[Feature]add MT2731_MP2_MR2_SVN388 baseline version
Change-Id: Ief04314834b31e27effab435d3ca8ba33b499059
diff --git a/src/kernel/linux/v4.14/drivers/hwmon/ltc4215.c b/src/kernel/linux/v4.14/drivers/hwmon/ltc4215.c
new file mode 100644
index 0000000..c8a9bd9
--- /dev/null
+++ b/src/kernel/linux/v4.14/drivers/hwmon/ltc4215.c
@@ -0,0 +1,280 @@
+/*
+ * Driver for Linear Technology LTC4215 I2C Hot Swap Controller
+ *
+ * Copyright (C) 2009 Ira W. Snyder <iws@ovro.caltech.edu>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * Datasheet:
+ * http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1003,C1006,C1163,P17572,D12697
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/jiffies.h>
+
+/* Here are names of the chip's registers (a.k.a. commands) */
+enum ltc4215_cmd {
+ LTC4215_CONTROL = 0x00, /* rw */
+ LTC4215_ALERT = 0x01, /* rw */
+ LTC4215_STATUS = 0x02, /* ro */
+ LTC4215_FAULT = 0x03, /* rw */
+ LTC4215_SENSE = 0x04, /* rw */
+ LTC4215_SOURCE = 0x05, /* rw */
+ LTC4215_ADIN = 0x06, /* rw */
+};
+
+struct ltc4215_data {
+ struct i2c_client *client;
+
+ struct mutex update_lock;
+ bool valid;
+ unsigned long last_updated; /* in jiffies */
+
+ /* Registers */
+ u8 regs[7];
+};
+
+static struct ltc4215_data *ltc4215_update_device(struct device *dev)
+{
+ struct ltc4215_data *data = dev_get_drvdata(dev);
+ struct i2c_client *client = data->client;
+ s32 val;
+ int i;
+
+ mutex_lock(&data->update_lock);
+
+ /* The chip's A/D updates 10 times per second */
+ if (time_after(jiffies, data->last_updated + HZ / 10) || !data->valid) {
+
+ dev_dbg(&client->dev, "Starting ltc4215 update\n");
+
+ /* Read all registers */
+ for (i = 0; i < ARRAY_SIZE(data->regs); i++) {
+ val = i2c_smbus_read_byte_data(client, i);
+ if (unlikely(val < 0))
+ data->regs[i] = 0;
+ else
+ data->regs[i] = val;
+ }
+
+ data->last_updated = jiffies;
+ data->valid = 1;
+ }
+
+ mutex_unlock(&data->update_lock);
+
+ return data;
+}
+
+/* Return the voltage from the given register in millivolts */
+static int ltc4215_get_voltage(struct device *dev, u8 reg)
+{
+ struct ltc4215_data *data = ltc4215_update_device(dev);
+ const u8 regval = data->regs[reg];
+ u32 voltage = 0;
+
+ switch (reg) {
+ case LTC4215_SENSE:
+ /* 151 uV per increment */
+ voltage = regval * 151 / 1000;
+ break;
+ case LTC4215_SOURCE:
+ /* 60.5 mV per increment */
+ voltage = regval * 605 / 10;
+ break;
+ case LTC4215_ADIN:
+ /*
+ * The ADIN input is divided by 12.5, and has 4.82 mV
+ * per increment, so we have the additional multiply
+ */
+ voltage = regval * 482 * 125 / 1000;
+ break;
+ default:
+ /* If we get here, the developer messed up */
+ WARN_ON_ONCE(1);
+ break;
+ }
+
+ return voltage;
+}
+
+/* Return the current from the sense resistor in mA */
+static unsigned int ltc4215_get_current(struct device *dev)
+{
+ struct ltc4215_data *data = ltc4215_update_device(dev);
+
+ /*
+ * The strange looking conversions that follow are fixed-point
+ * math, since we cannot do floating point in the kernel.
+ *
+ * Step 1: convert sense register to microVolts
+ * Step 2: convert voltage to milliAmperes
+ *
+ * If you play around with the V=IR equation, you come up with
+ * the following: X uV / Y mOhm == Z mA
+ *
+ * With the resistors that are fractions of a milliOhm, we multiply
+ * the voltage and resistance by 10, to shift the decimal point.
+ * Now we can use the normal division operator again.
