ohci-s3c2410.c

USB HOST DEVICE驱动程序


/* 
* OHCI HCD (Host Controller Driver) for USB
该程序主要完成s3c2410 USB 主机控制器的初始化工作,包括电源,时钟等
*/
//需要用到的头文件
#include <asm/hardware.h> 
#include <asm/mach-types.h> 
#include <asm/hardware/clock.h> 
#include <asm/arch/usb-control.h> 
//定义主机控制器的有效端口数
#define valid_port(idx) ((idx) == 1 || (idx) == 2) 

/* 主机控制器的时钟,在clock.h中有它的定义 */

static struct clk *clk; 

/* 预定义,s3c2410_hcd_oc   主机端口的过流保护函数*/

static void s3c2410_hcd_oc(struct s3c2410_hcd_info *info, int port_oc); 

/* 该函数返回总线上的当前的平台信息
    该函数的返回结构: (具体的定义在usb_control.h中)
    struct s3c2410_hcd_info{
            struct usb_hcd  *hcd;
            struct s3c2410_hcd_port port[2];
            void  (*power_control)(int port,int to);
            void  (*enable_oc)(struct s3c2410_hcd_info *,int on);
            void  (*report_oc)(struct s3c2410_hcd_info *,int ports);
    };


 */

struct s3c2410_hcd_info *to_s3c2410_info(struct usb_hcd *hcd) 
{ 
return hcd->self.controller->platform_data; 
} 
 /* s3c2410_start_hc  该函数启动主机控制器,主要是启动时钟,对打开对端口的过流保护
 */
static void s3c2410_start_hc(struct platform_device *dev, struct usb_hcd *hcd) 
{ 
struct s3c2410_hcd_info *info = dev->dev.platform_data; 

dev_dbg(&dev->dev, "s3c2410_start_hc:\n"); 
clk_enable(clk); 

if (info != NULL) { 
info->hcd = hcd; 
info->report_oc = s3c2410_hcd_oc; 

if (info->enable_oc != NULL) { 
(info->enable_oc)(info, 1); 
} 
} 
} 
 /* s3c2410_stop_hc  该函数停止主机控制器,关闭时钟
 */
static void s3c2410_stop_hc(struct platform_device *dev) 
{ 
struct s3c2410_hcd_info *info = dev->dev.platform_data; 

dev_dbg(&dev->dev, "s3c2410_stop_hc:\n"); 

if (info != NULL) { 
info->report_oc = NULL; 
info->hcd = NULL; 

if (info->enable_oc != NULL) { 
(info->enable_oc)(info, 0); 
} 
} 

clk_disable(clk); 
} 

/* ohci_s3c2410_hub_status_data  该函数是集线器的状态函数,
扫描集线器的两个下行端口,检测是否连接USB设备,若有返回1,无,返回0

*/ 

static int 
ohci_s3c2410_hub_status_data (struct usb_hcd *hcd, char *buf) 
{ 
struct s3c2410_hcd_info *info = to_s3c2410_info(hcd); 
struct s3c2410_hcd_port *port; 
int orig; 
int portno; 

orig = ohci_hub_status_data (hcd, buf); 

if (info == NULL) 
return orig; 

port = &info->port[0]; 

/*扫描两个端口*/

for (portno = 0; portno < 2; port++, portno++) { 
if (port->oc_changed == 1 && 
port->flags & S3C_HCDFLG_USED) { 
dev_dbg(hcd->self.controller, 
"oc change on port %d\n", portno); 

if (orig < 1) 
orig = 1; 

buf[0] |= 1<<(portno+1); 
} 
} 

return orig; 
} 

/* s3c2410_usb_set_power 该函数实现对端口的电源配置

*/ 

static void s3c2410_usb_set_power(struct s3c2410_hcd_info *info, 
int port, int to) 
{ 
if (info == NULL) 
return; 

if (info->power_control != NULL) { 
info->port[port-1].power = to; 
(info->power_control)(port, to); 
} 
} 

/* ohci_s3c2410_hub_control  该函数是集线器的控制函数
 处理一些对 集线器的控制请求
 具体参数:
typeReq 控制请求类别
 wValue 请求值
*/ 

static int ohci_s3c2410_hub_control (
struct usb_hcd *hcd, 
u16 typeReq, 
u16 wValue, 
u16 wIndex, 
char *buf, 
u16 wLength) 
{ 
struct s3c2410_hcd_info *info = to_s3c2410_info(hcd); 
struct usb_hub_descriptor *desc; 
int ret = -EINVAL; 
u32 *data = (u32 *)buf; 

dev_dbg(hcd->self.controller, 
"s3c2410_hub_control(%p,0x%04x,0x%04x,0x%04x,%p,%04x)\n", 
hcd, typeReq, wValue, wIndex, buf, wLength); 


if (info == NULL) { 
ret = ohci_hub_control(hcd, typeReq, wValue, 
wIndex, buf, wLength); 
goto out; 
} 

