Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

12 files changed, 2516 insertions, 0 deletions

diff --git a/drivers/peci/Kconfig b/drivers/peci/Kconfig
new file mode 100644
index 0000000000..89872ad833
--- /dev/null
+++ b/drivers/peci/Kconfig
@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+menuconfig PECI
+	tristate "PECI support"
+	help
+	  The Platform Environment Control Interface (PECI) is an interface
+	  that provides a communication channel to Intel processors and
+	  chipset components from external monitoring or control devices.
+
+	  If you are building a Baseboard Management Controller (BMC) kernel
+	  for Intel platform say Y here and also to the specific driver for
+	  your adapter(s) below. If unsure say N.
+
+	  This support is also available as a module. If so, the module
+	  will be called peci.
+
+if PECI
+
+config PECI_CPU
+	tristate "PECI CPU"
+	select AUXILIARY_BUS
+	help
+	  This option enables peci-cpu driver for Intel processors. It is
+	  responsible for creating auxiliary devices that can subsequently
+	  be used by other drivers in order to perform various
+	  functionalities such as e.g. temperature monitoring.
+
+	  Additional drivers must be enabled in order to use the functionality
+	  of the device.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called peci-cpu.
+
+source "drivers/peci/controller/Kconfig"
+
+endif # PECI
diff --git a/drivers/peci/Makefile b/drivers/peci/Makefile
new file mode 100644
index 0000000000..7de18137e7
--- /dev/null
+++ b/drivers/peci/Makefile
@@ -0,0 +1,10 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+# Core functionality
+peci-y := core.o request.o device.o sysfs.o
+obj-$(CONFIG_PECI) += peci.o
+peci-cpu-y := cpu.o
+obj-$(CONFIG_PECI_CPU) += peci-cpu.o
+
+# Hardware specific bus drivers
+obj-y += controller/
diff --git a/drivers/peci/controller/Kconfig b/drivers/peci/controller/Kconfig
new file mode 100644
index 0000000000..4f9c245ad0
--- /dev/null
+++ b/drivers/peci/controller/Kconfig
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config PECI_ASPEED
+	tristate "ASPEED PECI support"
+	depends on ARCH_ASPEED || COMPILE_TEST
+	depends on OF
+	depends on HAS_IOMEM
+	depends on COMMON_CLK
+	help
+	  This option enables PECI controller driver for ASPEED AST2400,
+	  AST2500 and AST2600 SoCs. It allows BMC to discover devices
+	  connected to it, and communicate with them using PECI protocol.
+
+	  Say Y here if your system runs on ASPEED SoC and you are using it
+	  as BMC for Intel platform.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called peci-aspeed.
+
+config PECI_NPCM
+	tristate "Nuvoton NPCM PECI support"
+	depends on ARCH_NPCM || COMPILE_TEST
+	depends on OF
+	select REGMAP_MMIO
+	help
+	  This option enables PECI controller driver for Nuvoton NPCM7XX
+	  and NPCM8XX SoCs. It allows BMC to discover devices connected
+	  to it and communicate with them using PECI protocol.
+
+	  Say Y here if you want support for the Platform Environment Control
+	  Interface (PECI) bus adapter driver on the Nuvoton NPCM SoCs.
+
+	  This support is also available as a module. If so, the module
+	  will be called peci-npcm.
diff --git a/drivers/peci/controller/Makefile b/drivers/peci/controller/Makefile
new file mode 100644
index 0000000000..e247449bb4
--- /dev/null
+++ b/drivers/peci/controller/Makefile
@@ -0,0 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_PECI_ASPEED)	+= peci-aspeed.o
+obj-$(CONFIG_PECI_NPCM)		+= peci-npcm.o
diff --git a/drivers/peci/controller/peci-aspeed.c b/drivers/peci/controller/peci-aspeed.c
new file mode 100644
index 0000000000..7fdc25afcf
--- /dev/null
+++ b/drivers/peci/controller/peci-aspeed.c
@@ -0,0 +1,599 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2012-2017 ASPEED Technology Inc.
+// Copyright (c) 2018-2021 Intel Corporation
+
+#include <asm/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 |= 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);
diff --git a/drivers/peci/controller/peci-npcm.c b/drivers/peci/controller/peci-npcm.c
new file mode 100644
index 0000000000..ec613d35c7
--- /dev/null
+++ b/drivers/peci/controller/peci-npcm.c
@@ -0,0 +1,298 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2019 Nuvoton Technology corporation
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/interrupt.h>
+#include <linux/jiffies.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/peci.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+/* NPCM GCR module */
+#define NPCM_INTCR3_OFFSET	0x9C
+#define NPCM_INTCR3_PECIVSEL	BIT(19)
+
+/* NPCM PECI Registers */
+#define NPCM_PECI_CTL_STS	0x00
+#define NPCM_PECI_RD_LENGTH	0x04
+#define NPCM_PECI_ADDR		0x08
+#define NPCM_PECI_CMD		0x0C
+#define NPCM_PECI_CTL2		0x10
+#define NPCM_PECI_WR_LENGTH	0x1C
+#define NPCM_PECI_PDDR		0x2C
+#define NPCM_PECI_DAT_INOUT(n)	(0x100 + ((n) * 4))
+
+#define NPCM_PECI_MAX_REG	0x200
+
+/* NPCM_PECI_CTL_STS - 0x00 : Control Register */
+#define NPCM_PECI_CTRL_DONE_INT_EN	BIT(6)
+#define NPCM_PECI_CTRL_ABRT_ERR		BIT(4)
+#define NPCM_PECI_CTRL_CRC_ERR		BIT(3)
+#define NPCM_PECI_CTRL_DONE		BIT(1)
+#define NPCM_PECI_CTRL_START_BUSY	BIT(0)
+
+/* NPCM_PECI_RD_LENGTH - 0x04 : Command Register */
+#define NPCM_PECI_RD_LEN_MASK		GENMASK(6, 0)
+
+/* NPCM_PECI_CMD - 0x10 : Command Register */
+#define NPCM_PECI_CTL2_MASK		GENMASK(7, 6)
+
+/* NPCM_PECI_WR_LENGTH - 0x1C : Command Register */
+#define NPCM_PECI_WR_LEN_MASK		GENMASK(6, 0)
+
+/* NPCM_PECI_PDDR - 0x2C : Command Register */
+#define NPCM_PECI_PDDR_MASK		GENMASK(4, 0)
+
+#define NPCM_PECI_INT_MASK		(NPCM_PECI_CTRL_ABRT_ERR | \
+					 NPCM_PECI_CTRL_CRC_ERR  | \
+					 NPCM_PECI_CTRL_DONE)
+
+#define NPCM_PECI_IDLE_CHECK_TIMEOUT_USEC	(50 * USEC_PER_MSEC)
+#define NPCM_PECI_IDLE_CHECK_INTERVAL_USEC	(10 * USEC_PER_MSEC)
+#define NPCM_PECI_CMD_TIMEOUT_MS_DEFAULT	1000
+#define NPCM_PECI_CMD_TIMEOUT_MS_MAX		60000
+#define NPCM_PECI_HOST_NEG_BIT_RATE_DEFAULT	15
+#define NPCM_PECI_PULL_DOWN_DEFAULT		0
+
+struct npcm_peci {
+	u32			cmd_timeout_ms;
+	struct completion	xfer_complete;
+	struct regmap		*regmap;
+	u32			status;
+	spinlock_t		lock; /* to sync completion status handling */
+	struct peci_controller *controller;
+	struct device		*dev;
+	struct clk		*clk;
+	int			irq;
+};
+
+static int npcm_peci_xfer(struct peci_controller *controller, u8 addr, struct peci_request *req)
+{
+	struct npcm_peci *priv = dev_get_drvdata(controller->dev.parent);
+	unsigned long timeout = msecs_to_jiffies(priv->cmd_timeout_ms);
+	unsigned int msg_rd;
+	u32 cmd_sts;
+	int i, ret;
+
+	/* Check command sts and bus idle state */
+	ret = regmap_read_poll_timeout(priv->regmap, NPCM_PECI_CTL_STS, cmd_sts,
+				       !(cmd_sts & NPCM_PECI_CTRL_START_BUSY),
+				       NPCM_PECI_IDLE_CHECK_INTERVAL_USEC,
+				       NPCM_PECI_IDLE_CHECK_TIMEOUT_USEC);
+	if (ret)
+		return ret; /* -ETIMEDOUT */
+
+	spin_lock_irq(&priv->lock);
+	reinit_completion(&priv->xfer_complete);
+
+	regmap_write(priv->regmap, NPCM_PECI_ADDR, addr);
+	regmap_write(priv->regmap, NPCM_PECI_RD_LENGTH, NPCM_PECI_WR_LEN_MASK & req->rx.len);
+	regmap_write(priv->regmap, NPCM_PECI_WR_LENGTH, NPCM_PECI_WR_LEN_MASK & req->tx.len);
+
+	if (req->tx.len) {
+		regmap_write(priv->regmap, NPCM_PECI_CMD, req->tx.buf[0]);
+
+		for (i = 0; i < (req->tx.len - 1); i++)
