pinctrl: add pin control uclass support

This creates a new framework for handling of pin control devices,
i.e. devices that control different aspects of package pins.

This uclass handles pinmuxing and pin configuration; pinmuxing
controls switching among silicon blocks that share certain physical
pins, pin configuration handles electronic properties such as pin-
biasing, load capacitance etc.

This framework can support the same device tree bindings, but if you
do not need full interface support, you can disable some features to
reduce memory foot print.  Typically around 1.5KB is necessary to
include full-featured uclass support on ARM board (CONFIG_PINCTRL +
CONFIG_PINCTRL_FULL + CONFIG_PINCTRL_GENERIC + CONFIG_PINCTRL_PINMUX),
for example.

We are often limited on code size for SPL.  Besides, we still have
many boards that do not support device tree configuration.  The full
pinctrl, which requires OF_CONTROL, does not make sense for those
boards.  So, this framework also has a Do-It-Yourself (let's say
simple pinctrl) interface.  With CONFIG_PINCTRL_FULL disabled, the
uclass itself provides no systematic mechanism for identifying the
peripheral device, applying pinctrl settings, etc.  They must be
done in each low-level driver.  In return, you can save much memory
footprint and it might be useful especially for SPL.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Simon Glass <sjg@chromium.org>

drivers/Kconfig

@@ -40,6 +40,8 @@ source "drivers/pci/Kconfig"
 
 source "drivers/pcmcia/Kconfig"
 
+source "drivers/pinctrl/Kconfig"
+
 source "drivers/power/Kconfig"
 
 source "drivers/ram/Kconfig"

drivers/Makefile

@@ -1,6 +1,7 @@
 obj-$(CONFIG_$(SPL_)DM)		+= core/
 obj-$(CONFIG_$(SPL_)CLK)	+= clk/
 obj-$(CONFIG_$(SPL_)LED)	+= led/
+obj-$(CONFIG_$(SPL_)PINCTRL)	+= pinctrl/
 obj-$(CONFIG_$(SPL_)RAM)	+= ram/
 
 ifdef CONFIG_SPL_BUILD

drivers/core/device.c

@@ -15,6 +15,7 @@
 #include <dm/device.h>
 #include <dm/device-internal.h>
 #include <dm/lists.h>
+#include <dm/pinctrl.h>
 #include <dm/platdata.h>
 #include <dm/uclass.h>
 #include <dm/uclass-internal.h>
@@ -286,6 +287,9 @@ int device_probe_child(struct udevice *dev, void *parent_priv)
 
 	dev->flags |= DM_FLAG_ACTIVATED;
 
+	/* continue regardless of the result of pinctrl */
+	pinctrl_select_state(dev, "default");
+
 	ret = uclass_pre_probe_device(dev);
 	if (ret)
 		goto fail;

drivers/pinctrl/Kconfig

@@ -0,0 +1,101 @@
+#
+# PINCTRL infrastructure and drivers
+#
+
+menu "Pin controllers"
+
+config PINCTRL
+	bool "Support pin controllers"
+	depends on DM
+	help
+	  This enables the basic support for pinctrl framework.  You may want
+	  to enable some more options depending on what you want to do.
+
+config PINCTRL_FULL
+	bool "Support full pin controllers"
+	depends on PINCTRL && OF_CONTROL
+	default y
+	help
+	  This provides Linux-compatible device tree interface for the pinctrl
+	  subsystem.  This feature depends on device tree configuration because
+	  it parses a device tree to look for the pinctrl device which the
+	  peripheral device is associated with.
+
+	  If this option is disabled (it is the only possible choice for non-DT
+	  boards), the pinctrl core provides no systematic mechanism for
+	  identifying peripheral devices, applying needed pinctrl settings.
+	  It is totally up to the implementation of each low-level driver.
+	  You can save memory footprint in return for some limitations.
+
+config PINCTRL_GENERIC
+	bool "Support generic pin controllers"
+	depends on PINCTRL_FULL
+	default y
+	help
+	  Say Y here if you want to use the pinctrl subsystem through the
+	  generic DT interface.  If enabled, some functions become available
+	  to parse common properties such as "pins", "groups", "functions" and
+	  some pin configuration parameters.  It would be easier if you only
+	  need the generic DT interface for pin muxing and pin configuration.
+	  If you need to handle vendor-specific DT properties, you can disable
+	  this option and implement your own set_state callback in the pinctrl
+	  operations.
+
+config PINMUX
+	bool "Support pin multiplexing controllers"
+	depends on PINCTRL_GENERIC
+	default y
+	help
+	  This option enables pin multiplexing through the generic pinctrl
+	  framework.
+
+config PINCONF
+	bool "Support pin configuration controllers"
+	depends on PINCTRL_GENERIC
+	help
+	  This option enables pin configuration through the generic pinctrl
+	  framework.
+
+config SPL_PINCTRL
+	bool "Support pin controlloers in SPL"
+	depends on SPL && SPL_DM
+	help
+	  This option is an SPL-variant of the PINCTRL option.
+	  See the help of PINCTRL for details.
+
+config SPL_PINCTRL_FULL
+	bool "Support full pin controllers in SPL"
+	depends on SPL_PINCTRL && SPL_OF_CONTROL
+	default y
+	help
+	  This option is an SPL-variant of the PINCTRL_FULL option.
+	  See the help of PINCTRL_FULL for details.
+
+config SPL_PINCTRL_GENERIC
+	bool "Support generic pin controllers in SPL"
+	depends on SPL_PINCTRL_FULL
+	default y
+	help
+	  This option is an SPL-variant of the PINCTRL_GENERIC option.
+	  See the help of PINCTRL_GENERIC for details.
+
+config SPL_PINMUX
+	bool "Support pin multiplexing controllers in SPL"
+	depends on SPL_PINCTRL_GENERIC
+	default y
+	help
+	  This option is an SPL-variant of the PINMUX option.
+	  See the help of PINMUX for details.
+
+config SPL_PINCONF
+	bool "Support pin configuration controllers in SPL"
+	depends on SPL_PINCTRL_GENERIC
+	help
+	  This option is an SPL-variant of the PINCONF option.
+	  See the help of PINCONF for details.
+
+if PINCTRL || SPL_PINCTRL
+
+endif
+
+endmenu

