path: root/ina260.c

#include "linux/module.h"
#include "linux/uaccess.h"
#include "linux/i2c.h"
#include "linux/kobject.h"
#include "linux/slab.h"
#include "linux/kernel.h"
#include <linux/sysfs.h>
#include <linux/hwmon.h>
#include <linux/regmap.h>

// ina260 chip registers
#define INA260_REG_CONFIGURATION 0x00
#define INA260_REG_CURRENT 0x01
#define INA260_REG_VOLTAGE 0x02
#define INA260_REG_POWER 0x03
#define INA260_REG_MASKENABLE 0x06
#define INA260_REG_ALERTLIMIT 0x07
#define INA260_REG_MANUFACTURER 0xFE
#define INA260_REG_DIE 0xFF

#undef current

static struct regmap_config ina260_regmap_config = {
	.reg_bits = 8,
	.val_bits = 16,
};

#define INA260_REG_SHOW(_attr,_reg) \
static ssize_t _attr##_show(struct device *dev, struct device_attribute *attr, char *buf) \
{ \
    int rvalue; struct client_data *cdata=dev_get_drvdata(dev); \
    if(ina260_read_register(cdata,(_reg),&rvalue)) \
        return -1; \
    return sprintf(buf, "%x\n", rvalue); \
}

#define INA260_REG_STORE(_attr,_reg) \
static ssize_t _attr##_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) \
{ \
    int uvalue; struct client_data *cdata=dev_get_drvdata(dev); \
    if(kstrtoint(buf, 0,&uvalue)) \
        return -EINVAL; \
    if(ina260_write_register(cdata, (_reg), uvalue)) \
        return -1; \
    return count; \
}


#define HWMON_CHANNEL_INFO(stype, ...)	\
	(&(struct hwmon_channel_info) {	\
		.type = hwmon_##stype,	\
		.config = (u32 []) {	\
			__VA_ARGS__, 0	\
		}			\
	})

// ina260 average modes list
static int ina260_avgs[8]={
    1,4,16,64,128,256,512,1024
};

// ina260 operating modes list
static char ina260_modes[8][42]={
    "Power-Down (or Shutdown)","Shunt Current, Triggered",
    "Bus Voltage, Triggered","Shunt Current and Bus Voltage, Triggered", 
    "Power-Down (or Shutdown)","Shunt Current, Continuous","Bus Voltage, Continuous",
    "Shunt Current and Bus Voltage, Continuous"
};

// ina260 conversion times list
static char ina260_ishcts_vbusct[8][9]={
    "140 µs", "204 µs","332 µs", "588 µs","1.1 ms", "2.116 ms","4.156 ms","8.244 ms"
};


// Data attached to i2c clients
struct client_data {
    struct i2c_client *client;
    unsigned char reg; // Slave selected register
    struct regmap *regmap;
};

static const struct i2c_device_id ina260_ids[] = {
    { "ina260", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c,ina260_ids);

/**
 * @brief Read from ina260 registers
 * 
 * @param cdata client data to use to communicate
 * @param reg register to read
 * @param value register content output
 * @return int 0 on success, 1 on communication errors
 */
static int ina260_read_register(struct client_data* cdata, unsigned char reg, int *value){
    unsigned char bytes[2];
    /*if(cdata->reg == reg){
        if(i2c_master_recv(cdata->client,bytes,2)<0)
            return 1;
    } else {
        if(i2c_master_send(cdata->client,&reg,1)<0)
            return 1;
        cdata->reg = reg;
        if(i2c_master_recv(cdata->client,bytes,2)<0)
            return 1;
    }*/
    return regmap_read(cdata->regmap, reg, value);
   // *value=(bytes[0]<<8) | bytes[1];
    //return 0;
}

/**
 * @brief Write to ina260 registers
 * 
 * @param cdata client data to use to communicate
 * @param reg register to write to
 * @param value value to write in @a reg
 * @return int 0 on success, 1 on communication errors
 */
static int ina260_write_register(struct client_data* cdata, unsigned char reg, int value){
    unsigned char data[3];
    data[0]=reg;
    data[1]=(value>>8) & 0xFF; // MSB
    data[2]=value & 0xFF;   // LSB
    if(i2c_master_send(cdata->client,data,3)<0)
        return 1;
    return 0;
}


static int ina260_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
		       u32 attr, int channel, long *val)
{
    int rvalue;
    struct client_data *cdata=dev_get_drvdata(dev);
    if(type == hwmon_power){
        if(ina260_read_register(cdata, INA260_REG_POWER,&rvalue))
            return -1;
        *val=10*rvalue*1000;
    } else if (type == hwmon_curr){
        if(ina260_read_register(cdata, INA260_REG_CURRENT,&rvalue))
            return -1;
        *val=((rvalue*25/100) + rvalue)*100+(rvalue*25%100);
        *val/=100;
    } else if (type == hwmon_in){
        if(ina260_read_register(cdata, INA260_REG_VOLTAGE,&rvalue))
            return -1;

        *val=((rvalue*25/100) + rvalue)*100+(rvalue*25%100);
        *val/=100;
    }

	return 0;
}

static int ina260_hwmon_write(struct device *dev, enum hwmon_sensor_types type,
		       u32 attr, int channel, long val)
{
    return 0;
}

