[PATCH v4 4/5] mikrobus: Add mikroBUS driver
From: Ayush Singh
Date: Sun Mar 17 2024 - 15:39:17 EST
DONOTMERGE
this patch depends on Patch 1, 2, 3
mikroBUS driver aims to split the platform aspects of mikroBUS (pinmux,
SPI/I2C/GPIO controller .etc) from the add-on board information, thus
requiring one device tree overlay per port and just a single manifest
describing the add-on board.
The driver exposes a sysfs entry that allows passing mikroBUS manifest of
add-on board to the driver. The driver then parses this manifest, sets up
the pins and protocols and allows using the appropriate Linux driver. Here
is an example:
```
cat /lib/firmware/mikrobus/AMBIENT-2-CLICK.mnfb > /sys/bus/mikrobus/devices/mikrobus-0/new_device
```
Another sysfs entry is exposed that allows removing a previously
registered mikrobus add-on board:
```
echo " " > /sys/bus/mikrobus/devices/mikrobus-0/delete_device
```
100s of mikroBUS addon board manifests can be found in the clickID
repository.
In the future the driver also aims to support plug and play support
using 1-wire EEPROM and mikroBUS over greybus.
Link: https://www.mikroe.com/clickid ClickID
Co-developed-by: Vaishnav M A <vaishnav@xxxxxxxxxxxxxxx>
Signed-off-by: Vaishnav M A <vaishnav@xxxxxxxxxxxxxxx>
Signed-off-by: Ayush Singh <ayushdevel1325@xxxxxxxxx>
---
MAINTAINERS | 1 +
drivers/misc/Kconfig | 1 +
drivers/misc/Makefile | 1 +
drivers/misc/mikrobus/Kconfig | 15 +
drivers/misc/mikrobus/Makefile | 5 +
drivers/misc/mikrobus/mikrobus_core.c | 696 ++++++++++++++++++++++
drivers/misc/mikrobus/mikrobus_core.h | 151 +++++
drivers/misc/mikrobus/mikrobus_manifest.c | 503 ++++++++++++++++
drivers/misc/mikrobus/mikrobus_manifest.h | 29 +
9 files changed, 1402 insertions(+)
create mode 100644 drivers/misc/mikrobus/Kconfig
create mode 100644 drivers/misc/mikrobus/Makefile
create mode 100644 drivers/misc/mikrobus/mikrobus_core.c
create mode 100644 drivers/misc/mikrobus/mikrobus_core.h
create mode 100644 drivers/misc/mikrobus/mikrobus_manifest.c
create mode 100644 drivers/misc/mikrobus/mikrobus_manifest.h
diff --git a/MAINTAINERS b/MAINTAINERS
index 69418a058c6b..83bc5e48bef9 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -14772,6 +14772,7 @@ M: Ayush Singh <ayushdevel1325@xxxxxxxxx>
M: Vaishnav M A <vaishnav@xxxxxxxxxxxxxxx>
S: Maintained
F: Documentation/devicetree/bindings/misc/mikrobus-connector.yaml
+F: drivers/misc/mikrobus/*
MIKROTIK CRS3XX 98DX3236 BOARD SUPPORT
M: Luka Kovacic <luka.kovacic@xxxxxxxxxx>
diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index 4fb291f0bf7c..3d5c36205c6c 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -591,4 +591,5 @@ source "drivers/misc/cardreader/Kconfig"
source "drivers/misc/uacce/Kconfig"
source "drivers/misc/pvpanic/Kconfig"
source "drivers/misc/mchp_pci1xxxx/Kconfig"
+source "drivers/misc/mikrobus/Kconfig"
endmenu
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index ea6ea5bbbc9c..b9ac88055b87 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -68,3 +68,4 @@ obj-$(CONFIG_TMR_INJECT) += xilinx_tmr_inject.o
obj-$(CONFIG_TPS6594_ESM) += tps6594-esm.o
obj-$(CONFIG_TPS6594_PFSM) += tps6594-pfsm.o
obj-$(CONFIG_NSM) += nsm.o
+obj-y += mikrobus/
diff --git a/drivers/misc/mikrobus/Kconfig b/drivers/misc/mikrobus/Kconfig
new file mode 100644
index 000000000000..aa57b994dc66
--- /dev/null
+++ b/drivers/misc/mikrobus/Kconfig
@@ -0,0 +1,15 @@
+menuconfig MIKROBUS
+ tristate "Module for instantiating devices on mikroBUS ports"
+ depends on GPIOLIB
+ help
+ This option enables the mikroBUS driver. mikroBUS is an add-on
+ board socket standard that offers maximum expandability with
+ the smallest number of pins. The mikroBUS driver instantiates
+ devices on a mikroBUS port described mikroBUS manifest which is
+ passed using a sysfs interface.
+
+
+ Say Y here to enable support for this driver.
+
+ To compile this code as a module, chose M here: the module
+ will be called mikrobus.ko
diff --git a/drivers/misc/mikrobus/Makefile b/drivers/misc/mikrobus/Makefile
new file mode 100644
index 000000000000..0e51c5a7db4b
--- /dev/null
+++ b/drivers/misc/mikrobus/Makefile
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0
+# mikroBUS Core
+
+obj-$(CONFIG_MIKROBUS) += mikrobus.o
+mikrobus-y := mikrobus_core.o mikrobus_manifest.o
diff --git a/drivers/misc/mikrobus/mikrobus_core.c b/drivers/misc/mikrobus/mikrobus_core.c
new file mode 100644
index 000000000000..6aa20cef8e3b
--- /dev/null
+++ b/drivers/misc/mikrobus/mikrobus_core.c
@@ -0,0 +1,696 @@
+// SPDX-License-Identifier: GPL-2.0:
+/*
+ * mikroBUS driver for instantiating add-on
+ * board devices with an identifier EEPROM
+ *
+ * Copyright 2020 Vaishnav M A, BeagleBoard.org Foundation.
