diff --git a/Documentation/hwmon/aspeed-pwm-tacho b/Documentation/hwmon/aspeed-pwm-tacho
new file mode 100644
index 000000000000..7cfb34977460
--- /dev/null
+++ b/Documentation/hwmon/aspeed-pwm-tacho
@@ -0,0 +1,22 @@
+Kernel driver aspeed-pwm-tacho
+==============================
+
+Supported chips:
+	ASPEED AST2400/2500
+
+Authors:
+	<jaghu@google.com>
+
+Description:
+------------
+This driver implements support for ASPEED AST2400/2500 PWM and Fan Tacho
+controller. The PWM controller supports upto 8 PWM outputs. The Fan tacho
+controller supports up to 16 tachometer inputs.
+
+The driver provides the following sensor accesses in sysfs:
+
+fanX_input	ro	provide current fan rotation value in RPM as reported
+			by the fan to the device.
+
+pwmX		rw	get or set PWM fan control value. This is an integer
+			value between 0(off) and 255(full speed).
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 45cef3d2c75c..757b5b0705bf 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -341,6 +341,15 @@ config SENSORS_ASB100
 	  This driver can also be built as a module.  If so, the module
 	  will be called asb100.

+config SENSORS_ASPEED
+	tristate "ASPEED AST2400/AST2500 PWM and Fan tach driver"
+	help
+	  This driver provides support for ASPEED AST2400/AST2500 PWM
+	  and Fan Tacho controllers.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called aspeed_pwm_tacho.
+
 config SENSORS_ATXP1
 	tristate "Attansic ATXP1 VID controller"
 	depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index aecf4ba17460..83025cc9bb45 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -46,6 +46,7 @@ obj-$(CONFIG_SENSORS_ADT7475)	+= adt7475.o
 obj-$(CONFIG_SENSORS_APPLESMC)	+= applesmc.o
 obj-$(CONFIG_SENSORS_ARM_SCPI)	+= scpi-hwmon.o
 obj-$(CONFIG_SENSORS_ASC7621)	+= asc7621.o
+obj-$(CONFIG_SENSORS_ASPEED)	+= aspeed-pwm-tacho.o
 obj-$(CONFIG_SENSORS_ATXP1)	+= atxp1.o
 obj-$(CONFIG_SENSORS_CORETEMP)	+= coretemp.o
 obj-$(CONFIG_SENSORS_DA9052_ADC)+= da9052-hwmon.o
diff --git a/drivers/hwmon/aspeed-pwm-tacho.c b/drivers/hwmon/aspeed-pwm-tacho.c
new file mode 100644
index 000000000000..29010ad94208
--- /dev/null
+++ b/drivers/hwmon/aspeed-pwm-tacho.c
@@ -0,0 +1,846 @@
+/*
+ * Copyright (c) 2016 Google, Inc
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 or later as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/clk.h>
+#include <linux/gpio/consumer.h>
+#include <linux/delay.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/sysfs.h>
