peci: Add Aspeed PECI adapter driver

This commit adds Aspeed PECI adapter driver for Aspeed
AST24xx/25xx/26xx SoCs.

Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Reviewed-by: Haiyue Wang <haiyue.wang@linux.intel.com>
Reviewed-by: James Feist <james.feist@linux.intel.com>
Reviewed-by: Vernon Mauery <vernon.mauery@linux.intel.com>

3 files changed, 500 insertions, 0 deletions

diff --git a/drivers/peci/busses/Kconfig b/drivers/peci/busses/Kconfig
index d7e064f52a1c..ba0b05b29100 100644
--- a/drivers/peci/busses/Kconfig
+++ b/drivers/peci/busses/Kconfig
@@ -4,4 +4,17 @@
 
 menu "PECI Hardware Bus support"
 
+config PECI_ASPEED
+	tristate "ASPEED PECI support"
+	depends on ARCH_ASPEED || COMPILE_TEST
+	depends on OF
+	depends on HAS_IOMEM
+	depends on PECI
+	help
+	  Say Y here if you want support for the Platform Environment Control
+	  Interface (PECI) bus adapter driver on the ASPEED SoCs.
+
+	  This support is also available as a module. If so, the module
+	  will be called peci-aspeed.
+
 endmenu
diff --git a/drivers/peci/busses/Makefile b/drivers/peci/busses/Makefile
index 9e9334fee297..69e31dfaca19 100644
--- a/drivers/peci/busses/Makefile
+++ b/drivers/peci/busses/Makefile
@@ -2,3 +2,5 @@
 #
 # Makefile for the PECI hardware bus drivers.
 #
+
+obj-$(CONFIG_PECI_ASPEED)	+= peci-aspeed.o
diff --git a/drivers/peci/busses/peci-aspeed.c b/drivers/peci/busses/peci-aspeed.c
new file mode 100644
index 000000000000..b6ccef550c0a
--- /dev/null
+++ b/drivers/peci/busses/peci-aspeed.c
@@ -0,0 +1,485 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2012-2017 ASPEED Technology Inc.
+// Copyright (c) 2018-2019 Intel Corporation
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/peci.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+
+/* ASPEED PECI Registers */
+/* Control Register */
+#define ASPEED_PECI_CTRL			0x00
+#define   ASPEED_PECI_CTRL_SAMPLING_MASK	GENMASK(19, 16)
+#define   ASPEED_PECI_CTRL_READ_MODE_MASK	GENMASK(13, 12)
+#define   ASPEED_PECI_CTRL_READ_MODE_COUNT	BIT(12)
+#define   ASPEED_PECI_CTRL_READ_MODE_DBG	BIT(13)
+#define   ASPEED_PECI_CTRL_CLK_SOURCE_MASK	BIT(11)
+#define   ASPEED_PECI_CTRL_CLK_DIV_MASK		GENMASK(10, 8)
+#define   ASPEED_PECI_CTRL_INVERT_OUT		BIT(7)
+#define   ASPEED_PECI_CTRL_INVERT_IN		BIT(6)
+#define   ASPEED_PECI_CTRL_BUS_CONTENT_EN	BIT(5)
+#define   ASPEED_PECI_CTRL_PECI_EN		BIT(4)
+#define   ASPEED_PECI_CTRL_PECI_CLK_EN		BIT(0)
+
+/* Timing Negotiation Register */
+#define ASPEED_PECI_TIMING_NEGOTIATION		0x04
+#define   ASPEED_PECI_TIMING_MESSAGE_MASK	GENMASK(15, 8)
+#define   ASPEED_PECI_TIMING_ADDRESS_MASK	GENMASK(7, 0)
+
+/* Command Register */
+#define ASPEED_PECI_CMD				0x08
+#define   ASPEED_PECI_CMD_PIN_MON		BIT(31)
+#define   ASPEED_PECI_CMD_STS_MASK		GENMASK(27, 24)
+#define   ASPEED_PECI_CMD_IDLE_MASK		\