+			regmap_write(priv->regmap, NPCM_PECI_DAT_INOUT(i), req->tx.buf[i + 1]);
+	}
+
+#if IS_ENABLED(CONFIG_DYNAMIC_DEBUG)
+	dev_dbg(priv->dev, "addr : %#02x, tx.len : %#02x, rx.len : %#02x\n",
+		addr, req->tx.len, req->rx.len);
+	print_hex_dump_bytes("TX : ", DUMP_PREFIX_NONE, req->tx.buf, req->tx.len);
+#endif
+
+	priv->status = 0;
+	regmap_update_bits(priv->regmap, NPCM_PECI_CTL_STS, NPCM_PECI_CTRL_START_BUSY,
+			   NPCM_PECI_CTRL_START_BUSY);
+
+	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 != NPCM_PECI_CTRL_DONE) {
+		spin_unlock_irq(&priv->lock);
+		dev_dbg(priv->dev, "no valid response, status: %#02x\n", priv->status);
+		return -EIO;
+	}
+
+	regmap_write(priv->regmap, NPCM_PECI_CMD, 0);
+
+	for (i = 0; i < req->rx.len; i++) {
+		regmap_read(priv->regmap, NPCM_PECI_DAT_INOUT(i), &msg_rd);
+		req->rx.buf[i] = (u8)msg_rd;
+	}
+
+	spin_unlock_irq(&priv->lock);
+
+#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 npcm_peci_irq_handler(int irq, void *arg)
+{
+	struct npcm_peci *priv = arg;
+	u32 status_ack = 0;
+	u32 status;
+
+	spin_lock(&priv->lock);
+	regmap_read(priv->regmap, NPCM_PECI_CTL_STS, &status);
+	priv->status |= (status & NPCM_PECI_INT_MASK);
+
+	if (status & NPCM_PECI_CTRL_CRC_ERR)
+		status_ack |= NPCM_PECI_CTRL_CRC_ERR;
+
+	if (status & NPCM_PECI_CTRL_ABRT_ERR)
+		status_ack |= NPCM_PECI_CTRL_ABRT_ERR;
+
+	/*
+	 * All commands should be ended up with a NPCM_PECI_CTRL_DONE
+	 * bit set even in an error case.
+	 */
+	if (status & NPCM_PECI_CTRL_DONE) {
+		status_ack |= NPCM_PECI_CTRL_DONE;
+		complete(&priv->xfer_complete);
+	}
+
+	regmap_write_bits(priv->regmap, NPCM_PECI_CTL_STS, NPCM_PECI_INT_MASK, status_ack);
+
+	spin_unlock(&priv->lock);
+	return IRQ_HANDLED;
+}
+
+static int npcm_peci_init_ctrl(struct npcm_peci *priv)
+{
+	u32 cmd_sts;
+	int ret;
+
+	priv->clk = devm_clk_get_enabled(priv->dev, NULL);
+	if (IS_ERR(priv->clk)) {
+		dev_err(priv->dev, "failed to get ref clock\n");
+		return PTR_ERR(priv->clk);
+	}
+
+	ret = device_property_read_u32(priv->dev, "cmd-timeout-ms", &priv->cmd_timeout_ms);
+	if (ret) {
+		priv->cmd_timeout_ms = NPCM_PECI_CMD_TIMEOUT_MS_DEFAULT;
+	} else if (priv->cmd_timeout_ms > NPCM_PECI_CMD_TIMEOUT_MS_MAX ||
+		   priv->cmd_timeout_ms == 0) {
+		dev_warn(priv->dev, "invalid cmd-timeout-ms: %u, falling back to: %u\n",
+			 priv->cmd_timeout_ms, NPCM_PECI_CMD_TIMEOUT_MS_DEFAULT);
+
+		priv->cmd_timeout_ms = NPCM_PECI_CMD_TIMEOUT_MS_DEFAULT;
+	}
+
+	regmap_update_bits(priv->regmap, NPCM_PECI_CTL2, NPCM_PECI_CTL2_MASK,
+			   NPCM_PECI_PULL_DOWN_DEFAULT << 6);
+
+	regmap_update_bits(priv->regmap, NPCM_PECI_PDDR, NPCM_PECI_PDDR_MASK,
+			   NPCM_PECI_HOST_NEG_BIT_RATE_DEFAULT);
+
+	ret = regmap_read_poll_timeout(priv->regmap, NPCM_PECI_CTL_STS, cmd_sts,
+				       !(cmd_sts & NPCM_PECI_CTRL_START_BUSY),
+				       NPCM_PECI_IDLE_CHECK_INTERVAL_USEC,
+				       NPCM_PECI_IDLE_CHECK_TIMEOUT_USEC);
+	if (ret)
+		return ret; /* -ETIMEDOUT */
+
+	/* PECI interrupt enable */
+	regmap_update_bits(priv->regmap, NPCM_PECI_CTL_STS, NPCM_PECI_CTRL_DONE_INT_EN,
+			   NPCM_PECI_CTRL_DONE_INT_EN);
+
+	return 0;
+}
+
+static const struct regmap_config npcm_peci_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = NPCM_PECI_MAX_REG,
+	.fast_io = true,
+};
+
+static struct peci_controller_ops npcm_ops = {
+	.xfer = npcm_peci_xfer,
+};
+
+static int npcm_peci_probe(struct platform_device *pdev)
+{
+	struct peci_controller *controller;
+	struct npcm_peci *priv;
+	void __iomem *base;
+	int ret;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->dev = &pdev->dev;
+	dev_set_drvdata(&pdev->dev, priv);
+
+	base = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(base))
+		return PTR_ERR(base);
+
+	priv->regmap = devm_regmap_init_mmio(&pdev->dev, base, &npcm_peci_regmap_config);
+	if (IS_ERR(priv->regmap))
+		return PTR_ERR(priv->regmap);
+
+	priv->irq = platform_get_irq(pdev, 0);
+	if (priv->irq < 0)
+		return priv->irq;
+
+	ret = devm_request_irq(&pdev->dev, priv->irq, npcm_peci_irq_handler,
+			       0, "peci-npcm-irq", priv);
+	if (ret)
+		return ret;
+
+	init_completion(&priv->xfer_complete);
+	spin_lock_init(&priv->lock);
+
+	ret = npcm_peci_init_ctrl(priv);
+	if (ret)
+		return ret;
+
+	controller = devm_peci_controller_add(priv->dev, &npcm_ops);
+	if (IS_ERR(controller))
+		return dev_err_probe(priv->dev, PTR_ERR(controller),
+				     "failed to add npcm peci controller\n");
+
+	priv->controller = controller;
+
+	return 0;
+}
+
+static const struct of_device_id npcm_peci_of_table[] = {
+	{ .compatible = "nuvoton,npcm750-peci", },
+	{ .compatible = "nuvoton,npcm845-peci", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, npcm_peci_of_table);
+
+static struct platform_driver npcm_peci_driver = {
+	.probe  = npcm_peci_probe,
+	.driver = {
+		.name           = KBUILD_MODNAME,
+		.of_match_table = npcm_peci_of_table,
+	},
+};
+module_platform_driver(npcm_peci_driver);
+
+MODULE_AUTHOR("Tomer Maimon <tomer.maimon@nuvoton.com>");
+MODULE_DESCRIPTION("NPCM PECI driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PECI);
diff --git a/drivers/peci/core.c b/drivers/peci/core.c
new file mode 100644
index 0000000000..0f83a9c609
--- /dev/null
+++ b/drivers/peci/core.c
@@ -0,0 +1,236 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2018-2021 Intel Corporation
+
+#include <linux/bug.h>
+#include <linux/device.h>
+#include <linux/export.h>
+#include <linux/idr.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/peci.h>
+#include <linux/pm_runtime.h>
+#include <linux/property.h>
+#include <linux/slab.h>
+
+#include "internal.h"
+
+static DEFINE_IDA(peci_controller_ida);
+
+static void peci_controller_dev_release(struct device *dev)
+{
+	struct peci_controller *controller = to_peci_controller(dev);
+
+	mutex_destroy(&controller->bus_lock);
+	ida_free(&peci_controller_ida, controller->id);
+	kfree(controller);
+}
+
+struct device_type peci_controller_type = {
+	.release	= peci_controller_dev_release,
+};
+
+int peci_controller_scan_devices(struct peci_controller *controller)
+{
+	int ret;
+	u8 addr;
+
+	for (addr = PECI_BASE_ADDR; addr < PECI_BASE_ADDR + PECI_DEVICE_NUM_MAX; addr++) {
+		ret = peci_device_create(controller, addr);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static struct peci_controller *peci_controller_alloc(struct device *dev,
+						     const struct peci_controller_ops *ops)
+{
+	struct peci_controller *controller;
+	int ret;
+
+	if (!ops->xfer)
+		return ERR_PTR(-EINVAL);
+
+	controller = kzalloc(sizeof(*controller), GFP_KERNEL);
+	if (!controller)
+		return ERR_PTR(-ENOMEM);
+
+	ret = ida_alloc_max(&peci_controller_ida, U8_MAX, GFP_KERNEL);
+	if (ret < 0)
+		goto err;
+	controller->id = ret;
+
+	controller->ops = ops;
+
+	controller->dev.parent = dev;
+	controller->dev.bus = &peci_bus_type;
+	controller->dev.type = &peci_controller_type;
+
+	device_initialize(&controller->dev);
+
+	mutex_init(&controller->bus_lock);
+
+	return controller;
+
+err:
+	kfree(controller);
+	return ERR_PTR(ret);
+}
+
+static int unregister_child(struct device *dev, void *dummy)
+{
+	peci_device_destroy(to_peci_device(dev));
+
+	return 0;
+}
+
+static void unregister_controller(void *_controller)
+{
+	struct peci_controller *controller = _controller;
+
+	/*
+	 * Detach any active PECI devices. This can't fail, thus we do not
+	 * check the returned value.