+ * Copyright 2024 Ayush Singh <ayushdevel1325@xxxxxxxxx>
+ */
+
+#define pr_fmt(fmt) "mikrobus:%s: " fmt, __func__
+
+#include "linux/gpio/driver.h"
+#include "linux/gpio/machine.h"
+#include "linux/gpio/consumer.h"
+#include "linux/greybus/greybus_manifest.h"
+#include "linux/i2c.h"
+#include "linux/irq.h"
+#include "linux/pinctrl/consumer.h"
+#include "linux/platform_device.h"
+#include "linux/spi/spi.h"
+
+#include "mikrobus_core.h"
+#include "mikrobus_manifest.h"
+
+static struct class_compat *mikrobus_port_compat_class;
+
+static const struct bus_type mikrobus_bus_type = {
+ .name = "mikrobus",
+};
+
+static int mikrobus_board_register(struct mikrobus_port *port,
+ struct addon_board_info *board);
+static void mikrobus_board_unregister(struct mikrobus_port *port,
+ struct addon_board_info *board);
+
+/*
+ * mikrobus_pinctrl_select: Select pinctrl state for mikrobus pin
+ *
+ * @port: mikrobus port
+ * @pinctrl_selected: pinctrl state to be selected
+ */
+static int mikrobus_pinctrl_select(struct mikrobus_port *port,
+ const char *pinctrl_selected)
+{
+ struct pinctrl_state *state;
+ int ret;
+
+ state = pinctrl_lookup_state(port->pinctrl, pinctrl_selected);
+ if (IS_ERR(state)) {
+ return dev_err_probe(&port->dev, PTR_ERR(state),
+ "failed to find state %s",
+ pinctrl_selected);
+ }
+
+ ret = pinctrl_select_state(port->pinctrl, state);
+ if (ret) {
+ return dev_err_probe(&port->dev, ret,
+ "failed to select state %s",
+ pinctrl_selected);
+ }
+ dev_dbg(&port->dev, "setting pinctrl %s", pinctrl_selected);
+
+ return 0;
+}
+
+/*
+ * mikrobus_pinctrl_setup: Setup mikrobus pins to either default of gpio
+ *
+ * @port: mikrobus port
+ * @board: mikrobus board or NULL for default state
+ *
+ * returns 0 on success, negative error code on failure
+ */
+static int mikrobus_pinctrl_setup(struct mikrobus_port *port,
+ struct addon_board_info *board)
+{
+ int ret;
+
+ if (!board || board->pin_state[MIKROBUS_PIN_PWM] == MIKROBUS_STATE_PWM)
+ ret = mikrobus_pinctrl_select(port, "pwm_default");
+ else
+ ret = mikrobus_pinctrl_select(port, "pwm_gpio");
+ if (ret)
+ return ret;
+
+ if (!board || board->pin_state[MIKROBUS_PIN_RX] == MIKROBUS_STATE_UART)
+ ret = mikrobus_pinctrl_select(port, "uart_default");
+ else
+ ret = mikrobus_pinctrl_select(port, "uart_gpio");
+ if (ret)
+ return ret;
+
+ if (!board || board->pin_state[MIKROBUS_PIN_SCL] == MIKROBUS_STATE_I2C)
+ ret = mikrobus_pinctrl_select(port, "i2c_default");
+ else
+ ret = mikrobus_pinctrl_select(port, "i2c_gpio");
+ if (ret)
+ return ret;
+
+ if (!board || board->pin_state[MIKROBUS_PIN_MOSI] == MIKROBUS_STATE_SPI)
+ ret = mikrobus_pinctrl_select(port, "spi_default");
+ else
+ ret = mikrobus_pinctrl_select(port, "spi_gpio");
+
+ return ret;
+}
+
+/*
+ * new_device_store: Expose sysfs entry for adding new board
+ *
+ * new_device_store: Allows userspace to add mikroBUS boards that lack 1-wire
+ * EEPROM for board identification by manually passing mikroBUS manifest
+ */
+static ssize_t new_device_store(struct device *dev,
+ struct device_attribute *attr, const char *buf,
+ size_t count)
+{
+ struct mikrobus_port *port = to_mikrobus_port(dev);
+ struct addon_board_info *board;
+ int ret;
+
+ if (port->board)
+ return dev_err_probe(dev, -EBUSY,
+ "already has board registered");
+
+ board = devm_kzalloc(&port->dev, sizeof(*board), GFP_KERNEL);
+ if (!board)
+ return -ENOMEM;
+
+ INIT_LIST_HEAD(&board->manifest_descs);
+ INIT_LIST_HEAD(&board->devices);
+
+ ret = mikrobus_manifest_parse(board, (void *)buf, count);
+ if (ret < 0) {
+ ret = dev_err_probe(dev, -EINVAL, "failed to parse manifest");
+ goto err_free_board;
+ }
+
+ ret = mikrobus_board_register(port, board);
+ if (ret) {
+ ret = dev_err_probe(dev, -EINVAL, "failed to register board %s",
+ board->name);
+ goto err_free_board;
+ }
+
+ return count;
+
+err_free_board:
+ devm_kfree(&port->dev, board);
+ return ret;
+}
+static DEVICE_ATTR_WO(new_device);
+
+/*
+ * delete_device_store: Expose sysfs entry for deleting board
+ */
+static ssize_t delete_device_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct mikrobus_port *port = to_mikrobus_port(dev);
+
+ if (!port->board)
+ return dev_err_probe(dev, -ENODEV,
+ "does not have registered boards");
+
+ mikrobus_board_unregister(port, port->board);
+ return count;
+}
+static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, 0200, NULL,
+ delete_device_store);
+
+static struct attribute *mikrobus_port_attrs[] = { &dev_attr_new_device.attr,
+ &dev_attr_delete_device.attr,
+ NULL };
+ATTRIBUTE_GROUPS(mikrobus_port);
+
+static void mikrobus_port_release(struct device *dev)
+{
+}
+
+static const struct device_type mikrobus_port_type = {
+ .groups = mikrobus_port_groups,
+ .release = mikrobus_port_release,
+};
+
+static int mikrobus_irq_get(struct mikrobus_port *port, int irqno, int irq_type)
+{
+ int irq;
+
+ if (irqno > port->gpios->ndescs - 1)
+ return dev_err_probe(&port->dev, -ENODEV,
+ "GPIO %d does not exist", irqno);
+
+ irq = gpiod_to_irq(port->gpios->desc[irqno]);
+ if (irq < 0)
+ return dev_err_probe(&port->dev, -EINVAL,
+ "could not get irq %d", irqno);
+
+ irq_set_irq_type(irq, irq_type);
+
+ return irq;
+}
+
+static int mikrobus_gpio_setup(struct gpio_desc *gpio, int gpio_state)
+{
+ switch (gpio_state) {
+ case MIKROBUS_STATE_INPUT:
+ return gpiod_direction_input(gpio);
+ case MIKROBUS_STATE_OUTPUT_HIGH:
