linux/drivers/peci/controller/peci-aspeed.c

// SPDX-License-Identifier: GPL-2.0-only
// Copyright (c) 2012-2017 ASPEED Technology Inc.
// Copyright (c) 2018-2021 Intel Corporation

#include <linux/unaligned.h>

#include <linux/bitfield.h>
#include <linux/clk.h>
#include <linux/clkdev.h>
#include <linux/clk-provider.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/jiffies.h>
#include <linux/math.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_RD_MODE_MASK		GENMASK(13, 12)
#define     ASPEED_PECI_CTRL_RD_MODE_DBG	BIT(13)
#define     ASPEED_PECI_CTRL_RD_MODE_COUNT	BIT(12)
#define   ASPEED_PECI_CTRL_CLK_SRC_HCLK		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_CONTENTION_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_T_NEGO_MSG_MASK		GENMASK(15, 8)
#define   ASPEED_PECI_T_NEGO_ADDR_MASK		GENMASK(7, 0)

/* Command Register */
#define ASPEED_PECI_CMD				0x08
#define   ASPEED_PECI_CMD_PIN_MONITORING	BIT(31)
#define   ASPEED_PECI_CMD_STS_MASK		GENMASK(27, 24)
#define     ASPEED_PECI_CMD_STS_ADDR_T_NEGO	0x3
#define   ASPEED_PECI_CMD_IDLE_MASK		\
	  (ASPEED_PECI_CMD_STS_MASK | ASPEED_PECI_CMD_PIN_MONITORING)
#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_RD_LEN_MASK		GENMASK(23, 16)
#define   ASPEED_PECI_WR_LEN_MASK		GENMASK(15, 8)
#define   ASPEED_PECI_TARGET_ADDR_MASK		GENMASK(7, 0)

/* Expected FCS Data Register */
#define ASPEED_PECI_EXPECTED_FCS		0x10
#define   ASPEED_PECI_EXPECTED_RD_FCS_MASK	GENMASK(23, 16)
#define   ASPEED_PECI_EXPECTED_AW_FCS_AUTO_MASK	GENMASK(15, 8)
#define   ASPEED_PECI_EXPECTED_WR_FCS_MASK	GENMASK(7, 0)

/* Captured FCS Data Register */
#define ASPEED_PECI_CAPTURED_FCS		0x14
#define   ASPEED_PECI_CAPTURED_RD_FCS_MASK	GENMASK(23, 16)
#define   ASPEED_PECI_CAPTURED_WR_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_CONTENTION	BIT(3)
#define     ASPEED_PECI_INT_WR_FCS_BAD		BIT(2)
#define     ASPEED_PECI_INT_WR_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_WR_DATA0			0x20
#define ASPEED_PECI_WR_DATA1			0x24
#define ASPEED_PECI_WR_DATA2			0x28
#define ASPEED_PECI_WR_DATA3			0x2c
#define ASPEED_PECI_RD_DATA0			0x30
#define ASPEED_PECI_RD_DATA1			0x34
#define ASPEED_PECI_RD_DATA2			0x38
#define ASPEED_PECI_RD_DATA3			0x3c
#define ASPEED_PECI_WR_DATA4			0x40
#define ASPEED_PECI_WR_DATA5			0x44
#define ASPEED_PECI_WR_DATA6			0x48
#define ASPEED_PECI_WR_DATA7			0x4c
#define ASPEED_PECI_RD_DATA4			0x50
#define ASPEED_PECI_RD_DATA5			0x54
#define ASPEED_PECI_RD_DATA6			0x58
#define ASPEED_PECI_RD_DATA7			0x5c
#define   ASPEED_PECI_DATA_BUF_SIZE_MAX		32

/* Timing Negotiation */
#define ASPEED_PECI_CLK_FREQUENCY_MIN		2000
#define ASPEED_PECI_CLK_FREQUENCY_DEFAULT	1000000
#define ASPEED_PECI_CLK_FREQUENCY_MAX		2000000
#define ASPEED_PECI_RD_SAMPLING_POINT_DEFAULT	8
/* Timeout */
#define ASPEED_PECI_IDLE_CHECK_TIMEOUT_US	(50 * USEC_PER_MSEC)
#define ASPEED_PECI_IDLE_CHECK_INTERVAL_US	(10 * USEC_PER_MSEC)
#define ASPEED_PECI_CMD_TIMEOUT_MS_DEFAULT	1000
#define ASPEED_PECI_CMD_TIMEOUT_MS_MAX		1000

