[PATCH net-next] misc: Add Renesas Synchronization Management Unit (SMU) support

[<min.li.xe@renesas.com>]

From: Min Li <min.li.xe@renesas.com>

This driver supports 1588 related functions of ClockMatrix(TM)
and 82P33xxx families of timing and synchronization devices. The
supported functons are:

- set combomode
- get dpll's state
- get dpll's ffo

Please note that this driver needs to work with rsmu mfd driver
to access SMU through I2C/SPI.

Signed-off-by: Min Li <min.li.xe@renesas.com>
---
 drivers/misc/Kconfig      |   7 +
 drivers/misc/Makefile     |   3 +
 drivers/misc/rsmu_cdev.c  | 430 ++++++++++++++++++++++++++++++++++++++++++++++
 drivers/misc/rsmu_cdev.h  |  75 ++++++++
 drivers/misc/rsmu_cm.c    | 214 +++++++++++++++++++++++
 drivers/misc/rsmu_sabre.c | 153 +++++++++++++++++
 include/uapi/linux/rsmu.h |  61 +++++++
 7 files changed, 943 insertions(+)
 create mode 100644 drivers/misc/rsmu_cdev.c
 create mode 100644 drivers/misc/rsmu_cdev.h
 create mode 100644 drivers/misc/rsmu_cm.c
 create mode 100644 drivers/misc/rsmu_sabre.c
 create mode 100644 include/uapi/linux/rsmu.h

diff --git a/drivers/misc/Kconfig b/drivers/misc/Kconfig
index fafa8b0..2ba5070 100644
--- a/drivers/misc/Kconfig
+++ b/drivers/misc/Kconfig
@@ -466,6 +466,13 @@ config HISI_HIKEY_USB
 	  switching between the dual-role USB-C port and the USB-A host ports
 	  using only one USB controller.
 
+config RSMU
+	tristate "Renesas Synchronization Management Unit (SMU)"
+	depends on MFD_RSMU_I2C || MFD_RSMU_SPI
+	help
+	  This driver provides support for Renesas SMU,
+	  such as Clockmatrix and 82P33XXX series.
+
 source "drivers/misc/c2port/Kconfig"
 source "drivers/misc/eeprom/Kconfig"
 source "drivers/misc/cb710/Kconfig"
diff --git a/drivers/misc/Makefile b/drivers/misc/Makefile
index d23231e..3054c0d 100644
--- a/drivers/misc/Makefile
+++ b/drivers/misc/Makefile
@@ -57,3 +57,6 @@ obj-$(CONFIG_HABANA_AI)		+= habanalabs/
 obj-$(CONFIG_UACCE)		+= uacce/
 obj-$(CONFIG_XILINX_SDFEC)	+= xilinx_sdfec.o
 obj-$(CONFIG_HISI_HIKEY_USB)	+= hisi_hikey_usb.o
+
+rsmu-objs			:= rsmu_cdev.o rsmu_cm.o rsmu_sabre.o
+obj-$(CONFIG_RSMU)		+= rsmu.o
diff --git a/drivers/misc/rsmu_cdev.c b/drivers/misc/rsmu_cdev.c
new file mode 100644
index 0000000..35c1f38
--- /dev/null
+++ b/drivers/misc/rsmu_cdev.c
@@ -0,0 +1,430 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * This driver is developed for the IDT ClockMatrix(TM) and 82P33xxx families of
+ * timing and synchronization devices. It exposes a char device interface in
+ * sysfs and supports file operations like  open(), close() and ioctl().
+ *
+ * Copyright (C) 2019 Integrated Device Technology, Inc., a Renesas Company.
