drivers: add snvs srtc support

core/arch/arm/plat-imx/imx-regs.h

@@ -220,11 +220,6 @@
 #define SRC_A7RCR0_A7_CORE_RESET0_OFFSET	0
 #define SRC_A7RCR1_A7_CORE1_ENABLE_OFFSET	1
 
-#define SNVS_LPCR_OFF			0x38
-#define SNVS_LPCR_TOP_MASK		BIT(6)
-#define SNVS_LPCR_DP_EN_MASK		BIT(5)
-#define SNVS_LPCR_SRTC_ENV_MASK		1
-
 #define WCR_OFF				0
 
 #define OFFSET_DIGPROG			0x260

core/drivers/imx_snvs.c

@@ -0,0 +1,185 @@
+/*
+ * Copyright 2017 NXP
+ * Copyright (c) 2014, 2015 Linaro Limited
+ *
+ * Peng Fan <peng.fan@nxp.com>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <initcall.h>
+#include <io.h>
+#include <drivers/imx_snvs.h>
+#include <kernel/misc.h>
+#include <kernel/tee_time.h>
+#include <kernel/time_source.h>
+#include <mm/core_memprot.h>
+#include <mm/core_mmu.h>
+#include <mpa.h>
+#include <utee_defines.h>
+#include <platform_config.h>
+#include <stdint.h>
+#include <tee/tee_cryp_utl.h>
+#include <types_ext.h>
+#include <trace.h>
+
+#define SNVS_LPLR	0x34
+#define SNVS_LPCR	0x38
+#define SNVS_LPMKCR	0x3C
+#define SNVS_LPSVCR	0x40
+#define SNVS_LPTGFCR	0x44
+#define SNVS_LPTDCR	0x48
+#define SNVS_LPSR	0x4C
+#define SNVS_LPSRTCMR	0x50
+#define SNVS_LPSRTCLR	0x54
+#define SNVS_LPTAR	0x58
+#define SNVS_LPSMCMR	0x5C
+#define SNVS_LPSMCLR	0x60
+#define SNVS_LPPGDR	0x64
+#define SNVS_LPGPR0_A	0x68
+#define SNVS_LPZMKR0	0x6C
+#define SNVS_LPCGR0_30	0x90
+#define SNVS_LPCGR0_31	0x94
+#define SNVS_LPCGR0_32	0x98
+#define SNVS_LPCGR0_33	0x9C
+#define SNVS_LPTDC2R	0xA0
+#define SNVS_LPTDSR	0xA4
+#define SNVS_LPTGF1CR	0xA8
+#define SNVS_LPTGF2CR	0xAC
+#define SNVS_LPAT1CR	0xC0
+#define SNVS_LPAT2CR	0xC4
+#define SNVS_LPAT3CR	0xC8
+#define SNVS_LPAT4CR	0xCC
+#define SNVS_LPAT5CR	0xD0
+#define SNVS_LPATCTLR	0xE0
+#define SNVS_LPATCLKR	0xE4
+#define SNVS_LPATRC1R	0xE8
+#define SNVS_LPATRC2R	0xEC
+
+#define SNVS_LPCR_TOP_MASK		BIT(6)
+#define SNVS_LPCR_DP_EN_MASK		BIT(5)
+#define SNVS_LPCR_SRTC_ENV_MASK		BIT(0)
+
+/* SNVS LP SRTC takes 32K clock as input */
+#define SNVS_SRTC_FREQ			0x8000
+#define CNT_TO_SECS_SHIFT		15
+#define CNT_TO_SECS_MASK		GENMASK_32(14, 0)
+
+static uint64_t snvs_srtc_read_lp_counter(void)
+{
+	vaddr_t snvs = core_mmu_get_va(SNVS_BASE, MEM_AREA_IO_SEC);
+	uint64_t val1, val2;
+	uint32_t val;
+
+	do {
+		val = read32(snvs + SNVS_LPSRTCMR);
+		val1 = val;
+		val1 <<= 32;
+		val = read32(snvs + SNVS_LPSRTCLR);
+		val1 |= val;
+
+		val = read32(snvs + SNVS_LPSRTCMR);
+		val2 = val;
+		val2 <<= 32;
+		val = read32(snvs + SNVS_LPSRTCLR);