+	  (ASPEED_PECI_CMD_STS_MASK | ASPEED_PECI_CMD_PIN_MON)
+#define   ASPEED_PECI_CMD_FIRE			BIT(0)
+
+/* Read/Write Length Register */
+#define ASPEED_PECI_RW_LENGTH			0x0c
+#define   ASPEED_PECI_AW_FCS_EN			BIT(31)
+#define   ASPEED_PECI_READ_LEN_MASK		GENMASK(23, 16)
+#define   ASPEED_PECI_WRITE_LEN_MASK		GENMASK(15, 8)
+#define   ASPEED_PECI_TAGET_ADDR_MASK		GENMASK(7, 0)
+
+/* Expected FCS Data Register */
+#define ASPEED_PECI_EXP_FCS			0x10
+#define   ASPEED_PECI_EXP_READ_FCS_MASK		GENMASK(23, 16)
+#define   ASPEED_PECI_EXP_AW_FCS_AUTO_MASK	GENMASK(15, 8)
+#define   ASPEED_PECI_EXP_WRITE_FCS_MASK	GENMASK(7, 0)
+
+/* Captured FCS Data Register */
+#define ASPEED_PECI_CAP_FCS			0x14
+#define   ASPEED_PECI_CAP_READ_FCS_MASK		GENMASK(23, 16)
+#define   ASPEED_PECI_CAP_WRITE_FCS_MASK	GENMASK(7, 0)
+
+/* Interrupt Register */
+#define ASPEED_PECI_INT_CTRL			0x18
+#define   ASPEED_PECI_TIMING_NEGO_SEL_MASK	GENMASK(31, 30)
+#define     ASPEED_PECI_1ST_BIT_OF_ADDR_NEGO	0
+#define     ASPEED_PECI_2ND_BIT_OF_ADDR_NEGO	1
+#define     ASPEED_PECI_MESSAGE_NEGO		2
+#define   ASPEED_PECI_INT_MASK			GENMASK(4, 0)
+#define   ASPEED_PECI_INT_BUS_TIMEOUT		BIT(4)
+#define   ASPEED_PECI_INT_BUS_CONNECT		BIT(3)
+#define   ASPEED_PECI_INT_W_FCS_BAD		BIT(2)
+#define   ASPEED_PECI_INT_W_FCS_ABORT		BIT(1)
+#define   ASPEED_PECI_INT_CMD_DONE		BIT(0)
+
+/* Interrupt Status Register */
+#define ASPEED_PECI_INT_STS			0x1c
+#define   ASPEED_PECI_INT_TIMING_RESULT_MASK	GENMASK(29, 16)
+	  /* bits[4..0]: Same bit fields in the 'Interrupt Register' */
+
+/* Rx/Tx Data Buffer Registers */
+#define ASPEED_PECI_W_DATA0			0x20
+#define ASPEED_PECI_W_DATA1			0x24
+#define ASPEED_PECI_W_DATA2			0x28
+#define ASPEED_PECI_W_DATA3			0x2c
+#define ASPEED_PECI_R_DATA0			0x30
+#define ASPEED_PECI_R_DATA1			0x34
+#define ASPEED_PECI_R_DATA2			0x38
+#define ASPEED_PECI_R_DATA3			0x3c
+#define ASPEED_PECI_W_DATA4			0x40
+#define ASPEED_PECI_W_DATA5			0x44
+#define ASPEED_PECI_W_DATA6			0x48
+#define ASPEED_PECI_W_DATA7			0x4c
+#define ASPEED_PECI_R_DATA4			0x50
+#define ASPEED_PECI_R_DATA5			0x54
+#define ASPEED_PECI_R_DATA6			0x58
+#define ASPEED_PECI_R_DATA7			0x5c
+#define   ASPEED_PECI_DATA_BUF_SIZE_MAX		32
+
+/* Timing Negotiation */
+#define ASPEED_PECI_RD_SAMPLING_POINT_DEFAULT	8
+#define ASPEED_PECI_RD_SAMPLING_POINT_MAX	15
+#define ASPEED_PECI_CLK_DIV_DEFAULT		0
+#define ASPEED_PECI_CLK_DIV_MAX			7
+#define ASPEED_PECI_MSG_TIMING_DEFAULT		1
+#define ASPEED_PECI_MSG_TIMING_MAX		255
+#define ASPEED_PECI_ADDR_TIMING_DEFAULT		1
+#define ASPEED_PECI_ADDR_TIMING_MAX		255
+
+/* Timeout */
+#define ASPEED_PECI_IDLE_CHECK_TIMEOUT_USEC	50000
+#define ASPEED_PECI_IDLE_CHECK_INTERVAL_USEC	10000
+#define ASPEED_PECI_CMD_TIMEOUT_MS_DEFAULT	1000
+#define ASPEED_PECI_CMD_TIMEOUT_MS_MAX		60000
+
+struct aspeed_peci {
