stm32l4xx + HSI48 Topic is solved

[geoffrey.brown]

The support for using the HSI48 with USB is slightly broken (there's also no support for CRS, but that's not a big deal). The problem is that in the hal_lld.h file, there's no way to select the HSI48 clock as the source for STM32_48CLK -- here's the relevant code:

Code: Select all

/**
 * @brief   48MHz clock frequency.
 */
#if (STM32_CLK48SEL == STM32_CLK48SEL_NOCLK) || defined(__DOXYGEN__)
#define STM32_48CLK                 0
#elif STM32_CLK48SEL == STM32_CLK48SEL_PLLSAI1
#define STM32_48CLK                 (STM32_PLLSAI1VCO / STM32_PLLSAI1Q_VALUE)
#elif STM32_CLK48SEL == STM32_CLK48SEL_PLL
#define STM32_48CLK                 (STM32_PLLVCO / STM32_PLLQ_VALUE)
#elif STM32_CLK48SEL == STM32_CLK48SEL_MSI
#define STM32_48CLK                 STM32_MSICLK
#else
#error "invalid source selected for 48CLK clock"
#endif
#define STM32_USBCLK                STM32_48CLK

..........
In contrast, the code hal code for the stm32f0xx does provide such a method:

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/**
 * @brief   USB frequency.
 */
#if (STM32_USBSW == STM32_USBSW_HSI48) || defined(__DOXYGEN__)
#define STM32_USBCLK                STM32_HSI48CLK
#elif STM32_USBSW == STM32_USBSW_PCLK
#define STM32_USBCLK                STM32_PLLCLKOUT
#else
#error "invalid source selected for USB clock"
#endif

...........

I wouldn't mind, but I couldn't find a workaround short of hacking the hal_lld.h file which I hate to do. BTW, with a little work, the CRS + USB combo works quite well on the STM32L432.

Geoffrey Brown

[Giovanni]

Hi,

Moving this to "bug reports", if you have a patch please post it here.

Giovanni

[geoffrey.brown]

Here is a patch that does two things:

1) Adds the necessary definitions to STM32L4xx/hal_lld.h
2) If defined, initialized the HSI48 clock in STM32L4xx/hal_lld.c

I didn't attempt to add the CRS code -- it has a number of possible configurations.

diff --git a/os/hal/ports/STM32/STM32L4xx/hal_lld.c b/os/hal/ports/STM32/STM32L4xx/hal_lld.c
index f02d2a3..3196a49 100644
--- a/os/hal/ports/STM32/STM32L4xx/hal_lld.c
+++ b/os/hal/ports/STM32/STM32L4xx/hal_lld.c
@@ -188,6 +188,14 @@ void stm32_clock_init(void) {
; /* Wait until HSI is stable. */
#endif

+#if STM32_HSI48_ENABLED
+ /* HSI48 activation.*/
+ RCC->CCIPR |= RCC_CCIPR_CLK48SEL;
+ RCC->CRRCR |= RCC_CRRCR_HSI48ON;
+ while (!(RCC->CRRCR & RCC_CRRCR_HSI48RDY))
+ ; /* Waits until HSI48 is stable. */
+#endif
+
#if STM32_HSE_ENABLED
#if defined(STM32_HSE_BYPASS)
/* HSE Bypass.*/
diff --git a/os/hal/ports/STM32/STM32L4xx/hal_lld.h b/os/hal/ports/STM32/STM32L4xx/hal_lld.h
index d78b157..5c4701f 100644
--- a/os/hal/ports/STM32/STM32L4xx/hal_lld.h
+++ b/os/hal/ports/STM32/STM32L4xx/hal_lld.h
@@ -72,6 +72,7 @@
* @{
*/
#define STM32_HSI16CLK 16000000 /**< High speed internal clock. */
+#define STM32_HSI48CLK 48000000 /**< 48MHz speed internal clock.*/
#define STM32_LSICLK 32000 /**< Low speed internal clock. */
/** @} */

@@ -362,6 +363,13 @@
#endif

/**
+ * @brief Enables or disables the HSI48 clock source.
+ */
+#if !defined(STM32_HSI48_ENABLED) || defined(__DOXYGEN__)
+#define STM32_HSI48_ENABLED FALSE
+#endif
+
+/**
* @brief Enables or disables the LSI clock source.
*/
#if !defined(STM32_LSI_ENABLED) || defined(__DOXYGEN__)
@@ -1963,8 +1971,13 @@
/**
* @brief 48MHz clock frequency.
*/
+
#if (STM32_CLK48SEL == STM32_CLK48SEL_NOCLK) || defined(__DOXYGEN__)
+#if (STM32_HSI48_ENABLED == TRUE)
+#define STM32_48CLK STM32_HSI48CLK
+#else
#define STM32_48CLK 0
+#endif
#elif STM32_CLK48SEL == STM32_CLK48SEL_PLLSAI1
#define STM32_48CLK (STM32_PLLSAI1VCO / STM32_PLLSAI1Q_VALUE)
#elif STM32_CLK48SEL == STM32_CLK48SEL_PLL

[Giovanni]

bump

[RoccoMarco]

Hi,
are you working on trunk?

STM32L4 has not something called HSI48 but MSI48. It is supported is currently used in USB-CDC demo as USB clock source. I reworked whole clock three six months ago with Giovanni.