/* 检测HUB的请求类别,并且处理相关请求
*/

switch (typeReq) { 
/*集线器启用端口的请求  */
case SetPortFeature: 
if (wValue == USB_PORT_FEAT_POWER) { 
dev_dbg(hcd->self.controller, "SetPortFeat: POWER\n"); 
s3c2410_usb_set_power(info, wIndex, 1); 
goto out; 
} 
break; 
/* 消除端口的请求*/
case ClearPortFeature: 
/*具体的请求值*/
switch (wValue) { 
case USB_PORT_FEAT_C_OVER_CURRENT: 
dev_dbg(hcd->self.controller, 
"ClearPortFeature: C_OVER_CURRENT\n"); 

if (valid_port(wIndex)) { 
info->port[wIndex-1].oc_changed = 0; 
info->port[wIndex-1].oc_status = 0; 
} 

goto out; 

case USB_PORT_FEAT_OVER_CURRENT: 
dev_dbg(hcd->self.controller, 
"ClearPortFeature: OVER_CURRENT\n"); 

if (valid_port(wIndex)) { 
info->port[wIndex-1].oc_status = 0; 
} 

goto out; 

case USB_PORT_FEAT_POWER: 
dev_dbg(hcd->self.controller, 
"ClearPortFeature: POWER\n"); 

if (valid_port(wIndex)) { 
s3c2410_usb_set_power(info, wIndex, 0); 
return 0; 
} 
} 
break; 
} 

ret = ohci_hub_control(hcd, typeReq, wValue, wIndex, buf, wLength); 
if (ret) 
goto out; 

switch (typeReq) { 
/*获取集线器特定的描述符*/
case GetHubDescriptor: 

/* 更新集线器的描述符*/

desc = (struct usb_hub_descriptor *)buf; 

if (info->power_control == NULL) 
return ret; 

dev_dbg(hcd->self.controller, "wHubCharacteristics 0x%04x\n", 
desc->wHubCharacteristics); 

/* 更新集线器的配置,包括HUB电源和过流保护的配置
*/ 

desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_LPSM); 
desc->wHubCharacteristics |= cpu_to_le16(0x0001); 

if (info->enable_oc) { 
desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_OCPM); 
desc->wHubCharacteristics |= cpu_to_le16(0x0008|0x0001); 
} 

dev_dbg(hcd->self.controller, "wHubCharacteristics after 0x%04x\n", 
desc->wHubCharacteristics); 

return ret; 
/* 获取端口的状态 */
case GetPortStatus: 

dev_dbg(hcd->self.controller, "GetPortStatus(%d)\n", wIndex); 

if (valid_port(wIndex)) { 
if (info->port[wIndex-1].oc_changed) { 
*data |= cpu_to_le32(RH_PS_OCIC); 
} 

if (info->port[wIndex-1].oc_status) { 
*data |= cpu_to_le32(RH_PS_POCI); 
} 
} 
} 

out: 
return ret; 
} 

/* s3c2410_hcd_oc  该函数是主机控制器对端口的过流保护

*/ 

static void s3c2410_hcd_oc(struct s3c2410_hcd_info *info, int port_oc) 
{ 
struct s3c2410_hcd_port *port; 
struct usb_hcd *hcd; 
unsigned long flags; 
int portno; 

if (info == NULL) 
return; 

port = &info->port[0]; 
hcd = info->hcd; 

local_irq_save(flags); 

for (portno = 0; portno < 2; port++, portno++) { 
if (port_oc & (1<<portno) && 
port->flags & S3C_HCDFLG_USED) { 
port->oc_status = 1; 
port->oc_changed = 1; 

/* 停止该端口的供电 */
s3c2410_usb_set_power(info, portno+1, 0); 
} 
} 

local_irq_restore(flags); 
} 

/*  usb_hcd_s3c2410_remove  主机控制器的卸载
停止主机控制器,释放内存资源

* 
*/ 

void usb_hcd_s3c2410_remove (struct usb_hcd *hcd, struct platform_device *dev) 
{ 
usb_remove_hcd(hcd); 
s3c2410_stop_hc(dev); 
iounmap(hcd->regs);  //解除与内存映射的关系函数
release_mem_region(hcd->rsrc_start, hcd->rsrc_len); 
usb_put_hcd(hcd); 
} 

/**  usb_hcd_s3c2410_probe    USB 主机控制器的探测函数.
  主要实现对主机控制器进行分配资源,并启动主机控制器等
*/ 
int usb_hcd_s3c2410_probe (const struct hc_driver *driver, 
struct platform_device *dev) 
{ 
struct usb_hcd *hcd = NULL; 
int retval; 
/** 给端口进行供电*/
s3c2410_usb_set_power(dev->dev.platform_data, 0, 1); 
s3c2410_usb_set_power(dev->dev.platform_data, 1, 1); 
/** usb_create_hcd() 函数初始化主机控制器*/
hcd = usb_create_hcd(driver, &dev->dev, "s3c24xx"); 
if (hcd == NULL) 
return -ENOMEM; //系统错误,没有相应的内存空间
 /*主机控制器的资源节点*/
hcd->rsrc_start = dev->resource[0].start; 
hcd->rsrc_len = dev->resource[0].end - dev->resource[0].start + 1; 
 /*请求分配内存资源*/
if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) { 
dev_err(&dev->dev, "request_mem_region failed"); 
retval = -EBUSY;   //系统错误,表示要分配的内存资源已经被占用
goto err0; 
} 