drivers/pinctrl/Makefile

@@ -0,0 +1,2 @@
+obj-y					+= pinctrl-uclass.o
+obj-$(CONFIG_$(SPL_)PINCTRL_GENERIC)	+= pinctrl-generic.o

drivers/pinctrl/pinctrl-generic.c

@@ -0,0 +1,359 @@
+/*
+ * Copyright (C) 2015  Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <linux/compat.h>
+#include <dm/device.h>
+#include <dm/pinctrl.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/**
+ * pinctrl_pin_name_to_selector() - return the pin selector for a pin
+ *
+ * @dev: pin controller device
+ * @pin: the pin name to look up
+ * @return: pin selector, or negative error code on failure
+ */
+static int pinctrl_pin_name_to_selector(struct udevice *dev, const char *pin)
+{
+	const struct pinctrl_ops *ops = pinctrl_get_ops(dev);
+	unsigned npins, selector;
+
+	if (!ops->get_pins_count || !ops->get_pin_name) {
+		dev_dbg(dev, "get_pins_count or get_pin_name missing\n");
+		return -ENOSYS;
+	}
+
+	npins = ops->get_pins_count(dev);
+
+	/* See if this pctldev has this pin */
+	for (selector = 0; selector < npins; selector++) {
+		const char *pname = ops->get_pin_name(dev, selector);
+
+		if (!strcmp(pin, pname))
+			return selector;
+	}
+
+	return -ENOSYS;
+}
+
+/**
+ * pinctrl_group_name_to_selector() - return the group selector for a group
+ *
+ * @dev: pin controller device
+ * @group: the pin group name to look up
+ * @return: pin group selector, or negative error code on failure
+ */
+static int pinctrl_group_name_to_selector(struct udevice *dev,
+					  const char *group)
+{
+	const struct pinctrl_ops *ops = pinctrl_get_ops(dev);
+	unsigned ngroups, selector;
+
+	if (!ops->get_groups_count || !ops->get_group_name) {
+		dev_dbg(dev, "get_groups_count or get_group_name missing\n");
+		return -ENOSYS;
+	}
+
+	ngroups = ops->get_groups_count(dev);
+
+	/* See if this pctldev has this group */
+	for (selector = 0; selector < ngroups; selector++) {
+		const char *gname = ops->get_group_name(dev, selector);
+
+		if (!strcmp(group, gname))
+			return selector;
+	}
+
+	return -ENOSYS;
+}
+
+#if CONFIG_IS_ENABLED(PINMUX)
+/**
+ * pinmux_func_name_to_selector() - return the function selector for a function
+ *
+ * @dev: pin controller device
+ * @function: the function name to look up
+ * @return: function selector, or negative error code on failure
+ */
+static int pinmux_func_name_to_selector(struct udevice *dev,
+					const char *function)
+{
+	const struct pinctrl_ops *ops = pinctrl_get_ops(dev);
+	unsigned nfuncs, selector = 0;
+
+	if (!ops->get_functions_count || !ops->get_function_name) {
+		dev_dbg(dev,
+			"get_functions_count or get_function_name missing\n");
+		return -ENOSYS;
+	}
+
+	nfuncs = ops->get_functions_count(dev);
+
+	/* See if this pctldev has this function */
+	for (selector = 0; selector < nfuncs; selector++) {
+		const char *fname = ops->get_function_name(dev, selector);
+
+		if (!strcmp(function, fname))
+			return selector;
+	}
+
+	return -ENOSYS;
+}
+
+/**
+ * pinmux_enable_setting() - enable pin-mux setting for a certain pin/group
+ *
+ * @dev: pin controller device
+ * @is_group: target of operation (true: pin group, false: pin)
+ * @selector: pin selector or group selector, depending on @is_group
+ * @func_selector: function selector
+ * @return: 0 on success, or negative error code on failure
+ */
+static int pinmux_enable_setting(struct udevice *dev, bool is_group,
+				 unsigned selector, unsigned func_selector)
+{
+	const struct pinctrl_ops *ops = pinctrl_get_ops(dev);
+
+	if (is_group) {
+		if (!ops->pinmux_group_set) {
+			dev_dbg(dev, "pinmux_group_set op missing\n");
+			return -ENOSYS;
+		}
+
+		return ops->pinmux_group_set(dev, selector, func_selector);
+	} else {
+		if (!ops->pinmux_set) {
+			dev_dbg(dev, "pinmux_set op missing\n");
+			return -ENOSYS;
+		}
+		return ops->pinmux_set(dev, selector, func_selector);
+	}
+}
+#else
+static int pinmux_func_name_to_selector(struct udevice *dev,
+					const char *function)
+{
+	return 0;
+}
+
+static int pinmux_enable_setting(struct udevice *dev, bool is_group,
+				 unsigned selector, unsigned func_selector)
+{
+	return 0;
+}
+#endif
+
+#if CONFIG_IS_ENABLED(PINCONF)
+/**
+ * pinconf_prop_name_to_param() - return parameter ID for a property name
+ *
+ * @dev: pin controller device
+ * @property: property name in DTS, such as "bias-pull-up", "slew-rate", etc.
+ * @default_value: return default value in case no value is specified in DTS
+ * @return: return pamater ID, or negative error code on failure
+ */
+static int pinconf_prop_name_to_param(struct udevice *dev,
+				      const char *property, u32 *default_value)
+{
+	const struct pinctrl_ops *ops = pinctrl_get_ops(dev);
+	const struct pinconf_param *p, *end;
+
+	if (!ops->pinconf_num_params || !ops->pinconf_params) {
+		dev_dbg(dev, "pinconf_num_params or pinconf_params missing\n");
+		return -ENOSYS;
+	}
+
+	p = ops->pinconf_params;
+	end = p + ops->pinconf_num_params;
+
+	/* See if this pctldev supports this parameter */