+ return gpiod_direction_output(gpio, 1);
+ case MIKROBUS_STATE_OUTPUT_LOW:
+ return gpiod_direction_output(gpio, 0);
+ case MIKROBUS_STATE_PWM:
+ case MIKROBUS_STATE_SPI:
+ case MIKROBUS_STATE_I2C:
+ default:
+ return 0;
+ }
+}
+
+static char *mikrobus_gpio_chip_name_get(struct mikrobus_port *port, int gpio)
+{
+ struct gpio_chip *gpiochip;
+
+ if (gpio > port->gpios->ndescs - 1)
+ return NULL;
+
+ gpiochip = gpiod_to_chip(port->gpios->desc[gpio]);
+ return kmemdup(gpiochip->label, strlen(gpiochip->label), GFP_KERNEL);
+}
+
+static int mikrobus_gpio_hwnum_get(struct mikrobus_port *port, int gpio)
+{
+ struct gpio_chip *gpiochip;
+
+ if (gpio > port->gpios->ndescs - 1)
+ return -ENODEV;
+
+ gpiochip = gpiod_to_chip(port->gpios->desc[gpio]);
+ return desc_to_gpio(port->gpios->desc[gpio]) - gpiochip->base;
+}
+
+static void mikrobus_board_device_release_all(struct addon_board_info *info)
+{
+ struct board_device_info *dev, *next;
+
+ list_for_each_entry_safe(dev, next, &info->devices, links) {
+ list_del(&dev->links);
+ kfree(dev);
+ }
+}
+
+static int mikrobus_device_register(struct mikrobus_port *port,
+ struct board_device_info *dev,
+ char *board_name)
+{
+ struct gpiod_lookup_table *lookup;
+ struct spi_board_info *spi_info;
+ struct i2c_board_info *i2c_info;
+ struct platform_device *pdev;
+ struct fwnode_handle *fwnode;
+ struct spi_device *spi;
+ struct i2c_client *i2c;
+ int i, ret;
+
+ dev_info(&port->dev, "registering device : %s", dev->drv_name);
+
+ if (dev->gpio_lookup) {
+ lookup = dev->gpio_lookup;
+
+ switch (dev->protocol) {
+ case GREYBUS_PROTOCOL_SPI:
+ lookup->dev_id = kasprintf(GFP_KERNEL, "%s.%u",
+ dev->drv_name,
+ port->chip_select[dev->reg]);
+ break;
+ case GREYBUS_PROTOCOL_RAW:
+ lookup->dev_id = kasprintf(GFP_KERNEL, "%s.%u",
+ dev->drv_name, dev->reg);
+ break;
+ default:
+ lookup->dev_id = kmemdup(dev->drv_name,
+ strlen(dev->drv_name),
+ GFP_KERNEL);
+ }
+
+ dev_info(&port->dev, "adding lookup table : %s",
+ lookup->dev_id);
+
+ for (i = 0; i < dev->num_gpio_resources; i++) {
+ lookup->table[i].key = mikrobus_gpio_chip_name_get(
+ port, lookup->table[i].chip_hwnum);
+ lookup->table[i].chip_hwnum = mikrobus_gpio_hwnum_get(
+ port, lookup->table[i].chip_hwnum);
+ }
+
+ gpiod_add_lookup_table(lookup);
+ }
+
+ switch (dev->protocol) {
+ case GREYBUS_PROTOCOL_SPI:
+ spi_info =
+ devm_kzalloc(&port->dev, sizeof(*spi_info), GFP_KERNEL);
+ strscpy_pad(spi_info->modalias, dev->drv_name,
+ sizeof(spi_info->modalias));
+ if (dev->irq)
+ spi_info->irq =
+ mikrobus_irq_get(port, dev->irq, dev->irq_type);
+ if (dev->properties) {
+ fwnode = fwnode_create_software_node(dev->properties,
+ NULL);
+ spi_info->swnode = to_software_node(fwnode);
+ }
+ spi_info->chip_select = port->chip_select[dev->reg];
+ spi_info->max_speed_hz = dev->max_speed_hz;
+ spi_info->mode = dev->mode;
+
+ spi = spi_new_device(port->spi_ctrl, spi_info);
+ devm_kfree(&port->dev, spi_info);
+ if (!spi)
+ return dev_err_probe(&port->dev, -ENODEV,
+ "failed to register spi device");
+ dev->dev_client = (void *)spi;
+ break;
+ case GREYBUS_PROTOCOL_I2C:
+ i2c_info =
+ devm_kzalloc(&port->dev, sizeof(*i2c_info), GFP_KERNEL);
+ if (!i2c_info)
+ return -ENOMEM;
+
+ strscpy_pad(i2c_info->type, dev->drv_name,
+ sizeof(i2c_info->type));
+ if (dev->irq)
+ i2c_info->irq =
+ mikrobus_irq_get(port, dev->irq, dev->irq_type);
+ if (dev->properties) {
+ fwnode = fwnode_create_software_node(dev->properties,
+ NULL);
+ i2c_info->swnode = to_software_node(fwnode);
+ }
+ i2c_info->addr = dev->reg;
+
+ i2c = i2c_new_client_device(port->i2c_adap, i2c_info);
+ devm_kfree(&port->dev, i2c_info);
+ if (IS_ERR(dev->dev_client))
+ return dev_err_probe(&port->dev,
+ PTR_ERR(dev->dev_client),
+ "failed to register i2c device");
+ dev->dev_client = (void *)i2c;
+ break;
+ case GREYBUS_PROTOCOL_RAW:
+ pdev = platform_device_alloc(dev->drv_name, 0);
+ if (!pdev)
+ return -ENOMEM;
+
+ if (dev->properties) {
+ ret = device_create_managed_software_node(
+ &pdev->dev, dev->properties, NULL);
+ if (ret)
+ return dev_err_probe(
+ &port->dev, ret,
+ "failed to create software node");
+ }
+ ret = platform_device_add(dev->dev_client);
+ if (ret)
+ return dev_err_probe(
+ &port->dev, ret,
+ "failed to register platform device");
+ dev->dev_client = (void *)pdev;
+ break;
+ case GREYBUS_PROTOCOL_UART:
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void mikrobus_device_unregister(struct mikrobus_port *port,
+ struct board_device_info *dev,
+ char *board_name)
+{
+ dev_info(&port->dev, "removing device %s", dev->drv_name);
+ if (dev->gpio_lookup) {
+ gpiod_remove_lookup_table(dev->gpio_lookup);
+ kfree(dev->gpio_lookup->dev_id);
+ kfree(dev->gpio_lookup);
+ }
+
+ kfree(dev->properties);
+
+ switch (dev->protocol) {
+ case GREYBUS_PROTOCOL_SPI:
+ spi_unregister_device((struct spi_device *)dev->dev_client);
+ break;
+ case GREYBUS_PROTOCOL_I2C:
+ i2c_unregister_device((struct i2c_client *)dev->dev_client);
+ break;
+ case GREYBUS_PROTOCOL_RAW:
+ platform_device_unregister(
+ (struct platform_device *)dev->dev_client);
+ break;
+ case GREYBUS_PROTOCOL_UART:
+ break;
+ }
+}
+
+static int mikrobus_board_register(struct mikrobus_port *port,
+ struct addon_board_info *board)
+{
+ struct board_device_info *devinfo, *next;
+ int ret, i;
+
+ if (WARN_ON(list_empty(&board->devices)))
+ return false;
+
+ if (port->pinctrl) {
+ ret = mikrobus_pinctrl_setup(port, board);
