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-rw-r--r--arch/arm/plat-omap/omap_device.c867
1 files changed, 867 insertions, 0 deletions
diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
new file mode 100644
index 00000000..49fc0df0
--- /dev/null
+++ b/arch/arm/plat-omap/omap_device.c
@@ -0,0 +1,867 @@
+/*
+ * omap_device implementation
+ *
+ * Copyright (C) 2009-2010 Nokia Corporation
+ * Paul Walmsley, Kevin Hilman
+ *
+ * Developed in collaboration with (alphabetical order): Benoit
+ * Cousson, Thara Gopinath, Tony Lindgren, Rajendra Nayak, Vikram
+ * Pandita, Sakari Poussa, Anand Sawant, Santosh Shilimkar, Richard
+ * Woodruff
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This code provides a consistent interface for OMAP device drivers
+ * to control power management and interconnect properties of their
+ * devices.
+ *
+ * In the medium- to long-term, this code should either be
+ * a) implemented via arch-specific pointers in platform_data
+ * or
+ * b) implemented as a proper omap_bus/omap_device in Linux, no more
+ * platform_data func pointers
+ *
+ *
+ * Guidelines for usage by driver authors:
+ *
+ * 1. These functions are intended to be used by device drivers via
+ * function pointers in struct platform_data. As an example,
+ * omap_device_enable() should be passed to the driver as
+ *
+ * struct foo_driver_platform_data {
+ * ...
+ * int (*device_enable)(struct platform_device *pdev);
+ * ...
+ * }
+ *
+ * Note that the generic "device_enable" name is used, rather than
+ * "omap_device_enable". This is so other architectures can pass in their
+ * own enable/disable functions here.
+ *
+ * This should be populated during device setup:
+ *
+ * ...
+ * pdata->device_enable = omap_device_enable;
+ * ...
+ *
+ * 2. Drivers should first check to ensure the function pointer is not null
+ * before calling it, as in:
+ *
+ * if (pdata->device_enable)
+ * pdata->device_enable(pdev);
+ *
+ * This allows other architectures that don't use similar device_enable()/
+ * device_shutdown() functions to execute normally.
+ *
+ * ...
+ *
+ * Suggested usage by device drivers:
+ *
+ * During device initialization:
+ * device_enable()
+ *
+ * During device idle:
+ * (save remaining device context if necessary)
+ * device_idle();
+ *
+ * During device resume:
+ * device_enable();
+ * (restore context if necessary)
+ *
+ * During device shutdown:
+ * device_shutdown()
+ * (device must be reinitialized at this point to use it again)
+ *
+ */
+#undef DEBUG
+
+#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/pm_runtime.h>
+
+#include <plat/omap_device.h>
+#include <plat/omap_hwmod.h>
+#include <plat/clock.h>
+
+/* These parameters are passed to _omap_device_{de,}activate() */
+#define USE_WAKEUP_LAT 0
+#define IGNORE_WAKEUP_LAT 1
+
+/* Private functions */
+
+/**
+ * _omap_device_activate - increase device readiness
+ * @od: struct omap_device *
+ * @ignore_lat: increase to latency target (0) or full readiness (1)?
+ *
+ * Increase readiness of omap_device @od (thus decreasing device
+ * wakeup latency, but consuming more power). If @ignore_lat is
+ * IGNORE_WAKEUP_LAT, make the omap_device fully active. Otherwise,
+ * if @ignore_lat is USE_WAKEUP_LAT, and the device's maximum wakeup
+ * latency is greater than the requested maximum wakeup latency, step
+ * backwards in the omap_device_pm_latency table to ensure the
+ * device's maximum wakeup latency is less than or equal to the
+ * requested maximum wakeup latency. Returns 0.
