04_Linux驱动_05_pinctrl子系统

以下代码都在pinctrl相关的驱动函数和设备树中

pinctrl-rockchip.c驱动，对应的是那个（那些）设备树呢？

答案：通过.compatible = "rockchip,rk3568-pinctrl"连接到rk3568.dtsi根节点下的pinctrl节点

一，pinctrl_desc结构体

/*用于描述 Pin controller
*/
struct pinctrl_desc {const char *name;                    //1，名字const struct pinctrl_pin_desc *pins; //2，一个引脚unsigned int npins;                  //3，一共有多少引脚const struct pinctrl_ops *pctlops;   //4，xxx操作集合const struct pinmux_ops *pmxops;     //5，xxx操作集合const struct pinconf_ops *confops;   //6，xxx操作集合struct module *owner;                //7，模块的拥有者
#ifdef CONFIG_GENERIC_PINCONFunsigned int num_custom_params;      //自定义相关const struct pinconf_generic_params *custom_params;const struct pin_config_item *custom_conf_items;
#endif
};

构建完 pinctrl结构体之后，会调用pinctrl_register函数注册一个pinctrl控制器，得到一个pinctrl_dev。

1.1pinctrl_desc结构体在probe中的使用

不同的芯片厂，的pinctrl的驱动不一样，我的被打包到了rockchip_pinctrl结构体之中了！！！


struct rockchip_pinctrl {struct regmap			*regmap_base;int				reg_size;struct regmap			*regmap_pull;struct regmap			*regmap_pmu;struct device			*dev;struct rockchip_pin_ctrl	*ctrl;struct pinctrl_desc		pctl;            //在这里struct pinctrl_dev		*pctl_dev;struct rockchip_pin_group	*groups;unsigned int			ngroups;struct rockchip_pmx_func	*functions;unsigned int			nfunctions;
};

1.2用rockchip_pinctrl_register函数进行注册。

ret = rockchip_pinctrl_register(pdev, info);
if (ret)return ret;--->>进入rockchip_pinctrl_register函数
{struct pinctrl_desc *ctrldesc = &info->pctl;struct pinctrl_pin_desc *pindesc, *pdesc;struct rockchip_pin_bank *pin_bank;int pin, bank, ret;int k;ctrldesc->name = "rockchip-pinctrl";    //驱动名字和compatible配对ctrldesc->owner = THIS_MODULE;          ctrldesc->pctlops = &rockchip_pctrl_ops;  //三个操作集合ctrldesc->pmxops = &rockchip_pmx_ops;     //ctrldesc->confops = &rockchip_pinconf_ops;////给管脚申请内存空间pindesc = devm_kcalloc(&pdev->dev,info->ctrl->nr_pins, sizeof(*pindesc),GFP_KERNEL);if (!pindesc)return -ENOMEM;ctrldesc->pins = pindesc;ctrldesc->npins = info->ctrl->nr_pins;//给管脚 编号 命名pdesc = pindesc;for (bank = 0, k = 0; bank < info->ctrl->nr_banks; bank++) {pin_bank = &info->ctrl->pin_banks[bank];for (pin = 0; pin < pin_bank->nr_pins; pin++, k++) {pdesc->number = k;pdesc->name = kasprintf(GFP_KERNEL, "%s-%d",pin_bank->name, pin);pdesc++;}}//在devm_pinctrl_register中调用pinctrl_register函数进行注册ret = rockchip_pinctrl_parse_dt(pdev, info);if (ret)return ret;info->pctl_dev = devm_pinctrl_register(&pdev->dev, ctrldesc, info);if (IS_ERR(info->pctl_dev)) {dev_err(&pdev->dev, "could not register pinctrl driver\n");return PTR_ERR(info->pctl_dev);}}

