From ba66a3d63fe54f592bede26ebb8c58e129ab0af6 Mon Sep 17 00:00:00 2001
From: "Andreas \"Paul\" Pauli" <paul@localhost>
Date: Mon, 1 Jun 2015 16:07:00 +0200
Subject: [PATCH] cpu/sam3x8e: add pwm peripheral driver
---
boards/arduino-due/Makefile.features | 1 +
boards/arduino-due/include/periph_conf.h | 32 +++
cpu/sam3x8e/periph/pwm.c | 291 +++++++++++++++++++++++
3 files changed, 324 insertions(+)
create mode 100644 cpu/sam3x8e/periph/pwm.c
diff --git a/boards/arduino-due/Makefile.features b/boards/arduino-due/Makefile.features
index e75ff321ac..8acd3cf9b5 100644
--- a/boards/arduino-due/Makefile.features
+++ b/boards/arduino-due/Makefile.features
@@ -1,6 +1,7 @@
FEATURES_PROVIDED += cpp
FEATURES_PROVIDED += periph_uart
FEATURES_PROVIDED += periph_gpio
+FEATURES_PROVIDED += periph_pwm
FEATURES_PROVIDED += periph_spi
FEATURES_PROVIDED += periph_random
FEATURES_MCU_GROUP = cortex_m3_1
diff --git a/boards/arduino-due/include/periph_conf.h b/boards/arduino-due/include/periph_conf.h
index bf80529e77..6d1fa45f28 100644
--- a/boards/arduino-due/include/periph_conf.h
+++ b/boards/arduino-due/include/periph_conf.h
@@ -15,6 +15,7 @@
*
* @author Hauke Petersen <hauke.petersen@fu-berlin.de>
* @author Peter Kietzmann <peter.kietzmann@haw-hamburg.de>
+ * @author Andreas "Paul" Pauli <andreas.pauli@haw-hamburg.de>
*/
#ifndef __PERIPH_CONF_H
@@ -342,6 +343,37 @@ extern "C" {
#define GPIO_B21_MAP 31
/** @} */
+/**
+ * @name PWM configuration
+ * @{
+ */
+#define PWM_NUMOF (1U)
+#define PWM_0_EN (1)
+#define PWM_MAX_VALUE (0xffff)
+#define PWM_MAX_CHANNELS (4U)
+
+/* PWM_0 configuration */
+#define PWM_0_DEV PWM
+#define PWM_0_PID ID_PWM
+#define PWM_0_CHANNELS (4U)
+#define PWM_0_DEV_CH0 (&(PWM_0_DEV->PWM_CH_NUM[4]))
+#define PWM_0_ENA_CH0 PWM_ENA_CHID4
+#define PWM_0_PORT_CH0 PIOC
+#define PWM_0_PIN_CH0 PIO_PC21B_PWML4
+#define PWM_0_DEV_CH1 (&(PWM_0_DEV->PWM_CH_NUM[5]))
+#define PWM_0_ENA_CH1 PWM_ENA_CHID5
+#define PWM_0_PORT_CH1 PIOC
+#define PWM_0_PIN_CH1 PIO_PC22B_PWML5
+#define PWM_0_DEV_CH2 (&(PWM_0_DEV->PWM_CH_NUM[6]))
+#define PWM_0_ENA_CH2 PWM_ENA_CHID6
+#define PWM_0_PORT_CH2 PIOC
+#define PWM_0_PIN_CH2 PIO_PC23B_PWML6
+#define PWM_0_DEV_CH3 (&(PWM_0_DEV->PWM_CH_NUM[7]))
+#define PWM_0_ENA_CH3 PWM_ENA_CHID7
+#define PWM_0_PORT_CH3 PIOC
+#define PWM_0_PIN_CH3 PIO_PC24B_PWML7
+/** @} */
+
#ifdef __cplusplus
}
#endif
diff --git a/cpu/sam3x8e/periph/pwm.c b/cpu/sam3x8e/periph/pwm.c
new file mode 100644
index 0000000000..22572620f5
--- /dev/null
+++ b/cpu/sam3x8e/periph/pwm.c
@@ -0,0 +1,291 @@
+/*
+ * Copyright (C) 2015 Hamburg University of Applied Sciences
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser General
+ * Public License v2.1. See the file LICENSE in the top level directory for more
+ * details.
