Add support for ePWM submodule of PWMSS

ePWM is controlled by sysctl nodes dev.am335x_pwm.N.period,
dev.am335x_pwm.N.dutyA and dev.am335x_pwm.N.dutyB that controls
PWM period and duty cycles for channels A and B respectively.

Period and duty cycle are measured in clock ticks. Default
clock frequency for AM335x PWM subsystem is 100MHz
This commit is contained in:
gonzo 2013-07-04 20:13:22 +00:00
parent d22cbd9996
commit 9a2ff700a4

View File

@ -36,6 +36,7 @@ __FBSDID("$FreeBSD$");
#include <sys/mutex.h>
#include <sys/resource.h>
#include <sys/rman.h>
#include <sys/sysctl.h>
#include <machine/bus.h>
@ -50,6 +51,9 @@ __FBSDID("$FreeBSD$");
#include "am335x_pwm.h"
#include "am335x_scm.h"
/* In ticks */
#define DEFAULT_PWM_PERIOD 1000
#define PWM_LOCK(_sc) mtx_lock(&(_sc)->sc_mtx)
#define PWM_UNLOCK(_sc) mtx_unlock(&(_sc)->sc_mtx)
#define PWM_LOCK_INIT(_sc) mtx_init(&(_sc)->sc_mtx, \
@ -96,15 +100,24 @@ static struct resource_spec am335x_pwm_mem_spec[] = {
#define ECCTL2_TSCTRSTOP_FREERUN (1 << 4)
#define EPWM_TBCTL 0x00
#define TBCTL_FREERUN (2 << 14)
#define TBCTL_PHDIR_UP (1 << 13)
#define TBCTL_PHDIR_DOWN (0 << 13)
#define TBCTL_CLKDIV(x) ((x) << 10)
#define TBCTL_CLKDIV_MASK (3 << 10)
#define TBCTL_HSPCLKDIV(x) ((x) << 7)
#define TBCTL_HSPCLKDIV_MASK (3 << 7)
#define TBCTL_SYNCOSEL_DISABLED (3 << 4)
#define TBCTL_PRDLD_SHADOW (0 << 3)
#define TBCTL_PRDLD_IMMEDIATE (0 << 3)
#define TBCTL_PHSEN_ENABLED (1 << 2)
#define TBCTL_PHSEN_DISABLED (0 << 2)
#define TBCTL_CTRMODE_MASK (3)
#define TBCTL_CTRMODE_UP (0 << 0)
#define TBCTL_CTRMODE_DOWN (1 << 0)
#define TBCTL_CTRMODE_UPDOWN (2 << 0)
#define TBCTL_CTRMODE_FREEZE (3 << 0)
#define EPWM_TBSTS 0x02
#define EPWM_TBPHSHR 0x04
#define EPWM_TBPHS 0x06
@ -130,10 +143,14 @@ static struct resource_spec am335x_pwm_mem_spec[] = {
/* CMPCTL_LOADAMODE_ZERO */
#define EPWM_AQCTLA 0x16
#define EPWM_AQCTLB 0x18
#define AQCTL_CAU_NONE (0 << 0)
#define AQCTL_CAU_CLEAR (1 << 0)
#define AQCTL_CAU_SET (2 << 0)
#define AQCTL_CAU_TOGGLE (3 << 0)
#define AQCTL_CBU_NONE (0 << 8)
#define AQCTL_CBU_CLEAR (1 << 8)
#define AQCTL_CBU_SET (2 << 8)
#define AQCTL_CBU_TOGGLE (3 << 8)
#define AQCTL_CAU_NONE (0 << 4)
#define AQCTL_CAU_CLEAR (1 << 4)
#define AQCTL_CAU_SET (2 << 4)
#define AQCTL_CAU_TOGGLE (3 << 4)
#define AQCTL_ZRO_NONE (0 << 0)
#define AQCTL_ZRO_CLEAR (1 << 0)
#define AQCTL_ZRO_SET (2 << 0)
@ -141,6 +158,15 @@ static struct resource_spec am335x_pwm_mem_spec[] = {
#define EPWM_AQSFRC 0x1a
#define EPWM_AQCSFRC 0x1c
/* Trip-Zone module */
#define EPWM_TZCTL 0x28
#define EPWM_TZFLG 0x2C
/* High-Resolution PWM */
#define EPWM_HRCTL 0x40
#define HRCTL_DELMODE_BOTH 3
#define HRCTL_DELMODE_FALL 2
#define HRCTL_DELMODE_RISE 1
static device_probe_t am335x_pwm_probe;
static device_attach_t am335x_pwm_attach;
static device_detach_t am335x_pwm_detach;
@ -150,6 +176,13 @@ struct am335x_pwm_softc {
struct mtx sc_mtx;
struct resource *sc_mem_res[4];
int sc_id;
/* sysctl for configuration */
struct sysctl_oid *sc_period_oid;
struct sysctl_oid *sc_chanA_oid;
struct sysctl_oid *sc_chanB_oid;
uint32_t sc_pwm_period;
uint32_t sc_pwm_dutyA;
uint32_t sc_pwm_dutyB;
};
