added prescaler for 16 bit pwm in LPC1347 target
Fork of mbed-dev by
targets/hal/TARGET_Freescale/TARGET_KSDK2_MCUS/TARGET_KL43Z/pwmout_api.c@147:ba84b7dc41a7, 2016-09-10 (annotated)
- Committer:
- JojoS
- Date:
- Sat Sep 10 15:32:04 2016 +0000
- Revision:
- 147:ba84b7dc41a7
- Parent:
- 144:ef7eb2e8f9f7
added prescaler for 16 bit timers (solution as in LPC11xx), default prescaler 31 for max 28 ms period time
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
<> | 144:ef7eb2e8f9f7 | 1 | /* mbed Microcontroller Library |
<> | 144:ef7eb2e8f9f7 | 2 | * Copyright (c) 2006-2013 ARM Limited |
<> | 144:ef7eb2e8f9f7 | 3 | * |
<> | 144:ef7eb2e8f9f7 | 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
<> | 144:ef7eb2e8f9f7 | 5 | * you may not use this file except in compliance with the License. |
<> | 144:ef7eb2e8f9f7 | 6 | * You may obtain a copy of the License at |
<> | 144:ef7eb2e8f9f7 | 7 | * |
<> | 144:ef7eb2e8f9f7 | 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
<> | 144:ef7eb2e8f9f7 | 9 | * |
<> | 144:ef7eb2e8f9f7 | 10 | * Unless required by applicable law or agreed to in writing, software |
<> | 144:ef7eb2e8f9f7 | 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
<> | 144:ef7eb2e8f9f7 | 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
<> | 144:ef7eb2e8f9f7 | 13 | * See the License for the specific language governing permissions and |
<> | 144:ef7eb2e8f9f7 | 14 | * limitations under the License. |
<> | 144:ef7eb2e8f9f7 | 15 | */ |
<> | 144:ef7eb2e8f9f7 | 16 | #include "mbed_assert.h" |
<> | 144:ef7eb2e8f9f7 | 17 | #include "pwmout_api.h" |
<> | 144:ef7eb2e8f9f7 | 18 | |
<> | 144:ef7eb2e8f9f7 | 19 | #if DEVICE_PWMOUT |
<> | 144:ef7eb2e8f9f7 | 20 | |
<> | 144:ef7eb2e8f9f7 | 21 | #include "cmsis.h" |
<> | 144:ef7eb2e8f9f7 | 22 | #include "pinmap.h" |
<> | 144:ef7eb2e8f9f7 | 23 | #include "fsl_tpm.h" |
<> | 144:ef7eb2e8f9f7 | 24 | #include "PeripheralPins.h" |
<> | 144:ef7eb2e8f9f7 | 25 | |
<> | 144:ef7eb2e8f9f7 | 26 | static float pwm_clock_mhz; |
<> | 144:ef7eb2e8f9f7 | 27 | /* Array of TPM peripheral base address. */ |
<> | 144:ef7eb2e8f9f7 | 28 | static TPM_Type *const tpm_addrs[] = TPM_BASE_PTRS; |
<> | 144:ef7eb2e8f9f7 | 29 | |
<> | 144:ef7eb2e8f9f7 | 30 | void pwmout_init(pwmout_t* obj, PinName pin) { |
<> | 144:ef7eb2e8f9f7 | 31 | PWMName pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM); |
<> | 144:ef7eb2e8f9f7 | 32 | MBED_ASSERT(pwm != (PWMName)NC); |
<> | 144:ef7eb2e8f9f7 | 33 | |
<> | 144:ef7eb2e8f9f7 | 34 | obj->pwm_name = pwm; |
<> | 144:ef7eb2e8f9f7 | 35 | |
<> | 144:ef7eb2e8f9f7 | 36 | uint32_t pwm_base_clock; |
<> | 144:ef7eb2e8f9f7 | 37 | |
<> | 144:ef7eb2e8f9f7 | 38 | /* Set the TPM clock source to be IRC 48M */ |
<> | 144:ef7eb2e8f9f7 | 39 | CLOCK_SetTpmClock(1U); |
<> | 144:ef7eb2e8f9f7 | 40 | pwm_base_clock = CLOCK_GetFreq(kCLOCK_McgIrc48MClk); |