+	 */
+	device_for_each_child_reverse(&controller->dev, NULL, unregister_child);
+
+	device_unregister(&controller->dev);
+
+	fwnode_handle_put(controller->dev.fwnode);
+
+	pm_runtime_disable(&controller->dev);
+}
+
+/**
+ * devm_peci_controller_add() - add PECI controller
+ * @dev: device for devm operations
+ * @ops: pointer to controller specific methods
+ *
+ * In final stage of its probe(), peci_controller driver calls
+ * devm_peci_controller_add() to register itself with the PECI bus.
+ *
+ * Return: Pointer to the newly allocated controller or ERR_PTR() in case of failure.
+ */
+struct peci_controller *devm_peci_controller_add(struct device *dev,
+						 const struct peci_controller_ops *ops)
+{
+	struct peci_controller *controller;
+	int ret;
+
+	controller = peci_controller_alloc(dev, ops);
+	if (IS_ERR(controller))
+		return controller;
+
+	ret = dev_set_name(&controller->dev, "peci-%d", controller->id);
+	if (ret)
+		goto err_put;
+
+	pm_runtime_no_callbacks(&controller->dev);
+	pm_suspend_ignore_children(&controller->dev, true);
+	pm_runtime_enable(&controller->dev);
+
+	device_set_node(&controller->dev, fwnode_handle_get(dev_fwnode(dev)));
+
+	ret = device_add(&controller->dev);
+	if (ret)
+		goto err_fwnode;
+
+	ret = devm_add_action_or_reset(dev, unregister_controller, controller);
+	if (ret)
+		return ERR_PTR(ret);
+
+	/*
+	 * Ignoring retval since failures during scan are non-critical for
+	 * controller itself.
+	 */
+	peci_controller_scan_devices(controller);
+
+	return controller;
+
+err_fwnode:
+	fwnode_handle_put(controller->dev.fwnode);
+
+	pm_runtime_disable(&controller->dev);
+
+err_put:
+	put_device(&controller->dev);
+
+	return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_NS_GPL(devm_peci_controller_add, PECI);
+
+static const struct peci_device_id *
+peci_bus_match_device_id(const struct peci_device_id *id, struct peci_device *device)
+{
+	while (id->family != 0) {
+		if (id->family == device->info.family &&
+		    id->model == device->info.model)
+			return id;
+		id++;
+	}
+
+	return NULL;
+}
+
+static int peci_bus_device_match(struct device *dev, struct device_driver *drv)
+{
+	struct peci_device *device = to_peci_device(dev);
+	struct peci_driver *peci_drv = to_peci_driver(drv);
+
+	if (dev->type != &peci_device_type)
+		return 0;
+
+	return !!peci_bus_match_device_id(peci_drv->id_table, device);
+}
+
+static int peci_bus_device_probe(struct device *dev)
+{
+	struct peci_device *device = to_peci_device(dev);
+	struct peci_driver *driver = to_peci_driver(dev->driver);
+
+	return driver->probe(device, peci_bus_match_device_id(driver->id_table, device));
+}
+
+static void peci_bus_device_remove(struct device *dev)
+{
+	struct peci_device *device = to_peci_device(dev);
+	struct peci_driver *driver = to_peci_driver(dev->driver);
+
+	if (driver->remove)
+		driver->remove(device);
+}
+
+struct bus_type peci_bus_type = {
+	.name		= "peci",
+	.match		= peci_bus_device_match,
+	.probe		= peci_bus_device_probe,
+	.remove		= peci_bus_device_remove,
+	.bus_groups	= peci_bus_groups,
+};
+
+static int __init peci_init(void)
+{
+	int ret;
+
+	ret = bus_register(&peci_bus_type);
+	if (ret < 0) {
+		pr_err("peci: failed to register PECI bus type!\n");
+		return ret;
+	}
+
+	return 0;
+}
+module_init(peci_init);
+
+static void __exit peci_exit(void)
+{
+	bus_unregister(&peci_bus_type);
+}
+module_exit(peci_exit);
+
+MODULE_AUTHOR("Jason M Bills <jason.m.bills@linux.intel.com>");
+MODULE_AUTHOR("Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>");
+MODULE_AUTHOR("Iwona Winiarska <iwona.winiarska@intel.com>");
+MODULE_DESCRIPTION("PECI bus core module");
+MODULE_LICENSE("GPL");
diff --git a/drivers/peci/cpu.c b/drivers/peci/cpu.c
new file mode 100644
index 0000000000..bd990acd92
--- /dev/null
+++ b/drivers/peci/cpu.c
@@ -0,0 +1,347 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2021 Intel Corporation
+
+#include <linux/auxiliary_bus.h>
+#include <linux/module.h>
+#include <linux/peci.h>
+#include <linux/peci-cpu.h>
+#include <linux/slab.h>
+
+#include "internal.h"
+
+/**
+ * peci_temp_read() - read the maximum die temperature from PECI target device
+ * @device: PECI device to which request is going to be sent
+ * @temp_raw: where to store the read temperature
+ *
+ * It uses GetTemp PECI command.
+ *
+ * Return: 0 if succeeded, other values in case errors.
+ */
+int peci_temp_read(struct peci_device *device, s16 *temp_raw)
+{
+	struct peci_request *req;
+
+	req = peci_xfer_get_temp(device);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+
+	*temp_raw = peci_request_temp_read(req);
+
+	peci_request_free(req);
+
+	return 0;
+}
+EXPORT_SYMBOL_NS_GPL(peci_temp_read, PECI_CPU);
+
+/**
+ * peci_pcs_read() - read PCS register
+ * @device: PECI device to which request is going to be sent
+ * @index: PCS index
+ * @param: PCS parameter
+ * @data: where to store the read data
+ *
+ * It uses RdPkgConfig PECI command.
+ *
+ * Return: 0 if succeeded, other values in case errors.
+ */
+int peci_pcs_read(struct peci_device *device, u8 index, u16 param, u32 *data)
+{
+	struct peci_request *req;
+	int ret;
+
+	req = peci_xfer_pkg_cfg_readl(device, index, param);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+
+	ret = peci_request_status(req);
+	if (ret)
+		goto out_req_free;
+
+	*data = peci_request_data_readl(req);
+out_req_free:
+	peci_request_free(req);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(peci_pcs_read, PECI_CPU);
+
+/**
+ * peci_pci_local_read() - read 32-bit memory location using raw address
+ * @device: PECI device to which request is going to be sent
+ * @bus: bus
+ * @dev: device
+ * @func: function
+ * @reg: register
+ * @data: where to store the read data
+ *
+ * It uses RdPCIConfigLocal PECI command.
+ *
+ * Return: 0 if succeeded, other values in case errors.
