Merge branch 'agust@denx.de' of git://git.denx.de/u-boot-staging

Documentation/devicetree/bindings/misc/gdsys,io-endpoint.txt

@@ -0,0 +1,20 @@
+gdsys IO endpoint of IHS FPGA devices
+
+The IO endpoint of IHS FPGA devices is a packet-based transmission interface
+that allows interconnected gdsys devices to send and receive data over the
+FPGA's main ethernet connection.
+
+Required properties:
+- compatible: must be "gdsys,io-endpoint"
+- reg: describes the address and length of the endpoint's register map (within
+  the FPGA's register space)
+
+Example:
+
+fpga0_ep0 {
+	compatible = "gdsys,io-endpoint";
+	reg = <0x020 0x10
+           0x320 0x10
+           0x340 0x10
+           0x360 0x10>;
+};

arch/sandbox/dts/test.dts

@@ -286,6 +286,10 @@
 		mbox-names = "other", "test";
 	};
 
+	misc-test {
+		compatible = "sandbox,misc_sandbox";
+	};
+
 	mmc2 {
 		compatible = "sandbox,mmc";
 	};

drivers/misc/Kconfig

@@ -277,4 +277,10 @@ config GDSYS_RXAUI_CTRL
 	depends on MISC
 	help
 	  Support gdsys FPGA's RXAUI control.
+
+config GDSYS_IOEP
+	bool "Enable gdsys IOEP driver"
+	depends on MISC
+	help
+	  Support gdsys FPGA's IO endpoint driver.
 endmenu

drivers/misc/Makefile

@@ -39,7 +39,7 @@ ifdef CONFIG_SPL_BUILD
 obj-$(CONFIG_SANDBOX) += spltest_sandbox.o
 endif
 endif
-obj-$(CONFIG_SANDBOX) += syscon_sandbox.o
+obj-$(CONFIG_SANDBOX) += syscon_sandbox.o misc_sandbox.o
 obj-$(CONFIG_TEGRA_CAR) += tegra_car.o
 obj-$(CONFIG_TEGRA186_BPMP) += tegra186_bpmp.o
 obj-$(CONFIG_TWL4030_LED) += twl4030_led.o
@@ -53,4 +53,5 @@ obj-$(CONFIG_ROCKCHIP_EFUSE) += rockchip-efuse.o
 obj-$(CONFIG_STM32_RCC) += stm32_rcc.o
 obj-$(CONFIG_STM32MP_FUSE) += stm32mp_fuse.o
 obj-$(CONFIG_SYS_DPAA_QBMAN) += fsl_portals.o
+obj-$(CONFIG_GDSYS_IOEP) += gdsys_ioep.o
 obj-$(CONFIG_GDSYS_RXAUI_CTRL) += gdsys_rxaui_ctrl.o