+ if (ret)
+ dev_err(&port->dev,
+ "failed to setup pinctrl state [%d]", ret);
+ }
+
+ if (port->gpios) {
+ for (i = 0; i < port->gpios->ndescs; i++) {
+ ret = mikrobus_gpio_setup(port->gpios->desc[i],
+ board->pin_state[i]);
+ if (ret)
+ dev_err(&port->dev,
+ "failed to setup gpio %d, state %d", i,
+ board->pin_state[i]);
+
+ gpiochip_free_own_desc(port->gpios->desc[i]);
+ }
+ }
+
+ list_for_each_entry_safe(devinfo, next, &board->devices, links)
+ mikrobus_device_register(port, devinfo, board->name);
+
+ port->board = board;
+ return 0;
+}
+
+static void mikrobus_board_unregister(struct mikrobus_port *port,
+ struct addon_board_info *board)
+{
+ struct board_device_info *devinfo, *next;
+
+ if (WARN_ON(list_empty(&board->devices)))
+ return;
+
+ list_for_each_entry_safe(devinfo, next, &board->devices, links)
+ mikrobus_device_unregister(port, devinfo, board->name);
+
+ mikrobus_board_device_release_all(board);
+ devm_kfree(&port->dev, board);
+ port->board = NULL;
+}
+
+static int mikrobus_port_register(struct mikrobus_port *port)
+{
+ int ret;
+
+ port->dev.bus = &mikrobus_bus_type;
+ port->dev.type = &mikrobus_port_type;
+ dev_set_name(&port->dev, "mikrobus-%d", port->id);
+
+ dev_info(&port->dev, "registering port %s", dev_name(&port->dev));
+
+ ret = device_register(&port->dev);
+ if (ret)
+ return dev_err_probe(&port->dev, ret,
+ "port '%d': can't register device (%d)",
+ port->id, ret);
+
+ ret = class_compat_create_link(mikrobus_port_compat_class, &port->dev,
+ port->dev.parent);
+ if (ret)
+ dev_warn(&port->dev,
+ "failed to create compatibility class link");
+
+ return ret;
+}
+
+static void mikrobus_port_delete(struct mikrobus_port *port)
+{
+ if (port->board)
+ return dev_err(
+ &port->dev,
+ "attempting to delete port with registered boards, port [%s]",
+ dev_name(&port->dev));
+
+ class_compat_remove_link(mikrobus_port_compat_class, &port->dev,
+ port->dev.parent);
+
+ devm_pinctrl_put(port->pinctrl);
+ put_device(&port->spi_ctrl->dev);
+ gpiod_put_array(port->gpios);
+ put_device(&port->i2c_adap->dev);
+
+ device_unregister(&port->dev);
+ memset(&port->dev, 0, sizeof(port->dev));
+}
+
+static int mikrobus_port_probe_pinctrl_setup(struct mikrobus_port *port)
+{
+ struct device *dev = port->dev.parent;
+ struct pinctrl_state *state;
+ int ret;
+
+ state = pinctrl_lookup_state(port->pinctrl, PINCTRL_STATE_DEFAULT);
+ if (IS_ERR(state))
+ return dev_err_probe(dev, PTR_ERR(state),
+ "failed to find state %s",
+ PINCTRL_STATE_DEFAULT);
+
+ ret = pinctrl_select_state(port->pinctrl, state);
+ if (ret)
+ return dev_err_probe(dev, ret, "Failed to select state %s",
+ PINCTRL_STATE_DEFAULT);
+
+ ret = mikrobus_pinctrl_setup(port, NULL);
+ if (ret)
+ dev_err(dev, "failed to select pinctrl states [%d]", ret);
+
+ return ret;
+}
+
+static int mikrobus_port_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct mikrobus_port *port;
+ struct device_node *np;
+ int ret;
+
+ port = devm_kzalloc(dev, sizeof(*port), GFP_KERNEL);
+ if (!port)
+ return -ENOMEM;
+
+ port->dev.parent = dev;
+ port->dev.of_node = pdev->dev.of_node;
+
+ /* port id */
+ port->id = of_alias_get_id(dev->of_node, "mikrobus");
+ if (port->id) {
+ ret = dev_err_probe(dev, -EINVAL, "invalid mikrobus id");
+ goto err_port;
+ }
+
+ /* I2C setup */
+ np = of_parse_phandle(dev->of_node, "i2c-adapter", 0);
+ if (!np) {
+ ret = dev_err_probe(dev, -ENODEV, "cannot parse i2c-adapter");
+ goto err_port;
+ }
+ port->i2c_adap = of_find_i2c_adapter_by_node(np);
+ of_node_put(np);
+ if (!port->i2c_adap) {
+ ret = dev_err_probe(dev, -ENODEV, "cannot find i2c adapter");
+ goto err_port;
+ }
+
+ /* GPIO setup */
+ port->gpios = gpiod_get_array(dev, "mikrobus", GPIOD_OUT_LOW);
+ if (IS_ERR(port->gpios)) {
+ ret = dev_err_probe(dev, PTR_ERR(port->gpios),
+ "failed to get gpio array [%ld]",
+ PTR_ERR(port->gpios));
+ goto free_i2c;
+ }
+
+ /* SPI setup */
+ np = of_parse_phandle(dev->of_node, "spi-controller", 0);
+ if (!np) {
+ ret = dev_err_probe(dev, -ENODEV,
+ "cannot parse spi-controller");
+ goto free_gpio;
+ }
+ port->spi_ctrl = of_find_spi_controller_by_node(np);
+ of_node_put(np);
+ if (!port->spi_ctrl) {
+ ret = dev_err_probe(dev, -ENODEV, "cannot find spi controller");
+ goto free_gpio;
+ }
+ ret = device_property_read_u32_array(dev, "spi-cs", port->chip_select,
+ MIKROBUS_NUM_CS);
+ if (ret) {
+ dev_err(dev, "failed to get spi-cs [%d]", ret);
+ goto free_spi;
+ }
+
+ /* pinctrl setup */
+ port->pinctrl = devm_pinctrl_get(dev);
+ if (IS_ERR(port->pinctrl)) {
+ ret = dev_err_probe(dev, PTR_ERR(port->pinctrl),
+ "failed to get pinctrl [%ld]",
+ PTR_ERR(port->pinctrl));
+ goto free_spi;
+ }
+ ret = mikrobus_port_probe_pinctrl_setup(port);
+ if (ret) {
+ dev_err(dev, "failed to setup pinctrl [%d]", ret);
+ goto free_pinctrl;
+ }
+
+ /* TODO: UART */
+ /* TODO: PWM */
+
+ ret = mikrobus_port_register(port);
+ if (ret) {
+ dev_err(dev, "port : can't register port [%d]", ret);
+ goto free_pinctrl;
+ }
+
+ platform_set_drvdata(pdev, port);
+
+ return 0;
+
+free_pinctrl:
+ devm_pinctrl_put(port->pinctrl);
+free_spi:
+ put_device(&port->spi_ctrl->dev);
+free_gpio:
+ gpiod_put_array(port->gpios);
+free_i2c:
+ put_device(&port->i2c_adap->dev);
+err_port:
+ put_device(&port->dev);
+ return ret;
+}
+
+static int mikrobus_port_remove(struct platform_device *pdev)
+{
+ struct mikrobus_port *port = platform_get_drvdata(pdev);
