
msm8953背光
3.2 lk中实现：
bootable\bootloader\lk\dev\gcdb\display\include\panel_ek79030_1080p_video.h
/---------------------------------------------------------------------------/
/* Backlight setting /
/---------------------------------------------------------------------------/
/
uint16_t bl_interface_type;
uint16_t bl_min_level;
uint16_t bl_max_level;
uint16_t bl_step;
uint16_t bl_pmic_controltype;
char *bl_pmic_model;
*/
static struct backlight ek79030_1080p_video_backlight = {
1, 1, 4095, 100, 1, “PMIC_8941”
};
msm8953背光
bootable\bootloader\lk\target\msm8953\target_display.c
bootable\bootloader\lk\dev\gcdb\display\gcdb_display.c
bootable\bootloader\lk\dev\qpnp_wled\qpnp_wled.c
bootable\bootloader\lk\dev\pmic\pm8x41\pm_pwm.c
msm8953背光
4、代码移植
本文中只针对背光驱动IC实现的方式，因为我们发现使用PMI8952的MPP3实现方式时，PWM调整到最大背光的驱动电流还是不够，亮度满足不了需求，而背光驱动IC可以既调节PWM的占空比，要可以调节驱动IC上的电阻来达到调节最大背光亮度。
4.1 lk部分的移植
配置PWM:
bootable\bootloader\lk\dev\gcdb\display\include\panel_ek79030_1080p_video.h

/*---------------------------------------------------------------------------*/
/* Backlight setting                                                         */
/*---------------------------------------------------------------------------*/
/*
uint16_t bl_interface_type;
uint16_t bl_min_level;
uint16_t bl_max_level;
uint16_t bl_step;
uint16_t bl_pmic_controltype;
char     *bl_pmic_model;
*/
static struct backlight ek79030_1080p_video_backlight = {
	1, 1, 4095, 100, 1, "PMIC_8941"
};

配置背光使能GPIO33：
bootable\bootloader\lk\target\msm8953\target_display.c

//blk enable GPIO33
static struct gpio_pin bkl_gpio = {
  //"msmgpio", 59, 3, 1, 0, 1
  "msmgpio", 33, 3, 1, 0, 1
};

将wled驱动模式修改成mpp4的PWM背光IC驱动模式：
bootable\bootloader\lk\target\msm8953\target_display.c

static int pwm_backlight_ctrl(uint8_t enable)
{
	if(enable) {
		pm_pwm_enable(false);
		pm_pwm_config(PWM_DUTY_US, PWM_PERIOD_US);
		pm_pwm_enable(true);
	} else {
		pm_pwm_enable(false);
	}

	return NO_ERROR;
}
//add lizhongyu modify for niou PWM backlight start
static int pwm_backlight_ctrl_niou(uint8_t enable)
{
	struct pm8x41_mpp mpp;
	int rc;
	mpp.base = PM8x41_MMP4_BASE;
	mpp.vin = MPP_VIN3;//MPP_VIN0;
	if (enable) {
		dprintf(INFO, "%s: enable\n", __func__);
			pm_pwm_enable(false);
			rc = pm_pwm_config(PWM_DUTY_US, PWM_PERIOD_US);
			if (rc < 0)
				mpp.mode = MPP_HIGH;
			else {
				mpp.mode = MPP_DTEST2;//MPP_DTEST1;
				pm_pwm_enable(true);
			}
			pm8x41_config_output_mpp(&mpp);
			pm8x41_enable_mpp(&mpp, MPP_ENABLE);
	} else {
		dprintf(INFO, "%s: disable\n", __func__);
			pm_pwm_enable(false);
			pm8x41_enable_mpp(&mpp, MPP_DISABLE);
	}
	mdelay(20);
	return 0;
}
//dd lizhongyu modify for niou PWM backlight end

int target_backlight_ctrl(struct backlight *bl, uint8_t enable)
{
	uint32_t ret = NO_ERROR;

	if (bl->bl_interface_type == BL_DCS)
		return ret;

	if(target_get_pmic() == PMIC_IS_PMI632) {
		ret = pwm_backlight_ctrl(enable);
	} else {
		dprintf(CRITICAL, "wled_backlight_ctrl(enable)\n");
		//add lizhongyu modify for niou PWM backlight
		//ret = wled_backlight_ctrl(enable);
		dprintf(CRITICAL, "target_backlight_ctrl()  PWM\n");
		ret = pwm_backlight_ctrl_niou(enable);
		//end
	}
	return ret;
}

