include/zephyr/dt-bindings/clock/stm32l1_clock.h

/*
 * Copyright (c) 2022 Linaro Limited
 *
 * SPDX-License-Identifier: Apache-2.0
 */
#ifndef ZEPHYR_INCLUDE_DT_BINDINGS_CLOCK_STM32L1_CLOCK_H_
#define ZEPHYR_INCLUDE_DT_BINDINGS_CLOCK_STM32L1_CLOCK_H_

/** Bus gatting clocks */
#define STM32_CLOCK_BUS_AHB1    0x01c
#define STM32_CLOCK_BUS_APB2    0x020
#define STM32_CLOCK_BUS_APB1    0x024

#define STM32_PERIPH_BUS_MIN	STM32_CLOCK_BUS_AHB1
#define STM32_PERIPH_BUS_MAX	STM32_CLOCK_BUS_APB1

/** Peripheral clock sources */
/* RM0038.pdf, §6.3.14 Control/status register (RCC_CSR) */

/** Fixed clocks  */
#define STM32_SRC_HSE		0x001
#define STM32_SRC_LSE		0x002
#define STM32_SRC_LSI		0x003

/**
 * @brief STM32 clock configuration bit field.
 *
 * - reg   (1/2/3)         [ 0 : 7 ]
 * - shift (0..31)         [ 8 : 12 ]
 * - mask  (0x1, 0x3, 0x7) [ 13 : 15 ]
 * - val   (0..7)          [ 16 : 18 ]
 *
 * @param reg RCC_CCIPRx register offset
 * @param shift Position within RCC_CCIPRx.
 * @param mask Mask for the RCC_CCIPRx field.
 * @param val Clock value (0, 1, ... 7).
 */

#define STM32_CLOCK_REG_MASK    0xFFU
#define STM32_CLOCK_REG_SHIFT   0U
#define STM32_CLOCK_SHIFT_MASK  0x1FU
#define STM32_CLOCK_SHIFT_SHIFT 8U
#define STM32_CLOCK_MASK_MASK   0x7U
#define STM32_CLOCK_MASK_SHIFT  13U
#define STM32_CLOCK_VAL_MASK    0x7U
#define STM32_CLOCK_VAL_SHIFT   16U

#define STM32_CLOCK(val, mask, shift, reg)					\
	((((reg) & STM32_CLOCK_REG_MASK) << STM32_CLOCK_REG_SHIFT) |		\
	 (((shift) & STM32_CLOCK_SHIFT_MASK) << STM32_CLOCK_SHIFT_SHIFT) |	\
	 (((mask) & STM32_CLOCK_MASK_MASK) << STM32_CLOCK_MASK_SHIFT) |		\
	 (((val) & STM32_CLOCK_VAL_MASK) << STM32_CLOCK_VAL_SHIFT))

/** @brief RCC_CSR register offset */
#define CSR_REG		0x34

#define RTC_SEL(val)		STM32_CLOCK(val, 3, 16, CSR_REG)

#endif /* ZEPHYR_INCLUDE_DT_BINDINGS_CLOCK_STM32L0_CLOCK_H_ */