drivers/misc/gdsys_ioep.c

@@ -0,0 +1,209 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2017
+ * Mario Six,  Guntermann & Drunck GmbH, mario.six@gdsys.cc
+ *
+ * based on the cmd_ioloop driver/command, which is
+ *
+ * (C) Copyright 2014
+ * Dirk Eibach, Guntermann & Drunck GmbH, dirk.eibach@gdsys.cc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <misc.h>
+#include <regmap.h>
+
+#include "gdsys_ioep.h"
+
+/**
+ * struct gdsys_ioep_priv - Private data structure for IOEP devices
+ * @map:   Register map to be used for the device
+ * @state: Flag to keep the current status of the RX control (enabled/disabled)
+ */
+struct gdsys_ioep_priv {
+	struct regmap *map;
+	bool state;
+};
+
+/**
+ * enum last_spec - Convenience enum for read data sanity check
+ * @READ_DATA_IS_LAST:     The data to be read should be the final data of the
+ *			   current packet
+ * @READ_DATA_IS_NOT_LAST: The data to be read should not be the final data of
+ *			   the current packet
+ */
+enum last_spec {
+	READ_DATA_IS_LAST,
+	READ_DATA_IS_NOT_LAST,
+};
+
+static int gdsys_ioep_set_receive(struct udevice *dev, bool val)
+{
+	struct gdsys_ioep_priv *priv = dev_get_priv(dev);
+	u16 state;
+
+	priv->state = !priv->state;
+
+	if (val)
+		state = CTRL_PROC_RECEIVE_ENABLE;
+	else
+		state = ~CTRL_PROC_RECEIVE_ENABLE;
+
+	gdsys_ioep_set(priv->map, tx_control, state);
+
+	if (val) {
+		/* Set device address to dummy 1 */
+		gdsys_ioep_set(priv->map, device_address, 1);
+	}
+
+	return !priv->state;
+}
+
+static int gdsys_ioep_send(struct udevice *dev, int offset,
+			   const void *buf, int size)
+{
+	struct gdsys_ioep_priv *priv = dev_get_priv(dev);
+	int k;
+	u16 *p = (u16 *)buf;
+
+	for (k = 0; k < size; ++k)
+		gdsys_ioep_set(priv->map, transmit_data, *(p++));
+
+	gdsys_ioep_set(priv->map, tx_control, CTRL_PROC_RECEIVE_ENABLE |
+					      CTRL_FLUSH_TRANSMIT_BUFFER);
+
+	return 0;
+}
+
+/**
+ * receive_byte_buffer() - Read data from a IOEP device
+ * @dev:       The IOEP device to read data from
+ * @len:       The length of the data to read
+ * @buffer:    The buffer to read the data into
+ * @last_spec: Flag to indicate if the data to be read in this call should be
+ *	       the final data of the current packet (i.e. it should be empty
+ *	       after this read)
+ *
+ * Return: 0 if OK, -ve on error
+ */
+static int receive_byte_buffer(struct udevice *dev, uint len,
+			       u16 *buffer, enum last_spec last_spec)
+{
+	struct gdsys_ioep_priv *priv = dev_get_priv(dev);
+	int k;
+	int ret = -EIO;
+
+	for (k = 0; k < len; ++k) {
+		u16 rx_tx_status;
+
+		gdsys_ioep_get(priv->map, receive_data, buffer++);
+
+		gdsys_ioep_get(priv->map, rx_tx_status, &rx_tx_status);
