Proceedings of the PM SW Workshop Jun 2010

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This wikipage contains proceedings of the PM SW Workshop held in Bangalore on 7-11 Jun, 2010

Contents

[edit] HWMOD Framework Enhancements

[edit] Reset Management Support in HWMOD

[edit] More Granular HWMOD Structures

[edit] Multi-level omap_device_idle

Placeholder for patches from Vibhore to support device latency contraint

[edit] Access to HWMOD Internal Data

[edit] Miscellaneous Issues

[edit] Minutes & Action Items


[edit] Power Domain And Clock Domain Cleanup

Aligned on the following two phase approach

[edit] SRF Replacement - Constraints Part

[edit] Types of Latency Constraints

[edit] Details of Interrupt Latency

[edit] Details of Device Latency

[edit] Proposed Implementation

void omap_pm_set_max_dev_wakeup_lat(struct device *dev, long t)
{
	/*  existing code */	
	1. Look for devices’ power domain (might be multiple step if starting  with general device)
	2. Use device name as identifier for constraint request

	if (t == -1)
		pwrdm_release_wakeup_lat_constraint (pwrdm, lat_dev_name);
	else
		 pwrdm_set_wakeup_lat_constraint (pwrdm, lat_dev_name, t);
}
struct powerdomain {
/* existing entries*/
const u32 wakeup_lat[PWRDM_MAX_PWRSTS-1];
static LIST_HEAD(wakeup_lat_constraint_list);
} 
static struct powerdomain core_44xx_pwrdm = {
.wakeup_lat = {
50,   /* off */
20,   /* ret */ -1 for not supported power state
0,     /* inactive */ Do we have to worry about OSWR?
}
}
pwrdm_set_wakeup_lat_constraint (struct powerdomain *pwrdm, char *lat_dev_name, long lat_us){
	1. If new constraint, add a new entry to wakeup_lat_constraint_list
	2. If already existing, update entries’ latency value
	3. pwrdm_check_for_state_change (pwrdm)
} 
pwrdm_release_wakeup_lat_constraint (struct powerdomain *pwrdm, char   *lat_dev_name){
	1. Remove this devices’ constraint from wakeup_lat_constraint_list
	2. pwrdm_check_for_state_change (pwrdm)
}
pwrdm_check_for_state_change (struct powerdomain *pwrdm){
	1. min_latency = find_min_wakeup_latency_constraint (pwrdm) 
		 //go through the list for minimum latency value
	2. find power state that has latency lower than minimum constraint
		 for (new_state = 0x0; new_state < PWRDM_MAX_PWRSTS; new_state++){
		    if (pwrdm->wakeup_lat[i] < min_latency) break;
		}
	3.  if (pwrdm->state != new_state)
 		    pwrdm_set_next_pwrst (pwrdm, new_state); // existing function to program next state
}

[edit] Minutes & Action Items

.wakeuplat = {
    [FUNC-PWRST-OFF] = 50,
   [FUNC-PWRST-OSWR] = 30,
  [FUNC-PWRST-CSWR] = 5,
  [FUNC-PWRST-ON] = 0,
};
.func_pwrsts = (FUNC_PWRST_OFF | FUNC_PWRST_OSWR | FUNC_PWRST_CSWR |   FUNC_PWRST_ON)
1 << FUNC_PWRST_OFF
pwrdm_wakelat_set_constraint
pwrdm_wakeuplat_remove_constraint
pwrdm_wakeuplat_update_pwrst)


[edit] SRF Replacement - OPP Part

Aligned on using device based OPP approach & maintaining constraints in voltage layer for OPP part of SRF replacement. Sufficient details have been worked out to proceed with the basic DVFS implementation of VDD MPU, VDD IVA & VDD Core voltage domains.

[edit] RFC Patches

Here is a work-in-progress patch that shows work done so far and some of the review comments addressed. Please note that this is in no way completed, compiling, clean patch. It is provided to have a better idea of the changes proposed and discussed.

File:SRF Replacement OPP Part RFC Patch.pdf

[edit] Minutes & Action Items

[edit] Review of Device Driver HWMOD Adaptations

[edit] MUSB

[edit] MMC


[edit] DSS


[edit] DMA

[edit] General Minutes and Action Items

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