+	struct peci_adapter	*adapter;
+	struct device		*dev;
+	void __iomem		*base;
+	struct clk		*clk;
+	struct reset_control	*rst;
+	int			irq;
+	spinlock_t		lock; /* to sync completion status handling */
+	struct completion	xfer_complete;
+	u32			status;
+	u32			cmd_timeout_ms;
+};
+
+static inline int aspeed_peci_check_idle(struct aspeed_peci *priv)
+{
+	u32 cmd_sts;
+
+	return readl_poll_timeout(priv->base + ASPEED_PECI_CMD,
+				  cmd_sts,
+				  !(cmd_sts & ASPEED_PECI_CMD_IDLE_MASK),
+				  ASPEED_PECI_IDLE_CHECK_INTERVAL_USEC,
+				  ASPEED_PECI_IDLE_CHECK_TIMEOUT_USEC);
+}
+
+static int aspeed_peci_xfer(struct peci_adapter *adapter,
+			    struct peci_xfer_msg *msg)
+{
+	struct aspeed_peci *priv = peci_get_adapdata(adapter);
+	long err, timeout = msecs_to_jiffies(priv->cmd_timeout_ms);
+	u32 peci_head, peci_state, rx_data = 0;
+	ulong flags;
+	int i, ret;
+	uint reg;
+
+	if (msg->tx_len > ASPEED_PECI_DATA_BUF_SIZE_MAX ||
+	    msg->rx_len > ASPEED_PECI_DATA_BUF_SIZE_MAX)
+		return -EINVAL;
+
+	/* Check command sts and bus idle state */
+	ret = aspeed_peci_check_idle(priv);
+	if (ret)
+		return ret; /* -ETIMEDOUT */
+
+	spin_lock_irqsave(&priv->lock, flags);
+	reinit_completion(&priv->xfer_complete);
+
+	peci_head = FIELD_PREP(ASPEED_PECI_TAGET_ADDR_MASK, msg->addr) |
+		    FIELD_PREP(ASPEED_PECI_WRITE_LEN_MASK, msg->tx_len) |
+		    FIELD_PREP(ASPEED_PECI_READ_LEN_MASK, msg->rx_len);
+
+	writel(peci_head, priv->base + ASPEED_PECI_RW_LENGTH);
+
+	for (i = 0; i < msg->tx_len; i += 4) {
+		reg = i < 16 ? ASPEED_PECI_W_DATA0 + i % 16 :
+			       ASPEED_PECI_W_DATA4 + i % 16;
+		writel(le32_to_cpup((__le32 *)&msg->tx_buf[i]),
+		       priv->base + reg);
+	}
+
+	dev_dbg(priv->dev, "HEAD : 0x%08x\n", peci_head);
+	print_hex_dump_debug("TX : ", DUMP_PREFIX_NONE, 16, 1,
+			     msg->tx_buf, msg->tx_len, true);
+
+	priv->status = 0;
+	writel(ASPEED_PECI_CMD_FIRE, priv->base + ASPEED_PECI_CMD);
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	err = wait_for_completion_interruptible_timeout(&priv->xfer_complete,
+							timeout);
+
+	spin_lock_irqsave(&priv->lock, flags);
+	dev_dbg(priv->dev, "INT_STS : 0x%08x\n", priv->status);
+	peci_state = readl(priv->base + ASPEED_PECI_CMD);
+	dev_dbg(priv->dev, "PECI_STATE : 0x%lx\n",
+		FIELD_GET(ASPEED_PECI_CMD_STS_MASK, peci_state));
+
+	writel(0, priv->base + ASPEED_PECI_CMD);
+
+	if (err <= 0 || priv->status != ASPEED_PECI_INT_CMD_DONE) {
+		if (err < 0) { /* -ERESTARTSYS */
+			ret = (int)err;
+			goto err_irqrestore;
+		} else if (err == 0) {
+			dev_dbg(priv->dev, "Timeout waiting for a response!\n");
+			ret = -ETIMEDOUT;
+			goto err_irqrestore;
+		}
+
+		dev_dbg(priv->dev, "No valid response!\n");
+		ret = -EIO;
+		goto err_irqrestore;
+	}
+
+	/*
+	 * Note that rx_len and rx_buf size can be an odd number.