+ */
+int peci_pci_local_read(struct peci_device *device, u8 bus, u8 dev, u8 func,
+			u16 reg, u32 *data)
+{
+	struct peci_request *req;
+	int ret;
+
+	req = peci_xfer_pci_cfg_local_readl(device, bus, dev, func, reg);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+
+	ret = peci_request_status(req);
+	if (ret)
+		goto out_req_free;
+
+	*data = peci_request_data_readl(req);
+out_req_free:
+	peci_request_free(req);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(peci_pci_local_read, PECI_CPU);
+
+/**
+ * peci_ep_pci_local_read() - read 32-bit memory location using raw address
+ * @device: PECI device to which request is going to be sent
+ * @seg: PCI segment
+ * @bus: bus
+ * @dev: device
+ * @func: function
+ * @reg: register
+ * @data: where to store the read data
+ *
+ * Like &peci_pci_local_read, but it uses RdEndpointConfig PECI command.
+ *
+ * Return: 0 if succeeded, other values in case errors.
+ */
+int peci_ep_pci_local_read(struct peci_device *device, u8 seg,
+			   u8 bus, u8 dev, u8 func, u16 reg, u32 *data)
+{
+	struct peci_request *req;
+	int ret;
+
+	req = peci_xfer_ep_pci_cfg_local_readl(device, seg, bus, dev, func, reg);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+
+	ret = peci_request_status(req);
+	if (ret)
+		goto out_req_free;
+
+	*data = peci_request_data_readl(req);
+out_req_free:
+	peci_request_free(req);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(peci_ep_pci_local_read, PECI_CPU);
+
+/**
+ * peci_mmio_read() - read 32-bit memory location using 64-bit bar offset address
+ * @device: PECI device to which request is going to be sent
+ * @bar: PCI bar
+ * @seg: PCI segment
+ * @bus: bus
+ * @dev: device
+ * @func: function
+ * @address: 64-bit MMIO address
+ * @data: where to store the read data
+ *
+ * It uses RdEndpointConfig PECI command.
+ *
+ * Return: 0 if succeeded, other values in case errors.
+ */
+int peci_mmio_read(struct peci_device *device, u8 bar, u8 seg,
+		   u8 bus, u8 dev, u8 func, u64 address, u32 *data)
+{
+	struct peci_request *req;
+	int ret;
+
+	req = peci_xfer_ep_mmio64_readl(device, bar, seg, bus, dev, func, address);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+
+	ret = peci_request_status(req);
+	if (ret)
+		goto out_req_free;
+
+	*data = peci_request_data_readl(req);
+out_req_free:
+	peci_request_free(req);
+
+	return ret;
+}
+EXPORT_SYMBOL_NS_GPL(peci_mmio_read, PECI_CPU);
+
+static const char * const peci_adev_types[] = {
+	"cputemp",
+	"dimmtemp",
+};
+
+struct peci_cpu {
+	struct peci_device *device;
+	const struct peci_device_id *id;
+};
+
+static void adev_release(struct device *dev)
+{
+	struct auxiliary_device *adev = to_auxiliary_dev(dev);
+
+	kfree(adev->name);
+	kfree(adev);
+}
+
+static struct auxiliary_device *adev_alloc(struct peci_cpu *priv, int idx)
+{
+	struct peci_controller *controller = to_peci_controller(priv->device->dev.parent);
+	struct auxiliary_device *adev;
+	const char *name;
+	int ret;
+
+	adev = kzalloc(sizeof(*adev), GFP_KERNEL);
+	if (!adev)
+		return ERR_PTR(-ENOMEM);
+
+	name = kasprintf(GFP_KERNEL, "%s.%s", peci_adev_types[idx], (const char *)priv->id->data);
+	if (!name) {
+		ret = -ENOMEM;
+		goto free_adev;
+	}
+
+	adev->name = name;
+	adev->dev.parent = &priv->device->dev;
+	adev->dev.release = adev_release;
+	adev->id = (controller->id << 16) | (priv->device->addr);
+
+	ret = auxiliary_device_init(adev);
+	if (ret)
+		goto free_name;
+
+	return adev;
+
+free_name:
+	kfree(name);
+free_adev:
+	kfree(adev);
+	return ERR_PTR(ret);
+}
+
+static void unregister_adev(void *_adev)
+{
+	struct auxiliary_device *adev = _adev;
+
+	auxiliary_device_delete(adev);
+	auxiliary_device_uninit(adev);
+}
+
+static int devm_adev_add(struct device *dev, int idx)
+{
+	struct peci_cpu *priv = dev_get_drvdata(dev);
+	struct auxiliary_device *adev;
+	int ret;
+
+	adev = adev_alloc(priv, idx);
+	if (IS_ERR(adev))
+		return PTR_ERR(adev);
+
+	ret = auxiliary_device_add(adev);
+	if (ret) {
+		auxiliary_device_uninit(adev);
+		return ret;
+	}
+
+	ret = devm_add_action_or_reset(&priv->device->dev, unregister_adev, adev);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static void peci_cpu_add_adevices(struct peci_cpu *priv)
+{
+	struct device *dev = &priv->device->dev;
+	int ret, i;
+
+	for (i = 0; i < ARRAY_SIZE(peci_adev_types); i++) {
+		ret = devm_adev_add(dev, i);
+		if (ret) {
+			dev_warn(dev, "Failed to register PECI auxiliary: %s, ret = %d\n",
+				 peci_adev_types[i], ret);
+			continue;
+		}
+	}
+}
+
+static int
+peci_cpu_probe(struct peci_device *device, const struct peci_device_id *id)
+{
+	struct device *dev = &device->dev;
+	struct peci_cpu *priv;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	dev_set_drvdata(dev, priv);
+	priv->device = device;
+	priv->id = id;
+
+	peci_cpu_add_adevices(priv);
+
+	return 0;
+}
+
+static const struct peci_device_id peci_cpu_device_ids[] = {
+	{ /* Haswell Xeon */
+		.family	= 6,
+		.model	= INTEL_FAM6_HASWELL_X,
+		.data	= "hsx",
+	},
+	{ /* Broadwell Xeon */
+		.family	= 6,
+		.model	= INTEL_FAM6_BROADWELL_X,
+		.data	= "bdx",
+	},
+	{ /* Broadwell Xeon D */
+		.family	= 6,
+		.model	= INTEL_FAM6_BROADWELL_D,
+		.data	= "bdxd",
+	},
+	{ /* Skylake Xeon */
+		.family	= 6,
+		.model	= INTEL_FAM6_SKYLAKE_X,
+		.data	= "skx",
+	},
+	{ /* Icelake Xeon */
+		.family	= 6,
+		.model	= INTEL_FAM6_ICELAKE_X,
+		.data	= "icx",
+	},
+	{ /* Icelake Xeon D */
+		.family	= 6,
+		.model	= INTEL_FAM6_ICELAKE_D,
+		.data	= "icxd",
+	},
+	{ /* Sapphire Rapids Xeon */
+		.family	= 6,
+		.model	= INTEL_FAM6_SAPPHIRERAPIDS_X,
+		.data	= "spr",
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(peci, peci_cpu_device_ids);
+
+static struct peci_driver peci_cpu_driver = {
+	.probe		= peci_cpu_probe,
+	.id_table	= peci_cpu_device_ids,
+	.driver		= {
+		.name		= "peci-cpu",
+	},
+};
+module_peci_driver(peci_cpu_driver);
+
+MODULE_AUTHOR("Iwona Winiarska <iwona.winiarska@intel.com>");
+MODULE_DESCRIPTION("PECI CPU driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PECI);
diff --git a/drivers/peci/device.c b/drivers/peci/device.c
new file mode 100644
index 0000000000..e6b0bffb14
--- /dev/null
+++ b/drivers/peci/device.c
@@ -0,0 +1,252 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2018-2021 Intel Corporation
+
+#include <linux/bitfield.h>
+#include <linux/peci.h>
+#include <linux/peci-cpu.h>
+#include <linux/slab.h>
+
+#include "internal.h"
+
+/*
+ * PECI device can be removed using sysfs, but the removal can also happen as
+ * a result of controller being removed.
+ * Mutex is used to protect PECI device from being double-deleted.
+ */
+static DEFINE_MUTEX(peci_device_del_lock);
+
+#define REVISION_NUM_MASK GENMASK(15, 8)
+static int peci_get_revision(struct peci_device *device, u8 *revision)
+{
+	struct peci_request *req;
+	u64 dib;
+
+	req = peci_xfer_get_dib(device);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+
+	/*
+	 * PECI device may be in a state where it is unable to return a proper
+	 * DIB, in which case it returns 0 as DIB value.
+	 * Let's treat this as an error to avoid carrying on with the detection
+	 * using invalid revision.
