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5c2dd4cd7a
This driver supports the standard PWM API. There are 5 PWMs. Four are used normally and the last is normally used as a timer. Signed-off-by: Simon Glass <sjg@chromium.org> Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
136 lines
2.9 KiB
C
136 lines
2.9 KiB
C
/*
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* Copyright (C) 2009 Samsung Electronics
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* Heungjun Kim <riverful.kim@samsung.com>
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* Inki Dae <inki.dae@samsung.com>
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* Minkyu Kang <mk7.kang@samsung.com>
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <div64.h>
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#include <asm/io.h>
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#include <asm/arch/pwm.h>
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#include <asm/arch/clk.h>
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/* Use the old PWM interface for now */
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#undef CONFIG_DM_PWM
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#include <pwm.h>
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DECLARE_GLOBAL_DATA_PTR;
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unsigned long get_current_tick(void);
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/* macro to read the 16 bit timer */
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static inline struct s5p_timer *s5p_get_base_timer(void)
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{
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return (struct s5p_timer *)samsung_get_base_timer();
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}
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/**
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* Read the countdown timer.
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*
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* This operates at 1MHz and counts downwards. It will wrap about every
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* hour (2^32 microseconds).
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*
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* @return current value of timer
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*/
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static unsigned long timer_get_us_down(void)
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{
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struct s5p_timer *const timer = s5p_get_base_timer();
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return readl(&timer->tcnto4);
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}
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int timer_init(void)
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{
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/* PWM Timer 4 */
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pwm_init(4, MUX_DIV_4, 0);
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pwm_config(4, 100000, 100000);
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pwm_enable(4);
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/* Use this as the current monotonic time in us */
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gd->arch.timer_reset_value = 0;
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/* Use this as the last timer value we saw */
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gd->arch.lastinc = timer_get_us_down();
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reset_timer_masked();
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return 0;
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}
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/*
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* timer without interrupts
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*/
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unsigned long get_timer(unsigned long base)
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{
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unsigned long long time_ms;
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ulong now = timer_get_us_down();
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/*
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* Increment the time by the amount elapsed since the last read.
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* The timer may have wrapped around, but it makes no difference to
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* our arithmetic here.
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*/
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gd->arch.timer_reset_value += gd->arch.lastinc - now;
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gd->arch.lastinc = now;
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/* Divide by 1000 to convert from us to ms */
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time_ms = gd->arch.timer_reset_value;
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do_div(time_ms, 1000);
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return time_ms - base;
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}
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unsigned long __attribute__((no_instrument_function)) timer_get_us(void)
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{
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static unsigned long base_time_us;
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struct s5p_timer *const timer =
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(struct s5p_timer *)samsung_get_base_timer();
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unsigned long now_downward_us = readl(&timer->tcnto4);
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if (!base_time_us)
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base_time_us = now_downward_us;
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/* Note that this timer counts downward. */
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return base_time_us - now_downward_us;
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}
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/* delay x useconds */
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void __udelay(unsigned long usec)
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{
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unsigned long count_value;
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count_value = timer_get_us_down();
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while ((int)(count_value - timer_get_us_down()) < (int)usec)
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;
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}
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void reset_timer_masked(void)
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{
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struct s5p_timer *const timer = s5p_get_base_timer();
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/* reset time */
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gd->arch.lastinc = readl(&timer->tcnto4);
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gd->arch.tbl = 0;
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}
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/*
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* This function is derived from PowerPC code (read timebase as long long).
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* On ARM it just returns the timer value.
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*/
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unsigned long long get_ticks(void)
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{
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return get_timer(0);
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}
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/*
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* This function is derived from PowerPC code (timebase clock frequency).
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* On ARM it returns the number of timer ticks per second.
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*/
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unsigned long get_tbclk(void)
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{
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return CONFIG_SYS_HZ;
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}
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