+ */
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/uaccess.h>
+#include <linux/mfd/rsmu.h>
+#include <uapi/linux/rsmu.h>
+
+#include "rsmu_cdev.h"
+
+#define DRIVER_NAME	"rsmu"
+#define DRIVER_MAX_DEV	BIT(MINORBITS)
+
+static struct class *rsmu_class;
+static dev_t rsmu_cdevt;
+static u8 scsr_page;
+
+static int
+rsmu_set_combomode(struct rsmu_cdev *rsmu, void __user *arg)
+{
+	struct rsmu_combomode mode;
+	int err;
+
+	if (copy_from_user(&mode, arg, sizeof(mode)))
+		return -EFAULT;
+
+	mutex_lock(rsmu->lock);
+	switch (rsmu->type) {
+	case RSMU_CM:
+		err = rsmu_cm_set_combomode(rsmu, mode.dpll, mode.mode);
+		break;
+	case RSMU_SABRE:
+		err = rsmu_sabre_set_combomode(rsmu, mode.dpll, mode.mode);
+		break;
+	default:
+		err = -EINVAL;
+	}
+	mutex_unlock(rsmu->lock);
+
+	return err;
+}
+
+static int
+rsmu_get_dpll_state(struct rsmu_cdev *rsmu, void __user *arg)
+{
+	struct rsmu_get_state state_request;
+	u8 state;
+	int err;
+
+	if (copy_from_user(&state_request, arg, sizeof(state_request)))
+		return -EFAULT;
+
+	mutex_lock(rsmu->lock);
+	switch (rsmu->type) {
+	case RSMU_CM:
+		err = rsmu_cm_get_dpll_state(rsmu, state_request.dpll, &state);
+		break;
+	case RSMU_SABRE:
+		err = rsmu_sabre_get_dpll_state(rsmu, state_request.dpll,
+						&state);
+		break;
+	default:
+		err = -EINVAL;
+	}
+	mutex_unlock(rsmu->lock);
+
+	state_request.state = state;
+	if (copy_to_user(arg, &state_request, sizeof(state_request)))
+		return -EFAULT;
+
+	return err;
+}
+
+static int
+rsmu_get_dpll_ffo(struct rsmu_cdev *rsmu, void __user *arg)
+{
+	struct rsmu_get_ffo ffo_request;
+	int err;
+
+	if (copy_from_user(&ffo_request, arg, sizeof(ffo_request)))
+		return -EFAULT;
+
+	mutex_lock(rsmu->lock);
+	switch (rsmu->type) {
+	case RSMU_CM:
+		err = rsmu_cm_get_dpll_ffo(rsmu, ffo_request.dpll,
+					   &ffo_request);
+		break;
+	case RSMU_SABRE:
+		err = rsmu_sabre_get_dpll_ffo(rsmu, ffo_request.dpll,
+					      &ffo_request);
+		break;
+	default:
+		err = -EINVAL;
+	}
+	mutex_unlock(rsmu->lock);
+
+	if (copy_to_user(arg, &ffo_request, sizeof(ffo_request)))
+		return -EFAULT;
+
+	return err;
+}
+
+static ssize_t scsr_show_regs_show(struct device *dev,
+				   struct device_attribute *attr, char *page)
+{
+	struct rsmu_cdev *rsmu = dev_get_drvdata(dev);
+	char *fmt = "%04x:%02x %02x %02x %02x %02x %02x %02x %02x\n";
+	int cnt = 0;
+	u8 regs[256];
+	u16 start;
+	int rows;
+	int row;
+	int err;
+
+	mutex_lock(rsmu->lock);
+	if (rsmu->type == RSMU_CM) {
+		rows = 32;
+		start = 0xc000 + ((u16)scsr_page << 8);
+		if (scsr_page >= 16)
+			err = -EINVAL;
+		else
+			err = rsmu_read(rsmu->mfd, start, regs, 256);
+	} else if (rsmu->type == RSMU_SABRE) {
+		rows = 16;
+		start = (u16)scsr_page << 7;
+		if (scsr_page >= 7)
+			err = -EINVAL;
+		else
+			err = rsmu_read(rsmu->mfd, start, regs, 128);
+
+	} else
+		err = -EINVAL;
+	mutex_unlock(rsmu->lock);
+
+	if (err)
+		return err;
+
+	for (row = 0; row < rows; row++) {
+		u8 index = row * 8;
+
+		cnt += snprintf(page + cnt, PAGE_SIZE - cnt - 1, fmt,
+				start + index, regs[index], regs[index + 1],
+				regs[index + 2], regs[index + 3],
+				regs[index + 4], regs[index + 5],