+	for (; p < end; p++) {
+		if (!strcmp(property, p->property)) {
+			*default_value = p->default_value;
+			return p->param;
+		}
+	}
+
+	return -ENOSYS;
+}
+
+/**
+ * pinconf_enable_setting() - apply pin configuration for a certain pin/group
+ *
+ * @dev: pin controller device
+ * @is_group: target of operation (true: pin group, false: pin)
+ * @selector: pin selector or group selector, depending on @is_group
+ * @param: configuration paramter
+ * @argument: argument taken by some configuration parameters
+ * @return: 0 on success, or negative error code on failure
+ */
+static int pinconf_enable_setting(struct udevice *dev, bool is_group,
+				  unsigned selector, unsigned param,
+				  u32 argument)
+{
+	const struct pinctrl_ops *ops = pinctrl_get_ops(dev);
+
+	if (is_group) {
+		if (!ops->pinconf_group_set) {
+			dev_dbg(dev, "pinconf_group_set op missing\n");
+			return -ENOSYS;
+		}
+
+		return ops->pinconf_group_set(dev, selector, param,
+					      argument);
+	} else {
+		if (!ops->pinconf_set) {
+			dev_dbg(dev, "pinconf_set op missing\n");
+			return -ENOSYS;
+		}
+		return ops->pinconf_set(dev, selector, param, argument);
+	}
+}
+#else
+static int pinconf_prop_name_to_param(struct udevice *dev,
+				      const char *property, u32 *default_value)
+{
+	return -ENOSYS;
+}
+
+static int pinconf_enable_setting(struct udevice *dev, bool is_group,
+				  unsigned selector, unsigned param,
+				  u32 argument)
+{
+	return 0;
+}
+#endif
+
+/**
+ * pinctrl_generic_set_state_one() - set state for a certain pin/group
+ * Apply all pin multiplexing and pin configurations specified by @config
+ * for a given pin or pin group.
+ *
+ * @dev: pin controller device
+ * @config: pseudo device pointing to config node
+ * @is_group: target of operation (true: pin group, false: pin)
+ * @selector: pin selector or group selector, depending on @is_group
+ * @return: 0 on success, or negative error code on failure
+ */
+static int pinctrl_generic_set_state_one(struct udevice *dev,
+					 struct udevice *config,
+					 bool is_group, unsigned selector)
+{
+	const void *fdt = gd->fdt_blob;
+	int node_offset = config->of_offset;
+	const char *propname;
+	const void *value;
+	int prop_offset, len, func_selector, param, ret;
+	u32 arg, default_val;
+
+	for (prop_offset = fdt_first_property_offset(fdt, node_offset);
+	     prop_offset > 0;
+	     prop_offset = fdt_next_property_offset(fdt, prop_offset)) {
+		value = fdt_getprop_by_offset(fdt, prop_offset,
+					      &propname, &len);
+		if (!value)
+			return -EINVAL;
+
+		if (!strcmp(propname, "function")) {
+			func_selector = pinmux_func_name_to_selector(dev,
+								     value);
+			if (func_selector < 0)
+				return func_selector;
+			ret = pinmux_enable_setting(dev, is_group,
+						    selector,
+						    func_selector);
+		} else {
+			param = pinconf_prop_name_to_param(dev, propname,
+							   &default_val);
+			if (param < 0)
+				continue; /* just skip unknown properties */
+
+			if (len >= sizeof(fdt32_t))
+				arg = fdt32_to_cpu(*(fdt32_t *)value);
+			else
+				arg = default_val;
+
+			ret = pinconf_enable_setting(dev, is_group,
+						     selector, param, arg);
+		}
+
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * pinctrl_generic_set_state_subnode() - apply all settings in config node
+ *
+ * @dev: pin controller device
+ * @config: pseudo device pointing to config node
+ * @return: 0 on success, or negative error code on failure
+ */
+static int pinctrl_generic_set_state_subnode(struct udevice *dev,
+					     struct udevice *config)
+{
+	const void *fdt = gd->fdt_blob;
+	int node = config->of_offset;
+	const char *subnode_target_type = "pins";
+	bool is_group = false;
+	const char *name;
+	int strings_count, selector, i, ret;
+
+	strings_count = fdt_count_strings(fdt, node, subnode_target_type);
+	if (strings_count < 0) {
+		subnode_target_type = "groups";
+		is_group = true;
+		strings_count = fdt_count_strings(fdt, node,
+						  subnode_target_type);
+		if (strings_count < 0)
+			return -EINVAL;
+	}
+
+	for (i = 0; i < strings_count; i++) {
+		ret = fdt_get_string_index(fdt, node, subnode_target_type,
+					   i, &name);
+		if (ret < 0)
+			return -EINVAL;
+
+		if (is_group)
+			selector = pinctrl_group_name_to_selector(dev, name);
+		else
+			selector = pinctrl_pin_name_to_selector(dev, name);
+		if (selector < 0)
+			return selector;
+
+		ret = pinctrl_generic_set_state_one(dev, config,
+						    is_group, selector);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+int pinctrl_generic_set_state(struct udevice *dev, struct udevice *config)
+{
+	struct udevice *child;
+	int ret;
+
+	ret = pinctrl_generic_set_state_subnode(dev, config);
+	if (ret)
+		return ret;
+
+	for (device_find_first_child(config, &child);
+	     child;
+	     device_find_next_child(&child)) {
+		ret = pinctrl_generic_set_state_subnode(dev, child);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}

