sdhci子系统

太过爱你忘了你带给我的痛 2023-10-08 10:09 8阅读 0赞

原文网址：[sdhci子系统\_IT利刃出鞘的博客-CSDN博客][sdhci_IT_-CSDN]

## 读写流程 ##

见：[mmc读写流程][mmc]  
最终调用到：sdhci\_request //drivers/mmc/host/sdhci.c

原因：  
sdhci\_xxx\_probe //drivers/mmc/host/sdhci-xxx.c  
sdhci\_alloc\_host  
host->mmc\_host\_ops = sdhci\_ops;  
mmc->ops = &host->mmc\_host\_ops;

//sdhci\_ops.request = sdhci\_request

## probe流程 ##

sdhci\_xxx\_probe(struct platform\_device \*pdev) //mmc/host/sdhci-xxx.c  
struct sdhci\_host \*host;  
host = sdhci\_pltfm\_init(pdev, &sdhci\_hik\_pdata, sizeof(struct sdhci\_hik\_priv)); //mmc/host/sdhci-pltfm.c  
//第1个参数名为：pdev,第2个参数名为：pdata

struct sdhci\_host \*host;  
iomem = platform\_get\_resource(pdev, IORESOURCE\_MEM, 0);  
ioaddr = devm\_ioremap\_resource(&pdev->dev, iomem);  
host->ioaddr = ioaddr;  
  
irq = platform\_get\_irq(pdev, 0);  
host->irq = irq;  
  
host = sdhci\_alloc\_host(&pdev->dev, sizeof(struct sdhci\_pltfm\_host) + priv\_size); //mmc/host/sdhci.c  
//最后一个参数名为priv\_size  
struct mmc\_host \*mmc;  
struct sdhci\_host \*host;  
mmc = mmc\_alloc\_host(sizeof(struct sdhci\_host) + priv\_size, dev);  
**host->mmc = mmc;**  
**host->mmc\_host\_ops = sdhci\_ops**; //sdhci\_ops在mmc/host/sdhci.c中定义  
**mmc->ops = &host->mmc\_host\_ops**;  
host->flags = **SDHCI\_SIGNALING\_330**;  
**host->ops = pdata->ops**  
host->quirks = pdata->quirks;  
host->quirks2 = pdata->quirks2;  
**pdev->dev->driver\_data = host**  
  
mmc\_of\_parse(host->mmc); //mmc/core/mmc.c  
//参数名为host  
通过设备树设置host成员：f\_max,caps,caps2  
  
sdhci\_add\_host(host); //mmc/host/sdhci.c  
**sdh**ci\_setup\_host(host); //mmc/host/sdhci.c  
sdhci\_read\_caps(host); //mmc/host/sdhci.h  
\_\_sdhci\_read\_caps(host, NULL, NULL, NULL); //mmc/host/sdhci.c  
sdhci\_do\_reset(host, SDHCI\_RESET\_ALL); //mmc/host/sdhci.c  
host->ops->reset(host, mask);  
host->version = (sdhci\_readw(host, SDHCI\_HOST\_VERSION) & SDHCI\_SPEC\_VER\_MASK) >>  
SDHCI\_SPEC\_VER\_SHIFT;  
如果 (host->quirks & **SDHCI\_QUIRK\_MISSING\_CAPS**) return  
否则 host->caps = caps ? \*caps : sdhci\_readl(host, SDHCI\_CAPABILITIES);  
  
如果 (host->version < SDHCI\_SPEC\_300) return;  
否则 host->caps1 = caps1 ? \*caps1 : sdhci\_readl(host, SDHCI\_CAPABILITIES\_1);  
  