二，pinctrl 子系统函数操作集

2.1 groups和function

groups（引脚组）：

引脚组是一组具有相似功能、约束条件或共同工作的引脚的集合。

function（功能）：

定义了芯片上具有外设功能的功能。每个功能节点对应于一个或多个 IO 组（group）的配置信息。这些功能可以是串口、SPI、I2C 等外设功能。

在.dtsi文件中：

    can0 {                              //这是一个function/omit-if-no-ref/                //这是一组groupscan0m0_pins: can0m0-pins {rockchip,pins =/* can0_rxm0 */<0 RK_PB4 2 &pcfg_pull_none>,/* can0_txm0 */<0 RK_PB3 2 &pcfg_pull_none>;};/omit-if-no-ref/                 //这是一另组groupscan0m1_pins: can0m1-pins {rockchip,pins =/* can0_rxm1 */<2 RK_PA2 4 &pcfg_pull_none>,/* can0_txm1 */<2 RK_PA1 4 &pcfg_pull_none>;};};can1 {                               //这是一另个function                  /omit-if-no-ref/can1m0_pins: can1m0-pins {rockchip,pins =/* can1_rxm0 */<1 RK_PA0 3 &pcfg_pull_none>,/* can1_txm0 */<1 RK_PA1 3 &pcfg_pull_none>;};/omit-if-no-ref/can1m1_pins: can1m1-pins {rockchip,pins =/* can1_rxm1 */<4 RK_PC2 3 &pcfg_pull_none>,/* can1_txm1 */<4 RK_PC3 3 &pcfg_pull_none>;};};

可已这么说：can0和can1对应2个function，为CAN0控制器和CAN1控制器，而每个控制器中又有2给不同的groups引脚组

2.2pinctrl_ops结构体：

里面都是函数。

struct pinctrl_ops {//获取设备树中的groups用了多少个int (*get_groups_count) (struct pinctrl_dev *pctldev);//获取指定groups的名字const char *(*get_group_name) (struct pinctrl_dev *pctldev,unsigned selector);//获取指定groups的管脚int (*get_group_pins) (struct pinctrl_dev *pctldev,unsigned selector,const unsigned **pins,unsigned *num_pins);//调试用void (*pin_dbg_show) (struct pinctrl_dev *pctldev, struct seq_file *s,unsigned offset);//节点转化为mapint (*dt_node_to_map) (struct pinctrl_dev *pctldev,struct device_node *np_config,struct pinctrl_map **map, unsigned *num_maps);//dt_node_to_map的反操作void (*dt_free_map) (struct pinctrl_dev *pctldev,struct pinctrl_map *map, unsigned num_maps);
};

2.3pinmux_ops结构体：

/*  pinctrl_dev：代表着一个 pin controller*/
struct pinmux_ops {//1，申请引脚int (*request) (struct pinctrl_dev *pctldev, unsigned offset);//2，释放引脚int (*free) (struct pinctrl_dev *pctldev, unsigned offset);//3，获取 pin controller 中 function 的数量int (*get_functions_count) (struct pinctrl_dev *pctldev);//4，获取指定 function 的名字const char *(*get_function_name) (struct pinctrl_dev *pctldev,unsigned selector);//5，获取指定 function 的 groupsint (*get_function_groups) (struct pinctrl_dev *pctldev,unsigned selector,const char * const **groups,unsigned *num_groups);//6，设定引脚的 复用功能 （GPIO/I2C/SPI...)int (*set_mux) (struct pinctrl_dev *pctldev, unsigned func_selector,unsigned group_selector);//7，申请并使能 GPIOint (*gpio_request_enable) (struct pinctrl_dev *pctldev,struct pinctrl_gpio_range *range,unsigned offset);//8，禁止并释放 GPIOvoid (*gpio_disable_free) (struct pinctrl_dev *pctldev,struct pinctrl_gpio_range *range,unsigned offset);//9，设置GPIO的方向int (*gpio_set_direction) (struct pinctrl_dev *pctldev,struct pinctrl_gpio_range *range,unsigned offset,bool input);//不允许同时在同一个引脚上使用 GPIO 和 其他功能 （在同一时间，只能用一个功能）bool strict;
};

