--- /dev/null
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2023 Analog Devices, Inc.
+ * Author: Antoniu Miclaus <antoniu.miclaus@analog.com>
+ */
+
+#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(7)
+#define LTC2991_V5_V6_TEMP_EN BIT(5)
+#define LTC2991_V5_V6_DIFF_EN BIT(4)
+
+#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 device *dev;
+ 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)
+ /* Vcc 2.5V offset */
+ offset = 2500;
+
+ /* Vx, 305.18uV/LSB */
+ *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;
+
+ /* Vx-Vy, 19.075uV/LSB */
+ *val = DIV_ROUND_CLOSEST(sign_extend32(reg_val, 14) * 19075,
+ 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;
+
+ /* Temp LSB = 0.0625 Degrees */
+ *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 (st->temp_en[channel] ||
+ channel == LTC2991_T_INT_CH_NR)
+ 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 fwnode_handle *child;
+ int ret;
+ u32 val, addr;
+ u8 v5_v8_reg_data = 0, v1_v4_reg_data = 0;
+
+ ret = devm_regulator_get_enable(st->dev, "vcc");
+ if (ret)
+ return dev_err_probe(st->dev, ret,
+ "failed to enable regulator\n");
+
+ device_for_each_child_node(st->dev, child) {
+ ret = fwnode_property_read_u32(child, "reg", &addr);
+ if (ret < 0) {
+ fwnode_handle_put(child);
+ return ret;
+ }
+
+ if (addr > 3) {
+ fwnode_handle_put(child);
+ return -EINVAL;
+ }
+
+ ret = fwnode_property_read_u32(child,
+ "shunt-resistor-micro-ohms",
+ &val);
+ if (!ret) {
+ if (!val)
+ return dev_err_probe(st->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(st->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(st->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(st->dev, ret,
+ "Error: Failed to set contiuous mode.\n");
+
+ /* Enable all channels and trigger conversions */
+ 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->dev = &client->dev;
+ st->regmap = devm_regmap_init_i2c(client, <c2991_regmap_config);
+ if (IS_ERR(st->regmap))
+ return PTR_ERR(st->regmap);
+
+ ret = ltc2991_init(st);
+ 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", 0 },
+ {}
+};
+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");
projects / users / jedix / linux-maple.git / commitdiff