Menon, Nishanth had written, on 11/19/2009 08:16 PM, the following:
Kevin Hilman had written, on 11/19/2009 07:31 PM, the following:
Nishanth Menon <nm@xxxxxx> writes:
Menon, Nishanth had written, on 11/15/2009 08:54 AM, the following:
[...]
Thanks for a thorough review and the new ideas. I will do a proposal
later tomorrow to aggregate and provide a common solution I hope. some
views follow.
Here it is inlined:
/*
* OMAP OPP Interface
*
* Copyright (C) 2009 Texas Instruments Incorporated.
* Nishanth Menon
* Copyright (C) 2009 Deep Root Systems, LLC.
* Kevin Hilman
*
* 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.
*/
#ifndef __ASM_ARM_OMAP_OPP_H
#ifndef __ASM_ARM_OMAP_OPP_H
/**
* struct omap_opp - OMAP OPP description structure
* @enabled: true/false - marking this OPP as enabled/disabled
* @rate: Frequency in hertz
* @opp_id: (DEPRECATED) opp identifier
* @vsel: Voltage in volt processor level(this usage is
* DEPRECATED to use Voltage in millivolts in future)
* mV= (vsel * 12.5) + 600
*
* This structure stores the OPP information for a given domain.
* Due to legacy reasons, this structure is currently exposed and
* will soon be removed elsewhere and will only be used as a handle
* from the OPP internal referencing mechanism
*/
struct omap_opp {
bool enabled;
unsigned long rate;
u8 opp_id;
u16 vsel;
};
/**
* opp_get_voltage - Gets the voltage corresponding to an opp
* @m_volt: Voltage in millivolts corresponding to an opp
* @opp: opp for which voltage has to be returned for
*
* Return 0 and the voltage in milli volt corresponding to the opp,
* else return the corresponding error value.
*/
int opp_get_voltage(u16 *m_volt, const struct omap_opp *opp);
/**
* opp_get_freq - Gets the frequency corresponding to an opp
* @freq: Frequency in hertz corresponding to an opp
* @opp: opp for which frequency has to be returned for
*
* Return 0 and the frequency in hertz corresponding to the opp,
* else return the corresponding error value.
*/
int opp_get_freq(unsigned long *freq, const struct omap_opp *opp);
/**
* opp_is_valid - Verifies if a given frequency is enabled in the opp list
* @opp: Pointer to opp returned if opp match is achieved
* @oppl: opp list
* @freq: Frequency in hertz to check for
*
* Searches the OPP list to find if the provided frequency is an enabled
* frequency. If a match is achieved, it returns 0 and the pointer to
the opp
* is returned, else a corresponding error value is returned.
*/
int opp_is_valid(struct omap_opp **opp, const struct omap_opp *oppl,
const unsigned long freq);
/**
* opp_has_freq - Checks if a frequency is exists(enabled/disabled) in
opp list
* @opp: Pointer to opp returned if opp match is achieved
* @oppl: opp list
* @freq: Frequency in hertz to check for
*
* Searches the OPP list to find a frequency. This is a more generic
function
* than the opp_is_valid since it searches for both enabled/disabled
* frequencies.
*
* This function may be used by detection logic to enable a disabled OPP as
* all other search functions work on enabled OPPs only.
*/
int opp_has_freq(struct omap_opp **opp, const struct omap_opp *oppl,
const unsigned long freq);
/**
* opp_get_opp_count - Get number of opps enabled in the opp list
* @num: returns the number of opps
* @oppl: opp list
*
* This functions returns 0 and the number of opps are updated in num if
* success, else returns corresponding error value.
*/
int opp_get_opp_count(u8 *num, const struct omap_opp *oppl);
/**
* opp_get_higher_opp - search for the next highest opp in the list
* @opp: pointer to the opp
* @freq: frequency to start the search on
* @oppl: opp list to search on
*
* Searches for the higher *enabled* OPP than a starting freq/opp
* Decision of start condition:
* if *opp is NULL, *freq is checked (usually the start condition)
* if *opp is populated, *freq is ignored
* Returns 0 and *opp and *freq is populated with the next highest match,
* else returns corresponding error value.