+
+ mikrobus_port_delete(port);
+ return 0;
+}
+
+static const struct of_device_id mikrobus_port_of_match[] = {
+ { .compatible = "mikrobus-connector" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, mikrobus_port_of_match);
+
+static struct platform_driver mikrobus_port_driver = {
+ .probe = mikrobus_port_probe,
+ .remove = mikrobus_port_remove,
+ .driver = {
+ .name = "mikrobus",
+ .of_match_table = mikrobus_port_of_match,
+ },
+};
+
+static int mikrobus_init(void)
+{
+ int ret;
+
+ ret = bus_register(&mikrobus_bus_type);
+ if (ret) {
+ pr_err("bus_register failed (%d)", ret);
+ return ret;
+ }
+
+ mikrobus_port_compat_class = class_compat_register("mikrobus-port");
+ if (!mikrobus_port_compat_class) {
+ ret = -ENOMEM;
+ pr_err("class_compat register failed (%d)", ret);
+ goto class_err;
+ }
+
+ ret = platform_driver_register(&mikrobus_port_driver);
+ if (ret)
+ pr_err("driver register failed [%d]", ret);
+
+ return ret;
+
+class_err:
+ bus_unregister(&mikrobus_bus_type);
+ return ret;
+}
+subsys_initcall(mikrobus_init);
+
+static void mikrobus_exit(void)
+{
+ platform_driver_unregister(&mikrobus_port_driver);
+ bus_unregister(&mikrobus_bus_type);
+ class_compat_unregister(mikrobus_port_compat_class);
+}
+module_exit(mikrobus_exit);
+
+MODULE_AUTHOR("Vaishnav M A <vaishnav@xxxxxxxxxxxxxxx>");
+MODULE_AUTHOR("Ayush Singh <ayushdevel1325@xxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("mikroBUS main module");
+MODULE_LICENSE("GPL");
diff --git a/drivers/misc/mikrobus/mikrobus_core.h b/drivers/misc/mikrobus/mikrobus_core.h
new file mode 100644
index 000000000000..1d41ee32ca94
--- /dev/null
+++ b/drivers/misc/mikrobus/mikrobus_core.h
@@ -0,0 +1,151 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * mikroBUS Driver for instantiating add-on board devices
+ *
+ * Copyright 2020 Vaishnav M A, BeagleBoard.org Foundation.
+ * Copyright 2024 Ayush Singh <ayushdevel1325@xxxxxxxxx>
+ */
+
+#ifndef __MIKROBUS_H
+#define __MIKROBUS_H
+
+#include "linux/device.h"
+
+#define MIKROBUS_VERSION_MAJOR 0x00
+#define MIKROBUS_VERSION_MINOR 0x03
+
+#define MIKROBUS_NUM_PINCTRL_STATE 4
+#define MIKROBUS_NUM_CS 2
+
+#define MIKROBUS_PINCTRL_PWM 0
+#define MIKROBUS_PINCTRL_UART 1
+#define MIKROBUS_PINCTRL_I2C 2
+#define MIKROBUS_PINCTRL_SPI 3
+
+enum mikrobus_property_type {
+ MIKROBUS_PROPERTY_TYPE_MIKROBUS = 0x00,
+ MIKROBUS_PROPERTY_TYPE_PROPERTY,
+ MIKROBUS_PROPERTY_TYPE_GPIO,
+ MIKROBUS_PROPERTY_TYPE_U8,
+ MIKROBUS_PROPERTY_TYPE_U16,
+ MIKROBUS_PROPERTY_TYPE_U32,
+ MIKROBUS_PROPERTY_TYPE_U64,
+};
+
+enum mikrobus_pin {
+ MIKROBUS_PIN_PWM = 0x00,
+ MIKROBUS_PIN_INT,
+ MIKROBUS_PIN_RX,
+ MIKROBUS_PIN_TX,
+ MIKROBUS_PIN_SCL,
+ MIKROBUS_PIN_SDA,
+ MIKROBUS_PIN_MOSI,
+ MIKROBUS_PIN_MISO,
+ MIKROBUS_PIN_SCK,
+ MIKROBUS_PIN_CS,
+ MIKROBUS_PIN_RST,
+ MIKROBUS_PIN_AN,
+ MIKROBUS_PORT_PIN_COUNT,
+};
+
+enum mikrobus_pin_state {
+ MIKROBUS_STATE_INPUT = 0x01,
+ MIKROBUS_STATE_OUTPUT_HIGH,
+ MIKROBUS_STATE_OUTPUT_LOW,
+ MIKROBUS_STATE_PWM,
+ MIKROBUS_STATE_SPI,
+ MIKROBUS_STATE_I2C,
+ MIKROBUS_STATE_UART,
+};
+
+/*
+ * board_device_info describes a single device on a mikrobus add-on
+ * board, an add-on board can present one or more device to the host
+ *
+ * @gpio_lookup: used to provide the GPIO lookup table for
+ * passing the named GPIOs to device drivers.
+ * @properties: used to provide the property_entry to pass named
+ * properties to device drivers, applicable only when driver uses
+ * device_property_read_* calls to fetch the properties.
+ * @num_gpio_resources: number of named gpio resources for the device,
+ * used mainly for gpiod_lookup_table memory allocation.
+ * @num_properties: number of custom properties for the device,
+ * used mainly for property_entry memory allocation.
+ * @protocol: used to know the type of the device and it should
+ * contain one of the values defined under 'enum greybus_class_type'
+ * under linux/greybus/greybus_manifest.h
+ * @reg: I2C address for the device, for devices on the SPI bus
+ * this field is the chip select address relative to the mikrobus
+ * port:0->device chip select connected to CS pin on mikroBUS port
+ * 1->device chip select connected to RST Pin on mikroBUS port
+ * @mode: SPI mode
+ * @max_speed_hz: SPI max speed(Hz)
+ * @drv_name: device_id to match with the driver
+ * @irq_type: type of IRQ trigger , match with defines in linux/interrupt.h
+ * @irq: irq number relative to the mikrobus port should contain one of the
+ * values defined under 'enum mikrobus_pin'
+ * @id: device id starting from 1
+ */
+struct board_device_info {
+ struct gpiod_lookup_table *gpio_lookup;
+ struct property_entry *properties;
+ struct list_head links;
+ unsigned short num_gpio_resources;
+ unsigned short num_properties;
+ unsigned short protocol;
+ unsigned short reg;
+ unsigned int mode;
+ void *dev_client;
+ u32 max_speed_hz;
+ char *drv_name;
+ int irq_type;
+ int irq;
+ int id;
+};
+
+/*
+ * addon_board_info describes a mikrobus add-on device the add-on
+ * board, an add-on board can present one or more device to the host
+ *
+ * @manifest_descs: list of manifest descriptors
+ * @devices: list of devices on the board
+ * @pin_state: the state of each pin on the mikrobus port required
+ * for the add-on board should contain one of the values defined under
+ * 'enum mikrobus_pin_state' restrictions are as per mikrobus standard
+ * specifications.
