1 files changed, 253 insertions, 0 deletions
diff --git a/drivers/mfd/loongson-se.c b/drivers/mfd/loongson-se.c
new file mode 100644
index 000000000000..3902ba377d69
--- /dev/null
+++ b/drivers/mfd/loongson-se.c
@@ -0,0 +1,253 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2025 Loongson Technology Corporation Limited
+ *
+ * Author: Yinggang Gu <guyinggang@loongson.cn>
+ * Author: Qunqin Zhao <zhaoqunqin@loongson.cn>
+ */
+
+#include <linux/acpi.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/dma-mapping.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/loongson-se.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+
+struct loongson_se {
+	void __iomem *base;
+	spinlock_t dev_lock;
+	struct completion cmd_completion;
+
+	void *dmam_base;
+	int dmam_size;
+
+	struct mutex engine_init_lock;
+	struct loongson_se_engine engines[SE_ENGINE_MAX];
+};
+
+struct loongson_se_controller_cmd {
+	u32 command_id;
+	u32 info[7];
+};
+
+static int loongson_se_poll(struct loongson_se *se, u32 int_bit)
+{
+	u32 status;
+	int err;
+
+	spin_lock_irq(&se->dev_lock);
+
+	/* Notify the controller that the engine needs to be started */
+	writel(int_bit, se->base + SE_L2SINT_SET);
+
+	/* Polling until the controller has forwarded the engine command */
+	err = readl_relaxed_poll_timeout_atomic(se->base + SE_L2SINT_STAT, status,
+						!(status & int_bit),
+						1, LOONGSON_ENGINE_CMD_TIMEOUT_US);
+
+	spin_unlock_irq(&se->dev_lock);
+
+	return err;
+}
+
+static int loongson_se_send_controller_cmd(struct loongson_se *se,
+					   struct loongson_se_controller_cmd *cmd)
+{
+	u32 *send_cmd = (u32 *)cmd;
+	int err, i;
+
+	for (i = 0; i < SE_SEND_CMD_REG_LEN; i++)
+		writel(send_cmd[i], se->base + SE_SEND_CMD_REG + i * 4);
+
+	err = loongson_se_poll(se, SE_INT_CONTROLLER);
+	if (err)
+		return err;
+
+	return wait_for_completion_interruptible(&se->cmd_completion);
+}
+
+int loongson_se_send_engine_cmd(struct loongson_se_engine *engine)
+{
+	/*
+	 * After engine initialization, the controller already knows
+	 * where to obtain engine commands from. Now all we need to
+	 * do is notify the controller that the engine needs to be started.
+	 */
+	int err = loongson_se_poll(engine->se, BIT(engine->id));
+
+	if (err)
+		return err;
+
+	return wait_for_completion_interruptible(&engine->completion);
+}
+EXPORT_SYMBOL_GPL(loongson_se_send_engine_cmd);
+
+struct loongson_se_engine *loongson_se_init_engine(struct device *dev, int id)
+{
+	struct loongson_se *se = dev_get_drvdata(dev);
+	struct loongson_se_engine *engine = &se->engines[id];
+	struct loongson_se_controller_cmd cmd;
+
+	engine->se = se;
+	engine->id = id;
+	init_completion(&engine->completion);
+
+	/* Divide DMA memory equally among all engines */
+	engine->buffer_size = se->dmam_size / SE_ENGINE_MAX;
+	engine->buffer_off = (se->dmam_size / SE_ENGINE_MAX) * id;
+	engine->data_buffer = se->dmam_base + engine->buffer_off;
+
+	/*
+	 * There has no engine0, use its data buffer as command buffer for other
+	 * engines. The DMA memory size is obtained from the ACPI table, which
+	 * ensures that the data buffer size of engine0 is larger than the
+	 * command buffer size of all engines.
