Initial import

1 files changed, 671 insertions, 0 deletions

diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
new file mode 100644
index 000000000..b874458dc
--- /dev/null
+++ b/drivers/pinctrl/pinmux.c
@@ -0,0 +1,671 @@
+/*
+ * Core driver for the pin muxing portions of the pin control subsystem
+ *
+ * Copyright (C) 2011-2012 ST-Ericsson SA
+ * Written on behalf of Linaro for ST-Ericsson
+ * Based on bits of regulator core, gpio core and clk core
+ *
+ * Author: Linus Walleij <linus.walleij@linaro.org>
+ *
+ * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ */
+#define pr_fmt(fmt) "pinmux core: " fmt
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/device.h>
+#include <linux/slab.h>
+#include <linux/radix-tree.h>
+#include <linux/err.h>
+#include <linux/list.h>
+#include <linux/string.h>
+#include <linux/sysfs.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/pinctrl/machine.h>
+#include <linux/pinctrl/pinmux.h>
+#include "core.h"
+#include "pinmux.h"
+
+int pinmux_check_ops(struct pinctrl_dev *pctldev)
+{
+	const struct pinmux_ops *ops = pctldev->desc->pmxops;
+	unsigned nfuncs;
+	unsigned selector = 0;
+
+	/* Check that we implement required operations */
+	if (!ops ||
+	    !ops->get_functions_count ||
+	    !ops->get_function_name ||
+	    !ops->get_function_groups ||
+	    !ops->set_mux) {
+		dev_err(pctldev->dev, "pinmux ops lacks necessary functions\n");
+		return -EINVAL;
+	}
+	/* Check that all functions registered have names */
+	nfuncs = ops->get_functions_count(pctldev);
+	while (selector < nfuncs) {
+		const char *fname = ops->get_function_name(pctldev,
+							   selector);
+		if (!fname) {
+			dev_err(pctldev->dev, "pinmux ops has no name for function%u\n",
+				selector);
+			return -EINVAL;
+		}
+		selector++;
+	}
+
+	return 0;
+}
+
+int pinmux_validate_map(struct pinctrl_map const *map, int i)
+{
+	if (!map->data.mux.function) {
+		pr_err("failed to register map %s (%d): no function given\n",
+		       map->name, i);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+/**
+ * pin_request() - request a single pin to be muxed in, typically for GPIO
+ * @pin: the pin number in the global pin space
+ * @owner: a representation of the owner of this pin; typically the device
+ *	name that controls its mux function, or the requested GPIO name
+ * @gpio_range: the range matching the GPIO pin if this is a request for a
+ *	single GPIO pin
+ */
+static int pin_request(struct pinctrl_dev *pctldev,
+		       int pin, const char *owner,
+		       struct pinctrl_gpio_range *gpio_range)
+{
+	struct pin_desc *desc;
+	const struct pinmux_ops *ops = pctldev->desc->pmxops;
+	int status = -EINVAL;
+
+	desc = pin_desc_get(pctldev, pin);
+	if (desc == NULL) {
+		dev_err(pctldev->dev,
+			"pin %d is not registered so it cannot be requested\n",
+			pin);
+		goto out;
+	}
+
+	dev_dbg(pctldev->dev, "request pin %d (%s) for %s\n",
+		pin, desc->name, owner);
+
+	if (gpio_range) {
+		/* There's no need to support multiple GPIO requests */
+		if (desc->gpio_owner) {
+			dev_err(pctldev->dev,
+				"pin %s already requested by %s; cannot claim for %s\n",
+				desc->name, desc->gpio_owner, owner);
+			goto out;
+		}
+
+		desc->gpio_owner = owner;
+	} else {
+		if (desc->mux_usecount && strcmp(desc->mux_owner, owner)) {
+			dev_err(pctldev->dev,
+				"pin %s already requested by %s; cannot claim for %s\n",
+				desc->name, desc->mux_owner, owner);
+			goto out;
+		}
+
+		desc->mux_usecount++;
+		if (desc->mux_usecount > 1)
+			return 0;
+
+		desc->mux_owner = owner;
+	}
+
+	/* Let each pin increase references to this module */
+	if (!try_module_get(pctldev->owner)) {
+		dev_err(pctldev->dev,
+			"could not increase module refcount for pin %d\n",
+			pin);
+		status = -EINVAL;
+		goto out_free_pin;
+	}
+
+	/*
+	 * If there is no kind of request function for the pin we just assume
+	 * we got it by default and proceed.