+ * @name: add-on board name
+ */
+struct addon_board_info {
+ struct list_head manifest_descs;
+ struct list_head devices;
+ u8 pin_state[MIKROBUS_PORT_PIN_COUNT];
+ char *name;
+};
+
+/*
+ * mikrobus_port describes the peripherals mapped to a mikrobus port.
+ *
+ * @chip_select: chip select number mapped to the SPI CS pin on the
+ * mikrobus port and the RST pin on the mikrobus port
+ * @board: pointer to the attached add-on board.
+ * @spi_ctrl: SPI controller attached to the mikrobus port.
+ * @i2c_adap: I2C adapter attached to the mikrobus port.
+ * @gpios: GPIOs attached to the mikrobus port.
+ * @pinctrl: pinctrl attached to the mikrobus port.
+ * @dev: device structure for the mikrobus port.
+ * @id: port id starting from 1
+ */
+struct mikrobus_port {
+ u32 chip_select[MIKROBUS_NUM_CS];
+ struct addon_board_info *board;
+ struct spi_controller *spi_ctrl;
+ struct i2c_adapter *i2c_adap;
+ struct gpio_descs *gpios;
+ struct pinctrl *pinctrl;
+ struct device dev;
+ int id;
+};
+
+#define to_mikrobus_port(d) container_of(d, struct mikrobus_port, dev)
+
+#endif /* __MIKROBUS_H */
diff --git a/drivers/misc/mikrobus/mikrobus_manifest.c b/drivers/misc/mikrobus/mikrobus_manifest.c
new file mode 100644
index 000000000000..5f30620277be
--- /dev/null
+++ b/drivers/misc/mikrobus/mikrobus_manifest.c
@@ -0,0 +1,503 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * mikroBUS manifest parsing, an
+ * extension to Greybus Manifest Parsing
+ * under drivers/greybus/manifest.c
+ *
+ * Copyright 2014-2015 Google Inc.
+ * Copyright 2014-2015 Linaro Ltd.
+ * Copyright 2024 Ayush Singh <ayushdevel1325@xxxxxxxxx>
+ */
+
+#define pr_fmt(fmt) "mikrobus_manifest:%s: " fmt, __func__
+
+#include "linux/gpio/machine.h"
+#include "linux/greybus/greybus_manifest.h"
+#include "linux/property.h"
+#include "mikrobus_manifest.h"
+
+struct manifest_desc {
+ struct list_head links;
+ size_t size;
+ void *data;
+ enum greybus_descriptor_type type;
+};
+
+static void manifest_descriptor_release_all(struct addon_board_info *board)
+{
+ struct manifest_desc *descriptor, *next;
+
+ list_for_each_entry_safe(descriptor, next, &board->manifest_descs,
+ links) {
+ list_del(&descriptor->links);
+ kfree(descriptor);
+ }
+}
+
+static int board_descriptor_add(struct addon_board_info *board,
+ struct greybus_descriptor *desc, size_t size)
+{
+ struct greybus_descriptor_header *desc_header = &desc->header;
+ struct manifest_desc *descriptor;
+ size_t desc_size, expected_size;
+
+ if (size < sizeof(*desc_header)) {
+ pr_err("short descriptor (%zu < %zu)", size,
+ sizeof(*desc_header));
+ return -EINVAL;
+ }
+
+ desc_size = le16_to_cpu(desc_header->size);
+ if (desc_size > size) {
+ pr_err("incorrect descriptor size (%zu != %zu)", size,
+ desc_size);
+ return -EINVAL;
+ }
+
+ expected_size = sizeof(*desc_header);
+ switch (desc_header->type) {
+ case GREYBUS_TYPE_STRING:
+ expected_size += sizeof(struct greybus_descriptor_string);
+ expected_size += desc->string.length;
+ expected_size = ALIGN(expected_size, 4);
+ break;
+ case GREYBUS_TYPE_PROPERTY:
+ expected_size += sizeof(struct greybus_descriptor_property);
+ expected_size += desc->property.length;
+ expected_size = ALIGN(expected_size, 4);
+ break;
+ case GREYBUS_TYPE_DEVICE:
+ expected_size += sizeof(struct greybus_descriptor_device);
+ break;
+ case GREYBUS_TYPE_MIKROBUS:
+ expected_size += sizeof(struct greybus_descriptor_mikrobus);
+ break;
+ case GREYBUS_TYPE_INTERFACE:
+ expected_size += sizeof(struct greybus_descriptor_interface);
+ break;
+ case GREYBUS_TYPE_CPORT:
+ expected_size += sizeof(struct greybus_descriptor_cport);
+ break;
+ case GREYBUS_TYPE_BUNDLE:
+ expected_size += sizeof(struct greybus_descriptor_bundle);
+ break;
+ case GREYBUS_TYPE_INVALID:
+ default:
+ pr_err("invalid descriptor type %d", desc_header->type);
+ return -EINVAL;
+ }
+
+ descriptor = kzalloc(sizeof(*descriptor), GFP_KERNEL);
+ if (!descriptor)
+ return -ENOMEM;
+
+ descriptor->size = desc_size;
+ descriptor->data = (char *)desc + sizeof(*desc_header);
+ descriptor->type = desc_header->type;
+ list_add_tail(&descriptor->links, &board->manifest_descs);
+
+ return desc_size;
+}
+
+static char *mikrobus_string_get(struct addon_board_info *board, u8 string_id)
+{
+ struct greybus_descriptor_string *desc_string;
+ struct manifest_desc *descriptor;
+ bool found = false;
+ char *string;
+
+ if (!string_id)
+ return NULL;
+
+ list_for_each_entry(descriptor, &board->manifest_descs, links) {
+ if (descriptor->type != GREYBUS_TYPE_STRING)
+ continue;
+
+ desc_string = descriptor->data;
+ if (desc_string->id == string_id) {
+ found = true;
+ break;
+ }
+ }
+
+ if (!found)
+ return ERR_PTR(-ENOENT);
+
+ string = kmemdup(&desc_string->string, desc_string->length + 1,
+ GFP_KERNEL);
+ if (!string)
+ return ERR_PTR(-ENOMEM);
+
+ string[desc_string->length] = '\0';
+
+ return string;
+}
+
+static void mikrobus_state_get(struct addon_board_info *board)
+{
+ struct greybus_descriptor_mikrobus *mikrobus;
+ struct greybus_descriptor_interface *interface;
+ struct manifest_desc *descriptor;