+		/*
+		 * Sanity check: If the data read should have been the last,
+		 * but wasn't, something is wrong
+		 */
+		if (k == (len - 1) && (last_spec == READ_DATA_IS_NOT_LAST ||
+				       rx_tx_status & STATE_RX_DATA_LAST))
+			ret = 0;
+	}
+
+	if (ret)
+		debug("%s: Error while receiving bufer (err = %d)\n",
+		      dev->name, ret);
+
+	return ret;
+}
+
+static int gdsys_ioep_receive(struct udevice *dev, int offset, void *buf,
+			      int size)
+{
+	int ret;
+	struct io_generic_packet header;
+	u16 *p = (u16 *)buf;
+	const int header_words = sizeof(struct io_generic_packet) / sizeof(u16);
+	uint len;
+
+	/* Read the packet header */
+	ret = receive_byte_buffer(dev, header_words, p, READ_DATA_IS_NOT_LAST);
+	if (ret) {
+		debug("%s: Failed to read header data (err = %d)\n",
+		      dev->name, ret);
+		return ret;
+	}
+
+	memcpy(&header, p, header_words * sizeof(u16));
+	p += header_words;
+
+	/* Get payload data length */
+	len = (header.packet_length + 1) / sizeof(u16);
+
+	/* Read the packet payload */
+	ret = receive_byte_buffer(dev, len, p, READ_DATA_IS_LAST);
+	if (ret) {
+		debug("%s: Failed to read payload data (err = %d)\n",
+		      dev->name, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int gdsys_ioep_get_and_reset_status(struct udevice *dev, int msgid,
+					   void *tx_msg, int tx_size,
+					   void *rx_msg, int rx_size)
+{
+	struct gdsys_ioep_priv *priv = dev_get_priv(dev);
+	const u16 mask = STATE_RX_DIST_ERR | STATE_RX_LENGTH_ERR |
+			 STATE_RX_FRAME_CTR_ERR | STATE_RX_FCS_ERR |
+			 STATE_RX_PACKET_DROPPED | STATE_TX_ERR;
+	u16 *status = rx_msg;
+
+	gdsys_ioep_get(priv->map, rx_tx_status, status);
+
+	gdsys_ioep_set(priv->map, rx_tx_status, *status);
+
+	return (*status & mask) ? 1 : 0;
+}
+
+static const struct misc_ops gdsys_ioep_ops = {
+	.set_enabled = gdsys_ioep_set_receive,
+	.write = gdsys_ioep_send,
+	.read = gdsys_ioep_receive,
+	.call = gdsys_ioep_get_and_reset_status,
+};
+
+static int gdsys_ioep_probe(struct udevice *dev)
+{
+	struct gdsys_ioep_priv *priv = dev_get_priv(dev);
+	int ret;
+
+	ret = regmap_init_mem(dev_ofnode(dev), &priv->map);
+	if (ret) {
+		debug("%s: Could not initialize regmap (err = %d)",
+		      dev->name, ret);
+		return ret;
+	}
+
+	priv->state = false;
+
+	return 0;
+}
+
+static const struct udevice_id gdsys_ioep_ids[] = {
+	{ .compatible = "gdsys,io-endpoint" },
+	{ }
+};
+
+U_BOOT_DRIVER(gdsys_ioep) = {
+	.name           = "gdsys_ioep",
+	.id             = UCLASS_MISC,
+	.ops		= &gdsys_ioep_ops,
+	.flags		= DM_UC_FLAG_SEQ_ALIAS,
+	.of_match       = gdsys_ioep_ids,
+	.probe          = gdsys_ioep_probe,
+	.priv_auto_alloc_size = sizeof(struct gdsys_ioep_priv),
+};