#define ASPEED_PECI_CLK_DIV1(msg_timing) (4 * (msg_timing) + 1)
#define ASPEED_PECI_CLK_DIV2(clk_div_exp) BIT(clk_div_exp)
#define ASPEED_PECI_CLK_DIV(msg_timing, clk_div_exp) \
	(4 * ASPEED_PECI_CLK_DIV1(msg_timing) * ASPEED_PECI_CLK_DIV2(clk_div_exp))

struct aspeed_peci {
	struct peci_controller *controller;
	struct device *dev;
	void __iomem *base;
	struct reset_control *rst;
	int irq;
	spinlock_t lock; /* to sync completion status handling */
	struct completion xfer_complete;
	struct clk *clk;
	u32 clk_frequency;
	u32 status;
	u32 cmd_timeout_ms;
};

struct clk_aspeed_peci {
	struct clk_hw hw;
	struct aspeed_peci *aspeed_peci;
};

static void aspeed_peci_controller_enable(struct aspeed_peci *priv)
{
	u32 val = readl(priv->base + ASPEED_PECI_CTRL);

	val |= ASPEED_PECI_CTRL_PECI_CLK_EN;
	val |= ASPEED_PECI_CTRL_PECI_EN;

	writel(val, priv->base + ASPEED_PECI_CTRL);
}

static void aspeed_peci_init_regs(struct aspeed_peci *priv)
{
	u32 val;

	/* Clear interrupts */
	writel(ASPEED_PECI_INT_MASK, priv->base + ASPEED_PECI_INT_STS);

	/* Set timing negotiation mode and enable interrupts */
	val = FIELD_PREP(ASPEED_PECI_TIMING_NEGO_SEL_MASK, ASPEED_PECI_1ST_BIT_OF_ADDR_NEGO);
	val |= ASPEED_PECI_INT_MASK;
	writel(val, priv->base + ASPEED_PECI_INT_CTRL);

	val = FIELD_PREP(ASPEED_PECI_CTRL_SAMPLING_MASK, ASPEED_PECI_RD_SAMPLING_POINT_DEFAULT);
	writel(val, priv->base + ASPEED_PECI_CTRL);
}

static int aspeed_peci_check_idle(struct aspeed_peci *priv)
{
	u32 cmd_sts = readl(priv->base + ASPEED_PECI_CMD);
	int ret;

	/*
	 * Under normal circumstances, we expect to be idle here.
	 * In case there were any errors/timeouts that led to the situation
	 * where the hardware is not in idle state - we need to reset and
	 * reinitialize it to avoid potential controller hang.
	 */
	if (FIELD_GET(ASPEED_PECI_CMD_STS_MASK, cmd_sts)) {
		ret = reset_control_assert(priv->rst);
		if (ret) {
			dev_err(priv->dev, "cannot assert reset control\n");
			return ret;
		}

		ret = reset_control_deassert(priv->rst);
		if (ret) {
			dev_err(priv->dev, "cannot deassert reset control\n");
			return ret;
		}

		aspeed_peci_init_regs(priv);

		ret = clk_set_rate(priv->clk, priv->clk_frequency);
		if (ret < 0) {
			dev_err(priv->dev, "cannot set clock frequency\n");
			return ret;
		}

		aspeed_peci_controller_enable(priv);
	}

	return readl_poll_timeout(priv->base + ASPEED_PECI_CMD,
				  cmd_sts,
				  !(cmd_sts & ASPEED_PECI_CMD_IDLE_MASK),
				  ASPEED_PECI_IDLE_CHECK_INTERVAL_US,
				  ASPEED_PECI_IDLE_CHECK_TIMEOUT_US);
}

static int aspeed_peci_xfer(struct peci_controller *controller,
			    u8 addr, struct peci_request *req)
{
	struct aspeed_peci *priv = dev_get_drvdata(controller->dev.parent);
	unsigned long timeout = msecs_to_jiffies(priv->cmd_timeout_ms);
	u32 peci_head;
	int ret, i;

	if (req->tx.len > ASPEED_PECI_DATA_BUF_SIZE_MAX ||
	    req->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_irq(&priv->lock);
	reinit_completion(&priv->xfer_complete);