<> | 144:ef7eb2e8f9f7 | 41 | float clkval = (float)pwm_base_clock / 1000000.0f; |
<> | 144:ef7eb2e8f9f7 | 42 | uint32_t clkdiv = 0; |
<> | 144:ef7eb2e8f9f7 | 43 | while (clkval > 1) { |
<> | 144:ef7eb2e8f9f7 | 44 | clkdiv++; |
<> | 144:ef7eb2e8f9f7 | 45 | clkval /= 2.0f; |
<> | 144:ef7eb2e8f9f7 | 46 | if (clkdiv == 7) { |
<> | 144:ef7eb2e8f9f7 | 47 | break; |
<> | 144:ef7eb2e8f9f7 | 48 | } |
<> | 144:ef7eb2e8f9f7 | 49 | } |
<> | 144:ef7eb2e8f9f7 | 50 | |
<> | 144:ef7eb2e8f9f7 | 51 | pwm_clock_mhz = clkval; |
<> | 144:ef7eb2e8f9f7 | 52 | uint32_t channel = pwm & 0xF; |
<> | 144:ef7eb2e8f9f7 | 53 | uint32_t instance = pwm >> TPM_SHIFT; |
<> | 144:ef7eb2e8f9f7 | 54 | tpm_config_t tpmInfo; |
<> | 144:ef7eb2e8f9f7 | 55 | |
<> | 144:ef7eb2e8f9f7 | 56 | TPM_GetDefaultConfig(&tpmInfo); |
<> | 144:ef7eb2e8f9f7 | 57 | tpmInfo.prescale = (tpm_clock_prescale_t)clkdiv; |
<> | 144:ef7eb2e8f9f7 | 58 | /* Initialize TPM module */ |
<> | 144:ef7eb2e8f9f7 | 59 | TPM_Init(tpm_addrs[instance], &tpmInfo); |
<> | 144:ef7eb2e8f9f7 | 60 | |
<> | 144:ef7eb2e8f9f7 | 61 | tpm_chnl_pwm_signal_param_t config = { |
<> | 144:ef7eb2e8f9f7 | 62 | .chnlNumber = (tpm_chnl_t)channel, |
<> | 144:ef7eb2e8f9f7 | 63 | .level = kTPM_HighTrue, |
<> | 144:ef7eb2e8f9f7 | 64 | .dutyCyclePercent = 0, |
<> | 144:ef7eb2e8f9f7 | 65 | }; |
<> | 144:ef7eb2e8f9f7 | 66 | // default to 20ms: standard for servos, and fine for e.g. brightness control |
<> | 144:ef7eb2e8f9f7 | 67 | TPM_SetupPwm(tpm_addrs[instance], &config, 1, kTPM_EdgeAlignedPwm, 50, pwm_base_clock); |
<> | 144:ef7eb2e8f9f7 | 68 | |
<> | 144:ef7eb2e8f9f7 | 69 | TPM_StartTimer(tpm_addrs[instance], kTPM_SystemClock); |
<> | 144:ef7eb2e8f9f7 | 70 | |
<> | 144:ef7eb2e8f9f7 | 71 | // Wire pinout |
<> | 144:ef7eb2e8f9f7 | 72 | pinmap_pinout(pin, PinMap_PWM); |
<> | 144:ef7eb2e8f9f7 | 73 | } |
<> | 144:ef7eb2e8f9f7 | 74 | |
<> | 144:ef7eb2e8f9f7 | 75 | void pwmout_free(pwmout_t* obj) { |
<> | 144:ef7eb2e8f9f7 | 76 | TPM_Deinit(tpm_addrs[obj->pwm_name >> TPM_SHIFT]); |
<> | 144:ef7eb2e8f9f7 | 77 | } |
<> | 144:ef7eb2e8f9f7 | 78 | |
<> | 144:ef7eb2e8f9f7 | 79 | void pwmout_write(pwmout_t* obj, float value) { |
<> | 144:ef7eb2e8f9f7 | 80 | if (value < 0.0f) { |
<> | 144:ef7eb2e8f9f7 | 81 | value = 0.0f; |
<> | 144:ef7eb2e8f9f7 | 82 | } else if (value > 1.0f) { |
<> | 144:ef7eb2e8f9f7 | 83 | value = 1.0f; |
<> | 144:ef7eb2e8f9f7 | 84 | } |
<> | 144:ef7eb2e8f9f7 | 85 | |
<> | 144:ef7eb2e8f9f7 | 86 | TPM_Type *base = tpm_addrs[obj->pwm_name >> TPM_SHIFT]; |
<> | 144:ef7eb2e8f9f7 | 87 | uint16_t mod = base->MOD & TPM_MOD_MOD_MASK; |
<> | 144:ef7eb2e8f9f7 | 88 | uint32_t new_count = (uint32_t)((float)(mod) * value); |
<> | 144:ef7eb2e8f9f7 | 89 | // Update of CnV register |
<> | 144:ef7eb2e8f9f7 | 90 | base->CONTROLS[obj->pwm_name & 0xF].CnV = new_count; |