+	 */
+	dib = peci_request_dib_read(req);
+	if (dib == 0) {
+		peci_request_free(req);
+		return -EIO;
+	}
+
+	*revision = FIELD_GET(REVISION_NUM_MASK, dib);
+
+	peci_request_free(req);
+
+	return 0;
+}
+
+static int peci_get_cpu_id(struct peci_device *device, u32 *cpu_id)
+{
+	struct peci_request *req;
+	int ret;
+
+	req = peci_xfer_pkg_cfg_readl(device, PECI_PCS_PKG_ID, PECI_PKG_ID_CPU_ID);
+	if (IS_ERR(req))
+		return PTR_ERR(req);
+
+	ret = peci_request_status(req);
+	if (ret)
+		goto out_req_free;
+
+	*cpu_id = peci_request_data_readl(req);
+out_req_free:
+	peci_request_free(req);
+
+	return ret;
+}
+
+static unsigned int peci_x86_cpu_family(unsigned int sig)
+{
+	unsigned int x86;
+
+	x86 = (sig >> 8) & 0xf;
+
+	if (x86 == 0xf)
+		x86 += (sig >> 20) & 0xff;
+
+	return x86;
+}
+
+static unsigned int peci_x86_cpu_model(unsigned int sig)
+{
+	unsigned int fam, model;
+
+	fam = peci_x86_cpu_family(sig);
+
+	model = (sig >> 4) & 0xf;
+
+	if (fam >= 0x6)
+		model += ((sig >> 16) & 0xf) << 4;
+
+	return model;
+}
+
+static int peci_device_info_init(struct peci_device *device)
+{
+	u8 revision;
+	u32 cpu_id;
+	int ret;
+
+	ret = peci_get_cpu_id(device, &cpu_id);
+	if (ret)
+		return ret;
+
+	device->info.family = peci_x86_cpu_family(cpu_id);
+	device->info.model = peci_x86_cpu_model(cpu_id);
+
+	ret = peci_get_revision(device, &revision);
+	if (ret)
+		return ret;
+	device->info.peci_revision = revision;
+
+	device->info.socket_id = device->addr - PECI_BASE_ADDR;
+
+	return 0;
+}
+
+static int peci_detect(struct peci_controller *controller, u8 addr)
+{
+	/*
+	 * PECI Ping is a command encoded by tx_len = 0, rx_len = 0.
+	 * We expect correct Write FCS if the device at the target address
+	 * is able to respond.
+	 */
+	struct peci_request req = { 0 };
+	int ret;
+
+	mutex_lock(&controller->bus_lock);
+	ret = controller->ops->xfer(controller, addr, &req);
+	mutex_unlock(&controller->bus_lock);
+
+	return ret;
+}
+
+static bool peci_addr_valid(u8 addr)
+{
+	return addr >= PECI_BASE_ADDR && addr < PECI_BASE_ADDR + PECI_DEVICE_NUM_MAX;
+}
+
+static int peci_dev_exists(struct device *dev, void *data)
+{
+	struct peci_device *device = to_peci_device(dev);
+	u8 *addr = data;
+
+	if (device->addr == *addr)
+		return -EBUSY;
+
+	return 0;
+}
+
+int peci_device_create(struct peci_controller *controller, u8 addr)
+{
+	struct peci_device *device;
+	int ret;
+
+	if (!peci_addr_valid(addr))
+		return -EINVAL;
+
+	/* Check if we have already detected this device before. */
+	ret = device_for_each_child(&controller->dev, &addr, peci_dev_exists);
+	if (ret)
+		return 0;
+
+	ret = peci_detect(controller, addr);
+	if (ret) {
+		/*
+		 * Device not present or host state doesn't allow successful
+		 * detection at this time.
+		 */
+		if (ret == -EIO || ret == -ETIMEDOUT)
+			return 0;
+
+		return ret;
+	}
+
+	device = kzalloc(sizeof(*device), GFP_KERNEL);
+	if (!device)
+		return -ENOMEM;
+
+	device_initialize(&device->dev);
+
+	device->addr = addr;
+	device->dev.parent = &controller->dev;
+	device->dev.bus = &peci_bus_type;
+	device->dev.type = &peci_device_type;
+
+	ret = peci_device_info_init(device);
+	if (ret)
+		goto err_put;
+
+	ret = dev_set_name(&device->dev, "%d-%02x", controller->id, device->addr);
+	if (ret)
+		goto err_put;
+
+	ret = device_add(&device->dev);
+	if (ret)
+		goto err_put;
+
+	return 0;
+
+err_put:
+	put_device(&device->dev);
+
+	return ret;
+}
+
+void peci_device_destroy(struct peci_device *device)
+{
+	mutex_lock(&peci_device_del_lock);
+	if (!device->deleted) {
+		device_unregister(&device->dev);
+		device->deleted = true;
+	}
+	mutex_unlock(&peci_device_del_lock);
+}
+
+int __peci_driver_register(struct peci_driver *driver, struct module *owner,
+			   const char *mod_name)
+{
+	driver->driver.bus = &peci_bus_type;
+	driver->driver.owner = owner;
+	driver->driver.mod_name = mod_name;
+
+	if (!driver->probe) {
+		pr_err("peci: trying to register driver without probe callback\n");
+		return -EINVAL;
+	}
+
+	if (!driver->id_table) {
+		pr_err("peci: trying to register driver without device id table\n");
+		return -EINVAL;
+	}
+
+	return driver_register(&driver->driver);
+}
+EXPORT_SYMBOL_NS_GPL(__peci_driver_register, PECI);
+
+void peci_driver_unregister(struct peci_driver *driver)
+{
+	driver_unregister(&driver->driver);
+}
+EXPORT_SYMBOL_NS_GPL(peci_driver_unregister, PECI);
+
+static void peci_device_release(struct device *dev)
+{
+	struct peci_device *device = to_peci_device(dev);
+
+	kfree(device);
+}
+
+struct device_type peci_device_type = {
+	.groups		= peci_device_groups,
+	.release	= peci_device_release,
+};
diff --git a/drivers/peci/internal.h b/drivers/peci/internal.h
new file mode 100644
index 0000000000..9d75ea5450
--- /dev/null
+++ b/drivers/peci/internal.h
@@ -0,0 +1,136 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/* Copyright (c) 2018-2021 Intel Corporation */
+
+#ifndef __PECI_INTERNAL_H
+#define __PECI_INTERNAL_H
+
+#include <linux/device.h>
+#include <linux/types.h>
+
+struct peci_controller;
+struct attribute_group;
+struct peci_device;
+struct peci_request;
+
+/* PECI CPU address range 0x30-0x37 */
+#define PECI_BASE_ADDR		0x30
+#define PECI_DEVICE_NUM_MAX	8
+
+struct peci_request *peci_request_alloc(struct peci_device *device, u8 tx_len, u8 rx_len);
+void peci_request_free(struct peci_request *req);
+
+int peci_request_status(struct peci_request *req);
+
+u64 peci_request_dib_read(struct peci_request *req);
+s16 peci_request_temp_read(struct peci_request *req);
+
+u8 peci_request_data_readb(struct peci_request *req);
+u16 peci_request_data_readw(struct peci_request *req);
+u32 peci_request_data_readl(struct peci_request *req);
+u64 peci_request_data_readq(struct peci_request *req);
+
+struct peci_request *peci_xfer_get_dib(struct peci_device *device);
+struct peci_request *peci_xfer_get_temp(struct peci_device *device);
+
+struct peci_request *peci_xfer_pkg_cfg_readb(struct peci_device *device, u8 index, u16 param);
+struct peci_request *peci_xfer_pkg_cfg_readw(struct peci_device *device, u8 index, u16 param);
+struct peci_request *peci_xfer_pkg_cfg_readl(struct peci_device *device, u8 index, u16 param);
+struct peci_request *peci_xfer_pkg_cfg_readq(struct peci_device *device, u8 index, u16 param);
+
+struct peci_request *peci_xfer_pci_cfg_local_readb(struct peci_device *device,
+						   u8 bus, u8 dev, u8 func, u16 reg);
+struct peci_request *peci_xfer_pci_cfg_local_readw(struct peci_device *device,
+						   u8 bus, u8 dev, u8 func, u16 reg);
+struct peci_request *peci_xfer_pci_cfg_local_readl(struct peci_device *device,
+						   u8 bus, u8 dev, u8 func, u16 reg);
+
+struct peci_request *peci_xfer_ep_pci_cfg_local_readb(struct peci_device *device, u8 seg,
+						      u8 bus, u8 dev, u8 func, u16 reg);
+struct peci_request *peci_xfer_ep_pci_cfg_local_readw(struct peci_device *device, u8 seg,
+						      u8 bus, u8 dev, u8 func, u16 reg);
+struct peci_request *peci_xfer_ep_pci_cfg_local_readl(struct peci_device *device, u8 seg,
+						      u8 bus, u8 dev, u8 func, u16 reg);
+
+struct peci_request *peci_xfer_ep_pci_cfg_readb(struct peci_device *device, u8 seg,
+						u8 bus, u8 dev, u8 func, u16 reg);
+struct peci_request *peci_xfer_ep_pci_cfg_readw(struct peci_device *device, u8 seg,
+						u8 bus, u8 dev, u8 func, u16 reg);
+struct peci_request *peci_xfer_ep_pci_cfg_readl(struct peci_device *device, u8 seg,
+						u8 bus, u8 dev, u8 func, u16 reg);
+
+struct peci_request *peci_xfer_ep_mmio32_readl(struct peci_device *device, u8 bar, u8 seg,
+					       u8 bus, u8 dev, u8 func, u64 offset);
+
+struct peci_request *peci_xfer_ep_mmio64_readl(struct peci_device *device, u8 bar, u8 seg,
+					       u8 bus, u8 dev, u8 func, u64 offset);
+/**
+ * struct peci_device_id - PECI device data to match
+ * @data: pointer to driver private data specific to device
+ * @family: device family
+ * @model: device model
+ */
+struct peci_device_id {
+	const void *data;
+	u16 family;
+	u8 model;
+};
+
+extern struct device_type peci_device_type;
+extern const struct attribute_group *peci_device_groups[];
+
+int peci_device_create(struct peci_controller *controller, u8 addr);
+void peci_device_destroy(struct peci_device *device);
+
+extern struct bus_type peci_bus_type;
+extern const struct attribute_group *peci_bus_groups[];
+
+/**
+ * struct peci_driver - PECI driver
+ * @driver: inherit device driver
+ * @probe: probe callback
+ * @remove: remove callback
+ * @id_table: PECI device match table to decide which device to bind
+ */
+struct peci_driver {
+	struct device_driver driver;
+	int (*probe)(struct peci_device *device, const struct peci_device_id *id);
+	void (*remove)(struct peci_device *device);
+	const struct peci_device_id *id_table;
+};
+
+static inline struct peci_driver *to_peci_driver(struct device_driver *d)
+{
+	return container_of(d, struct peci_driver, driver);
+}
+
+int __peci_driver_register(struct peci_driver *driver, struct module *owner,
+			   const char *mod_name);
+/**
+ * peci_driver_register() - register PECI driver
+ * @driver: the driver to be registered
+ *
+ * PECI drivers that don't need to do anything special in module init should
+ * use the convenience "module_peci_driver" macro instead
+ *
+ * Return: zero on success, else a negative error code.
