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Add some rudimentary voltage control to go with the rudimentary frequency

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control.  If we have to scale back the frequency due to temperature, it
will help to lower the voltage as well.
This commit is contained in:
ian 2014-02-28 00:26:57 +00:00
parent f029324d5b
commit b517c5faad
1 changed files with 77 additions and 2 deletions
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79
sys/arm/freescale/imx/imx6_anatop.c
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@ -66,6 +66,7 @@ __FBSDID("$FreeBSD$");
#include <dev/ofw/ofw_bus_subr.h>
#include <machine/bus.h>
#include <machine/fdt.h>
#include <arm/freescale/fsl_ocotpreg.h>
#include <arm/freescale/fsl_ocotpvar.h>
@ -85,8 +86,11 @@ struct imx6_anatop_softc {
struct resource *res[2];
uint32_t cpu_curhz;
uint32_t cpu_curmhz;
uint32_t cpu_curmv;
uint32_t cpu_minhz;
uint32_t cpu_minmv;
uint32_t cpu_maxhz;
uint32_t cpu_maxmv;
uint32_t refosc_hz;
void *temp_intrhand;
uint32_t temp_high_val;
@ -103,12 +107,15 @@ struct imx6_anatop_softc {
static struct imx6_anatop_softc *imx6_anatop_sc;
/*
* Table of CPU max frequencies. This is indexed by the max frequency value
* (0-3) from the ocotp CFG3 register.
* Tables of CPU max frequencies and corresponding voltages. This is indexed by
* the max frequency value (0-3) from the ocotp CFG3 register.
*/
static uint32_t imx6_cpu_maxhz_tab[] = {
792000000, 852000000, 996000000, 1200000000
};
static uint32_t imx6_cpu_millivolt_tab[] = {
1150, 1225, 1225, 1275
};
#define TZ_ZEROC 2732 /* deci-Kelvin <-> deci-Celcius offset. */
@ -130,6 +137,64 @@ imx6_anatop_write_4(bus_size_t offset, uint32_t value)
bus_write_4(imx6_anatop_sc->res[MEMRES], offset, value);
}
static void
vdd_set(struct imx6_anatop_softc *sc, int mv)
{
int newtarg, oldtarg;
uint32_t delay, pmureg;
static boolean_t init_done = false;
/*
* The datasheet says VDD_PU and VDD_SOC must be equal, and VDD_ARM
* can't be more than 50mV above or 200mV below them. For now to keep
* things simple we set all three to the same value.
*/
pmureg = imx6_anatop_read_4(IMX6_ANALOG_PMU_REG_CORE);
oldtarg = pmureg & IMX6_ANALOG_PMU_REG0_TARG_MASK;
/* Convert mV to target value. Clamp target to valid range. */
if (mv < 725)
newtarg = 0x00;
else if (mv > 1450)
newtarg = 0x1F;
else
newtarg = (mv - 700) / 25;
/*
* The first time through the 3 voltages might not be equal so use a
* long conservative delay. After that we need to delay 3uS for every
* 25mV step upward. No need to delay at all when lowering.
*/
if (init_done) {
if (newtarg == oldtarg)
return;
else if (newtarg > oldtarg)
delay = (newtarg - oldtarg) * 3;
else
delay = 0;
} else {
delay = 700 / 25 * 3;
init_done = true;
}
/*
* Make the change and wait for it to take effect.
*/
pmureg &= ~(IMX6_ANALOG_PMU_REG0_TARG_MASK |
IMX6_ANALOG_PMU_REG1_TARG_MASK |
IMX6_ANALOG_PMU_REG2_TARG_MASK);
pmureg |= newtarg << IMX6_ANALOG_PMU_REG0_TARG_SHIFT;
pmureg |= newtarg << IMX6_ANALOG_PMU_REG1_TARG_SHIFT;
pmureg |= newtarg << IMX6_ANALOG_PMU_REG2_TARG_SHIFT;
imx6_anatop_write_4(IMX6_ANALOG_PMU_REG_CORE, pmureg);
DELAY(delay);
sc->cpu_curmv = newtarg * 25 + 700;
device_printf(sc->dev, "voltage set to %u\n", sc->cpu_curmv);
}
static inline uint32_t
cpufreq_hz_from_div(struct imx6_anatop_softc *sc, uint32_t div)
{
@ -231,7 +296,9 @@ cpufreq_initialize(struct imx6_anatop_softc *sc)
FSL_OCOTP_CFG3_SPEED_MASK) >> FSL_OCOTP_CFG3_SPEED_SHIFT;
sc->cpu_minhz = cpufreq_actual_hz(sc, imx6_cpu_maxhz_tab[0]);
sc->cpu_minmv = imx6_cpu_millivolt_tab[0];
sc->cpu_maxhz = cpufreq_actual_hz(sc, imx6_cpu_maxhz_tab[cfg3speed]);
sc->cpu_maxmv = imx6_cpu_millivolt_tab[cfg3speed];
/*
* Set the CPU to maximum speed.
@ -241,6 +308,7 @@ cpufreq_initialize(struct imx6_anatop_softc *sc)
* basically assumes that a single core can't overheat before interrupts
* are enabled; empirical testing shows that to be a safe assumption.
*/
vdd_set(sc, sc->cpu_maxmv);
cpufreq_set_clock(sc, sc->cpu_maxhz);
device_printf(sc->dev, "CPU frequency %uMHz\n", sc->cpu_curmhz);
}
@ -321,6 +389,7 @@ tempmon_gofast(struct imx6_anatop_softc *sc)
{
if (sc->cpu_curhz < sc->cpu_maxhz) {
vdd_set(sc, sc->cpu_maxmv);
cpufreq_set_clock(sc, sc->cpu_maxhz);
}
}
@ -331,6 +400,7 @@ tempmon_goslow(struct imx6_anatop_softc *sc)
if (sc->cpu_curhz > sc->cpu_minhz) {
cpufreq_set_clock(sc, sc->cpu_minhz);
vdd_set(sc, sc->cpu_minmv);
}
}
@ -451,6 +521,11 @@ imx6_anatop_attach(device_t dev)
if (err != 0)
goto out;
SYSCTL_ADD_UINT(device_get_sysctl_ctx(sc->dev),
SYSCTL_CHILDREN(device_get_sysctl_tree(sc->dev)),
OID_AUTO, "cpu_voltage", CTLFLAG_RD,
&sc->cpu_curmv, 0, "Current CPU voltage in millivolts");
imx6_anatop_sc = sc;
/*