NXP: Timer API added to enable ARM generic timer

NXP Timer Apis are based on:
- drivers/delay_timer
Signed-off-by: Pankaj Gupta <pankaj.gupta@nxp.com>
Change-Id: I2cbccf4c082a10affee1143390905b9cc99c3382

drivers/nxp/timer/nxp_timer.c

+/*
+ * Copyright 2021 NXP
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#include <arch_helpers.h>
+#include <common/debug.h>
+#include <drivers/delay_timer.h>
+#include <lib/mmio.h>
+#include <lib/utils_def.h>
+#include <nxp_timer.h>
+#include <plat/common/platform.h>
+
+static uintptr_t g_nxp_timer_addr;
+static timer_ops_t ops;
+
+uint64_t get_timer_val(uint64_t start)
+{
+	uint64_t cntpct;
+
+	isb();
+	cntpct = read_cntpct_el0();
+	return (cntpct * 1000ULL / read_cntfrq_el0() - start);
+}
+
+static uint32_t timer_get_value(void)
+{
+	uint64_t cntpct;
+
+	isb();
+	cntpct = read_cntpct_el0();
+#ifdef ERRATA_SOC_A008585
+	uint8_t	max_fetch_count = 10U;
+	/* This erratum number needs to be confirmed to match ARM document */
+	uint64_t temp;
+
+	isb();
+	temp = read_cntpct_el0();
+
+	while (temp != cntpct && max_fetch_count) {
+		isb();
+		cntpct = read_cntpct_el0();
+		isb();
+		temp = read_cntpct_el0();
+		max_fetch_count--;
+	}
+#endif
+
+	/*
+	 * 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)(~cntpct);
+}
+
+static void delay_timer_init_args(uint32_t mult, uint32_t div)
+{
+	ops.get_timer_value	= timer_get_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);
+}
+
+/*
+ * Initialise the nxp on-chip free rolling usec counter as the delay
+ * timer.
+ */
+void delay_timer_init(uintptr_t nxp_timer_addr)
+{
+	/* Value in ticks */
+	unsigned int mult = MHZ_TICKS_PER_SEC;
+
+	unsigned int div;
+
+	unsigned int counter_base_frequency = plat_get_syscnt_freq2();
+
+	g_nxp_timer_addr = nxp_timer_addr;
+	/* Rounding off the Counter Frequency to MHZ_TICKS_PER_SEC */
+	if (counter_base_frequency > MHZ_TICKS_PER_SEC) {
+		counter_base_frequency = (counter_base_frequency
+					/ MHZ_TICKS_PER_SEC)
+					* MHZ_TICKS_PER_SEC;
+	} else {
+		counter_base_frequency = (counter_base_frequency
+					/ KHZ_TICKS_PER_SEC)
+					* KHZ_TICKS_PER_SEC;
+	}
+
+	/* Value in ticks per second (Hz) */
+	div = counter_base_frequency;
+
+	/* Reduce multiplier and divider by dividing them repeatedly by 10 */
+	while ((mult % 10U == 0U) && (div % 10U == 0U)) {
+		mult /= 10U;
+		div /= 10U;
+	}
+
+	/* Enable and initialize the System level generic timer */
+	mmio_write_32(g_nxp_timer_addr + CNTCR_OFF,
+			CNTCR_FCREQ(0) | CNTCR_EN);
+
+	delay_timer_init_args(mult, div);
+}
+
+
+#ifdef IMAGE_BL31
+/*******************************************************************************
+ * TBD: Configures access to the system counter timer module.
+ ******************************************************************************/
+void ls_configure_sys_timer(uintptr_t ls_sys_timctl_base,
+			    uint8_t ls_config_cntacr,
+			    uint8_t plat_ls_ns_timer_frame_id)
+{
+	unsigned int reg_val;
+
+	if (ls_config_cntacr == 1U) {
+		reg_val = (1U << CNTACR_RPCT_SHIFT) | (1U << CNTACR_RVCT_SHIFT);
+		reg_val |= (1U << CNTACR_RFRQ_SHIFT) | (1U << CNTACR_RVOFF_SHIFT);
+		reg_val |= (1U << CNTACR_RWVT_SHIFT) | (1U << CNTACR_RWPT_SHIFT);
+		mmio_write_32(ls_sys_timctl_base +
+		      CNTACR_BASE(plat_ls_ns_timer_frame_id), reg_val);
+		mmio_write_32(ls_sys_timctl_base, plat_get_syscnt_freq2());
+	}
+
+	reg_val = (1U << CNTNSAR_NS_SHIFT(plat_ls_ns_timer_frame_id));
+	mmio_write_32(ls_sys_timctl_base + CNTNSAR, reg_val);
+}
+
+void enable_init_timer(void)
+{
+	/* Enable and initialize the System level generic timer */
+	mmio_write_32(g_nxp_timer_addr + CNTCR_OFF,
+			CNTCR_FCREQ(0) | CNTCR_EN);
+}
+#endif

drivers/nxp/timer/nxp_timer.h

+/*
+ * Copyright 2021 NXP
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ *
+ */
+
+#
+#ifndef NXP_TIMER_H
+#define NXP_TIMER_H
+
+ /* System Counter Offset and Bit Mask */
+#define SYS_COUNTER_CNTCR_OFFSET	0x0
+#define SYS_COUNTER_CNTCR_EN		0x00000001
+#define CNTCR_EN_MASK			0x1
+
+#ifndef __ASSEMBLER__
+uint64_t get_timer_val(uint64_t start);
+
+#ifdef IMAGE_BL31
+void ls_configure_sys_timer(uintptr_t ls_sys_timctl_base,
+			    uint8_t ls_config_cntacr,
+			    uint8_t plat_ls_ns_timer_frame_id);
+void enable_init_timer(void);
+#endif
+
+/*
+ * Initialise the nxp on-chip free rolling usec counter as the delay
+ * timer.
+ */
+void delay_timer_init(uintptr_t nxp_timer_addr);
+void ls_bl31_timer_init(uintptr_t nxp_timer_addr);
+#endif	/* __ASSEMBLER__ */
+
+#endif /* NXP_TIMER_H */

drivers/nxp/timer/timer.mk

+#
+# Copyright 2021 NXP
+#
+# SPDX-License-Identifier: BSD-3-Clause
+#
+
+ifeq (${ADD_TIMER},)
+
+ADD_TIMER		:= 1
+
+TIMER_DRIVERS_PATH	:=  ${PLAT_DRIVERS_PATH}/timer
+
+PLAT_INCLUDES		+= -I$(TIMER_DRIVERS_PATH)
+TIMER_SOURCES	+= drivers/delay_timer/delay_timer.c	\
+			   $(PLAT_DRIVERS_PATH)/timer/nxp_timer.c
+
+ifeq (${BL_COMM_TIMER_NEEDED},yes)
+BL_COMMON_SOURCES	+= ${TIMER_SOURCES}
+else
+ifeq (${BL2_TIMER_NEEDED},yes)
+BL2_SOURCES		+= ${TIMER_SOURCES}
+endif
+ifeq (${BL31_TIMER_NEEDED},yes)
+BL31_SOURCES		+= ${TIMER_SOURCES}
+endif
+endif
+endif

include/lib/utils_def.h

@@ -163,4 +163,9 @@
  */
 #define MHZ_TICKS_PER_SEC	U(1000000)
 
+/*
+ * Ticks elapsed in one second with a signal of 1 KHz
+ */
+#define KHZ_TICKS_PER_SEC U(1000)
+
 #endif /* UTILS_DEF_H */