drivers/pinctrl/pinctrl-uclass.c

@@ -0,0 +1,240 @@
+/*
+ * Copyright (C) 2015  Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <libfdt.h>
+#include <linux/err.h>
+#include <linux/list.h>
+#include <dm/device.h>
+#include <dm/lists.h>
+#include <dm/pinctrl.h>
+#include <dm/uclass.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+#if CONFIG_IS_ENABLED(PINCTRL_FULL)
+/**
+ * pinctrl_config_one() - apply pinctrl settings for a single node
+ *
+ * @config: pin configuration node
+ * @return: 0 on success, or negative error code on failure
+ */
+static int pinctrl_config_one(struct udevice *config)
+{
+	struct udevice *pctldev;
+	const struct pinctrl_ops *ops;
+
+	pctldev = config;
+	for (;;) {
+		pctldev = dev_get_parent(pctldev);
+		if (!pctldev) {
+			dev_err(config, "could not find pctldev\n");
+			return -EINVAL;
+		}
+		if (pctldev->uclass->uc_drv->id == UCLASS_PINCTRL)
+			break;
+	}
+
+	ops = pinctrl_get_ops(pctldev);
+	return ops->set_state(pctldev, config);
+}
+
+/**
+ * pinctrl_select_state_full() - full implementation of pinctrl_select_state
+ *
+ * @dev: peripheral device
+ * @statename: state name, like "default"
+ * @return: 0 on success, or negative error code on failure
+ */
+static int pinctrl_select_state_full(struct udevice *dev, const char *statename)
+{
+	const void *fdt = gd->fdt_blob;
+	int node = dev->of_offset;
+	char propname[32]; /* long enough */
+	const fdt32_t *list;
+	uint32_t phandle;
+	int config_node;
+	struct udevice *config;
+	int state, size, i, ret;
+
+	state = fdt_find_string(fdt, node, "pinctrl-names", statename);
+	if (state < 0) {
+		char *end;
+		/*
+		 * If statename is not found in "pinctrl-names",
+		 * assume statename is just the integer state ID.
+		 */
+		state = simple_strtoul(statename, &end, 10);
+		if (*end)
+			return -EINVAL;
+	}
+
+	snprintf(propname, sizeof(propname), "pinctrl-%d", state);
+	list = fdt_getprop(fdt, node, propname, &size);
+	if (!list)
+		return -EINVAL;
+
+	size /= sizeof(*list);
+	for (i = 0; i < size; i++) {
+		phandle = fdt32_to_cpu(*list++);
+
+		config_node = fdt_node_offset_by_phandle(fdt, phandle);
+		if (config_node < 0) {
+			dev_err(dev, "prop %s index %d invalid phandle\n",
+				propname, i);
+			return -EINVAL;
+		}
+		ret = uclass_get_device_by_of_offset(UCLASS_PINCONFIG,
+						     config_node, &config);
+		if (ret)
+			return ret;
+
+		ret = pinctrl_config_one(config);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+/**
+ * pinconfig_post-bind() - post binding for PINCONFIG uclass
+ * Recursively bind its children as pinconfig devices.
+ *
+ * @dev: pinconfig device
+ * @return: 0 on success, or negative error code on failure
+ */
+static int pinconfig_post_bind(struct udevice *dev)
+{
+	const void *fdt = gd->fdt_blob;
+	int offset = dev->of_offset;
+	const char *name;
+	int ret;
+
+	for (offset = fdt_first_subnode(fdt, offset);
+	     offset > 0;
