Tegra210: bpmp: power management interface
This patch adds the driver to communicate with the BPMP processor
for power management use cases. BPMP controls the entry into cluster
and system power states. The Tegra210 platform port queries the BPMP
to calculate the target state for the cluster. In case BPMP does not
allow CCx entry, the core enters a power down state.
Change-Id: I9c40aef561607a0b02c49b7f8118570eb9105cc9
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>
diff --git a/plat/nvidia/tegra/common/drivers/bpmp/bpmp.c b/plat/nvidia/tegra/common/drivers/bpmp/bpmp.c
new file mode 100644
index 0000000..c78b912
--- /dev/null
+++ b/plat/nvidia/tegra/common/drivers/bpmp/bpmp.c
@@ -0,0 +1,173 @@
+/*
+ * Copyright (c) 2017, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <arch_helpers.h>
+#include <assert.h>
+#include <bpmp.h>
+#include <common/debug.h>
+#include <delay_timer.h>
+#include <errno.h>
+#include <mmio.h>
+#include <platform.h>
+#include <stdbool.h>
+#include <string.h>
+#include <tegra_def.h>
+
+#define BPMP_TIMEOUT_10US 10
+
+static uint32_t channel_base[NR_CHANNELS];
+static uint32_t bpmp_init_state = BPMP_INIT_PENDING;
+
+static uint32_t channel_field(unsigned int ch)
+{
+ return mmio_read_32(TEGRA_RES_SEMA_BASE + STA_OFFSET) & CH_MASK(ch);
+}
+
+static bool master_free(unsigned int ch)
+{
+ return channel_field(ch) == MA_FREE(ch);
+}
+
+static bool master_acked(unsigned int ch)
+{
+ return channel_field(ch) == MA_ACKD(ch);
+}
+
+static void signal_slave(unsigned int ch)
+{
+ mmio_write_32(TEGRA_RES_SEMA_BASE + CLR_OFFSET, CH_MASK(ch));
+}
+
+static void free_master(unsigned int ch)
+{
+ mmio_write_32(TEGRA_RES_SEMA_BASE + CLR_OFFSET,
+ MA_ACKD(ch) ^ MA_FREE(ch));
+}
+
+/* should be called with local irqs disabled */
+int32_t tegra_bpmp_send_receive_atomic(int mrq, const void *ob_data, int ob_sz,
+ void *ib_data, int ib_sz)
+{
+ unsigned int ch = (unsigned int)plat_my_core_pos();
+ mb_data_t *p = (mb_data_t *)(uintptr_t)channel_base[ch];
+ int32_t ret = -ETIMEDOUT, timeout = 0;
+
+ if (bpmp_init_state == BPMP_INIT_COMPLETE) {
+
+ /* loop until BPMP is free */
+ for (timeout = 0; timeout < BPMP_TIMEOUT_10US; timeout++) {
+ if (master_free(ch) == true) {
+ break;
+ }
+
+ udelay(1);
+ }
+
+ if (timeout != BPMP_TIMEOUT_10US) {
+
+ /* generate the command struct */
+ p->code = mrq;
+ p->flags = DO_ACK;
+ (void)memcpy((void *)p->data, ob_data, (size_t)ob_sz);
+
+ /* signal command ready to the BPMP */
+ signal_slave(ch);
+ mmio_write_32(TEGRA_PRI_ICTLR_BASE + CPU_IEP_FIR_SET,
+ (1UL << INT_SHR_SEM_OUTBOX_FULL));
+
+ /* loop until the command is executed */
+ for (timeout = 0; timeout < BPMP_TIMEOUT_10US; timeout++) {
+ if (master_acked(ch) == true) {
+ break;
+ }
+
+ udelay(1);
+ }
+
+ if (timeout != BPMP_TIMEOUT_10US) {
+
+ /* get the command response */
+ (void)memcpy(ib_data, (const void *)p->data,
+ (size_t)ib_sz);
+
+ /* return error code */
+ ret = p->code;
+
+ /* free this channel */
+ free_master(ch);
+ }
+ }
+
+ } else {
+ /* return error code */
+ ret = -EINVAL;
+ }
+
+ if (timeout == BPMP_TIMEOUT_10US) {
+ ERROR("Timed out waiting for bpmp's response");
+ }
+
+ return ret;
+}
+
+int tegra_bpmp_init(void)
+{
+ uint32_t val, base;
+ unsigned int ch;
+ int ret = 0;
+
+ if (bpmp_init_state != BPMP_INIT_COMPLETE) {
+
+ /* check if the bpmp processor is alive. */
+ val = mmio_read_32(TEGRA_RES_SEMA_BASE + STA_OFFSET);
+ if (val != SIGN_OF_LIFE) {
+ ERROR("BPMP precessor not available\n");
+ ret = -ENOTSUP;
+ }
+
+ /* check if clock for the atomics block is enabled */
+ val = mmio_read_32(TEGRA_CAR_RESET_BASE + TEGRA_CLK_ENB_V);
+ if ((val & CAR_ENABLE_ATOMICS) == 0) {
+ ERROR("Clock to the atomics block is disabled\n");
+ }
+
+ /* check if the atomics block is out of reset */
+ val = mmio_read_32(TEGRA_CAR_RESET_BASE + TEGRA_RST_DEV_CLR_V);
+ if ((val & CAR_ENABLE_ATOMICS) == 0) {
+ ERROR("Reset to the atomics block is asserted\n");
+ }
+
+ /* base address to get the result from Atomics */
+ base = TEGRA_ATOMICS_BASE + RESULT0_REG_OFFSET;
+
+ /* channel area is setup by BPMP before signaling handshake */
+ for (ch = 0; ch < NR_CHANNELS; ch++) {
+
+ /* issue command to get the channel base address */
+ mmio_write_32(base, (ch << TRIGGER_ID_SHIFT) |
+ ATOMIC_CMD_GET);
+
+ /* get the base address for the channel */
+ channel_base[ch] = mmio_read_32(base);
+
+ /* increment result register offset */
+ base += 4UL;
+ }
+
+ /* mark state as "initialized" */
+ if (ret == 0)
+ bpmp_init_state = BPMP_INIT_COMPLETE;
+
+ /* the channel values have to be visible across all cpus */
+ flush_dcache_range((uint64_t)channel_base, sizeof(channel_base));
+ flush_dcache_range((uint64_t)&bpmp_init_state,
+ sizeof(bpmp_init_state));
+
+ INFO("%s: done\n", __func__);
+ }
+
+ return ret;
+}