+ */
+static int _omap_device_activate(struct omap_device *od, u8 ignore_lat)
+{
+ struct timespec a, b, c;
+
+ pr_debug("omap_device: %s: activating\n", od->pdev.name);
+
+ while (od->pm_lat_level > 0) {
+ struct omap_device_pm_latency *odpl;
+ unsigned long long act_lat = 0;
+
+ od->pm_lat_level--;
+
+ odpl = od->pm_lats + od->pm_lat_level;
+
+ if (!ignore_lat &&
+ (od->dev_wakeup_lat <= od->_dev_wakeup_lat_limit))
+ break;
+
+ read_persistent_clock(&a);
+
+ /* XXX check return code */
+ odpl->activate_func(od);
+
+ read_persistent_clock(&b);
+
+ c = timespec_sub(b, a);
+ act_lat = timespec_to_ns(&c);
+
+ pr_debug("omap_device: %s: pm_lat %d: activate: elapsed time "
+ "%llu nsec\n", od->pdev.name, od->pm_lat_level,
+ act_lat);
+
+ if (act_lat > odpl->activate_lat) {
+ odpl->activate_lat_worst = act_lat;
+ if (odpl->flags & OMAP_DEVICE_LATENCY_AUTO_ADJUST) {
+ odpl->activate_lat = act_lat;
+ pr_warning("omap_device: %s.%d: new worst case "
+ "activate latency %d: %llu\n",
+ od->pdev.name, od->pdev.id,
+ od->pm_lat_level, act_lat);
+ } else
+ pr_warning("omap_device: %s.%d: activate "
+ "latency %d higher than exptected. "
+ "(%llu > %d)\n",
+ od->pdev.name, od->pdev.id,
+ od->pm_lat_level, act_lat,
+ odpl->activate_lat);
+ }
+
+ od->dev_wakeup_lat -= odpl->activate_lat;
+ }
+
+ return 0;
+}
+
+/**
+ * _omap_device_deactivate - decrease device readiness
+ * @od: struct omap_device *
+ * @ignore_lat: decrease to latency target (0) or full inactivity (1)?
+ *
+ * Decrease readiness of omap_device @od (thus increasing device
+ * wakeup latency, but conserving power). If @ignore_lat is
+ * IGNORE_WAKEUP_LAT, make the omap_device fully inactive. Otherwise,
+ * if @ignore_lat is USE_WAKEUP_LAT, and the device's maximum wakeup
+ * latency is less than the requested maximum wakeup latency, step
+ * forwards in the omap_device_pm_latency table to ensure the device's
+ * maximum wakeup latency is less than or equal to the requested
+ * maximum wakeup latency. Returns 0.
+ */
+static int _omap_device_deactivate(struct omap_device *od, u8 ignore_lat)
+{
+ struct timespec a, b, c;
+
+ pr_debug("omap_device: %s: deactivating\n", od->pdev.name);
+
+ while (od->pm_lat_level < od->pm_lats_cnt) {
+ struct omap_device_pm_latency *odpl;
+ unsigned long long deact_lat = 0;
+
+ odpl = od->pm_lats + od->pm_lat_level;
+
+ if (!ignore_lat &&
+ ((od->dev_wakeup_lat + odpl->activate_lat) >
+ od->_dev_wakeup_lat_limit))
+ break;
+
+ read_persistent_clock(&a);
+
+ /* XXX check return code */
+ odpl->deactivate_func(od);
+
+ read_persistent_clock(&b);
+
+ c = timespec_sub(b, a);
+ deact_lat = timespec_to_ns(&c);
+
+ pr_debug("omap_device: %s: pm_lat %d: deactivate: elapsed time "
+ "%llu nsec\n", od->pdev.name, od->pm_lat_level,
+ deact_lat);
+
+ if (deact_lat > odpl->deactivate_lat) {
+ odpl->deactivate_lat_worst = deact_lat;
+ if (odpl->flags & OMAP_DEVICE_LATENCY_AUTO_ADJUST) {
+ odpl->deactivate_lat = deact_lat;
+ pr_warning("omap_device: %s.%d: new worst case "
+ "deactivate latency %d: %llu\n",
+ od->pdev.name, od->pdev.id,
+ od->pm_lat_level, deact_lat);
+ } else
+ pr_warning("omap_device: %s.%d: deactivate "
+ "latency %d higher than exptected. "
+ "(%llu > %d)\n",
+ od->pdev.name, od->pdev.id,
+ od->pm_lat_level, deact_lat,
+ odpl->deactivate_lat);
+ }
+
+
+ od->dev_wakeup_lat += odpl->activate_lat;
+
+ od->pm_lat_level++;
+ }
+
+ return 0;
+}
+
+static inline struct omap_device *_find_by_pdev(struct platform_device *pdev)
+{
+ return container_of(pdev, struct omap_device, pdev);
+}
+
+/**
+ * _add_optional_clock_clkdev - Add clkdev entry for hwmod optional clocks
+ * @od: struct omap_device *od
+ *
+ * For every optional clock present per hwmod per omap_device, this function
+ * adds an entry in the clkdev table of the form <dev-id=dev_name, con-id=role>
+ * if it does not exist already.