	peci_head = FIELD_PREP(ASPEED_PECI_TARGET_ADDR_MASK, addr) |
		    FIELD_PREP(ASPEED_PECI_WR_LEN_MASK, req->tx.len) |
		    FIELD_PREP(ASPEED_PECI_RD_LEN_MASK, req->rx.len);

	writel(peci_head, priv->base + ASPEED_PECI_RW_LENGTH);

	for (i = 0; i < req->tx.len; i += 4) {
		u32 reg = (i < 16 ? ASPEED_PECI_WR_DATA0 : ASPEED_PECI_WR_DATA4) + i % 16;

		writel(get_unaligned_le32(&req->tx.buf[i]), priv->base + reg);
	}

#if IS_ENABLED(CONFIG_DYNAMIC_DEBUG)
	dev_dbg(priv->dev, "HEAD : %#08x\n", peci_head);
	print_hex_dump_bytes("TX : ", DUMP_PREFIX_NONE, req->tx.buf, req->tx.len);
#endif

	priv->status = 0;
	writel(ASPEED_PECI_CMD_FIRE, priv->base + ASPEED_PECI_CMD);
	spin_unlock_irq(&priv->lock);

	ret = wait_for_completion_interruptible_timeout(&priv->xfer_complete, timeout);
	if (ret < 0)
		return ret;

	if (ret == 0) {
		dev_dbg(priv->dev, "timeout waiting for a response\n");
		return -ETIMEDOUT;
	}

	spin_lock_irq(&priv->lock);

	if (priv->status != ASPEED_PECI_INT_CMD_DONE) {
		spin_unlock_irq(&priv->lock);
		dev_dbg(priv->dev, "no valid response, status: %#02x\n", priv->status);
		return -EIO;
	}

	spin_unlock_irq(&priv->lock);

	/*
	 * We need to use dword reads for register access, make sure that the
	 * buffer size is multiple of 4-bytes.
	 */
	BUILD_BUG_ON(PECI_REQUEST_MAX_BUF_SIZE % 4);

	for (i = 0; i < req->rx.len; i += 4) {
		u32 reg = (i < 16 ? ASPEED_PECI_RD_DATA0 : ASPEED_PECI_RD_DATA4) + i % 16;
		u32 rx_data = readl(priv->base + reg);

		put_unaligned_le32(rx_data, &req->rx.buf[i]);
	}

#if IS_ENABLED(CONFIG_DYNAMIC_DEBUG)
	print_hex_dump_bytes("RX : ", DUMP_PREFIX_NONE, req->rx.buf, req->rx.len);
#endif
	return 0;
}

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);

	/*
	 * 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)
		complete(&priv->xfer_complete);

	writel(0, priv->base + ASPEED_PECI_CMD);

	spin_unlock(&priv->lock);

	return IRQ_HANDLED;
}

static void clk_aspeed_peci_find_div_values(unsigned long rate, int *msg_timing, int *clk_div_exp)
{
	unsigned long best_diff = ~0ul, diff;
	int msg_timing_temp, clk_div_exp_temp, i, j;

	for (i = 1; i <= 255; i++)
		for (j = 0; j < 8; j++) {
			diff = abs(rate - ASPEED_PECI_CLK_DIV1(i) * ASPEED_PECI_CLK_DIV2(j));
			if (diff < best_diff) {
				msg_timing_temp = i;
				clk_div_exp_temp = j;
				best_diff = diff;
			}
		}

	*msg_timing = msg_timing_temp;
	*clk_div_exp = clk_div_exp_temp;
}

static int clk_aspeed_peci_get_div(unsigned long rate, const unsigned long *prate)
{
	unsigned long this_rate = *prate / (4 * rate);
	int msg_timing, clk_div_exp;

	clk_aspeed_peci_find_div_values(this_rate, &msg_timing, &clk_div_exp);

	return ASPEED_PECI_CLK_DIV(msg_timing, clk_div_exp);
}

static int clk_aspeed_peci_set_rate(struct clk_hw *hw, unsigned long rate,
				    unsigned long prate)
{
	struct clk_aspeed_peci *peci_clk = container_of(hw, struct clk_aspeed_peci, hw);
	struct aspeed_peci *aspeed_peci = peci_clk->aspeed_peci;
	unsigned long this_rate = prate / (4 * rate);
	int clk_div_exp, msg_timing;
	u32 val;

