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/* $OpenBSD: imxpwm.c,v 1.1 2020/03/27 16:53:06 patrick Exp $ */
/*
* Copyright (c) 2018-2020 Patrick Wildt <patrick@blueri.se>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/device.h>
#include <sys/sysctl.h>
#include <machine/bus.h>
#include <machine/fdt.h>
#include <dev/ofw/openfirm.h>
#include <dev/ofw/fdt.h>
#include <dev/ofw/ofw_clock.h>
#include <dev/ofw/ofw_pinctrl.h>
#include <dev/ofw/ofw_misc.h>
#define PWM_CR 0x00
#define PWM_CR_EN (1 << 0)
#define PWM_CR_SWR (1 << 3)
#define PWM_CR_CLKSRC_IPG (1 << 16)
#define PWM_CR_CLKSRC_IPG_HIGH (2 << 16)
#define PWM_CR_DBGEN (1 << 22)
#define PWM_CR_WAITEN (1 << 23)
#define PWM_CR_DOZEEN (1 << 24)
#define PWM_CR_PRESCALER(x) ((((x) - 1) & 0xfff) << 4)
#define PWM_CR_PRESCALER_SHIFT 4
#define PWM_CR_PRESCALER_MASK 0xfff
#define PWM_SR 0x04
#define PWM_SR_FIFOAV_4WORDS 0x4
#define PWM_SR_FIFOAV_MASK 0x7
#define PWM_SAR 0x0c
#define PWM_PR 0x10
#define PWM_PR_MAX 0xfffe
#define NS_PER_S 1000000000
#define HREAD4(sc, reg) \
(bus_space_read_4((sc)->sc_iot, (sc)->sc_ioh, (reg)))
#define HWRITE4(sc, reg, val) \
bus_space_write_4((sc)->sc_iot, (sc)->sc_ioh, (reg), (val))
#define HSET4(sc, reg, bits) \
HWRITE4((sc), (reg), HREAD4((sc), (reg)) | (bits))
#define HCLR4(sc, reg, bits) \
HWRITE4((sc), (reg), HREAD4((sc), (reg)) & ~(bits))
struct imxpwm_softc {
struct device sc_dev;
bus_space_tag_t sc_iot;
bus_space_handle_t sc_ioh;
uint32_t sc_dcycles;
uint32_t sc_clkin;
struct pwm_device sc_pd;
};
int imxpwm_match(struct device *, void *, void *);
void imxpwm_attach(struct device *, struct device *, void *);
struct cfattach imxpwm_ca = {
sizeof(struct imxpwm_softc), imxpwm_match, imxpwm_attach
};
struct cfdriver imxpwm_cd = {
NULL, "imxpwm", DV_DULL
};
int imxpwm_get_state(void *, uint32_t *, struct pwm_state *);
int imxpwm_set_state(void *, uint32_t *, struct pwm_state *);
int
imxpwm_match(struct device *parent, void *match, void *aux)
{
struct fdt_attach_args *faa = aux;
return OF_is_compatible(faa->fa_node, "fsl,imx27-pwm");
}
void
imxpwm_attach(struct device *parent, struct device *self, void *aux)
{
struct imxpwm_softc *sc = (struct imxpwm_softc *)self;
struct fdt_attach_args *faa = aux;
if (faa->fa_nreg < 1)
return;
sc->sc_clkin = clock_get_frequency(faa->fa_node, "per");
if (sc->sc_clkin == 0) {
printf(": no clock\n");
return;
}
sc->sc_iot = faa->fa_iot;
if (bus_space_map(sc->sc_iot, faa->fa_reg[0].addr,
faa->fa_reg[0].size, 0, &sc->sc_ioh)) {
printf(": can't map registers");
return;
}
printf("\n");
pinctrl_byname(faa->fa_node, "default");
clock_enable_all(faa->fa_node);
reset_deassert_all(faa->fa_node);
sc->sc_pd.pd_node = faa->fa_node;
sc->sc_pd.pd_cookie = sc;
sc->sc_pd.pd_get_state = imxpwm_get_state;
sc->sc_pd.pd_set_state = imxpwm_set_state;
pwm_register(&sc->sc_pd);
}
int
imxpwm_get_state(void *cookie, uint32_t *cells, struct pwm_state *ps)
{
struct imxpwm_softc *sc = cookie;
uint64_t dcycles, pcycles, prescale, pwmclk;
int enabled = 0;
prescale = ((HREAD4(sc, PWM_CR) >> PWM_CR_PRESCALER_SHIFT) &
PWM_CR_PRESCALER_MASK) + 1;
pwmclk = (sc->sc_clkin + (prescale / 2)) / prescale;
if (pwmclk == 0)
return EINVAL;
if (HREAD4(sc, PWM_CR) & PWM_CR_EN)
enabled = 1;
pcycles = HREAD4(sc, PWM_PR);
if (pcycles >= PWM_PR_MAX)
pcycles = PWM_PR_MAX;
pcycles = (pcycles + 2) * NS_PER_S;
pcycles = (pcycles + (pwmclk / 2)) / pwmclk;
dcycles = sc->sc_dcycles;
if (enabled)
dcycles = HREAD4(sc, PWM_SAR);
dcycles = dcycles * NS_PER_S;
dcycles = (dcycles + (pwmclk / 2)) / pwmclk;
memset(ps, 0, sizeof(struct pwm_state));
ps->ps_period = pcycles;
ps->ps_pulse_width = dcycles;
ps->ps_enabled = enabled;
return 0;
}
int
imxpwm_set_state(void *cookie, uint32_t *cells, struct pwm_state *ps)
{
struct imxpwm_softc *sc = cookie;
uint64_t dcycles, pcycles, prescale;
int i;
if (ps->ps_enabled) {
pcycles = sc->sc_clkin;
pcycles = (pcycles * ps->ps_period) / NS_PER_S;
prescale = pcycles / 0x10000 + 1;
if (ps->ps_period == 0 || prescale == 0)
return EINVAL;
pcycles = pcycles / prescale;
dcycles = (pcycles * ps->ps_pulse_width) / ps->ps_period;
if (pcycles > 2)
pcycles -= 2;
else
pcycles = 0;
}
/* disable and flush fifo */
HCLR4(sc, PWM_CR, PWM_CR_EN);
HWRITE4(sc, PWM_CR, PWM_CR_SWR);
for (i = 0; i < 5; i++) {
delay(1000);
if ((HREAD4(sc, PWM_CR) & PWM_CR_SWR) == 0)
break;
}
if (i == 5) {
printf("%s: reset timeout\n", sc->sc_dev.dv_xname);
return ETIMEDOUT;
}
if (ps->ps_enabled) {
HWRITE4(sc, PWM_SAR, dcycles);
HWRITE4(sc, PWM_PR, pcycles);
sc->sc_dcycles = dcycles;
HWRITE4(sc, PWM_CR, PWM_CR_PRESCALER(prescale) |
PWM_CR_DOZEEN | PWM_CR_WAITEN |
PWM_CR_DBGEN | PWM_CR_CLKSRC_IPG_HIGH |
PWM_CR_EN);
}
return 0;
}
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