>>-----Original Message----- >>From: Kevin Hilman [mailto:khilman@xxxxxxxxxxxxxxxxxxx] >>Sent: Thursday, September 02, 2010 4:22 AM >>To: Gopinath, Thara >>Cc: linux-omap@xxxxxxxxxxxxxxx; paul@xxxxxxxxx; Sripathy, Vishwanath; Sawant, Anand; Cousson, Benoit; >>thomas.petazzoni@xxxxxxxxxxxxxxxxxx >>Subject: Re: [PATCH 01/13] OMAP: Introduce a user list for each voltage domain instance in the >>voltage driver. >> >>Thara Gopinath <thara@xxxxxx> writes: >> >>> This patch introduces a user list of devices associated with each >>> voltage domain instance. The user list is implemented using plist >>> structure with priority node populated with the voltage values. >>> This patch also adds an API which will take in a device and >>> requested voltage as parameters, adds the info to the user list >>> and returns back the maximum voltage requested by all the user >>> devices. This can be used anytime to get the voltage that the >>> voltage domain instance can be transitioned into. >>> >>> Signed-off-by: Thara Gopinath <thara@xxxxxx> >> >>Looking closer at this, keeping track of a list of devices and >>constraints is what the regulator framework does as well. >> >>Before we get too far down this path, we need to start working with >>Thomas Petazzoni to better understand how we can use the regulator >>framework for much of the management levels of the voltage layer. >> >>I'd rather not re-invent some of the management/constraints management >>that could be done by the regulator framework. >> >>Basically, I think >> >> r = regulator_get(dev, voltdm->name) >> regulator_set_voltage(r, volt) >> >>would basially be the equivalent of >> >> omap_voltage_add_userreq(voldm, dev, &volt); >> omap_scale_voltage(voltdm, volt) Hello Kevin, Let me startr off by saying that I am not an expert on regulator framework and hence my assessment below could be wrong. I agree probably regulator framework would be the best place for this but then IMO regulator framework needs a lot of changes to support the kind of use-counting we need in the voltage layer. To start with regulator_get keeps the use counting only for enabling or disabling a regulator. It does not have a mechanism of adding the requested voltage to a list and picking out the highest among the added values. regulator_set_voltage could be used to route the call to omap_scale_voltage but then it is just a wrapper. Regards Thara -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
