zephyr/drivers/pwm/pwm_cc13xx_cc26xx_timer.c

242 lines
6.8 KiB
C

/*
* Copyright (c) 2023 Zephyr Project
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT ti_cc13xx_cc26xx_timer_pwm
#include <zephyr/drivers/i2c.h>
#include <zephyr/drivers/pinctrl.h>
#include <zephyr/drivers/pwm.h>
#include <driverlib/gpio.h>
#include <driverlib/prcm.h>
#include <driverlib/timer.h>
#include <inc/hw_memmap.h>
#include <inc/hw_types.h>
#include <ti/drivers/Power.h>
#include <ti/drivers/power/PowerCC26XX.h>
#include <zephyr/logging/log.h>
#define LOG_MODULE_NAME pwm_cc13xx_cc26xx_timer
LOG_MODULE_REGISTER(LOG_MODULE_NAME, CONFIG_PWM_LOG_LEVEL);
/* TODO: Clock frequency can be settable via KConfig, see TOP:PRCM:GPTCLKDIV */
#define CPU_FREQ ((uint32_t)DT_PROP(DT_PATH(cpus, cpu_0), clock_frequency))
/* GPT peripherals in 16 bit mode have maximum 24 counter bits incl. the
* prescaler. Count is set to (2^24 - 2) to allow for a glitch free 100% duty
* cycle at max. period count.
*/
#define PWM_COUNT_MAX 0xFFFFFE
#define PWM_INITIAL_PERIOD PWM_COUNT_MAX
#define PWM_INITIAL_DUTY 0U /* initially off */
struct pwm_cc13xx_cc26xx_data {
};
struct pwm_cc13xx_cc26xx_config {
const uint32_t gpt_base; /* GPT register base address */
const struct pinctrl_dev_config *pcfg;
LOG_INSTANCE_PTR_DECLARE(log);
};
static void write_value(const struct pwm_cc13xx_cc26xx_config *config, uint32_t value,
uint32_t prescale_register, uint32_t value_register)
{
/* Upper byte represents the prescaler value. */
uint8_t prescaleValue = 0xff & (value >> 16);
HWREG(config->gpt_base + prescale_register) = prescaleValue;
/* The remaining bytes represent the load / match value. */
HWREG(config->gpt_base + value_register) = value & 0xffff;
}
static int set_period_and_pulse(const struct pwm_cc13xx_cc26xx_config *config, uint32_t period,
uint32_t pulse)
{
uint32_t match_value = pulse;
if (pulse == 0U) {
TimerDisable(config->gpt_base, TIMER_B);
#ifdef CONFIG_PM
Power_releaseConstraint(PowerCC26XX_DISALLOW_STANDBY);
#endif
match_value = period + 1;
}
/* Fail if period is out of range */
if ((period > PWM_COUNT_MAX) || (period == 0)) {
LOG_ERR("Period (%d) is out of range.", period);
return -EINVAL;
}
/* Compare to new period and fail if invalid */
if (period < (match_value - 1) || (match_value < 0)) {
LOG_ERR("Period (%d) is shorter than pulse (%d).", period, pulse);
return -EINVAL;
}
/* Store new period and update timer */
write_value(config, period, GPT_O_TBPR, GPT_O_TBILR);
write_value(config, match_value, GPT_O_TBPMR, GPT_O_TBMATCHR);
if (pulse > 0U) {
#ifdef CONFIG_PM
Power_setConstraint(PowerCC26XX_DISALLOW_STANDBY);
#endif
TimerEnable(config->gpt_base, TIMER_B);
}
LOG_DBG("Period and pulse successfully set.");
return 0;
}
static int set_cycles(const struct device *dev, uint32_t channel, uint32_t period, uint32_t pulse,
pwm_flags_t flags)
{
const struct pwm_cc13xx_cc26xx_config *config = dev->config;
if (channel != 0) {
return -EIO;
}
set_period_and_pulse(config, period, pulse);
return 0;
}
static int get_cycles_per_sec(const struct device *dev, uint32_t channel, uint64_t *cycles)
{
if (channel > 0) {
return -EIO;
}