+ */
+#define peci_driver_register(driver) \
+	__peci_driver_register(driver, THIS_MODULE, KBUILD_MODNAME)
+void peci_driver_unregister(struct peci_driver *driver);
+
+/**
+ * module_peci_driver() - helper macro for registering a modular PECI driver
+ * @__peci_driver: peci_driver struct
+ *
+ * Helper macro for PECI drivers which do not do anything special in module
+ * init/exit. This eliminates a lot of boilerplate. Each module may only
+ * use this macro once, and calling it replaces module_init() and module_exit()
+ */
+#define module_peci_driver(__peci_driver) \
+	module_driver(__peci_driver, peci_driver_register, peci_driver_unregister)
+
+extern struct device_type peci_controller_type;
+
+int peci_controller_scan_devices(struct peci_controller *controller);
+
+#endif /* __PECI_INTERNAL_H */
diff --git a/drivers/peci/request.c b/drivers/peci/request.c
new file mode 100644
index 0000000000..8d6dd7b6b5
--- /dev/null
+++ b/drivers/peci/request.c
@@ -0,0 +1,482 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2021 Intel Corporation
+
+#include <linux/bug.h>
+#include <linux/export.h>
+#include <linux/pci.h>
+#include <linux/peci.h>
+#include <linux/slab.h>
+#include <linux/types.h>
+
+#include <asm/unaligned.h>
+
+#include "internal.h"
+
+#define PECI_GET_DIB_CMD		0xf7
+#define  PECI_GET_DIB_WR_LEN		1
+#define  PECI_GET_DIB_RD_LEN		8
+
+#define PECI_GET_TEMP_CMD		0x01
+#define  PECI_GET_TEMP_WR_LEN		1
+#define  PECI_GET_TEMP_RD_LEN		2
+
+#define PECI_RDPKGCFG_CMD		0xa1
+#define  PECI_RDPKGCFG_WR_LEN		5
+#define  PECI_RDPKGCFG_RD_LEN_BASE	1
+#define PECI_WRPKGCFG_CMD		0xa5
+#define  PECI_WRPKGCFG_WR_LEN_BASE	6
+#define  PECI_WRPKGCFG_RD_LEN		1
+
+#define PECI_RDIAMSR_CMD		0xb1
+#define  PECI_RDIAMSR_WR_LEN		5
+#define  PECI_RDIAMSR_RD_LEN		9
+#define PECI_WRIAMSR_CMD		0xb5
+#define PECI_RDIAMSREX_CMD		0xd1
+#define  PECI_RDIAMSREX_WR_LEN		6
+#define  PECI_RDIAMSREX_RD_LEN		9
+
+#define PECI_RDPCICFG_CMD		0x61
+#define  PECI_RDPCICFG_WR_LEN		6
+#define  PECI_RDPCICFG_RD_LEN		5
+#define  PECI_RDPCICFG_RD_LEN_MAX	24
+#define PECI_WRPCICFG_CMD		0x65
+
+#define PECI_RDPCICFGLOCAL_CMD			0xe1
+#define  PECI_RDPCICFGLOCAL_WR_LEN		5
+#define  PECI_RDPCICFGLOCAL_RD_LEN_BASE		1
+#define PECI_WRPCICFGLOCAL_CMD			0xe5
+#define  PECI_WRPCICFGLOCAL_WR_LEN_BASE		6
+#define  PECI_WRPCICFGLOCAL_RD_LEN		1
+
+#define PECI_ENDPTCFG_TYPE_LOCAL_PCI		0x03
+#define PECI_ENDPTCFG_TYPE_PCI			0x04
+#define PECI_ENDPTCFG_TYPE_MMIO			0x05
+#define PECI_ENDPTCFG_ADDR_TYPE_PCI		0x04
+#define PECI_ENDPTCFG_ADDR_TYPE_MMIO_D		0x05
+#define PECI_ENDPTCFG_ADDR_TYPE_MMIO_Q		0x06
+#define PECI_RDENDPTCFG_CMD			0xc1
+#define  PECI_RDENDPTCFG_PCI_WR_LEN		12
+#define  PECI_RDENDPTCFG_MMIO_WR_LEN_BASE	10
+#define  PECI_RDENDPTCFG_MMIO_D_WR_LEN		14
+#define  PECI_RDENDPTCFG_MMIO_Q_WR_LEN		18
+#define  PECI_RDENDPTCFG_RD_LEN_BASE		1
+#define PECI_WRENDPTCFG_CMD			0xc5
+#define  PECI_WRENDPTCFG_PCI_WR_LEN_BASE	13
+#define  PECI_WRENDPTCFG_MMIO_D_WR_LEN_BASE	15
+#define  PECI_WRENDPTCFG_MMIO_Q_WR_LEN_BASE	19
+#define  PECI_WRENDPTCFG_RD_LEN			1
+
+/* Device Specific Completion Code (CC) Definition */
+#define PECI_CC_SUCCESS				0x40
+#define PECI_CC_NEED_RETRY			0x80
+#define PECI_CC_OUT_OF_RESOURCE			0x81
+#define PECI_CC_UNAVAIL_RESOURCE		0x82
+#define PECI_CC_INVALID_REQ			0x90
+#define PECI_CC_MCA_ERROR			0x91
+#define PECI_CC_CATASTROPHIC_MCA_ERROR		0x93
+#define PECI_CC_FATAL_MCA_ERROR			0x94
+#define PECI_CC_PARITY_ERR_GPSB_OR_PMSB		0x98
+#define PECI_CC_PARITY_ERR_GPSB_OR_PMSB_IERR	0x9B
+#define PECI_CC_PARITY_ERR_GPSB_OR_PMSB_MCA	0x9C
+
+#define PECI_RETRY_BIT			BIT(0)
+
+#define PECI_RETRY_TIMEOUT		msecs_to_jiffies(700)
+#define PECI_RETRY_INTERVAL_MIN		msecs_to_jiffies(1)
+#define PECI_RETRY_INTERVAL_MAX		msecs_to_jiffies(128)
+
+static u8 peci_request_data_cc(struct peci_request *req)
+{
+	return req->rx.buf[0];
+}
+
+/**
+ * peci_request_status() - return -errno based on PECI completion code
+ * @req: the PECI request that contains response data with completion code
+ *
+ * It can't be used for Ping(), GetDIB() and GetTemp() - for those commands we
+ * don't expect completion code in the response.
