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STM32 quad encoder: Don't calculate the timer prescaler value at runtime; pre-calculate it at compiler time 

git-svn-id: https://nuttx.svn.sourceforge.net/svnroot/nuttx/trunk@4424 7fd9a85b-ad96-42d3-883c-3090e2eb8679
This commit is contained in:
patacongo 2012-02-25 00:53:24 +00:00
parent eccf19e0af
commit 9c338d809e
1 changed files with 39 additions and 23 deletions
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62
nuttx/arch/arm/src/stm32/stm32_qencoder.c
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@ -65,6 +65,33 @@
/************************************************************************************
* Pre-processor Definitions
************************************************************************************/
/* Clocking *************************************************************************/
/* The CLKOUT value should not exceed the CLKIN value */
#if defined(CONFIG_STM32_TIM1_QE) && CONFIG_STM32_TIM1_QECLKOUT > STM32_APB2_TIM1_CLKIN
# warning "CONFIG_STM32_TIM1_QECLKOUT exceeds STM32_APB2_TIM1_CLKIN"
#endif
#if defined(CONFIG_STM32_TIM2_QE) && CONFIG_STM32_TIM2_QECLKOUT > STM32_APB1_TIM2_CLKIN
# warning "CONFIG_STM32_TIM2_QECLKOUT exceeds STM32_APB2_TIM2_CLKIN"
#endif
#if defined(CONFIG_STM32_TIM3_QE) && CONFIG_STM32_TIM3_QECLKOUT > STM32_APB1_TIM3_CLKIN
# warning "CONFIG_STM32_TIM3_QECLKOUT exceeds STM32_APB2_TIM3_CLKIN"
#endif
#if defined(CONFIG_STM32_TIM4_QE) && CONFIG_STM32_TIM4_QECLKOUT > STM32_APB1_TIM4_CLKIN
# warning "CONFIG_STM32_TIM4_QECLKOUT exceeds STM32_APB2_TIM4_CLKIN"
#endif
#if defined(CONFIG_STM32_TIM5_QE) && CONFIG_STM32_TIM5_QECLKOUT > STM32_APB1_TIM5_CLKIN
# warning "CONFIG_STM32_TIM5_QECLKOUT exceeds STM32_APB2_TIM5_CLKIN"
#endif
#if defined(CONFIG_STM32_TIM8_QE) && CONFIG_STM32_TIM8_QECLKOUT > STM32_APB2_TIM8_CLKIN
# warning "CONFIG_STM32_TIM8_QECLKOUT exceeds STM32_APB2_TIM6_CLKIN"
#endif
/* Debug ****************************************************************************/
/* Non-standard debug that may be enabled just for testing the quadrature encoder */
@ -110,7 +137,7 @@ struct stm32_qeconfig_s
uint16_t ti2cfg; /* TI2 input pin configuration (16-bit encoding) */
#endif
uint32_t base; /* Register base address */
uint32_t clkin; /* Timer input clock frequency */
uint32_t psc; /* Timer input clock prescaler */
xcpt_t handler; /* Interrupt handler for this IRQ */
};
@ -202,7 +229,7 @@ static const struct stm32_qeconfig_s g_tim1config =
.timid = 1,
.irq = STM32_IRQ_TIM1UP,
.base = STM32_TIM1_BASE,
.clkin = STM32_APB2_TIM1_CLKIN,
.psc = (STM32_APB2_TIM1_CLKIN / CONFIG_STM32_TIM1_QECLKOUT) - 1,
.ti1cfg = GPIO_TIM1_CH1IN,
.ti2cfg = GPIO_TIM1_CH2IN,
.handler = stm32_tim1interrupt,
@ -223,7 +250,7 @@ static const struct stm32_qeconfig_s g_tim2config =
.timid = 2,
.irq = STM32_IRQ_TIM2,
.base = STM32_TIM2_BASE,
.clkin = STM32_APB1_TIM2_CLKIN,
.psc = (STM32_APB1_TIM2_CLKIN / CONFIG_STM32_TIM2_QECLKOUT) - 1,
.ti1cfg = GPIO_TIM2_CH1IN,
