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authorDeepa Dinamani <deepad@codeaurora.org>2014-07-14 16:26:11 -0700
committerMarc Jones <marc.jones@se-eng.com>2015-03-17 16:30:58 +0100
commit74aa7770f6ec4184faff83fce3d2e843e65cf347 (patch)
tree4158be58d6fdc42916ff5b9ba0ffcad6b06dbe8b
parentf69a99dbf843da7f4c2b4965004140d2ea83cd67 (diff)
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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>
-rw-r--r--src/soc/qualcomm/ipq806x/timer.c125
1 files changed, 43 insertions, 82 deletions
diff --git a/src/soc/qualcomm/ipq806x/timer.c b/src/soc/qualcomm/ipq806x/timer.c
index 3cb9531d3..55386e949 100644
--- a/src/soc/qualcomm/ipq806x/timer.c
+++ b/src/soc/qualcomm/ipq806x/timer.c
@@ -1,8 +1,5 @@
/*
- * Copyright (c) 2012 - 2013 The Linux Foundation. All rights reserved.
- * Source : APQ8064 LK boot
- *
- * Copyright (c) 2011-2012, Code Aurora Forum. All rights reserved.
+ * Copyright (c) 2011 - 2014 The Linux Foundation. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
@@ -36,103 +33,67 @@
#include <ipq_timer.h>
#include <timer.h>
-#define GPT_FREQ_KHZ 32
-#define GPT_FREQ (GPT_FREQ_KHZ * 1000) /* 32 KHz */
+/*
+ * DGT runs at 25 MHz / 4, or 6.25 ticks per microsecond
+ */
+#define DGT_MHZ_NUM 25
+#define DGT_MHZ_DEN 4
+
+#define TIMER_TICKS(us) ((DGT_MHZ_NUM*(us) + (DGT_MHZ_DEN - 1)) / DGT_MHZ_DEN)
+#define TIMER_USECS(ticks) (DGT_MHZ_DEN*(ticks) / DGT_MHZ_NUM)
+
+/* Clock divider values for the timer. */
+#define DGT_CLK_DIV_1 0
+#define DGT_CLK_DIV_2 1
+#define DGT_CLK_DIV_3 2
+#define DGT_CLK_DIV_4 3
/**
* init_timer - initialize timer
*/
void init_timer(void)
{
- writel(0, GPT_ENABLE);
- writel(GPT_ENABLE_EN, GPT_ENABLE);
+ /* disable timer */
+ writel_i(0, DGT_ENABLE);
+
+ /* DGT uses TCXO source which is 25MHz.
+ * The timer should run at 1/4th the frequency of TCXO
+ * according to clock plan.
+ * Set clock divider to 4.
+ */
+ writel_i(DGT_CLK_DIV_4, DGT_CLK_CTL);
+
+ /* Enable timer */
+ writel_i(0, DGT_CLEAR);
+ writel_i(DGT_ENABLE_EN, DGT_ENABLE);
}
/**
* udelay - generates micro second delay.
* @param usec: delay duration in microseconds
- *
- * With 32KHz clock, minimum possible delay is 31.25 Micro seconds and
- * its multiples. In Rumi GPT clock is 32 KHz
*/
void udelay(unsigned usec)
{
- unsigned val;
- unsigned now, last;
- unsigned runcount;
+ uint32_t now;
+ uint32_t last;
+ uint32_t ticks;
+ uint32_t curr_ticks = 0;
- usec = (usec + GPT_FREQ_KHZ - 1) / GPT_FREQ_KHZ;
- last = readl(GPT_COUNT_VAL);
- runcount = last;
- val = usec + last;
+ /* Calculate number of ticks required. */
+ ticks = TIMER_TICKS(usec);
- do {
- now = readl(GPT_COUNT_VAL);
- if (last > now)
- runcount += ((GPT_FREQ - last) + now);
- else
- runcount += (now - last);
- last = now;
- } while (runcount < val);
-}
-
-void timer_monotonic_get(struct mono_time *mt)
-{
- mono_time_set_usecs(mt, (readl(GPT_COUNT_VAL) * 1000) / GPT_FREQ_KHZ);
-}
-
-#if 0
-
-/*
- * TODO(vbendeb) clean it up later.
- * Compile out the below code but leave it for now in case it will become
- * necessary later in order to make the platform fully functional.
- */
-static unsigned long timestamp;
-static unsigned long lastinc;
+ /* Obtain the current timer value. */
+ last = readl_i(DGT_COUNT_VAL);
-inline ulong gpt_to_sys_freq(unsigned int gpt)
-{
- /*
- * get_timer() expects the timer increments to be in terms
- * of CONFIG_SYS_HZ. Convert GPT timer values to CONFIG_SYS_HZ
- * units.
- */
- return (((ulong)gpt) / (GPT_FREQ / CONFIG_SYS_HZ));
-}
-
-/**
- * get_timer_masked - returns current ticks
- *
- * Returns the current timer ticks, since boot.
- */
-ulong get_timer_masked(void)
-{
- ulong now = gpt_to_sys_freq(readl(GPT_COUNT_VAL));
-
- if (lastinc <= now) { /* normal mode (non roll) */
- /* normal mode */
- timestamp += now - lastinc;
- /* move stamp forward with absolute diff ticks */
- } else { /* we have overflow of the count down timer */
- timestamp += now + (TIMER_LOAD_VAL - lastinc);
+ /* Loop until the right number of ticks. */
+ while (curr_ticks < ticks) {
+ now = readl_i(DGT_COUNT_VAL);
+ curr_ticks += now - last;
+ last = now;
}
-
- lastinc = now;
-
- return timestamp;
}
-unsigned long long get_ticks(void)
-{
- return readl(GPT_COUNT_VAL);
-}
-
-/*
- * Return the number of timer ticks per second.
- */
-ulong get_tbclk(void)
+void timer_monotonic_get(struct mono_time *mt)
{
- return GPT_FREQ;
+ mono_time_set_usecs(mt, TIMER_USECS(readl_i(DGT_COUNT_VAL)));
}
-#endif