u-boot/arch/arm/include/asm/arch-rockchip/clock.h
Simon Glass 64b7faa7f9 rockchip: clock: Add a function to find a clock by ID
The current approach of using uclass_get_device() is error-prone. Another
clock (for example a fixed-clock) may cause it to break. Add a function that
does a proper search.

Signed-off-by: Simon Glass <sjg@chromium.org>
2016-01-21 20:42:34 -07:00

77 lines
1.5 KiB
C

/*
* (C) Copyright 2015 Google, Inc
*
* SPDX-License-Identifier: GPL-2.0
*/
#ifndef _ASM_ARCH_CLOCK_H
#define _ASM_ARCH_CLOCK_H
/* define pll mode */
#define RKCLK_PLL_MODE_SLOW 0
#define RKCLK_PLL_MODE_NORMAL 1
enum {
ROCKCHIP_SYSCON_NOC,
ROCKCHIP_SYSCON_GRF,
ROCKCHIP_SYSCON_SGRF,
ROCKCHIP_SYSCON_PMU,
};
/* Standard Rockchip clock numbers */
enum rk_clk_id {
CLK_OSC,
CLK_ARM,
CLK_DDR,
CLK_CODEC,
CLK_GENERAL,
CLK_NEW,
CLK_COUNT,
};
static inline int rk_pll_id(enum rk_clk_id clk_id)
{
return clk_id - 1;
}
/**
* clk_get_divisor() - Calculate the required clock divisior
*
* Given an input rate and a required output_rate, calculate the Rockchip
* divisor needed to achieve this.
*
* @input_rate: Input clock rate in Hz
* @output_rate: Output clock rate in Hz
* @return divisor register value to use
*/
static inline u32 clk_get_divisor(ulong input_rate, uint output_rate)
{
uint clk_div;
clk_div = input_rate / output_rate;
clk_div = (clk_div + 1) & 0xfffe;
return clk_div;
}
/**
* rockchip_get_cru() - get a pointer to the clock/reset unit registers
*
* @return pointer to registers, or -ve error on error
*/
void *rockchip_get_cru(void);
/**
* rkclk_get_clk() - get a pointer to a given clock
*
* This is an internal function - use outside the clock subsystem indicates
* that work is needed!
*
* @clk_id: Clock requested
* @devp: Returns a pointer to that clock
* @return 0 if OK, -ve on error
*/
int rkclk_get_clk(enum rk_clk_id clk_id, struct udevice **devp);
#endif