if (cycles) {
*cycles = CPU_FREQ;
}
return 0;
}
static const struct pwm_driver_api pwm_driver_api = {
.set_cycles = set_cycles,
.get_cycles_per_sec = get_cycles_per_sec,
};
#ifdef CONFIG_PM
static int get_timer_inst_number(const struct pwm_cc13xx_cc26xx_config *config)
{
switch (config->gpt_base) {
case GPT0_BASE:
return 0;
case GPT1_BASE:
return 1;
case GPT2_BASE:
return 2;
case GPT3_BASE:
return 3;
default:
__ASSERT_UNREACHABLE;
}
}
#else
static int get_timer_peripheral(const struct pwm_cc13xx_cc26xx_config *config)
{
switch (config->gpt_base) {
case GPT0_BASE:
return PRCM_PERIPH_TIMER0;
case GPT1_BASE:
return PRCM_PERIPH_TIMER1;
case GPT2_BASE:
return PRCM_PERIPH_TIMER2;
case GPT3_BASE:
return PRCM_PERIPH_TIMER3;
default:
__ASSERT_UNREACHABLE;
}
}
#endif /* CONFIG_PM */
static int init_pwm(const struct device *dev)
{
const struct pwm_cc13xx_cc26xx_config *config = dev->config;
pinctrl_soc_pin_t pin = config->pcfg->states[0].pins[0];
int ret;
#ifdef CONFIG_PM
/* Set dependency on gpio resource to turn on power domains */
Power_setDependency(get_timer_inst_number(config));
#else
/* Enable peripheral power domain. */
PRCMPowerDomainOn(PRCM_DOMAIN_PERIPH);
/* Enable GPIO peripheral. */
PRCMPeripheralRunEnable(get_timer_peripheral(config));
/* Load PRCM settings. */
PRCMLoadSet();
while (!PRCMLoadGet()) {
continue;
}
#endif /* CONFIG_PM */
ret = pinctrl_apply_state(config->pcfg, PINCTRL_STATE_DEFAULT);
if (ret < 0) {
LOG_ERR("failed to setup PWM pinctrl");
return ret;
}
/* Configures the PWM idle output level.
*
* TODO: Make PWM idle high/low configurable via custom DT PWM flag.
*/
GPIO_writeDio(pin.pin, 0);
GPIO_setOutputEnableDio(pin.pin, GPIO_OUTPUT_ENABLE);
/* Peripheral should not be accessed until power domain is on. */
while (PRCMPowerDomainsAllOn(PRCM_DOMAIN_PERIPH) != PRCM_DOMAIN_POWER_ON) {
continue;
}
TimerDisable(config->gpt_base, TIMER_B);
HWREG(config->gpt_base + GPT_O_CFG) = GPT_CFG_CFG_16BIT_TIMER;
/* Stall timer when debugging.
*
* TODO: Make debug stall configurable via custom DT prop.
*/
HWREG(config->gpt_base + GPT_O_CTL) |= GPT_CTL_TBSTALL;
/* TODO: Make PWM polarity configurable via DT PWM flag. */
HWREG(config->gpt_base + GPT_O_TBMR) = GPT_TBMR_TBAMS_PWM | GPT_TBMR_TBMRSU_TOUPDATE |
GPT_TBMR_TBPWMIE_EN | GPT_TBMR_TBMR_PERIODIC;
set_period_and_pulse(config, PWM_INITIAL_PERIOD, PWM_INITIAL_DUTY);
return 0;
}
#define DT_TIMER(idx) DT_INST_PARENT(idx)
#define DT_TIMER_BASE_ADDR(idx) (DT_REG_ADDR(DT_TIMER(idx)))
#define PWM_DEVICE_INIT(idx) \
PINCTRL_DT_INST_DEFINE(idx); \
LOG_INSTANCE_REGISTER(LOG_MODULE_NAME, idx, CONFIG_PWM_LOG_LEVEL); \
static const struct pwm_cc13xx_cc26xx_config pwm_cc13xx_cc26xx_##idx##_config = { \
.gpt_base = DT_TIMER_BASE_ADDR(idx), \
.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(idx), \
LOG_INSTANCE_PTR_INIT(log, LOG_MODULE_NAME, idx)}; \
\
static struct pwm_cc13xx_cc26xx_data pwm_cc13xx_cc26xx_##idx##_data; \
\
DEVICE_DT_INST_DEFINE(idx, init_pwm, NULL, &pwm_cc13xx_cc26xx_##idx##_data, \
&pwm_cc13xx_cc26xx_##idx##_config, POST_KERNEL, \
CONFIG_PWM_INIT_PRIORITY, &pwm_driver_api)
DT_INST_FOREACH_STATUS_OKAY(PWM_DEVICE_INIT);