drivers: uart: stm32: improve STM32L0 support

STM32L0 UARTs are named as STM32F0 ones, but their
clocking is like all other families.

Signed-off-by: Ilya Tagunov <tagunil@gmail.com>

drivers/serial/uart_stm32.c

@@ -360,11 +360,13 @@ DEVICE_AND_API_INIT(uart_stm32_##n, CONFIG_UART_STM32_PORT_##n##_NAME,	\
 									\
 STM32_UART_IRQ_HANDLER(n)
 
-/* STM32F0 Series differs from other STM32FX series in regard to the clock
- * busses used for USARTS and the naming of the corresponding peripheral Enable
- * bitmasks.
+/*
+ * STM32F0 and STM32L0 series differ from other STM32 series by some
+ * peripheral names (UART vs USART). Besides, STM32F0 doesn't have APB2 bus,
+ * so APB1 GRP2 should be accessed instead.
  */
-#ifdef CONFIG_SOC_SERIES_STM32F0X
+#if defined(CONFIG_SOC_SERIES_STM32F0X)
+
 #ifdef CONFIG_UART_STM32_PORT_1
 UART_DEVICE_INIT_STM32(1, STM32_CLOCK_BUS_APB1_2, LL_APB1_GRP2_PERIPH_USART1)
 #endif	/* CONFIG_UART_STM32_PORT_1 */
@@ -397,7 +399,25 @@ UART_DEVICE_INIT_STM32(7, STM32_CLOCK_BUS_APB1_2, LL_APB1_GRP2_PERIPH_USART7)
 UART_DEVICE_INIT_STM32(8, STM32_CLOCK_BUS_APB1_2, LL_APB1_GRP2_PERIPH_USART8)
 #endif /* CONFIG_UART_STM32_PORT_8 */
 
-#else /* CONFIG_SOC_SERIES_STM32F0X */
+#elif defined(CONFIG_SOC_SERIES_STM32L0X)
+
+#ifdef CONFIG_UART_STM32_PORT_1
+UART_DEVICE_INIT_STM32(1, STM32_CLOCK_BUS_APB2, LL_APB2_GRP1_PERIPH_USART1)
+#endif	/* CONFIG_UART_STM32_PORT_1 */
+
+#ifdef CONFIG_UART_STM32_PORT_2
+UART_DEVICE_INIT_STM32(2, STM32_CLOCK_BUS_APB1, LL_APB1_GRP1_PERIPH_USART2)
+#endif	/* CONFIG_UART_STM32_PORT_2 */
+
+#ifdef CONFIG_UART_STM32_PORT_4
+UART_DEVICE_INIT_STM32(4, STM32_CLOCK_BUS_APB1, LL_APB1_GRP1_PERIPH_USART4)
+#endif /* CONFIG_UART_STM32_PORT_4 */
+
+#ifdef CONFIG_UART_STM32_PORT_5
+UART_DEVICE_INIT_STM32(5, STM32_CLOCK_BUS_APB1, LL_APB1_GRP1_PERIPH_USART5)
+#endif /* CONFIG_UART_STM32_PORT_5 */
+
+#else
 
 #ifdef CONFIG_UART_STM32_PORT_1
 UART_DEVICE_INIT_STM32(1, STM32_CLOCK_BUS_APB2, LL_APB2_GRP1_PERIPH_USART1)
@@ -438,4 +458,5 @@ UART_DEVICE_INIT_STM32(9, STM32_CLOCK_BUS_APB2, LL_APB2_GRP1_PERIPH_UART9)
 #ifdef CONFIG_UART_STM32_PORT_10
 UART_DEVICE_INIT_STM32(10, STM32_CLOCK_BUS_APB2, LL_APB2_GRP1_PERIPH_UART10)
 #endif /* CONFIG_UART_STM32_PORT_10 */
-#endif /* CONFIG_SOC_SERIES_STM32F0X */
+
+#endif