+	     offset = fdt_next_subnode(fdt, offset)) {
+		/*
+		 * If this node has "compatible" property, this is not
+		 * a pin configuration node, but a normal device. skip.
+		 */
+		fdt_get_property(fdt, offset, "compatible", &ret);
+		if (ret >= 0)
+			continue;
+
+		if (ret != -FDT_ERR_NOTFOUND)
+			return ret;
+
+		name = fdt_get_name(fdt, offset, NULL);
+		if (!name)
+			return -EINVAL;
+		ret = device_bind_driver_to_node(dev, "pinconfig", name,
+						 offset, NULL);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+UCLASS_DRIVER(pinconfig) = {
+	.id = UCLASS_PINCONFIG,
+	.post_bind = pinconfig_post_bind,
+	.name = "pinconfig",
+};
+
+U_BOOT_DRIVER(pinconfig_generic) = {
+	.name = "pinconfig",
+	.id = UCLASS_PINCONFIG,
+};
+
+#else
+static int pinctrl_select_state_full(struct udevice *dev, const char *statename)
+{
+	return -ENODEV;
+}
+
+static int pinconfig_post_bind(struct udevice *dev)
+{
+	return 0;
+}
+#endif
+
+/**
+ * pinctrl_select_state_simple() - simple implementation of pinctrl_select_state
+ *
+ * @dev: peripheral device
+ * @return: 0 on success, or negative error code on failure
+ */
+static int pinctrl_select_state_simple(struct udevice *dev)
+{
+	struct udevice *pctldev;
+	struct pinctrl_ops *ops;
+	int ret;
+
+	/*
+	 * For simplicity, assume the first device of PINCTRL uclass
+	 * is the correct one.  This is most likely OK as there is
+	 * usually only one pinctrl device on the system.
+	 */
+	ret = uclass_get_device(UCLASS_PINCTRL, 0, &pctldev);
+	if (ret)
+		return ret;
+
+	ops = pinctrl_get_ops(pctldev);
+	if (!ops->set_state_simple) {
+		dev_dbg(dev, "set_state_simple op missing\n");
+		return -ENOSYS;
+	}
+
+	return ops->set_state_simple(pctldev, dev);
+}
+
+int pinctrl_select_state(struct udevice *dev, const char *statename)
+{
+	/*
+	 * Try full-implemented pinctrl first.
+	 * If it fails or is not implemented, try simple one.
+	 */
+	if (pinctrl_select_state_full(dev, statename))
+		return pinctrl_select_state_simple(dev);
+
+	return 0;
+}
+
+/**
+ * pinconfig_post-bind() - post binding for PINCTRL uclass
+ * Recursively bind child nodes as pinconfig devices in case of full pinctrl.
+ *
+ * @dev: pinctrl device
+ * @return: 0 on success, or negative error code on failure
+ */
+static int pinctrl_post_bind(struct udevice *dev)
+{
+	const struct pinctrl_ops *ops = pinctrl_get_ops(dev);
+
+	if (!ops) {
+		dev_dbg(dev, "ops is not set.  Do not bind.\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * If set_state callback is set, we assume this pinctrl driver is the
+	 * full implementation.  In this case, its child nodes should be bound
+	 * so that peripheral devices can easily search in parent devices
+	 * during later DT-parsing.
+	 */
+	if (ops->set_state)
+		return pinconfig_post_bind(dev);
+
+	return 0;
+}
+
+UCLASS_DRIVER(pinctrl) = {
+	.id = UCLASS_PINCTRL,
+	.post_bind = pinctrl_post_bind,
+	.name = "pinctrl",
+};