+ */
+
+/**
+ * @ingroup cpu_sam3x8e
+ * @{
+ *
+ * @file
+ * @brief CPU specific low-level PWM driver implementation for the SAM3X8E
+ *
+ * @author Andreas "Paul" Pauli <andreas.pauli@haw-hamburg.de>
+ *
+ * @}
+ */
+#include <stdint.h>
+#include "board.h"
+#include "periph/pwm.h"
+
+/*
+ * guard file in case no PWM device is defined,
+ */
+#if PWM_NUMOF && PWM_0_EN
+
+#define ERR_INIT_MODE (-1)
+#define ERR_INIT_BWTH (-2)
+#define ERR_SET_CHAN (-1)
+#define MCK_DIV_LB_MAX (10U)
+
+int pwm_init(pwm_t dev, pwm_mode_t mode,
+ unsigned int frequency,
+ unsigned int resolution)
+{
+
+ int32_t retval = ERR_INIT_MODE; /* Worst/First case */
+ uint32_t pwm_clk = 0; /* Desired/real pwm_clock */
+ uint32_t diva = 1; /* Candidate for 8bit divider */
+ uint32_t prea = 0; /* Candidate for clock select */
+
+ switch (dev) {
+#if PWM_0_EN
+
+ case PWM_0:
+ break;
+#endif
+
+ default:
+ return ERR_INIT_MODE;
+ }
+
+ /*
+ * Mode check.
+ * Only PW_LEFT -which is hw default- supported for now.
+ */
+ switch (mode) {
+ case PWM_LEFT:
+ break;
+
+ case PWM_RIGHT:
+ case PWM_CENTER:
+ default:
+ return ERR_INIT_MODE;
+ }
+
+ /* Should check if "|log_2 frequency|+|log_2 resolution| <= 32" */
+ pwm_clk = frequency * resolution;
+
+ /*
+ * The pwm provides 11 prescaled clocks with (MCK/2^prea | prea=[0,10])
+ * and a divider (diva) with a denominator range [1,255] in line.
+ */
+ if (F_CPU < pwm_clk) { /* Have to cut down resulting frequency. */
+ frequency = F_CPU / resolution;
+ }
+ else { /* Estimate prescaler and divider. */
+ diva = F_CPU / pwm_clk;
+
+ while ((prea < MCK_DIV_LB_MAX) && (~0xff & diva)) {
+ prea = prea + 1;
+ diva = diva >> 1;
+ }
+
+ frequency = F_CPU / ((resolution * diva) << prea);
+ }
+
+ retval = frequency;
+
+ /* Activate PWM block by enabling it's clock. */
+ PMC->PMC_PCER1 = PMC_PCER1_PID36;
+
+ /* Unlock User Interface */
+ PWM_0_DEV->PWM_WPCR = PWM_ENA_CHID0;
+
+ /* Disable all channels to allow CPRD updates. */
+ PWM_0_DEV->PWM_DIS = 0xff;
+
+ /* Step 2. Configure clock generator */
+ PWM_0_DEV->PWM_CLK = PWM_CLK_PREA(prea) | PWM_CLK_DIVA(diva) |
+ (~(PWM_CLK_PREA_Msk | PWM_CLK_DIVA_Msk) &
+ PWM_0_DEV->PWM_CLK);
+
+ /* +++++++++++ Configure and init channels +++++++++++++++ */
+
+ /* Set clock source, resolution, duty-cycle and enable */
+#if PWM_0_CHANNELS > 0
+ PWM_0_DEV_CH0->PWM_CMR = PWM_CMR_CPRE_CLKA;
+ PWM_0_DEV_CH0->PWM_CPRD = resolution - 1;
+ PWM_0_DEV_CH0->PWM_CDTY = 0;
+ PWM_0_DEV->PWM_ENA = PWM_0_ENA_CH0;
+#endif
+#if PWM_0_CHANNELS > 1
+ PWM_0_DEV_CH1->PWM_CMR = PWM_CMR_CPRE_CLKA;
+ PWM_0_DEV_CH1->PWM_CPRD = resolution - 1;
+ PWM_0_DEV_CH1->PWM_CDTY = 0;
+ PWM_0_DEV->PWM_ENA = PWM_0_ENA_CH1;
+#endif
+#if PWM_0_CHANNELS > 2
+ PWM_0_DEV_CH2->PWM_CMR = PWM_CMR_CPRE_CLKA;
+ PWM_0_DEV_CH2->PWM_CPRD = resolution - 1;
+ PWM_0_DEV_CH2->PWM_CDTY = 0;
+ PWM_0_DEV->PWM_ENA = PWM_0_ENA_CH2;
+#endif
+#if PWM_0_CHANNELS > 3
+ PWM_0_DEV_CH3->PWM_CMR = PWM_CMR_CPRE_CLKA;
+ PWM_0_DEV_CH3->PWM_CPRD = resolution - 1;
+ PWM_0_DEV_CH3->PWM_CDTY = 0;
+ PWM_0_DEV->PWM_ENA = PWM_0_ENA_CH3;
+#endif
+
+ /* +++++++++++ Configure and init channels ready++++++++++ */
+
+
+ /*
+ * Disable GPIO and set peripheral A/B ("0/1") for pwm channel pins.