+				regs[index + 6], regs[index + 7]);
+	}
+
+	return cnt;
+}
+static DEVICE_ATTR_RO(scsr_show_regs);
+
+static ssize_t scsr_set_page_store(struct device *dev,
+				   struct device_attribute *attr,
+				   const char *buf, size_t count)
+{
+	struct rsmu_cdev *rsmu = dev_get_drvdata(dev);
+	u8 page;
+	u8 max;
+
+	if (kstrtou8(buf, 10, &page) < 0)
+		return -EINVAL;
+
+	if (rsmu->type == RSMU_CM)
+		max = 16;
+	else if (rsmu->type == RSMU_SABRE)
+		max = 7;
+	else
+		return -EINVAL;
+
+	if (page >= max)
+		return -EINVAL;
+
+	mutex_lock(rsmu->lock);
+	scsr_page = page;
+	mutex_unlock(rsmu->lock);
+
+	return count;
+}
+static DEVICE_ATTR_WO(scsr_set_page);
+
+static struct attribute *rsmu_attrs[] = {
+	&dev_attr_scsr_set_page.attr,
+	&dev_attr_scsr_show_regs.attr,
+	NULL
+};
+
+static const struct attribute_group rsmu_group = {
+	.attrs = rsmu_attrs
+};
+
+static int
+rsmu_open(struct inode *iptr, struct file *fptr)
+{
+	struct rsmu_cdev *rsmu;
+
+	rsmu = container_of(iptr->i_cdev, struct rsmu_cdev, rsmu_cdev);
+	if (!rsmu)
+		return -EAGAIN;
+
+	/* Only one open per device at a time */
+	if (!atomic_dec_and_test(&rsmu->open_count)) {
+		atomic_inc(&rsmu->open_count);
+		return -EBUSY;
+	}
+
+	fptr->private_data = rsmu;
+	return 0;
+}
+
+static int
+rsmu_release(struct inode *iptr, struct file *fptr)
+{
+	struct rsmu_cdev *rsmu;
+
+	rsmu = container_of(iptr->i_cdev, struct rsmu_cdev, rsmu_cdev);
+	if (!rsmu)
+		return -EAGAIN;
+
+	atomic_inc(&rsmu->open_count);
+	return 0;
+}
+
+static long
+rsmu_ioctl(struct file *fptr, unsigned int cmd, unsigned long data)
+{
+	struct rsmu_cdev *rsmu = fptr->private_data;
+	void __user *arg = (void __user *)data;
+	int err = 0;
+
+	if (!rsmu)
+		return -EINVAL;
+
+	switch (cmd) {
+	case RSMU_SET_COMBOMODE:
+		err = rsmu_set_combomode(rsmu, arg);
+		break;
+	case RSMU_GET_STATE:
+		err = rsmu_get_dpll_state(rsmu, arg);
+		break;
+	case RSMU_GET_FFO:
+		err = rsmu_get_dpll_ffo(rsmu, arg);
+		break;
+	default:
+		/* Should not get here */
+		dev_err(rsmu->dev, "Undefined RSMU IOCTL");
+		err = -EINVAL;
+		break;
+	}
+
+	return err;
+}
+
+static const struct file_operations rsmu_fops = {
+	.owner = THIS_MODULE,
+	.open = rsmu_open,
+	.release = rsmu_release,
+	.unlocked_ioctl = rsmu_ioctl,
+};
+
+static int
+rsmu_probe(struct platform_device *pdev)
+{
+	struct rsmu_pdata *pdata = dev_get_platdata(&pdev->dev);
+	struct rsmu_cdev *rsmu;
+	struct device *rsmu_cdev;
+	int err;
+
+	rsmu = devm_kzalloc(&pdev->dev, sizeof(*rsmu), GFP_KERNEL);
+	if (!rsmu)
+		return -ENOMEM;
+
+	rsmu->dev = &pdev->dev;
+	rsmu->mfd = pdev->dev.parent;
+	rsmu->type = pdata->type;
+	rsmu->lock = pdata->lock;
+	rsmu->index = pdata->index;
+
+	/* Save driver private data */
+	platform_set_drvdata(pdev, rsmu);
+
+	cdev_init(&rsmu->rsmu_cdev, &rsmu_fops);
+	rsmu->rsmu_cdev.owner = THIS_MODULE;
+	err = cdev_add(&rsmu->rsmu_cdev,
+		       MKDEV(MAJOR(rsmu_cdevt), 0), 1);
+	if (err < 0) {
+		dev_err(rsmu->dev, "cdev_add failed");
+		err = -EIO;
+		goto err_rsmu_dev;
+	}
+
+	if (!rsmu_class) {
+		err = -EIO;
+		dev_err(rsmu->dev, "rsmu class not created correctly");
+		goto err_rsmu_cdev;
