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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:13:47 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:13:47 +0000
commit102b0d2daa97dae68d3eed54d8fe37a9cc38a892 (patch)
treebcf648efac40ca6139842707f0eba5a4496a6dd2 /drivers/delay_timer
parentInitial commit. (diff)
downloadarm-trusted-firmware-upstream.tar.xz
arm-trusted-firmware-upstream.zip
Adding upstream version 2.8.0+dfsg.upstream/2.8.0+dfsgupstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r--drivers/delay_timer/delay_timer.c82
-rw-r--r--drivers/delay_timer/generic_delay_timer.c62
2 files changed, 144 insertions, 0 deletions
diff --git a/drivers/delay_timer/delay_timer.c b/drivers/delay_timer/delay_timer.c
new file mode 100644
index 0000000..a3fd7bf
--- /dev/null
+++ b/drivers/delay_timer/delay_timer.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2015-2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+
+#include <platform_def.h>
+
+#include <drivers/delay_timer.h>
+#include <lib/utils_def.h>
+
+/***********************************************************
+ * The delay timer implementation
+ ***********************************************************/
+static const timer_ops_t *timer_ops;
+
+/***********************************************************
+ * Delay for the given number of microseconds. The driver must
+ * be initialized before calling this function.
+ ***********************************************************/
+void udelay(uint32_t usec)
+{
+ assert((timer_ops != NULL) &&
+ (timer_ops->clk_mult != 0U) &&
+ (timer_ops->clk_div != 0U) &&
+ (timer_ops->get_timer_value != NULL));
+
+ uint32_t start, delta;
+ uint64_t total_delta;
+
+ assert(usec < (UINT64_MAX / timer_ops->clk_div));
+
+ start = timer_ops->get_timer_value();
+
+ /* Add an extra tick to avoid delaying less than requested. */
+ total_delta =
+ div_round_up((uint64_t)usec * timer_ops->clk_div,
+ timer_ops->clk_mult) + 1U;
+ /*
+ * Precaution for the total_delta ~ UINT32_MAX and the fact that we
+ * cannot catch every tick of the timer.
+ * For example 100MHz timer over 25MHz APB will miss at least 4 ticks.
+ * 1000U is an arbitrary big number which is believed to be sufficient.
+ */
+ assert(total_delta < (UINT32_MAX - 1000U));
+
+ do {
+ /*
+ * If the timer value wraps around, the subtraction will
+ * overflow and it will still give the correct result.
+ * delta is decreasing counter
+ */
+ delta = start - timer_ops->get_timer_value();
+
+ } while (delta < total_delta);
+}
+
+/***********************************************************
+ * Delay for the given number of milliseconds. The driver must
+ * be initialized before calling this function.
+ ***********************************************************/
+void mdelay(uint32_t msec)
+{
+ assert((msec * 1000UL) < UINT32_MAX);
+ udelay(msec * 1000U);
+}
+
+/***********************************************************
+ * Initialize the timer. The fields in the provided timer
+ * ops pointer must be valid.
+ ***********************************************************/
+void timer_init(const timer_ops_t *ops_ptr)
+{
+ assert((ops_ptr != NULL) &&
+ (ops_ptr->clk_mult != 0U) &&
+ (ops_ptr->clk_div != 0U) &&
+ (ops_ptr->get_timer_value != NULL));
+
+ timer_ops = ops_ptr;
+}
diff --git a/drivers/delay_timer/generic_delay_timer.c b/drivers/delay_timer/generic_delay_timer.c
new file mode 100644
index 0000000..ca522e0
--- /dev/null
+++ b/drivers/delay_timer/generic_delay_timer.c
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2016-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2020, NVIDIA Corporation. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+
+#include <arch_features.h>
+#include <arch_helpers.h>
+#include <common/bl_common.h>
+#include <common/debug.h>
+#include <drivers/delay_timer.h>
+#include <drivers/generic_delay_timer.h>
+#include <lib/utils_def.h>
+#include <plat/common/platform.h>
+
+static timer_ops_t ops;
+
+static uint32_t get_timer_value(void)
+{
+ /*
+ * Generic delay timer implementation expects the timer to be a down
+ * counter. We apply bitwise NOT operator to the tick values returned
+ * by read_cntpct_el0() to simulate the down counter. The value is
+ * clipped from 64 to 32 bits.
+ */
+ return (uint32_t)(~read_cntpct_el0());
+}
+
+void generic_delay_timer_init_args(uint32_t mult, uint32_t div)
+{
+ ops.get_timer_value = get_timer_value;
+ ops.clk_mult = mult;
+ ops.clk_div = div;
+
+ timer_init(&ops);
+
+ VERBOSE("Generic delay timer configured with mult=%u and div=%u\n",
+ mult, div);
+}
+
+void generic_delay_timer_init(void)
+{
+ assert(is_armv7_gentimer_present());
+
+ /* Value in ticks */
+ unsigned int mult = MHZ_TICKS_PER_SEC;
+
+ /* Value in ticks per second (Hz) */
+ unsigned int div = plat_get_syscnt_freq2();
+
+ /* Reduce multiplier and divider by dividing them repeatedly by 10 */
+ while (((mult % 10U) == 0U) && ((div % 10U) == 0U)) {
+ mult /= 10U;
+ div /= 10U;
+ }
+
+ generic_delay_timer_init_args(mult, div);
+}
+