drivers/misc/gdsys_ioep.h

@@ -0,0 +1,137 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * (C) Copyright 2018
+ * Mario Six, Guntermann & Drunck GmbH, mario.six@gdsys.cc
+ */
+
+#ifndef __GDSYS_IOEP_H_
+#define __GDSYS_IOEP_H_
+
+/**
+ * struct io_generic_packet - header structure for GDSYS IOEP packets
+ * @target_address:     Target protocol address of the packet.
+ * @source_address:     Source protocol address of the packet.
+ * @packet_type:        Packet type.
+ * @bc:                 Block counter (filled in by FPGA).
+ * @packet_length:      Length of the packet's payload bytes.
+ */
+struct io_generic_packet {
+	u16 target_address;
+	u16 source_address;
+	u8 packet_type;
+	u8 bc;
+	u16 packet_length;
+} __attribute__((__packed__));
+
+/**
+ * struct gdsys_ioep_regs - Registers of a IOEP device
+ * @transmit_data:  Register that receives data to be sent
+ * @tx_control:     TX control register
+ * @receive_data:   Register filled with the received data
+ * @rx_tx_status:   RX/TX status register
+ * @device_address: Register for setting/reading the device's address
+ * @target_address: Register for setting/reading the remote endpoint's address
+ * @int_enable:     Interrupt/Interrupt enable register
+ */
+struct gdsys_ioep_regs {
+	u16 transmit_data;
+	u16 tx_control;
+	u16 receive_data;
+	u16 rx_tx_status;
+	u16 device_address;
+	u16 target_address;
+	u16 int_enable;
+};
+
+/**
+ * gdsys_ioep_set() - Convenience macro to write registers of a IOEP device
+ * @map:    Register map to write the value in
+ * @member: Name of the member in the gdsys_ioep_regs structure to write
+ * @val:    Value to write to the register
+ */
+#define gdsys_ioep_set(map, member, val) \
+	regmap_set(map, struct gdsys_ioep_regs, member, val)
+
+/**
+ * gdsys_ioep_get() - Convenience macro to read registers of a IOEP device
+ * @map:    Register map to read the value from
+ * @member: Name of the member in the gdsys_ioep_regs structure to read
+ * @valp:   Pointer to buffer to read the register value into
+ */
+#define gdsys_ioep_get(map, member, valp) \
+	regmap_get(map, struct gdsys_ioep_regs, member, valp)
+
+/**
+ * enum rx_tx_status_values - Enum to describe the fields of the rx_tx_status
+ *			      register
+ * @STATE_TX_PACKET_BUILDING:      The device is currently building a packet
+ *				   (and accepting data for it)
+ * @STATE_TX_TRANSMITTING:         A packet is currenly being transmitted
+ * @STATE_TX_BUFFER_FULL:          The TX buffer is full
+ * @STATE_TX_ERR:                  A TX error occurred
+ * @STATE_RECEIVE_TIMEOUT:         A receive timeout occurred
+ * @STATE_PROC_RX_STORE_TIMEOUT:   A RX store timeout for a processor packet
+ *				   occurred
+ * @STATE_PROC_RX_RECEIVE_TIMEOUT: A RX receive timeout for a processor packet
+ *				   occurred
+ * @STATE_RX_DIST_ERR:             A error occurred in the distribution block
+ * @STATE_RX_LENGTH_ERR:           A length invalid error occurred
+ * @STATE_RX_FRAME_CTR_ERR:        A frame count error occurred (two
+ *				   non-increasing frame count numbers
+ *				   encountered)
+ * @STATE_RX_FCS_ERR:              A CRC error occurred
+ * @STATE_RX_PACKET_DROPPED:       A RX packet has been dropped
+ * @STATE_RX_DATA_LAST:            The data to be read is the final data of the
+ *				   current packet
+ * @STATE_RX_DATA_FIRST:           The data to be read is the first data of the
+ *				   current packet
+ * @STATE_RX_DATA_AVAILABLE:       RX data is available to be read
+ */
+enum rx_tx_status_values {
+	STATE_TX_PACKET_BUILDING = BIT(0),
+	STATE_TX_TRANSMITTING = BIT(1),
+	STATE_TX_BUFFER_FULL = BIT(2),
+	STATE_TX_ERR = BIT(3),
+	STATE_RECEIVE_TIMEOUT = BIT(4),
+	STATE_PROC_RX_STORE_TIMEOUT = BIT(5),
+	STATE_PROC_RX_RECEIVE_TIMEOUT = BIT(6),
+	STATE_RX_DIST_ERR = BIT(7),
+	STATE_RX_LENGTH_ERR = BIT(8),
+	STATE_RX_FRAME_CTR_ERR = BIT(9),
+	STATE_RX_FCS_ERR = BIT(10),
+	STATE_RX_PACKET_DROPPED = BIT(11),
+	STATE_RX_DATA_LAST = BIT(12),
+	STATE_RX_DATA_FIRST = BIT(13),
+	STATE_RX_DATA_AVAILABLE = BIT(15),
+};
+
+/**
+ * enum tx_control_values - Enum to describe the fields of the tx_control
+ *			    register
+ * @CTRL_PROC_RECEIVE_ENABLE:   Enable packet reception for the processor
+ * @CTRL_FLUSH_TRANSMIT_BUFFER: Flush the transmit buffer (and send packet data)
+ */
+enum tx_control_values {
+	CTRL_PROC_RECEIVE_ENABLE = BIT(12),
+	CTRL_FLUSH_TRANSMIT_BUFFER = BIT(15),
+};
+
+/**
+ * enum int_enable_values - Enum to describe the fields of the int_enable
+ *			    register
+ * @IRQ_CPU_TRANSMITBUFFER_FREE_STATUS:    The transmit buffer is free (packet
+ *					   data can be transmitted to the
+ *					   device)
+ * @IRQ_CPU_PACKET_TRANSMITTED_EVENT:      A packet has been transmitted
+ * @IRQ_NEW_CPU_PACKET_RECEIVED_EVENT:     A new packet has been received
+ * @IRQ_CPU_RECEIVE_DATA_AVAILABLE_STATUS: RX packet data are available to be
+ *					   read
+ */
+enum int_enable_values {
+	IRQ_CPU_TRANSMITBUFFER_FREE_STATUS = BIT(5),
+	IRQ_CPU_PACKET_TRANSMITTED_EVENT = BIT(6),
+	IRQ_NEW_CPU_PACKET_RECEIVED_EVENT = BIT(7),
+	IRQ_CPU_RECEIVE_DATA_AVAILABLE_STATUS = BIT(8),
+};
+
+#endif /* __GDSYS_IOEP_H_ */