+#include <linux/regmap.h>
+
+/* ASPEED PWM & FAN Tach Register Definition */
+#define ASPEED_PTCR_CTRL		0x00
+#define ASPEED_PTCR_CLK_CTRL		0x04
+#define ASPEED_PTCR_DUTY0_CTRL		0x08
+#define ASPEED_PTCR_DUTY1_CTRL		0x0c
+#define ASPEED_PTCR_TYPEM_CTRL		0x10
+#define ASPEED_PTCR_TYPEM_CTRL1		0x14
+#define ASPEED_PTCR_TYPEN_CTRL		0x18
+#define ASPEED_PTCR_TYPEN_CTRL1		0x1c
+#define ASPEED_PTCR_TACH_SOURCE		0x20
+#define ASPEED_PTCR_TRIGGER		0x28
+#define ASPEED_PTCR_RESULT		0x2c
+#define ASPEED_PTCR_INTR_CTRL		0x30
+#define ASPEED_PTCR_INTR_STS		0x34
+#define ASPEED_PTCR_TYPEM_LIMIT		0x38
+#define ASPEED_PTCR_TYPEN_LIMIT		0x3C
+#define ASPEED_PTCR_CTRL_EXT		0x40
+#define ASPEED_PTCR_CLK_CTRL_EXT	0x44
+#define ASPEED_PTCR_DUTY2_CTRL		0x48
+#define ASPEED_PTCR_DUTY3_CTRL		0x4c
+#define ASPEED_PTCR_TYPEO_CTRL		0x50
+#define ASPEED_PTCR_TYPEO_CTRL1		0x54
+#define ASPEED_PTCR_TACH_SOURCE_EXT	0x60
+#define ASPEED_PTCR_TYPEO_LIMIT		0x78
+
+/* ASPEED_PTCR_CTRL : 0x00 - General Control Register */
+#define ASPEED_PTCR_CTRL_SET_PWMD_TYPE_PART1	15
+#define ASPEED_PTCR_CTRL_SET_PWMD_TYPE_PART2	6
+#define ASPEED_PTCR_CTRL_SET_PWMD_TYPE_MASK	(BIT(7) | BIT(15))
+
+#define ASPEED_PTCR_CTRL_SET_PWMC_TYPE_PART1	14
+#define ASPEED_PTCR_CTRL_SET_PWMC_TYPE_PART2	5
+#define ASPEED_PTCR_CTRL_SET_PWMC_TYPE_MASK	(BIT(6) | BIT(14))
+
+#define ASPEED_PTCR_CTRL_SET_PWMB_TYPE_PART1	13
+#define ASPEED_PTCR_CTRL_SET_PWMB_TYPE_PART2	4
+#define ASPEED_PTCR_CTRL_SET_PWMB_TYPE_MASK	(BIT(5) | BIT(13))
+
+#define ASPEED_PTCR_CTRL_SET_PWMA_TYPE_PART1	12
+#define ASPEED_PTCR_CTRL_SET_PWMA_TYPE_PART2	3
+#define ASPEED_PTCR_CTRL_SET_PWMA_TYPE_MASK	(BIT(4) | BIT(12))
+
+#define	ASPEED_PTCR_CTRL_FAN_NUM_EN(x)	BIT(16 + (x))
+
+#define	ASPEED_PTCR_CTRL_PWMD_EN	BIT(11)
+#define	ASPEED_PTCR_CTRL_PWMC_EN	BIT(10)
+#define	ASPEED_PTCR_CTRL_PWMB_EN	BIT(9)
+#define	ASPEED_PTCR_CTRL_PWMA_EN	BIT(8)
+
+#define	ASPEED_PTCR_CTRL_CLK_SRC	BIT(1)
+#define	ASPEED_PTCR_CTRL_CLK_EN		BIT(0)
+
+/* ASPEED_PTCR_CLK_CTRL : 0x04 - Clock Control Register */
+/* TYPE N */
+#define ASPEED_PTCR_CLK_CTRL_TYPEN_MASK		GENMASK(31, 16)
+#define ASPEED_PTCR_CLK_CTRL_TYPEN_UNIT		24
+#define ASPEED_PTCR_CLK_CTRL_TYPEN_H		20
+#define ASPEED_PTCR_CLK_CTRL_TYPEN_L		16
+/* TYPE M */
+#define ASPEED_PTCR_CLK_CTRL_TYPEM_MASK         GENMASK(15, 0)
+#define ASPEED_PTCR_CLK_CTRL_TYPEM_UNIT		8
+#define ASPEED_PTCR_CLK_CTRL_TYPEM_H		4
+#define ASPEED_PTCR_CLK_CTRL_TYPEM_L		0
+
+/*
+ * ASPEED_PTCR_DUTY_CTRL/1/2/3 : 0x08/0x0C/0x48/0x4C - PWM-FAN duty control
