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-rw-r--r--drivers/pinctrl/pinmux.c1180
1 files changed, 1180 insertions, 0 deletions
diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
new file mode 100644
index 0000000..6544d98
--- /dev/null
+++ b/drivers/pinctrl/pinmux.c
@@ -0,0 +1,1180 @@
+/*
+ * Core driver for the pin muxing portions of the pin control subsystem
+ *
+ * Copyright (C) 2011 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>
+ *
+ * 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/mutex.h>
+#include <linux/spinlock.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"
+
+/* List of pinmuxes */
+static DEFINE_MUTEX(pinmux_list_mutex);
+static LIST_HEAD(pinmux_list);
+
+/* List of pinmux hogs */
+static DEFINE_MUTEX(pinmux_hoglist_mutex);
+static LIST_HEAD(pinmux_hoglist);
+
+/* Global pinmux maps, we allow one set only */
+static struct pinmux_map const *pinmux_maps;
+static unsigned pinmux_maps_num;
+
+/**
+ * struct pinmux_group - group list item for pinmux groups
+ * @node: pinmux group list node
+ * @group_selector: the group selector for this group
+ */
+struct pinmux_group {
+ struct list_head node;
+ unsigned group_selector;
+};
+
+/**
+ * struct pinmux - per-device pinmux state holder
+ * @node: global list node
+ * @dev: the device using this pinmux
+ * @usecount: the number of active users of this mux setting, used to keep
+ * track of nested use cases
+ * @pins: an array of discrete physical pins used in this mapping, taken
+ * from the global pin enumeration space (copied from pinmux map)
+ * @num_pins: the number of pins in this mapping array, i.e. the number of
+ * elements in .pins so we can iterate over that array (copied from
+ * pinmux map)
+ * @pctldev: pin control device handling this pinmux
+ * @func_selector: the function selector for the pinmux device handling
+ * this pinmux
+ * @groups: the group selectors for the pinmux device and
+ * selector combination handling this pinmux, this is a list that
+ * will be traversed on all pinmux operations such as
+ * get/put/enable/disable
+ * @mutex: a lock for the pinmux state holder
+ */
+struct pinmux {
+ struct list_head node;
+ struct device *dev;
+ unsigned usecount;
+ struct pinctrl_dev *pctldev;
+ unsigned func_selector;
+ struct list_head groups;
+ struct mutex mutex;
+};
+
+/**
+ * struct pinmux_hog - a list item to stash mux hogs
+ * @node: pinmux hog list node
+ * @map: map entry responsible for this hogging
+ * @pmx: the pinmux hogged by this item
+ */
+struct pinmux_hog {
+ struct list_head node;
+ struct pinmux_map const *map;
+ struct pinmux *pmx;
+};
+
+/**
+ * pin_request() - request a single pin to be muxed in, typically for GPIO
+ * @pin: the pin number in the global pin space
+ * @function: a functional name to give to this pin, passed to the driver
+ * so it knows what function to mux in, e.g. the string "gpioNN"
+ * means that you want to mux in the pin for use as GPIO number NN
+ * @gpio: if this request concerns a single GPIO pin
+ * @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 *function, bool gpio,
+ struct pinctrl_gpio_range *gpio_range)
+{
+ struct pin_desc *desc;
+ const struct pinmux_ops *ops = pctldev->desc->pmxops;
+ int status = -EINVAL;
+
+ dev_dbg(&pctldev->dev, "request pin %d for %s\n", pin, function);
+
+ if (!pin_is_valid(pctldev, pin)) {
+ dev_err(&pctldev->dev, "pin is invalid\n");
+ return -EINVAL;
+ }
+
+ if (!function) {
+ dev_err(&pctldev->dev, "no function name given\n");
+ return -EINVAL;
+ }
+
+ desc = pin_desc_get(pctldev, pin);
+ if (desc == NULL) {
+ dev_err(&pctldev->dev,
+ "pin is not registered so it cannot be requested\n");
+ goto out;
+ }
+
+ spin_lock(&desc->lock);
+ if (desc->mux_requested) {
+ spin_unlock(&desc->lock);
+ dev_err(&pctldev->dev,
+ "pin already requested\n");
+ goto out;
+ }
+ desc->mux_requested = true;
