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ARM: OMAP3+: voltage: use oscillator data to calculate setup times

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We now use the previously defined oscillator setup / shutdown times
to calculate the register values for CLKSETUP.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>
This commit is contained in:
Tero Kristo 2012-09-25 19:33:41 +03:00 committed by Kevin Hilman
parent 085b302500
commit d68ff977b8
1 changed files with 62 additions and 0 deletions
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62
arch/arm/mach-omap2/vc.c
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@ -11,13 +11,19 @@
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/bug.h>
#include <linux/io.h>
#include <asm/div64.h>
#include "iomap.h"
#include "soc.h"
#include "voltage.h"
#include "vc.h"
#include "prm-regbits-34xx.h"
#include "prm-regbits-44xx.h"
#include "prm44xx.h"
#include "pm.h"
#include "scrm44xx.h"
/**
* struct omap_vc_channel_cfg - describe the cfg_channel bitfield
@ -204,6 +210,18 @@ int omap_vc_bypass_scale(struct voltagedomain *voltdm,
return 0;
}
/* Convert microsecond value to number of 32kHz clock cycles */
static inline u32 omap_usec_to_32k(u32 usec)
{
return DIV_ROUND_UP_ULL(32768ULL * (u64)usec, 1000000ULL);
}
/* Set oscillator setup time for omap3 */
static void omap3_set_clksetup(u32 usec, struct voltagedomain *voltdm)
{
voltdm->write(omap_usec_to_32k(usec), OMAP3_PRM_CLKSETUP_OFFSET);
}
/**
* omap3_set_i2c_timings - sets i2c sleep timings for a channel
* @voltdm: channel to configure
@ -220,6 +238,12 @@ static void omap3_set_i2c_timings(struct voltagedomain *voltdm, bool off_mode)
unsigned long voltsetup1;
u32 tgt_volt;
/*
* Oscillator is shut down only if we are using sys_off_mode pad,
* thus we set a minimal setup time here
*/
omap3_set_clksetup(1, voltdm);
if (off_mode)
tgt_volt = voltdm->vc_param->off;
else
@ -260,6 +284,7 @@ static void omap3_set_off_timings(struct voltagedomain *voltdm)
unsigned long voltsetup2;
unsigned long voltsetup2_old;
u32 val;
u32 tstart, tshut;
/* check if sys_off_mode is used to control off-mode voltages */
val = voltdm->read(OMAP3_PRM_VOLTCTRL_OFFSET);
@ -269,6 +294,9 @@ static void omap3_set_off_timings(struct voltagedomain *voltdm)
return;
}
omap_pm_get_oscillator(&tstart, &tshut);
omap3_set_clksetup(tstart, voltdm);
clksetup = voltdm->read(OMAP3_PRM_CLKSETUP_OFFSET);
/* voltsetup 2 in us */
@ -364,6 +392,30 @@ static u32 omap4_calc_volt_ramp(struct voltagedomain *voltdm, u32 voltage_diff)
(cycles << OMAP4430_RAMP_UP_COUNT_SHIFT);
}
/**
* omap4_usec_to_val_scrm - convert microsecond value to SCRM module bitfield
* @usec: microseconds
* @shift: number of bits to shift left
* @mask: bitfield mask
*
* Converts microsecond value to OMAP4 SCRM bitfield. Bitfield is
* shifted to requested position, and checked agains the mask value.
* If larger, forced to the max value of the field (i.e. the mask itself.)
* Returns the SCRM bitfield value.
*/
static u32 omap4_usec_to_val_scrm(u32 usec, int shift, u32 mask)
{
u32 val;
val = omap_usec_to_32k(usec) << shift;
/* Check for overflow, if yes, force to max value */
if (val > mask)
val = mask;
return val;
}
/**
* omap4_set_timings - set voltage ramp timings for a channel
* @voltdm: channel to configure
@ -376,6 +428,7 @@ static void omap4_set_timings(struct voltagedomain *voltdm, bool off_mode)
u32 val;
u32 ramp;
int offset;
u32 tstart, tshut;
if (off_mode) {
ramp = omap4_calc_volt_ramp(voltdm,
@ -397,6 +450,15 @@ static void omap4_set_timings(struct voltagedomain *voltdm, bool off_mode)
val |= ramp << OMAP4430_RAMP_UP_COUNT_SHIFT;
voltdm->write(val, offset);
omap_pm_get_oscillator(&tstart, &tshut);
val = omap4_usec_to_val_scrm(tstart, OMAP4_SETUPTIME_SHIFT,
OMAP4_SETUPTIME_MASK);
val |= omap4_usec_to_val_scrm(tshut, OMAP4_DOWNTIME_SHIFT,
OMAP4_DOWNTIME_MASK);
__raw_writel(val, OMAP4_SCRM_CLKSETUPTIME);
}
/* OMAP4 specific voltage init functions */