ap\bootable\bootloader\lk\dev\pmic\pm8x41\pm_pwm.c
配合lcd头文件中的ek79030_1080p_video_backlight来使用

void pm_pwm_enable(bool enable)
{
	uint8_t reg;

	reg = enable << PM_PWM_ENABLE_CTL_SHIFT
		& PM_PWM_ENABLE_CTL_MASK;
	pm_pwm_reg_write(PM_PWM_ENABLE_CTL_REG_OFFSET, reg);
	//add mpp4 pwm
	if (enable){
		pm_pwm_reg_write(0xd0, 0xa5);
		pm_pwm_reg_write(0xe3, 0x02);
	} else {
		pm_pwm_reg_write(0xd0, 0x00);
		pm_pwm_reg_write(0xe3, 0x00);
	}
	//end add
}

4.2 内核部分移植
kernel\msm-4.9\arch\arm64\boot\dts\GM620S\dsi-panel-ek79030-1080p-video.dtsi

//qcom,mdss-dsi-bl-pmic-control-type = "bl_ctrl_wled";
qcom,mdss-dsi-bl-pmic-control-type = "bl_ctrl_pwm";
qcom,mdss-dsi-bl-min-level = <1>;
qcom,mdss-dsi-bl-max-level = <4095>;
qcom,mdss-dsi-bl-pmic-pwm-frequency = <100>;
qcom,mdss-dsi-bl-pmic-bank-select = <0>;
qcom,mdss-dsi-pwm-gpio = <&pm8953_mpps 4 0>;

ap\kernel\msm-4.9\arch\arm64\boot\dts\GM620S\pm8953.dtsi

pm8953_mpps: mpps {
			compatible = "qcom,spmi-mpp";
			reg = <0xa000 0x400>;

			interrupts = <0x0 0xa0 0 IRQ_TYPE_NONE>,
				<0x0 0xa1 0 IRQ_TYPE_NONE>,
				<0x0 0xa2 0 IRQ_TYPE_NONE>,
				<0x0 0xa3 0 IRQ_TYPE_NONE>;
			interrupt-names = "pm8953_mpp1", "pm8953_mpp2",
					"pm8953_mpp3", "pm8953_mpp4";

			gpio-controller;
			#gpio-cells = <2>;

			// add lizhongyu modify for niou PWM backlight --- start
			pinctrl-names = "default";
			pinctrl-0 = <&pm8953_default>;
			
			pm8953_default: pm8953_mpp4 {
				gpio {
					pins = "mpp4";
					function = "digital";
					output-high;
					bias-disable = <0>; //no pull
					qcom,dtest = <2>; //DTEST2
					power-source = <3>; //VPH_PWR
				};
			};
			
			/*case_therm {
				cas_therm_default: cas_therm_default {
					pins = "mpp4";
					function = "analog";
					input-enable;
					qcom,amux-route = <3>;
				};
			};*/ 
			//add lizhongyu modify for niou PWM backlight --- end

	pm8953_vadc: aaa@qq.com3100 {
			compatible = "qcom,qpnp-vadc";
			reg = <0x3100 0x100>;
			#address-cells = <1>;
			#size-cells = <0>;
			interrupts = <0x0 0x31 0x0 IRQ_TYPE_EDGE_RISING>;
			interrupt-names = "eoc-int-en-set";
			qcom,adc-bit-resolution = <15>;
			qcom,adc-vdd-reference = <1800>;
			qcom,vadc-poll-eoc;
			#thermal-sensor-cells = <1>;
			pinctrl-names = "default";
			pinctrl-0 = <&pa_therm1_default /*&cas_therm_default*/>; //chanage lizhongyu modify for niou PWM backlight

			aaa@qq.com5 {
				label = "vcoin";
				reg = <5>;
				qcom,decimation = <0>;
				qcom,pre-div-channel-scaling = <1>;
				qcom,calibration-type = "absolute";
				qcom,scale-function = <0>;
				qcom,hw-settle-time = <0>;
				qcom,fast-avg-setup = <0>;
			};