This is the mcuconf os chibios_trunk\teshal\STM32\STM32L4xx\USB-CDC

/*
* HAL driver system settings.
*/

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#define STM32_NO_INIT                       FALSE
#define STM32_VOS                           STM32_VOS_RANGE1
#define STM32_PVD_ENABLE                    FALSE
#define STM32_PLS                           STM32_PLS_LEV0
#define STM32_HSI16_ENABLED                 TRUE
#define STM32_LSI_ENABLED                   TRUE
#define STM32_HSE_ENABLED                   FALSE
#define STM32_LSE_ENABLED                   TRUE
#define STM32_MSIPLL_ENABLED                TRUE
#define STM32_ADC_CLOCK_ENABLED             TRUE
#define STM32_USB_CLOCK_ENABLED             TRUE
#define STM32_SAI1_CLOCK_ENABLED            TRUE
#define STM32_SAI2_CLOCK_ENABLED            TRUE
#define STM32_MSIRANGE                      STM32_MSIRANGE_48M
#define STM32_MSISRANGE                     STM32_MSISRANGE_4M
#define STM32_SW                            STM32_SW_PLL
#define STM32_PLLSRC                        STM32_PLLSRC_HSI16
#define STM32_PLLM_VALUE                    4
#define STM32_PLLN_VALUE                    80
#define STM32_PLLP_VALUE                    7
#define STM32_PLLQ_VALUE                    6
#define STM32_PLLR_VALUE                    4
#define STM32_HPRE                          STM32_HPRE_DIV1
#define STM32_PPRE1                         STM32_PPRE1_DIV1
#define STM32_PPRE2                         STM32_PPRE2_DIV1
#define STM32_STOPWUCK                      STM32_STOPWUCK_MSI
#define STM32_MCOSEL                        STM32_MCOSEL_NOCLOCK
#define STM32_MCOPRE                        STM32_MCOPRE_DIV1
#define STM32_LSCOSEL                       STM32_LSCOSEL_NOCLOCK
#define STM32_PLLSAI1N_VALUE                72
#define STM32_PLLSAI1P_VALUE                7
#define STM32_PLLSAI1Q_VALUE                6
#define STM32_PLLSAI1R_VALUE                6
#define STM32_PLLSAI2N_VALUE                72
#define STM32_PLLSAI2P_VALUE                7
#define STM32_PLLSAI2R_VALUE                6
#define STM32_USART1SEL                     STM32_USART1SEL_SYSCLK
#define STM32_USART2SEL                     STM32_USART2SEL_SYSCLK
#define STM32_USART3SEL                     STM32_USART3SEL_SYSCLK
#define STM32_UART4SEL                      STM32_UART4SEL_SYSCLK
#define STM32_UART5SEL                      STM32_UART5SEL_SYSCLK
#define STM32_LPUART1SEL                    STM32_LPUART1SEL_SYSCLK
#define STM32_I2C1SEL                       STM32_I2C1SEL_SYSCLK
#define STM32_I2C2SEL                       STM32_I2C2SEL_SYSCLK
#define STM32_I2C3SEL                       STM32_I2C3SEL_SYSCLK
#define STM32_LPTIM1SEL                     STM32_LPTIM1SEL_PCLK1
#define STM32_LPTIM2SEL                     STM32_LPTIM2SEL_PCLK1
#define STM32_SAI1SEL                       STM32_SAI1SEL_OFF
#define STM32_SAI2SEL                       STM32_SAI2SEL_OFF
#define STM32_CLK48SEL                      STM32_CLK48SEL_MSI
#define STM32_ADCSEL                        STM32_ADCSEL_SYSCLK
#define STM32_SWPMI1SEL                     STM32_SWPMI1SEL_PCLK1
#define STM32_DFSDMSEL                      STM32_DFSDMSEL_PCLK1
#define STM32_RTCSEL                        STM32_RTCSEL_LSI

This is guide to switch on trunk and update it:
How to switch to the development version of ChibiOS.

I am going to mark this as solved but feel free to reply for any concern...

[geoffrey.brown]

I think you may have missed the fundamental point -- the code that enables the selection of the USB clock source is incomplete -- it does not allow selection of the dedicated internal 48Mhz oscillator (whatever you've called it in the code).

Geoffrey

[Giovanni]

Reopened...

Giovanni

[RoccoMarco]

Hi,
to clock the USB you just have to enable MSI and set MSI range as 48 MHz, then select CKL48 source as MSI

in mcuconf this is done in this way:

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#define STM32_MSIRANGE                      STM32_MSIRANGE_48M


+

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#define STM32_CLK48SEL                      STM32_CLK48SEL_MSI

am I missing something?

[RoccoMarco]

Ok,
I have figure out the problem. You are talking about STM32L4x2 which is not completely supported.

I was looking at STM32L4x7 RM which doesn't has HSI48.

We will add support for this new device.

[rvense]

Is availability of hardware a limiting factor in this? I have some self-made boards with STM32L433CC and would be very happy to send one to Italy at my expense. USB powered, some LEDs, and most other I/O broken out - Kicad files here. The 48-pin F042 and L433 are compatible and I have a simple LED blinking example running on boards populated with an L433, but would like to see more complete support for this chip, but am not very familiar with ChibiOS internals.