path: root/ina260.c

#include "linux/module.h" // to access basic module functions (module_init etc..)
#include "linux/uaccess.h" // copy_from_user() etc...
#include "linux/i2c.h"
#include "linux/kobject.h"
#include "linux/slab.h" // kzalloc()
#include "linux/kernel.h" // Kernel utility e.g kstrtol
#include <linux/sysfs.h>

#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

#define INA260_IS_ATTR(_name) (strcmp(attr->attr.name, #_name) == 0)

static int ina260_avgs[8]={
    1,4,16,64,128,256,512,1024
};

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"
};

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"
};


static struct kobject* ina260_kobj;

struct client_data {
    struct kobject kobj;
    struct i2c_client *client;
    unsigned char reg; // Client selected register
};
static const struct i2c_device_id ina260_ids[] = {
    { "ina260", 0 },
    { }
};
MODULE_DEVICE_TABLE(i2c,ina260_ids); // Allow i2c subsystem to probe

static int ina260_read_register(struct client_data* cdata, unsigned char reg, int *value){
    unsigned char bytes[2];
    if(cdata->reg == reg){
        //printk("Cache\n");
        if(i2c_master_recv(cdata->client,bytes,2)<0)
            return 1;
    } else {
        //printk("No cache\n");
        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;
    }
    *value=(bytes[0]<<8) | bytes[1];
    return 0;
}

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 ssize_t attr_show(struct kobject *_kobj, 
                      struct kobj_attribute *attr,
                     char *buf)
{
    int value;
    struct client_data *data=container_of(_kobj,struct client_data,kobj);
    unsigned char reg=INA260_REG_POWER;

    if(!INA260_IS_ATTR(power)){
        if (INA260_IS_ATTR(current)){
            reg=INA260_REG_CURRENT;
        } else if(INA260_IS_ATTR(bus_voltage)) {
            reg=INA260_REG_VOLTAGE;
        } else if(INA260_IS_ATTR(mask_enable)) {
            reg=INA260_REG_MASKENABLE;
        } else if(INA260_IS_ATTR(alert_limit)) {
            reg=INA260_REG_ALERTLIMIT;
        } else if(INA260_IS_ATTR(configuration)) {
            reg=INA260_REG_CONFIGURATION;
        } else if(INA260_IS_ATTR(manufacturer_id)) {
            reg=INA260_REG_MANUFACTURER;
        } else {
            reg=INA260_REG_DIE;
        }
    }

    if(ina260_read_register(data,reg,&value))
        return -1;

    return sprintf(buf, "%x\n", value);
}
 
 
static ssize_t attr_store(struct kobject *_kobj, 
                       struct kobj_attribute *attr,
               const char *buf, size_t count)
{
    struct client_data *cdata=container_of(_kobj,struct client_data,kobj);
    int data;
    unsigned char reg=INA260_REG_CONFIGURATION;
    if(kstrtoint(buf, 10,&data))
        return -EINVAL;

    if (INA260_IS_ATTR(mask_enable)){
        reg=INA260_REG_MASKENABLE;
    } else if (INA260_IS_ATTR(alert_limit)){
        reg=INA260_REG_ALERTLIMIT;
    }

    if(ina260_write_register(cdata, reg, data))
        return -1;

