drivers: power: ltc7841: Add README for LTC7841

Add README.rst documentation file for LTC7841 alongside other
documentation related files.

Signed-off-by: Marvin Neil Cabuenas <[email protected]>

doc/sphinx/source/drivers/ltc7841.rst

@@ -0,0 +1 @@
+.. include:: ../../../../drivers/power/ltc7841/README.rst

doc/sphinx/source/drivers_doc.rst

@@ -101,6 +101,7 @@ POWER MANAGEMENT
    drivers/ltc2992
    drivers/ltc4162l
    drivers/ltc4296
+   drivers/ltc7841
    drivers/ltm4686
    drivers/lt7170
    drivers/lt7182s

drivers/power/ltc7841/README.rst

@@ -0,0 +1,169 @@
+LTC7841 no-OS driver
+====================
+
+Supported Devices
+-----------------
+
+`LTC7841 <https://www.analog.com/LTC7841>`_
+
+Overview
+--------
+
+The LTC7841 is a high performance PolyPhase single output synchronous boost converter
+controller that drives two N-channel power MOSFET stages out-of-phase. Multiphase operation
+reduces input and output capacitor requirements and allows the use of smaller inductors than the
+single-phase equivalent. Synchronous rectification increases efficiency, reduces power loss and
+eases thermal requirements, enabling high power boost applications. The output voltage can be
+adjusted up to 60V with 0.2% resolution via a PMBUS-compliant serial interface. The serial interface
+can also be used to read back fault status, input/output current, input/output voltage and
+temperature.
+
+Applications
+------------
+
+LTC7841
+-------
+
+* Automotive Systems, Medical, Industrial
+
+LTC7841 Device Configuration
+-----------------------------
+
+Driver Initialization
+---------------------
+
+In order to be able to use the device, you will have to provide the support
+for the communication protocol (I2C).
+
+The first API to be called is **ltc7841_init**. Make sure that it returns 0,
+which means that the driver was initialized correctly.
+
+Status Bytes
+------------
+
+Assertion in the status bytes/words indicates fault/warning in device input/
+output, temperature, and communication, memory and logic. These statuses can be
+accessed via the **ltc7841_read_status** API.
+
+Telemetry
+---------
+
+Measurements for each output channel can be read using the
+**ltc7841_read_value** API. Some telemetry values includes input/output voltage,
+input/output current and die temperature.
+
+VOUT Configuration
+------------------
+
+The LTC7841 output voltage is programmable from 0V to 48V. These can be
+configured using the **ltc7841_vout_value** API.
+
+LTC7841 Driver Initialization Example
+-------------------------------------
+
+.. code-block:: bash
+
+	struct ltc7841_desc *ltp8800_desc;
+
+	struct ltc7841_init_param ltc7841_ip = {
+		.comm_param = {
+		.device_id      = LTC7841_I2C_DEVICE_ID,
+		.max_speed_hz   = LTC7841_I2C_CLK_SPEED,
+		.slave_address  = LTC7841_I2C_ADDR,
+		.platform_ops   = &max_i2c_ops,
+		.extra          = (void *)&ltc7841_i2c_extra,
+	    },
+	    .regs = ltc7841_regs
+	};
+
+	ret = ltc7841_init(&ltp8800_desc, &ltc7841_ip);
+	if (ret)
+	{
+		goto error;
+	}
+
+LTC7841 no-OS IIO support
+-------------------------
+
+The LTC7841 IIO driver comes on top of the LTC7841 driver and offers support
+for interfacing IIO clients through libiio.
+
+LTC7841 IIO Device Configuration
+--------------------------------
+
+Channels
+--------
+
+The device has a total of 3 input channels and 2 output channels. The input
+consists of the input voltage, input current, and the forward diode
+temperature. The output consists of the output voltage and current.
+
+* ``vout - output voltage``
+* ``iout - output current``
+* ``vin - input voltage``
+* ``iin - input current``
+* ``temperature - forward diode temperature``
+
+Channel Attributes
+------------------
+
+Each channels has 1 channel attribute:
+
+* ``raw - the raw value of the channel``
+
+Global Attributes
+-----------------
+
+The device has a total of 1 global attribute:
+
+* ``vout_command - VOUT_COMMAND value of the channel output``
+
+Debug Attributes
+----------------
+
+The device has a total of 1 debug attribute:
+
+* ``status_word - Status word value``
+
+LTC7841 IIO Driver Initialization Example
+-----------------------------------------
+
+.. code-block:: bash
+
+	int ret;
+
+	struct ltc7841_iio_desc *ltc7841_iio_desc;
+	struct ltc7841_iio_desc_init_param ltc7841_iio_ip = 
+    {
+		.ltc7841_init_param = &ltc7841_ip,
+	};
+
+	struct iio_app_desc *app;
+	struct iio_app_init_param app_init_param = { 0 };
+
+	ret = ltc7841_iio_init(&ltc7841_iio_desc, &ltc7841_iio_ip);
+	if (ret)
+    {
+		goto exit;
+    }
+
+	struct iio_app_device iio_devices[] = 
+    {
+		{
+			.name = "ltc7841",
+			.dev = ltc7841_iio_desc,
+			.dev_descriptor = ltc7841_iio_desc->iio_dev,
+		}
+	};
+
+	app_init_param.devices = iio_devices;
+	app_init_param.nb_devices = NO_OS_ARRAY_SIZE(iio_devices);
+	app_init_param.uart_init_params = uart_ip;
+
+	ret = iio_app_init(&app, app_init_param);
+	if (ret)
+	{
+		return ret;
+	}
+
+	return iio_app_run(app);