#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/hwmon.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/property.h>
#include <linux/regmap.h>
#include <linux/regulator/consumer.h>
#define LTC2991_STATUS_LOW 0x00
#define LTC2991_CH_EN_TRIGGER 0x01
#define LTC2991_V1_V4_CTRL 0x06
#define LTC2991_V5_V8_CTRL 0x07
#define LTC2991_PWM_TH_LSB_T_INT 0x08
#define LTC2991_PWM_TH_MSB 0x09
#define LTC2991_CHANNEL_V_MSB(x) (0x0A + ((x) * 2))
#define LTC2991_CHANNEL_T_MSB(x) (0x0A + ((x) * 4))
#define LTC2991_CHANNEL_C_MSB(x) (0x0C + ((x) * 4))
#define LTC2991_T_INT_MSB 0x1A
#define LTC2991_VCC_MSB 0x1C
#define LTC2991_V7_V8_EN BIT(7)
#define LTC2991_V5_V6_EN BIT(6)
#define LTC2991_V3_V4_EN BIT(5)
#define LTC2991_V1_V2_EN BIT(4)
#define LTC2991_T_INT_VCC_EN BIT(3)
#define LTC2991_V3_V4_FILT_EN BIT(7)
#define LTC2991_V3_V4_TEMP_EN BIT(5)
#define LTC2991_V3_V4_DIFF_EN BIT(4)
#define LTC2991_V1_V2_FILT_EN BIT(3)
#define LTC2991_V1_V2_TEMP_EN BIT(1)
#define LTC2991_V1_V2_DIFF_EN BIT(0)
#define LTC2991_V7_V8_FILT_EN BIT(7)
#define LTC2991_V7_V8_TEMP_EN BIT(5)
#define LTC2991_V7_V8_DIFF_EN BIT(4)
#define LTC2991_V5_V6_FILT_EN BIT(3)
#define LTC2991_V5_V6_TEMP_EN BIT(1)
#define LTC2991_V5_V6_DIFF_EN BIT(0)
#define LTC2991_REPEAT_ACQ_EN BIT(4)
#define LTC2991_T_INT_FILT_EN BIT(3)
#define LTC2991_MAX_CHANNEL 4
#define LTC2991_T_INT_CH_NR 4
#define LTC2991_VCC_CH_NR 0
struct ltc2991_state {
struct regmap *regmap;
u32 r_sense_uohm[LTC2991_MAX_CHANNEL];
bool temp_en[LTC2991_MAX_CHANNEL];
};
static int ltc2991_read_reg(struct ltc2991_state *st, u8 addr, u8 reg_len,
int *val)
{
__be16 regvals;
int ret;
if (reg_len < 2)
return regmap_read(st->regmap, addr, val);
ret = regmap_bulk_read(st->regmap, addr, ®vals, reg_len);
if (ret)
return ret;
*val = be16_to_cpu(regvals);
return 0;
}
static int ltc2991_get_voltage(struct ltc2991_state *st, u32 reg, long *val)
{
int reg_val, ret, offset = 0;
ret = ltc2991_read_reg(st, reg, 2, ®_val);
if (ret)
return ret;
if (reg == LTC2991_VCC_MSB)
offset = 2500;
*val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 14) * 30518,
1000 * 100) + offset;
return 0;
}
static int ltc2991_read_in(struct device *dev, u32 attr, int channel, long *val)
{
struct ltc2991_state *st = dev_get_drvdata(dev);
u32 reg;
switch (attr) {
case hwmon_in_input:
if (channel == LTC2991_VCC_CH_NR)
reg = LTC2991_VCC_MSB;
else
reg = LTC2991_CHANNEL_V_MSB(channel - 1);
return ltc2991_get_voltage(st, reg, val);
default:
return -EOPNOTSUPP;
}
}
static int ltc2991_get_curr(struct ltc2991_state *st, u32 reg, int channel,
long *val)
{
int reg_val, ret;
ret = ltc2991_read_reg(st, reg, 2, ®_val);
if (ret)
return ret;
*val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 14) * 19075,
(s32)st->r_sense_uohm[channel]);
return 0;
}
static int ltc2991_read_curr(struct device *dev, u32 attr, int channel,
