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path: root/drivers/pinctrl/pinmux.c
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Diffstat (limited to 'drivers/pinctrl/pinmux.c')
-rw-r--r--drivers/pinctrl/pinmux.c675
1 files changed, 675 insertions, 0 deletions
diff --git a/drivers/pinctrl/pinmux.c b/drivers/pinctrl/pinmux.c
new file mode 100644
index 00000000000..051e8592990
--- /dev/null
+++ b/drivers/pinctrl/pinmux.c
@@ -0,0 +1,675 @@
+/*
+ * 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->enable) {
+ 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->enable(pctldev, setting->data.mux.func,
+ setting->data.mux.group);
+
+ if (ret)
+ goto err_enable;
+
+ return 0;
+
+err_enable:
+ 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;
+ 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;
+ }
+
+ /* 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);
+ }
+ }
+
+ if (ops->disable)
+ ops->disable(pctldev, setting->data.mux.func, setting->data.mux.group);
+}
+
+#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 */
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-04 07:47:34 +0000