+ bool found = false;
+ size_t i;
+
+ list_for_each_entry(descriptor, &board->manifest_descs, links) {
+ if (descriptor->type == GREYBUS_TYPE_MIKROBUS) {
+ mikrobus = descriptor->data;
+ found = true;
+ break;
+ }
+ }
+
+ if (!found) {
+ pr_err("mikrobus descriptor not found");
+ return;
+ }
+
+ for (i = 0; i < MIKROBUS_PORT_PIN_COUNT; i++)
+ board->pin_state[i] = mikrobus->pin_state[i];
+
+ found = false;
+ list_for_each_entry(descriptor, &board->manifest_descs, links) {
+ if (descriptor->type == GREYBUS_TYPE_INTERFACE) {
+ interface = descriptor->data;
+ found = true;
+ break;
+ }
+ }
+
+ if (!found) {
+ pr_err("interface descriptor not found");
+ return;
+ }
+
+ board->name = mikrobus_string_get(board, interface->product_stringid);
+}
+
+static struct property_entry *
+mikrobus_property_entry_get(struct addon_board_info *board, u8 *prop_link,
+ int num_properties)
+{
+ struct greybus_descriptor_property *desc_property;
+ struct manifest_desc *descriptor;
+ struct property_entry *properties;
+ bool found = false;
+ char *prop_name;
+ int i, ret;
+ u64 *val_u64;
+ u32 *val_u32;
+ u16 *val_u16;
+ u8 *val_u8;
+
+ properties = kcalloc(num_properties, sizeof(*properties), GFP_KERNEL);
+ if (!properties)
+ return ERR_PTR(-ENOMEM);
+
+ for (i = 0; i < num_properties; i++) {
+ list_for_each_entry(descriptor, &board->manifest_descs, links) {
+ if (descriptor->type != GREYBUS_TYPE_PROPERTY)
+ continue;
+
+ desc_property = descriptor->data;
+ if (desc_property->id == prop_link[i]) {
+ found = true;
+ break;
+ }
+ }
+
+ if (!found) {
+ ret = -ENOENT;
+ goto early_exit;
+ }
+
+ prop_name = mikrobus_string_get(
+ board, desc_property->propname_stringid);
+ if (!prop_name) {
+ ret = -ENOENT;
+ goto early_exit;
+ }
+
+ switch (desc_property->type) {
+ case MIKROBUS_PROPERTY_TYPE_U8:
+ val_u8 = kmemdup(&desc_property->value,
+ (desc_property->length) * sizeof(u8),
+ GFP_KERNEL);
+ if (desc_property->length == 1)
+ properties[i] =
+ PROPERTY_ENTRY_U8(prop_name, *val_u8);
+ else
+ properties[i] = PROPERTY_ENTRY_U8_ARRAY_LEN(
+ prop_name, (void *)desc_property->value,
+ desc_property->length);
+ break;
+ case MIKROBUS_PROPERTY_TYPE_U16:
+ val_u16 = kmemdup(&desc_property->value,
+ (desc_property->length) * sizeof(u16),
+ GFP_KERNEL);
+ if (desc_property->length == 1)
+ properties[i] =
+ PROPERTY_ENTRY_U16(prop_name, *val_u16);
+ else
+ properties[i] = PROPERTY_ENTRY_U16_ARRAY_LEN(
+ prop_name, (void *)desc_property->value,
+ desc_property->length);
+ break;
+ case MIKROBUS_PROPERTY_TYPE_U32:
+ val_u32 = kmemdup(&desc_property->value,
+ (desc_property->length) * sizeof(u32),
+ GFP_KERNEL);
+ if (desc_property->length == 1)
+ properties[i] =
+ PROPERTY_ENTRY_U32(prop_name, *val_u32);
+ else
+ properties[i] = PROPERTY_ENTRY_U32_ARRAY_LEN(
+ prop_name, (void *)desc_property->value,
+ desc_property->length);
+ break;
+ case MIKROBUS_PROPERTY_TYPE_U64:
+ val_u64 = kmemdup(&desc_property->value,
+ (desc_property->length) * sizeof(u64),
+ GFP_KERNEL);
+ if (desc_property->length == 1)
+ properties[i] =
+ PROPERTY_ENTRY_U64(prop_name, *val_u64);
+ else
+ properties[i] = PROPERTY_ENTRY_U64_ARRAY_LEN(
+ prop_name, (void *)desc_property->value,
+ desc_property->length);
+ break;
+ default:
+ ret = -EINVAL;
+ goto early_exit;
+ }
+ }
+ return properties;
+
+early_exit:
+ kfree(properties);
+ return ERR_PTR(ret);
+}
+
+static u8 *mikrobus_property_link_get(struct addon_board_info *board,
+ u8 prop_id,
+ struct board_device_info *board_dev,
+ u8 prop_type)
+{
+ struct greybus_descriptor_property *desc_property;
+ struct manifest_desc *descriptor;
+ bool found = false;
+ u8 *val_u8;
+
+ if (!prop_id)
+ return NULL;
+
+ list_for_each_entry(descriptor, &board->manifest_descs, links) {
+ if (descriptor->type != GREYBUS_TYPE_PROPERTY)
+ continue;
+
+ desc_property = descriptor->data;
+ if (desc_property->id == prop_id &&
+ desc_property->type == prop_type) {
+ found = true;
+ break;
+ }
+ }
+
+ if (!found)
+ return ERR_PTR(-ENOENT);
+
+ val_u8 = kmemdup(&desc_property->value, desc_property->length,
+ GFP_KERNEL);
+ if (prop_type == MIKROBUS_PROPERTY_TYPE_GPIO)
+ board_dev->num_gpio_resources = desc_property->length;
+ else if (prop_type == MIKROBUS_PROPERTY_TYPE_PROPERTY)
+ board_dev->num_properties = desc_property->length;
+
+ return val_u8;
+}
+
+static int
+mikrobus_manifest_attach_device(struct addon_board_info *board,
+ struct greybus_descriptor_device *dev_desc)
+{
+ struct greybus_descriptor_property *desc_property;
+ u8 *gpio_desc_link, *prop_link, *gpioval;
+ struct board_device_info *board_dev;
+ struct gpiod_lookup_table *lookup;
+ struct manifest_desc *descriptor;
+ int ret, i;
+
+ board_dev = kzalloc(sizeof(*board_dev), GFP_KERNEL);
+ if (!board_dev)
+ return -ENOMEM;
+
+ board_dev->id = dev_desc->id;
+ board_dev->drv_name =
+ mikrobus_string_get(board, dev_desc->driver_stringid);
+ if (!board_dev->drv_name) {
+ ret = -ENOENT;
+ goto err_free_board_dev;
+ }
+
+ board_dev->protocol = dev_desc->protocol;
+ board_dev->reg = dev_desc->reg;
+ board_dev->irq = dev_desc->irq;
