freebsd-skq/sys/arm/nvidia/tegra124/tegra124_clk_super.c
mmel a5b629647e TEGRA: Fix CPU frequency switching.
The PLL_X, base CPU frequency source, doesn't have a bypass switch and thus
we must use another frequency source for CPU while changing its frequency.
PLL_P is ideal for this, it runs at 480MHz and CPU can be clocked at this
frequency at any CPU voltage.
2016-04-05 09:20:52 +00:00

266 lines
7.0 KiB
C

/*-
* Copyright (c) 2016 Michal Meloun <mmel@FreeBSD.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rman.h>
#include <machine/bus.h>
#include <dev/extres/clk/clk.h>
#include <gnu/dts/include/dt-bindings/clock/tegra124-car.h>
#include "tegra124_car.h"
/* Flags */
#define SMF_HAVE_DIVIDER_2 1
struct super_mux_def {
struct clknode_init_def clkdef;
uint32_t base_reg;
uint32_t flags;
int src_pllx;
int src_div2;
};
#define PLIST(x) static const char *x[]
#define SM(_id, cn, pl, r, x, d, f) \
{ \
.clkdef.id = _id, \
.clkdef.name = cn, \
.clkdef.parent_names = pl, \
.clkdef.parent_cnt = nitems(pl), \
.clkdef.flags = CLK_NODE_STATIC_STRINGS, \
.base_reg = r, \
.src_pllx = x, \
.src_div2 = d, \
.flags = f, \
}
PLIST(cclk_g_parents) = {
"clk_m", "pllC_out0", "clk_s", "pllM_out0",
"pllP_out0", "pllP_out4", "pllC2_out0", "pllC3_out0",
"pllX_out", NULL, NULL, NULL,
NULL, NULL, NULL,NULL, // "dfllCPU_out0"
};
PLIST(cclk_lp_parents) = {
"clk_m", "pllC_out0", "clk_s", "pllM_out0",
"pllP_out0", "pllP_out4", "pllC2_out0", "pllC3_out0",
"pllX_out", NULL, NULL, NULL,
NULL, NULL, NULL, NULL,
"pllX_out0"
};
PLIST(sclk_parents) = {
"clk_m", "pllC_out1", "pllP_out4", "pllP_out0",
"pllP_out2", "pllC_out0", "clk_s", "pllM_out1",
};
static struct super_mux_def super_mux_def[] = {
SM(TEGRA124_CLK_CCLK_G, "cclk_g", cclk_g_parents, CCLKG_BURST_POLICY, 0, 0, 0),
SM(TEGRA124_CLK_CCLK_LP, "cclk_lp", cclk_lp_parents, CCLKLP_BURST_POLICY, 8, 16, SMF_HAVE_DIVIDER_2),
SM(TEGRA124_CLK_SCLK, "sclk", sclk_parents, SCLK_BURST_POLICY, 0, 0, 0),
};
static int super_mux_init(struct clknode *clk, device_t dev);
static int super_mux_set_mux(struct clknode *clk, int idx);
struct super_mux_sc {
device_t clkdev;
uint32_t base_reg;
int src_pllx;
int src_div2;
uint32_t flags;
int mux;
};
static clknode_method_t super_mux_methods[] = {
/* Device interface */
CLKNODEMETHOD(clknode_init, super_mux_init),
CLKNODEMETHOD(clknode_set_mux, super_mux_set_mux),
CLKNODEMETHOD_END
};
DEFINE_CLASS_1(tegra124_super_mux, tegra124_super_mux_class, super_mux_methods,
sizeof(struct super_mux_sc), clknode_class);
/* Mux status. */
#define SUPER_MUX_STATE_STDBY 0
#define SUPER_MUX_STATE_IDLE 1
#define SUPER_MUX_STATE_RUN 2
#define SUPER_MUX_STATE_IRQ 3
#define SUPER_MUX_STATE_FIQ 4
/* Mux register bits. */
#define SUPER_MUX_STATE_BIT_SHIFT 28
#define SUPER_MUX_STATE_BIT_MASK 0xF
/* State is Priority encoded */
#define SUPER_MUX_STATE_BIT_STDBY 0x00
#define SUPER_MUX_STATE_BIT_IDLE 0x01
#define SUPER_MUX_STATE_BIT_RUN 0x02