+	}
+
+	rsmu_cdev = device_create(rsmu_class, rsmu->dev,
+				   MKDEV(MAJOR(rsmu_cdevt), 0),
+				   rsmu, "rsmu%d", rsmu->index);
+	if (IS_ERR(rsmu_cdev)) {
+		dev_err(rsmu->dev, "unable to create char device");
+		err = PTR_ERR(rsmu_cdev);
+		goto err_rsmu_cdev;
+	}
+
+	err = sysfs_create_group(&rsmu_cdev->kobj, &rsmu_group);
+	if (err) {
+		dev_err(rsmu->dev, "sysfs_create_group failed\n");
+		goto err_rsmu_cdev;
+	}
+
+	atomic_set(&rsmu->open_count, 1);
+	dev_info(rsmu->dev, "Probe SMU type %d Successful\n", rsmu->type);
+	return 0;
+
+	/* Failure cleanup */
+err_rsmu_cdev:
+	cdev_del(&rsmu->rsmu_cdev);
+err_rsmu_dev:
+	return err;
+}
+
+static int
+rsmu_remove(struct platform_device *pdev)
+{
+	struct rsmu_cdev *rsmu;
+	struct device *dev = &pdev->dev;
+
+	rsmu = platform_get_drvdata(pdev);
+	if (!rsmu)
+		return -ENODEV;
+
+	if (!rsmu_class) {
+		dev_err(dev, "rsmu_class is NULL");
+		return -EIO;
+	}
+
+	device_destroy(rsmu_class, MKDEV(MAJOR(rsmu_cdevt), 0));
+	cdev_del(&rsmu->rsmu_cdev);
+
+	return 0;
+}
+
+static const struct platform_device_id rsmu_id_table[] = {
+	{ "rsmu-cdev0", },
+	{ "rsmu-cdev1", },
+	{ "rsmu-cdev2", },
+	{ "rsmu-cdev3", },
+	{},
+};
+MODULE_DEVICE_TABLE(platform, rsmu_id_table);
+
+static const struct of_device_id rsmu_of_match[] = {
+	{ .compatible = "renesas,rsmu-cdev0", },
+	{ .compatible = "renesas,rsmu-cdev1", },
+	{ .compatible = "renesas,rsmu-cdev2", },
+	{ .compatible = "renesas,rsmu-cdev3", },
+	{ /* end of table */ }
+};
+MODULE_DEVICE_TABLE(of, rsmu_of_match);
+
+static struct platform_driver rsmu_driver = {
+	.driver = {
+		.name = DRIVER_NAME,
+		.of_match_table = rsmu_of_match,
+	},
+	.probe = rsmu_probe,
+	.remove =  rsmu_remove,
+	.id_table = rsmu_id_table,
+};
+
+static int __init rsmu_init(void)
+{
+	int err;
+
+	rsmu_class = class_create(THIS_MODULE, DRIVER_NAME);
+	if (IS_ERR(rsmu_class)) {
+		err = PTR_ERR(rsmu_class);
+		pr_err("%s : Unable to register rsmu class", __func__);
+		return err;
+	}
+
+	err = alloc_chrdev_region(&rsmu_cdevt, 0, DRIVER_MAX_DEV, DRIVER_NAME);
+	if (err < 0) {
+		pr_err("%s : Unable to get major number", __func__);
+		goto err_rsmu_class;
+	}
+
+	err = platform_driver_register(&rsmu_driver);
+	if (err < 0) {
+		pr_err("%s Unabled to register %s driver",
+		       __func__, DRIVER_NAME);
+		goto err_rsmu_drv;
+	}
+	return 0;
+
+	/* Error Path */
+err_rsmu_drv:
+	unregister_chrdev_region(rsmu_cdevt, DRIVER_MAX_DEV);
+err_rsmu_class:
+	class_destroy(rsmu_class);
+	return err;
+}
+
+static void __exit rsmu_exit(void)
+{
+	platform_driver_unregister(&rsmu_driver);
+	unregister_chrdev_region(rsmu_cdevt, DRIVER_MAX_DEV);
+	class_destroy(rsmu_class);
+	rsmu_class = NULL;
+}
+
+module_init(rsmu_init);
+module_exit(rsmu_exit);
+
+MODULE_DESCRIPTION("Renesas SMU character device driver");
+MODULE_LICENSE("GPL");
diff --git a/drivers/misc/rsmu_cdev.h b/drivers/misc/rsmu_cdev.h
new file mode 100644
index 0000000..4b38790a
--- /dev/null
+++ b/drivers/misc/rsmu_cdev.h
@@ -0,0 +1,75 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * This driver is developed for the IDT ClockMatrix(TM) of
+ * timing and synchronization devices.