+ */
+
+ /* Calculate voltage in microVolts (151 uV per increment) */
+ const unsigned int voltage = data->regs[LTC4215_SENSE] * 151;
+
+ /* Calculate current in milliAmperes (4 milliOhm sense resistor) */
+ const unsigned int curr = voltage / 4;
+
+ return curr;
+}
+
+static ssize_t ltc4215_show_voltage(struct device *dev,
+ struct device_attribute *da,
+ char *buf)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+ const int voltage = ltc4215_get_voltage(dev, attr->index);
+
+ return snprintf(buf, PAGE_SIZE, "%d\n", voltage);
+}
+
+static ssize_t ltc4215_show_current(struct device *dev,
+ struct device_attribute *da,
+ char *buf)
+{
+ const unsigned int curr = ltc4215_get_current(dev);
+
+ return snprintf(buf, PAGE_SIZE, "%u\n", curr);
+}
+
+static ssize_t ltc4215_show_power(struct device *dev,
+ struct device_attribute *da,
+ char *buf)
+{
+ const unsigned int curr = ltc4215_get_current(dev);
+ const int output_voltage = ltc4215_get_voltage(dev, LTC4215_ADIN);
+
+ /* current in mA * voltage in mV == power in uW */
+ const unsigned int power = abs(output_voltage * curr);
+
+ return snprintf(buf, PAGE_SIZE, "%u\n", power);
+}
+
+static ssize_t ltc4215_show_alarm(struct device *dev,
+ struct device_attribute *da,
+ char *buf)
+{
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
+ struct ltc4215_data *data = ltc4215_update_device(dev);
+ const u8 reg = data->regs[LTC4215_STATUS];
+ const u32 mask = attr->index;
+
+ return snprintf(buf, PAGE_SIZE, "%u\n", !!(reg & mask));
+}
+
+/*
+ * These macros are used below in constructing device attribute objects
+ * for use with sysfs_create_group() to make a sysfs device file
+ * for each register.
+ */
+
+/* Construct a sensor_device_attribute structure for each register */
+
+/* Current */
+static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc4215_show_current, NULL, 0);
+static SENSOR_DEVICE_ATTR(curr1_max_alarm, S_IRUGO, ltc4215_show_alarm, NULL,
+ 1 << 2);
+
+/* Power (virtual) */
+static SENSOR_DEVICE_ATTR(power1_input, S_IRUGO, ltc4215_show_power, NULL, 0);
+
+/* Input Voltage */
+static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ltc4215_show_voltage, NULL,
+ LTC4215_ADIN);
+static SENSOR_DEVICE_ATTR(in1_max_alarm, S_IRUGO, ltc4215_show_alarm, NULL,
+ 1 << 0);
+static SENSOR_DEVICE_ATTR(in1_min_alarm, S_IRUGO, ltc4215_show_alarm, NULL,
+ 1 << 1);
+
+/* Output Voltage */
+static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ltc4215_show_voltage, NULL,
+ LTC4215_SOURCE);
+static SENSOR_DEVICE_ATTR(in2_min_alarm, S_IRUGO, ltc4215_show_alarm, NULL,
+ 1 << 3);
+
+/*
+ * Finally, construct an array of pointers to members of the above objects,
+ * as required for sysfs_create_group()
+ */
+static struct attribute *ltc4215_attrs[] = {
+ &sensor_dev_attr_curr1_input.dev_attr.attr,
+ &sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
+
+ &sensor_dev_attr_power1_input.dev_attr.attr,
+
+ &sensor_dev_attr_in1_input.dev_attr.attr,
+ &sensor_dev_attr_in1_max_alarm.dev_attr.attr,
+ &sensor_dev_attr_in1_min_alarm.dev_attr.attr,
+
+ &sensor_dev_attr_in2_input.dev_attr.attr,
+ &sensor_dev_attr_in2_min_alarm.dev_attr.attr,
+
+ NULL,
+};
+ATTRIBUTE_GROUPS(ltc4215);
+
+static int ltc4215_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ struct i2c_adapter *adapter = client->adapter;
+ struct device *dev = &client->dev;
+ struct ltc4215_data *data;
+ struct device *hwmon_dev;
+
+ if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
+ return -ENODEV;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->client = client;
+ mutex_init(&data->update_lock);
+
+ /* Initialize the LTC4215 chip */
+ i2c_smbus_write_byte_data(client, LTC4215_FAULT, 0x00);
+
+ hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
+ data,
+ ltc4215_groups);
+ return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct i2c_device_id ltc4215_id[] = {
+ { "ltc4215", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, ltc4215_id);
+
+/* This is the driver that will be inserted */
+static struct i2c_driver ltc4215_driver = {
+ .driver = {
+ .name = "ltc4215",
+ },
+ .probe = ltc4215_probe,
+ .id_table = ltc4215_id,
+};
+
+module_i2c_driver(ltc4215_driver);
+
+MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
+MODULE_DESCRIPTION("LTC4215 driver");
+MODULE_LICENSE("GPL");