//add lizhongyu modify for niou PWM backlight --- start
     /*	pm8953_1: qcom,aaa@qq.com {
		compatible = "qcom,spmi-pmic";
		reg = <0x1 SPMI_USID>;
		#address-cells = <1>;
		#size-cells = <1>;

		pm8953_pwm: qcom,aaa@qq.com {
			status = "disabled";
			compatible = "qcom,pwm-lpg";
			reg = <0xbc00 0x100>;
			reg-names = "lpg-base";
			#pwm-cells = <2>;
		};
	};*/
	pm8953_1: qcom,aaa@qq.com1 {
		status = "ok";
		compatible = "qcom,spmi-pmic";
		reg = <0x1 SPMI_USID>;
		#address-cells = <1>;
		#size-cells = <1>;
		pm8953_pwm: aaa@qq.com {
			compatible = "qcom,qpnp-pwm";
			reg = <0xbc00 0x100>;
			reg-names = "qpnp-lpg-channel-base";
			qcom,channel-id = <0>;
			qcom,supported-sizes = <6>, <9>;
			#pwm-cells = <2>;
			qcom,dtest-line = <2>;
			qcom,dtest-output = <2>;
		};
	};
//end lizhongyu modify for niou PWM backlight --- end
};

内核中优化PWM输出的占空比：
kernel\msm-4.9\drivers\video\fbdev\msm\mdss_dsi_panel.c

static void mdss_dsi_panel_bklt_pwm(struct mdss_dsi_ctrl_pdata *ctrl, int level)
{
	int ret;
	u32 duty;
	u32 period_ns;

	if (ctrl->pwm_bl == NULL) {
		pr_err("%s: no PWM\n", __func__);
		return;
	}

	if (level == 0) {
		if (ctrl->pwm_enabled) {
			ret = pwm_config(ctrl->pwm_bl, 0,
					ctrl->pwm_period * NSEC_PER_USEC);
			if (ret)
				pr_err("%s: pwm_config() failed err=%d.\n",
						__func__, ret);
			pwm_disable(ctrl->pwm_bl);
		}
		ctrl->pwm_enabled = 0;
		return;
	}

	duty = level * ctrl->pwm_period; //pwm_period=100 pwm_gpio=1271 
	duty /= ctrl->bklt_max; //ctrl->bklt_max=4095

	pr_debug("%s: bklt_ctrl=%d pwm_period=%d pwm_gpio=%d pwm_lpg_chan=%d\n",
			__func__, ctrl->bklt_ctrl, ctrl->pwm_period,
				ctrl->pwm_pmic_gpio, ctrl->pwm_lpg_chan);

	pr_debug("%s: ndx=%d level=%d duty=%d\n", __func__,
					ctrl->ndx, level, duty);
	//添加优化代码
	//duty=40<--->100  //duty=40 level=1638 pwm_period=100 //duty=3 level=161 
	if((duty>=40)&&(duty<=60)){ //duty=40 <==>255 //duty=100 <==>10
	 	duty= duty-20;
	}
	//end add
	if (ctrl->pwm_period >= USEC_PER_SEC) {
		ret = pwm_config_us(ctrl->pwm_bl, duty, ctrl->pwm_period);
		if (ret) {
			pr_err("%s: pwm_config_us() failed err=%d.\n",
					__func__, ret);
			return;
		}
	} else {
		period_ns = ctrl->pwm_period * NSEC_PER_USEC;
		ret = pwm_config(ctrl->pwm_bl,
				level * period_ns / ctrl->bklt_max,
				period_ns);
		if (ret) {
			pr_err("%s: pwm_config() failed err=%d.\n",
					__func__, ret);
			return;
		}
	}
................................................................

4.3 修改BP测，将PMIC的MPP4这个管脚配置成PWM模式
修改BP测，将PMIC的MPP4这个管脚配置成PWM模式，否则系统启动时会报以下错误：

[   32.370588] qpnp_pwm_config: Failed to configure PWM mode
[   32.377116] mdss_dsi_panel_bklt_pwm: pwm_config() failed err=-19.
........................................................................
[   74.704024] qpnp_pwm_config: Failed to configure PWM mode
[   74.704035] mdss_dsi_panel_bklt_pwm: pwm_config() failed err=-19.
[   74.713036] spmi spmi-0: error: impermissible write to peripheral sid:1 addr:0xbc44
[   74.713049] qpnp_pwm_config: Failed to configure PWM mode
[   74.713056] mdss_dsi_panel_bklt_pwm: pwm_config() failed err=-19.
[   74.717835] spmi spmi-0: error: impermissible write to peripheral sid:1 addr:0xbc44
[   74.717848] qpnp_pwm_config: Failed to configure PWM mode
[   74.717855] mdss_dsi_panel_bklt_pwm: pwm_config() failed err=-19.

具体修改路径如下：
mdm/Tz.BF.4.0.5\trustzone_images\core\systemdrivers\pmic\config\msm8953_pm8950\src\pm_spmi_config.c
修改之后编译将devcfg.mbn和之前编译的内核和lk编译的img文件烧录系统即可。

参考：android7.1+msm8937背光控制

相关标签： 高通平台 背光

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