+		val2 |= val;
+
+	/*
+	 * When cpu/bus runs at low freq, we may never get same value
+	 * during two consecutive read, so only compare the second value.
+	 */
+	} while ((val1 >> CNT_TO_SECS_SHIFT) != (val2 >> CNT_TO_SECS_SHIFT));
+
+	return val2;
+}
+
+static TEE_Result snvs_srtc_get_sys_time(TEE_Time *time)
+{
+	uint64_t cnt = snvs_srtc_read_lp_counter();
+
+	time->seconds = cnt >> CNT_TO_SECS_SHIFT;
+	time->millis = (cnt & CNT_TO_SECS_MASK) /
+		(SNVS_SRTC_FREQ / TEE_TIME_MILLIS_BASE);
+
+	return TEE_SUCCESS;
+}
+
+static const struct time_source snvs_srtc_time_source = {
+	.name = "snvs srtc",
+	.protection_level = 1000,
+	.get_sys_time = snvs_srtc_get_sys_time,
+};
+
+REGISTER_TIME_SOURCE(snvs_srtc_time_source)
+
+/* Needs to be invoked before service_init */
+TEE_Result snvs_srtc_enable(void)
+{
+	vaddr_t snvs = core_mmu_get_va(SNVS_BASE, MEM_AREA_IO_SEC);
+	int timeout = 2000;
+	uint32_t val;
+
+	val = read32(snvs + SNVS_LPCR);
+	val |= SNVS_LPCR_SRTC_ENV_MASK;
+	write32(val, snvs + SNVS_LPCR);
+
+	do {
+		val = read32(snvs + SNVS_LPCR);
+		if (val & SNVS_LPCR_SRTC_ENV_MASK)
+			break;
+	} while (--timeout);
+
+	if (!timeout)
+		return TEE_ERROR_GENERIC;
+
+	return TEE_SUCCESS;
+}
+
+/* Reused from tee_time_arm_cntpct.c */
+void plat_prng_add_jitter_entropy(void)
+{
+	uint64_t tsc = snvs_srtc_read_lp_counter();
+	int bytes = 0, n;
+	static uint8_t first, bits;
+	static uint16_t acc;
+
+	if (!first) {
+		acc = tsc;
+		bytes = 2;
+		first = 1;
+	} else {
+		acc = (acc << 2) | ((acc >> 6) & 3);
+		for (n = 0; n < 64; n += 2)
+			acc ^= (tsc >> n) & 3;
+		bits += 2;
+		if (bits >= 8) {
+			bits = 0;
+			bytes = 1;
+		}
+	}
+	if (bytes) {
+		FMSG("%s: 0x%02" PRIX16, __func__,
+		     acc & GENMASK_32(bytes * 8, 0));
+		tee_prng_add_entropy((uint8_t *)&acc, bytes);
+	}
+}

core/drivers/sub.mk

@@ -12,6 +12,7 @@ srcs-$(CFG_PL022) += pl022_spi.c
 srcs-$(CFG_SUNXI_UART) += sunxi_uart.c
 srcs-$(CFG_8250_UART) += serial8250_uart.c
 srcs-$(CFG_16550_UART) += ns16550.c
+srcs-$(CFG_IMX_SNVS) += imx_snvs.c
 srcs-$(CFG_IMX_UART) += imx_uart.c
 srcs-$(CFG_SPRD_UART) += sprd_uart.c
 srcs-$(CFG_HI16XX_UART) += hi16xx_uart.c

core/include/drivers/imx_snvs.h

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2017 NXP
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+#ifndef __DRIVERS_IMX_SNVS_H
+#define __DRIVERS_IMX_SNVS_H
+
+#include <tee_api_types.h>
+
+TEE_Result snvs_srtc_enable(void);
+
+#endif /* __DRIVERS_IMX_SNVS_H */