include/dm/pinctrl.h

@@ -0,0 +1,227 @@
+/*
+ * Copyright (C) 2015  Masahiro Yamada <yamada.masahiro@socionext.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef __PINCTRL_H
+#define __PINCTRL_H
+
+/**
+ * struct pinconf_param - pin config parameters
+ *
+ * @property: property name in DT nodes
+ * @param: ID for this config parameter
+ * @default_value: default value for this config parameter used in case
+ *	no value is specified in DT nodes
+ */
+struct pinconf_param {
+	const char * const property;
+	unsigned int param;
+	u32 default_value;
+};
+
+/**
+ * struct pinctrl_ops - pin control operations, to be implemented by
+ * pin controller drivers.
+ *
+ * The @set_state is the only mandatory operation.  You can implement your
+ * pinctrl driver with its own @set_state.  In this case, the other callbacks
+ * are not required.  Otherwise, generic pinctrl framework is also available;
+ * use pinctrl_generic_set_state for @set_state, and implement other operations
+ * depending on your necessity.
+ *
+ * @get_pins_count: return number of selectable named pins available
+ *	in this driver.  (necessary to parse "pins" property in DTS)
+ * @get_pin_name: return the pin name of the pin selector,
+ *	called by the core to figure out which pin it shall do
+ *	operations to.  (necessary to parse "pins" property in DTS)
+ * @get_groups_count: return number of selectable named groups available
+ *	in this driver.  (necessary to parse "groups" property in DTS)
+ * @get_group_name: return the group name of the group selector,
+ *	called by the core to figure out which pin group it shall do
+ *	operations to.  (necessary to parse "groups" property in DTS)
+ * @get_functions_count: return number of selectable named functions available
+ *	in this driver.  (necessary for pin-muxing)
+ * @get_function_name: return the function name of the muxing selector,
+ *	called by the core to figure out which mux setting it shall map a
+ *	certain device to.  (necessary for pin-muxing)
+ * @pinmux_set: enable a certain muxing function with a certain pin.
+ *	The @func_selector selects a certain function whereas @pin_selector
+ *	selects a certain pin to be used. On simple controllers one of them
+ *	may be ignored.  (necessary for pin-muxing against a single pin)
+ * @pinmux_group_set: enable a certain muxing function with a certain pin
+ *	group.  The @func_selector selects a certain function whereas
+ *	@group_selector selects a certain set of pins to be used. On simple
+ *	controllers one of them may be ignored.
+ *	(necessary for pin-muxing against a pin group)
+ * @pinconf_num_params: number of driver-specific parameters to be parsed
+ *	from device trees  (necessary for pin-configuration)
+ * @pinconf_params: list of driver_specific parameters to be parsed from
+ *	device trees  (necessary for pin-configuration)
+ * @pinconf_set: configure an individual pin with a given parameter.
+ *	(necessary for pin-configuration against a single pin)
+ * @pinconf_group_set: configure all pins in a group with a given parameter.
+ *	(necessary for pin-configuration against a pin group)
+ * @set_state: do pinctrl operations specified by @config, a pseudo device
+ *	pointing a config node. (necessary for pinctrl_full)
+ * @set_state_simple: do needed pinctrl operations for a peripherl @periph.
+ *	(necessary for pinctrl_simple)
+ */
+struct pinctrl_ops {
+	int (*get_pins_count)(struct udevice *dev);
+	const char *(*get_pin_name)(struct udevice *dev, unsigned selector);
+	int (*get_groups_count)(struct udevice *dev);
+	const char *(*get_group_name)(struct udevice *dev, unsigned selector);
+	int (*get_functions_count)(struct udevice *dev);
+	const char *(*get_function_name)(struct udevice *dev,
+					 unsigned selector);
+	int (*pinmux_set)(struct udevice *dev, unsigned pin_selector,