+ strncpy(desc->mux_function, function, sizeof(desc->mux_function));
+ spin_unlock(&desc->lock);
+
+ /* 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 && 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 on device %s failed "
+ "for pin %d\n",
+ pctldev->desc->name, pin);
+out_free_pin:
+ if (status) {
+ spin_lock(&desc->lock);
+ desc->mux_requested = false;
+ desc->mux_function[0] = '\0';
+ spin_unlock(&desc->lock);
+ }
+out:
+ if (status)
+ dev_err(&pctldev->dev, "pin-%d (%s) status %d\n",
+ pin, function ? : "?", 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
+ */
+static void pin_free(struct pinctrl_dev *pctldev, int pin)
+{
+ const struct pinmux_ops *ops = pctldev->desc->pmxops;
+ struct pin_desc *desc;
+
+ desc = pin_desc_get(pctldev, pin);
+ if (desc == NULL) {
+ dev_err(&pctldev->dev,
+ "pin is not registered so it cannot be freed\n");
+ return;
+ }
+
+ if (ops->free)
+ ops->free(pctldev, pin);
+
+ spin_lock(&desc->lock);
+ desc->mux_requested = false;
+ desc->mux_function[0] = '\0';
+ spin_unlock(&desc->lock);
+ module_put(pctldev->owner);
+}
+
+/**
+ * pinmux_request_gpio() - request a single pin to be muxed in as GPIO
+ * @gpio: the GPIO pin number from the GPIO subsystem number space
+ */
+int pinmux_request_gpio(unsigned gpio)
+{
+ char gpiostr[16];
+ struct pinctrl_dev *pctldev;
+ struct pinctrl_gpio_range *range;
+ int ret;
+ int pin;
+
+ ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range);
+ if (ret)
+ return -EINVAL;
+
+ /* Convert to the pin controllers number space */
+ pin = gpio - range->base;
+
+ /* Conjure some name stating what chip and pin this is taken by */
+ snprintf(gpiostr, 15, "%s:%d", range->name, gpio);
+
+ return pin_request(pctldev, pin, gpiostr, true, range);
+}
+EXPORT_SYMBOL_GPL(pinmux_request_gpio);
+
+/**
+ * pinmux_free_gpio() - free a single pin, currently used as GPIO
+ * @gpio: the GPIO pin number from the GPIO subsystem number space
+ */
+void pinmux_free_gpio(unsigned gpio)
+{
+ struct pinctrl_dev *pctldev;
+ struct pinctrl_gpio_range *range;
+ int ret;
+ int pin;
+
+ ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range);
+ if (ret)
+ return;
+
+ /* Convert to the pin controllers number space */
+ pin = gpio - range->base;
+
+ pin_free(pctldev, pin);
+}
+EXPORT_SYMBOL_GPL(pinmux_free_gpio);
+
+/**
+ * pinmux_register_mappings() - register a set of pinmux mappings
+ * @maps: the pinmux mappings table to register
+ * @num_maps: the number of maps in the mapping table
+ *
+ * Only call this once during initialization of your machine, the function is
+ * tagged as __init and won't be callable after init has completed. The map
+ * passed into this function will be owned by the pinmux core and cannot be
+ * free:d.
+ */
+int __init pinmux_register_mappings(struct pinmux_map const *maps,
+ unsigned num_maps)
+{
+ int i;
+
+ if (pinmux_maps != NULL) {
+ pr_err("pinmux mappings already registered, you can only "
+ "register one set of maps\n");
+ return -EINVAL;
+ }
+
+ pr_debug("add %d pinmux maps\n", num_maps);
+ for (i = 0; i < num_maps; i++) {
+ /* Sanity check the mapping */
+ if (!maps[i].name) {
+ pr_err("failed to register map %d: "
+ "no map name given\n", i);
+ return -EINVAL;
+ }
+ if (!maps[i].ctrl_dev && !maps[i].ctrl_dev_name) {
+ pr_err("failed to register map %s (%d): "
+ "no pin control device given\n",
+ maps[i].name, i);
+ return -EINVAL;
+ }
+ if (!maps[i].function) {
+ pr_err("failed to register map %s (%d): "
+ "no function ID given\n", maps[i].name, i);
+ return -EINVAL;
+ }
+
+ if (!maps[i].dev && !maps[i].dev_name)
+ pr_debug("add system map %s function %s with no device\n",
+ maps[i].name,
+ maps[i].function);
+ else
+ pr_debug("register map %s, function %s\n",
+ maps[i].name,
+ maps[i].function);
+ }
+
+ pinmux_maps = maps;
+ pinmux_maps_num = num_maps;
+
+ return 0;
+}
+
+/**
+ * acquire_pins() - acquire all the pins for a certain funcion on a pinmux