+ *
+ * Copyright (C) 2019 Integrated Device Technology, Inc., a Renesas Company.
+ */
+#ifndef __LINUX_RSMU_CDEV_H
+#define __LINUX_RSMU_CDEV_H
+
+#include <linux/cdev.h>
+
+/**
+ * struct rsmu_cdev - Driver data for RSMU character device
+ * @dev: pointer to platform device
+ * @mfd: pointer to MFD device
+ * @open_count: Count of char device being opened
+ * @rsmu_cdev: Character device handle
+ * @lock: Mutex to protect operations from being interrupted
+ */
+struct rsmu_cdev {
+	struct device *dev;
+	struct device *mfd;
+	struct cdev rsmu_cdev;
+	struct mutex *lock;
+	enum rsmu_type type;
+	atomic_t open_count;
+	u8 index;
+};
+
+/**
+ * Enumerated type listing DPLL combination modes
+ */
+enum rsmu_dpll_combomode {
+	E_COMBOMODE_CURRENT = 0,
+	E_COMBOMODE_FASTAVG,
+	E_COMBOMODE_SLOWAVG,
+	E_COMBOMODE_HOLDOVER,
+	E_COMBOMODE_MAX,
+};
+
+/**
+ * An id used to identify the respective child class states.
+ */
+enum rsmu_class_state {
+	E_SRVLOINITIALSTATE = 0,
+	E_SRVLOUNQUALIFIEDSTATE = 1,
+	E_SRVLOLOCKACQSTATE = 2,
+	E_SRVLOFREQUENCYLOCKEDSTATE = 3,
+	E_SRVLOTIMELOCKEDSTATE = 4,
+	E_SRVLOHOLDOVERINSPECSTATE = 5,
+	E_SRVLOHOLDOVEROUTOFSPECSTATE = 6,
+	E_SRVLOFREERUNSTATE = 7,
+	E_SRVNUMBERLOSTATES = 8,
+	E_SRVLOSTATEINVALID = 9
+};
+
+extern int
+rsmu_cm_set_combomode(struct rsmu_cdev *rsmu, u8 dpll, u8 mode);
+extern int
+rsmu_cm_get_combomode(struct rsmu_cdev *rsmu, u8 dpll, u8 *mode);
+extern int
+rsmu_cm_get_dpll_state(struct rsmu_cdev *rsmu, u8 dpll, u8 *state);
+extern int
+rsmu_cm_get_dpll_ffo(struct rsmu_cdev *rsmu, u8 dpll, struct rsmu_get_ffo *ffo);
+extern int
+rsmu_sabre_set_combomode(struct rsmu_cdev *rsmu, u8 dpll, u8 mode);
+extern int
+rsmu_sabre_get_combomode(struct rsmu_cdev *rsmu, u8 dpll, u8 *mode);
+extern int
+rsmu_sabre_get_dpll_state(struct rsmu_cdev *rsmu, u8 dpll, u8 *state);
+extern int
+rsmu_sabre_get_dpll_ffo(struct rsmu_cdev *rsmu, u8 dpll,
+			struct rsmu_get_ffo *ffo);
+#endif
diff --git a/drivers/misc/rsmu_cm.c b/drivers/misc/rsmu_cm.c
new file mode 100644
index 0000000..26779e6
--- /dev/null
+++ b/drivers/misc/rsmu_cm.c
@@ -0,0 +1,214 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * This driver is developed for the IDT ClockMatrix(TM) of
+ * timing and synchronization devices.
+ *
+ * Copyright (C) 2019 Integrated Device Technology, Inc., a Renesas Company.