    return count;
}

static ssize_t attr_field_show(struct kobject *_kobj, 
                      struct kobj_attribute *attr,
                     char *buf)
{
    struct client_data *cdata=container_of(_kobj,struct client_data,kobj);
    int value;
    if(INA260_IS_ATTR(avg)){
        if(ina260_read_register(cdata, INA260_REG_CONFIGURATION,&value))
            return -1;
        return sprintf(buf, "%d\n", ina260_avgs[(value>>9)&0x7]);
    } else if (INA260_IS_ATTR(mode)){
        if(ina260_read_register(cdata, INA260_REG_CONFIGURATION,&value))
            return -1;
        return sprintf(buf, "%s\n", ina260_modes[value&0x7]);
    } else if (INA260_IS_ATTR(ishct)){
        if(ina260_read_register(cdata, INA260_REG_CONFIGURATION,&value))
            return -1;
        return sprintf(buf, "%s\n", ina260_ishcts_vbusct[(value>>3)&0x7]);
    } else if (INA260_IS_ATTR(vbusct)){
        if(ina260_read_register(cdata, INA260_REG_CONFIGURATION,&value))
            return -1;
        return sprintf(buf, "%s\n", ina260_ishcts_vbusct[(value>>6)&0x7]);
    } else if (INA260_IS_ATTR(aff)){
        if(ina260_read_register(cdata, INA260_REG_MASKENABLE,&value))
            return -1;
        return sprintf(buf, "%d\n", (value>>4)&0x1);
    } else if (INA260_IS_ATTR(cvrf)){
        if(ina260_read_register(cdata, INA260_REG_MASKENABLE,&value))
            return -1;
        return sprintf(buf, "%d\n", (value>>3)&0x1);
    } else if (INA260_IS_ATTR(ocl)){
        if(ina260_read_register(cdata, INA260_REG_MASKENABLE,&value))
            return -1;
        return sprintf(buf, "%d\n", (value>>15)&0x1);
    }else if (INA260_IS_ATTR(ucl)){
        if(ina260_read_register(cdata, INA260_REG_MASKENABLE,&value))
            return -1;
        return sprintf(buf, "%d\n", (value>>14)&0x1);
    }else if (INA260_IS_ATTR(bol)){
        if(ina260_read_register(cdata, INA260_REG_MASKENABLE,&value))
            return -1;
        return sprintf(buf, "%d\n", (value>>13)&0x1);
    }else if (INA260_IS_ATTR(bul)){
        if(ina260_read_register(cdata, INA260_REG_MASKENABLE,&value))
            return -1;
        return sprintf(buf, "%d\n", (value>>12)&0x1);
    }else if (INA260_IS_ATTR(pol)){
        if(ina260_read_register(cdata, INA260_REG_MASKENABLE,&value))
            return -1;
        return sprintf(buf, "%d\n", (value>>11)&0x1);
    }else if (INA260_IS_ATTR(cnvr)){
        if(ina260_read_register(cdata, INA260_REG_MASKENABLE,&value))
            return -1;
        return sprintf(buf, "%d\n", (value>>10)&0x1);
    }else if (INA260_IS_ATTR(ovf)){
        if(ina260_read_register(cdata, INA260_REG_MASKENABLE,&value))
            return -1;
        return sprintf(buf, "%d\n", (value>>2)&0x1);
    }else if (INA260_IS_ATTR(apol)){
        if(ina260_read_register(cdata, INA260_REG_MASKENABLE,&value))
            return -1;
        return sprintf(buf, "%d\n", (value>>1)&0x1);
    }else if (INA260_IS_ATTR(len)){
        if(ina260_read_register(cdata, INA260_REG_MASKENABLE,&value))
            return -1;
        return sprintf(buf, "%d\n", value&0x1);
    }else if (INA260_IS_ATTR(did)){
        if(ina260_read_register(cdata, INA260_REG_DIE,&value))
            return -1;
        return sprintf(buf, "0x%x\n", (value>>4));
    }else if (INA260_IS_ATTR(rid)){
        if(ina260_read_register(cdata, INA260_REG_DIE,&value))
            return -1;
        return sprintf(buf, "0x%x\n", value&0x7);
    }else if (INA260_IS_ATTR(reset)){
        return sprintf(buf, "0\n");
    }
    return 0;
}

static int ina260_write_field3(struct client_data *cdata, unsigned char reg, unsigned char n, int value3bits){
    int mask, value;
    if(!(value3bits>=0 && value3bits <8))
        return -EINVAL;
    // Fetch register value:
    if(ina260_read_register(cdata,reg,&value))
        return 1;
    // Write bits:
    mask=~(0x7 << n);
    value &= mask; // clear bits
    value |= value3bits << n;
    // Write register value:
    if(ina260_write_register(cdata,reg,value))
        return 1;
    return 0;
}

static int ina260_write_field1(struct client_data *cdata, unsigned char reg, unsigned char n, int bit){
    int mask, value;
    if(!(bit==0 || bit == 1))
        return -EINVAL;
    // Fetch register value:
    if(ina260_read_register(cdata,reg,&value))
        return 1;
    // Set bit:
    mask=~(1<< n);
    value &= mask; // clear bit
    value |= bit << n;
    // Write register value
    if(ina260_write_register(cdata,reg,value))
        return 1;
    return 0;
}

