david dicarlo / mbed-src-FLL48

mbed library sources: Modified to operate FRDM-KL25Z at 48MHz from internal 32kHz oscillator (nothing else changed).

Fork of mbed-src by mbed official

The only file that changed is: mbed-src-FLL48/targets/cmsis/TARGET_Freescale/TARGET_KL25Z/system_MKL25Z4.h

targets/hal/TARGET_NXP/TARGET_LPC11CXX/pwmout_api.c@20:4263a77256ae, 2013-09-10 (annotated)

Committer:
bogdanm
Date:
Tue Sep 10 15:14:19 2013 +0300
Revision:
20:4263a77256ae
Sync with git revision 171dda705c947bf910926a0b73d6a4797802554d

Who changed what in which revision?

UserRevisionLine numberNew contents of line
bogdanm 20:4263a77256ae 1 /* mbed Microcontroller Library
bogdanm 20:4263a77256ae 2 * Copyright (c) 2006-2013 ARM Limited
bogdanm 20:4263a77256ae 3 *
bogdanm 20:4263a77256ae 4 * Licensed under the Apache License, Version 2.0 (the "License");
bogdanm 20:4263a77256ae 5 * you may not use this file except in compliance with the License.
bogdanm 20:4263a77256ae 6 * You may obtain a copy of the License at
bogdanm 20:4263a77256ae 7 *
bogdanm 20:4263a77256ae 8 * http://www.apache.org/licenses/LICENSE-2.0
bogdanm 20:4263a77256ae 9 *
bogdanm 20:4263a77256ae 10 * Unless required by applicable law or agreed to in writing, software
bogdanm 20:4263a77256ae 11 * distributed under the License is distributed on an "AS IS" BASIS,
bogdanm 20:4263a77256ae 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
bogdanm 20:4263a77256ae 13 * See the License for the specific language governing permissions and
bogdanm 20:4263a77256ae 14 * limitations under the License.
bogdanm 20:4263a77256ae 15 */
bogdanm 20:4263a77256ae 16 #include "pwmout_api.h"
bogdanm 20:4263a77256ae 17 #include "cmsis.h"
bogdanm 20:4263a77256ae 18 #include "pinmap.h"
bogdanm 20:4263a77256ae 19 #include "error.h"
bogdanm 20:4263a77256ae 20
bogdanm 20:4263a77256ae 21 #define TCR_CNT_EN 0x00000001
bogdanm 20:4263a77256ae 22 #define TCR_RESET 0x00000002
bogdanm 20:4263a77256ae 23
bogdanm 20:4263a77256ae 24 /* To have a PWM where we can change both the period and the duty cycle,
bogdanm 20:4263a77256ae 25 * we need an entire timer. With the following conventions:
bogdanm 20:4263a77256ae 26 * * MR3 is used for the PWM period
bogdanm 20:4263a77256ae 27 * * MR0, MR1, MR2 are used for the duty cycle
bogdanm 20:4263a77256ae 28 */
bogdanm 20:4263a77256ae 29 static const PinMap PinMap_PWM[] = {
bogdanm 20:4263a77256ae 30 /* CT16B0 */
bogdanm 20:4263a77256ae 31 {P0_8 , PWM_1, 0x02}, /* MR0 */
bogdanm 20:4263a77256ae 32 {P0_9 , PWM_2, 0x02}, /* MR1 */
bogdanm 20:4263a77256ae 33 {P0_10, PWM_3, 0x03}, /* MR2 */
bogdanm 20:4263a77256ae 34
bogdanm 20:4263a77256ae 35 /* CT16B1 */
