peci: Add peci-aspeed controller driver
authorJae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Tue, 8 Feb 2022 15:36:31 +0000 (16:36 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 9 Feb 2022 07:04:43 +0000 (08:04 +0100)
ASPEED AST24xx/AST25xx/AST26xx SoCs support the PECI electrical
interface (a.k.a PECI wire) that provides a communication channel with
Intel processors.
This driver allows BMC to discover devices connected to it and
communicate with them using PECI protocol.

Co-developed-by: Iwona Winiarska <iwona.winiarska@intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Acked-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>
Link: https://lore.kernel.org/r/20220208153639.255278-6-iwona.winiarska@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
MAINTAINERS
drivers/peci/Kconfig
drivers/peci/Makefile
drivers/peci/controller/Kconfig [new file with mode: 0644]
drivers/peci/controller/Makefile [new file with mode: 0644]
drivers/peci/controller/peci-aspeed.c [new file with mode: 0644]

index 0fd6c9f..b8511e7 100644 (file)
@@ -2986,6 +2986,14 @@ S:       Maintained
 F:     Documentation/devicetree/bindings/net/asix,ax88796c.yaml
 F:     drivers/net/ethernet/asix/ax88796c_*
 
+ASPEED PECI CONTROLLER
+M:     Iwona Winiarska <iwona.winiarska@intel.com>
+L:     linux-aspeed@lists.ozlabs.org (moderated for non-subscribers)
+L:     openbmc@lists.ozlabs.org (moderated for non-subscribers)
+S:     Supported
+F:     Documentation/devicetree/bindings/peci/peci-aspeed.yaml
+F:     drivers/peci/controller/peci-aspeed.c
+
 ASPEED PINCTRL DRIVERS
 M:     Andrew Jeffery <andrew@aj.id.au>
 L:     linux-aspeed@lists.ozlabs.org (moderated for non-subscribers)
index 71a4ad8..99279df 100644 (file)
@@ -13,3 +13,9 @@ menuconfig PECI
 
          This support is also available as a module. If so, the module
          will be called peci.
+
+if PECI
+
+source "drivers/peci/controller/Kconfig"
+
+endif # PECI
index e789a35..926d8df 100644 (file)
@@ -3,3 +3,6 @@
 # Core functionality
 peci-y := core.o
 obj-$(CONFIG_PECI) += peci.o
+
+# Hardware specific bus drivers
+obj-y += controller/
diff --git a/drivers/peci/controller/Kconfig b/drivers/peci/controller/Kconfig
new file mode 100644 (file)
index 0000000..2fc5e2a
--- /dev/null
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+config PECI_ASPEED
+       tristate "ASPEED PECI support"
+       depends on ARCH_ASPEED || COMPILE_TEST
+       depends on OF
+       depends on HAS_IOMEM
+       depends on COMMON_CLK
+       help
+         This option enables PECI controller driver for ASPEED AST2400,
+         AST2500 and AST2600 SoCs. It allows BMC to discover devices
+         connected to it, and communicate with them using PECI protocol.
+
+         Say Y here if your system runs on ASPEED SoC and you are using it
+         as BMC for Intel platform.
+
+         This driver can also be built as a module. If so, the module will
+         be called peci-aspeed.
diff --git a/drivers/peci/controller/Makefile b/drivers/peci/controller/Makefile
new file mode 100644 (file)
index 0000000..022c28e
--- /dev/null
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_PECI_ASPEED)      += peci-aspeed.o
diff --git a/drivers/peci/controller/peci-aspeed.c b/drivers/peci/controller/peci-aspeed.c
new file mode 100644 (file)
index 0000000..1925ddc
--- /dev/null
@@ -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 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)
+               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);