#define SUPER_MUX_STATE_BIT_IRQ 0x04
#define SUPER_MUX_STATE_BIT_FIQ 0x08
#define SUPER_MUX_MUX_WIDTH 4
#define SUPER_MUX_LP_DIV2_BYPASS (1 << 16)
static uint32_t
super_mux_get_state(uint32_t reg)
{
reg = (reg >> SUPER_MUX_STATE_BIT_SHIFT) & SUPER_MUX_STATE_BIT_MASK;
if (reg & SUPER_MUX_STATE_BIT_FIQ)
return (SUPER_MUX_STATE_FIQ);
if (reg & SUPER_MUX_STATE_BIT_IRQ)
return (SUPER_MUX_STATE_IRQ);
if (reg & SUPER_MUX_STATE_BIT_RUN)
return (SUPER_MUX_STATE_RUN);
if (reg & SUPER_MUX_STATE_BIT_IDLE)
return (SUPER_MUX_STATE_IDLE);
return (SUPER_MUX_STATE_STDBY);
}
static int
super_mux_init(struct clknode *clk, device_t dev)
{
struct super_mux_sc *sc;
uint32_t reg;
int shift, state;
sc = clknode_get_softc(clk);
DEVICE_LOCK(sc);
RD4(sc, sc->base_reg, &reg);
DEVICE_UNLOCK(sc);
state = super_mux_get_state(reg);
if ((state != SUPER_MUX_STATE_RUN) &&
(state != SUPER_MUX_STATE_IDLE)) {
panic("Unexpected super mux state: %u", state);
}
shift = state * SUPER_MUX_MUX_WIDTH;
sc->mux = (reg >> shift) & ((1 << SUPER_MUX_MUX_WIDTH) - 1);
/*
* CCLKLP uses PLLX/2 as source if LP_DIV2_BYPASS isn't set
* and source mux is set to PLLX.
*/
if (sc->flags & SMF_HAVE_DIVIDER_2) {
if (((reg & SUPER_MUX_LP_DIV2_BYPASS) == 0) &&
(sc->mux == sc->src_pllx))
sc->mux = sc->src_div2;
}
clknode_init_parent_idx(clk, sc->mux);
return(0);
}
static int
super_mux_set_mux(struct clknode *clk, int idx)
{
struct super_mux_sc *sc;
int shift, state;
uint32_t reg, dummy;
sc = clknode_get_softc(clk);
DEVICE_LOCK(sc);
RD4(sc, sc->base_reg, &reg);
state = super_mux_get_state(reg);
if ((state != SUPER_MUX_STATE_RUN) &&
(state != SUPER_MUX_STATE_IDLE)) {
panic("Unexpected super mux state: %u", state);
}
shift = (state - 1) * SUPER_MUX_MUX_WIDTH;
sc->mux = idx;
if (sc->flags & SMF_HAVE_DIVIDER_2) {
if (idx == sc->src_div2) {
idx = sc->src_pllx;
reg &= ~SUPER_MUX_LP_DIV2_BYPASS;
WR4(sc, sc->base_reg, reg);
RD4(sc, sc->base_reg, &dummy);
} else if (idx == sc->src_pllx) {
reg = SUPER_MUX_LP_DIV2_BYPASS;
WR4(sc, sc->base_reg, reg);
RD4(sc, sc->base_reg, &dummy);
}
}
reg &= ~(((1 << SUPER_MUX_MUX_WIDTH) - 1) << shift);
reg |= idx << shift;
WR4(sc, sc->base_reg, reg);
RD4(sc, sc->base_reg, &dummy);
DEVICE_UNLOCK(sc);
return(0);
}
static int
super_mux_register(struct clkdom *clkdom, struct super_mux_def *clkdef)
{
struct clknode *clk;
struct super_mux_sc *sc;
clk = clknode_create(clkdom, &tegra124_super_mux_class,
&clkdef->clkdef);
if (clk == NULL)
return (1);
sc = clknode_get_softc(clk);
sc->clkdev = clknode_get_device(clk);
sc->base_reg = clkdef->base_reg;
sc->src_pllx = clkdef->src_pllx;
sc->src_div2 = clkdef->src_div2;
sc->flags = clkdef->flags;
clknode_register(clkdom, clk);
return (0);
}
void
tegra124_super_mux_clock(struct tegra124_car_softc *sc)
{
int i, rv;
for (i = 0; i < nitems(super_mux_def); i++) {
rv = super_mux_register(sc->clkdom, &super_mux_def[i]);
if (rv != 0)
panic("super_mux_register failed");
}
}