clk = clk_get(NULL, "usb-host"); 
if (IS_ERR(clk)) { 
dev_err(&dev->dev, "cannot get usb-host clock\n"); 
retval = -ENOENT; 
goto err1; 
} 
/*启动始终,并启动主机控制器*/
clk_use(clk); 
s3c2410_start_hc(dev, hcd); 
/*ioremap()作用是将物理地址映射成相应的虚拟地址*/
hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len); 
if (!hcd->regs) { 
dev_err(&dev->dev, "ioremap failed\n"); 
retval = -ENOMEM; 
goto err2; 
} 

ohci_hcd_init(hcd_to_ohci(hcd)); 

retval = usb_add_hcd(hcd, dev->resource[1].start, SA_INTERRUPT); 
if (retval != 0) 
goto err2; 

return 0; 

err2: 
s3c2410_stop_hc(dev); 
iounmap(hcd->regs); 
clk_unuse(clk); 
clk_put(clk); 

err1: 
release_mem_region(hcd->rsrc_start, hcd->rsrc_len); 

err0: 
usb_put_hcd(hcd); 
return retval; 
} 
/* ohci_s3c2410_start 开放式主机控制器接口的启动函数
  调用上层的 ohci_run()函数来实现该功能
*/

static int 
ohci_s3c2410_start (struct usb_hcd *hcd) 
{ 
struct ohci_hcd *ohci = hcd_to_ohci (hcd); 
int ret; 

if ((ret = ohci_init(ohci)) < 0) 
return ret; 

if ((ret = ohci_run (ohci)) < 0) { 
err ("can't start %s", hcd->self.bus_name); 
ohci_stop (hcd); 
return ret; 
} 

return 0; 
} 
/*节点操作函数的实例
定义了2410 USB主机控制器的具体操作函数实例
*/

static const struct hc_driver ohci_s3c2410_hc_driver = { 
.description = hcd_name, 
.product_desc = "S3C24XX OHCI", 
.hcd_priv_size = sizeof(struct ohci_hcd), 


.irq = ohci_irq, 
.flags = HCD_USB11 | HCD_MEMORY, 

.start = ohci_s3c2410_start, 
.stop = ohci_stop, 

/* 
* 管理I/O请求＆相关的设备资源
*/ 
.urb_enqueue = ohci_urb_enqueue, //提交URB的具体处理函数
.urb_dequeue = ohci_urb_dequeue, 
.endpoint_disable = ohci_endpoint_disable, 

/* 
*调度支持，获取当前总线帧号
*/ 
.get_frame_number = ohci_get_frame, 

/* 
* 根集线器的控制实例
*/ 
.hub_status_data = ohci_s3c2410_hub_status_data, 
.hub_control = ohci_s3c2410_hub_control, 

#if defined(CONFIG_USB_SUSPEND) && 0 
.hub_suspend = ohci_hub_suspend, 
.hub_resume = ohci_hub_resume, 
#endif 
}; 

/*ohci_hcd_s3c2410_drv_probe  主机控制器驱动的探测函数   */

static int ohci_hcd_s3c2410_drv_probe(struct device *dev) 
{ 
struct platform_device *pdev = to_platform_device(dev); 
return usb_hcd_s3c2410_probe(&ohci_s3c2410_hc_driver, pdev); 
} 
/*ohci_hcd_s3c2410_drv_remove  主机控制器驱动的卸载函数   */
static int ohci_hcd_s3c2410_drv_remove(struct device *dev) 
{ 
struct platform_device *pdev = to_platform_device(dev); 
struct usb_hcd *hcd = dev_get_drvdata(dev); 

usb_hcd_s3c2410_remove(hcd, pdev); 
return 0; 
} 
/*
*s3c2410 主机控制驱动的结构实例
***/
static struct device_driver ohci_hcd_s3c2410_driver = { 
.name = "s3c2410-ohci",   //驱动名称
.bus = &platform_bus_type,  //总线类型
.probe = ohci_hcd_s3c2410_drv_probe,  //驱动的探测
.remove = ohci_hcd_s3c2410_drv_remove,  //驱动的卸载

}; 
/*s3c2410主机控制器的初始，系统调用，注册主机设备  */
static int __init ohci_hcd_s3c2410_init (void) 
{ 
return driver_register(&ohci_hcd_s3c2410_driver); 
} 
 /* s3c2410主机控制器的注销，从Linux内核中注销驱动程序 */
static void __exit ohci_hcd_s3c2410_cleanup (void) 
{ 
driver_unregister(&ohci_hcd_s3c2410_driver); 
} 
/*  初始＆卸载 s3c2410主机控制模块   */
module_init (ohci_hcd_s3c2410_init); 
module_exit (ohci_hcd_s3c2410_cleanup);