+ *
+ * The function is called from inside omap_device_build_ss(), after
+ * omap_device_register.
+ *
+ * This allows drivers to get a pointer to its optional clocks based on its role
+ * by calling clk_get(<dev*>, <role>).
+ *
+ * No return value.
+ */
+static void _add_optional_clock_clkdev(struct omap_device *od,
+ struct omap_hwmod *oh)
+{
+ int i;
+
+ for (i = 0; i < oh->opt_clks_cnt; i++) {
+ struct omap_hwmod_opt_clk *oc;
+ struct clk *r;
+ struct clk_lookup *l;
+
+ oc = &oh->opt_clks[i];
+
+ if (!oc->_clk)
+ continue;
+
+ r = clk_get_sys(dev_name(&od->pdev.dev), oc->role);
+ if (!IS_ERR(r))
+ continue; /* clkdev entry exists */
+
+ r = omap_clk_get_by_name((char *)oc->clk);
+ if (IS_ERR(r)) {
+ pr_err("omap_device: %s: omap_clk_get_by_name for %s failed\n",
+ dev_name(&od->pdev.dev), oc->clk);
+ continue;
+ }
+
+ l = clkdev_alloc(r, oc->role, dev_name(&od->pdev.dev));
+ if (!l) {
+ pr_err("omap_device: %s: clkdev_alloc for %s failed\n",
+ dev_name(&od->pdev.dev), oc->role);
+ return;
+ }
+ clkdev_add(l);
+ }
+}
+
+
+/* Public functions for use by core code */
+
+/**
+ * omap_device_get_context_loss_count - get lost context count
+ * @od: struct omap_device *
+ *
+ * Using the primary hwmod, query the context loss count for this
+ * device.
+ *
+ * Callers should consider context for this device lost any time this
+ * function returns a value different than the value the caller got
+ * the last time it called this function.
+ *
+ * If any hwmods exist for the omap_device assoiated with @pdev,
+ * return the context loss counter for that hwmod, otherwise return
+ * zero.
+ */
+u32 omap_device_get_context_loss_count(struct platform_device *pdev)
+{
+ struct omap_device *od;
+ u32 ret = 0;
+
+ od = _find_by_pdev(pdev);
+
+ if (od->hwmods_cnt)
+ ret = omap_hwmod_get_context_loss_count(od->hwmods[0]);
+
+ return ret;
+}
+
+/**
+ * omap_device_count_resources - count number of struct resource entries needed
+ * @od: struct omap_device *
+ *
+ * Count the number of struct resource entries needed for this
+ * omap_device @od. Used by omap_device_build_ss() to determine how
+ * much memory to allocate before calling
+ * omap_device_fill_resources(). Returns the count.
+ */
+int omap_device_count_resources(struct omap_device *od)
+{
+ int c = 0;
+ int i;
+
+ for (i = 0; i < od->hwmods_cnt; i++)
+ c += omap_hwmod_count_resources(od->hwmods[i]);
+
+ pr_debug("omap_device: %s: counted %d total resources across %d "
+ "hwmods\n", od->pdev.name, c, od->hwmods_cnt);
+
+ return c;
+}
+
+/**
+ * omap_device_fill_resources - fill in array of struct resource
+ * @od: struct omap_device *
+ * @res: pointer to an array of struct resource to be filled in
+ *
+ * Populate one or more empty struct resource pointed to by @res with
+ * the resource data for this omap_device @od. Used by
+ * omap_device_build_ss() after calling omap_device_count_resources().
+ * Ideally this function would not be needed at all. If omap_device
+ * replaces platform_device, then we can specify our own
+ * get_resource()/ get_irq()/etc functions that use the underlying
+ * omap_hwmod information. Or if platform_device is extended to use
+ * subarchitecture-specific function pointers, the various
+ * platform_device functions can simply call omap_device internal
+ * functions to get device resources. Hacking around the existing
+ * platform_device code wastes memory. Returns 0.