bogdanm 20:4263a77256ae 36 {P1_9 , PWM_4, 0x01}, /* MR0 */
bogdanm 20:4263a77256ae 37 {P1_10, PWM_5, 0x02}, /* MR1 */
bogdanm 20:4263a77256ae 38
bogdanm 20:4263a77256ae 39 /* CT32B0 */
bogdanm 20:4263a77256ae 40 {P1_6 , PWM_6, 0x02}, /* MR0 */
bogdanm 20:4263a77256ae 41 {P1_7 , PWM_7, 0x02}, /* MR1 */
bogdanm 20:4263a77256ae 42 {P0_1 , PWM_8, 0x02}, /* MR2 */
bogdanm 20:4263a77256ae 43
bogdanm 20:4263a77256ae 44 /* CT32B1 */
bogdanm 20:4263a77256ae 45 {P1_1 , PWM_9 ,0x03}, /* MR0 */
bogdanm 20:4263a77256ae 46 {P1_2 , PWM_10,0x03}, /* MR1 */
bogdanm 20:4263a77256ae 47 {P1_3 , PWM_11,0x03}, /* MR2 */
bogdanm 20:4263a77256ae 48
bogdanm 20:4263a77256ae 49 {NC , NC ,0x00}
bogdanm 20:4263a77256ae 50 };
bogdanm 20:4263a77256ae 51
bogdanm 20:4263a77256ae 52 typedef struct {
bogdanm 20:4263a77256ae 53 uint8_t timer;
bogdanm 20:4263a77256ae 54 uint8_t mr;
bogdanm 20:4263a77256ae 55 } timer_mr;
bogdanm 20:4263a77256ae 56
bogdanm 20:4263a77256ae 57 static timer_mr pwm_timer_map[11] = {
bogdanm 20:4263a77256ae 58 {0, 0}, /* CT16B0, MR0 */
bogdanm 20:4263a77256ae 59 {0, 1}, /* CT16B0, MR1 */
bogdanm 20:4263a77256ae 60 {0, 2}, /* CT16B0, MR2 */
bogdanm 20:4263a77256ae 61
bogdanm 20:4263a77256ae 62 {1, 0}, /* CT16B1, MR0 */
bogdanm 20:4263a77256ae 63 {1, 1}, /* CT16B1, MR1 */
bogdanm 20:4263a77256ae 64
bogdanm 20:4263a77256ae 65 {2, 0}, /* CT32B0, MR0 */
bogdanm 20:4263a77256ae 66 {2, 1}, /* CT32B0, MR1 */
bogdanm 20:4263a77256ae 67 {2, 2}, /* CT32B0, MR2 */
bogdanm 20:4263a77256ae 68
bogdanm 20:4263a77256ae 69 {3, 0}, /* CT32B1, MR0 */
bogdanm 20:4263a77256ae 70 {3, 1}, /* CT32B1, MR1 */
bogdanm 20:4263a77256ae 71 {3, 2} /* CT32B1, MR2 */
bogdanm 20:4263a77256ae 72 };
bogdanm 20:4263a77256ae 73
bogdanm 20:4263a77256ae 74 static LPC_TMR_TypeDef *Timers[4] = {
bogdanm 20:4263a77256ae 75 LPC_TMR16B0, LPC_TMR16B1,
bogdanm 20:4263a77256ae 76 LPC_TMR32B0, LPC_TMR32B1
bogdanm 20:4263a77256ae 77 };
bogdanm 20:4263a77256ae 78
bogdanm 20:4263a77256ae 79 static unsigned int pwm_clock_mhz;
bogdanm 20:4263a77256ae 80
bogdanm 20:4263a77256ae 81 void pwmout_init(pwmout_t* obj, PinName pin) {
bogdanm 20:4263a77256ae 82 // determine the channel
bogdanm 20:4263a77256ae 83 PWMName pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM);
bogdanm 20:4263a77256ae 84 if (pwm == (uint32_t)NC)
bogdanm 20:4263a77256ae 85 error("PwmOut pin mapping failed");
bogdanm 20:4263a77256ae 86
bogdanm 20:4263a77256ae 87 obj->pwm = pwm;
bogdanm 20:4263a77256ae 88
bogdanm 20:4263a77256ae 89 // Timer registers
bogdanm 20:4263a77256ae 90 timer_mr tid = pwm_timer_map[pwm];
bogdanm 20:4263a77256ae 91 LPC_TMR_TypeDef *timer = Timers[tid.timer];
bogdanm 20:4263a77256ae 92