static ssize_t attr_field_store(struct kobject *_kobj, 
                       struct kobj_attribute *attr,
               const char *buf, size_t count)
{
    struct client_data *cdata=container_of(_kobj,struct client_data,kobj);
    int data=0, ret=count;
    unsigned char reg=INA260_REG_CONFIGURATION;
    // Extract user supplied value
    if(kstrtoint(buf, 10,&data))
        return -EINVAL;
    // Store:
    if(INA260_IS_ATTR(reset) && data!=0){
        ret=ina260_write_register(cdata, reg, 0xFFFF);
    } else if(INA260_IS_ATTR(avg)){
      ret=ina260_write_field3(cdata,reg,9,data);
    } else if(INA260_IS_ATTR(mode)){
      ret=ina260_write_field3(cdata,reg,0,data);
    } else if(INA260_IS_ATTR(ishct)){
      ret=ina260_write_field3(cdata,reg,3,data);
    } else if(INA260_IS_ATTR(vbusct)){
      ret=ina260_write_field3(cdata,reg,6,data);
    } else if(INA260_IS_ATTR(ocl)){
      ret=ina260_write_field1(cdata,reg,15,data);
    } else if(INA260_IS_ATTR(ucl)){
      ret=ina260_write_field1(cdata,reg,14,data);
    } else if(INA260_IS_ATTR(bol)){
      ret=ina260_write_field1(cdata,reg,13,data);
    } else if(INA260_IS_ATTR(bul)){
      ret=ina260_write_field1(cdata,reg,12,data);
    } else if(INA260_IS_ATTR(pol)){
      ret=ina260_write_field1(cdata,reg,11,data);
    } else if(INA260_IS_ATTR(cnvr)){
      ret=ina260_write_field1(cdata,reg,10,data);
    } else if(INA260_IS_ATTR(apol)){
      ret=ina260_write_field1(cdata,reg,1,data);
    } else if(INA260_IS_ATTR(len)){
      ret=ina260_write_field1(cdata,reg,0,data);
    }
    return ret ? ret: count;
}


// ----- Registers -----
static struct kobj_attribute configuration_attribute =
    __ATTR(configuration, 0664, attr_show, attr_store);
static struct kobj_attribute current_attribute = {
	.attr = {.name = "current", // current is a defined macro so need to do it manually
		 .mode = VERIFY_OCTAL_PERMISSIONS(0444) },
	.show	= attr_show,
	.store	= attr_store,
};
static struct kobj_attribute bus_voltage_attribute =
    __ATTR(bus_voltage, 0444, attr_show, attr_store);
static struct kobj_attribute power_attribute =
    __ATTR(power, 0444, attr_show, attr_store);
static struct kobj_attribute mask_enable_attribute =
    __ATTR(mask_enable, 0664, attr_show, attr_store);
static struct kobj_attribute alert_limit_attribute =
    __ATTR(alert_limit, 0664, attr_show, attr_store);
static struct kobj_attribute manufacturer_id_attribute =
    __ATTR(manufacturer_id, 0664, attr_show, attr_store);
static struct kobj_attribute die_id_attribute=
    __ATTR(die_id, 0664, attr_show, attr_store);
static struct attribute *registers_attrs[] = {
    &configuration_attribute.attr,
    &current_attribute.attr,
    &bus_voltage_attribute.attr,
    &power_attribute.attr,
    &mask_enable_attribute.attr,
    &alert_limit_attribute.attr,
    &manufacturer_id_attribute.attr,
    &die_id_attribute.attr,
    NULL,   
};
static const struct attribute_group registers_group = {
	.attrs = registers_attrs,
    .name = "registers"
};