+ * @pctldev: the device to take the pins on
+ * @func_selector: the function selector to acquire the pins for
+ * @group_selector: the group selector containing the pins to acquire
+ */
+static int acquire_pins(struct pinctrl_dev *pctldev,
+ unsigned func_selector,
+ unsigned group_selector)
+{
+ const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
+ const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
+ const char *func = pmxops->get_function_name(pctldev,
+ func_selector);
+ unsigned *pins;
+ unsigned num_pins;
+ int ret;
+ int i;
+
+ ret = pctlops->get_group_pins(pctldev, group_selector,
+ &pins, &num_pins);
+ if (ret)
+ return ret;
+
+ dev_dbg(&pctldev->dev, "requesting the %u pins from group %u\n",
+ num_pins, group_selector);
+
+ /* Try to allocate all pins in this group, one by one */
+ for (i = 0; i < num_pins; i++) {
+ ret = pin_request(pctldev, pins[i], func, false, NULL);
+ if (ret) {
+ dev_err(&pctldev->dev,
+ "could not get pin %d for function %s "
+ "on device %s - conflicting mux mappings?\n",
+ pins[i], func ? : "(undefined)",
+ pinctrl_dev_get_name(pctldev));
+ /* On error release all taken pins */
+ i--; /* this pin just failed */
+ for (; i >= 0; i--)
+ pin_free(pctldev, pins[i]);
+ return -ENODEV;
+ }
+ }
+ return 0;
+}
+
+/**
+ * release_pins() - release pins taken by earlier acquirement
+ * @pctldev: the device to free the pinx on
+ * @group_selector: the group selector containing the pins to free
+ */
+static void release_pins(struct pinctrl_dev *pctldev,
+ unsigned group_selector)
+{
+ const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
+ unsigned *pins;
+ unsigned num_pins;
+ int ret;
+ int i;
+
+ ret = pctlops->get_group_pins(pctldev, group_selector,
+ &pins, &num_pins);
+ if (ret) {
+ dev_err(&pctldev->dev, "could not get pins to release for "
+ "group selector %d\n",
+ group_selector);
+ return;
+ }
+ for (i = 0; i < num_pins; i++)
+ pin_free(pctldev, pins[i]);
+}
+
+/**
+ * pinmux_get_group_selector() - returns the group selector for a group
+ * @pctldev: the pin controller handling the group
+ * @pin_group: the pin group to look up
+ */
+static int pinmux_get_group_selector(struct pinctrl_dev *pctldev,
+ const char *pin_group)
+{
+ const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
+ unsigned group_selector = 0;
+
+ while (pctlops->list_groups(pctldev, group_selector) >= 0) {
+ const char *gname = pctlops->get_group_name(pctldev,
+ group_selector);
+ if (!strcmp(gname, pin_group)) {
+ dev_dbg(&pctldev->dev,
+ "found group selector %u for %s\n",
+ group_selector,
+ pin_group);
+ return group_selector;
+ }
+
+ group_selector++;
+ }
+
+ dev_err(&pctldev->dev, "does not have pin group %s\n",
+ pin_group);
+
+ return -EINVAL;
+}
+
+/**
+ * pinmux_check_pin_group() - check function and pin group combo
+ * @pctldev: device to check the pin group vs function for
+ * @func_selector: the function selector to check the pin group for, we have
+ * already looked this up in the calling function
+ * @pin_group: the pin group to match to the function
+ *
+ * This function will check that the pinmux driver can supply the
+ * selected pin group for a certain function, returns the group selector if
+ * the group and function selector will work fine together, else returns
+ * negative
+ */
+static int pinmux_check_pin_group(struct pinctrl_dev *pctldev,
+ unsigned func_selector,
+ const char *pin_group)
+{
+ const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
+ const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
+ int ret;
+
+ /*
+ * If the driver does not support different pin groups for the
+ * functions, we only support group 0, and assume this exists.
+ */
+ if (!pctlops || !pctlops->list_groups)
+ return 0;
+
+ /*
+ * Passing NULL (no specific group) will select the first and
+ * hopefully only group of pins available for this function.
