AVR variants

[JetForMe]

Hi. Should I be making separate platform directories for variants of the AVR? In my case, I made, next to the AVR directory, a copy called ATmegaXX4. I've modified the serial_lld.* files because there are two USARTS on that platform.

I notice in the ports/GCC/AVR/chcore.h file, there is a CH_CORE_VARIANT_NAME, but I don't know if I want to try to #if all the variants in the driver code.

[Giovanni]

The AVR support is pretty basic, if you want to extend it to the whole family then you should do something like the STM32 HAL which support all the STM32 sub-families.
It has the following structure:
./STM32 (STM32 generic drivers, common to all).
./STM32F1xx (STM32F1xx specific drivers and capability header).
./STM32F2xx (STM32F2xx specific drivers and capability header).
./STM32F4xx (STM32F4xx specific drivers and capability header).
./STM32L1xx (STM32L1xx specific drivers and capability header).

That "capability header" (a section in hal_lld.h) contains a series of definitions detailing what is present in that specific sub-family, this is an example for the STM32L1xx:

Code: Select all

/*===========================================================================*/
/* Platform capabilities.                                                    */
/*===========================================================================*/

/**
 * @name    STM32L1xx capabilities
 * @{
 */
/* ADC attributes.*/
#define STM32_HAS_ADC1          TRUE
#define STM32_HAS_ADC2          FALSE
#define STM32_HAS_ADC3          FALSE

/* CAN attributes.*/
#define STM32_HAS_CAN1          FALSE
#define STM32_HAS_CAN2          FALSE

/* DAC attributes.*/
#define STM32_HAS_DAC           TRUE

/* DMA attributes.*/
#define STM32_ADVANCED_DMA      FALSE
#define STM32_HAS_DMA1          TRUE
#define STM32_HAS_DMA2          FALSE

/* ETH attributes.*/
#define STM32_HAS_ETH           FALSE

/* EXTI attributes.*/
#define STM32_EXTI_NUM_CHANNELS 23

/* GPIO attributes.*/
#define STM32_HAS_GPIOA         TRUE
#define STM32_HAS_GPIOB         TRUE
#define STM32_HAS_GPIOC         TRUE
#define STM32_HAS_GPIOD         TRUE
#define STM32_HAS_GPIOE         TRUE
#define STM32_HAS_GPIOF         FALSE
#define STM32_HAS_GPIOG         FALSE
#define STM32_HAS_GPIOH         TRUE
#define STM32_HAS_GPIOI         FALSE

/* I2C attributes.*/
#define STM32_HAS_I2C1          TRUE
#define STM32_I2C1_RX_DMA_MSK   (STM32_DMA_STREAM_ID_MSK(1, 7))
#define STM32_I2C1_RX_DMA_CHN   0x00000000
#define STM32_I2C1_TX_DMA_MSK   (STM32_DMA_STREAM_ID_MSK(1, 6))
#define STM32_I2C1_TX_DMA_CHN   0x00000000

#define STM32_HAS_I2C2          TRUE
#define STM32_I2C2_RX_DMA_MSK   (STM32_DMA_STREAM_ID_MSK(1, 5))
#define STM32_I2C2_RX_DMA_CHN   0x00000000
#define STM32_I2C2_TX_DMA_MSK   (STM32_DMA_STREAM_ID_MSK(1, 4))
#define STM32_I2C2_TX_DMA_CHN   0x00000000

#define STM32_HAS_I2C3          FALSE
#define STM32_I2C3_RX_DMA_MSK   0
#define STM32_I2C3_RX_DMA_CHN   0x00000000
#define STM32_I2C3_TX_DMA_MSK   0
#define STM32_I2C3_TX_DMA_CHN   0x00000000

/* RTC attributes.*/
#define STM32_HAS_RTC           TRUE
#define STM32_RTC_HAS_SUBSECONDS FALSE

/* SDIO attributes.*/
#define STM32_HAS_SDIO          FALSE

/* SPI attributes.*/
#define STM32_HAS_SPI1          TRUE
#define STM32_SPI1_RX_DMA_MSK   STM32_DMA_STREAM_ID_MSK(1, 2)
#define STM32_SPI1_RX_DMA_CHN   0x00000000
#define STM32_SPI1_TX_DMA_MSK   STM32_DMA_STREAM_ID_MSK(1, 3)
#define STM32_SPI1_TX_DMA_CHN   0x00000000

#define STM32_HAS_SPI2          TRUE
#define STM32_SPI2_RX_DMA_MSK   STM32_DMA_STREAM_ID_MSK(1, 4)
#define STM32_SPI2_RX_DMA_CHN   0x00000000
#define STM32_SPI2_TX_DMA_MSK   STM32_DMA_STREAM_ID_MSK(1, 5)
#define STM32_SPI2_TX_DMA_CHN   0x00000000

#define STM32_HAS_SPI3          FALSE
#define STM32_SPI3_RX_DMA_MSK   0
#define STM32_SPI3_RX_DMA_CHN   0x00000000
#define STM32_SPI3_TX_DMA_MSK   0
#define STM32_SPI3_TX_DMA_CHN   0x00000000