2.4pinconf_ops结构体：

struct pinconf_ops {
#ifdef CONFIG_GENERIC_PINCONFbool is_generic;
#endif//1，获取某个引脚的配置int (*pin_config_get) (struct pinctrl_dev *pctldev,unsigned pin,unsigned long *config);//2，设置某个引脚的配置int (*pin_config_set) (struct pinctrl_dev *pctldev,unsigned pin,unsigned long *configs,unsigned num_configs);//3，设置某个组的引脚配置int (*pin_config_group_get) (struct pinctrl_dev *pctldev,unsigned selector,unsigned long *config);//4，获取某个组的引脚配置int (*pin_config_group_set) (struct pinctrl_dev *pctldev,unsigned selector,unsigned long *configs,unsigned num_configs);//6，解析和修改调试信息int (*pin_config_dbg_parse_modify) (struct pinctrl_dev *pctldev,const char *arg,unsigned long *config);//789，调试使用void (*pin_config_dbg_show) (struct pinctrl_dev *pctldev,struct seq_file *s,unsigned offset);void (*pin_config_group_dbg_show) (struct pinctrl_dev *pctldev,struct seq_file *s,unsigned selector);void (*pin_config_config_dbg_show) (struct pinctrl_dev *pctldev,struct seq_file *s,unsigned long config);
};

2.5rockchip_pinctrl 进一步分析

在1.1中我看到了struct pinctrl_desc，在pinctrl_desc结构体里有：

struct rockchip_pin_group *groups;   //瑞芯微芯片引脚组指针
unsigned int ngroups;                //引脚组数量
struct rockchip_pmx_func *functions; //瑞芯微芯片引脚功能指针
unsigned int nfunctions;             //引脚功能数量

这四个变量被在pinctrl的probe函数中-->rockchip_pinctrl_register函数中的rockchip_pinctrl_parse_dt函数处理：


static int rockchip_pinctrl_register(struct platform_device *pdev,struct rockchip_pinctrl *info)
{struct pinctrl_desc *ctrldesc = &info->pctl;struct pinctrl_pin_desc *pindesc, *pdesc;struct rockchip_pin_bank *pin_bank;int pin, bank, ret;int k;ctrldesc->name = "rockchip-pinctrl";ctrldesc->owner = THIS_MODULE;ctrldesc->pctlops = &rockchip_pctrl_ops;    //瑞芯微封装的操作集1ctrldesc->pmxops = &rockchip_pmx_ops;       //瑞芯微封装的操作集2ctrldesc->confops = &rockchip_pinconf_ops;  //瑞芯微封装的操作集3pindesc = devm_kcalloc(&pdev->dev,info->ctrl->nr_pins, sizeof(*pindesc),GFP_KERNEL);if (!pindesc)return -ENOMEM;ctrldesc->pins = pindesc;ctrldesc->npins = info->ctrl->nr_pins;pdesc = pindesc;for (bank = 0, k = 0; bank < info->ctrl->nr_banks; bank++) {pin_bank = &info->ctrl->pin_banks[bank];for (pin = 0; pin < pin_bank->nr_pins; pin++, k++) {pdesc->number = k;pdesc->name = kasprintf(GFP_KERNEL, "%s-%d",pin_bank->name, pin);pdesc++;}}//rockchip_pinctrl_parse_dt在这个函数里处理了上面四个变量ret = rockchip_pinctrl_parse_dt(pdev, info);if (ret)return ret;info->pctl_dev = devm_pinctrl_register(&pdev->dev, ctrldesc, info);if (IS_ERR(info->pctl_dev)) {dev_err(&pdev->dev, "could not register pinctrl driver\n");return PTR_ERR(info->pctl_dev);}return 0;
}

2.6函数操作集的具体实现

都是调用pinctrl_dev_get_drvdata函数来处理


static const struct pinctrl_ops rockchip_pctrl_ops = {.get_groups_count	= rockchip_get_groups_count,.get_group_name		= rockchip_get_group_name,.get_group_pins		= rockchip_get_group_pins,.dt_node_to_map		= rockchip_dt_node_to_map,.dt_free_map		= rockchip_dt_free_map,
};


static const struct pinmux_ops rockchip_pmx_ops = {.get_functions_count	= rockchip_pmx_get_funcs_count,.get_function_name	= rockchip_pmx_get_func_name,.get_function_groups	= rockchip_pmx_get_groups,.set_mux		= rockchip_pmx_set,
};


static const struct pinconf_ops rockchip_pinconf_ops = {.pin_config_get			= rockchip_pinconf_get,.pin_config_set			= rockchip_pinconf_set,.is_generic			= true,
};