+	 */
+	if (gpio_range && ops->gpio_request_enable)
+		/* This requests and enables a single GPIO pin */
+		status = ops->gpio_request_enable(pctldev, gpio_range, pin);
+	else if (ops->request)
+		status = ops->request(pctldev, pin);
+	else
+		status = 0;
+
+	if (status) {
+		dev_err(pctldev->dev, "request() failed for pin %d\n", pin);
+		module_put(pctldev->owner);
+	}
+
+out_free_pin:
+	if (status) {
+		if (gpio_range) {
+			desc->gpio_owner = NULL;
+		} else {
+			desc->mux_usecount--;
+			if (!desc->mux_usecount)
+				desc->mux_owner = NULL;
+		}
+	}
+out:
+	if (status)
+		dev_err(pctldev->dev, "pin-%d (%s) status %d\n",
+			pin, owner, status);
+
+	return status;
+}
+
+/**
+ * pin_free() - release a single muxed in pin so something else can be muxed
+ * @pctldev: pin controller device handling this pin
+ * @pin: the pin to free
+ * @gpio_range: the range matching the GPIO pin if this is a request for a
+ *	single GPIO pin
+ *
+ * This function returns a pointer to the previous owner. This is used
+ * for callers that dynamically allocate an owner name so it can be freed
+ * once the pin is free. This is done for GPIO request functions.
+ */
+static const char *pin_free(struct pinctrl_dev *pctldev, int pin,
+			    struct pinctrl_gpio_range *gpio_range)
+{
+	const struct pinmux_ops *ops = pctldev->desc->pmxops;
+	struct pin_desc *desc;
+	const char *owner;
+
+	desc = pin_desc_get(pctldev, pin);
+	if (desc == NULL) {
+		dev_err(pctldev->dev,
+			"pin is not registered so it cannot be freed\n");
+		return NULL;
+	}
+
+	if (!gpio_range) {
+		/*
+		 * A pin should not be freed more times than allocated.
+		 */
+		if (WARN_ON(!desc->mux_usecount))
+			return NULL;
+		desc->mux_usecount--;
+		if (desc->mux_usecount)
+			return NULL;
+	}
+
+	/*
+	 * If there is no kind of request function for the pin we just assume
+	 * we got it by default and proceed.
+	 */
+	if (gpio_range && ops->gpio_disable_free)
+		ops->gpio_disable_free(pctldev, gpio_range, pin);
+	else if (ops->free)
+		ops->free(pctldev, pin);
+
+	if (gpio_range) {
+		owner = desc->gpio_owner;
+		desc->gpio_owner = NULL;
+	} else {
+		owner = desc->mux_owner;
+		desc->mux_owner = NULL;
+		desc->mux_setting = NULL;
+	}
+
+	module_put(pctldev->owner);
+
+	return owner;
+}
+
+/**
+ * pinmux_request_gpio() - request pinmuxing for a GPIO pin
+ * @pctldev: pin controller device affected
+ * @pin: the pin to mux in for GPIO
+ * @range: the applicable GPIO range
+ */
+int pinmux_request_gpio(struct pinctrl_dev *pctldev,
+			struct pinctrl_gpio_range *range,
+			unsigned pin, unsigned gpio)
+{
+	const char *owner;
+	int ret;
+
+	/* Conjure some name stating what chip and pin this is taken by */
+	owner = kasprintf(GFP_KERNEL, "%s:%d", range->name, gpio);
+	if (!owner)
+		return -EINVAL;
+
+	ret = pin_request(pctldev, pin, owner, range);
+	if (ret < 0)
+		kfree(owner);
+
+	return ret;
+}
+
+/**
+ * pinmux_free_gpio() - release a pin from GPIO muxing
+ * @pctldev: the pin controller device for the pin
+ * @pin: the affected currently GPIO-muxed in pin
+ * @range: applicable GPIO range
+ */
+void pinmux_free_gpio(struct pinctrl_dev *pctldev, unsigned pin,
+		      struct pinctrl_gpio_range *range)
+{
+	const char *owner;
+
+	owner = pin_free(pctldev, pin, range);
+	kfree(owner);
+}
+
+/**
+ * pinmux_gpio_direction() - set the direction of a single muxed-in GPIO pin
+ * @pctldev: the pin controller handling this pin
