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Added clk_freqs.h for clock related functions 

Serial now also works when PLL/FLL is disabled and extosc is available.

us_ticker tries to divide extosc to 1MHz, otherwise use fast internal
oscillator
pull/140/head
Sissors 2014-01-11 19:10:36 +01:00
parent ebdbf53ba1
commit aa0f7a7026
6 changed files with 135 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

3
libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KL25Z/analogin_api.c
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@ -18,6 +18,7 @@
#include "cmsis.h"
#include "pinmap.h"
#include "error.h"
#include "clk_freqs.h"
#define MAX_FADC 6000000
@ -58,7 +59,7 @@ void analogin_init(analogin_t *obj, PinName pin) {
}
// bus clk
uint32_t PCLK = SystemCoreClock / (((SIM->CLKDIV1 & SIM_CLKDIV1_OUTDIV4_MASK) >> SIM_CLKDIV1_OUTDIV4_SHIFT) + 1);
uint32_t PCLK = bus_frequency();
uint32_t clkdiv;
for (clkdiv = 0; clkdiv < 4; clkdiv++) {
if ((PCLK >> clkdiv) <= MAX_FADC)

91
libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KL25Z/clk_freqs.h Normal file
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@ -0,0 +1,91 @@
/* 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.
*/
#ifndef MBED_CLK_FREQS_H
#define MBED_CLK_FREQS_H
#ifdef __cplusplus
extern "C" {
#endif
//Get the peripheral bus clock frequency
static inline uint32_t bus_frequency(void) {
return SystemCoreClock / (((SIM->CLKDIV1 & SIM_CLKDIV1_OUTDIV4_MASK) >> SIM_CLKDIV1_OUTDIV4_SHIFT) + 1);
}
//Get external oscillator (crystal) frequency
static uint32_t extosc_frequency(void) {
uint32_t MCGClock = SystemCoreClock * (1u + ((SIM->CLKDIV1 & SIM_CLKDIV1_OUTDIV1_MASK) >> SIM_CLKDIV1_OUTDIV1_SHIFT));
if ((MCG->C1 & MCG_C1_CLKS_MASK) == MCG_C1_CLKS(2)) //MCG clock = external reference clock
return MCGClock;
if ((MCG->C1 & MCG_C1_CLKS_MASK) == MCG_C1_CLKS(0)) { //PLL/FLL is selected
uint32_t divider, multiplier;
if ((MCG->C6 & MCG_C6_PLLS_MASK) == 0x0u) { //FLL is selected
if ((MCG->S & MCG_S_IREFST_MASK) == 0x0u) { //FLL uses external reference
divider = (uint8_t)(1u << ((MCG->C1 & MCG_C1_FRDIV_MASK) >> MCG_C1_FRDIV_SHIFT));
if ((MCG->C2 & MCG_C2_RANGE0_MASK) != 0x0u)
divider <<= 5u;
/* Select correct multiplier to calculate the MCG output clock */
switch (MCG->C4 & (MCG_C4_DMX32_MASK | MCG_C4_DRST_DRS_MASK)) {
case 0x0u:
multiplier = 640u;
break;
case 0x20u:
multiplier = 1280u;
break;
case 0x40u:
multiplier = 1920u;
break;
case 0x60u:
multiplier = 2560u;
break;
case 0x80u:
multiplier = 732u;
break;
case 0xA0u:
multiplier = 1464u;
break;
case 0xC0u:
multiplier = 2197u;
break;
case 0xE0u:
default:
multiplier = 2929u;
break;
}
return MCGClock * divider / multiplier;
}
} else { //PLL is selected
divider = (1u + (MCG->C5 & MCG_C5_PRDIV0_MASK));
multiplier = ((MCG->C6 & MCG_C6_VDIV0_MASK) + 24u);
return MCGClock * divider / multiplier;
}
}
//In all other cases either there is no crystal or we cannot determine it
//For example when the FLL is running on the internal reference, and there is also an
//external crystal. However these are unlikely situations
return 0;
}
#ifdef __cplusplus
}
#endif
#endif

3
libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KL25Z/i2c_api.c
View File

@ -18,6 +18,7 @@
#include "cmsis.h"
#include "pinmap.h"
#include "error.h"
#include "clk_freqs.h"
static const PinMap PinMap_I2C_SDA[] = {
{PTE25, I2C_0, 5},
@ -206,7 +207,7 @@ void i2c_frequency(i2c_t *obj, int hz) {
uint32_t ref = 0;
uint8_t i, j;
// bus clk
uint32_t PCLK = SystemCoreClock / (((SIM->CLKDIV1 & SIM_CLKDIV1_OUTDIV4_MASK) >> SIM_CLKDIV1_OUTDIV4_SHIFT) + 1);
uint32_t PCLK = bus_frequency();
uint32_t pulse = PCLK / (hz * 2);
// we look for the values that minimize the error

9
libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KL25Z/serial_api.c
View File