bogdanm 20:4263a77256ae 93 // Disable timer
bogdanm 20:4263a77256ae 94 timer->TCR = 0;
bogdanm 20:4263a77256ae 95
bogdanm 20:4263a77256ae 96 // Power the correspondent timer
bogdanm 20:4263a77256ae 97 LPC_SYSCON->SYSAHBCLKCTRL |= 1 << (tid.timer + 7);
bogdanm 20:4263a77256ae 98
bogdanm 20:4263a77256ae 99 /* Enable PWM function */
bogdanm 20:4263a77256ae 100 timer->PWMC = (1 << 3)|(1 << 2)|(1 << 1)|(1 << 0);
bogdanm 20:4263a77256ae 101
bogdanm 20:4263a77256ae 102 /* Reset Functionality on MR3 controlling the PWM period */
bogdanm 20:4263a77256ae 103 timer->MCR = 1 << 10;
bogdanm 20:4263a77256ae 104
bogdanm 20:4263a77256ae 105 pwm_clock_mhz = SystemCoreClock / 1000000;
bogdanm 20:4263a77256ae 106
bogdanm 20:4263a77256ae 107 // default to 20ms: standard for servos, and fine for e.g. brightness control
bogdanm 20:4263a77256ae 108 pwmout_period_ms(obj, 20);
bogdanm 20:4263a77256ae 109 pwmout_write (obj, 0);
bogdanm 20:4263a77256ae 110
bogdanm 20:4263a77256ae 111 // Wire pinout
bogdanm 20:4263a77256ae 112 pinmap_pinout(pin, PinMap_PWM);
bogdanm 20:4263a77256ae 113 }
bogdanm 20:4263a77256ae 114
bogdanm 20:4263a77256ae 115 void pwmout_free(pwmout_t* obj) {
bogdanm 20:4263a77256ae 116 // [TODO]
bogdanm 20:4263a77256ae 117 }
bogdanm 20:4263a77256ae 118
bogdanm 20:4263a77256ae 119 void pwmout_write(pwmout_t* obj, float value) {
bogdanm 20:4263a77256ae 120 if (value < 0.0f) {
bogdanm 20:4263a77256ae 121 value = 0.0;
bogdanm 20:4263a77256ae 122 } else if (value > 1.0f) {
bogdanm 20:4263a77256ae 123 value = 1.0;
bogdanm 20:4263a77256ae 124 }
bogdanm 20:4263a77256ae 125
bogdanm 20:4263a77256ae 126 timer_mr tid = pwm_timer_map[obj->pwm];
bogdanm 20:4263a77256ae 127 LPC_TMR_TypeDef *timer = Timers[tid.timer];
bogdanm 20:4263a77256ae 128 uint32_t t_off = timer->MR3 - (uint32_t)((float)(timer->MR3) * value);
bogdanm 20:4263a77256ae 129
bogdanm 20:4263a77256ae 130 timer->TCR = TCR_RESET;
bogdanm 20:4263a77256ae 131 timer->MR[tid.mr] = t_off;
bogdanm 20:4263a77256ae 132 timer->TCR = TCR_CNT_EN;
bogdanm 20:4263a77256ae 133 }
bogdanm 20:4263a77256ae 134
bogdanm 20:4263a77256ae 135 float pwmout_read(pwmout_t* obj) {
bogdanm 20:4263a77256ae 136 timer_mr tid = pwm_timer_map[obj->pwm];
bogdanm 20:4263a77256ae 137 LPC_TMR_TypeDef *timer = Timers[tid.timer];
bogdanm 20:4263a77256ae 138
bogdanm 20:4263a77256ae 139 float v = (float)(timer->MR3 - timer->MR[tid.mr]) / (float)(timer->MR3);
bogdanm 20:4263a77256ae 140 return (v > 1.0f) ? (1.0f) : (v);
bogdanm 20:4263a77256ae 141 }
bogdanm 20:4263a77256ae 142
bogdanm 20:4263a77256ae 143 void pwmout_period(pwmout_t* obj, float seconds) {
bogdanm 20:4263a77256ae 144 pwmout_period_us(obj, seconds * 1000000.0f);