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/device.h>
+#include <linux/mfd/idt8a340_reg.h>
+#include <linux/mfd/rsmu.h>
+#include <uapi/linux/rsmu.h>
+
+#include "rsmu_cdev.h"
+
+int rsmu_cm_set_combomode(struct rsmu_cdev *rsmu, u8 dpll, u8 mode)
+{
+	u16 dpll_ctrl_n;
+	u8 cfg;
+	int err;
+
+	switch (dpll) {
+	case 0:
+		dpll_ctrl_n = DPLL_CTRL_0;
+		break;
+	case 1:
+		dpll_ctrl_n = DPLL_CTRL_1;
+		break;
+	case 2:
+		dpll_ctrl_n = DPLL_CTRL_2;
+		break;
+	case 3:
+		dpll_ctrl_n = DPLL_CTRL_3;
+		break;
+	case 4:
+		dpll_ctrl_n = DPLL_CTRL_4;
+		break;
+	case 5:
+		dpll_ctrl_n = DPLL_CTRL_5;
+		break;
+	case 6:
+		dpll_ctrl_n = DPLL_CTRL_6;
+		break;
+	case 7:
+		dpll_ctrl_n = DPLL_CTRL_7;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (mode >= E_COMBOMODE_MAX)
+		return -EINVAL;
+
+	err = rsmu_read(rsmu->mfd,
+			  dpll_ctrl_n + DPLL_CTRL_COMBO_MASTER_CFG,
+			  &cfg, sizeof(cfg));
+	if (err)
+		return err;
+
+	/* Only need to enable/disable COMBO_MODE_HOLD. */
+	if (mode)
+		cfg |= COMBO_MASTER_HOLD;
+	else
+		cfg &= ~COMBO_MASTER_HOLD;
+
+	return rsmu_write(rsmu->mfd,
+			    dpll_ctrl_n + DPLL_CTRL_COMBO_MASTER_CFG,
+			    &cfg, sizeof(cfg));
+}
+
+int rsmu_cm_get_combomode(struct rsmu_cdev *rsmu, u8 dpll, u8 *mode)
+{
+	u16 dpll_ctrl_n;
+	u8 cfg;
+	int err;
+
+	switch (dpll) {
+	case 0:
+		dpll_ctrl_n = DPLL_CTRL_0;
+		break;
+	case 1:
+		dpll_ctrl_n = DPLL_CTRL_1;
+		break;
+	case 2:
+		dpll_ctrl_n = DPLL_CTRL_2;
+		break;
+	case 3:
+		dpll_ctrl_n = DPLL_CTRL_3;
+		break;
+	case 4:
+		dpll_ctrl_n = DPLL_CTRL_4;
+		break;
+	case 5:
+		dpll_ctrl_n = DPLL_CTRL_5;
+		break;
+	case 6:
+		dpll_ctrl_n = DPLL_CTRL_6;
+		break;
+	case 7:
+		dpll_ctrl_n = DPLL_CTRL_7;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	err = rsmu_read(rsmu->mfd,
+			  dpll_ctrl_n + DPLL_CTRL_COMBO_MASTER_CFG,
+			  &cfg, sizeof(cfg));
+	if (err)
+		return err;
+
+	*mode = cfg & COMBO_MASTER_HOLD;
+
+	return 0;
+}
+
+int rsmu_cm_get_dpll_state(struct rsmu_cdev *rsmu, u8 dpll, u8 *state)
+{
+	u8 cfg;
+	int err;
+
+	/* 8 is sys dpll */
+	if (dpll > 8)
+		return -EINVAL;
+
+	err = rsmu_read(rsmu->mfd,
+			  STATUS + DPLL0_STATUS + dpll,
+			  &cfg, sizeof(cfg));
+	if (err)
+		return err;
+
+	switch (cfg & DPLL_STATE_MASK) {
+	case E_DPLL_STATE_FREERUN:
+		*state = E_SRVLOUNQUALIFIEDSTATE;
+		break;
+	case E_DPLL_STATE_LOCKACQ:
+	case E_DPLL_STATE_LOCKREQ:
+		*state = E_SRVLOLOCKACQSTATE;
+		break;
+	case E_DPLL_STATE_LOCKED:
+		*state = E_SRVLOTIMELOCKEDSTATE;
+		break;
+	case E_DPLL_STATE_HOLDOVER:
+		*state = E_SRVLOHOLDOVERINSPECSTATE;
+		break;
+	default:
+		*state = E_SRVLOSTATEINVALID;
+		break;
+	}
+
+	return 0;
+}
+
+int rsmu_cm_get_dpll_ffo(struct rsmu_cdev *rsmu, u8 dpll,
+			 struct rsmu_get_ffo *ffo)
+{
+	u8 buf[6] = {0};
+	s64 fcw = 0;
+	u16 dpll_filter_status;
+	int err;
+
+	switch (dpll) {
+	case 0:
+		dpll_filter_status = DPLL0_FILTER_STATUS;
