1 files changed, 145 insertions, 0 deletions
diff --git a/arch/arm/mach-apple/rtkit_helper.c b/arch/arm/mach-apple/rtkit_helper.c
new file mode 100644
index 00000000000..b7d60e15700
--- /dev/null
+++ b/arch/arm/mach-apple/rtkit_helper.c
@@ -0,0 +1,145 @@
+// SPDX-License-Identifier: GPL-2.0+ OR MIT
+/*
+ * Copyright The Asahi Linux Contributors
+ */
+
+#include <dm.h>
+#include <mailbox.h>
+#include <mapmem.h>
+#include <reset.h>
+
+#include <asm/io.h>
+#include <asm/arch/rtkit.h>
+#include <linux/iopoll.h>
+
+/* ASC registers */
+#define REG_CPU_CTRL		0x0044
+#define  REG_CPU_CTRL_RUN	BIT(4)
+
+#define APPLE_RTKIT_EP_OSLOG 8
+
+struct rtkit_helper_priv {
+	void *asc;		/* ASC registers */
+	struct mbox_chan chan;
+	struct apple_rtkit *rtk;
+	bool sram_stolen;
+};
+
+static int shmem_setup(void *cookie, struct apple_rtkit_buffer *buf) {
+	struct udevice *dev = cookie;
+	struct rtkit_helper_priv *priv = dev_get_priv(dev);
+
+	if (!buf->is_mapped) {
+		/*
+		 * Special case: The OSLog buffer on MTP persists on Linux handoff.
+		 * Steal some SRAM instead of putting this in DRAM, so we don't
+		 * have to hand off DART/DAPF mappings.
+		 */
+		if (buf->endpoint == APPLE_RTKIT_EP_OSLOG) {
+			if (priv->sram_stolen) {
+				printf("%s: Tried to map more than one OSLog buffer out of SRAM\n",
+				       __func__);
+			} else {
+				fdt_size_t size;
+				fdt_addr_t addr;
+
+				addr = dev_read_addr_size_name(dev, "sram", &size);
+
+				if (addr != FDT_ADDR_T_NONE) {
+					buf->dva = ALIGN_DOWN(addr + size - buf->size, SZ_16K);
+					priv->sram_stolen = true;
+
+					return 0;
+				} else {
+					printf("%s: No SRAM, falling back to DRAM\n", __func__);
+				}
+			}
+		}
+
+		buf->buffer = memalign(SZ_16K, ALIGN(buf->size, SZ_16K));
+		if (!buf->buffer)
+			return -ENOMEM;
+
+		buf->dva = (u64)buf->buffer;
+	}
+	return 0;
+}
+
+static void shmem_destroy(void *cookie, struct apple_rtkit_buffer *buf) {
+	if (buf->buffer)
+		free(buf->buffer);
+}
+
+static int rtkit_helper_probe(struct udevice *dev)
+{
+	struct rtkit_helper_priv *priv = dev_get_priv(dev);
+	u32 ctrl;
+	int ret;
+
+	priv->asc = dev_read_addr_ptr(dev);
+	if (!priv->asc)
+		return -EINVAL;
+
+	ret = mbox_get_by_index(dev, 0, &priv->chan);
+	if (ret < 0)
+		return ret;
+
+	ctrl = readl(priv->asc + REG_CPU_CTRL);
+	writel(ctrl | REG_CPU_CTRL_RUN, priv->asc + REG_CPU_CTRL);
+
+	priv->rtk = apple_rtkit_init(&priv->chan, dev, shmem_setup, shmem_destroy);
+	if (!priv->rtk)
+		return -ENOMEM;
+
+	ret = apple_rtkit_boot(priv->rtk);
+	if (ret < 0) {
+		printf("%s: Helper apple_rtkit_boot returned: %d\n", __func__, ret);
+		return ret;
+	}
+
+	ret = apple_rtkit_set_ap_power(priv->rtk, APPLE_RTKIT_PWR_STATE_ON);
+	if (ret < 0) {
+		printf("%s: Helper apple_rtkit_set_ap_power returned: %d\n", __func__, ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int rtkit_helper_remove(struct udevice *dev)
+{
+	struct rtkit_helper_priv *priv = dev_get_priv(dev);
+	u32 ctrl;
+
+	apple_rtkit_shutdown(priv->rtk, APPLE_RTKIT_PWR_STATE_QUIESCED);
+
+	ctrl = readl(priv->asc + REG_CPU_CTRL);
+	writel(ctrl & ~REG_CPU_CTRL_RUN, priv->asc + REG_CPU_CTRL);
+
+	apple_rtkit_free(priv->rtk);
+	priv->rtk = NULL;
+
+	return 0;
+}
+
+int apple_rtkit_helper_poll(struct udevice *dev, ulong timeout)
+{
+	struct rtkit_helper_priv *priv = dev_get_priv(dev);
+
+	return apple_rtkit_poll(priv->rtk, timeout);
+}
+
+static const struct udevice_id rtkit_helper_ids[] = {
+	{ .compatible = "apple,rtk-helper-asc4" },
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(rtkit_helper) = {
+	.name = "rtkit_helper",
+	.id = UCLASS_MISC,
+	.of_match = rtkit_helper_ids,
+	.priv_auto = sizeof(struct rtkit_helper_priv),
+	.probe = rtkit_helper_probe,
+	.remove = rtkit_helper_remove,
+	.flags = DM_FLAG_OS_PREPARE,
+};