**根据host的quirk,quirk2,caps,version设置host的caps,flags,mmc等成员**  
如果使用DMA，则调用dma\_alloc\_coherent分配一致性内存  
  
**\_\_sd**hci\_add\_host(host) //mmc/host/sdhci.c  
tasklet\_init(&host->finish\_tasklet, sdhci\_tasklet\_finish, (unsigned long)host);  
setup\_timer(&host->timer, sdhci\_timeout\_timer, (unsigned long)host);  
setup\_timer(&host->data\_timer, sdhci\_timeout\_data\_timer, (unsigned long)host);  
init\_waitqueue\_head(&host->buf\_ready\_int);  
  
sdhci\_init(host, 0); //mmc/host/sdhci.c  
sdhci\_do\_reset(host, SDHCI\_RESET\_ALL); //mmc/host/sdhci.c  
//写中断使能寄存器、写信号使能寄存器  
sdhci\_writel(host, host->ier, SDHCI\_INT\_ENABLE);  
sdhci\_writel(host, host->ier, SDHCI\_SIGNAL\_ENABLE);  
  
ret = request\_threaded\_irq(host->irq, sdhci\_irq, sdhci\_thread\_irq, IRQF\_SHARED, mmc\_hostname(mmc), host);  
mmc\_add\_host(mmc); //mmc/core/host.c  
pr\_info("%s: SDHCI controller on %s \[%s\] using %s\\n",  
mmc\_hostname(mmc), host->hw\_name, dev\_name(mmc\_dev(mmc)),  
(host->flags & **SDHCI\_USE\_ADMA**) ?  
(host->flags & SDHCI\_USE\_64\_BIT\_DMA) ? "ADMA 64-bit" : "ADMA" :  
(host->flags & SDHCI\_USE\_SDMA) ? "DMA" : "PIO");  
//打印示例：mmc2: SDHCI controller on 4030000.eMMC \[4030000.eMMC\] using ADMA 64-bit in legacy mode  
  
sdhci\_enable\_card\_detection(host); //mmc/host/sdhci.c  
if ((host->quirks & SDHCI\_QUIRK\_BROKEN\_CARD\_DETECTION) || !mmc\_card\_is\_removable(host->mmc))  
return;  
设置host->ier相关位  
sdhci\_writel(host, host->ier, SDHCI\_INT\_ENABLE);  
sdhci\_writel(host, host->ier, SDHCI\_SIGNAL\_ENABLE);

## 中断处理流程 ##

注册代码：mmc/host/sdhci.c  
ret = request\_threaded\_irq(host->irq, sdhci\_irq, sdhci\_thread\_irq, IRQF\_SHARED, mmc\_hostname(mmc), host);

shhci\_irq //mmc/host/sdhci.c

如果是命令中断  
设置中断返回值  
将host->finish\_tasklet加入调度（sdhci\_finish\_mrq(host, host->cmd->mrq))  
读取并设置响应数据（如果命令是需要响应的）  
如果是数据中断  
设置中断返回值  
将host->finish\_tasklet加入调度（sdhci\_finish\_mrq(host, data\_cmd->mrq);)  
处理数据

//若sdhci\_irq返回IRQ\_WAKE\_THREAD，则调用sdhci\_thread\_irq  
sdhci\_thread\_irq //mmc/host/sdhci.c //sd卡插入中断、拔出中断、sd卡中断会返回IRQ\_WAKE\_THREAD  
如果是sd卡插入或拔出中断  
struct mmc\_host \*mmc = host->mmc;  
mmc->ops->card\_event(mmc); //即sdhci\_ops.card\_event （即sdhci\_card\_event）  
sdhci\_card\_event //mmc/host/sdhci.c  
struct sdhci\_host \*host = mmc\_priv(mmc);  
如果host->ops提供card\_event则调用  
present = mmc->ops->get\_cd(mmc);  
...不重要代码  
mmc\_detect\_change(mmc, msecs\_to\_jiffies(200)); //mmc/core/core.c  
\_mmc\_detect\_change(host, delay, true); //mmc/core/core.c  
mmc\_schedule\_delayed\_work(&host->detect, delay);  
调度host->decect对应的函数 //INIT\_DELAYED\_WORK(&host->detect, mmc\_rescan);  
//mmc/core/host.c=> mmc\_alloc\_host  
mmc\_rescan //mmc/core/core.c

[sdhci_IT_-CSDN]: https://knife.blog.csdn.net/article/details/103306485
[mmc]: https://blog.csdn.net/feiying0canglang/article/details/101778289#%E8%AF%BB%E5%86%99%E6%B5%81%E7%A8%8B