.ti2cfg = GPIO_TIM2_CH2IN,
.handler = stm32_tim2interrupt,
@ -244,7 +271,7 @@ static const struct stm32_qeconfig_s g_tim3config =
.timid = 3,
.irq = STM32_IRQ_TIM3,
.base = STM32_TIM3_BASE,
.clkin = STM32_APB1_TIM3_CLKIN,
.psc = (STM32_APB1_TIM3_CLKIN / CONFIG_STM32_TIM3_QECLKOUT) - 1,
.ti1cfg = GPIO_TIM3_CH1IN,
.ti2cfg = GPIO_TIM3_CH2IN,
.handler = stm32_tim3interrupt,
@ -265,7 +292,7 @@ static const struct stm32_qeconfig_s g_tim4config =
.timid = 4,
.irq = STM32_IRQ_TIM4,
.base = STM32_TIM4_BASE,
.clkin = STM32_APB1_TIM4_CLKIN,
.psc = (STM32_APB1_TIM4_CLKIN / CONFIG_STM32_TIM4_QECLKOUT) - 1,
.ti1cfg = GPIO_TIM4_CH1IN,
.ti2cfg = GPIO_TIM4_CH2IN,
.handler = stm32_tim4interrupt,
@ -286,7 +313,7 @@ static const struct stm32_qeconfig_s g_tim5config =
.timid = 5,
.irq = STM32_IRQ_TIM5,
.base = STM32_TIM5_BASE,
.clkin = STM32_APB1_TIM5_CLKIN,
.psc = (STM32_APB1_TIM5_CLKIN / CONFIG_STM32_TIM5_QECLKOUT) - 1,
.ti1cfg = GPIO_TIM5_CH1IN,
.ti2cfg = GPIO_TIM5_CH2IN,
.handler = stm32_tim5interrupt,
@ -307,7 +334,7 @@ static const struct stm32_qeconfig_s g_tim8config =
.timid = 8,
.irq = STM32_IRQ_TIM8UP,
.base = STM32_TIM8_BASE,
.clkin = STM32_APB2_TIM8_CLKIN,
.psc = (STM32_APB2_TIM8_CLKIN / CONFIG_STM32_TIM8_QECLKOUT) - 1,
.ti1cfg = GPIO_TIM8_CH1IN,
.ti2cfg = GPIO_TIM8_CH2IN,
.handler = stm32_tim8interrupt,
@ -608,7 +635,6 @@ static int stm32_tim8interrupt(int irq, FAR void *context)
static int stm32_setup(FAR struct qe_lowerhalf_s *lower)
{
FAR struct stm32_lowerhalf_s *priv = (FAR struct stm32_lowerhalf_s *)lower;
uint32_t psc;
uint16_t dier;
uint16_t smcr;
uint16_t ccmr1;
@ -634,23 +660,13 @@ static int stm32_setup(FAR struct qe_lowerhalf_s *lower)
stm32_putreg32(priv, STM32_GTIM_ARR_OFFSET, 0xffff);
/* Calculate and set the timer rescaler value. The clock input value (CLKIN) is
* based on the peripheral clock (PCLK) and a multiplier. These CLKIN values are
* provided in the board.h file. The prescaler value is then that CLKIN value
* divided by the the configured CLKOUT value (minus one)
*
* For example:
* TIM8 is APB2. Suppose HCLK==SYSCLOCK, HCLK is 168MHz and PCLK2 is HCLK/2, then
* the TIM8 CLKIN value will be 2*HCLK or 168MHz.
*
* If the desired CLKOUT is 28MHz, then the prescaler would be 5. NOTE that this
* calculation would fail if the CLKIN value is less than the CLKOUT value.
/* Set the timerp rescaler value. The clock input value (CLKIN) is based on the
* peripheral clock (PCLK) and a multiplier. These CLKIN values are provided in
* the board.h file. The prescaler value is then that CLKIN value divided by the
* configured CLKOUT value (minus one)
*/
DEBUGASSERT(priv->clkin >= CONFIG_STM32_TIM_QECLKOUT);
psc = (priv->clkin / CONFIG_STM32_TIM_QECLKOUT) - 1;
stm32_putreg16(priv, STM32_GTIM_PSC_OFFSET, (uint16_t)psc);
stm32_putreg16(priv, STM32_GTIM_PSC_OFFSET, (uint16_t)priv->psc);
#if defined(CONFIG_STM32_TIM1_QE) || defined(CONFIG_STM32_TIM8_QE)
if (priv->config->timid == 1 || priv->config->timid == 8)