+ */
+ if (!pin_group) {
+ char const * const *groups;
+ unsigned num_groups;
+
+ ret = pmxops->get_function_groups(pctldev, func_selector,
+ &groups, &num_groups);
+ if (ret)
+ return ret;
+ if (num_groups < 1)
+ return -EINVAL;
+ ret = pinmux_get_group_selector(pctldev, groups[0]);
+ if (ret < 0) {
+ dev_err(&pctldev->dev,
+ "function %s wants group %s but the pin "
+ "controller does not seem to have that group\n",
+ pmxops->get_function_name(pctldev, func_selector),
+ groups[0]);
+ return ret;
+ }
+
+ if (num_groups > 1)
+ dev_dbg(&pctldev->dev,
+ "function %s support more than one group, "
+ "default-selecting first group %s (%d)\n",
+ pmxops->get_function_name(pctldev, func_selector),
+ groups[0],
+ ret);
+
+ return ret;
+ }
+
+ dev_dbg(&pctldev->dev,
+ "check if we have pin group %s on controller %s\n",
+ pin_group, pinctrl_dev_get_name(pctldev));
+
+ ret = pinmux_get_group_selector(pctldev, pin_group);
+ if (ret < 0) {
+ dev_dbg(&pctldev->dev,
+ "%s does not support pin group %s with function %s\n",
+ pinctrl_dev_get_name(pctldev),
+ pin_group,
+ pmxops->get_function_name(pctldev, func_selector));
+ }
+ return ret;
+}
+
+/**
+ * pinmux_search_function() - check pin control driver for a certain function
+ * @pctldev: device to check for function and position
+ * @map: function map containing the function and position to look for
+ * @func_selector: returns the applicable function selector if found
+ * @group_selector: returns the applicable group selector if found
+ *
+ * This will search the pinmux driver for an applicable
+ * function with a specific pin group, returns 0 if these can be mapped
+ * negative otherwise
+ */
+static int pinmux_search_function(struct pinctrl_dev *pctldev,
+ struct pinmux_map const *map,
+ unsigned *func_selector,
+ unsigned *group_selector)
+{
+ const struct pinmux_ops *ops = pctldev->desc->pmxops;
+ unsigned selector = 0;
+
+ /* See if this pctldev has this function */
+ while (ops->list_functions(pctldev, selector) >= 0) {
+ const char *fname = ops->get_function_name(pctldev,
+ selector);
+ int ret;
+
+ if (!strcmp(map->function, fname)) {
+ /* Found the function, check pin group */
+ ret = pinmux_check_pin_group(pctldev, selector,
+ map->group);
+ if (ret < 0)
+ return ret;
+
+ /* This function and group selector can be used */
+ *func_selector = selector;
+ *group_selector = ret;
+ return 0;
+
+ }
+ selector++;
+ }
+
+ pr_err("%s does not support function %s\n",
+ pinctrl_dev_get_name(pctldev), map->function);
+ return -EINVAL;
+}
+
+/**
+ * pinmux_enable_muxmap() - enable a map entry for a certain pinmux
+ */
+static int pinmux_enable_muxmap(struct pinctrl_dev *pctldev,
+ struct pinmux *pmx,
+ struct device *dev,
+ const char *devname,
+ struct pinmux_map const *map)
+{
+ unsigned func_selector;
+ unsigned group_selector;
+ struct pinmux_group *grp;
+ int ret;
+
+ /*
+ * Note that we're not locking the pinmux mutex here, because
+ * this is only called at pinmux initialization time when it
+ * has not been added to any list and thus is not reachable
+ * by anyone else.
+ */
+
+ if (pmx->pctldev && pmx->pctldev != pctldev) {
+ dev_err(&pctldev->dev,
+ "different pin control devices given for device %s, "
+ "function %s\n",
+ devname,
+ map->function);
+ return -EINVAL;
+ }
+ pmx->dev = dev;
+ pmx->pctldev = pctldev;
+
+ /* Now go into the driver and try to match a function and group */
+ ret = pinmux_search_function(pctldev, map, &func_selector,
+ &group_selector);
+ if (ret < 0)
+ return ret;
+
+ /*
+ * If the function selector is already set, it needs to be identical,
+ * we support several groups with one function but not several
+ * functions with one or several groups in the same pinmux.
