diff options
Diffstat (limited to 'chip/stm32/pwm.c')
| -rw-r--r-- | chip/stm32/pwm.c | 164 |
1 files changed, 0 insertions, 164 deletions
diff --git a/chip/stm32/pwm.c b/chip/stm32/pwm.c deleted file mode 100644 index 0b339399c9..0000000000 --- a/chip/stm32/pwm.c +++ /dev/null @@ -1,164 +0,0 @@ -/* Copyright 2013 The Chromium OS Authors. All rights reserved. - * Use of this source code is governed by a BSD-style license that can be - * found in the LICENSE file. - */ - -/* PWM control module for STM32 */ - -#include "clock.h" -#include "clock-f.h" -#include "gpio.h" -#include "hooks.h" -#include "hwtimer.h" -#include "pwm.h" -#include "pwm_chip.h" -#include "registers.h" -#include "system.h" -#include "util.h" - -/* Bitmap of currently active PWM channels. 1 bit per channel. */ -static uint32_t using_pwm; - -void pwm_set_duty(enum pwm_channel ch, int percent) -{ - const struct pwm_t *pwm = pwm_channels + ch; - timer_ctlr_t *tim = (timer_ctlr_t *)(pwm->tim.base); - - ASSERT((percent >= 0) && (percent <= 100)); - tim->ccr[pwm->channel] = percent; -} - -int pwm_get_duty(enum pwm_channel ch) -{ - const struct pwm_t *pwm = pwm_channels + ch; - timer_ctlr_t *tim = (timer_ctlr_t *)(pwm->tim.base); - return tim->ccr[pwm->channel]; -} - -static void pwm_configure(enum pwm_channel ch) -{ - const struct pwm_t *pwm = pwm_channels + ch; - timer_ctlr_t *tim = (timer_ctlr_t *)(pwm->tim.base); - volatile unsigned *ccmr = NULL; - /* Default frequency = 100 Hz */ - int frequency = pwm->frequency ? pwm->frequency : 100; - uint16_t ccer; - - if (using_pwm & BIT(ch)) - return; - - /* Enable timer */ - __hw_timer_enable_clock(pwm->tim.id, 1); - - /* Disable counter during setup */ - tim->cr1 = 0x0000; - - /* - * Timer clock / PSC determines how fast the counter operates. - * ARR determines the wave period, CCRn determines duty cycle. - * Thus, frequency = timer_freq / PSC / ARR. so: - * - * frequency = timer_freq / (timer_freq/10000 + 1) / (99 + 1) = 100 Hz. - */ - tim->psc = clock_get_timer_freq() / (frequency * 100) - 1; - tim->arr = 99; - - if (pwm->channel <= 2) /* Channel ID starts from 1 */ - ccmr = &tim->ccmr1; - else - ccmr = &tim->ccmr2; - - /* Output, PWM mode 1, preload enable */ - if (pwm->channel & 0x1) - *ccmr = (6 << 4) | BIT(3); - else - *ccmr = (6 << 12) | BIT(11); - - /* Output enable. Set active high/low. */ - if (pwm->flags & PWM_CONFIG_ACTIVE_LOW) - ccer = 3 << (pwm->channel * 4 - 4); - else - ccer = 1 << (pwm->channel * 4 - 4); - - /* Enable complementary output, if present. */ - if (pwm->flags & PWM_CONFIG_COMPLEMENTARY_OUTPUT) - ccer |= (ccer << 2); - - tim->ccer = ccer; - - /* - * Main output enable. - * TODO(shawnn): BDTR is undocumented on STM32L. Verify this isn't - * harmful on STM32L. - */ - tim->bdtr |= BIT(15); - - /* Generate update event to force loading of shadow registers */ - tim->egr |= 1; - - /* Enable auto-reload preload, start counting */ - tim->cr1 |= BIT(7) | BIT(0); - - atomic_or(&using_pwm, 1 << ch); - - /* Prevent sleep */ - disable_sleep(SLEEP_MASK_PWM); -} - -static void pwm_disable(enum pwm_channel ch) -{ - const struct pwm_t *pwm = pwm_channels + ch; - timer_ctlr_t *tim = (timer_ctlr_t *)(pwm->tim.base); - - if ((using_pwm & BIT(ch)) == 0) - return; - - /* Main output disable */ - tim->bdtr &= ~BIT(15); - - /* Disable counter */ - tim->cr1 &= ~0x1; - - /* Disable timer clock */ - __hw_timer_enable_clock(pwm->tim.id, 0); - - /* Allow sleep */ - enable_sleep(SLEEP_MASK_PWM); - - atomic_clear_bits(&using_pwm, 1 << ch); - - /* Unless another PWM is active... Then prevent sleep */ - if (using_pwm) - disable_sleep(SLEEP_MASK_PWM); -} - -void pwm_enable(enum pwm_channel ch, int enabled) -{ - if (enabled) - pwm_configure(ch); - else - pwm_disable(ch); -} - -int pwm_get_enabled(enum pwm_channel ch) -{ - return using_pwm & BIT(ch); -} - -static void pwm_reconfigure(enum pwm_channel ch) -{ - atomic_clear_bits(&using_pwm, 1 << ch); - pwm_configure(ch); -} - -/** - * Handle clock frequency change - */ -static void pwm_freq_change(void) -{ - int i; - for (i = 0; i < PWM_CH_COUNT; ++i) - if (pwm_get_enabled(i)) - pwm_reconfigure(i); -} -DECLARE_HOOK(HOOK_FREQ_CHANGE, pwm_freq_change, HOOK_PRIO_DEFAULT); |