long *val)
{
struct ltc2991_state *st = dev_get_drvdata(dev);
u32 reg;
switch (attr) {
case hwmon_curr_input:
reg = LTC2991_CHANNEL_C_MSB(channel);
return ltc2991_get_curr(st, reg, channel, val);
default:
return -EOPNOTSUPP;
}
}
static int ltc2991_get_temp(struct ltc2991_state *st, u32 reg, int channel,
long *val)
{
int reg_val, ret;
ret = ltc2991_read_reg(st, reg, 2, ®_val);
if (ret)
return ret;
*val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 12) * 1000, 16);
return 0;
}
static int ltc2991_read_temp(struct device *dev, u32 attr, int channel,
long *val)
{
struct ltc2991_state *st = dev_get_drvdata(dev);
u32 reg;
switch (attr) {
case hwmon_temp_input:
if (channel == LTC2991_T_INT_CH_NR)
reg = LTC2991_T_INT_MSB;
else
reg = LTC2991_CHANNEL_T_MSB(channel);
return ltc2991_get_temp(st, reg, channel, val);
default:
return -EOPNOTSUPP;
}
}
static int ltc2991_read(struct device *dev, enum hwmon_sensor_types type,
u32 attr, int channel, long *val)
{
switch (type) {
case hwmon_in:
return ltc2991_read_in(dev, attr, channel, val);
case hwmon_curr:
return ltc2991_read_curr(dev, attr, channel, val);
case hwmon_temp:
return ltc2991_read_temp(dev, attr, channel, val);
default:
return -EOPNOTSUPP;
}
}
static umode_t ltc2991_is_visible(const void *data,
enum hwmon_sensor_types type, u32 attr,
int channel)
{
const struct ltc2991_state *st = data;
switch (type) {
case hwmon_in:
switch (attr) {
case hwmon_in_input:
if (channel == LTC2991_VCC_CH_NR)
return 0444;
if (st->temp_en[(channel - 1) / 2])
break;
if (channel % 2)
return 0444;
if (!st->r_sense_uohm[(channel - 1) / 2])
return 0444;
}
break;
case hwmon_curr:
switch (attr) {
case hwmon_curr_input:
if (st->r_sense_uohm[channel])
return 0444;
break;
}
break;
case hwmon_temp:
switch (attr) {
case hwmon_temp_input:
if (channel == LTC2991_T_INT_CH_NR ||
st->temp_en[channel])
return 0444;
break;
}
break;
default:
break;
}
return 0;
}
static const struct hwmon_ops ltc2991_hwmon_ops = {
.is_visible = ltc2991_is_visible,
.read = ltc2991_read,
};
static const struct hwmon_channel_info *ltc2991_info[] = {
HWMON_CHANNEL_INFO(temp,
HWMON_T_INPUT,
HWMON_T_INPUT,
HWMON_T_INPUT,
HWMON_T_INPUT,
HWMON_T_INPUT
),
HWMON_CHANNEL_INFO(curr,
HWMON_C_INPUT,
HWMON_C_INPUT,
HWMON_C_INPUT,
HWMON_C_INPUT
),
HWMON_CHANNEL_INFO(in,
HWMON_I_INPUT,
HWMON_I_INPUT,
HWMON_I_INPUT,
HWMON_I_INPUT,
HWMON_I_INPUT,
HWMON_I_INPUT,
HWMON_I_INPUT,
HWMON_I_INPUT,
HWMON_I_INPUT
),
NULL
};
static const struct hwmon_chip_info ltc2991_chip_info = {
.ops = <c2991_hwmon_ops,
.info = ltc2991_info,
};
static const struct regmap_config ltc2991_regmap_config = {
.reg_bits = 8,
.val_bits = 8,
.max_register = 0x1D,
};
static int ltc2991_init(struct ltc2991_state *st, struct device *dev)
{
int ret;
u32 val, addr;
u8 v5_v8_reg_data = 0, v1_v4_reg_data = 0;
ret = devm_regulator_get_enable(dev, "vcc");