+ */
+ if (pmx->func_selector != UINT_MAX &&
+ pmx->func_selector != func_selector) {
+ dev_err(&pctldev->dev,
+ "dual function defines in the map for device %s\n",
+ devname);
+ return -EINVAL;
+ }
+ pmx->func_selector = func_selector;
+
+ /* Now add this group selector, we may have many of them */
+ grp = kmalloc(sizeof(struct pinmux_group), GFP_KERNEL);
+ if (!grp)
+ return -ENOMEM;
+ grp->group_selector = group_selector;
+ ret = acquire_pins(pctldev, func_selector, group_selector);
+ if (ret) {
+ kfree(grp);
+ return ret;
+ }
+ list_add(&grp->node, &pmx->groups);
+
+ return 0;
+}
+
+static void pinmux_free_groups(struct pinmux *pmx)
+{
+ struct list_head *node, *tmp;
+
+ list_for_each_safe(node, tmp, &pmx->groups) {
+ struct pinmux_group *grp =
+ list_entry(node, struct pinmux_group, node);
+ /* Release all pins taken by this group */
+ release_pins(pmx->pctldev, grp->group_selector);
+ list_del(node);
+ kfree(grp);
+ }
+}
+
+/**
+ * pinmux_get() - retrieves the pinmux for a certain device
+ * @dev: the device to get the pinmux for
+ * @name: an optional specific mux mapping name or NULL, the name is only
+ * needed if you want to have more than one mapping per device, or if you
+ * need an anonymous pinmux (not tied to any specific device)
+ */
+struct pinmux *pinmux_get(struct device *dev, const char *name)
+{
+
+ struct pinmux_map const *map = NULL;
+ struct pinctrl_dev *pctldev = NULL;
+ const char *devname = NULL;
+ struct pinmux *pmx;
+ bool found_map;
+ unsigned num_maps = 0;
+ int ret = -ENODEV;
+ int i;
+
+ /* We must have dev or ID or both */
+ if (!dev && !name)
+ return ERR_PTR(-EINVAL);
+
+ if (dev)
+ devname = dev_name(dev);
+
+ pr_debug("get mux %s for device %s\n", name,
+ devname ? devname : "(none)");
+
+ /*
+ * create the state cookie holder struct pinmux for each
+ * mapping, this is what consumers will get when requesting
+ * a pinmux handle with pinmux_get()
+ */
+ pmx = kzalloc(sizeof(struct pinmux), GFP_KERNEL);
+ if (pmx == NULL)
+ return ERR_PTR(-ENOMEM);
+ mutex_init(&pmx->mutex);
+ pmx->func_selector = UINT_MAX;
+ INIT_LIST_HEAD(&pmx->groups);
+
+ /* Iterate over the pinmux maps to locate the right ones */
+ for (i = 0; i < pinmux_maps_num; i++) {
+ map = &pinmux_maps[i];
+ found_map = false;
+
+ /*
+ * First, try to find the pctldev given in the map
+ */
+ pctldev = get_pinctrl_dev_from_dev(map->ctrl_dev,
+ map->ctrl_dev_name);
+ if (!pctldev) {
+ const char *devname = NULL;
+
+ if (map->ctrl_dev)
+ devname = dev_name(map->ctrl_dev);
+ else if (map->ctrl_dev_name)
+ devname = map->ctrl_dev_name;
+
+ pr_warning("could not find a pinctrl device for pinmux "
+ "function %s, fishy, they shall all have one\n",
+ map->function);
+ pr_warning("given pinctrl device name: %s",
+ devname ? devname : "UNDEFINED");
+
+ /* Continue to check the other mappings anyway... */
+ continue;
+ }
+
+ pr_debug("in map, found pctldev %s to handle function %s",
+ dev_name(&pctldev->dev), map->function);
+
+
+ /*
+ * If we're looking for a specific named map, this must match,
+ * else we loop and look for the next.
+ */
+ if (name != NULL) {
+ if (map->name == NULL)
+ continue;
+ if (strcmp(map->name, name))
+ continue;
+ }
+
+ /*
+ * This is for the case where no device name is given, we
+ * already know that the function name matches from above
+ * code.