*
* Example usage:
* * print a all frequencies ascending order *
* unsigned long freq = 0;
* struct omap_opp *opp = NULL;
* while(!opp_get_higher_opp(&opp, &freq, oppl))
* pr_info("%ld ", freq);
* NOTE: if we set freq as 0, we get the lowest enabled frequency
*/
int opp_get_higher_opp(struct omap_opp **opp, unsigned long *freq,
const struct omap_opp *oppl);
/**
* opp_get_lower_opp - search for the next lower opp in the list
* @opp: pointer to the opp
* @freq: frequency to start the search on
* @oppl: opp list to search on
*
* Search for the lower *enabled* OPP than a starting freq/opp
* Decision of start condition:
* if *opp is NULL, *freq is checked (usually the start condition)
* if *opp is populated, *freq is ignored
* Returns 0 and *opp and *freq is populated with the next lowest match,
* else returns corresponding error value.
*
* Example usage:
* * print a all frequencies in descending order *
* unsigned long freq = ULONG_MAX;
* struct omap_opp *opp = NULL;
* while(!opp_get_lower_opp(&opp, &freq, oppl))
* pr_info("%ld ", freq);
* NOTE: if we set freq as ULONG_MAX, we get the highest enabled frequency
*/
int opp_get_lower_opp(struct omap_opp **opp, unsigned long *freq,
const struct omap_opp *oppl);
/**
* struct omap_opp_def - OMAP OPP Definition
* @enabled: True/false - is this OPP enabled/disabled by default
* @freq: Frequency in hertz corresponding to this OPP
* @m_volt: Nominal voltage in millivolts corresponding to this OPP
*
* OMAP SOCs from OMAP3 onwards have a standard set of tuples consisting
* of frequency and voltage pairs that the device will support. This is
* Operating Point. However, the actual definitions of OMAP Operating Point
* varies over silicon within the same family of devices. For a specific
* domain, you can have a set of {frequency, voltage} pairs and this is
denoted
* by an array of omap_opp_def. As the kernel boots and more information is
* available, a set of these are activated based on the precise nature of
* device the kernel boots up on.
*
* NOTE: A disabled opp from the omap_opp_def table may be enabled as
part of
* runtime logic. It is discouraged to enable/disable the OPP unless
they are
* done as part of OPP registration sequence.
*/
struct omap_opp_def {
bool enabled;
unsigned long freq;
u16 m_volt;
};
/**
* opp_init - Initialize an OPP table from the initial table definition
* @oppl: Returned back to caller as the opp list to reference the OPP
* @opp_defs: Array of omap_opp_def to describe the OPP. This list
should be
* 0 terminated.
*
* This function creates the internal datastructure representing the
OPP list
* from an initial definition table. this handle is then used for further
* validation, search, modification operations on the OPP list.
*
* This function returns 0 and the pointer to the allocated list
through oppl if
* success, else corresponding error value. Caller should NOT free the
oppl.
* opps_defs can be freed after use.
*/
int opp_init(struct omap_opp **oppl, const struct omap_opp_def *opp_defs);
/**
* opp_enable - Enable or disable a specific OPP
* @opp: pointer to opp
* @freq: frequency in hertz
* @enable: true/false to enable/disable that specific OPP
*
* Enables/disables a provided freq in the opp list. If the operation
is valid,
* this returns 0, else the corresponding error value.
*
* OPP used here is from the the opp_is_valid/opp_has_freq or other search
* functions
*/
int opp_enable(const struct omap_opp *opp, const unsigned int freq);
#endif /* __ASM_ARM_OMAP_OPP_H */
--
Regards,
Nishanth Menon
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