if (ret)
return dev_err_probe(dev, ret,
"failed to enable regulator\n");
device_for_each_child_node_scoped(dev, child) {
ret = fwnode_property_read_u32(child, "reg", &addr);
if (ret < 0)
return ret;
if (addr > 3)
return -EINVAL;
ret = fwnode_property_read_u32(child,
"shunt-resistor-micro-ohms",
&val);
if (!ret) {
if (!val)
return dev_err_probe(dev, -EINVAL,
"shunt resistor value cannot be zero\n");
st->r_sense_uohm[addr] = val;
switch (addr) {
case 0:
v1_v4_reg_data |= LTC2991_V1_V2_DIFF_EN;
break;
case 1:
v1_v4_reg_data |= LTC2991_V3_V4_DIFF_EN;
break;
case 2:
v5_v8_reg_data |= LTC2991_V5_V6_DIFF_EN;
break;
case 3:
v5_v8_reg_data |= LTC2991_V7_V8_DIFF_EN;
break;
default:
break;
}
}
ret = fwnode_property_read_bool(child,
"adi,temperature-enable");
if (ret) {
st->temp_en[addr] = ret;
switch (addr) {
case 0:
v1_v4_reg_data |= LTC2991_V1_V2_TEMP_EN;
break;
case 1:
v1_v4_reg_data |= LTC2991_V3_V4_TEMP_EN;
break;
case 2:
v5_v8_reg_data |= LTC2991_V5_V6_TEMP_EN;
break;
case 3:
v5_v8_reg_data |= LTC2991_V7_V8_TEMP_EN;
break;
default:
break;
}
}
}
ret = regmap_write(st->regmap, LTC2991_V5_V8_CTRL, v5_v8_reg_data);
if (ret)
return dev_err_probe(dev, ret,
"Error: Failed to set V5-V8 CTRL reg.\n");
ret = regmap_write(st->regmap, LTC2991_V1_V4_CTRL, v1_v4_reg_data);
if (ret)
return dev_err_probe(dev, ret,
"Error: Failed to set V1-V4 CTRL reg.\n");
ret = regmap_write(st->regmap, LTC2991_PWM_TH_LSB_T_INT,
LTC2991_REPEAT_ACQ_EN);
if (ret)
return dev_err_probe(dev, ret,
"Error: Failed to set continuous mode.\n");
return regmap_write(st->regmap, LTC2991_CH_EN_TRIGGER,
LTC2991_V7_V8_EN | LTC2991_V5_V6_EN |
LTC2991_V3_V4_EN | LTC2991_V1_V2_EN |
LTC2991_T_INT_VCC_EN);
}
static int ltc2991_i2c_probe(struct i2c_client *client)
{
int ret;
struct device *hwmon_dev;
struct ltc2991_state *st;
st = devm_kzalloc(&client->dev, sizeof(*st), GFP_KERNEL);
if (!st)
return -ENOMEM;
st->regmap = devm_regmap_init_i2c(client, <c2991_regmap_config);
if (IS_ERR(st->regmap))
return PTR_ERR(st->regmap);
ret = ltc2991_init(st, &client->dev);
if (ret)
return ret;
hwmon_dev = devm_hwmon_device_register_with_info(&client->dev,
client->name, st,
<c2991_chip_info,
NULL);
return PTR_ERR_OR_ZERO(hwmon_dev);
}
static const struct of_device_id ltc2991_of_match[] = {
{ .compatible = "adi,ltc2991" },
{ }
};
MODULE_DEVICE_TABLE(of, ltc2991_of_match);
static const struct i2c_device_id ltc2991_i2c_id[] = {
{ "ltc2991" },
{}
};
MODULE_DEVICE_TABLE(i2c, ltc2991_i2c_id);
static struct i2c_driver ltc2991_i2c_driver = {
.driver = {
.name = "ltc2991",
.of_match_table = ltc2991_of_match,
},
.probe = ltc2991_i2c_probe,
.id_table = ltc2991_i2c_id,
};
module_i2c_driver(ltc2991_i2c_driver);
MODULE_AUTHOR("Antoniu Miclaus <antoniu.miclaus@analog.com>");
MODULE_DESCRIPTION("Analog Devices LTC2991 HWMON Driver");
MODULE_LICENSE("GPL");