+ *
+ * Return: -errno
+ */
+int peci_request_status(struct peci_request *req)
+{
+	u8 cc = peci_request_data_cc(req);
+
+	if (cc != PECI_CC_SUCCESS)
+		dev_dbg(&req->device->dev, "ret: %#02x\n", cc);
+
+	switch (cc) {
+	case PECI_CC_SUCCESS:
+		return 0;
+	case PECI_CC_NEED_RETRY:
+	case PECI_CC_OUT_OF_RESOURCE:
+	case PECI_CC_UNAVAIL_RESOURCE:
+		return -EAGAIN;
+	case PECI_CC_INVALID_REQ:
+		return -EINVAL;
+	case PECI_CC_MCA_ERROR:
+	case PECI_CC_CATASTROPHIC_MCA_ERROR:
+	case PECI_CC_FATAL_MCA_ERROR:
+	case PECI_CC_PARITY_ERR_GPSB_OR_PMSB:
+	case PECI_CC_PARITY_ERR_GPSB_OR_PMSB_IERR:
+	case PECI_CC_PARITY_ERR_GPSB_OR_PMSB_MCA:
+		return -EIO;
+	}
+
+	WARN_ONCE(1, "Unknown PECI completion code: %#02x\n", cc);
+
+	return -EIO;
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_status, PECI);
+
+static int peci_request_xfer(struct peci_request *req)
+{
+	struct peci_device *device = req->device;
+	struct peci_controller *controller = to_peci_controller(device->dev.parent);
+	int ret;
+
+	mutex_lock(&controller->bus_lock);
+	ret = controller->ops->xfer(controller, device->addr, req);
+	mutex_unlock(&controller->bus_lock);
+
+	return ret;
+}
+
+static int peci_request_xfer_retry(struct peci_request *req)
+{
+	long wait_interval = PECI_RETRY_INTERVAL_MIN;
+	struct peci_device *device = req->device;
+	struct peci_controller *controller = to_peci_controller(device->dev.parent);
+	unsigned long start = jiffies;
+	int ret;
+
+	/* Don't try to use it for ping */
+	if (WARN_ON(req->tx.len == 0))
+		return 0;
+
+	do {
+		ret = peci_request_xfer(req);
+		if (ret) {
+			dev_dbg(&controller->dev, "xfer error: %d\n", ret);
+			return ret;
+		}
+
+		if (peci_request_status(req) != -EAGAIN)
+			return 0;
+
+		/* Set the retry bit to indicate a retry attempt */
+		req->tx.buf[1] |= PECI_RETRY_BIT;
+
+		if (schedule_timeout_interruptible(wait_interval))
+			return -ERESTARTSYS;
+
+		wait_interval = min_t(long, wait_interval * 2, PECI_RETRY_INTERVAL_MAX);
+	} while (time_before(jiffies, start + PECI_RETRY_TIMEOUT));
+
+	dev_dbg(&controller->dev, "request timed out\n");
+
+	return -ETIMEDOUT;
+}
+
+/**
+ * peci_request_alloc() - allocate &struct peci_requests
+ * @device: PECI device to which request is going to be sent
+ * @tx_len: TX length
+ * @rx_len: RX length
+ *
+ * Return: A pointer to a newly allocated &struct peci_request on success or NULL otherwise.
+ */
+struct peci_request *peci_request_alloc(struct peci_device *device, u8 tx_len, u8 rx_len)
+{
+	struct peci_request *req;
+
+	/*
+	 * TX and RX buffers are fixed length members of peci_request, this is
+	 * just a warn for developers to make sure to expand the buffers (or
+	 * change the allocation method) if we go over the current limit.
+	 */
+	if (WARN_ON_ONCE(tx_len > PECI_REQUEST_MAX_BUF_SIZE || rx_len > PECI_REQUEST_MAX_BUF_SIZE))
+		return NULL;
+	/*
+	 * PECI controllers that we are using now don't support DMA, this
+	 * should be converted to DMA API once support for controllers that do
+	 * allow it is added to avoid an extra copy.
+	 */
+	req = kzalloc(sizeof(*req), GFP_KERNEL);
+	if (!req)
+		return NULL;
+
+	req->device = device;
+	req->tx.len = tx_len;
+	req->rx.len = rx_len;
+
+	return req;
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_alloc, PECI);
+
+/**
+ * peci_request_free() - free peci_request
+ * @req: the PECI request to be freed
+ */
+void peci_request_free(struct peci_request *req)
+{
+	kfree(req);
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_free, PECI);
+
+struct peci_request *peci_xfer_get_dib(struct peci_device *device)
+{
+	struct peci_request *req;
+	int ret;
+
+	req = peci_request_alloc(device, PECI_GET_DIB_WR_LEN, PECI_GET_DIB_RD_LEN);
+	if (!req)
+		return ERR_PTR(-ENOMEM);
+
+	req->tx.buf[0] = PECI_GET_DIB_CMD;
+
+	ret = peci_request_xfer(req);
+	if (ret) {
+		peci_request_free(req);
+		return ERR_PTR(ret);
+	}
+
+	return req;
+}
+EXPORT_SYMBOL_NS_GPL(peci_xfer_get_dib, PECI);
+
+struct peci_request *peci_xfer_get_temp(struct peci_device *device)
+{
+	struct peci_request *req;
+	int ret;
+
+	req = peci_request_alloc(device, PECI_GET_TEMP_WR_LEN, PECI_GET_TEMP_RD_LEN);
+	if (!req)
+		return ERR_PTR(-ENOMEM);
+
+	req->tx.buf[0] = PECI_GET_TEMP_CMD;
+
+	ret = peci_request_xfer(req);
+	if (ret) {
+		peci_request_free(req);
+		return ERR_PTR(ret);
+	}
+
+	return req;
+}
+EXPORT_SYMBOL_NS_GPL(peci_xfer_get_temp, PECI);
+
+static struct peci_request *
+__pkg_cfg_read(struct peci_device *device, u8 index, u16 param, u8 len)
+{
+	struct peci_request *req;
+	int ret;
+
+	req = peci_request_alloc(device, PECI_RDPKGCFG_WR_LEN, PECI_RDPKGCFG_RD_LEN_BASE + len);
+	if (!req)
+		return ERR_PTR(-ENOMEM);
+
+	req->tx.buf[0] = PECI_RDPKGCFG_CMD;
+	req->tx.buf[1] = 0;
+	req->tx.buf[2] = index;
+	put_unaligned_le16(param, &req->tx.buf[3]);
+
+	ret = peci_request_xfer_retry(req);
+	if (ret) {
+		peci_request_free(req);
+		return ERR_PTR(ret);
+	}
+
+	return req;
+}
+
+static u32 __get_pci_addr(u8 bus, u8 dev, u8 func, u16 reg)
+{
+	return reg | PCI_DEVID(bus, PCI_DEVFN(dev, func)) << 12;
+}
+
+static struct peci_request *
+__pci_cfg_local_read(struct peci_device *device, u8 bus, u8 dev, u8 func, u16 reg, u8 len)
+{
+	struct peci_request *req;
+	u32 pci_addr;
+	int ret;
+
+	req = peci_request_alloc(device, PECI_RDPCICFGLOCAL_WR_LEN,
+				 PECI_RDPCICFGLOCAL_RD_LEN_BASE + len);
+	if (!req)
+		return ERR_PTR(-ENOMEM);
+
+	pci_addr = __get_pci_addr(bus, dev, func, reg);
+
+	req->tx.buf[0] = PECI_RDPCICFGLOCAL_CMD;
+	req->tx.buf[1] = 0;
+	put_unaligned_le24(pci_addr, &req->tx.buf[2]);
+
+	ret = peci_request_xfer_retry(req);
+	if (ret) {
+		peci_request_free(req);
+		return ERR_PTR(ret);
+	}
+
+	return req;
+}
+
+static struct peci_request *
+__ep_pci_cfg_read(struct peci_device *device, u8 msg_type, u8 seg,
+		  u8 bus, u8 dev, u8 func, u16 reg, u8 len)
+{
+	struct peci_request *req;
+	u32 pci_addr;
+	int ret;
+
+	req = peci_request_alloc(device, PECI_RDENDPTCFG_PCI_WR_LEN,
+				 PECI_RDENDPTCFG_RD_LEN_BASE + len);
+	if (!req)
+		return ERR_PTR(-ENOMEM);
+
+	pci_addr = __get_pci_addr(bus, dev, func, reg);
+
+	req->tx.buf[0] = PECI_RDENDPTCFG_CMD;
+	req->tx.buf[1] = 0;
+	req->tx.buf[2] = msg_type;
+	req->tx.buf[3] = 0;
+	req->tx.buf[4] = 0;