drivers/misc/misc-uclass.c

@@ -55,6 +55,16 @@ int misc_call(struct udevice *dev, int msgid, void *tx_msg, int tx_size,
 	return ops->call(dev, msgid, tx_msg, tx_size, rx_msg, rx_size);
 }
 
+int misc_set_enabled(struct udevice *dev, bool val)
+{
+	const struct misc_ops *ops = device_get_ops(dev);
+
+	if (!ops->set_enabled)
+		return -ENOSYS;
+
+	return ops->set_enabled(dev, val);
+}
+
 UCLASS_DRIVER(misc) = {
 	.id		= UCLASS_MISC,
 	.name		= "misc",

drivers/misc/misc_sandbox.c

@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2018
+ * Mario Six, Guntermann & Drunck GmbH, mario.six@gdsys.cc
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <misc.h>
+
+struct misc_sandbox_priv {
+	u8 mem[128];
+	ulong last_ioctl;
+	bool enabled;
+};
+
+int misc_sandbox_read(struct udevice *dev, int offset, void *buf, int size)
+{
+	struct misc_sandbox_priv *priv = dev_get_priv(dev);
+
+	memcpy(buf, priv->mem + offset, size);
+
+	return 0;
+}
+
+int misc_sandbox_write(struct udevice *dev, int offset, const void *buf,
+		       int size)
+{
+	struct misc_sandbox_priv *priv = dev_get_priv(dev);
+
+	memcpy(priv->mem + offset, buf, size);
+
+	return 0;
+}
+
+int misc_sandbox_ioctl(struct udevice *dev, unsigned long request, void *buf)
+{
+	struct misc_sandbox_priv *priv = dev_get_priv(dev);
+
+	priv->last_ioctl = request;
+
+	return 0;
+}
+
+int misc_sandbox_call(struct udevice *dev, int msgid, void *tx_msg,
+		      int tx_size, void *rx_msg, int rx_size)
+{
+	struct misc_sandbox_priv *priv = dev_get_priv(dev);
+
+	if (msgid == 0) {
+		int num = *(int *)tx_msg;
+
+		switch (num) {
+		case 0:
+			strncpy(rx_msg, "Zero", rx_size);
+			break;
+		case 1:
+			strncpy(rx_msg, "One", rx_size);
+			break;
+		case 2:
+			strncpy(rx_msg, "Two", rx_size);
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	if (msgid == 1) {
+		int num = *(int *)tx_msg;
+
+		switch (num) {
+		case 0:
+			strncpy(rx_msg, "Forty", rx_size);
+			break;
+		case 1:
+			strncpy(rx_msg, "Forty-one", rx_size);
+			break;
+		case 2:
+			strncpy(rx_msg, "Forty-two", rx_size);
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+
+	if (msgid == 2)
+		memcpy(rx_msg, &priv->last_ioctl, sizeof(priv->last_ioctl));
+
+	if (msgid == 3)
+		memcpy(rx_msg, &priv->enabled, sizeof(priv->enabled));
+
+	return 0;
+}
+
+int misc_sandbox_set_enabled(struct udevice *dev, bool val)
+{
+	struct misc_sandbox_priv *priv = dev_get_priv(dev);
+
+	priv->enabled = !priv->enabled;
+
+	return 0;
+}
+
+static const struct misc_ops misc_sandbox_ops = {
+	.read = misc_sandbox_read,
+	.write = misc_sandbox_write,
+	.ioctl = misc_sandbox_ioctl,
+	.call = misc_sandbox_call,
+	.set_enabled = misc_sandbox_set_enabled,
+};
+
+int misc_sandbox_probe(struct udevice *dev)
+{
+	struct misc_sandbox_priv *priv = dev_get_priv(dev);
+
+	priv->enabled = true;
+
+	return 0;
+}
+
+static const struct udevice_id misc_sandbox_ids[] = {
+	{ .compatible = "sandbox,misc_sandbox" },
+	{ }
+};
+
+U_BOOT_DRIVER(misc_sandbox) = {
+	.name           = "misc_sandbox",
+	.id             = UCLASS_MISC,
+	.ops		= &misc_sandbox_ops,
+	.of_match       = misc_sandbox_ids,
+	.probe          = misc_sandbox_probe,
+	.priv_auto_alloc_size = sizeof(struct misc_sandbox_priv),
+};