+ */
+#if PWM_0_CHANNELS > 0
+ PWM_0_PORT_CH0->PIO_PDR |= PWM_0_PIN_CH0;
+ PWM_0_PORT_CH0->PIO_ABSR |= PWM_0_PIN_CH0;
+#endif
+#if PWM_0_CHANNELS > 1
+ PWM_0_PORT_CH1->PIO_PDR |= PWM_0_PIN_CH1;
+ PWM_0_PORT_CH1->PIO_ABSR |= PWM_0_PIN_CH1;
+#endif
+#if PWM_0_CHANNELS > 2
+ PWM_0_PORT_CH2->PIO_PDR |= PWM_0_PIN_CH2;
+ PWM_0_PORT_CH2->PIO_ABSR |= PWM_0_PIN_CH2;
+#endif
+#if PWM_0_CHANNELS > 3
+ PWM_0_PORT_CH3->PIO_PDR |= PWM_0_PIN_CH3;
+ PWM_0_PORT_CH3->PIO_ABSR |= PWM_0_PIN_CH3;
+#endif
+
+ return retval;
+}
+
+/*
+ * Update duty-cycle in channel with value.
+ * If value is larger than resolution set by pwm_init() it is cropped.
+ */
+int pwm_set(pwm_t dev, int channel, unsigned int value)
+{
+
+ int retval = ERR_SET_CHAN; /* Worst case */
+ uint32_t period = 0; /* Store pwm period */
+ PwmCh_num *chan = (void *)0; /* Addressed channel. */
+
+ switch (dev) {
+#if PWM_0_EN
+
+ case PWM_0:
+ break;
+#endif
+
+ default:
+ return ERR_SET_CHAN;
+ }
+
+
+ switch (channel) {
+#if PWM_0_CHANNELS > 0
+
+ case 0:
+ chan = PWM_0_DEV_CH0;
+ break;
+#endif
+#if PWM_0_CHANNELS > 1
+
+ case 1:
+ chan = PWM_0_DEV_CH1;
+ break;
+#endif
+#if PWM_0_CHANNELS > 2
+
+ case 2:
+ chan = PWM_0_DEV_CH2;
+ break;
+#endif
+#if PWM_0_CHANNELS > 3
+
+ case 3:
+ chan = PWM_0_DEV_CH3;
+ break;
+#endif
+
+ default:
+ retval = ERR_SET_CHAN;
+ }
+
+ if (chan) {
+ period = chan->PWM_CPRD & PWM_CPRD_CPRD_Msk;
+
+
+ if (value < period) {
+ chan->PWM_CDTYUPD = value;
+ }
+ else { /* Value Out of range. Clip silent as required by interface. */
+ chan->PWM_CDTYUPD = period;
+ }
+
+ retval = 0;
+ }
+
+ return retval;
+}
+
+/*
+ * Continue operation.
+ */
+void pwm_start(pwm_t dev)
+{
+ switch (dev) {
+#if PWM_0_EN
+
+ case PWM_0:
+ PMC->PMC_PCER1 |= PMC_PCER1_PID36;
+ break;
+#endif
+ }
+}
+
+/*
+ * Stop operation and set output to 0.
+ */
+void pwm_stop(pwm_t dev)
+{
+ switch (dev) {
+#if PWM_0_EN
+
+ case PWM_0:
+ PMC->PMC_PCDR1 |= PMC_PCDR1_PID36;
+ break;
+#endif
+ }
+}
+
+/*
+ * The device is reactivated by by clocking the device block.
+ * Operation continues where it has been stopped by poweroff.
+ */
+void pwm_poweron(pwm_t dev)
+{
+ switch (dev) {
+#if PWM_0_EN
+
+ case PWM_0:
+ PMC->PMC_PCER1 |= PMC_PCER1_PID36;
+ break;
+#endif
+ }
+}
+
+/*
+ * The device is set to power saving mode by disabling the clock.
+ */
+void pwm_poweroff(pwm_t dev)
+{
+ switch (dev) {
+#if PWM_0_EN
+
+ case PWM_0:
+ PMC->PMC_PCDR1 |= PMC_PCDR1_PID36;
+ break;
+#endif
+ }
+}
+
+#endif /* PWM_NUMOF */
--
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