// ----- Fields -----
static struct kobj_attribute reset_field_attribute =
    __ATTR(reset, 0664, attr_field_show, attr_field_store);
static struct kobj_attribute avg_field_attribute =
    __ATTR(avg, 0664, attr_field_show, attr_field_store);
static struct kobj_attribute mode_field_attribute =
    __ATTR(mode, 0664, attr_field_show, attr_field_store);
static struct kobj_attribute ishct_field_attribute =
    __ATTR(ishct, 0664, attr_field_show, attr_field_store);
static struct kobj_attribute vbusct_field_attribute =
    __ATTR(vbusct, 0664, attr_field_show, attr_field_store);
static struct kobj_attribute aff_field_attribute =
    __ATTR(aff, 0444, attr_field_show, attr_field_store);
static struct kobj_attribute cvrf_field_attribute =
    __ATTR(cvrf, 0444, attr_field_show, attr_field_store);
static struct kobj_attribute ocl_field_attribute =
    __ATTR(ocl, 0664, attr_field_show, attr_field_store);
static struct kobj_attribute ucl_field_attribute =
    __ATTR(ucl, 0664, attr_field_show, attr_field_store);
static struct kobj_attribute bol_field_attribute =
    __ATTR(bol, 0664, attr_field_show, attr_field_store);
static struct kobj_attribute bul_field_attribute =
    __ATTR(bul, 0664, attr_field_show, attr_field_store);
static struct kobj_attribute pol_field_attribute =
    __ATTR(pol, 0664, attr_field_show, attr_field_store);
static struct kobj_attribute cnvr_field_attribute =
    __ATTR(cnvr, 0664, attr_field_show, attr_field_store);
static struct kobj_attribute ovf_field_attribute =
    __ATTR(ovf, 0444, attr_field_show, attr_field_store);
static struct kobj_attribute apol_field_attribute =
    __ATTR(apol, 0664, attr_field_show, attr_field_store);
static struct kobj_attribute len_field_attribute =
    __ATTR(len, 0664, attr_field_show, attr_field_store);
static struct kobj_attribute did_field_attribute =
    __ATTR(did, 0444, attr_field_show, attr_field_store);
static struct kobj_attribute rid_field_attribute =
    __ATTR(rid, 0444, attr_field_show, attr_field_store); 
static struct attribute *fields_attrs[] = {
    &reset_field_attribute.attr,
    &avg_field_attribute.attr,
    &mode_field_attribute.attr,
    &ishct_field_attribute.attr,
    &vbusct_field_attribute.attr,
    &aff_field_attribute.attr,
    &cvrf_field_attribute.attr,
    &ocl_field_attribute.attr,
    &ucl_field_attribute.attr,
    &bol_field_attribute.attr,
    &bul_field_attribute.attr,
    &pol_field_attribute.attr,
    &cnvr_field_attribute.attr,
    &ovf_field_attribute.attr,
    &apol_field_attribute.attr,
    &len_field_attribute.attr,
    &did_field_attribute.attr,
    &rid_field_attribute.attr,
    NULL,   
};
static const struct attribute_group fields_group = {
	.attrs = fields_attrs,
};


static struct kobj_type ina260_ktype = {
	.sysfs_ops	= &kobj_sysfs_ops,
};

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;
}

static int ina260_probe_new(struct i2c_client *client){
    struct client_data *p;
    if(ina260_probe_register(client,INA260_REG_MANUFACTURER,0x5449) ||
       ina260_probe_register(client,INA260_REG_DIE,0x2270)){
        printk("INA260 chip probe failed on i2c bus %d\n",client->adapter->nr);
        return 1;
    }
    printk("New INA260 chip addr=0x%x detected on i2c bus %d\n",client->addr,client->adapter->nr);
    p=kzalloc(sizeof(struct client_data),GFP_KERNEL);
    kobject_init(&p->kobj,&ina260_ktype);
    if(kobject_add(&p->kobj,ina260_kobj,client->dev.kobj.name)){
        kobject_put(&p->kobj);
        kfree(p);
        return 1;
    }
    p->client=client;
    p->reg=INA260_REG_DIE; // Last reg to be used
    i2c_set_clientdata(client,p);
    if(sysfs_create_group(&p->kobj,&registers_group)||
       sysfs_create_group(&p->kobj,&fields_group)){
        kobject_put(&p->kobj);
        kfree(p);
        return 1;
    }
    return 0;
}

static void ina260_remove(struct i2c_client *client){
    struct client_data *p=i2c_get_clientdata(client);
    kobject_put(&p->kobj);
    kfree(p);
    printk("INA260 addr=0x%x remove from i2c bus %d\n",client->addr,client->adapter->nr);
}

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

static int __init ina260_init(void){
    ina260_kobj = kobject_create_and_add("ina260",kernel_kobj);
    i2c_add_driver(&ina260_driver);
    return 0;
}

static void __exit ina260_exit(void){
    i2c_del_driver(&ina260_driver);
    kobject_put(ina260_kobj);
}

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