/*
* 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 <plat/omap_device.h>
#include <plat/omap_hwmod.h>
/* These parameters are passed to _omap_device_{de,}activate() */
#define USE_WAKEUP_LAT 0
#define IGNORE_WAKEUP_LAT 1
/*
* OMAP_DEVICE_MAGIC: used to determine whether a struct omap_device
* obtained via container_of() is in fact a struct omap_device
*/
#define OMAP_DEVICE_MAGIC 0xf00dcafe
/* 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);
}
/* Public functions for use by core code */
/**
* 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)
{
struct omap_hwmod *oh;
int c = 0;
int i;
for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
c += omap_hwmod_count_resources(oh);
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)
{
struct omap_hwmod *oh;
int c = 0;
int i, r;
for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++) {
r = omap_hwmod_fill_resources(oh, 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;
od->magic = OMAP_DEVICE_MAGIC;
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;
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;
}
/**
* 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);
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;
struct omap_hwmod *oh;
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, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
omap_hwmod_shutdown(oh);
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_is_valid - Check if pointer is a valid omap_device
* @od: struct omap_device *
*
* Return whether struct omap_device pointer @od points to a valid
* omap_device.
*/
bool omap_device_is_valid(struct omap_device *od)
{
return (od && od->magic == OMAP_DEVICE_MAGIC);
}
/**
* 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)
{
struct omap_hwmod *oh;
int i;
for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
omap_hwmod_enable(oh);
/* 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)
{
struct omap_hwmod *oh;
int i;
for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
omap_hwmod_idle(oh);
/* 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)
{
struct omap_hwmod *oh;
int i;
for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
omap_hwmod_disable_clocks(oh);
/* 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)
{
struct omap_hwmod *oh;
int i;
for (i = 0, oh = *od->hwmods; i < od->hwmods_cnt; i++, oh++)
omap_hwmod_enable_clocks(oh);
/* XXX pass along return value here? */
return 0;
}