+		break;
+	case 1:
+		dpll_filter_status = DPLL1_FILTER_STATUS;
+		break;
+	case 2:
+		dpll_filter_status = DPLL2_FILTER_STATUS;
+		break;
+	case 3:
+		dpll_filter_status = DPLL3_FILTER_STATUS;
+		break;
+	case 4:
+		dpll_filter_status = DPLL4_FILTER_STATUS;
+		break;
+	case 5:
+		dpll_filter_status = DPLL5_FILTER_STATUS;
+		break;
+	case 6:
+		dpll_filter_status = DPLL6_FILTER_STATUS;
+		break;
+	case 7:
+		dpll_filter_status = DPLL7_FILTER_STATUS;
+		break;
+	case 8:
+		dpll_filter_status = DPLLSYS_FILTER_STATUS;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	err = rsmu_read(rsmu->mfd, STATUS + dpll_filter_status, buf, 6);
+	if (err)
+		return err;
+
+	/* Convert to frequency control word */
+	fcw = buf[0];
+	fcw |= buf[1] << 8LL;
+	fcw |= buf[2] << 16LL;
+	fcw |= buf[3] << 24LL;
+	fcw |= buf[4] << 32LL;
+	fcw |= buf[5] << 40LL;
+	if (buf[5] & BIT(7))
+		/* Sign extend */
+		fcw |= GENMASK(63, 48);
+
+	/* FCW unit is 2 ^ -53 = 1.1102230246251565404236316680908e-16 */
+	ffo->ffo = fcw * 111;
+
+	return 0;
+}
diff --git a/drivers/misc/rsmu_sabre.c b/drivers/misc/rsmu_sabre.c
new file mode 100644
index 0000000..8b27d6e
--- /dev/null
+++ b/drivers/misc/rsmu_sabre.c
@@ -0,0 +1,153 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * This driver is developed for the IDT 82P33XXX series of
+ * timing and synchronization devices.
+ *
+ * Copyright (C) 2019 Integrated Device Technology, Inc., a Renesas Company.
+ */
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/device.h>
+#include <linux/mfd/idt82p33_reg.h>
+#include <linux/mfd/rsmu.h>
+#include <uapi/linux/rsmu.h>
+
+#include "rsmu_cdev.h"
+
+int rsmu_sabre_set_combomode(struct rsmu_cdev *rsmu, u8 dpll, u8 mode)
+{
+	u16 dpll_ctrl_n;
+	u8 cfg;
+	int err;
+
+	switch (dpll) {
+	case 0:
+		dpll_ctrl_n = DPLL1_OPERATING_MODE_CNFG;
+		break;
+	case 1:
+		dpll_ctrl_n = DPLL2_OPERATING_MODE_CNFG;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (mode >= E_COMBOMODE_MAX)
+		return -EINVAL;
+
+	err = rsmu_read(rsmu->mfd, dpll_ctrl_n, &cfg, sizeof(cfg));
+	if (err)
+		return err;
+
+	cfg &= ~(COMBO_MODE_MASK << COMBO_MODE_SHIFT);
+	cfg |= (mode << COMBO_MODE_SHIFT);
+
+	return rsmu_write(rsmu->mfd, dpll_ctrl_n, &cfg, sizeof(cfg));
+}
+
+int rsmu_sabre_get_combomode(struct rsmu_cdev *rsmu, u8 dpll, u8 *mode)
+{
+	u16 dpll_ctrl_n;
+	u8 cfg;
+	int err;
+
+	switch (dpll) {
+	case 0:
+		dpll_ctrl_n = DPLL1_OPERATING_MODE_CNFG;
+		break;
+	case 1:
+		dpll_ctrl_n = DPLL2_OPERATING_MODE_CNFG;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	err = rsmu_read(rsmu->mfd, dpll_ctrl_n, &cfg, sizeof(cfg));
+	if (err)
+		return err;
+
+	*mode = cfg >> COMBO_MODE_SHIFT;
+
+	return 0;
+}
+
+int rsmu_sabre_get_dpll_state(struct rsmu_cdev *rsmu, u8 dpll, u8 *state)
+{
+	u16 dpll_sts_n;
+	u8 cfg;
+	int err;
+
+	switch (dpll) {
+	case 0:
+		dpll_sts_n = DPLL1_OPERATING_STS;
+		break;
+	case 1:
+		dpll_sts_n = DPLL2_OPERATING_STS;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	err = rsmu_read(rsmu->mfd, dpll_sts_n, &cfg, sizeof(cfg));
+	if (err)
+		return err;
+
+	switch (cfg & OPERATING_STS_MASK) {
+	case DPLL_STATE_FREERUN:
+		*state = E_SRVLOUNQUALIFIEDSTATE;
+		break;
+	case DPLL_STATE_PRELOCKED2:
+	case DPLL_STATE_PRELOCKED:
+		*state = E_SRVLOLOCKACQSTATE;
+		break;
+	case DPLL_STATE_LOCKED:
+		*state = E_SRVLOTIMELOCKEDSTATE;
+		break;
+	case DPLL_STATE_HOLDOVER:
+		*state = E_SRVLOHOLDOVERINSPECSTATE;
+		break;
+	default:
+		*state = E_SRVLOSTATEINVALID;
+		break;
+	}
+
+	return 0;
+}
+
+int rsmu_sabre_get_dpll_ffo(struct rsmu_cdev *rsmu, u8 dpll,
+			    struct rsmu_get_ffo *ffo)
+{
+	u8 buf[5] = {0};
+	s64 fcw = 0;
+	u16 dpll_freq_n;
+	int err;
+
+	switch (dpll) {
+	case 0:
+		dpll_freq_n = DPLL1_HOLDOVER_FREQ_CNFG;
+		break;
+	case 1:
+		dpll_freq_n = DPLL2_HOLDOVER_FREQ_CNFG;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	err = rsmu_read(rsmu->mfd, dpll_freq_n, buf, 5);
+	if (err)
+		return err;
+
+	/* Convert to frequency control word */
+	fcw = buf[0];
+	fcw |= buf[1] << 8LL;
+	fcw |= buf[2] << 16LL;
+	fcw |= buf[3] << 24LL;
+	fcw |= buf[4] << 32LL;
+	if (buf[4] & BIT(7))
+		/* Sign extend */
+		fcw |= GENMASK(63, 40);
+
+	/* FCW unit is 77760 / ( 1638400 * 2^48) = 1.68615121864946 * 10^-16 */
+	ffo->ffo = div_s64(fcw * 168615, 1000);
+
+	return 0;
+}
diff --git a/include/uapi/linux/rsmu.h b/include/uapi/linux/rsmu.h
new file mode 100644
index 0000000..895e383
--- /dev/null
+++ b/include/uapi/linux/rsmu.h
@@ -0,0 +1,61 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Driver for the IDT ClockMatrix(TM) and 82p33xxx families of
+ * timing and synchronization devices.
+ *
+ * Copyright (C) 2019 Integrated Device Technology, Inc., a Renesas Company.
+ */
+
+#ifndef __UAPI_LINUX_RSMU_CDEV_H
+#define __UAPI_LINUX_RSMU_CDEV_H
+
+/* Set dpll combomode */
+struct rsmu_combomode {
+	__u8 dpll;
+	__u8 mode;
+};
+
+/* Get dpll state */
+struct rsmu_get_state {
+	__u8 dpll;
+	__u8 state;
+};
+
+/* Get dpll ffo */
+struct rsmu_get_ffo {
+	__u8 dpll;
+	__s64 ffo; /* in ppqt */
+};
+
+/*
+ * RSMU IOCTL List
+ */
+#define RSMU_MAGIC '?'
+
+/**
+ * @Description
+ * ioctl to set SMU combo mode.
+ *
+ * @Parameters
+ * pointer to struct rsmu_combomode that contains dpll combomode setting
+ */
+#define RSMU_SET_COMBOMODE  _IOW(RSMU_MAGIC, 1, struct rsmu_combomode *)
+
+/**
+ * @Description
+ * ioctl to get SMU dpll state.
+ *
+ * @Parameters
+ * pointer to struct rsmu_get_state that contains dpll state
+ */
+#define RSMU_GET_STATE  _IOW(RSMU_MAGIC, 2, struct rsmu_get_state *)
+
+/**
+ * @Description
+ * ioctl to get SMU dpll ffo.
+ *
+ * @Parameters
+ * pointer to struct rsmu_get_ffo that contains dpll fcw and granularity
+ */
+#define RSMU_GET_FFO  _IOW(RSMU_MAGIC, 3, struct rsmu_get_ffo *)
+#endif /* __UAPI_LINUX_RSMU_CDEV_H */
-- 
2.7.4