+ * 0/1/2/3 register
+ */
+#define DUTY_CTRL_PWM2_FALL_POINT	24
+#define DUTY_CTRL_PWM2_RISE_POINT	16
+#define DUTY_CTRL_PWM2_RISE_FALL_MASK	GENMASK(31, 16)
+#define DUTY_CTRL_PWM1_FALL_POINT	8
+#define DUTY_CTRL_PWM1_RISE_POINT	0
+#define DUTY_CTRL_PWM1_RISE_FALL_MASK   GENMASK(15, 0)
+
+/* ASPEED_PTCR_TYPEM_CTRL : 0x10/0x18/0x50 - Type M/N/O Ctrl 0 Register */
+#define TYPE_CTRL_FAN_MASK		(GENMASK(5, 1) | GENMASK(31, 16))
+#define TYPE_CTRL_FAN1_MASK		GENMASK(31, 0)
+#define TYPE_CTRL_FAN_PERIOD		16
+#define TYPE_CTRL_FAN_MODE		4
+#define TYPE_CTRL_FAN_DIVISION		1
+#define TYPE_CTRL_FAN_TYPE_EN		1
+
+/* ASPEED_PTCR_TACH_SOURCE : 0x20/0x60 - Tach Source Register */
+/* bit [0,1] at 0x20, bit [2] at 0x60 */
+#define TACH_PWM_SOURCE_BIT01(x)	((x) * 2)
+#define TACH_PWM_SOURCE_BIT2(x)		((x) * 2)
+#define TACH_PWM_SOURCE_MASK_BIT01(x)	(0x3 << ((x) * 2))
+#define TACH_PWM_SOURCE_MASK_BIT2(x)	BIT((x) * 2)
+
+/* ASPEED_PTCR_RESULT : 0x2c - Result Register */
+#define RESULT_STATUS_MASK		BIT(31)
+#define RESULT_VALUE_MASK		0xfffff
+
+/* ASPEED_PTCR_CTRL_EXT : 0x40 - General Control Extension #1 Register */
+#define ASPEED_PTCR_CTRL_SET_PWMH_TYPE_PART1	15
+#define ASPEED_PTCR_CTRL_SET_PWMH_TYPE_PART2	6
+#define ASPEED_PTCR_CTRL_SET_PWMH_TYPE_MASK	(BIT(7) | BIT(15))
+
+#define ASPEED_PTCR_CTRL_SET_PWMG_TYPE_PART1	14
+#define ASPEED_PTCR_CTRL_SET_PWMG_TYPE_PART2	5
+#define ASPEED_PTCR_CTRL_SET_PWMG_TYPE_MASK	(BIT(6) | BIT(14))
+
+#define ASPEED_PTCR_CTRL_SET_PWMF_TYPE_PART1	13
+#define ASPEED_PTCR_CTRL_SET_PWMF_TYPE_PART2	4
+#define ASPEED_PTCR_CTRL_SET_PWMF_TYPE_MASK	(BIT(5) | BIT(13))
+
+#define ASPEED_PTCR_CTRL_SET_PWME_TYPE_PART1	12
+#define ASPEED_PTCR_CTRL_SET_PWME_TYPE_PART2	3
+#define ASPEED_PTCR_CTRL_SET_PWME_TYPE_MASK	(BIT(4) | BIT(12))
+
+#define	ASPEED_PTCR_CTRL_PWMH_EN	BIT(11)
+#define	ASPEED_PTCR_CTRL_PWMG_EN	BIT(10)
+#define	ASPEED_PTCR_CTRL_PWMF_EN	BIT(9)
+#define	ASPEED_PTCR_CTRL_PWME_EN	BIT(8)
+
+/* ASPEED_PTCR_CLK_EXT_CTRL : 0x44 - Clock Control Extension #1 Register */
+/* TYPE O */
+#define ASPEED_PTCR_CLK_CTRL_TYPEO_MASK         GENMASK(15, 0)
+#define ASPEED_PTCR_CLK_CTRL_TYPEO_UNIT		8
+#define ASPEED_PTCR_CLK_CTRL_TYPEO_H		4
+#define ASPEED_PTCR_CLK_CTRL_TYPEO_L		0
+
+#define PWM_MAX 255
+
+#define M_PWM_DIV_H 0x00
+#define M_PWM_DIV_L 0x05
+#define M_PWM_PERIOD 0x5F
+#define M_TACH_CLK_DIV 0x00
+#define M_TACH_MODE 0x00
+#define M_TACH_UNIT 0x1000
+#define INIT_FAN_CTRL 0xFF
+
+void __iomem *regs;