+ */
+ if (!map->dev_name && (name != NULL))
+ found_map = true;
+
+ /* If the mapping has a device set up it must match */
+ if (map->dev_name &&
+ (!devname || !strcmp(map->dev_name, devname)))
+ /* MATCH! */
+ found_map = true;
+
+ /* If this map is applicable, then apply it */
+ if (found_map) {
+ ret = pinmux_enable_muxmap(pctldev, pmx, dev,
+ devname, map);
+ if (ret) {
+ pinmux_free_groups(pmx);
+ kfree(pmx);
+ return ERR_PTR(ret);
+ }
+ num_maps++;
+ }
+ }
+
+
+ /* We should have atleast one map, right */
+ if (!num_maps) {
+ pr_err("could not find any mux maps for device %s, ID %s\n",
+ devname ? devname : "(anonymous)",
+ name ? name : "(undefined)");
+ kfree(pmx);
+ return ERR_PTR(-EINVAL);
+ }
+
+ pr_debug("found %u mux maps for device %s, UD %s\n",
+ num_maps,
+ devname ? devname : "(anonymous)",
+ name ? name : "(undefined)");
+
+ /* Add the pinmux to the global list */
+ mutex_lock(&pinmux_list_mutex);
+ list_add(&pmx->node, &pinmux_list);
+ mutex_unlock(&pinmux_list_mutex);
+
+ return pmx;
+}
+EXPORT_SYMBOL_GPL(pinmux_get);
+
+/**
+ * pinmux_put() - release a previously claimed pinmux
+ * @pmx: a pinmux previously claimed by pinmux_get()
+ */
+void pinmux_put(struct pinmux *pmx)
+{
+ if (pmx == NULL)
+ return;
+
+ mutex_lock(&pmx->mutex);
+ if (pmx->usecount)
+ pr_warn("releasing pinmux with active users!\n");
+ /* Free the groups and all acquired pins */
+ pinmux_free_groups(pmx);
+ mutex_unlock(&pmx->mutex);
+
+ /* Remove from list */
+ mutex_lock(&pinmux_list_mutex);
+ list_del(&pmx->node);
+ mutex_unlock(&pinmux_list_mutex);
+
+ kfree(pmx);
+}
+EXPORT_SYMBOL_GPL(pinmux_put);
+
+/**
+ * pinmux_enable() - enable a certain pinmux setting
+ * @pmx: the pinmux to enable, previously claimed by pinmux_get()
+ */
+int pinmux_enable(struct pinmux *pmx)
+{
+ int ret = 0;
+
+ if (pmx == NULL)
+ return -EINVAL;
+ mutex_lock(&pmx->mutex);
+ if (pmx->usecount++ == 0) {
+ struct pinctrl_dev *pctldev = pmx->pctldev;
+ const struct pinmux_ops *ops = pctldev->desc->pmxops;
+ struct pinmux_group *grp;
+
+ list_for_each_entry(grp, &pmx->groups, node) {
+ ret = ops->enable(pctldev, pmx->func_selector,
+ grp->group_selector);
+ if (ret) {
+ /*
+ * TODO: call disable() on all groups we called
+ * enable() on to this point?
+ */
+ pmx->usecount--;
+ break;
+ }
+ }
+ }
+ mutex_unlock(&pmx->mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(pinmux_enable);
+
+/**
+ * pinmux_disable() - disable a certain pinmux setting
+ * @pmx: the pinmux to disable, previously claimed by pinmux_get()
+ */
+void pinmux_disable(struct pinmux *pmx)
+{
+ if (pmx == NULL)
+ return;
+
+ mutex_lock(&pmx->mutex);
+ if (--pmx->usecount == 0) {
+ struct pinctrl_dev *pctldev = pmx->pctldev;
+ const struct pinmux_ops *ops = pctldev->desc->pmxops;
+ struct pinmux_group *grp;
+
+ list_for_each_entry(grp, &pmx->groups, node) {
+ ops->disable(pctldev, pmx->func_selector,
+ grp->group_selector);
+ }
+ }
+ mutex_unlock(&pmx->mutex);
+}
+EXPORT_SYMBOL_GPL(pinmux_disable);
+
+int pinmux_check_ops(const struct pinmux_ops *ops)
+{
+ /* Check that we implement required operations */
+ if (!ops->list_functions ||
+ !ops->get_function_name ||
+ !ops->get_function_groups ||
+ !ops->enable ||
+ !ops->disable)
+ return -EINVAL;
+
+ return 0;
+}
+
+/* Hog a single map entry and add to the hoglist */
+static int pinmux_hog_map(struct pinctrl_dev *pctldev,
+ struct pinmux_map const *map)
+{
+ struct pinmux_hog *hog;
+ struct pinmux *pmx;
+ int ret;
+
+ if (map->dev || map->dev_name) {
+ /*
+ * TODO: the day we have device tree support, we can
+ * traverse the device tree and hog to specific device nodes
+ * without any problems, so then we can hog pinmuxes for
+ * all devices that just want a static pin mux at this point.
