drivers: pwm: add pwm driver for rpi_pico

Add pwm driver implementation for rpi pico family.
Adds myself as codeowner of drivers/pwm/*rpi_pico*

Signed-off-by: Joep Buruma <burumaj50@gmail.com>
This commit is contained in:
Joep Buruma 2022-02-18 21:16:04 +01:00 committed by Carles Cufí
commit 7e0fff24c7
9 changed files with 211 additions and 2 deletions

View file

@ -344,6 +344,7 @@
/drivers/ps2/*xec* @franciscomunoz @sjvasanth1
/drivers/ps2/*npcx* @MulinChao @WealianLiao @ChiHuaL
/drivers/pwm/*b91* @andy-liu-telink
/drivers/pwm/*rpi_pico* @burumaj
/drivers/pwm/*rv32m1* @henrikbrixandersen
/drivers/pwm/*sam0* @nzmichaelh
/drivers/pwm/*stm32* @gmarull

View file

@ -25,6 +25,7 @@ zephyr_library_sources_ifdef(CONFIG_PWM_MCUX_PWT pwm_mcux_pwt.c)
zephyr_library_sources_ifdef(CONFIG_PWM_GECKO pwm_gecko.c)
zephyr_library_sources_ifdef(CONFIG_PWM_GD32 pwm_gd32.c)
zephyr_library_sources_ifdef(CONFIG_PWM_TEST pwm_test.c)
zephyr_library_sources_ifdef(CONFIG_PWM_RPI_PICO pwm_rpi_pico.c)
zephyr_library_sources_ifdef(CONFIG_USERSPACE pwm_handlers.c)
zephyr_library_sources_ifdef(CONFIG_PWM_CAPTURE pwm_capture.c)

View file

@ -73,4 +73,6 @@ source "drivers/pwm/Kconfig.gd32"
source "drivers/pwm/Kconfig.test"
source "drivers/pwm/Kconfig.rpi_pico"
endif # PWM

View file

@ -0,0 +1,14 @@
# Copyright (c) 2022, Joep Buruma
# SPDX-License-Identifier: Apache-2.0
# Workaround for not being able to have commas in macro arguments
DT_COMPAT_RPI_PICO_PWM := raspberrypi,pico-pwm
config PWM_RPI_PICO
bool "RPi Pico PWM"
default $(dt_compat_enabled,$(DT_COMPAT_RPI_PICO_PWM))
depends on SOC_SERIES_RP2XXX
depends on RESET
select PICOSDK_USE_PWM
help
Enable PWM driver for RPi Pico family of MCUs

