驅動目的：
從eeprom的0x2000地址開始讀出4096byte大小資料
驅動如下：
#include <linux/module.h> #include <linux/init.h> #include <linux/delay.h> #include <linux/spi/spi.h> #include <linux/gpio.h> #include <linux/debugfs.h> #include <linux/string.h> #include <linux/of_gpio.h> #include <linux/delay.h> #include <linux/spi/spi.h> #include <linux/kdev_t.h> #include <linux/regmap.h> #include <linux/vmalloc.h> #include <sound/core.h> #include <sound/soc.h> #include <linux/slab.h> #include <linux/fs.h> #include <linux/buffer_head.h> #include <asm/segment.h> #include <asm/uaccess.h> struct eeprom_dev *eeprom; static struct kobject *eeprom_kobj; struct eeprom_dev { struct regmap *regmap; struct spi_device *spi; }; static ssize_t eeprom_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t len) { int rc = 0, i = 0, ret = 0; uint8_t txbuf[] = {0x02, 0x00, 0x00, 0x00}; uint8_t *rxbuf; unsigned long level; struct file *file; rxbuf = kmalloc(sizeof(uint8_t)*4096, GFP_KERNEL); if (eeprom == NULL) { pr_err("%s: invalid eeproms device.\n", __func__); return -1; } rc = kstrtoul(buf, 10, &level); rc = spi_write_then_read(eeprom->spi, txbuf, 4, rxbuf, 4096); // 發出地址給到eeprom file = filp_open("/data/eeprom/eeprom_flash.bin", O_RDWR | O_CREAT, 0777); i = IS_ERR(file); if (i){ printk("create file error"); printk("-----ERR===%d----",i); goto error; } ret = vfs_write(file, rxbuf, 4096, &pos); if (ret < 0){ printk("write file error"); printk("-----write_ERR===%d----",ret); } filp_close(file,NULL); kfree(rxbuf); error: return len; } static DEVICE_ATTR(eeprom_pwr, 0666, NULL, eeprom_store); static struct attribute *eeproms_attrs[] = { &dev_attr_eeprom_pwr.attr, NULL, }; static struct attribute_group eeproms_attr_group = { .attrs = eeproms_attrs, }; static int eeprom_probe(struct spi_device *spi) { int rc = 0; eeprom = devm_kzalloc(&spi->dev, sizeof(struct eeprom_dev), GFP_KERNEL); if (IS_ERR(eeprom)) { pr_err("%s: can't alloc memery for eeproms device.\n", __func__); return -1; } dev_set_drvdata(&spi->dev, eeprom); eeprom->spi = spi; eeprom_kobj = kobject_create_and_add("eeprom_node", kernel_kobj); if (!eeprom_kobj) { dev_err(&spi->dev, "kobject eeproms ENOMEM\n"); } rc = sysfs_create_group(eeprom_kobj, &eeproms_attr_group); if (rc) { pr_err("%s: sysfs create failed. rc = %d.\n", __func__, rc); } return rc; } static const struct of_device_id eeprom_match_table[] = { { .compatible = "eeprom,spi", }, {}, }; static struct spi_driver eeprom_driver = { .driver = { .name = "eeprom_driver", .owner = THIS_MODULE, .of_match_table = eeprom_match_table, }, .probe = eeprom_probe, }; static int __init eeprom_init(void) { pr_err("eeprom_init\n"); return spi_register_driver(&eeprom_driver); } static void __exit eeprom_exit(void) { pr_err("eeprom_exit\n"); return spi_unregister_driver(&eeprom_driver); } module_init(eeprom_init); module_exit(eeprom_exit); MODULE_LICENSE("GPL v2");