Linux regulator系统(1)
1. 概念:
Regulator : 电源芯片, 比如电压转换芯片
Consumer : 消费者,使用电源的部件, Regulator是给Consumer供电的
machine : 单板,上面焊接有Regulator和Consumer
Constraints : 约束, 比如某个电源管理芯片输出的电压范围
Supply : 提供电源的部件, Regulator就是一个Supply; Regulator A可以给Regulator B供电, 那么Regulator B的Supply就是A
2. 写驱动程序:
(1). regulator驱动:
注册一个platform_driver: 在它的probe函数里分配、设置、注册一个regulator
"设置"里要做的事情: 实现regulator的操作, 比如enable, disable, set_voltage
(2). machine(单板)驱动:
注册一个platform_device: 在它的私有数据里指定regulator和consume的对应关系(这个电源芯片给哪一个部件供电)
指定约束条件(比如电压范围)
(3). consumer使用此电源的设备驱动:
使用即可: regulator_get, regulator_enable, regulator_disable, regulator_set_voltage....
注: 这只是没有使用设备树的情况下是这样的,其实就是以平台设备模型注册一个regulator,然后consumer去使用。
3. 不使用设备树的regulator_register流程分析:
// 分配regulator_dev rdev = kzalloc(sizeof(struct regulator_dev), GFP_KERNEL); /* set regulator constraints */ set_machine_constraints add_regulator_attributes /* add consumers devices */ set_consumer_device_supply 在regulator_map_list链表里生成一项regulator_map: 它里面有dev_name(consumer的名字),supply(cosumer的电源引脚名字) // 把regulator_dev放入regulator_list list_add(&rdev->list, ®ulator_list);
4. 使用设备树的regulator_register()和regulator_get()流程分析:
regulator_register(const struct regulator_desc *, const struct regulator_config *) //drivers/regulator/core.c 先自行各种检查,然后构造一个struct regulator_dev,从设备树中获取它的各种属性 regulator_of_get_init_data //drivers/regulator/of_regulator.c of_get_regulation_constraints //drivers/regulator/of_regulator.c 通过设备树构造init_data,和约束 若设备树中指定了“regulator-initial-mode”且regulator_desc.of_map_mode()存在,则调用它 初始化rdev->consumer_list,rdev->list,rdev->notifier,指定rdev->disable_work=regulator_disable_work 如果init_data->regulator_init()存在则调用 判断是不是gpio控制的regulator,如果是就调用regulator_ena_gpio_request() 使rdev->dev.class = ®ulator_class,此时sysfs下会有"regulator"文件夹,其下有regulator_dev_attrs中列出的文件。 自动递增设置&rdev->dev的name为"regulator.%lu" "regulator"下的"regulator.%lu"下才会有regulator_dev_attrs中列出的文件了。 set_machine_constraints device_register(&rdev->dev) //注册到设备模型 dev_set_drvdata(&rdev->dev, rdev); rdev_init_debugfs(rdev);
使用设备树的regulator_get()流程分析: struct regulator *regulator_get(struct device *dev, const char *id) //drivers/regulator/core.c, arg2为consumer的电源引脚 regulator_dev_lookup //drivers/regulator/core.c 使用devname与全局链表regulator_map_list中的每一项struct regulator_map->dev_name进行匹配,并返回匹配的struct regulator_dev结构体。 regulator_resolve_supply 还要和rdev->supply_name的名字逐个比较 create_regulator 根据struct regulator_dev创建一个struct regulator并返回
5.驱动示例代码
/* 文件名:machine.c 作为一个regulator平台设备模型的设备端。 * 参考: arch\arm\mach-omap2\board-2430sdp.c * 这里只是注册一个单板的所有regulator的平台设备端,目前这类文件应该被设备树给替代了 */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/err.h> #include <linux/platform_device.h> #include <linux/regulator/driver.h> #include <linux/mfd/core.h> /* 分配/设置/注册regulator_init_data */ #if 0 regulator_consumer_supply: const char *dev_name; /* consumer的名字 */ const char *supply; /* consumer的电源引脚名称 */ #endif static struct regulator_consumer_supply myregulator_supplies[] = { REGULATOR_SUPPLY("VCC", "mylcd"), /*此regulator是对设备"mylcd"上的"VCC"引脚供电的*/ }; static struct regulator_init_data myregulator_init_data = { .constraints = { .min_uV = 12000000, .max_uV = 12000000, .valid_modes_mask = REGULATOR_MODE_NORMAL, .valid_ops_mask = REGULATOR_CHANGE_STATUS, }, .num_consumer_supplies = ARRAY_SIZE(myregulator_supplies), .consumer_supplies = myregulator_supplies, }; static void myregulator_release(struct device * dev) { } static struct platform_device myregulator_dev = { .name = "myregulator", /* 平台设备设备端名字*/ .id = -1, .dev = { .release = myregulator_release, .platform_data = &myregulator_init_data, }, }; /*使用设备树后就不再需要注册平台设备端了*/ static int myregulator_machine_init(void) { platform_device_register(&myregulator_dev); return 0; } static void myregulator_machine_exit(void) { platform_device_unregister(&myregulator_dev); } module_init(myregulator_machine_init); module_exit(myregulator_machine_exit); MODULE_LICENSE("GPL v2");