<> | 144:ef7eb2e8f9f7 | 91 | base->CNT = 0; |
<> | 144:ef7eb2e8f9f7 | 92 | } |
<> | 144:ef7eb2e8f9f7 | 93 | |
<> | 144:ef7eb2e8f9f7 | 94 | float pwmout_read(pwmout_t* obj) { |
<> | 144:ef7eb2e8f9f7 | 95 | TPM_Type *base = tpm_addrs[obj->pwm_name >> TPM_SHIFT]; |
<> | 144:ef7eb2e8f9f7 | 96 | uint16_t count = (base->CONTROLS[obj->pwm_name & 0xF].CnV) & TPM_CnV_VAL_MASK; |
<> | 144:ef7eb2e8f9f7 | 97 | uint16_t mod = base->MOD & TPM_MOD_MOD_MASK; |
<> | 144:ef7eb2e8f9f7 | 98 | |
<> | 144:ef7eb2e8f9f7 | 99 | if (mod == 0) |
<> | 144:ef7eb2e8f9f7 | 100 | return 0.0; |
<> | 144:ef7eb2e8f9f7 | 101 | float v = (float)(count) / (float)(mod); |
<> | 144:ef7eb2e8f9f7 | 102 | return (v > 1.0f) ? (1.0f) : (v); |
<> | 144:ef7eb2e8f9f7 | 103 | } |
<> | 144:ef7eb2e8f9f7 | 104 | |
<> | 144:ef7eb2e8f9f7 | 105 | void pwmout_period(pwmout_t* obj, float seconds) { |
<> | 144:ef7eb2e8f9f7 | 106 | pwmout_period_us(obj, seconds * 1000000.0f); |
<> | 144:ef7eb2e8f9f7 | 107 | } |
<> | 144:ef7eb2e8f9f7 | 108 | |
<> | 144:ef7eb2e8f9f7 | 109 | void pwmout_period_ms(pwmout_t* obj, int ms) { |
<> | 144:ef7eb2e8f9f7 | 110 | pwmout_period_us(obj, ms * 1000); |
<> | 144:ef7eb2e8f9f7 | 111 | } |
<> | 144:ef7eb2e8f9f7 | 112 | |
<> | 144:ef7eb2e8f9f7 | 113 | // Set the PWM period, keeping the duty cycle the same. |
<> | 144:ef7eb2e8f9f7 | 114 | void pwmout_period_us(pwmout_t* obj, int us) { |
<> | 144:ef7eb2e8f9f7 | 115 | TPM_Type *base = tpm_addrs[obj->pwm_name >> TPM_SHIFT]; |
<> | 144:ef7eb2e8f9f7 | 116 | float dc = pwmout_read(obj); |
<> | 144:ef7eb2e8f9f7 | 117 | |
<> | 144:ef7eb2e8f9f7 | 118 | // Stop TPM clock to ensure instant update of MOD register |
<> | 144:ef7eb2e8f9f7 | 119 | base->MOD = TPM_MOD_MOD((pwm_clock_mhz * (float)us) - 1); |
<> | 144:ef7eb2e8f9f7 | 120 | pwmout_write(obj, dc); |
<> | 144:ef7eb2e8f9f7 | 121 | } |
<> | 144:ef7eb2e8f9f7 | 122 | |
<> | 144:ef7eb2e8f9f7 | 123 | void pwmout_pulsewidth(pwmout_t* obj, float seconds) { |
<> | 144:ef7eb2e8f9f7 | 124 | pwmout_pulsewidth_us(obj, seconds * 1000000.0f); |
<> | 144:ef7eb2e8f9f7 | 125 | } |
<> | 144:ef7eb2e8f9f7 | 126 | |
<> | 144:ef7eb2e8f9f7 | 127 | void pwmout_pulsewidth_ms(pwmout_t* obj, int ms) { |
<> | 144:ef7eb2e8f9f7 | 128 | pwmout_pulsewidth_us(obj, ms * 1000); |
<> | 144:ef7eb2e8f9f7 | 129 | } |
<> | 144:ef7eb2e8f9f7 | 130 | |
<> | 144:ef7eb2e8f9f7 | 131 | void pwmout_pulsewidth_us(pwmout_t* obj, int us) { |
<> | 144:ef7eb2e8f9f7 | 132 | TPM_Type *base = tpm_addrs[obj->pwm_name >> TPM_SHIFT]; |
<> | 144:ef7eb2e8f9f7 | 133 | uint32_t value = (uint32_t)(pwm_clock_mhz * (float)us); |
<> | 144:ef7eb2e8f9f7 | 134 | |
<> | 144:ef7eb2e8f9f7 | 135 | // Update of CnV register |
<> | 144:ef7eb2e8f9f7 | 136 | base->CONTROLS[obj->pwm_name & 0xF].CnV = value; |
<> | 144:ef7eb2e8f9f7 | 137 | } |
<> | 144:ef7eb2e8f9f7 | 138 | |
<> | 144:ef7eb2e8f9f7 | 139 | #endif |