+ */
+int omap_device_fill_resources(struct omap_device *od, struct resource *res)
+{
+ int c = 0;
+ int i, r;
+
+ for (i = 0; i < od->hwmods_cnt; i++) {
+ r = omap_hwmod_fill_resources(od->hwmods[i], res);
+ res += r;
+ c += r;
+ }
+
+ return 0;
+}
+
+/**
+ * omap_device_build - build and register an omap_device with one omap_hwmod
+ * @pdev_name: name of the platform_device driver to use
+ * @pdev_id: this platform_device's connection ID
+ * @oh: ptr to the single omap_hwmod that backs this omap_device
+ * @pdata: platform_data ptr to associate with the platform_device
+ * @pdata_len: amount of memory pointed to by @pdata
+ * @pm_lats: pointer to a omap_device_pm_latency array for this device
+ * @pm_lats_cnt: ARRAY_SIZE() of @pm_lats
+ * @is_early_device: should the device be registered as an early device or not
+ *
+ * Convenience function for building and registering a single
+ * omap_device record, which in turn builds and registers a
+ * platform_device record. See omap_device_build_ss() for more
+ * information. Returns ERR_PTR(-EINVAL) if @oh is NULL; otherwise,
+ * passes along the return value of omap_device_build_ss().
+ */
+struct omap_device *omap_device_build(const char *pdev_name, int pdev_id,
+ struct omap_hwmod *oh, void *pdata,
+ int pdata_len,
+ struct omap_device_pm_latency *pm_lats,
+ int pm_lats_cnt, int is_early_device)
+{
+ struct omap_hwmod *ohs[] = { oh };
+
+ if (!oh)
+ return ERR_PTR(-EINVAL);
+
+ return omap_device_build_ss(pdev_name, pdev_id, ohs, 1, pdata,
+ pdata_len, pm_lats, pm_lats_cnt,
+ is_early_device);
+}
+
+/**
+ * omap_device_build_ss - build and register an omap_device with multiple hwmods
+ * @pdev_name: name of the platform_device driver to use
+ * @pdev_id: this platform_device's connection ID
+ * @oh: ptr to the single omap_hwmod that backs this omap_device
+ * @pdata: platform_data ptr to associate with the platform_device
+ * @pdata_len: amount of memory pointed to by @pdata
+ * @pm_lats: pointer to a omap_device_pm_latency array for this device
+ * @pm_lats_cnt: ARRAY_SIZE() of @pm_lats
+ * @is_early_device: should the device be registered as an early device or not
+ *
+ * Convenience function for building and registering an omap_device
+ * subsystem record. Subsystem records consist of multiple
+ * omap_hwmods. This function in turn builds and registers a
+ * platform_device record. Returns an ERR_PTR() on error, or passes
+ * along the return value of omap_device_register().
+ */
+struct omap_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
+ struct omap_hwmod **ohs, int oh_cnt,
+ void *pdata, int pdata_len,
+ struct omap_device_pm_latency *pm_lats,
+ int pm_lats_cnt, int is_early_device)
+{
+ int ret = -ENOMEM;
+ struct omap_device *od;
+ char *pdev_name2;
+ struct resource *res = NULL;
+ int i, res_count;
+ struct omap_hwmod **hwmods;
+
+ if (!ohs || oh_cnt == 0 || !pdev_name)
+ return ERR_PTR(-EINVAL);
+
+ if (!pdata && pdata_len > 0)
+ return ERR_PTR(-EINVAL);
+
+ pr_debug("omap_device: %s: building with %d hwmods\n", pdev_name,
+ oh_cnt);
+
+ od = kzalloc(sizeof(struct omap_device), GFP_KERNEL);
+ if (!od)
+ return ERR_PTR(-ENOMEM);
+
+ od->hwmods_cnt = oh_cnt;
+
+ hwmods = kzalloc(sizeof(struct omap_hwmod *) * oh_cnt,
+ GFP_KERNEL);
+ if (!hwmods)
+ goto odbs_exit1;
+
+ memcpy(hwmods, ohs, sizeof(struct omap_hwmod *) * oh_cnt);
+ od->hwmods = hwmods;
+
+ pdev_name2 = kzalloc(strlen(pdev_name) + 1, GFP_KERNEL);
+ if (!pdev_name2)
+ goto odbs_exit2;
+ strcpy(pdev_name2, pdev_name);
+
+ od->pdev.name = pdev_name2;
+ od->pdev.id = pdev_id;
+
+ res_count = omap_device_count_resources(od);
+ if (res_count > 0) {
+ res = kzalloc(sizeof(struct resource) * res_count, GFP_KERNEL);
+ if (!res)
+ goto odbs_exit3;
+ }
+ omap_device_fill_resources(od, res);
+
+ od->pdev.num_resources = res_count;
+ od->pdev.resource = res;
+
+ ret = platform_device_add_data(&od->pdev, pdata, pdata_len);
+ if (ret)
+ goto odbs_exit4;
+
+ od->pm_lats = pm_lats;
+ od->pm_lats_cnt = pm_lats_cnt;
+
+ if (is_early_device)
+ ret = omap_early_device_register(od);
+ else
+ ret = omap_device_register(od);
+
+ for (i = 0; i < oh_cnt; i++) {
+ hwmods[i]->od = od;
+ _add_optional_clock_clkdev(od, hwmods[i]);
+ }
+
+ if (ret)
+ goto odbs_exit4;
+
+ return od;
+
+odbs_exit4:
+ kfree(res);
+odbs_exit3:
+ kfree(pdev_name2);
+odbs_exit2:
+ kfree(hwmods);
+odbs_exit1:
+ kfree(od);
+
+ pr_err("omap_device: %s: build failed (%d)\n", pdev_name, ret);
+
+ return ERR_PTR(ret);
+}
+
+/**
+ * omap_early_device_register - register an omap_device as an early platform
+ * device.