+			  unsigned func_selector);
+	int (*pinmux_group_set)(struct udevice *dev, unsigned group_selector,
+				unsigned func_selector);
+	unsigned int pinconf_num_params;
+	const struct pinconf_param *pinconf_params;
+	int (*pinconf_set)(struct udevice *dev, unsigned pin_selector,
+			   unsigned param, unsigned argument);
+	int (*pinconf_group_set)(struct udevice *dev, unsigned group_selector,
+				 unsigned param, unsigned argument);
+	int (*set_state)(struct udevice *dev, struct udevice *config);
+	int (*set_state_simple)(struct udevice *dev, struct udevice *periph);
+};
+
+#define pinctrl_get_ops(dev)	((struct pinctrl_ops *)(dev)->driver->ops)
+
+/**
+ * Generic pin configuration paramters
+ *
+ * @PIN_CONFIG_BIAS_DISABLE: disable any pin bias on the pin, a
+ *	transition from say pull-up to pull-down implies that you disable
+ *	pull-up in the process, this setting disables all biasing.
+ * @PIN_CONFIG_BIAS_HIGH_IMPEDANCE: the pin will be set to a high impedance
+ *	mode, also know as "third-state" (tristate) or "high-Z" or "floating".
+ *	On output pins this effectively disconnects the pin, which is useful
+ *	if for example some other pin is going to drive the signal connected
+ *	to it for a while. Pins used for input are usually always high
+ *	impedance.
+ * @PIN_CONFIG_BIAS_BUS_HOLD: the pin will be set to weakly latch so that it
+ *	weakly drives the last value on a tristate bus, also known as a "bus
+ *	holder", "bus keeper" or "repeater". This allows another device on the
+ *	bus to change the value by driving the bus high or low and switching to
+ *	tristate. The argument is ignored.
+ * @PIN_CONFIG_BIAS_PULL_UP: the pin will be pulled up (usually with high
+ *	impedance to VDD). If the argument is != 0 pull-up is enabled,
+ *	if it is 0, pull-up is total, i.e. the pin is connected to VDD.
+ * @PIN_CONFIG_BIAS_PULL_DOWN: the pin will be pulled down (usually with high
+ *	impedance to GROUND). If the argument is != 0 pull-down is enabled,
+ *	if it is 0, pull-down is total, i.e. the pin is connected to GROUND.
+ * @PIN_CONFIG_BIAS_PULL_PIN_DEFAULT: the pin will be pulled up or down based
+ *	on embedded knowledge of the controller hardware, like current mux
+ *	function. The pull direction and possibly strength too will normally
+ *	be decided completely inside the hardware block and not be readable
+ *	from the kernel side.
+ *	If the argument is != 0 pull up/down is enabled, if it is 0, the
+ *	configuration is ignored. The proper way to disable it is to use
+ *	@PIN_CONFIG_BIAS_DISABLE.
+ * @PIN_CONFIG_DRIVE_PUSH_PULL: the pin will be driven actively high and
+ *	low, this is the most typical case and is typically achieved with two
+ *	active transistors on the output. Setting this config will enable
+ *	push-pull mode, the argument is ignored.
+ * @PIN_CONFIG_DRIVE_OPEN_DRAIN: the pin will be driven with open drain (open
+ *	collector) which means it is usually wired with other output ports
+ *	which are then pulled up with an external resistor. Setting this
+ *	config will enable open drain mode, the argument is ignored.
+ * @PIN_CONFIG_DRIVE_OPEN_SOURCE: the pin will be driven with open source
+ *	(open emitter). Setting this config will enable open source mode, the
+ *	argument is ignored.
+ * @PIN_CONFIG_DRIVE_STRENGTH: the pin will sink or source at most the current
+ *	passed as argument. The argument is in mA.
+ * @PIN_CONFIG_INPUT_ENABLE: enable the pin's input.  Note that this does not
+ *	affect the pin's ability to drive output.  1 enables input, 0 disables
+ *	input.
+ * @PIN_CONFIG_INPUT_SCHMITT_ENABLE: control schmitt-trigger mode on the pin.
+ *      If the argument != 0, schmitt-trigger mode is enabled. If it's 0,
+ *      schmitt-trigger mode is disabled.
+ * @PIN_CONFIG_INPUT_SCHMITT: this will configure an input pin to run in
