高通平台读取USB ID

左手的ㄟ右手 2022-10-28 11:29 360阅读 0赞

**参考文件：**  
kernel/drivers/usb/phy/phy-msm-usb.c  
kernel/msm-3.18/drivers/usb/phy/phy-msm-usb.c

+//begin:stone modify for usb id
    +static bool usb_id_flag = 1;
    +bool get_usb_id(void)
    +{
        
    +	return usb_id_flag;
    +}
    +EXPORT_SYMBOL(get_usb_id);
    +//end:stone modify for usb id

在msm\_id\_status\_w函数中添加即可：

static void msm_id_status_w(struct work_struct *w)
    {
        
    	struct msm_otg *motg = container_of(w, struct msm_otg,
    						id_status_work.work);
    	int work = 0;
    	int id_state = 0;
    
    	dev_dbg(motg->phy.dev, "ID status_w\n");
    
    	if (motg->pdata->pmic_id_irq)
    		id_state = msm_otg_read_pmic_id_state(motg);
    	else if (motg->ext_id_irq)
    		id_state = gpio_get_value(motg->pdata->usb_id_gpio);
    		
    	/******************************************************/
    	else if (motg->phy_irq)
    		id_state = msm_otg_read_phy_id_state(motg);
    		//usb_otg: usb@78d9000 {中定义了：
    		//interrupt-names = "core_irq", "async_irq","phy_irq";
    		//motg->phy_irq = platform_get_irq_byname(pdev, "phy_irq");
    		//所以phy_irq不为空，走到这里
    	/******************************************************/
    		
    	if (id_state) {
        
    		if (!test_and_set_bit(ID, &motg->inputs)) {
        
    			pr_debug("ID set\n");
    			msm_otg_dbg_log_event(&motg->phy, "ID SET",
    					motg->inputs, motg->phy.state);
    			work = 1;
    		}
    	} else {
        
    		if (test_and_clear_bit(ID, &motg->inputs)) {
        
    			pr_debug("ID clear\n");
    			msm_otg_dbg_log_event(&motg->phy, "ID CLEAR",
    					motg->inputs, motg->phy.state);
    			set_bit(A_BUS_REQ, &motg->inputs);
    			work = 1;
    		}
    	}
    
    	+//begin:stone modify for usb id
    	+usb_id_flag = !!id_state;
    	+printk(KERN_ERR "usb_id_flag=%d\n",usb_id_flag);
    	+//end:stone modify for usb id
    
    	if (work && (motg->phy.state != OTG_STATE_UNDEFINED)) {
        
    		msm_otg_dbg_log_event(&motg->phy,
    				"CHECK ID EVENT DURING SUSPEND",
    				atomic_read(&motg->pm_suspended),
    				motg->sm_work_pending);
    		if (atomic_read(&motg->pm_suspended)) {
        
    			motg->sm_work_pending = true;
    		} else if (!motg->sm_work_pending) {
        
    			/* process event only if previous one is not pending */
    			queue_work(motg->otg_wq, &motg->sm_work);
    		}
    	}
    
    }

真正读取ID的函数是msm\_otg\_read\_phy\_id\_state：

static bool msm_otg_read_phy_id_state(struct msm_otg *motg)
    {
        
    	u8 val;
    
    	/*
    	 * clear the pending/outstanding interrupts and
    	 * read the ID status from the SRC_STATUS register.
    	 */
    	writeb_relaxed(USB_PHY_ID_MASK, USB2_PHY_USB_PHY_INTERRUPT_CLEAR1);
    
    	writeb_relaxed(0x1, USB2_PHY_USB_PHY_IRQ_CMD);
    	/*
    	 * Databook says 200 usec delay is required for
    	 * clearing the interrupts.
    	 */
    	udelay(200);
    	writeb_relaxed(0x0, USB2_PHY_USB_PHY_IRQ_CMD);
    
    	val = readb_relaxed(USB2_PHY_USB_PHY_INTERRUPT_SRC_STATUS);
    	if (val & USB_PHY_IDDIG_1_0)
    		return false; /* ID is grounded */
    	else
    		return true;
    }

USB2\_PHY\_USB\_PHY\_INTERRUPT\_SRC\_STATUS的定义：

#define USB2_PHY_USB_PHY_INTERRUPT_SRC_STATUS (MSM_USB_PHY_CSR_BASE + 0x05C)

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L2Nvcm5lcnN0b25lMQ_size_16_color_FFFFFF_t_70]  
IDDIG\_1\_0表示中断状态由1变为0。