static device_method_t am335x_pwm_methods[] = {
@ -208,6 +241,71 @@ am335x_pwm_config_ecas(int unit, int period, int duty)
return (0);
}
static int
am335x_pwm_sysctl_duty(SYSCTL_HANDLER_ARGS)
{
struct am335x_pwm_softc *sc = (struct am335x_pwm_softc*)arg1;
int error;
uint32_t duty;
if (oidp == sc->sc_chanA_oid)
duty = sc->sc_pwm_dutyA;
else
duty = sc->sc_pwm_dutyB;
error = sysctl_handle_int(oidp, &duty, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (duty > sc->sc_pwm_period) {
device_printf(sc->sc_dev, "Duty cycle can't be greater then period\n");
return (EINVAL);
}
PWM_LOCK(sc);
if (oidp == sc->sc_chanA_oid) {
sc->sc_pwm_dutyA = duty;
EPWM_WRITE2(sc, EPWM_CMPA, sc->sc_pwm_dutyA);
}
else {
sc->sc_pwm_dutyB = duty;
EPWM_WRITE2(sc, EPWM_CMPB, sc->sc_pwm_dutyB);
}
PWM_UNLOCK(sc);
return (error);
}
static int
am335x_pwm_sysctl_period(SYSCTL_HANDLER_ARGS)
{
struct am335x_pwm_softc *sc = (struct am335x_pwm_softc*)arg1;
int error;
uint32_t period;
period = sc->sc_pwm_period;
error = sysctl_handle_int(oidp, &period, 0, req);
if (error != 0 || req->newptr == NULL)
return (error);
if (period < 1)
return (EINVAL);
if ((period < sc->sc_pwm_dutyA) || (period < sc->sc_pwm_dutyB)) {
device_printf(sc->sc_dev, "Period can't be less then duty cycle\n");
return (EINVAL);
}
PWM_LOCK(sc);
sc->sc_pwm_period = period;
EPWM_WRITE2(sc, EPWM_TBPRD, period - 1);
PWM_UNLOCK(sc);
return (error);
}
static int
am335x_pwm_probe(device_t dev)
{
@ -227,6 +325,8 @@ am335x_pwm_attach(device_t dev)
uint32_t reg;
phandle_t node;
pcell_t did;
struct sysctl_ctx_list *ctx;
struct sysctl_oid *tree;
sc = device_get_softc(dev);
sc->sc_dev = dev;
@ -252,6 +352,47 @@ am335x_pwm_attach(device_t dev)
reg |= (1 << sc->sc_id);
ti_scm_reg_write_4(SCM_PWMSS_CTRL, reg);
/* Init backlight interface */
ctx = device_get_sysctl_ctx(sc->sc_dev);
tree = device_get_sysctl_tree(sc->sc_dev);
sc->sc_period_oid = SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"period", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
am335x_pwm_sysctl_period, "I", "PWM period");
sc->sc_chanA_oid = SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"dutyA", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
am335x_pwm_sysctl_duty, "I", "Channel A duty cycles");
sc->sc_chanB_oid = SYSCTL_ADD_PROC(ctx, SYSCTL_CHILDREN(tree), OID_AUTO,
"dutyB", CTLTYPE_INT | CTLFLAG_RW, sc, 0,
am335x_pwm_sysctl_duty, "I", "Channel B duty cycles");
/* CONFIGURE EPWM1 */
reg = EPWM_READ2(sc, EPWM_TBCTL);
reg &= ~(TBCTL_CLKDIV_MASK | TBCTL_HSPCLKDIV_MASK);
EPWM_WRITE2(sc, EPWM_TBCTL, reg);
sc->sc_pwm_period = DEFAULT_PWM_PERIOD;
sc->sc_pwm_dutyA = 0;
sc->sc_pwm_dutyB = 0;
EPWM_WRITE2(sc, EPWM_TBPRD, sc->sc_pwm_period - 1);
EPWM_WRITE2(sc, EPWM_CMPA, sc->sc_pwm_dutyA);
EPWM_WRITE2(sc, EPWM_CMPB, sc->sc_pwm_dutyB);
EPWM_WRITE2(sc, EPWM_AQCTLA, (AQCTL_ZRO_SET | AQCTL_CAU_CLEAR));
EPWM_WRITE2(sc, EPWM_AQCTLB, (AQCTL_ZRO_SET | AQCTL_CBU_CLEAR));
/* START EPWM */
reg &= ~TBCTL_CTRMODE_MASK;
reg |= TBCTL_CTRMODE_UP | TBCTL_FREERUN;
EPWM_WRITE2(sc, EPWM_TBCTL, reg);
EPWM_WRITE2(sc, EPWM_TZCTL, 0xf);
reg = EPWM_READ2(sc, EPWM_TZFLG);
return (0);
fail:
PWM_LOCK_DESTROY(sc);