INA260_REG_SHOW(configuration,INA260_REG_CONFIGURATION)
INA260_REG_SHOW(current,INA260_REG_CURRENT)
INA260_REG_SHOW(bus_voltage,INA260_REG_VOLTAGE)
INA260_REG_SHOW(power,INA260_REG_POWER)
INA260_REG_SHOW(mask_enable,INA260_REG_MASKENABLE)
INA260_REG_SHOW(alert_limit,INA260_REG_ALERTLIMIT)
INA260_REG_SHOW(manufacturer_id,INA260_REG_MANUFACTURER)
INA260_REG_SHOW(die_id,INA260_REG_DIE)

INA260_REG_STORE(configuration,INA260_REG_CONFIGURATION)
INA260_REG_STORE(current,INA260_REG_CURRENT)
INA260_REG_STORE(bus_voltage,INA260_REG_VOLTAGE)
INA260_REG_STORE(power,INA260_REG_POWER)
INA260_REG_STORE(mask_enable,INA260_REG_MASKENABLE)
INA260_REG_STORE(alert_limit,INA260_REG_ALERTLIMIT)


static umode_t ina260_hwmon_is_visible(const void *drvdata,
				 enum hwmon_sensor_types type,
				 u32 attr, int channel){
                    return 0444;
                 }
static const struct hwmon_channel_info *  ina260_hwmon_info[] = {
    HWMON_CHANNEL_INFO(in,HWMON_I_INPUT),
	HWMON_CHANNEL_INFO(power,HWMON_P_INPUT),
    HWMON_CHANNEL_INFO(curr,HWMON_C_INPUT),
	NULL
};
static const struct hwmon_ops ina260_hwmon_ops = {
    .is_visible = ina260_hwmon_is_visible,
	.read = ina260_hwmon_read,
	.write = ina260_hwmon_write,
};

static const struct hwmon_chip_info ina260_chip_info = {
	.ops = &ina260_hwmon_ops,
	.info = ina260_hwmon_info,
};
// ----- Registers -----
static DEVICE_ATTR_RW(configuration);
static DEVICE_ATTR_RW(current);
static DEVICE_ATTR_RW(bus_voltage);
static DEVICE_ATTR_RW(power);
static DEVICE_ATTR_RW(mask_enable);
static DEVICE_ATTR_RW(alert_limit);
static DEVICE_ATTR_RO(manufacturer_id);
static DEVICE_ATTR_RO(die_id);
static struct attribute *registers_attrs[] = {
    &dev_attr_configuration.attr,
    &dev_attr_current.attr,
    &dev_attr_bus_voltage.attr,
    &dev_attr_power.attr,
    &dev_attr_mask_enable.attr,
    &dev_attr_alert_limit.attr,
    &dev_attr_manufacturer_id.attr,
    &dev_attr_die_id.attr,
    NULL,   
};
static const struct attribute_group registers_group = {
	.attrs = registers_attrs,
    .name = "registers"
};


/**
 * @brief Compare on ina260 register to a supplied value
 * 
 * @param client i2c client to use for communications
 * @param reg register to use for comparison
 * @param value register expected value
 * @return int 0 if register contains value and 1 otherwise
 */
static int ina260_probe_register(struct i2c_client *client, unsigned char reg, int value){
    unsigned char bytes[2];
    if(i2c_master_send(client,&reg,1)<0)
        return 1;
    if(i2c_master_recv(client,bytes,2)<0)
        return 1;
    return ((bytes[0]<<8) | bytes[1])!=value;
}

const struct attribute_group *extra_groups[] = {
    &registers_group,
    NULL
};

static int ina260_probe_new(struct i2c_client *client){
    struct client_data *p;
    struct device *hwmon_dev;

    // Attempt device discovery:
    if(ina260_probe_register(client,INA260_REG_MANUFACTURER,0x5449) ||
       ina260_probe_register(client,INA260_REG_DIE,0x2270)){
        printk("ina260 probe fails bus=%d address=0x%02x\n",client->adapter->nr,client->addr);
        return 1;
    }
    // Initialize client data:
    printk("ina260 detected bus=%d address=0x%02x\n",client->adapter->nr,client->addr);
    p=kzalloc(sizeof(struct client_data),GFP_KERNEL);
    p->client=client;
    p->reg=INA260_REG_DIE; // Maintain cache coherence
	p->regmap = devm_regmap_init_i2c(client, &ina260_regmap_config);

    hwmon_dev=hwmon_device_register_with_info(&client->dev,client->name,p,
    &ina260_chip_info,extra_groups);
	if (IS_ERR(hwmon_dev))
		return PTR_ERR(hwmon_dev);
    return 0;
}

static int ina260_remove(struct i2c_client *client){
    struct client_data *p=i2c_get_clientdata(client);
    kfree(p);
    hwmon_device_unregister(&client->dev);
    printk("ina260 removed bus=%d address=0x%02x\n",client->adapter->nr,client->addr);
    return 0;
}

static struct i2c_driver ina260_driver = {
    .class = I2C_CLASS_HWMON,
	.driver = {
		.name = "ina260"
	},
	.probe_new = ina260_probe_new,
	.remove = ina260_remove,
	.id_table = ina260_ids
};

static int __init ina260_init(void){
    i2c_add_driver(&ina260_driver);
    return 0;
}

static void __exit ina260_exit(void){
    i2c_del_driver(&ina260_driver);
}

module_init(ina260_init);
module_exit(ina260_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Loïc Guegan");
MODULE_DESCRIPTION("INA260 Texas Instruments");
MODULE_VERSION("1.0");