+ * @od: struct omap_device * to register
+ *
+ * Register the omap_device structure. This currently just calls
+ * platform_early_add_device() on the underlying platform_device.
+ * Returns 0 by default.
+ */
+int omap_early_device_register(struct omap_device *od)
+{
+ struct platform_device *devices[1];
+
+ devices[0] = &(od->pdev);
+ early_platform_add_devices(devices, 1);
+ return 0;
+}
+
+static int _od_runtime_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ int ret;
+
+ ret = pm_generic_runtime_suspend(dev);
+
+ if (!ret)
+ omap_device_idle(pdev);
+
+ return ret;
+}
+
+static int _od_runtime_idle(struct device *dev)
+{
+ return pm_generic_runtime_idle(dev);
+}
+
+static int _od_runtime_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+
+ omap_device_enable(pdev);
+
+ return pm_generic_runtime_resume(dev);
+}
+
+static struct dev_power_domain omap_device_power_domain = {
+ .ops = {
+ .runtime_suspend = _od_runtime_suspend,
+ .runtime_idle = _od_runtime_idle,
+ .runtime_resume = _od_runtime_resume,
+ USE_PLATFORM_PM_SLEEP_OPS
+ }
+};
+
+/**
+ * omap_device_register - register an omap_device with one omap_hwmod
+ * @od: struct omap_device * to register
+ *
+ * Register the omap_device structure. This currently just calls
+ * platform_device_register() on the underlying platform_device.
+ * Returns the return value of platform_device_register().
+ */
+int omap_device_register(struct omap_device *od)
+{
+ pr_debug("omap_device: %s: registering\n", od->pdev.name);
+
+ od->pdev.dev.parent = &omap_device_parent;
+ od->pdev.dev.pwr_domain = &omap_device_power_domain;
+ return platform_device_register(&od->pdev);
+}
+
+
+/* Public functions for use by device drivers through struct platform_data */
+
+/**
+ * omap_device_enable - fully activate an omap_device
+ * @od: struct omap_device * to activate
+ *
+ * Do whatever is necessary for the hwmods underlying omap_device @od
+ * to be accessible and ready to operate. This generally involves
+ * enabling clocks, setting SYSCONFIG registers; and in the future may
+ * involve remuxing pins. Device drivers should call this function
+ * (through platform_data function pointers) where they would normally
+ * enable clocks, etc. Returns -EINVAL if called when the omap_device
+ * is already enabled, or passes along the return value of
+ * _omap_device_activate().