+ *	schmitt-trigger mode. If the schmitt-trigger has adjustable hysteresis,
+ *	the threshold value is given on a custom format as argument when
+ *	setting pins to this mode.
+ * @PIN_CONFIG_INPUT_DEBOUNCE: this will configure the pin to debounce mode,
+ *	which means it will wait for signals to settle when reading inputs. The
+ *	argument gives the debounce time in usecs. Setting the
+ *	argument to zero turns debouncing off.
+ * @PIN_CONFIG_POWER_SOURCE: if the pin can select between different power
+ *	supplies, the argument to this parameter (on a custom format) tells
+ *	the driver which alternative power source to use.
+ * @PIN_CONFIG_SLEW_RATE: if the pin can select slew rate, the argument to
+ *	this parameter (on a custom format) tells the driver which alternative
+ *	slew rate to use.
+ * @PIN_CONFIG_LOW_POWER_MODE: this will configure the pin for low power
+ *	operation, if several modes of operation are supported these can be
+ *	passed in the argument on a custom form, else just use argument 1
+ *	to indicate low power mode, argument 0 turns low power mode off.
+ * @PIN_CONFIG_OUTPUT: this will configure the pin as an output. Use argument
+ *	1 to indicate high level, argument 0 to indicate low level. (Please
+ *	see Documentation/pinctrl.txt, section "GPIO mode pitfalls" for a
+ *	discussion around this parameter.)
+ * @PIN_CONFIG_END: this is the last enumerator for pin configurations, if
+ *	you need to pass in custom configurations to the pin controller, use
+ *	PIN_CONFIG_END+1 as the base offset.
+ */
+#define PIN_CONFIG_BIAS_DISABLE			0
+#define PIN_CONFIG_BIAS_HIGH_IMPEDANCE		1
+#define PIN_CONFIG_BIAS_BUS_HOLD		2
+#define PIN_CONFIG_BIAS_PULL_UP			3
+#define PIN_CONFIG_BIAS_PULL_DOWN		4
+#define PIN_CONFIG_BIAS_PULL_PIN_DEFAULT	5
+#define PIN_CONFIG_DRIVE_PUSH_PULL		6
+#define PIN_CONFIG_DRIVE_OPEN_DRAIN		7
+#define PIN_CONFIG_DRIVE_OPEN_SOURCE		8
+#define PIN_CONFIG_DRIVE_STRENGTH		9
+#define PIN_CONFIG_INPUT_ENABLE			10
+#define PIN_CONFIG_INPUT_SCHMITT_ENABLE		11
+#define PIN_CONFIG_INPUT_SCHMITT		12
+#define PIN_CONFIG_INPUT_DEBOUNCE		13
+#define PIN_CONFIG_POWER_SOURCE			14
+#define PIN_CONFIG_SLEW_RATE			15
+#define PIN_CONFIG_LOW_POWER_MODE		16
+#define PIN_CONFIG_OUTPUT			17
+#define PIN_CONFIG_END				0x7FFF
+
+#if CONFIG_IS_ENABLED(PINCTRL_GENERIC)
+/**
+ * pinctrl_generic_set_state() - generic set_state operation
+ * Parse the DT node of @config and its children and handle generic properties
+ * such as "pins", "groups", "functions", and pin configuration parameters.
+ *
+ * @pctldev: pinctrl device
+ * @config: config device (pseudo device), pointing a config node in DTS
+ * @return: 0 on success, or negative error code on failure
+ */
+int pinctrl_generic_set_state(struct udevice *pctldev, struct udevice *config);
+#else
+static inline int pinctrl_generic_set_state(struct udevice *pctldev,
+					    struct udevice *config)
+{
+	return -EINVAL;
+}
+#endif
+
+#if CONFIG_IS_ENABLED(PINCTRL)
+/**
+ * pinctrl_select_state() - set a device to a given state
+ *
+ * @dev: peripheral device
+ * @statename: state name, like "default"
+ * @return: 0 on success, or negative error code on failure
+ */
+int pinctrl_select_state(struct udevice *dev, const char *statename);
+#else
+static inline int pinctrl_select_state(struct udevice *dev,
+				       const char *statename)
+{
+	return -EINVAL;
+}
+#endif
+
+#endif /* __PINCTRL_H */

include/dm/uclass-id.h

@@ -44,6 +44,8 @@ enum uclass_id {
 	UCLASS_PCH,		/* x86 platform controller hub */
 	UCLASS_PCI,		/* PCI bus */
 	UCLASS_PCI_GENERIC,	/* Generic PCI bus device */
+	UCLASS_PINCTRL,		/* Pinctrl (pin muxing/configuration) device */
+	UCLASS_PINCONFIG,	/* Pin configuration node device */
 	UCLASS_PMIC,		/* PMIC I/O device */
 	UCLASS_REGULATOR,	/* Regulator device */
 	UCLASS_RESET,		/* Reset device */