+
+struct aspeed_pwm_tacho_data {
+	struct regmap *regmap;
+	unsigned long clk_freq;
+	bool pwm_present[8];
+	bool fan_tach_present[16];
+	u8 type_pwm_clock_unit[3];
+	u8 type_pwm_clock_division_h[3];
+	u8 type_pwm_clock_division_l[3];
+	u8 type_fan_tach_clock_division[3];
+	u16 type_fan_tach_unit[3];
+	u8 pwm_port_type[8];
+	u8 pwm_port_fan_ctrl[8];
+	u8 fan_tach_ch_source[16];
+	const struct attribute_group *groups[3];
+};
+
+enum type { TYPEM, TYPEN, TYPEO };
+
+struct type_params {
+	u32 l_value;
+	u32 h_value;
+	u32 unit_value;
+	u32 clk_ctrl_mask;
+	u32 clk_ctrl_reg;
+	u32 ctrl_reg;
+	u32 ctrl_reg1;
+};
+
+static const struct type_params type_params[] = {
+	[TYPEM] = {
+		.l_value = ASPEED_PTCR_CLK_CTRL_TYPEM_L,
+		.h_value = ASPEED_PTCR_CLK_CTRL_TYPEM_H,
+		.unit_value = ASPEED_PTCR_CLK_CTRL_TYPEM_UNIT,
+		.clk_ctrl_mask = ASPEED_PTCR_CLK_CTRL_TYPEM_MASK,
+		.clk_ctrl_reg = ASPEED_PTCR_CLK_CTRL,
+		.ctrl_reg = ASPEED_PTCR_TYPEM_CTRL,
+		.ctrl_reg1 = ASPEED_PTCR_TYPEM_CTRL1,
+	},
+	[TYPEN] = {
+		.l_value = ASPEED_PTCR_CLK_CTRL_TYPEN_L,
+		.h_value = ASPEED_PTCR_CLK_CTRL_TYPEN_H,
+		.unit_value = ASPEED_PTCR_CLK_CTRL_TYPEN_UNIT,
+		.clk_ctrl_mask = ASPEED_PTCR_CLK_CTRL_TYPEN_MASK,
+		.clk_ctrl_reg = ASPEED_PTCR_CLK_CTRL,
+		.ctrl_reg = ASPEED_PTCR_TYPEN_CTRL,
+		.ctrl_reg1 = ASPEED_PTCR_TYPEN_CTRL1,
+	},
+	[TYPEO] = {
+		.l_value = ASPEED_PTCR_CLK_CTRL_TYPEO_L,
+		.h_value = ASPEED_PTCR_CLK_CTRL_TYPEO_H,
+		.unit_value = ASPEED_PTCR_CLK_CTRL_TYPEO_UNIT,
+		.clk_ctrl_mask = ASPEED_PTCR_CLK_CTRL_TYPEO_MASK,
+		.clk_ctrl_reg = ASPEED_PTCR_CLK_CTRL_EXT,
+		.ctrl_reg = ASPEED_PTCR_TYPEO_CTRL,
+		.ctrl_reg1 = ASPEED_PTCR_TYPEO_CTRL1,
+	}
+};
+
+enum pwm_port { PWMA, PWMB, PWMC, PWMD, PWME, PWMF, PWMG, PWMH };
+
+struct pwm_port_params {
+	u32 pwm_en;
+	u32 ctrl_reg;
+	u32 type_part1;
+	u32 type_part2;
+	u32 type_mask;
+	u32 duty_ctrl_rise_point;
+	u32 duty_ctrl_fall_point;
+	u32 duty_ctrl_reg;
+	u32 duty_ctrl_rise_fall_mask;
+};
+
+static const struct pwm_port_params pwm_port_params[] = {
+	[PWMA] = {
+		.pwm_en = ASPEED_PTCR_CTRL_PWMA_EN,
+		.ctrl_reg = ASPEED_PTCR_CTRL,
+		.type_part1 = ASPEED_PTCR_CTRL_SET_PWMA_TYPE_PART1,
+		.type_part2 = ASPEED_PTCR_CTRL_SET_PWMA_TYPE_PART2,
+		.type_mask = ASPEED_PTCR_CTRL_SET_PWMA_TYPE_MASK,
+		.duty_ctrl_rise_point = DUTY_CTRL_PWM1_RISE_POINT,
+		.duty_ctrl_fall_point = DUTY_CTRL_PWM1_FALL_POINT,
+		.duty_ctrl_reg = ASPEED_PTCR_DUTY0_CTRL,
+		.duty_ctrl_rise_fall_mask = DUTY_CTRL_PWM1_RISE_FALL_MASK,