+ board_dev->irq_type = dev_desc->irq_type;
+ board_dev->max_speed_hz = le32_to_cpu(dev_desc->max_speed_hz);
+ board_dev->mode = dev_desc->mode;
+ pr_info("parsed device %d, driver=%s", board_dev->id,
+ board_dev->drv_name);
+
+ if (dev_desc->prop_link > 0) {
+ prop_link = mikrobus_property_link_get(
+ board, dev_desc->prop_link, board_dev,
+ MIKROBUS_PROPERTY_TYPE_PROPERTY);
+ if (!prop_link) {
+ ret = -ENOENT;
+ goto err_free_board_dev;
+ }
+
+ pr_info("device %d, number of properties=%d", board_dev->id,
+ board_dev->num_properties);
+ board_dev->properties = mikrobus_property_entry_get(
+ board, prop_link, board_dev->num_properties);
+ }
+
+ if (dev_desc->gpio_link > 0) {
+ gpio_desc_link = mikrobus_property_link_get(
+ board, dev_desc->gpio_link, board_dev,
+ MIKROBUS_PROPERTY_TYPE_GPIO);
+ if (!gpio_desc_link) {
+ ret = -ENOENT;
+ goto err_free_board_dev;
+ }
+
+ pr_info("device %d, number of gpio resource=%d", board_dev->id,
+ board_dev->num_gpio_resources);
+ lookup = kzalloc(struct_size(lookup, table,
+ board_dev->num_gpio_resources),
+ GFP_KERNEL);
+ if (!lookup) {
+ ret = -ENOMEM;
+ goto err_free_board_dev;
+ }
+
+ for (i = 0; i < board_dev->num_gpio_resources; i++) {
+ list_for_each_entry(descriptor, &board->manifest_descs,
+ links) {
+ if (descriptor->type != GREYBUS_TYPE_PROPERTY)
+ continue;
+
+ desc_property = descriptor->data;
+ if (desc_property->id == gpio_desc_link[i]) {
+ gpioval = desc_property->value;
+ lookup->table[i].chip_hwnum =
+ gpioval[0];
+ lookup->table[i].flags = gpioval[1];
+ lookup->table[i]
+ .con_id = mikrobus_string_get(
+ board,
+ desc_property
+ ->propname_stringid);
+ break;
+ }
+ }
+ }
+ board_dev->gpio_lookup = lookup;
+ }
+
+ list_add_tail(&board_dev->links, &board->devices);
+ return 0;
+
+err_free_board_dev:
+ kfree(board_dev);
+ return ret;
+}
+
+static int mikrobus_manifest_parse_devices(struct addon_board_info *board)
+{
+ struct greybus_descriptor_device *desc_device;
+ struct manifest_desc *desc, *next;
+ int ret, devcount = 0;
+
+ list_for_each_entry_safe(desc, next, &board->manifest_descs, links) {
+ if (desc->type != GREYBUS_TYPE_DEVICE)
+ continue;
+
+ desc_device = desc->data;
+ ret = mikrobus_manifest_attach_device(board, desc_device);
+ devcount++;
+ }
+
+ return devcount;
+}
+
+static size_t mikrobus_manifest_header_validate(void *data, size_t size)
+{
+ struct greybus_manifest_header *header = data;
+ u16 manifest_size = le16_to_cpu(header->size);
+
+ if (manifest_size < sizeof(*header)) {
+ pr_err("short manifest (%zu < %zu)", size, sizeof(*header));
+ return -EINVAL;
+ }
+
+ if (header->version_major > MIKROBUS_VERSION_MAJOR) {
+ pr_err("manifest version too new (%u.%u > %u.%u)",
+ header->version_major, header->version_minor,
+ MIKROBUS_VERSION_MAJOR, MIKROBUS_VERSION_MINOR);
+ return -EINVAL;
+ }
+
+ return manifest_size;
+}
+
+int mikrobus_manifest_parse(struct addon_board_info *board, void *data,
+ size_t size)
+{
+ struct greybus_manifest_header *header;
+ struct greybus_manifest *manifest;
+ struct greybus_descriptor *desc;
+ int dev_count, desc_size, ret;
+ u16 manifest_size;
+
+ if (size < sizeof(*header)) {
+ pr_err("short manifest (%zu < %zu)", size, sizeof(*header));
+ return -EINVAL;
+ }
+
+ ret = mikrobus_manifest_header_validate(data, size);
+ if (ret < 0) {
+ pr_err("invalid manifest header: %u", manifest_size);
+ return ret;
+ }
+
+ manifest = data;
+ manifest_size = ret;
+
+ if (manifest_size != size) {
+ pr_err("invalid manifest size(%zu < %u)", size, manifest_size);
+ return -EINVAL;
+ }
+
+ desc = manifest->descriptors;
+ size -= sizeof(*header);
+ while (size) {
+ desc_size = board_descriptor_add(board, desc, size);
+ if (desc_size < 0) {
+ pr_err("invalid manifest descriptor, size: %u",
+ desc_size);
+ return -EINVAL;
+ }
+
+ desc = (void *)desc + desc_size;
+ size -= desc_size;
+ }
+
+ mikrobus_state_get(board);
+ dev_count = mikrobus_manifest_parse_devices(board);
+ pr_info("%s manifest parsed with %d devices", board->name, dev_count);
+ manifest_descriptor_release_all(board);
+
+ return dev_count;
+}
diff --git a/drivers/misc/mikrobus/mikrobus_manifest.h b/drivers/misc/mikrobus/mikrobus_manifest.h
new file mode 100644
index 000000000000..39ae53a25fc4
--- /dev/null
+++ b/drivers/misc/mikrobus/mikrobus_manifest.h
@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * mikroBUS manifest definition
+ * extension to Greybus Manifest Definition
+ *
+ * Copyright 2014-2015 Google Inc.
+ * Copyright 2014-2015 Linaro Ltd.
+ *
+ * Released under the GPLv2 and BSD licenses.
+ */
+
+#ifndef __MIKROBUS_MANIFEST_H
+#define __MIKROBUS_MANIFEST_H
+
+#include "mikrobus_core.h"
+
+/*
+ * mikrobus_manifest_header - parse mikroBUS manifest
+ *
+ * @info: addon board info structure to populate with parsed information
+ * @data: pointer to the manifest blob
+ * @size: size of the manifest blob
+ *
+ * returns: number of devices on success, negative error code on failure
+ */
+int mikrobus_manifest_parse(struct addon_board_info *info, void *data,
+ size_t size);
+
+#endif /* __MIKROBUS_MANIFEST_H */
--
2.44.0