soc/ipq806x: Replace GPT with fine grained DGT timer.
Support 1MHz libpayload restriction on timer implementation by using DGT (debug) timer instead of GPT (general purpose) timer. BUG=chrome-os-partner:28880 TEST=manual verified DGT timer functions in coreboot and depthcharge. Original-Change-Id: Iab322d7e863e3959c027e9ce876223a64eb7e257 Original-Signed-off-by: Deepa Dinamani <deepad@codeaurora.org> Original-Reviewed-on: https://chromium-review.googlesource.com/201574 Original-Reviewed-by: Vadim Bendebury <vbendeb@chromium.org> Original-Commit-Queue: Vadim Bendebury <vbendeb@chromium.org> Original-Tested-by: Vadim Bendebury <vbendeb@chromium.org> (cherry picked from commit ddf11eee5ec2d86a62095e932dbec9313b8fb9e1) Signed-off-by: Marc Jones <marc.jones@se-eng.com> Change-Id: Id73e805801fd8d135b607df9f4f8caf567ec5b83 Reviewed-on: http://review.coreboot.org/8596 Tested-by: build bot (Jenkins) Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
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Deepa Dinamani
Marc Jones
parent
f69a99dbf8
commit
74aa7770f6
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@ -1,8 +1,5 @@
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/*
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* Copyright (c) 2012 - 2013 The Linux Foundation. All rights reserved.
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* Source : APQ8064 LK boot
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*
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* Copyright (c) 2011-2012, Code Aurora Forum. All rights reserved.
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* Copyright (c) 2011 - 2014 The Linux Foundation. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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@ -36,103 +33,67 @@
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#include <ipq_timer.h>
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#include <timer.h>
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#define GPT_FREQ_KHZ 32
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#define GPT_FREQ (GPT_FREQ_KHZ * 1000) /* 32 KHz */
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/*
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* DGT runs at 25 MHz / 4, or 6.25 ticks per microsecond
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*/
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#define DGT_MHZ_NUM 25
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#define DGT_MHZ_DEN 4
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#define TIMER_TICKS(us) ((DGT_MHZ_NUM*(us) + (DGT_MHZ_DEN - 1)) / DGT_MHZ_DEN)
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#define TIMER_USECS(ticks) (DGT_MHZ_DEN*(ticks) / DGT_MHZ_NUM)
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/* Clock divider values for the timer. */
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#define DGT_CLK_DIV_1 0
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#define DGT_CLK_DIV_2 1
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#define DGT_CLK_DIV_3 2
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#define DGT_CLK_DIV_4 3
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/**
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* init_timer - initialize timer
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*/
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void init_timer(void)
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{
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writel(0, GPT_ENABLE);
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writel(GPT_ENABLE_EN, GPT_ENABLE);
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/* disable timer */
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writel_i(0, DGT_ENABLE);
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/* DGT uses TCXO source which is 25MHz.
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* The timer should run at 1/4th the frequency of TCXO
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* according to clock plan.
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* Set clock divider to 4.
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*/
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writel_i(DGT_CLK_DIV_4, DGT_CLK_CTL);
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/* Enable timer */
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writel_i(0, DGT_CLEAR);
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writel_i(DGT_ENABLE_EN, DGT_ENABLE);
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}
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/**
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* udelay - generates micro second delay.
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* @param usec: delay duration in microseconds
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*
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* With 32KHz clock, minimum possible delay is 31.25 Micro seconds and
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* its multiples. In Rumi GPT clock is 32 KHz
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*/
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void udelay(unsigned usec)
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{
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unsigned val;
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unsigned now, last;
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unsigned runcount;
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uint32_t now;
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uint32_t last;
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uint32_t ticks;
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uint32_t curr_ticks = 0;
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usec = (usec + GPT_FREQ_KHZ - 1) / GPT_FREQ_KHZ;
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last = readl(GPT_COUNT_VAL);
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runcount = last;
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val = usec + last;
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/* Calculate number of ticks required. */
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ticks = TIMER_TICKS(usec);
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do {
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now = readl(GPT_COUNT_VAL);
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if (last > now)
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runcount += ((GPT_FREQ - last) + now);
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else
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runcount += (now - last);
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/* Obtain the current timer value. */
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last = readl_i(DGT_COUNT_VAL);
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/* Loop until the right number of ticks. */
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while (curr_ticks < ticks) {
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now = readl_i(DGT_COUNT_VAL);
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curr_ticks += now - last;
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last = now;
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} while (runcount < val);
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}
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}
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void timer_monotonic_get(struct mono_time *mt)
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{
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mono_time_set_usecs(mt, (readl(GPT_COUNT_VAL) * 1000) / GPT_FREQ_KHZ);
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mono_time_set_usecs(mt, TIMER_USECS(readl_i(DGT_COUNT_VAL)));
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}
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#if 0
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/*
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* TODO(vbendeb) clean it up later.
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* Compile out the below code but leave it for now in case it will become
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* necessary later in order to make the platform fully functional.
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*/
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static unsigned long timestamp;
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static unsigned long lastinc;
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inline ulong gpt_to_sys_freq(unsigned int gpt)
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{
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/*
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* get_timer() expects the timer increments to be in terms
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* of CONFIG_SYS_HZ. Convert GPT timer values to CONFIG_SYS_HZ
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* units.
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*/
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return (((ulong)gpt) / (GPT_FREQ / CONFIG_SYS_HZ));
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}
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/**
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* get_timer_masked - returns current ticks
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*
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* Returns the current timer ticks, since boot.
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*/
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ulong get_timer_masked(void)
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{
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ulong now = gpt_to_sys_freq(readl(GPT_COUNT_VAL));
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if (lastinc <= now) { /* normal mode (non roll) */
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/* normal mode */
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timestamp += now - lastinc;
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/* move stamp forward with absolute diff ticks */
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} else { /* we have overflow of the count down timer */
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timestamp += now + (TIMER_LOAD_VAL - lastinc);
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}
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lastinc = now;
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return timestamp;
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}
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unsigned long long get_ticks(void)
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{
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return readl(GPT_COUNT_VAL);
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}
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/*
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* Return the number of timer ticks per second.
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*/
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ulong get_tbclk(void)
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{
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return GPT_FREQ;
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}
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#endif
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