+ */
+ dev_err(&pctldev->dev, "map %s wants to hog a non-system "
+ "pinmux, this is not going to work\n", map->name);
+ return -EINVAL;
+ }
+
+ hog = kzalloc(sizeof(struct pinmux_hog), GFP_KERNEL);
+ if (!hog)
+ return -ENOMEM;
+
+ pmx = pinmux_get(NULL, map->name);
+ if (IS_ERR(pmx)) {
+ kfree(hog);
+ dev_err(&pctldev->dev,
+ "could not get the %s pinmux mapping for hogging\n",
+ map->name);
+ return PTR_ERR(pmx);
+ }
+
+ ret = pinmux_enable(pmx);
+ if (ret) {
+ pinmux_put(pmx);
+ kfree(hog);
+ dev_err(&pctldev->dev,
+ "could not enable the %s pinmux mapping for hogging\n",
+ map->name);
+ return ret;
+ }
+
+ hog->map = map;
+ hog->pmx = pmx;
+
+ dev_info(&pctldev->dev, "hogged map %s, function %s\n", map->name,
+ map->function);
+ mutex_lock(&pctldev->pinmux_hogs_lock);
+ list_add(&hog->node, &pctldev->pinmux_hogs);
+ mutex_unlock(&pctldev->pinmux_hogs_lock);
+
+ return 0;
+}
+
+/**
+ * pinmux_hog_maps() - hog specific map entries on controller device
+ * @pctldev: the pin control device to hog entries on
+ *
+ * When the pin controllers are registered, there may be some specific pinmux
+ * map entries that need to be hogged, i.e. get+enabled until the system shuts
+ * down.
+ */
+int pinmux_hog_maps(struct pinctrl_dev *pctldev)
+{
+ struct device *dev = &pctldev->dev;
+ const char *devname = dev_name(dev);
+ int ret;
+ int i;
+
+ INIT_LIST_HEAD(&pctldev->pinmux_hogs);
+ mutex_init(&pctldev->pinmux_hogs_lock);
+
+ for (i = 0; i < pinmux_maps_num; i++) {
+ struct pinmux_map const *map = &pinmux_maps[i];
+
+ if (((map->ctrl_dev == dev) ||
+ !strcmp(map->ctrl_dev_name, devname)) &&
+ map->hog_on_boot) {
+ /* OK time to hog! */
+ ret = pinmux_hog_map(pctldev, map);
+ if (ret)
+ return ret;
+ }
+ }
+ return 0;
+}
+
+/**
+ * pinmux_hog_maps() - unhog specific map entries on controller device
+ * @pctldev: the pin control device to unhog entries on
+ */
+void pinmux_unhog_maps(struct pinctrl_dev *pctldev)
+{
+ struct list_head *node, *tmp;
+
+ mutex_lock(&pctldev->pinmux_hogs_lock);
+ list_for_each_safe(node, tmp, &pctldev->pinmux_hogs) {
+ struct pinmux_hog *hog =
+ list_entry(node, struct pinmux_hog, node);
+ pinmux_disable(hog->pmx);
+ pinmux_put(hog->pmx);
+ list_del(node);
+ kfree(hog);
+ }
+ mutex_unlock(&pctldev->pinmux_hogs_lock);
+}
+
+#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 func_selector = 0;
+
+ while (pmxops->list_functions(pctldev, func_selector) >= 0) {
+ 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++;
+
+ }
+
+ return 0;
+}
+
+static int pinmux_pins_show(struct seq_file *s, void *what)
+{
+ struct pinctrl_dev *pctldev = s->private;
+ unsigned pin;
+
+ seq_puts(s, "Pinmux settings per pin\n");
+ seq_puts(s, "Format: pin (name): pinmuxfunction\n");
+
+ /* The highest pin number need to be included in the loop, thus <= */
+ for (pin = 0; pin <= pctldev->desc->maxpin; pin++) {
+
+ struct pin_desc *desc;
+
+ desc = pin_desc_get(pctldev, pin);
+ /* Pin space may be sparse */
+ if (desc == NULL)
+ continue;
+
+ seq_printf(s, "pin %d (%s): %s\n", pin,
+ desc->name ? desc->name : "unnamed",
+ desc->mux_requested ? desc->mux_function : "UNCLAIMED");
+ }
+
+ return 0;
+}
+
+static int pinmux_hogs_show(struct seq_file *s, void *what)
