Diff: targets/TARGET_Freescale/TARGET_KLXX/pwmout_api.c

Revision:

0:f269e3021894

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_Freescale/TARGET_KLXX/pwmout_api.c	Sun Oct 23 15:10:02 2016 +0000
@@ -0,0 +1,125 @@
+/* mbed Microcontroller Library
+ * Copyright (c) 2006-2013 ARM Limited
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include "mbed_assert.h"
+#include "pwmout_api.h"
+
+#include "cmsis.h"
+#include "pinmap.h"
+#include "clk_freqs.h"
+#include "PeripheralPins.h"
+
+static float pwm_clock;
+
+void pwmout_init(pwmout_t* obj, PinName pin) {
+    // determine the channel
+    PWMName pwm = (PWMName)pinmap_peripheral(pin, PinMap_PWM);
+    MBED_ASSERT(pwm != (PWMName)NC);
+
+    uint32_t clkdiv = 0;
+    float clkval;
+
+#if defined(TARGET_KL43Z)
+    if (mcgirc_frequency()) {
+        SIM->SOPT2 |= SIM_SOPT2_TPMSRC(3); // Clock source: MCGIRCLK
+        clkval = mcgirc_frequency() / 1000000.0f;
+    } else {
+        SIM->SOPT2 |= SIM_SOPT2_TPMSRC(1); // Clock source: IRC48M
+        clkval = CPU_INT_IRC_CLK_HZ / 1000000.0f;
+    }
+#else
+    if (mcgpllfll_frequency()) {
+        SIM->SOPT2 |= SIM_SOPT2_TPMSRC(1); // Clock source: MCGFLLCLK or MCGPLLCLK
+        clkval = mcgpllfll_frequency() / 1000000.0f;
+    } else {
+        SIM->SOPT2 |= SIM_SOPT2_TPMSRC(2); // Clock source: ExtOsc
+        clkval = extosc_frequency() / 1000000.0f;
+    }
+#endif
+    while (clkval > 1) {
+        clkdiv++;
+        clkval /= 2.0;
+        if (clkdiv == 7)
+            break;
+    }
+    
+    pwm_clock = clkval;
+    unsigned int port  = (unsigned int)pin >> PORT_SHIFT;
+    unsigned int tpm_n = (pwm >> TPM_SHIFT);
+    unsigned int ch_n  = (pwm & 0xFF);
+
+    SIM->SCGC5 |= 1 << (SIM_SCGC5_PORTA_SHIFT + port);
+    SIM->SCGC6 |= 1 << (SIM_SCGC6_TPM0_SHIFT + tpm_n);
+
+    TPM_Type *tpm = (TPM_Type *)(TPM0_BASE + 0x1000 * tpm_n);
+    tpm->SC = TPM_SC_CMOD(1) | TPM_SC_PS(clkdiv); // (clock)MHz / clkdiv ~= (0.75)MHz
+    tpm->CONTROLS[ch_n].CnSC = (TPM_CnSC_MSB_MASK | TPM_CnSC_ELSB_MASK); /* No Interrupts; High True pulses on Edge Aligned PWM */
+
+    obj->CnV = &tpm->CONTROLS[ch_n].CnV;
+    obj->MOD = &tpm->MOD;
+    obj->CNT = &tpm->CNT;
+
+    // default to 20ms: standard for servos, and fine for e.g. brightness control
+    pwmout_period_ms(obj, 20);
+    pwmout_write    (obj, 0);
+
+    // Wire pinout
+    pinmap_pinout(pin, PinMap_PWM);
+}
+
+void pwmout_free(pwmout_t* obj) {}
+
+void pwmout_write(pwmout_t* obj, float value) {
+    if (value < 0.0) {
+        value = 0.0;
+    } else if (value > 1.0) {
+        value = 1.0;
+    }
+
+    *obj->CnV = (uint32_t)((float)(*obj->MOD + 1) * value);
+    *obj->CNT = 0;
+}
+
+float pwmout_read(pwmout_t* obj) {
+    float v = (float)(*obj->CnV) / (float)(*obj->MOD + 1);
+    return (v > 1.0) ? (1.0) : (v);
+}
+
+void pwmout_period(pwmout_t* obj, float seconds) {
+    pwmout_period_us(obj, seconds * 1000000.0f);
+}
+
+void pwmout_period_ms(pwmout_t* obj, int ms) {
+    pwmout_period_us(obj, ms * 1000);
+}
+
+// Set the PWM period, keeping the duty cycle the same.
+void pwmout_period_us(pwmout_t* obj, int us) {
+    float dc = pwmout_read(obj);
+    *obj->MOD = (uint32_t)(pwm_clock * (float)us) - 1;
+    pwmout_write(obj, dc);
+}
+
+void pwmout_pulsewidth(pwmout_t* obj, float seconds) {
+    pwmout_pulsewidth_us(obj, seconds * 1000000.0f);
+}
+
+void pwmout_pulsewidth_ms(pwmout_t* obj, int ms) {
+    pwmout_pulsewidth_us(obj, ms * 1000);
+}
+
+void pwmout_pulsewidth_us(pwmout_t* obj, int us) {
+    *obj->CnV = (uint32_t)(pwm_clock * (float)us);
+}