+	req->tx.buf[5] = 0;
+	req->tx.buf[6] = PECI_ENDPTCFG_ADDR_TYPE_PCI;
+	req->tx.buf[7] = seg; /* PCI Segment */
+	put_unaligned_le32(pci_addr, &req->tx.buf[8]);
+
+	ret = peci_request_xfer_retry(req);
+	if (ret) {
+		peci_request_free(req);
+		return ERR_PTR(ret);
+	}
+
+	return req;
+}
+
+static struct peci_request *
+__ep_mmio_read(struct peci_device *device, u8 bar, u8 addr_type, u8 seg,
+	       u8 bus, u8 dev, u8 func, u64 offset, u8 tx_len, u8 len)
+{
+	struct peci_request *req;
+	int ret;
+
+	req = peci_request_alloc(device, tx_len, PECI_RDENDPTCFG_RD_LEN_BASE + len);
+	if (!req)
+		return ERR_PTR(-ENOMEM);
+
+	req->tx.buf[0] = PECI_RDENDPTCFG_CMD;
+	req->tx.buf[1] = 0;
+	req->tx.buf[2] = PECI_ENDPTCFG_TYPE_MMIO;
+	req->tx.buf[3] = 0; /* Endpoint ID */
+	req->tx.buf[4] = 0; /* Reserved */
+	req->tx.buf[5] = bar;
+	req->tx.buf[6] = addr_type;
+	req->tx.buf[7] = seg; /* PCI Segment */
+	req->tx.buf[8] = PCI_DEVFN(dev, func);
+	req->tx.buf[9] = bus; /* PCI Bus */
+
+	if (addr_type == PECI_ENDPTCFG_ADDR_TYPE_MMIO_D)
+		put_unaligned_le32(offset, &req->tx.buf[10]);
+	else
+		put_unaligned_le64(offset, &req->tx.buf[10]);
+
+	ret = peci_request_xfer_retry(req);
+	if (ret) {
+		peci_request_free(req);
+		return ERR_PTR(ret);
+	}
+
+	return req;
+}
+
+u8 peci_request_data_readb(struct peci_request *req)
+{
+	return req->rx.buf[1];
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_data_readb, PECI);
+
+u16 peci_request_data_readw(struct peci_request *req)
+{
+	return get_unaligned_le16(&req->rx.buf[1]);
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_data_readw, PECI);
+
+u32 peci_request_data_readl(struct peci_request *req)
+{
+	return get_unaligned_le32(&req->rx.buf[1]);
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_data_readl, PECI);
+
+u64 peci_request_data_readq(struct peci_request *req)
+{
+	return get_unaligned_le64(&req->rx.buf[1]);
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_data_readq, PECI);
+
+u64 peci_request_dib_read(struct peci_request *req)
+{
+	return get_unaligned_le64(&req->rx.buf[0]);
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_dib_read, PECI);
+
+s16 peci_request_temp_read(struct peci_request *req)
+{
+	return get_unaligned_le16(&req->rx.buf[0]);
+}
+EXPORT_SYMBOL_NS_GPL(peci_request_temp_read, PECI);
+
+#define __read_pkg_config(x, type) \
+struct peci_request *peci_xfer_pkg_cfg_##x(struct peci_device *device, u8 index, u16 param) \
+{ \
+	return __pkg_cfg_read(device, index, param, sizeof(type)); \
+} \
+EXPORT_SYMBOL_NS_GPL(peci_xfer_pkg_cfg_##x, PECI)
+
+__read_pkg_config(readb, u8);
+__read_pkg_config(readw, u16);
+__read_pkg_config(readl, u32);
+__read_pkg_config(readq, u64);
+
+#define __read_pci_config_local(x, type) \
+struct peci_request * \
+peci_xfer_pci_cfg_local_##x(struct peci_device *device, u8 bus, u8 dev, u8 func, u16 reg) \
+{ \
+	return __pci_cfg_local_read(device, bus, dev, func, reg, sizeof(type)); \
+} \
+EXPORT_SYMBOL_NS_GPL(peci_xfer_pci_cfg_local_##x, PECI)
+
+__read_pci_config_local(readb, u8);
+__read_pci_config_local(readw, u16);
+__read_pci_config_local(readl, u32);
+
+#define __read_ep_pci_config(x, msg_type, type) \
+struct peci_request * \
+peci_xfer_ep_pci_cfg_##x(struct peci_device *device, u8 seg, u8 bus, u8 dev, u8 func, u16 reg) \
+{ \
+	return __ep_pci_cfg_read(device, msg_type, seg, bus, dev, func, reg, sizeof(type)); \
+} \
+EXPORT_SYMBOL_NS_GPL(peci_xfer_ep_pci_cfg_##x, PECI)
+
+__read_ep_pci_config(local_readb, PECI_ENDPTCFG_TYPE_LOCAL_PCI, u8);
+__read_ep_pci_config(local_readw, PECI_ENDPTCFG_TYPE_LOCAL_PCI, u16);
+__read_ep_pci_config(local_readl, PECI_ENDPTCFG_TYPE_LOCAL_PCI, u32);
+__read_ep_pci_config(readb, PECI_ENDPTCFG_TYPE_PCI, u8);
+__read_ep_pci_config(readw, PECI_ENDPTCFG_TYPE_PCI, u16);
+__read_ep_pci_config(readl, PECI_ENDPTCFG_TYPE_PCI, u32);
+
+#define __read_ep_mmio(x, y, addr_type, type1, type2) \
+struct peci_request *peci_xfer_ep_mmio##y##_##x(struct peci_device *device, u8 bar, u8 seg, \
+					   u8 bus, u8 dev, u8 func, u64 offset) \
+{ \
+	return __ep_mmio_read(device, bar, addr_type, seg, bus, dev, func, \
+			      offset, PECI_RDENDPTCFG_MMIO_WR_LEN_BASE + sizeof(type1), \
+			      sizeof(type2)); \
+} \
+EXPORT_SYMBOL_NS_GPL(peci_xfer_ep_mmio##y##_##x, PECI)
+
+__read_ep_mmio(readl, 32, PECI_ENDPTCFG_ADDR_TYPE_MMIO_D, u32, u32);
+__read_ep_mmio(readl, 64, PECI_ENDPTCFG_ADDR_TYPE_MMIO_Q, u64, u32);
diff --git a/drivers/peci/sysfs.c b/drivers/peci/sysfs.c
new file mode 100644
index 0000000000..c042440757
--- /dev/null
+++ b/drivers/peci/sysfs.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0-only
+// Copyright (c) 2021 Intel Corporation
+
+#include <linux/device.h>
+#include <linux/kernel.h>
+#include <linux/peci.h>
+
+#include "internal.h"
+
+static int rescan_controller(struct device *dev, void *data)
+{
+	if (dev->type != &peci_controller_type)
+		return 0;
+
+	return peci_controller_scan_devices(to_peci_controller(dev));
+}
+
+static ssize_t rescan_store(const struct bus_type *bus, const char *buf, size_t count)
+{
+	bool res;
+	int ret;
+
+	ret = kstrtobool(buf, &res);
+	if (ret)
+		return ret;
+
+	if (!res)
+		return count;
+
+	ret = bus_for_each_dev(&peci_bus_type, NULL, NULL, rescan_controller);
+	if (ret)
+		return ret;
+
+	return count;
+}
+static BUS_ATTR_WO(rescan);
+
+static struct attribute *peci_bus_attrs[] = {
+	&bus_attr_rescan.attr,
+	NULL
+};
+
+static const struct attribute_group peci_bus_group = {
+	.attrs = peci_bus_attrs,
+};
+
+const struct attribute_group *peci_bus_groups[] = {
+	&peci_bus_group,
+	NULL
+};
+
+static ssize_t remove_store(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct peci_device *device = to_peci_device(dev);
+	bool res;
+	int ret;
+
+	ret = kstrtobool(buf, &res);
+	if (ret)
+		return ret;
+
+	if (res && device_remove_file_self(dev, attr))
+		peci_device_destroy(device);
+
+	return count;
+}
+static DEVICE_ATTR_IGNORE_LOCKDEP(remove, 0200, NULL, remove_store);
+
+static struct attribute *peci_device_attrs[] = {
+	&dev_attr_remove.attr,
+	NULL
+};
+
+static const struct attribute_group peci_device_group = {
+	.attrs = peci_device_attrs,
+};
+
+const struct attribute_group *peci_device_groups[] = {
+	&peci_device_group,
+	NULL
+};