+{
+ struct pinctrl_dev *pctldev = s->private;
+ struct pinmux_hog *hog;
+
+ seq_puts(s, "Pinmux map hogs held by device\n");
+
+ list_for_each_entry(hog, &pctldev->pinmux_hogs, node)
+ seq_printf(s, "%s\n", hog->map->name);
+
+ return 0;
+}
+
+static int pinmux_show(struct seq_file *s, void *what)
+{
+ struct pinmux *pmx;
+
+ seq_puts(s, "Requested pinmuxes and their maps:\n");
+ list_for_each_entry(pmx, &pinmux_list, node) {
+ struct pinctrl_dev *pctldev = pmx->pctldev;
+ const struct pinmux_ops *pmxops;
+ const struct pinctrl_ops *pctlops;
+ struct pinmux_group *grp;
+
+ if (!pctldev) {
+ seq_puts(s, "NO PIN CONTROLLER DEVICE\n");
+ continue;
+ }
+
+ pmxops = pctldev->desc->pmxops;
+ pctlops = pctldev->desc->pctlops;
+
+ seq_printf(s, "device: %s function: %s (%u),",
+ pinctrl_dev_get_name(pmx->pctldev),
+ pmxops->get_function_name(pctldev, pmx->func_selector),
+ pmx->func_selector);
+
+ seq_printf(s, " groups: [");
+ list_for_each_entry(grp, &pmx->groups, node) {
+ seq_printf(s, " %s (%u)",
+ pctlops->get_group_name(pctldev, grp->group_selector),
+ grp->group_selector);
+ }
+ seq_printf(s, " ]");
+
+ seq_printf(s, " users: %u map-> %s\n",
+ pmx->usecount,
+ pmx->dev ? dev_name(pmx->dev) : "(system)");
+ }
+
+ return 0;
+}
+
+static int pinmux_maps_show(struct seq_file *s, void *what)
+{
+ int i;
+
+ seq_puts(s, "Pinmux maps:\n");
+
+ for (i = 0; i < pinmux_maps_num; i++) {
+ struct pinmux_map const *map = &pinmux_maps[i];
+
+ seq_printf(s, "%s:\n", map->name);
+ if (map->dev || map->dev_name)
+ seq_printf(s, " device: %s\n",
+ map->dev ? dev_name(map->dev) :
+ map->dev_name);
+ else
+ seq_printf(s, " SYSTEM MUX\n");
+ seq_printf(s, " controlling device %s\n",
+ map->ctrl_dev ? dev_name(map->ctrl_dev) :
+ map->ctrl_dev_name);
+ seq_printf(s, " function: %s\n", map->function);
+ seq_printf(s, " group: %s\n", map->group ? map->group :
+ "(default)");
+ }
+ return 0;
+}
+
+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 int pinmux_hogs_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, pinmux_hogs_show, inode->i_private);
+}
+
+static int pinmux_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, pinmux_show, NULL);
+}
+
+static int pinmux_maps_open(struct inode *inode, struct file *file)
+{
+ return single_open(file, pinmux_maps_show, NULL);
+}
+
+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,
+};
+
+static const struct file_operations pinmux_hogs_ops = {
+ .open = pinmux_hogs_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static const struct file_operations pinmux_ops = {
+ .open = pinmux_open,
+ .read = seq_read,
+ .llseek = seq_lseek,
+ .release = single_release,
+};
+
+static const struct file_operations pinmux_maps_ops = {
+ .open = pinmux_maps_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);
+ debugfs_create_file("pinmux-hogs", S_IFREG | S_IRUGO,
+ devroot, pctldev, &pinmux_hogs_ops);
+}
+
+void pinmux_init_debugfs(struct dentry *subsys_root)
+{
+ debugfs_create_file("pinmuxes", S_IFREG | S_IRUGO,
+ subsys_root, NULL, &pinmux_ops);
+ debugfs_create_file("pinmux-maps", S_IFREG | S_IRUGO,
+ subsys_root, NULL, &pinmux_maps_ops);
+}
+
+#endif /* CONFIG_DEBUG_FS */
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