+ */
+int omap_device_enable(struct platform_device *pdev)
+{
+ int ret;
+ struct omap_device *od;
+
+ od = _find_by_pdev(pdev);
+
+ if (od->_state == OMAP_DEVICE_STATE_ENABLED) {
+ WARN(1, "omap_device: %s.%d: %s() called from invalid state %d\n",
+ od->pdev.name, od->pdev.id, __func__, od->_state);
+ return -EINVAL;
+ }
+
+ /* Enable everything if we're enabling this device from scratch */
+ if (od->_state == OMAP_DEVICE_STATE_UNKNOWN)
+ od->pm_lat_level = od->pm_lats_cnt;
+
+ ret = _omap_device_activate(od, IGNORE_WAKEUP_LAT);
+
+ od->dev_wakeup_lat = 0;
+ od->_dev_wakeup_lat_limit = UINT_MAX;
+ od->_state = OMAP_DEVICE_STATE_ENABLED;
+
+ return ret;
+}
+
+/**
+ * omap_device_idle - idle an omap_device
+ * @od: struct omap_device * to idle
+ *
+ * Idle omap_device @od by calling as many .deactivate_func() entries
+ * in the omap_device's pm_lats table as is possible without exceeding
+ * the device's maximum wakeup latency limit, pm_lat_limit. Device
+ * drivers should call this function (through platform_data function
+ * pointers) where they would normally disable clocks after operations
+ * complete, etc.. Returns -EINVAL if the omap_device is not
+ * currently enabled, or passes along the return value of
+ * _omap_device_deactivate().
+ */
+int omap_device_idle(struct platform_device *pdev)
+{
+ int ret;
+ struct omap_device *od;
+
+ od = _find_by_pdev(pdev);
+
+ if (od->_state != OMAP_DEVICE_STATE_ENABLED) {
+ WARN(1, "omap_device: %s.%d: %s() called from invalid state %d\n",
+ od->pdev.name, od->pdev.id, __func__, od->_state);
+ return -EINVAL;
+ }
+
+ ret = _omap_device_deactivate(od, USE_WAKEUP_LAT);
+
+ od->_state = OMAP_DEVICE_STATE_IDLE;
+
+ return ret;
+}
+
+/**
+ * omap_device_shutdown - shut down an omap_device
+ * @od: struct omap_device * to shut down
+ *
+ * Shut down omap_device @od by calling all .deactivate_func() entries
+ * in the omap_device's pm_lats table and then shutting down all of
+ * the underlying omap_hwmods. Used when a device is being "removed"
+ * or a device driver is being unloaded. Returns -EINVAL if the
+ * omap_device is not currently enabled or idle, or passes along the
+ * return value of _omap_device_deactivate().
+ */
+int omap_device_shutdown(struct platform_device *pdev)
+{
+ int ret, i;
+ struct omap_device *od;
+
+ od = _find_by_pdev(pdev);
+
+ if (od->_state != OMAP_DEVICE_STATE_ENABLED &&
+ od->_state != OMAP_DEVICE_STATE_IDLE) {
+ WARN(1, "omap_device: %s.%d: %s() called from invalid state %d\n",
+ od->pdev.name, od->pdev.id, __func__, od->_state);
+ return -EINVAL;
+ }
+
+ ret = _omap_device_deactivate(od, IGNORE_WAKEUP_LAT);
+
+ for (i = 0; i < od->hwmods_cnt; i++)
+ omap_hwmod_shutdown(od->hwmods[i]);
+
+ od->_state = OMAP_DEVICE_STATE_SHUTDOWN;
+
+ return ret;
+}
+
+/**
+ * omap_device_align_pm_lat - activate/deactivate device to match wakeup lat lim
+ * @od: struct omap_device *
+ *
+ * When a device's maximum wakeup latency limit changes, call some of
+ * the .activate_func or .deactivate_func function pointers in the
+ * omap_device's pm_lats array to ensure that the device's maximum
+ * wakeup latency is less than or equal to the new latency limit.
+ * Intended to be called by OMAP PM code whenever a device's maximum
+ * wakeup latency limit changes (e.g., via
+ * omap_pm_set_dev_wakeup_lat()). Returns 0 if nothing needs to be
+ * done (e.g., if the omap_device is not currently idle, or if the
+ * wakeup latency is already current with the new limit) or passes
+ * along the return value of _omap_device_deactivate() or
+ * _omap_device_activate().