182
drivers/pwm/pwm_rpi_pico.c Normal file
View file

@ -0,0 +1,182 @@
/*
* Copyright (c) 2022, Joep Buruma
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT raspberrypi_pico_pwm
#include <zephyr/device.h>
#include <zephyr/drivers/pwm.h>
#include <zephyr/drivers/pinctrl.h>
#include <zephyr/drivers/reset.h>
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(pwm_rpi_pico, CONFIG_PWM_LOG_LEVEL);
/* pico-sdk includes */
#include <hardware/pwm.h>
#include <hardware/structs/pwm.h>
#define PWM_RPI_PICO_COUNTER_TOP_MAX UINT16_MAX
#define PWM_RPI_NUM_CHANNELS (16U)
struct pwm_rpi_slice_config {
uint8_t integral;
uint8_t frac;
bool phase_correct;
};
struct pwm_rpi_config {
/*
* pwm_controller is the start address of the pwm peripheral.
*/
pwm_hw_t *pwm_controller;
struct pwm_rpi_slice_config slice_configs[NUM_PWM_SLICES];
const struct pinctrl_dev_config *pcfg;
const struct reset_dt_spec reset;
};
static float pwm_rpi_get_clkdiv(const struct device *dev, int slice)
{
const struct pwm_rpi_config *cfg = dev->config;
/* the divider is a fixed point 8.4 convert to float for use in pico-sdk */
return (float)cfg->slice_configs[slice].integral +
(float)cfg->slice_configs[slice].frac / 16.0;
}
static inline uint32_t pwm_rpi_channel_to_slice(uint32_t channel)
{
return channel / 2;
}
static inline uint32_t pwm_rpi_channel_to_pico_channel(uint32_t channel)
{
return channel % 2;
}
static int pwm_rpi_get_cycles_per_sec(const struct device *dev, uint32_t ch, uint64_t *cycles)
{
float f_clock_in;
int slice = pwm_rpi_channel_to_slice(ch);
if (ch >= PWM_RPI_NUM_CHANNELS) {
return -EINVAL;
}
f_clock_in = (float)sys_clock_hw_cycles_per_sec();
/* No need to check for divide by 0 since the minimum value of
* pwm_rpi_get_clkdiv is 1
*/
*cycles = (uint64_t)(f_clock_in / pwm_rpi_get_clkdiv(dev, slice));
return 0;
}
/* The pico_sdk only allows setting the polarity of both channels at once.
* This is a convenience function to make setting the polarity of a single
* channel easier.
*/
static void pwm_rpi_set_channel_polarity(const struct device *dev, int slice,
int pico_channel, bool inverted)
{
const struct pwm_rpi_config *cfg = dev->config;
bool pwm_polarity_a = (cfg->pwm_controller->slice[slice].csr & PWM_CH0_CSR_A_INV_BITS) > 0;
bool pwm_polarity_b = (cfg->pwm_controller->slice[slice].csr & PWM_CH0_CSR_B_INV_BITS) > 0;
if (pico_channel == PWM_CHAN_A) {
pwm_polarity_a = inverted;
} else if (pico_channel == PWM_CHAN_B) {
pwm_polarity_b = inverted;
}
pwm_set_output_polarity(slice, pwm_polarity_a, pwm_polarity_b);
}
static int pwm_rpi_set_cycles(const struct device *dev, uint32_t ch, uint32_t period_cycles,
uint32_t pulse_cycles, pwm_flags_t flags)
{
if (ch >= PWM_RPI_NUM_CHANNELS) {
return -EINVAL;
}
if (period_cycles > PWM_RPI_PICO_COUNTER_TOP_MAX ||
pulse_cycles > PWM_RPI_PICO_COUNTER_TOP_MAX) {
return -EINVAL;
}
int slice = pwm_rpi_channel_to_slice(ch);
/* this is the channel within a pwm slice */
int pico_channel = pwm_rpi_channel_to_pico_channel(ch);
pwm_rpi_set_channel_polarity(dev, slice, pico_channel,
(flags & PWM_POLARITY_MASK) == PWM_POLARITY_INVERTED);
pwm_set_wrap(slice, period_cycles);
pwm_set_chan_level(slice, ch, pulse_cycles);
return 0;
};
struct pwm_driver_api pwm_rpi_driver_api = {
.get_cycles_per_sec = pwm_rpi_get_cycles_per_sec,
.set_cycles = pwm_rpi_set_cycles,
};
static int pwm_rpi_init(const struct device *dev)
{
const struct pwm_rpi_config *cfg = dev->config;
pwm_config slice_cfg;
size_t slice_idx;
int err;
err = pinctrl_apply_state(cfg->pcfg, PINCTRL_STATE_DEFAULT);
if (err) {
LOG_ERR("Failed to configure pins for PWM. err=%d", err);
return err;
}
for (slice_idx = 0; slice_idx < NUM_PWM_SLICES; slice_idx++) {
slice_cfg = pwm_get_default_config();
pwm_config_set_clkdiv_mode(&slice_cfg, PWM_DIV_FREE_RUNNING);
pwm_init(slice_idx, &slice_cfg, false);
pwm_set_clkdiv_int_frac(slice_idx,
cfg->slice_configs[slice_idx].integral,
cfg->slice_configs[slice_idx].frac);
pwm_set_enabled(slice_idx, true);
}
return 0;
}
#define PWM_INST_RPI_SLICE_DIVIDER(idx, n) \
{ \
.integral = DT_INST_PROP(idx, UTIL_CAT(divider_int_, n)), \
.frac = DT_INST_PROP(idx, UTIL_CAT(divider_frac_, n)), \
}
#define PWM_RPI_INIT(idx) \
\
PINCTRL_DT_INST_DEFINE(idx); \
static const struct pwm_rpi_config pwm_rpi_config_##idx = { \
.pwm_controller = (pwm_hw_t *)DT_INST_REG_ADDR(idx), \
.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(idx), \
.slice_configs = { \
PWM_INST_RPI_SLICE_DIVIDER(idx, 0), \
PWM_INST_RPI_SLICE_DIVIDER(idx, 1), \
PWM_INST_RPI_SLICE_DIVIDER(idx, 2), \
PWM_INST_RPI_SLICE_DIVIDER(idx, 3), \
PWM_INST_RPI_SLICE_DIVIDER(idx, 4), \
PWM_INST_RPI_SLICE_DIVIDER(idx, 5), \
PWM_INST_RPI_SLICE_DIVIDER(idx, 6), \
PWM_INST_RPI_SLICE_DIVIDER(idx, 7), \
}, \
.reset = RESET_DT_SPEC_INST_GET(idx), \
}; \
\
DEVICE_DT_INST_DEFINE(idx, pwm_rpi_init, NULL, NULL, &pwm_rpi_config_##idx, POST_KERNEL, \
CONFIG_KERNEL_INIT_PRIORITY_DEVICE, &pwm_rpi_driver_api);
DT_INST_FOREACH_STATUS_OKAY(PWM_RPI_INIT);

View file

@ -151,7 +151,7 @@
clocks = <&system_clk>;
interrupts = <4 RPI_PICO_DEFAULT_IRQ_PRIORITY>;
interrupt-names = "PWM_IRQ_WRAP";
label = "PWM_CTRL_0";
label = "PWM_0";
status = "disabled";
#pwm-cells = <3>;
};

View file

@ -93,6 +93,9 @@ if(CONFIG_HAS_RPI_PICO)
zephyr_include_directories_ifdef(CONFIG_PICOSDK_USE_FLASH
${rp2_common_dir}/hardware_flash/include)
zephyr_include_directories_ifdef(CONFIG_PICOSDK_USE_PWM
${rp2_common_dir}/hardware_pwm/include)
# Some flash driver functions must be executed from the RAM.
# Originally pico-sdk places them in the RW data section, so this
# implementation does the same.
@ -104,4 +107,5 @@ if(CONFIG_HAS_RPI_PICO)
PROPERTIES
COMPILE_FLAGS $<TARGET_PROPERTY:compiler,warning_no_pointer_arithmetic>
)
endif()

View file

@ -18,3 +18,8 @@ config PICOSDK_USE_FLASH
bool
help
Use the flash driver from pico-sdk
config PICOSDK_USE_PWM
bool
help
Use the PWM driver from pico-sdk

View file

@ -41,7 +41,7 @@ static int rp2040_init(const struct device *arg)
~(RESETS_RESET_ADC_BITS | RESETS_RESET_RTC_BITS |
RESETS_RESET_SPI0_BITS | RESETS_RESET_SPI1_BITS |
RESETS_RESET_UART0_BITS | RESETS_RESET_UART1_BITS |
RESETS_RESET_USBCTRL_BITS));
RESETS_RESET_USBCTRL_BITS | RESETS_RESET_PWM_BITS));
clocks_init();