+	 */
+	engine->command = se->dmam_base + id * (2 * SE_ENGINE_CMD_SIZE);
+	engine->command_ret = engine->command + SE_ENGINE_CMD_SIZE;
+
+	mutex_lock(&se->engine_init_lock);
+
+	/* Tell the controller where to find engine command */
+	cmd.command_id = SE_CMD_SET_ENGINE_CMDBUF;
+	cmd.info[0] = id;
+	cmd.info[1] = engine->command - se->dmam_base;
+	cmd.info[2] = 2 * SE_ENGINE_CMD_SIZE;
+
+	if (loongson_se_send_controller_cmd(se, &cmd))
+		engine = NULL;
+
+	mutex_unlock(&se->engine_init_lock);
+
+	return engine;
+}
+EXPORT_SYMBOL_GPL(loongson_se_init_engine);
+
+static irqreturn_t se_irq_handler(int irq, void *dev_id)
+{
+	struct loongson_se *se = dev_id;
+	u32 int_status;
+	int id;
+
+	spin_lock(&se->dev_lock);
+
+	int_status = readl(se->base + SE_S2LINT_STAT);
+
+	/* For controller */
+	if (int_status & SE_INT_CONTROLLER) {
+		complete(&se->cmd_completion);
+		int_status &= ~SE_INT_CONTROLLER;
+		writel(SE_INT_CONTROLLER, se->base + SE_S2LINT_CL);
+	}
+
+	/* For engines */
+	while (int_status) {
+		id = __ffs(int_status);
+		complete(&se->engines[id].completion);
+		int_status &= ~BIT(id);
+		writel(BIT(id), se->base + SE_S2LINT_CL);
+	}
+
+	spin_unlock(&se->dev_lock);
+
+	return IRQ_HANDLED;
+}
+
+static int loongson_se_init(struct loongson_se *se, dma_addr_t addr, int size)
+{
+	struct loongson_se_controller_cmd cmd;
+	int err;
+
+	cmd.command_id = SE_CMD_START;
+	err = loongson_se_send_controller_cmd(se, &cmd);
+	if (err)
+		return err;
+
+	cmd.command_id = SE_CMD_SET_DMA;
+	cmd.info[0] = lower_32_bits(addr);
+	cmd.info[1] = upper_32_bits(addr);
+	cmd.info[2] = size;
+
+	return loongson_se_send_controller_cmd(se, &cmd);
+}
+
+static const struct mfd_cell engines[] = {
+	{ .name = "loongson-rng" },
+	{ .name = "tpm_loongson" },
+};
+
+static int loongson_se_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct loongson_se *se;
+	int nr_irq, irq, err, i;
+	dma_addr_t paddr;
+
+	se = devm_kmalloc(dev, sizeof(*se), GFP_KERNEL);
+	if (!se)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, se);
+	init_completion(&se->cmd_completion);
+	spin_lock_init(&se->dev_lock);
+	mutex_init(&se->engine_init_lock);
+
+	dma_set_mask_and_coherent(dev, DMA_BIT_MASK(64));
+	if (device_property_read_u32(dev, "dmam_size", &se->dmam_size))
+		return -ENODEV;
+
+	se->dmam_base = dmam_alloc_coherent(dev, se->dmam_size, &paddr, GFP_KERNEL);
+	if (!se->dmam_base)
+		return -ENOMEM;
+
+	se->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(se->base))
+		return PTR_ERR(se->base);
+
+	writel(SE_INT_ALL, se->base + SE_S2LINT_EN);
+
+	nr_irq = platform_irq_count(pdev);
+	if (nr_irq <= 0)
+		return -ENODEV;
+
+	for (i = 0; i < nr_irq; i++) {
+		irq = platform_get_irq(pdev, i);
+		err = devm_request_irq(dev, irq, se_irq_handler, 0, "loongson-se", se);
+		if (err)
+			dev_err(dev, "failed to request IRQ: %d\n", irq);
+	}
+
+	err = loongson_se_init(se, paddr, se->dmam_size);
+	if (err)
+		return err;
+
+	return devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE, engines,
+				    ARRAY_SIZE(engines), NULL, 0, NULL);
+}
+
+static const struct acpi_device_id loongson_se_acpi_match[] = {
+	{ "LOON0011", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(acpi, loongson_se_acpi_match);
+
+static struct platform_driver loongson_se_driver = {
+	.probe   = loongson_se_probe,
+	.driver  = {
+		.name  = "loongson-se",
+		.acpi_match_table = loongson_se_acpi_match,
+	},
+};
+module_platform_driver(loongson_se_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Yinggang Gu <guyinggang@loongson.cn>");
+MODULE_AUTHOR("Qunqin Zhao <zhaoqunqin@loongson.cn>");
+MODULE_DESCRIPTION("Loongson Security Engine chip controller driver");