/* 文件名:regulator.c 作为一个regulator平台设备模型的驱动端。 * 参考: drivers/regulator/tps6105x-regulator.c * 其实machine.c充当的是平台设备的设备端,将单板上的所有regulator写在了一起,目前已被设备树替代。 * regulator.c充当的是平台设备的驱动端,每个regulator都可能有一个平台设备驱动端。 */ #include <linux/module.h> #include <linux/kernel.h> #include <linux/init.h> #include <linux/err.h> #include <linux/platform_device.h> #include <linux/regulator/driver.h> #include <linux/mfd/core.h> static volatile unsigned long *gpbcon; static volatile unsigned long *gpbdat; static int myregulator_enable(struct regulator_dev *rdev) { *gpbdat |= 1; /* 输出高电平 */ return 0; } static int myregulator_disable(struct regulator_dev *rdev) { *gpbdat &= ~1; /* 输出低电平 */ return 0; } static int myregulator_is_enabled(struct regulator_dev *rdev) { if (*gpbdat & 1) return 1; else return 0; } static struct regulator_ops myregulator_ops = { .enable = myregulator_enable, .disable = myregulator_disable, .is_enabled = myregulator_is_enabled, }; static struct regulator_desc myregulator_desc = { .name = "myregulator", .ops = &myregulator_ops, .type = REGULATOR_VOLTAGE, .id = 0, .owner = THIS_MODULE, .n_voltages = 1, /*只提供一种电压值得*/ }; static struct regulator_dev *myregulator_dev; static int myregulator_probe(struct platform_device *pdev) { struct regulator_init_data *init_data = dev_get_platdata(&pdev->dev); /*可以在platform_driver初始化的时候对dev赋值*//* 分配/设置/注册 regulator */ myregulator_dev = regulator_register(&myregulator_desc, &pdev->dev, init_data, NULL, NULL); if (IS_ERR(myregulator_dev)) { printk("regulator_register error!\n"); return -EIO; } return 0; } static int myregulator_remove(struct platform_device *pdev) { regulator_unregister(myregulator_dev); return 0; } struct platform_driver myregulator_drv = { .probe = myregulator_probe, .remove = myregulator_remove, .driver = { .name = "myregulator", /* 驱动上面regulator平台设备的设备端 */ } }; static int myregulator_init(void) { platform_driver_register(&myregulator_drv); return 0; } static void myregulator_exit(void) { platform_driver_unregister(&myregulator_drv); } module_init(myregulator_init); module_exit(myregulator_exit); MODULE_LICENSE("GPL v2");
/* 文件名:consumer_lcd.c 作为一个consumer驱动 * */ static int mylcd_open(struct fb_info *info, int user) { pm_runtime_get_sync(&lcd_dev.dev); return 0; } static int mylcd_release(struct fb_info *info, int user) { pm_runtime_mark_last_busy(&lcd_dev.dev); pm_runtime_put_sync_autosuspend(&lcd_dev.dev); return 0; } static int lcd_suspend_notifier(struct notifier_block *nb, unsigned long event, void *dummy) { switch (event) { case PM_SUSPEND_PREPARE: printk("lcd suspend notifiler test: PM_SUSPEND_PREPARE\n"); return NOTIFY_OK; case PM_POST_SUSPEND: printk("lcd suspend notifiler test: PM_POST_SUSPEND\n"); return NOTIFY_OK; default: return NOTIFY_DONE; } } static struct notifier_block lcd_pm_notif_block = { .notifier_call = lcd_suspend_notifier, }; static void lcd_release(struct device * dev) { } static struct platform_device lcd_dev = { /* regulator匹配1 */ .name = "mylcd", .id = -1, .dev = { .release = lcd_release, }, }; static struct regulator *myregulator; static int lcd_probe(struct platform_device *pdev) { myregulator = regulator_get(pdev->dev, "VCC"); /* regulator 匹配2 */ if (IS_ERR(myregulator)) { printk("regulator_get error!\n"); return -EIO; } regulator_enable(myregulator); /*没有它会报unblance regulator disable of myregulator*/ pm_runtime_set_active(&pdev->dev); pm_runtime_use_autosuspend(&pdev->dev); pm_runtime_enable(&pdev->dev); return 0; } static int lcd_remove(struct platform_device *pdev) { regulator_put(myregulator); pm_runtime_disable(&pdev->dev); return 0; } static int lcd_suspend(struct device *dev) { int i; unsigned long *dest = &lcd_regs_backup; unsigned long *src = lcd_regs; for (i = 0; i < sizeof(lcd_regs_backup)/sizeof(unsigned long); i++) { dest[i] = src[i]; } lcd_regs->lcdcon1 &= ~(1<<0); /* 关闭LCD本身 */ //*gpbdat &= ~1; /* 关闭背光 */ regulator_disable(myregulator); return 0; } static int lcd_resume(struct device *dev) { int i; unsigned long *dest = lcd_regs; unsigned long *src = &lcd_regs_backup; struct clk *clk = clk_get(NULL, "lcd"); clk_enable(clk); clk_put(clk); for (i = 0; i < sizeof(lcd_regs_backup)/sizeof(unsigned long); i++) { dest[i] = src[i]; } regulator_enable(myregulator); return 0; } static struct dev_pm_ops lcd_pm = { .suspend = lcd_suspend, .resume = lcd_resume, .runtime_suspend = lcd_suspend, .runtime_resume = lcd_resume, }; struct platform_driver lcd_drv = { .probe = lcd_probe, .remove = lcd_remove, .driver = { .name = "mylcd", .pm = &lcd_pm, } }; static int lcd_init(void) { /* 电源管理 */ register_pm_notifier(&lcd_pm_notif_block); platform_device_register(&lcd_dev); platform_driver_register(&lcd_drv); return 0; } static void lcd_exit(void) { unregister_pm_notifier(&lcd_pm_notif_block); platform_device_unregister(&lcd_dev); platform_driver_unregister(&lcd_drv); } module_init(lcd_init); module_exit(lcd_exit); MODULE_LICENSE("GPL");
posted on 2018-11-17 21:28 Hello-World3 阅读(6095) 评论(1) 编辑 收藏 举报