三，dt_node_to_map函数

设备树（Device Tree）中存放的是对硬件设备信息的描述，包含了硬件设备的配置和连接信息，例如在pinctrl节点中的引脚的配置和映射关系。而rockchip_dt_node_to_map函数的作用就是根据设备树中的节点信息，生成对应的引脚映射数组。这个映射数组将描述硬件功能（如复用功能和配置信息）与设备树中的引脚信息进行绑定。

3.1pinctrl_map结构体

struct pinctrl_map{const char*dev_name; //设备名称const char*name;     //映射名称enum pinctrl_map_type type;//映射类型const char *ctrl_dev_name; //控制设备名称union{struct pinctrl_map_mux mux;         //复用映射数据struct pinctrl_map_configs configs; //配置映射数据}data;
};

需要将设备树上的信息来转化为驱动中可以用的函数，放在pinctrl_map结构体中

3.2dt_node_to_map流程分析

/**传入参数：*1，pin control class device*2，设备树中的一个node信息*3，略*4，略*/
static int rockchip_dt_node_to_map(struct pinctrl_dev *pctldev,struct device_node *np,struct pinctrl_map **map, unsigned *num_maps)
{//获取pinctrl信息struct rockchip_pinctrl *info = pinctrl_dev_get_drvdata(pctldev);const struct rockchip_pin_group *grp;struct pinctrl_map *new_map;            //要转化为的map数据struct device_node *parent;             //存放传入节点的父节点int map_num = 1;int i;/** 通过节点的名字获取组的信息，并且检查是否需要创建配置映射*/grp = pinctrl_name_to_group(info, np->name);if (!grp) {dev_err(info->dev, "unable to find group for node %pOFn\n",np);return -EINVAL;}/**grp->npins:是获取的组里引脚的数量*/map_num += grp->npins;/**分配map_num数量的内存，首地址放在new_map中*/new_map = kcalloc(map_num, sizeof(*new_map), GFP_KERNEL);if (!new_map)return -ENOMEM;*map = new_map;*num_maps = map_num;/* create mux map */parent = of_get_parent(np);if (!parent) {kfree(new_map);return -EINVAL;}//引脚配置信息的父节点写入map中new_map[0].type = PIN_MAP_TYPE_MUX_GROUP;new_map[0].data.mux.function = parent->name;new_map[0].data.mux.group = np->name;of_node_put(parent);/* create config map */new_map++;for (i = 0; i < grp->npins; i++) {                //遍历每一个成员//引脚配置信息写入map中new_map[i].type = PIN_MAP_TYPE_CONFIGS_PIN;new_map[i].data.configs.group_or_pin =pin_get_name(pctldev, grp->pins[i]);new_map[i].data.configs.configs = grp->data[i].configs;new_map[i].data.configs.num_configs = grp->data[i].nconfigs;}dev_dbg(pctldev->dev, "maps: function %s group %s num %d\n",(*map)->data.mux.function, (*map)->data.mux.group, map_num);return 0;
}

四，开发板上用到的pinctrl

在设备树下的两个部分：

//1，在rk3568-evb1-ddr4-v10.dtsi文件的根目录下//是一个设备，pinctrl的客户端rk_485_ctl: rk-485-ctl {compatible = "topeet,rs485_ctl";gpios = <&gpio0 22 GPIO_ACTIVE_HIGH>;pinctrl-names = "default";pinctrl-0 = <&rk_485_gpio>;    //这里就是引用了2部分的rk_485_gpio};//2，在rk3568-evb1-ddr4-v10.dtsi里的
//服务端
&pinctrl {cam {camera_pwr: camera-pwr {rockchip,pins =/* camera power en */<0 RK_PC1 RK_FUNC_GPIO &pcfg_pull_none>;};};headphone {hp_det: hp-det {rockchip,pins = <3 RK_PC2 RK_FUNC_GPIO &pcfg_pull_up>;};};rk_485{rk_485_gpio:rk-485-gpio {rockchip,pins = <3 13 RK_FUNC_GPIO &pcfg_pull_none>;};};
};