+ * @range: applicable GPIO range
+ * @pin: the affected GPIO pin in this controller
+ * @input: true if we set the pin as input, false for output
+ */
+int pinmux_gpio_direction(struct pinctrl_dev *pctldev,
+			  struct pinctrl_gpio_range *range,
+			  unsigned pin, bool input)
+{
+	const struct pinmux_ops *ops;
+	int ret;
+
+	ops = pctldev->desc->pmxops;
+
+	if (ops->gpio_set_direction)
+		ret = ops->gpio_set_direction(pctldev, range, pin, input);
+	else
+		ret = 0;
+
+	return ret;
+}
+
+static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
+					const char *function)
+{
+	const struct pinmux_ops *ops = pctldev->desc->pmxops;
+	unsigned nfuncs = ops->get_functions_count(pctldev);
+	unsigned selector = 0;
+
+	/* See if this pctldev has this function */
+	while (selector < nfuncs) {
+		const char *fname = ops->get_function_name(pctldev,
+							   selector);
+
+		if (!strcmp(function, fname))
+			return selector;
+
+		selector++;
+	}
+
+	pr_err("%s does not support function %s\n",
+	       pinctrl_dev_get_name(pctldev), function);
+	return -EINVAL;
+}
+
+int pinmux_map_to_setting(struct pinctrl_map const *map,
+			  struct pinctrl_setting *setting)
+{
+	struct pinctrl_dev *pctldev = setting->pctldev;
+	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
+	char const * const *groups;
+	unsigned num_groups;
+	int ret;
+	const char *group;
+	int i;
+
+	if (!pmxops) {
+		dev_err(pctldev->dev, "does not support mux function\n");
+		return -EINVAL;
+	}
+
+	ret = pinmux_func_name_to_selector(pctldev, map->data.mux.function);
+	if (ret < 0) {
+		dev_err(pctldev->dev, "invalid function %s in map table\n",
+			map->data.mux.function);
+		return ret;
+	}
+	setting->data.mux.func = ret;
+
+	ret = pmxops->get_function_groups(pctldev, setting->data.mux.func,
+					  &groups, &num_groups);
+	if (ret < 0) {
+		dev_err(pctldev->dev, "can't query groups for function %s\n",
+			map->data.mux.function);
+		return ret;
+	}
+	if (!num_groups) {
+		dev_err(pctldev->dev,
+			"function %s can't be selected on any group\n",
+			map->data.mux.function);
+		return -EINVAL;
+	}
+	if (map->data.mux.group) {
+		bool found = false;
+		group = map->data.mux.group;
+		for (i = 0; i < num_groups; i++) {
+			if (!strcmp(group, groups[i])) {
+				found = true;
+				break;
+			}
+		}
+		if (!found) {
+			dev_err(pctldev->dev,
+				"invalid group \"%s\" for function \"%s\"\n",
+				group, map->data.mux.function);
+			return -EINVAL;
+		}
+	} else {
+		group = groups[0];
+	}
+
+	ret = pinctrl_get_group_selector(pctldev, group);
+	if (ret < 0) {
+		dev_err(pctldev->dev, "invalid group %s in map table\n",
+			map->data.mux.group);
+		return ret;
+	}
+	setting->data.mux.group = ret;
+
+	return 0;
+}
+
+void pinmux_free_setting(struct pinctrl_setting const *setting)
+{
+	/* This function is currently unused */
+}
+
+int pinmux_enable_setting(struct pinctrl_setting const *setting)
+{
+	struct pinctrl_dev *pctldev = setting->pctldev;
+	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
+	const struct pinmux_ops *ops = pctldev->desc->pmxops;
+	int ret = 0;
+	const unsigned *pins = NULL;
+	unsigned num_pins = 0;
+	int i;
+	struct pin_desc *desc;
+
+	if (pctlops->get_group_pins)
+		ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
+					      &pins, &num_pins);
+
+	if (ret) {
+		const char *gname;
+
+		/* errors only affect debug data, so just warn */
+		gname = pctlops->get_group_name(pctldev,