bogdanm 20:4263a77256ae 145 }
bogdanm 20:4263a77256ae 146
bogdanm 20:4263a77256ae 147 void pwmout_period_ms(pwmout_t* obj, int ms) {
bogdanm 20:4263a77256ae 148 pwmout_period_us(obj, ms * 1000);
bogdanm 20:4263a77256ae 149 }
bogdanm 20:4263a77256ae 150
bogdanm 20:4263a77256ae 151 // Set the PWM period, keeping the duty cycle the same.
bogdanm 20:4263a77256ae 152 void pwmout_period_us(pwmout_t* obj, int us) {
bogdanm 20:4263a77256ae 153 int i = 0;
bogdanm 20:4263a77256ae 154 uint32_t period_ticks = pwm_clock_mhz * us;
bogdanm 20:4263a77256ae 155
bogdanm 20:4263a77256ae 156 timer_mr tid = pwm_timer_map[obj->pwm];
bogdanm 20:4263a77256ae 157 LPC_TMR_TypeDef *timer = Timers[tid.timer];
bogdanm 20:4263a77256ae 158 uint32_t old_period_ticks = timer->MR3;
bogdanm 20:4263a77256ae 159
bogdanm 20:4263a77256ae 160 timer->TCR = TCR_RESET;
bogdanm 20:4263a77256ae 161 timer->MR3 = period_ticks;
bogdanm 20:4263a77256ae 162
bogdanm 20:4263a77256ae 163 // Scale the pulse width to preserve the duty ratio
bogdanm 20:4263a77256ae 164 if (old_period_ticks > 0) {
bogdanm 20:4263a77256ae 165 for (i=0; i<3; i++) {
bogdanm 20:4263a77256ae 166 uint32_t t_off = period_ticks - (uint32_t)(((uint64_t)timer->MR[i] * (uint64_t)period_ticks) / (uint64_t)old_period_ticks);
bogdanm 20:4263a77256ae 167 timer->MR[i] = t_off;
bogdanm 20:4263a77256ae 168 }
bogdanm 20:4263a77256ae 169 }
bogdanm 20:4263a77256ae 170 timer->TCR = TCR_CNT_EN;
bogdanm 20:4263a77256ae 171 }
bogdanm 20:4263a77256ae 172
bogdanm 20:4263a77256ae 173 void pwmout_pulsewidth(pwmout_t* obj, float seconds) {
bogdanm 20:4263a77256ae 174 pwmout_pulsewidth_us(obj, seconds * 1000000.0f);
bogdanm 20:4263a77256ae 175 }
bogdanm 20:4263a77256ae 176
bogdanm 20:4263a77256ae 177 void pwmout_pulsewidth_ms(pwmout_t* obj, int ms) {
bogdanm 20:4263a77256ae 178 pwmout_pulsewidth_us(obj, ms * 1000);
bogdanm 20:4263a77256ae 179 }
bogdanm 20:4263a77256ae 180
bogdanm 20:4263a77256ae 181 void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
bogdanm 20:4263a77256ae 182 uint32_t t_on = (uint32_t)(((uint64_t)SystemCoreClock * (uint64_t)us) / (uint64_t)1000000);
bogdanm 20:4263a77256ae 183 timer_mr tid = pwm_timer_map[obj->pwm];
bogdanm 20:4263a77256ae 184 LPC_TMR_TypeDef *timer = Timers[tid.timer];
bogdanm 20:4263a77256ae 185
bogdanm 20:4263a77256ae 186 timer->TCR = TCR_RESET;
bogdanm 20:4263a77256ae 187 if (t_on > timer->MR3) {
bogdanm 20:4263a77256ae 188 pwmout_period_us(obj, us);
bogdanm 20:4263a77256ae 189 }
bogdanm 20:4263a77256ae 190 uint32_t t_off = timer->MR3 - t_on;
bogdanm 20:4263a77256ae 191 timer->MR[tid.mr] = t_off;
bogdanm 20:4263a77256ae 192 timer->TCR = TCR_CNT_EN;
bogdanm 20:4263a77256ae 193 }