/*
* omap_device implementation
*
*
*
*
* 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(&