+						setting->data.mux.group);
+		dev_warn(pctldev->dev,
+			 "could not get pins for group %s\n",
+			 gname);
+		num_pins = 0;
+	}
+
+	/* Try to allocate all pins in this group, one by one */
+	for (i = 0; i < num_pins; i++) {
+		ret = pin_request(pctldev, pins[i], setting->dev_name, NULL);
+		if (ret) {
+			const char *gname;
+			const char *pname;
+
+			desc = pin_desc_get(pctldev, pins[i]);
+			pname = desc ? desc->name : "non-existing";
+			gname = pctlops->get_group_name(pctldev,
+						setting->data.mux.group);
+			dev_err(pctldev->dev,
+				"could not request pin %d (%s) from group %s "
+				" on device %s\n",
+				pins[i], pname, gname,
+				pinctrl_dev_get_name(pctldev));
+			goto err_pin_request;
+		}
+	}
+
+	/* Now that we have acquired the pins, encode the mux setting */
+	for (i = 0; i < num_pins; i++) {
+		desc = pin_desc_get(pctldev, pins[i]);
+		if (desc == NULL) {
+			dev_warn(pctldev->dev,
+				 "could not get pin desc for pin %d\n",
+				 pins[i]);
+			continue;
+		}
+		desc->mux_setting = &(setting->data.mux);
+	}
+
+	ret = ops->set_mux(pctldev, setting->data.mux.func,
+			   setting->data.mux.group);
+
+	if (ret)
+		goto err_set_mux;
+
+	return 0;
+
+err_set_mux:
+	for (i = 0; i < num_pins; i++) {
+		desc = pin_desc_get(pctldev, pins[i]);
+		if (desc)
+			desc->mux_setting = NULL;
+	}
+err_pin_request:
+	/* On error release all taken pins */
+	while (--i >= 0)
+		pin_free(pctldev, pins[i], NULL);
+
+	return ret;
+}
+
+void pinmux_disable_setting(struct pinctrl_setting const *setting)
+{
+	struct pinctrl_dev *pctldev = setting->pctldev;
+	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
+	int ret = 0;
+	const unsigned *pins = NULL;
+	unsigned num_pins = 0;
+	int i;
+	struct pin_desc *desc;
+
+	if (pctlops->get_group_pins)
+		ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
+					      &pins, &num_pins);
+	if (ret) {
+		const char *gname;
+
+		/* errors only affect debug data, so just warn */
+		gname = pctlops->get_group_name(pctldev,
+						setting->data.mux.group);
+		dev_warn(pctldev->dev,
+			 "could not get pins for group %s\n",
+			 gname);
+		num_pins = 0;
+	}
+
+	/* Flag the descs that no setting is active */
+	for (i = 0; i < num_pins; i++) {
+		desc = pin_desc_get(pctldev, pins[i]);
+		if (desc == NULL) {
+			dev_warn(pctldev->dev,
+				 "could not get pin desc for pin %d\n",
+				 pins[i]);
+			continue;
+		}
+		if (desc->mux_setting == &(setting->data.mux)) {
+			desc->mux_setting = NULL;
+			/* And release the pin */
+			pin_free(pctldev, pins[i], NULL);
+		} else {
+			const char *gname;
+
+			gname = pctlops->get_group_name(pctldev,
+						setting->data.mux.group);
+			dev_warn(pctldev->dev,
+				 "not freeing pin %d (%s) as part of "
+				 "deactivating group %s - it is already "
+				 "used for some other setting",
+				 pins[i], desc->name, gname);
+		}
+	}
+}
+
+#ifdef CONFIG_DEBUG_FS
+
+/* Called from pincontrol core */
+static int pinmux_functions_show(struct seq_file *s, void *what)
+{
+	struct pinctrl_dev *pctldev = s->private;
+	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
+	unsigned nfuncs;
+	unsigned func_selector = 0;
+
+	if (!pmxops)
+		return 0;
+
+	mutex_lock(&pctldev->mutex);
+	nfuncs = pmxops->get_functions_count(pctldev);
+	while (func_selector < nfuncs) {
+		const char *func = pmxops->get_function_name(pctldev,
+							  func_selector);
+		const char * const *groups;
+		unsigned num_groups;
+		int ret;
+		int i;