+	 * Byte handling is more efficient.
+	 */
+	for (i = 0; i < msg->rx_len; i++) {
+		u8 byte_offset = i % 4;
+
+		if (byte_offset == 0) {
+			reg = i < 16 ? ASPEED_PECI_R_DATA0 + i % 16 :
+				       ASPEED_PECI_R_DATA4 + i % 16;
+			rx_data = readl(priv->base + reg);
+		}
+
+		msg->rx_buf[i] = (u8)(rx_data >> (byte_offset << 3));
+	}
+
+	print_hex_dump_debug("RX : ", DUMP_PREFIX_NONE, 16, 1,
+			     msg->rx_buf, msg->rx_len, true);
+
+	peci_state = readl(priv->base + ASPEED_PECI_CMD);
+	dev_dbg(priv->dev, "PECI_STATE : 0x%lx\n",
+		FIELD_GET(ASPEED_PECI_CMD_STS_MASK, peci_state));
+	dev_dbg(priv->dev, "------------------------\n");
+
+err_irqrestore:
+	spin_unlock_irqrestore(&priv->lock, flags);
+
+	return ret;
+}
+
+static irqreturn_t aspeed_peci_irq_handler(int irq, void *arg)
+{
+	struct aspeed_peci *priv = arg;
+	u32 status;
+
+	spin_lock(&priv->lock);
+	status = readl(priv->base + ASPEED_PECI_INT_STS);
+	writel(status, priv->base + ASPEED_PECI_INT_STS);
+	priv->status |= (status & ASPEED_PECI_INT_MASK);
+
+	/*
+	 * In most cases, interrupt bits will be set one by one but also note
+	 * that multiple interrupt bits could be set at the same time.
+	 */
+	if (status & ASPEED_PECI_INT_BUS_TIMEOUT)
+		dev_dbg(priv->dev, "ASPEED_PECI_INT_BUS_TIMEOUT\n");
+
+	if (status & ASPEED_PECI_INT_BUS_CONNECT)
+		dev_dbg(priv->dev, "ASPEED_PECI_INT_BUS_CONNECT\n");
+
+	if (status & ASPEED_PECI_INT_W_FCS_BAD)
+		dev_dbg(priv->dev, "ASPEED_PECI_INT_W_FCS_BAD\n");
+
+	if (status & ASPEED_PECI_INT_W_FCS_ABORT)
+		dev_dbg(priv->dev, "ASPEED_PECI_INT_W_FCS_ABORT\n");
+
+	/*
+	 * All commands should be ended up with a ASPEED_PECI_INT_CMD_DONE bit
+	 * set even in an error case.