+ */
+int omap_device_align_pm_lat(struct platform_device *pdev,
+ u32 new_wakeup_lat_limit)
+{
+ int ret = -EINVAL;
+ struct omap_device *od;
+
+ od = _find_by_pdev(pdev);
+
+ if (new_wakeup_lat_limit == od->dev_wakeup_lat)
+ return 0;
+
+ od->_dev_wakeup_lat_limit = new_wakeup_lat_limit;
+
+ if (od->_state != OMAP_DEVICE_STATE_IDLE)
+ return 0;
+ else if (new_wakeup_lat_limit > od->dev_wakeup_lat)
+ ret = _omap_device_deactivate(od, USE_WAKEUP_LAT);
+ else if (new_wakeup_lat_limit < od->dev_wakeup_lat)
+ ret = _omap_device_activate(od, USE_WAKEUP_LAT);
+
+ return ret;
+}
+
+/**
+ * omap_device_get_pwrdm - return the powerdomain * associated with @od
+ * @od: struct omap_device *
+ *
+ * Return the powerdomain associated with the first underlying
+ * omap_hwmod for this omap_device. Intended for use by core OMAP PM
+ * code. Returns NULL on error or a struct powerdomain * upon
+ * success.
+ */
+struct powerdomain *omap_device_get_pwrdm(struct omap_device *od)
+{
+ /*
+ * XXX Assumes that all omap_hwmod powerdomains are identical.
+ * This may not necessarily be true. There should be a sanity
+ * check in here to WARN() if any difference appears.
+ */
+ if (!od->hwmods_cnt)
+ return NULL;
+
+ return omap_hwmod_get_pwrdm(od->hwmods[0]);
+}
+
+/**
+ * omap_device_get_mpu_rt_va - return the MPU's virtual addr for the hwmod base
+ * @od: struct omap_device *
+ *
+ * Return the MPU's virtual address for the base of the hwmod, from
+ * the ioremap() that the hwmod code does. Only valid if there is one
+ * hwmod associated with this device. Returns NULL if there are zero
+ * or more than one hwmods associated with this omap_device;
+ * otherwise, passes along the return value from
+ * omap_hwmod_get_mpu_rt_va().
+ */
+void __iomem *omap_device_get_rt_va(struct omap_device *od)
+{
+ if (od->hwmods_cnt != 1)
+ return NULL;
+
+ return omap_hwmod_get_mpu_rt_va(od->hwmods[0]);
+}
+
+/*
+ * Public functions intended for use in omap_device_pm_latency
+ * .activate_func and .deactivate_func function pointers
+ */
+
+/**
+ * omap_device_enable_hwmods - call omap_hwmod_enable() on all hwmods
+ * @od: struct omap_device *od
+ *
+ * Enable all underlying hwmods. Returns 0.
+ */
+int omap_device_enable_hwmods(struct omap_device *od)
+{
+ int i;
+
+ for (i = 0; i < od->hwmods_cnt; i++)
+ omap_hwmod_enable(od->hwmods[i]);
+
+ /* XXX pass along return value here? */
+ return 0;
+}
+
+/**
+ * omap_device_idle_hwmods - call omap_hwmod_idle() on all hwmods
+ * @od: struct omap_device *od
+ *
+ * Idle all underlying hwmods. Returns 0.
+ */
+int omap_device_idle_hwmods(struct omap_device *od)
+{
+ int i;
+
+ for (i = 0; i < od->hwmods_cnt; i++)
+ omap_hwmod_idle(od->hwmods[i]);
+
+ /* XXX pass along return value here? */
+ return 0;
+}
+
+/**
+ * omap_device_disable_clocks - disable all main and interface clocks
+ * @od: struct omap_device *od
+ *
+ * Disable the main functional clock and interface clock for all of the
+ * omap_hwmods associated with the omap_device. Returns 0.
+ */
+int omap_device_disable_clocks(struct omap_device *od)
+{
+ int i;
+
+ for (i = 0; i < od->hwmods_cnt; i++)
+ omap_hwmod_disable_clocks(od->hwmods[i]);
+
+ /* XXX pass along return value here? */
+ return 0;
+}
+
+/**
+ * omap_device_enable_clocks - enable all main and interface clocks
+ * @od: struct omap_device *od
+ *
+ * Enable the main functional clock and interface clock for all of the
+ * omap_hwmods associated with the omap_device. Returns 0.
+ */
+int omap_device_enable_clocks(struct omap_device *od)
+{
+ int i;
+
+ for (i = 0; i < od->hwmods_cnt; i++)
+ omap_hwmod_enable_clocks(od->hwmods[i]);
+
+ /* XXX pass along return value here? */
+ return 0;
+}
+
+struct device omap_device_parent = {
+ .init_name = "omap",
+ .parent = &platform_bus,
+};
+
+static int __init omap_device_init(void)
+{
+ return device_register(&omap_device_parent);
+}
+core_initcall(omap_device_init);