@ -23,6 +23,7 @@
#include "cmsis.h"
#include "pinmap.h"
#include "error.h"
#include "clk_freqs.h"
/******************************************************************************
* INITIALIZATION
@ -70,7 +71,10 @@ void serial_init(serial_t *obj, PinName tx, PinName rx) {
obj->uart = (UARTLP_Type *)uart;
// enable clk
switch (uart) {
case UART_0: SIM->SOPT2 |= SIM_SOPT2_PLLFLLSEL_MASK | (1<<SIM_SOPT2_UART0SRC_SHIFT);
case UART_0: if ((MCG->C1 & MCG_C1_CLKS_MASK) == MCG_C1_CLKS(0)) //PLL/FLL is selected
SIM->SOPT2 |= SIM_SOPT2_PLLFLLSEL_MASK | (1<<SIM_SOPT2_UART0SRC_SHIFT);
else
SIM->SOPT2 |= (2<<SIM_SOPT2_UART0SRC_SHIFT);
SIM->SCGC5 |= SIM_SCGC5_PORTA_MASK; SIM->SCGC4 |= SIM_SCGC4_UART0_MASK; break;
case UART_1: SIM->SCGC5 |= SIM_SCGC5_PORTC_MASK; SIM->SCGC4 |= SIM_SCGC4_UART1_MASK; break;
case UART_2: SIM->SCGC5 |= SIM_SCGC5_PORTD_MASK; SIM->SCGC4 |= SIM_SCGC4_UART2_MASK; break;
@ -119,8 +123,7 @@ void serial_baud(serial_t *obj, int baudrate) {
// Disable UART before changing registers
obj->uart->C2 &= ~(UART_C2_RE_MASK | UART_C2_TE_MASK);
// [TODO] not hardcode this value
uint32_t PCLK = (obj->uart == UART0) ? SystemCoreClock : SystemCoreClock / (((SIM->CLKDIV1 & SIM_CLKDIV1_OUTDIV4_MASK) >> SIM_CLKDIV1_OUTDIV4_SHIFT) + 1);
uint32_t PCLK = (obj->uart == UART0) ? SystemCoreClock : bus_frequency();
// First we check to see if the basic divide with no DivAddVal/MulVal
// ratio gives us an integer result. If it does, we set DivAddVal = 0,

3
libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KL25Z/spi_api.c
View File

@ -20,6 +20,7 @@
#include "cmsis.h"
#include "pinmap.h"
#include "error.h"
#include "clk_freqs.h"
static const PinMap PinMap_SPI_SCLK[] = {
{PTA15, SPI_0, 2},
@ -145,7 +146,7 @@ void spi_frequency(spi_t *obj, int hz) {
uint8_t ref_prescaler = 0;
// bus clk
uint32_t PCLK = SystemCoreClock / (((SIM->CLKDIV1 & SIM_CLKDIV1_OUTDIV4_MASK) >> SIM_CLKDIV1_OUTDIV4_SHIFT) + 1);
uint32_t PCLK = bus_frequency();
uint8_t prescaler = 1;
uint8_t divisor = 2;

36
libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KL25Z/us_ticker.c
View File

@ -16,6 +16,7 @@
#include <stddef.h>
#include "us_ticker_api.h"
#include "PeripheralNames.h"
#include "clk_freqs.h"
static void pit_init(void);
static void lptmr_init(void);
@ -43,8 +44,7 @@ static void pit_init(void) {
PIT->CHANNEL[1].TCTRL |= PIT_TCTRL_TEN_MASK; // Start timer 1
// Use channel 0 as a prescaler for channel 1
uint32_t PCLK = SystemCoreClock / (((SIM->CLKDIV1 & SIM_CLKDIV1_OUTDIV4_MASK) >> SIM_CLKDIV1_OUTDIV4_SHIFT) + 1);
PIT->CHANNEL[0].LDVAL = PCLK / 1000000 - 1;
PIT->CHANNEL[0].LDVAL = bus_frequency() / 1000000 - 1;
PIT->CHANNEL[0].TCTRL = PIT_TCTRL_TEN_MASK; // Start timer 0, disable interrupts
}
@ -77,8 +77,36 @@ static void lptmr_init(void) {
NVIC_EnableIRQ(LPTimer_IRQn);
/* Clock at (1)MHz -> (1)tick/us */
LPTMR0->PSR = LPTMR_PSR_PCS(3); // OSCERCLK -> 8MHz
LPTMR0->PSR |= LPTMR_PSR_PRESCALE(2); // divide by 8
/* Check if the external oscillator can be divided to 1MHz */
uint32_t extosc = extosc_frequency();
if (extosc != 0) { //If external oscillator found
if (extosc % 1000000u == 0) { //If it is a multiple if 1MHz
extosc /= 1000000;
if (extosc == 1) { //1MHz, set timerprescaler in bypass mode
LPTMR0->PSR = LPTMR_PSR_PCS(3) | LPTMR_PSR_PBYP_MASK;
return;
} else { //See if we can divide it to 1MHz
uint32_t divider = 0;
extosc >>= 1;
while (1) {
if (extosc == 1) {
LPTMR0->PSR = LPTMR_PSR_PCS(3) | LPTMR_PSR_PRESCALE(divider);
return;
}
if (extosc % 2 != 0) //If we can't divide by two anymore
break;
divider++;
extosc >>= 1;
}
}
}
}
//No suitable external oscillator clock -> Use fast internal oscillator (4MHz)
MCG->C1 |= MCG_C1_IRCLKEN_MASK;
MCG->C2 |= MCG_C2_IRCS_MASK;
LPTMR0->PSR = LPTMR_PSR_PCS(0) | LPTMR_PSR_PRESCALE(1);
}
void us_ticker_disable_interrupt(void) {