	clk_aspeed_peci_find_div_values(this_rate, &msg_timing, &clk_div_exp);

	val = readl(aspeed_peci->base + ASPEED_PECI_CTRL);
	val &= ~ASPEED_PECI_CTRL_CLK_DIV_MASK;
	val |= FIELD_PREP(ASPEED_PECI_CTRL_CLK_DIV_MASK, clk_div_exp);
	writel(val, aspeed_peci->base + ASPEED_PECI_CTRL);

	val = FIELD_PREP(ASPEED_PECI_T_NEGO_MSG_MASK, msg_timing);
	val |= FIELD_PREP(ASPEED_PECI_T_NEGO_ADDR_MASK, msg_timing);
	writel(val, aspeed_peci->base + ASPEED_PECI_TIMING_NEGOTIATION);

	return 0;
}

static long clk_aspeed_peci_round_rate(struct clk_hw *hw, unsigned long rate,
				       unsigned long *prate)
{
	int div = clk_aspeed_peci_get_div(rate, prate);

	return DIV_ROUND_UP_ULL(*prate, div);
}

static unsigned long clk_aspeed_peci_recalc_rate(struct clk_hw *hw, unsigned long prate)
{
	struct clk_aspeed_peci *peci_clk = container_of(hw, struct clk_aspeed_peci, hw);
	struct aspeed_peci *aspeed_peci = peci_clk->aspeed_peci;
	int div, msg_timing, addr_timing, clk_div_exp;
	u32 reg;

	reg = readl(aspeed_peci->base + ASPEED_PECI_TIMING_NEGOTIATION);
	msg_timing = FIELD_GET(ASPEED_PECI_T_NEGO_MSG_MASK, reg);
	addr_timing = FIELD_GET(ASPEED_PECI_T_NEGO_ADDR_MASK, reg);

	if (msg_timing != addr_timing)
		return 0;

	reg = readl(aspeed_peci->base + ASPEED_PECI_CTRL);
	clk_div_exp = FIELD_GET(ASPEED_PECI_CTRL_CLK_DIV_MASK, reg);

	div = ASPEED_PECI_CLK_DIV(msg_timing, clk_div_exp);

	return DIV_ROUND_UP_ULL(prate, div);
}

static const struct clk_ops clk_aspeed_peci_ops = {
	.set_rate = clk_aspeed_peci_set_rate,
	.round_rate = clk_aspeed_peci_round_rate,
	.recalc_rate = clk_aspeed_peci_recalc_rate,
};

/*
 * PECI HW contains a clock divider which is a combination of:
 *  div0: 4 (fixed divider)
 *  div1: x + 1
 *  div2: 1 << y
 * In other words, out_clk = in_clk / (div0 * div1 * div2)
 * The resulting frequency is used by PECI Controller to drive the PECI bus to
 * negotiate optimal transfer rate.
 */
static struct clk *devm_aspeed_peci_register_clk_div(struct device *dev, struct clk *parent,
						     struct aspeed_peci *priv)
{
	struct clk_aspeed_peci *peci_clk;
	struct clk_init_data init;
	const char *parent_name;
	char name[32];
	int ret;

	snprintf(name, sizeof(name), "%s_div", dev_name(dev));

	parent_name = __clk_get_name(parent);

	init.ops = &clk_aspeed_peci_ops;
	init.name = name;
	init.parent_names = (const char* []) { parent_name };
	init.num_parents = 1;
	init.flags = 0;

	peci_clk = devm_kzalloc(dev, sizeof(struct clk_aspeed_peci), GFP_KERNEL);
	if (!peci_clk)
		return ERR_PTR(-ENOMEM);

	peci_clk->hw.init = &init;
	peci_clk->aspeed_peci = priv;

	ret = devm_clk_hw_register(dev, &peci_clk->hw);
	if (ret)
		return ERR_PTR(ret);

	return peci_clk->hw.clk;
}

static void aspeed_peci_property_sanitize(struct device *dev, const char *propname,
					  u32 min, u32 max, u32 default_val, u32 *propval)
{
	u32 val;
	int ret;

	ret = device_property_read_u32(dev, propname, &val);
	if (ret) {
		val = default_val;
	} else if (val > max || val < min) {
		dev_warn(dev, "invalid %s: %u, falling back to: %u\n",
			 propname, val, default_val);