include/misc.h

@@ -6,38 +6,47 @@
 #ifndef _MISC_H_
 #define _MISC_H_
 
-/*
- * Read the device to buffer, optional.
- *
+/**
+ * misc_read() - Read the device to buffer, optional.
  * @dev: the device
  * @offset: offset to read the device
  * @buf: pointer to data buffer
  * @size: data size in bytes to read the device
- * @return: 0 if OK, -ve on error
+ *
+ * Return: 0 if OK, -ve on error
  */
 int misc_read(struct udevice *dev, int offset, void *buf, int size);
-/*
- * Write buffer to the device, optional.
- *
+
+/**
+ * misc_write() - Write buffer to the device, optional.
  * @dev: the device
  * @offset: offset to write the device
  * @buf: pointer to data buffer
  * @size: data size in bytes to write the device
- * @return: 0 if OK, -ve on error
+ *
+ * Return: 0 if OK, -ve on error
  */
 int misc_write(struct udevice *dev, int offset, void *buf, int size);
-/*
- * Assert command to the device, optional.
- *
+
+/**
+ * misc_ioctl() - Assert command to the device, optional.
  * @dev: the device
  * @request: command to be sent to the device
  * @buf: pointer to buffer related to the request
- * @return: 0 if OK, -ve on error
+ *
+ * Return: 0 if OK, -ve on error
  */
 int misc_ioctl(struct udevice *dev, unsigned long request, void *buf);
 
-/*
- * Send a message to the device and wait for a response.
+/**
+ * misc_call() - Send a message to the device and wait for a response.
+ * @dev: the device.
+ * @msgid: the message ID/number to send.
+ * @tx_msg: the request/transmit message payload.
+ * @tx_size: the size of the buffer pointed at by tx_msg.
+ * @rx_msg: the buffer to receive the response message payload. May be NULL if
+ *          the caller only cares about the error code.
+ * @rx_size: the size of the buffer pointed at by rx_msg.
  *
  * The caller provides the message type/ID and payload to be sent.
  * The callee constructs any message header required, transmits it to the
@@ -45,18 +54,28 @@ int misc_ioctl(struct udevice *dev, unsigned long request, void *buf);
  * strips any message header from the response, and returns the error code
  * (or a parsed version of it) and the response message payload.
  *
- * @dev: the device.
- * @msgid: the message ID/number to send.
- * tx_msg: the request/transmit message payload.
- * tx_size: the size of the buffer pointed at by tx_msg.
- * rx_msg: the buffer to receive the response message payload. May be NULL if
- *         the caller only cares about the error code.
- * rx_size: the size of the buffer pointed at by rx_msg.
- * @return the response message size if OK, -ve on error
+ * Return: the response message size if OK, -ve on error
  */
 int misc_call(struct udevice *dev, int msgid, void *tx_msg, int tx_size,
 	      void *rx_msg, int rx_size);
 
