i2c regmap

Author: 54shady

debug/i2c/Makefile

@@ -15,6 +15,7 @@ DEBFLAGS = -O2
 endif
 
 obj-m := myi2c.o
+obj-m += i2c_regmap.o
 KERNELDIR ?= /lib/modules/$(shell uname -r)/build
 CC ?= gcc
 PWD := $(shell pwd)

debug/i2c/i2c_regmap.c

@@ -0,0 +1,210 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/of_gpio.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/regmap.h>
+
+/* describe in device tree */
+#if 0
+&i2c0 {
+	myi2c@5a {
+		compatible = "myi2c";
+		status = "okay";
+		reg = <0x5a>;
+	};
+}
+#endif
+
+struct myi2c_chip {
+	char name[100];
+	struct i2c_client	*client;
+	struct device		*dev;
+	struct regmap *regmap;
+};
+struct myi2c_chip chip;
+
+/* regmap config */
+#define REGISTER_NUMBERS 0xF5
+static const struct regmap_config regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = REGISTER_NUMBERS,
+	.cache_type = REGCACHE_RBTREE,
+};
+
+static ssize_t myi2c_debug_show(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
+{
+    unsigned int rval;
+	//struct myi2c_chip *chip;
+	//chip = container_of(dev, struct myi2c_chip, dev);
+	printk("chip name = %s\n", chip.name);
+
+	printk("regmap = %p\n", &chip.regmap);
+	if (regmap_read(chip.regmap, 0x22, &rval) == 0)
+	{
+		printk("reg map read ERROR\n");
+		return -1;
+	}
+	else
+	{
+		printk("reg map read ok\n");
+		if ((rval < 0) || (rval == 0xff))
+			printk("The device is not act8846\n");
+	}
+
+//	printk("myi2c reg[0x22] = %d\n", rval);
+	return sprintf(buf,"REG[0x22]=%d\n", rval);
+}
+
+static ssize_t myi2c_debug_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	int tmp;
+	tmp = simple_strtoul(buf, NULL, 16);
+	return count;
+}
+
+static DEVICE_ATTR(myi2c_debug, S_IRUGO | S_IWUSR, myi2c_debug_show, myi2c_debug_store);
+
+static struct attribute *myi2c_attrs[] = {
+	&dev_attr_myi2c_debug.attr,
+	NULL,
+};
+
+static const struct attribute_group myi2c_attr_group = {
+	.attrs = myi2c_attrs,
+};
+
+/* I2C device id */
+static const struct i2c_device_id myi2c_id_table[] = {
+	{ "myi2c", 0 },
+	{},
+};
+MODULE_DEVICE_TABLE(i2c, myi2c_id_table);
+
+static const struct of_device_id of_myi2c_match[] = {
+	{ .compatible = "myi2c" },
+	{ /* Sentinel */ }
+};
+
+static int myi2c_probe(struct i2c_client *client,
+				  const struct i2c_device_id *id)
+{
+	//struct myi2c_chip *chip;
+	int ret;
+	const struct of_device_id *match;
+	unsigned int rval;
+
+	/* 检查DT */
+	if (client->dev.of_node) {
+		match = of_match_device(of_myi2c_match, &client->dev);
+		if (!match) {
+			printk("Failed to find matching dt id\n");
+			return -EINVAL;
+		}
+	}
+
+#if 0
+	/* 为自定义结构提分配数据空间 */
+	chip = kzalloc(sizeof(struct myi2c_chip), GFP_KERNEL);
+	//chip = devm_kzalloc(&client->dev, sizeof(struct myi2c_chip), GFP_KERNEL);
+	if (chip == NULL) {
+		ret = -ENOMEM;
+		printk("No enough memory ERROR!!\n");
+	}
+#endif
+	/* 设置chip */
+	strcpy(chip.name, "myi2ctest");
+	chip.client = client;
+	chip.dev = &client->dev;
+
+	/* 设置client 的driver data 指向chip */
+	i2c_set_clientdata(client, &chip);
+
+	/* 映射寄存器地址 */
+	chip.regmap = devm_regmap_init_i2c(client, &regmap_config);
+	if (IS_ERR(chip.regmap)) {
+		ret = PTR_ERR(chip.regmap);
+		printk("regmap initialization failed: %d\n", ret);
+		return ret;
+	}
+
+	/* I2C 通讯 */
+	regmap_read(chip.regmap, 0x22, &rval);
+	if ((rval < 0) || (rval == 0xff)){
+		printk("The device is not act8846 %x \n",ret);
+		ret = -1;
+	}
+	printk("myi2c reg[0x22] = %d\n", rval);
+	printk("regmap = %p\n", &chip.regmap);
+
+	/* read write 0xF4 for test */
+	regmap_read(chip.regmap, 0xf4, &rval);
+	if ((rval < 0) || (rval == 0xff)){
+		printk("The device is not act8846 %x \n",ret);
+		ret = -1;
+	}
+	printk("myi2c read reg[0xf4] = %d\n", rval);
+
+	ret = regmap_write(chip.regmap, 0xf4, 1);
+	if (ret < 0) {
+		printk("myi2c set 0xf4 error!\n");
+		return -1;
+	}
+	printk("write 0xf4 = 1\n");
+	regmap_read(chip.regmap, 0xf4, &rval);
+	if ((rval < 0) || (rval == 0xff)){
+		printk("The device is not act8846 %x \n",ret);
+		ret = -1;
+	}
+	printk("myi2c read reg[0xf4] = %d\n", rval);
+
+	ret = sysfs_create_group(&client->dev.kobj, &myi2c_attr_group);
+	if (ret) {
+		printk("failed to create sysfs device attributes\n");
+		return -1;
+	}
+	printk("Probe Done\n");
+
+	return 0;
+}
+
+static int myi2c_remove(struct i2c_client *client)
+{
+	sysfs_remove_group(&client->dev.kobj, &myi2c_attr_group);
+
+	return 0;
+}
+
+static struct i2c_driver myi2c_driver = {
+	.driver	= {
+		.name	= "myi2c",
+		.owner	= THIS_MODULE,
+		.of_match_table = of_myi2c_match,
+	},
+	.probe		= myi2c_probe,
+	.remove		= myi2c_remove,
+	.id_table	= myi2c_id_table,
+};
+
+static int myi2c_init(void)
+{
+	int ret;
+	ret = i2c_add_driver(&myi2c_driver);
+	return ret;
+}
+
+static void myi2c_exit(void)
+{
+	i2c_del_driver(&myi2c_driver);
+}
+
+module_init(myi2c_init);
+module_exit(myi2c_exit);
+MODULE_LICENSE("GPL");