查看设备树节点：

usb_otg: usb@78d9000 {
        
    		compatible = "qcom,hsusb-otg";
    		reg = <0x78d9000 0x400>, <0x6c000 0x200>;
    		reg-names = "core", "phy_csr";
    
    		interrupts = <0 134 0>,<0 140 0>,<0 136 0>;
    		interrupt-names = "core_irq", "async_irq","phy_irq";
                 // qcom,usbid-gpio
    		hsusb_vdd_dig-supply = <&pm8909_l2>;
    		HSUSB_1p8-supply = <&pm8909_l7>;
    		HSUSB_3p3-supply = <&pm8909_l13>;
    		qcom,vdd-voltage-level = <0 1200000 1200000>;
    
    		qcom,hsusb-otg-phy-init-seq = <0x73 0x80 0xffffffff>;
    		qcom,hsusb-otg-phy-type = <3>; /* SNPS Femto PHY */
    		//qcom,hsusb-otg-mode = <1>; /* DEVICE only */
    		//qcom,hsusb-otg-otg-control = <2>; /* PMIC */
    		qcom,hsusb-otg-mode = <3>; /* OTG */
    		qcom,hsusb-otg-otg-control =<2>;// <2>;
    		qcom,vbus-en-gpio=<&msm_gpio 58 0>;
    		//qcom,usbid-gpio=<&msm_gpio 31 0>;    //这个属性是没有定义的
    			
    		qcom,dp-manual-pullup;
    		qcom,hsusb-otg-disable-reset;
    		qcom,phy-dvdd-always-on;
    		qcom,hsusb-otg-mpm-dpsehv-int = <49>;
    		qcom,hsusb-otg-mpm-dmsehv-int = <58>;
    
    		qcom,msm-bus,name = "usb2";
    		qcom,msm-bus,num-cases = <3>;
    		qcom,msm-bus,num-paths = <1>;
    		qcom,msm-bus,vectors-KBps =
    				<87 512 0 0>,
    				<87 512 80000 0>,
    				<87 512 6000  6000>;
    		clocks = <&clock_gcc clk_gcc_usb_hs_ahb_clk>,
    			 <&clock_gcc clk_gcc_usb_hs_system_clk>,
    			 <&clock_gcc clk_gcc_usb2a_phy_sleep_clk>,
    			 <&clock_rpm clk_bimc_usb_a_clk>,
    			 <&clock_rpm clk_snoc_usb_a_clk>,
    			 <&clock_rpm clk_pcnoc_usb_a_clk>,
    			 <&clock_gcc clk_gcc_qusb2_phy_clk>,
    			 <&clock_gcc clk_gcc_usb2_hs_phy_only_clk>,
    			 <&clock_gcc clk_gcc_usb_hs_phy_cfg_ahb_clk>,
    			 <&clock_rpm clk_xo_otg_clk>;
    		clock-names = "iface_clk", "core_clk", "sleep_clk",
    				"bimc_clk", "snoc_clk", "pcnoc_clk",
    				"phy_reset_clk", "phy_por_clk", "phy_csr_clk",
    				"xo";
    		qcom,bus-clk-rate = <400000000 200000000 100000000>;
    	};

**流程：**  
msm\_otg\_probe中去注册中断函数的：

motg->phy_irq = platform_get_irq_byname(pdev, "phy_irq");
    	if (motg->phy_irq < 0) {
        
    		dev_dbg(&pdev->dev, "phy_irq is not present\n");
    		motg->phy_irq = 0;
    	} else {
        
    
    		/* clear all interrupts before enabling the IRQ */
    		writeb_relaxed(0xFF, USB2_PHY_USB_PHY_INTERRUPT_CLEAR0);
    		writeb_relaxed(0xFF, USB2_PHY_USB_PHY_INTERRUPT_CLEAR1);
    
    		writeb_relaxed(0x1, USB2_PHY_USB_PHY_IRQ_CMD);
    		/*
    		 * Databook says 200 usec delay is required for
    		 * clearing the interrupts.
    		 */
    		udelay(200);
    		writeb_relaxed(0x0, USB2_PHY_USB_PHY_IRQ_CMD);
    
    		ret = request_irq(motg->phy_irq, msm_otg_phy_irq_handler,
    				IRQF_TRIGGER_RISING, "msm_otg_phy_irq", motg);
    		if (ret < 0) {
        
    			dev_err(&pdev->dev, "phy_irq request fail %d\n", ret);
    			goto free_irq;
    		}
    	}

因为phy\_irq在设备树节点中定义了，所以走到else，这里注册中断函数msm\_otg\_phy\_irq\_handler。在中断函数里读取ID状态：

static irqreturn_t msm_otg_phy_irq_handler(int irq, void *data)
    {
        
    	struct msm_otg *motg = data;
    
    	msm_otg_dbg_log_event(&motg->phy, "PHY ID IRQ",
    			atomic_read(&motg->in_lpm), motg->phy.state);
    	if (atomic_read(&motg->in_lpm)) {
        
    		pr_debug("PHY ID IRQ in LPM\n");
    		motg->phy_irq_pending = true;
    		if (!atomic_read(&motg->pm_suspended))
    			pm_request_resume(motg->phy.dev);
    	} else {
        
    		pr_debug("PHY ID IRQ outside LPM\n");
    		msm_id_status_w(&motg->id_status_work.work);
    	}
    
    	return IRQ_HANDLED;
    }

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