+/**
+ * misc_set_enabled() - Enable or disable a device.
+ * @dev: the device to enable or disable.
+ * @val: the flag that tells the driver to either enable or disable the device.
+ *
+ * The semantics of "disable" and "enable" should be understood here as
+ * activating or deactivating the device's primary function, hence a "disabled"
+ * device should be dormant, but still answer to commands and queries.
+ *
+ * A probed device may start in a disabled or enabled state, depending on the
+ * driver and hardware.
+ *
+ * Return: -ve on error, 0 if the previous state was "disabled", 1 if the
+ *	   previous state was "enabled"
+ */
+int misc_set_enabled(struct udevice *dev, bool val);
+
 /*
  * struct misc_ops - Driver model Misc operations
  *
@@ -64,50 +83,62 @@ int misc_call(struct udevice *dev, int msgid, void *tx_msg, int tx_size,
  * use driver model.
  */
 struct misc_ops {
-	/*
+	/**
 	 * Read the device to buffer, optional.
-	 *
 	 * @dev: the device
 	 * @offset: offset to read the device
 	 * @buf: pointer to data buffer
 	 * @size: data size in bytes to read the device
-	 * @return: 0 if OK, -ve on error
+	 *
+	 * Return: 0 if OK, -ve on error
 	 */
 	int (*read)(struct udevice *dev, int offset, void *buf, int size);
-	/*
+
+	/**
 	 * Write buffer to the device, optional.
-	 *
 	 * @dev: the device
 	 * @offset: offset to write the device
 	 * @buf: pointer to data buffer
 	 * @size: data size in bytes to write the device
-	 * @return: 0 if OK, -ve on error
+	 *
+	 * Return: 0 if OK, -ve on error
 	 */
 	int (*write)(struct udevice *dev, int offset, const void *buf,
 		     int size);
-	/*
+	/**
 	 * Assert command to the device, optional.
-	 *
 	 * @dev: the device
 	 * @request: command to be sent to the device
 	 * @buf: pointer to buffer related to the request
-	 * @return: 0 if OK, -ve on error
+	 *
+	 * Return: 0 if OK, -ve on error
 	 */
 	int (*ioctl)(struct udevice *dev, unsigned long request, void *buf);
-	/*
+
+	/**
 	 * Send a message to the device and wait for a response.
-	 *
 	 * @dev: the device
 	 * @msgid: the message ID/number to send
-	 * tx_msg: the request/transmit message payload
-	 * tx_size: the size of the buffer pointed at by tx_msg
-	 * rx_msg: the buffer to receive the response message payload. May be
-	 *         NULL if the caller only cares about the error code.
-	 * rx_size: the size of the buffer pointed at by rx_msg
-	 * @return the response message size if OK, -ve on error
+	 * @tx_msg: the request/transmit message payload
+	 * @tx_size: the size of the buffer pointed at by tx_msg
+	 * @rx_msg: the buffer to receive the response message payload. May be
+	 *          NULL if the caller only cares about the error code.
+	 * @rx_size: the size of the buffer pointed at by rx_msg
+	 *
+	 * Return: the response message size if OK, -ve on error
 	 */
 	int (*call)(struct udevice *dev, int msgid, void *tx_msg, int tx_size,
 		    void *rx_msg, int rx_size);
+	/**
+	 * Enable or disable a device, optional.
+	 * @dev: the device to enable.
+	 * @val: the flag that tells the driver to either enable or disable the
+	 *	 device.
+	 *
+	 * Return: -ve on error, 0 if the previous state was "disabled", 1 if
+	 *	   the previous state was "enabled"
+	 */
+	int (*set_enabled)(struct udevice *dev, bool val);
 };
 