+
+		ret = pmxops->get_function_groups(pctldev, func_selector,
+						  &groups, &num_groups);
+		if (ret)
+			seq_printf(s, "function %s: COULD NOT GET GROUPS\n",
+				   func);
+
+		seq_printf(s, "function: %s, groups = [ ", func);
+		for (i = 0; i < num_groups; i++)
+			seq_printf(s, "%s ", groups[i]);
+		seq_puts(s, "]\n");
+
+		func_selector++;
+	}
+
+	mutex_unlock(&pctldev->mutex);
+
+	return 0;
+}
+
+static int pinmux_pins_show(struct seq_file *s, void *what)
+{
+	struct pinctrl_dev *pctldev = s->private;
+	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
+	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
+	unsigned i, pin;
+
+	if (!pmxops)
+		return 0;
+
+	seq_puts(s, "Pinmux settings per pin\n");
+	seq_puts(s, "Format: pin (name): mux_owner gpio_owner hog?\n");
+
+	mutex_lock(&pctldev->mutex);
+
+	/* The pin number can be retrived from the pin controller descriptor */
+	for (i = 0; i < pctldev->desc->npins; i++) {
+		struct pin_desc *desc;
+		bool is_hog = false;
+
+		pin = pctldev->desc->pins[i].number;
+		desc = pin_desc_get(pctldev, pin);
+		/* Skip if we cannot search the pin */
+		if (desc == NULL)
+			continue;
+
+		if (desc->mux_owner &&
+		    !strcmp(desc->mux_owner, pinctrl_dev_get_name(pctldev)))
+			is_hog = true;
+
+		seq_printf(s, "pin %d (%s): %s %s%s", pin,
+			   desc->name ? desc->name : "unnamed",
+			   desc->mux_owner ? desc->mux_owner
+				: "(MUX UNCLAIMED)",
+			   desc->gpio_owner ? desc->gpio_owner
+				: "(GPIO UNCLAIMED)",
+			   is_hog ? " (HOG)" : "");
+
+		if (desc->mux_setting)
+			seq_printf(s, " function %s group %s\n",
+				   pmxops->get_function_name(pctldev,
+					desc->mux_setting->func),
+				   pctlops->get_group_name(pctldev,
+					desc->mux_setting->group));
+		else
+			seq_printf(s, "\n");
+	}
+
+	mutex_unlock(&pctldev->mutex);
+
+	return 0;
+}
+
+void pinmux_show_map(struct seq_file *s, struct pinctrl_map const *map)
+{
+	seq_printf(s, "group %s\nfunction %s\n",
+		map->data.mux.group ? map->data.mux.group : "(default)",
+		map->data.mux.function);
+}
+
+void pinmux_show_setting(struct seq_file *s,
+			 struct pinctrl_setting const *setting)
+{
+	struct pinctrl_dev *pctldev = setting->pctldev;
+	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
+	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
+
+	seq_printf(s, "group: %s (%u) function: %s (%u)\n",
+		   pctlops->get_group_name(pctldev, setting->data.mux.group),
+		   setting->data.mux.group,
+		   pmxops->get_function_name(pctldev, setting->data.mux.func),
+		   setting->data.mux.func);
+}
+
+static int pinmux_functions_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, pinmux_functions_show, inode->i_private);
+}
+
+static int pinmux_pins_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, pinmux_pins_show, inode->i_private);
+}
+
+static const struct file_operations pinmux_functions_ops = {
+	.open		= pinmux_functions_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+static const struct file_operations pinmux_pins_ops = {
+	.open		= pinmux_pins_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+void pinmux_init_device_debugfs(struct dentry *devroot,
+			 struct pinctrl_dev *pctldev)
+{
+	debugfs_create_file("pinmux-functions", S_IFREG | S_IRUGO,
+			    devroot, pctldev, &pinmux_functions_ops);
+	debugfs_create_file("pinmux-pins", S_IFREG | S_IRUGO,
+			    devroot, pctldev, &pinmux_pins_ops);
+}
+
+#endif /* CONFIG_DEBUG_FS */