		val = default_val;
	}

	*propval = val;
}

static void aspeed_peci_property_setup(struct aspeed_peci *priv)
{
	aspeed_peci_property_sanitize(priv->dev, "clock-frequency",
				      ASPEED_PECI_CLK_FREQUENCY_MIN, ASPEED_PECI_CLK_FREQUENCY_MAX,
				      ASPEED_PECI_CLK_FREQUENCY_DEFAULT, &priv->clk_frequency);
	aspeed_peci_property_sanitize(priv->dev, "cmd-timeout-ms",
				      1, ASPEED_PECI_CMD_TIMEOUT_MS_MAX,
				      ASPEED_PECI_CMD_TIMEOUT_MS_DEFAULT, &priv->cmd_timeout_ms);
}

static const struct peci_controller_ops aspeed_ops = {
	.xfer = aspeed_peci_xfer,
};

static void aspeed_peci_reset_control_release(void *data)
{
	reset_control_assert(data);
}

static int devm_aspeed_peci_reset_control_deassert(struct device *dev, struct reset_control *rst)
{
	int ret;

	ret = reset_control_deassert(rst);
	if (ret)
		return ret;

	return devm_add_action_or_reset(dev, aspeed_peci_reset_control_release, rst);
}

static void aspeed_peci_clk_release(void *data)
{
	clk_disable_unprepare(data);
}

static int devm_aspeed_peci_clk_enable(struct device *dev, struct clk *clk)
{
	int ret;

	ret = clk_prepare_enable(clk);
	if (ret)
		return ret;

	return devm_add_action_or_reset(dev, aspeed_peci_clk_release, clk);
}

static int aspeed_peci_probe(struct platform_device *pdev)
{
	struct peci_controller *controller;
	struct aspeed_peci *priv;
	struct clk *ref_clk;
	int ret;

	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
	if (!priv)
		return -ENOMEM;

	priv->dev = &pdev->dev;
	dev_set_drvdata(priv->dev, priv);

	priv->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(priv->base))
		return PTR_ERR(priv->base);

	priv->irq = platform_get_irq(pdev, 0);
	if (priv->irq < 0)
		return priv->irq;

	ret = devm_request_irq(&pdev->dev, priv->irq, aspeed_peci_irq_handler,
			       0, "peci-aspeed", priv);
	if (ret)
		return ret;

	init_completion(&priv->xfer_complete);
	spin_lock_init(&priv->lock);

	priv->rst = devm_reset_control_get(&pdev->dev, NULL);
	if (IS_ERR(priv->rst))
		return dev_err_probe(priv->dev, PTR_ERR(priv->rst),
				     "failed to get reset control\n");

	ret = devm_aspeed_peci_reset_control_deassert(priv->dev, priv->rst);
	if (ret)
		return dev_err_probe(priv->dev, ret, "cannot deassert reset control\n");

	aspeed_peci_property_setup(priv);

	aspeed_peci_init_regs(priv);

	ref_clk = devm_clk_get(priv->dev, NULL);
	if (IS_ERR(ref_clk))
		return dev_err_probe(priv->dev, PTR_ERR(ref_clk), "failed to get ref clock\n");

	priv->clk = devm_aspeed_peci_register_clk_div(priv->dev, ref_clk, priv);
	if (IS_ERR(priv->clk))
		return dev_err_probe(priv->dev, PTR_ERR(priv->clk), "cannot register clock\n");

	ret = clk_set_rate(priv->clk, priv->clk_frequency);
	if (ret < 0)
		return dev_err_probe(priv->dev, ret, "cannot set clock frequency\n");

	ret = devm_aspeed_peci_clk_enable(priv->dev, priv->clk);
	if (ret)
		return dev_err_probe(priv->dev, ret, "failed to enable clock\n");

	aspeed_peci_controller_enable(priv);

	controller = devm_peci_controller_add(priv->dev, &aspeed_ops);
	if (IS_ERR(controller))
		return dev_err_probe(priv->dev, PTR_ERR(controller),
				     "failed to add aspeed peci controller\n");

	priv->controller = controller;

	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,
	.driver = {
		.name           = "peci-aspeed",
		.of_match_table = 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");
MODULE_IMPORT_NS(PECI);