+	 */
+	if (status & ASPEED_PECI_INT_CMD_DONE) {
+		dev_dbg(priv->dev, "ASPEED_PECI_INT_CMD_DONE\n");
+		complete(&priv->xfer_complete);
+	}
+
+	spin_unlock(&priv->lock);
+
+	return IRQ_HANDLED;
+}
+
+static int aspeed_peci_init_ctrl(struct aspeed_peci *priv)
+{
+	u32 msg_timing, addr_timing, rd_sampling_point;
+	u32 clk_freq, clk_divisor, clk_div_val = 0;
+	int ret;
+
+	priv->clk = devm_clk_get(priv->dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		dev_err(priv->dev, "Failed to get clk source.\n");
+		return PTR_ERR(priv->clk);
+	}
+
+	ret = clk_prepare_enable(priv->clk);
+	if (ret) {
+		dev_err(priv->dev, "Failed to enable clock.\n");
+		return ret;
+	}
+
+	ret = device_property_read_u32(priv->dev, "clock-frequency", &clk_freq);
+	if (ret) {
+		dev_err(priv->dev,
+			"Could not read clock-frequency property.\n");
+		clk_disable_unprepare(priv->clk);
+		return ret;
+	}
+
+	clk_divisor = clk_get_rate(priv->clk) / clk_freq;
+
+	while ((clk_divisor >>= 1) && (clk_div_val < ASPEED_PECI_CLK_DIV_MAX))
+		clk_div_val++;
+
+	ret = device_property_read_u32(priv->dev, "msg-timing", &msg_timing);
+	if (ret || msg_timing > ASPEED_PECI_MSG_TIMING_MAX) {
+		if (!ret)
+			dev_warn(priv->dev,
+				 "Invalid msg-timing : %u, Use default : %u\n",
+				 msg_timing, ASPEED_PECI_MSG_TIMING_DEFAULT);
+		msg_timing = ASPEED_PECI_MSG_TIMING_DEFAULT;
+	}
+
+	ret = device_property_read_u32(priv->dev, "addr-timing", &addr_timing);
+	if (ret || addr_timing > ASPEED_PECI_ADDR_TIMING_MAX) {
+		if (!ret)
+			dev_warn(priv->dev,
+				 "Invalid addr-timing : %u, Use default : %u\n",
+				 addr_timing, ASPEED_PECI_ADDR_TIMING_DEFAULT);
+		addr_timing = ASPEED_PECI_ADDR_TIMING_DEFAULT;
+	}
+
+	ret = device_property_read_u32(priv->dev, "rd-sampling-point",
+				       &rd_sampling_point);
+	if (ret || rd_sampling_point > ASPEED_PECI_RD_SAMPLING_POINT_MAX) {
+		if (!ret)
+			dev_warn(priv->dev,
+				 "Invalid rd-sampling-point : %u. Use default : %u\n",
+				 rd_sampling_point,
+				 ASPEED_PECI_RD_SAMPLING_POINT_DEFAULT);
+		rd_sampling_point = ASPEED_PECI_RD_SAMPLING_POINT_DEFAULT;
+	}
+
+	ret = device_property_read_u32(priv->dev, "cmd-timeout-ms",
+				       &priv->cmd_timeout_ms);
+	if (ret || priv->cmd_timeout_ms > ASPEED_PECI_CMD_TIMEOUT_MS_MAX ||
+	    priv->cmd_timeout_ms == 0) {
+		if (!ret)
+			dev_warn(priv->dev,
+				 "Invalid cmd-timeout-ms : %u. Use default : %u\n",
+				 priv->cmd_timeout_ms,
+				 ASPEED_PECI_CMD_TIMEOUT_MS_DEFAULT);
+		priv->cmd_timeout_ms = ASPEED_PECI_CMD_TIMEOUT_MS_DEFAULT;
+	}
+
+	writel(FIELD_PREP(ASPEED_PECI_CTRL_CLK_DIV_MASK,
+			  ASPEED_PECI_CLK_DIV_DEFAULT) |
+	       ASPEED_PECI_CTRL_PECI_CLK_EN, priv->base + ASPEED_PECI_CTRL);
+
+	/*
+	 * Timing negotiation period setting.
+	 * The unit of the programmed value is 4 times of PECI clock period.