/* TIM attributes.*/
#define STM32_HAS_TIM1          FALSE
#define STM32_HAS_TIM2          TRUE
#define STM32_HAS_TIM3          TRUE
#define STM32_HAS_TIM4          TRUE
#define STM32_HAS_TIM5          FALSE
#define STM32_HAS_TIM6          TRUE
#define STM32_HAS_TIM7          TRUE
#define STM32_HAS_TIM8          FALSE
#define STM32_HAS_TIM9          TRUE
#define STM32_HAS_TIM10         TRUE
#define STM32_HAS_TIM11         TRUE
#define STM32_HAS_TIM12         FALSE
#define STM32_HAS_TIM13         FALSE
#define STM32_HAS_TIM14         FALSE
#define STM32_HAS_TIM15         FALSE
#define STM32_HAS_TIM16         FALSE
#define STM32_HAS_TIM17         FALSE

/* USART attributes.*/
#define STM32_HAS_USART1        TRUE
#define STM32_USART1_RX_DMA_MSK (STM32_DMA_STREAM_ID_MSK(1, 5))
#define STM32_USART1_RX_DMA_CHN 0x00000000
#define STM32_USART1_TX_DMA_MSK (STM32_DMA_STREAM_ID_MSK(1, 4))
#define STM32_USART1_TX_DMA_CHN 0x00000000

#define STM32_HAS_USART2        TRUE
#define STM32_USART2_RX_DMA_MSK (STM32_DMA_STREAM_ID_MSK(1, 6))
#define STM32_USART2_RX_DMA_CHN 0x00000000
#define STM32_USART2_TX_DMA_MSK (STM32_DMA_STREAM_ID_MSK(1, 7))
#define STM32_USART2_TX_DMA_CHN 0x00000000

#define STM32_HAS_USART3        TRUE
#define STM32_USART3_RX_DMA_MSK (STM32_DMA_STREAM_ID_MSK(1, 3))
#define STM32_USART3_RX_DMA_CHN 0x00000000
#define STM32_USART3_TX_DMA_MSK (STM32_DMA_STREAM_ID_MSK(1, 2))
#define STM32_USART3_TX_DMA_CHN 0x00000000

#define STM32_HAS_UART4         FALSE
#define STM32_UART4_RX_DMA_MSK  0
#define STM32_UART4_RX_DMA_CHN  0x00000000
#define STM32_UART4_TX_DMA_MSK  0
#define STM32_UART4_TX_DMA_CHN  0x00000000

#define STM32_HAS_UART5         FALSE
#define STM32_UART5_RX_DMA_MSK  0
#define STM32_UART5_RX_DMA_CHN  0x00000000
#define STM32_UART5_TX_DMA_MSK  0
#define STM32_UART5_TX_DMA_CHN  0x00000000

#define STM32_HAS_USART6        FALSE
#define STM32_USART6_RX_DMA_MSK 0
#define STM32_USART6_RX_DMA_CHN 0x00000000
#define STM32_USART6_TX_DMA_MSK 0
#define STM32_USART6_TX_DMA_CHN 0x00000000

/* USB attributes.*/
#define STM32_HAS_USB           TRUE
#define STM32_HAS_OTG1          FALSE
#define STM32_HAS_OTG2          FALSE
/** @} */

The generic device drivers check the above macros in order to include/exclude parts of the code.

Giovanni

[JetForMe]

Part of the problem with AVR is this: The existing AVR refers to the USART constants like "UDE" (I might be making this up). But in the ATmegaXX4 parts, it's "UDE0" and "UDE1". To make a generic driver, there'd be a lot of #if/#else code in the generic driver, it seems. Is that still the best way?

Thanks.

[mabl]

Why not redefine the defines to a unified naming scheme?

[JetForMe]

Maybe, but that just makes it harder for the next person familiar with AVR to understand what's going on (they have to see what each of the renamed defines is).

[Giovanni]

There are instances of incompatible names in the ST headers too. I usually do one of the following:

1) Names normalization.
2) Don't use the headers and redefine the structures in the xxx_lld.h, I do this when the definitions in the vendor files are too dumb to use or plain wrong.

For example:

Code: Select all

/* There are differences in vector names in the various sub-families,
   normalizing.*/
#if defined(STM32F10X_XL)
#define TIM1_BRK_IRQn       TIM1_BRK_TIM9_IRQn
#define TIM1_UP_IRQn        TIM1_UP_TIM10_IRQn
#define TIM1_TRG_COM_IRQn   TIM1_TRG_COM_TIM11_IRQn
#define TIM8_BRK_IRQn       TIM8_BRK_TIM12_IRQn
#define TIM8_UP_IRQn        TIM8_UP_TIM13_IRQn
#define TIM8_TRG_COM_IRQn   TIM8_TRG_COM_TIM14_IRQn

#elif defined(STM32F10X_LD_VL)|| defined(STM32F10X_MD_VL) ||                \
      defined(STM32F10X_HD_VL)
#define TIM1_BRK_IRQn       TIM1_BRK_TIM15_IRQn
#define TIM1_UP_IRQn        TIM1_UP_TIM16_IRQn
#define TIM1_TRG_COM_IRQn   TIM1_TRG_COM_TIM17_IRQn
#endif

[JetForMe]

I suppose I can define a normalized USART0 to be USART when there's only one. That might actually not be so bad. Thanks!