pwm驱动接口编写

#include <linux/init.h>#include <linux/module.h>#include <linux/kernel.h>#include <linux/fs.h>#include <linux/io.h>#include <linux/cdev.h>#include <linux/slab.h>#include <linux/ioctl.h>#include <linux/platform_device.h>#include <plat/gpio-cfg.h>#include "ioctl.h"#define DEVICE_MAJOR 250#define DEVICE_MINOR 0#define DEVICE_NUM   1#define DEVICE_NAME  "fspwm"#define GPD_BASE     0xE0300080#define PWM_BASE     0xEA000000struct gpioreg {int __iomem *gpdcon;};struct pwmreg {int __iomem *tcfg0;int __iomem *tcfg1;int __iomem *tcon;int __iomem *tcntb;int __iomem *tcmpb;};struct fsdev {struct cdev cdev;struct gpioreg gpioreg;struct pwmreg pwmreg;struct platform_device *pdev;};static struct fsdev *fspwm;static int fspwm_open(struct inode *inode, struct file *filp){int ret = 0;int nr;struct fsdev *dev;struct platform_device *pdev;dev = container_of(inode->i_cdev, struct fsdev, cdev);filp->private_data = dev;pdev = dev->pdev;if (!request_mem_region(GPD_BASE, 4, "fspwmcon")) {dev_err(&pdev->dev, "request memory region failure\n");return -EIO;}if (!request_mem_region(PWM_BASE, 12, "fspwmcon")) {dev_err(&pdev->dev, "request memory region failure\n");return -EIO;}nr = *((int *)(pdev->dev.platform_data));if (!request_mem_region(PWM_BASE + 12 + nr * 12, 12, "fspwmtmr")) {dev_err(&pdev->dev, "request memory region failure\n");return -EIO;}dev->gpioreg.gpdcon= ioremap(GPD_BASE, 4);if (!dev->gpioreg.gpdcon) {dev_err(&pdev->dev, "ioremap gpdcon failure\n");ret = -EINVAL;}dev->pwmreg.tcfg0 = ioremap(PWM_BASE, 12);if (!dev->pwmreg.tcfg0) {dev_err(&pdev->dev, "ioremap tcfg0 failure\n");ret = -EINVAL;}dev->pwmreg.tcfg1 = dev->pwmreg.tcfg0 + 1;dev->pwmreg.tcon = dev->pwmreg.tcfg0 + 2;dev->pwmreg.tcntb = ioremap(PWM_BASE + 12 + nr * 12, 12);if (!dev->pwmreg.tcntb) {dev_err(&pdev->dev, "ioremap tcntb failure\n");ret = -EINVAL;}dev->pwmreg.tcmpb = dev->pwmreg.tcntb + 1;iowrite32((ioread32(dev->gpioreg.gpdcon) & ~(0xF << nr * 4)) | (0x2 << nr * 4), dev->gpioreg.gpdcon);/* Initialize pwm timer1 */// Set prescaler for timer 1, 0xfiowrite32(ioread32(dev->pwmreg.tcfg0) & ~0xFF, dev->pwmreg.tcfg0);// Set divider mux for timer 1, 1/8iowrite32((ioread32(dev->pwmreg.tcfg1) & ~(0xF << nr * 4)) | (0x2 << nr * 4), dev->pwmreg.tcfg1);iowrite32(6000, dev->pwmreg.tcntb);iowrite32(3000, dev->pwmreg.tcmpb);// Timer1: Stop; Manual Update : 1; Output Inverter On; Auto Reload Oniowrite32((ioread32(dev->pwmreg.tcon) & ~(0xF << 8)) | (0xE << 8), dev->pwmreg.tcon);return ret;}static int fspwm_release(struct inode *inode, struct file *filp){struct fsdev *dev = filp->private_data;int nr = *((int *)(dev->pdev->dev.platform_data));iowrite32(ioread32(dev->gpioreg.gpdcon) & ~(0xF << nr * 4), dev->gpioreg.gpdcon);iounmap(dev->gpioreg.gpdcon);iounmap(dev->pwmreg.tcfg0);iounmap(dev->pwmreg.tcntb);release_mem_region(GPD_BASE, 4);release_mem_region(PWM_BASE, 12);release_mem_region(PWM_BASE + 12 + nr * 12, 12);return 0;}static int fspwm_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg){struct fsdev *dev = filp->private_data;switch (cmd) {case BEEP_ON:// Start Timer1iowrite32((ioread32(dev->pwmreg.tcon) & ~(0xF<<8)) | (0xD << 8), dev->pwmreg.tcon);break;case BEEP_OFF:// Stop Timer1iowrite32(ioread32(dev->pwmreg.tcon) & ~(0x1<<8), dev->pwmreg.tcon);break;case SET_CNT:iowrite32(arg, dev->pwmreg.tcntb);iowrite32(arg / 2, dev->pwmreg.tcmpb);break;case SET_PRE:iowrite32((ioread32(dev->pwmreg.tcfg0) & ~(0xFF)) | (arg & 0xFF), dev->pwmreg.tcfg0);break;default:break;}return 0;}static struct file_operations fspwm_fops = {.owner = THIS_MODULE,.open = fspwm_open,.release = fspwm_release,.ioctl = fspwm_ioctl,};int fspwm_probe(struct platform_device *pdev){int ret;dev_t devno;fspwm = kmalloc(sizeof(struct fsdev), GFP_KERNEL);if (!fspwm) {dev_err(&pdev->dev, "kmalloc failure\n");return -ENOMEM;}devno = MKDEV(DEVICE_MAJOR, DEVICE_MINOR);ret = register_chrdev_region(devno, DEVICE_NUM, DEVICE_NAME);if(ret) {dev_err(&pdev->dev, "register char device region failed\n");goto out_kfree;}cdev_init(&fspwm->cdev, &fspwm_fops);fspwm->cdev.owner = THIS_MODULE;ret = cdev_add(&fspwm->cdev, devno, DEVICE_NUM);if (ret < 0) {dev_err(&pdev->dev, "add cdev failure\n");goto out_ureg_region;}fspwm->pdev = pdev;return 0;out_ureg_region:unregister_chrdev_region(devno, DEVICE_NUM);out_kfree:kfree(fspwm);return ret;}int fspwm_remove(struct platform_device *pdev){dev_t devno;cdev_del(&fspwm->cdev);devno = MKDEV(DEVICE_MAJOR, DEVICE_MINOR);unregister_chrdev_region(devno, DEVICE_NUM);return 0;}static struct platform_driver fspwm_drv = {.probe = fspwm_probe,.remove = fspwm_remove,.driver = {.name = "fspwm",.owner = THIS_MODULE,},};static int __init fspwm_init(void){return platform_driver_register(&fspwm_drv);}static void __exit fspwm_exit(void){platform_driver_unregister(&fspwm_drv);}module_init(fspwm_init);module_exit(fspwm_exit);MODULE_LICENSE("Dual BSD/GPL");MODULE_AUTHOR("Kevin Jiang <[e-mail]>");MODULE_DESCRIPTION("fspwm sample");