 #endif	/* _MISC_H_ */

test/dm/Makefile

@@ -45,4 +45,5 @@ obj-$(CONFIG_ADC) += adc.o
 obj-$(CONFIG_SPMI) += spmi.o
 obj-$(CONFIG_WDT) += wdt.o
 obj-$(CONFIG_AXI) += axi.o
+obj-$(CONFIG_MISC) += misc.o
 endif

test/dm/misc.c

@@ -0,0 +1,83 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * (C) Copyright 2018
+ * Mario Six, Guntermann & Drunck GmbH, mario.six@gdsys.cc
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/test.h>
+#include <misc.h>
+#include <test/ut.h>
+
+static int dm_test_misc(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+	u8 buf[16];
+	int id;
+	ulong last_ioctl;
+	bool enabled;
+
+	ut_assertok(uclass_get_device_by_name(UCLASS_MISC, "misc-test", &dev));
+
+	/* Read / write tests */
+	ut_assertok(misc_write(dev, 0, "TEST", 4));
+	ut_assertok(misc_write(dev, 4, "WRITE", 5));
+	ut_assertok(misc_read(dev, 0, buf, 9));
+
+	ut_assertok(memcmp(buf, "TESTWRITE", 9));
+
+	/* Call tests */
+
+	id = 0;
+	ut_assertok(misc_call(dev, 0, &id, 4, buf, 16));
+	ut_assertok(memcmp(buf, "Zero", 4));
+
+	id = 2;
+	ut_assertok(misc_call(dev, 0, &id, 4, buf, 16));
+	ut_assertok(memcmp(buf, "Two", 3));
+
+	ut_assertok(misc_call(dev, 1, &id, 4, buf, 16));
+	ut_assertok(memcmp(buf, "Forty-two", 9));
+
+	id = 1;
+	ut_assertok(misc_call(dev, 1, &id, 4, buf, 16));
+	ut_assertok(memcmp(buf, "Forty-one", 9));
+
+	/* IOCTL tests */
+
+	ut_assertok(misc_ioctl(dev, 6, NULL));
+	/* Read back last issued ioctl */
+	ut_assertok(misc_call(dev, 2, NULL, 0, &last_ioctl,
+			      sizeof(last_ioctl)));
+	ut_asserteq(6, last_ioctl)
+
+	ut_assertok(misc_ioctl(dev, 23, NULL));
+	/* Read back last issued ioctl */
+	ut_assertok(misc_call(dev, 2, NULL, 0, &last_ioctl,
+			      sizeof(last_ioctl)));
+	ut_asserteq(23, last_ioctl)
+
+	/* Enable / disable tests */
+
+	/* Read back enable/disable status */
+	ut_assertok(misc_call(dev, 3, NULL, 0, &enabled,
+			      sizeof(enabled)));
+	ut_asserteq(true, enabled);
+
+	ut_assertok(misc_set_enabled(dev, false));
+	/* Read back enable/disable status */
+	ut_assertok(misc_call(dev, 3, NULL, 0, &enabled,
+			      sizeof(enabled)));
+	ut_asserteq(false, enabled);
+
+	ut_assertok(misc_set_enabled(dev, true));
+	/* Read back enable/disable status */
+	ut_assertok(misc_call(dev, 3, NULL, 0, &enabled,
+			      sizeof(enabled)));
+	ut_asserteq(true, enabled);
+
+	return 0;
+}
+
+DM_TEST(dm_test_misc, DM_TESTF_SCAN_FDT);