+	 */
+	writel(FIELD_PREP(ASPEED_PECI_TIMING_MESSAGE_MASK, msg_timing) |
+	       FIELD_PREP(ASPEED_PECI_TIMING_ADDRESS_MASK, addr_timing),
+	       priv->base + ASPEED_PECI_TIMING_NEGOTIATION);
+
+	/* Clear interrupts */
+	writel(readl(priv->base + ASPEED_PECI_INT_STS) | ASPEED_PECI_INT_MASK,
+	       priv->base + ASPEED_PECI_INT_STS);
+
+	/* Set timing negotiation mode and enable interrupts */
+	writel(FIELD_PREP(ASPEED_PECI_TIMING_NEGO_SEL_MASK,
+			  ASPEED_PECI_1ST_BIT_OF_ADDR_NEGO) |
+	       ASPEED_PECI_INT_MASK, priv->base + ASPEED_PECI_INT_CTRL);
+
+	/* Read sampling point and clock speed setting */
+	writel(FIELD_PREP(ASPEED_PECI_CTRL_SAMPLING_MASK, rd_sampling_point) |
+	       FIELD_PREP(ASPEED_PECI_CTRL_CLK_DIV_MASK, clk_div_val) |
+	       ASPEED_PECI_CTRL_PECI_EN | ASPEED_PECI_CTRL_PECI_CLK_EN,
+	       priv->base + ASPEED_PECI_CTRL);
+
+	return 0;
+}
+
+static int aspeed_peci_probe(struct platform_device *pdev)
+{
+	struct peci_adapter *adapter;
+	struct aspeed_peci *priv;
+	int ret;
+
+	adapter = peci_alloc_adapter(&pdev->dev, sizeof(*priv));
+	if (!adapter)
+		return -ENOMEM;
+
+	priv = peci_get_adapdata(adapter);
+	priv->adapter = adapter;
+	priv->dev = &pdev->dev;
+	dev_set_drvdata(&pdev->dev, priv);
+
+	priv->base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(priv->base)) {
+		ret = PTR_ERR(priv->base);
+		goto err_put_adapter_dev;
+	}
+
+	priv->irq = platform_get_irq(pdev, 0);
+	if (!priv->irq) {
+		ret = -ENODEV;
+		goto err_put_adapter_dev;
+	}
+
+	ret = devm_request_irq(&pdev->dev, priv->irq, aspeed_peci_irq_handler,
+			       0, "peci-aspeed-irq", priv);
+	if (ret)
+		goto err_put_adapter_dev;
+
+	init_completion(&priv->xfer_complete);
+	spin_lock_init(&priv->lock);
+
+	priv->adapter->owner = THIS_MODULE;
+	priv->adapter->dev.of_node = of_node_get(dev_of_node(priv->dev));
+	strlcpy(priv->adapter->name, pdev->name, sizeof(priv->adapter->name));
+	priv->adapter->xfer = aspeed_peci_xfer;
+	priv->adapter->use_dma = false;
+
+	priv->rst = devm_reset_control_get(&pdev->dev, NULL);
+	if (IS_ERR(priv->rst)) {
+		dev_err(&pdev->dev,
+			"missing or invalid reset controller entry\n");
+		ret = PTR_ERR(priv->rst);
+		goto err_put_adapter_dev;
+	}
+	reset_control_deassert(priv->rst);
+
+	ret = aspeed_peci_init_ctrl(priv);
+	if (ret)
+		goto err_put_adapter_dev;
+
+	ret = peci_add_adapter(priv->adapter);
+	if (ret)
+		goto err_put_adapter_dev;
+
+	dev_info(&pdev->dev, "peci bus %d registered, irq %d\n",
+		 priv->adapter->nr, priv->irq);
+
+	return 0;
+
+err_put_adapter_dev:
+	put_device(&adapter->dev);
+
+	return ret;
+}
+
+static int aspeed_peci_remove(struct platform_device *pdev)
+{
+	struct aspeed_peci *priv = dev_get_drvdata(&pdev->dev);
+
+	peci_del_adapter(priv->adapter);
+	complete(&priv->xfer_complete);
+	clk_disable_unprepare(priv->clk);
+	reset_control_assert(priv->rst);
+	of_node_put(priv->adapter->dev.of_node);
+
+	return 0;
+}
+
+static const struct of_device_id aspeed_peci_of_table[] = {
+	{ .compatible = "aspeed,ast2400-peci", },
+	{ .compatible = "aspeed,ast2500-peci", },
+	{ .compatible = "aspeed,ast2600-peci", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, aspeed_peci_of_table);
+
+static struct platform_driver aspeed_peci_driver = {
+	.probe  = aspeed_peci_probe,
+	.remove = aspeed_peci_remove,
+	.driver = {
+		.name           = KBUILD_MODNAME,
+		.of_match_table = of_match_ptr(aspeed_peci_of_table),
+	},
+};
+module_platform_driver(aspeed_peci_driver);
+
+MODULE_AUTHOR("Ryan Chen <ryan_chen@aspeedtech.com>");
+MODULE_AUTHOR("Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>");
+MODULE_DESCRIPTION("ASPEED PECI driver");
+MODULE_LICENSE("GPL v2");