+	},
+	[PWMB] = {
+		.pwm_en = ASPEED_PTCR_CTRL_PWMB_EN,
+		.ctrl_reg = ASPEED_PTCR_CTRL,
+		.type_part1 = ASPEED_PTCR_CTRL_SET_PWMB_TYPE_PART1,
+		.type_part2 = ASPEED_PTCR_CTRL_SET_PWMB_TYPE_PART2,
+		.type_mask = ASPEED_PTCR_CTRL_SET_PWMB_TYPE_MASK,
+		.duty_ctrl_rise_point = DUTY_CTRL_PWM2_RISE_POINT,
+		.duty_ctrl_fall_point = DUTY_CTRL_PWM2_FALL_POINT,
+		.duty_ctrl_reg = ASPEED_PTCR_DUTY0_CTRL,
+		.duty_ctrl_rise_fall_mask = DUTY_CTRL_PWM2_RISE_FALL_MASK,
+	},
+	[PWMC] = {
+		.pwm_en = ASPEED_PTCR_CTRL_PWMC_EN,
+		.ctrl_reg = ASPEED_PTCR_CTRL,
+		.type_part1 = ASPEED_PTCR_CTRL_SET_PWMC_TYPE_PART1,
+		.type_part2 = ASPEED_PTCR_CTRL_SET_PWMC_TYPE_PART2,
+		.type_mask = ASPEED_PTCR_CTRL_SET_PWMC_TYPE_MASK,
+		.duty_ctrl_rise_point = DUTY_CTRL_PWM1_RISE_POINT,
+		.duty_ctrl_fall_point = DUTY_CTRL_PWM1_FALL_POINT,
+		.duty_ctrl_reg = ASPEED_PTCR_DUTY1_CTRL,
+		.duty_ctrl_rise_fall_mask = DUTY_CTRL_PWM1_RISE_FALL_MASK,
+	},
+	[PWMD] = {
+		.pwm_en = ASPEED_PTCR_CTRL_PWMD_EN,
+		.ctrl_reg = ASPEED_PTCR_CTRL,
+		.type_part1 = ASPEED_PTCR_CTRL_SET_PWMD_TYPE_PART1,
+		.type_part2 = ASPEED_PTCR_CTRL_SET_PWMD_TYPE_PART2,
+		.type_mask = ASPEED_PTCR_CTRL_SET_PWMD_TYPE_MASK,
+		.duty_ctrl_rise_point = DUTY_CTRL_PWM2_RISE_POINT,
+		.duty_ctrl_fall_point = DUTY_CTRL_PWM2_FALL_POINT,
+		.duty_ctrl_reg = ASPEED_PTCR_DUTY1_CTRL,
+		.duty_ctrl_rise_fall_mask = DUTY_CTRL_PWM2_RISE_FALL_MASK,
+	},
+	[PWME] = {
+		.pwm_en = ASPEED_PTCR_CTRL_PWME_EN,
+		.ctrl_reg = ASPEED_PTCR_CTRL_EXT,
+		.type_part1 = ASPEED_PTCR_CTRL_SET_PWME_TYPE_PART1,
+		.type_part2 = ASPEED_PTCR_CTRL_SET_PWME_TYPE_PART2,
+		.type_mask = ASPEED_PTCR_CTRL_SET_PWME_TYPE_MASK,
+		.duty_ctrl_rise_point = DUTY_CTRL_PWM1_RISE_POINT,
+		.duty_ctrl_fall_point = DUTY_CTRL_PWM1_FALL_POINT,
+		.duty_ctrl_reg = ASPEED_PTCR_DUTY2_CTRL,
+		.duty_ctrl_rise_fall_mask = DUTY_CTRL_PWM1_RISE_FALL_MASK,
+	},
+	[PWMF] = {
+		.pwm_en = ASPEED_PTCR_CTRL_PWMF_EN,
+		.ctrl_reg = ASPEED_PTCR_CTRL_EXT,
+		.type_part1 = ASPEED_PTCR_CTRL_SET_PWMF_TYPE_PART1,
+		.type_part2 = ASPEED_PTCR_CTRL_SET_PWMF_TYPE_PART2,
+		.type_mask = ASPEED_PTCR_CTRL_SET_PWMF_TYPE_MASK,
+		.duty_ctrl_rise_point = DUTY_CTRL_PWM2_RISE_POINT,
+		.duty_ctrl_fall_point = DUTY_CTRL_PWM2_FALL_POINT,
+		.duty_ctrl_reg = ASPEED_PTCR_DUTY2_CTRL,
+		.duty_ctrl_rise_fall_mask = DUTY_CTRL_PWM2_RISE_FALL_MASK,
+	},
+	[PWMG] = {
+		.pwm_en = ASPEED_PTCR_CTRL_PWMG_EN,
+		.ctrl_reg = ASPEED_PTCR_CTRL_EXT,
+		.type_part1 = ASPEED_PTCR_CTRL_SET_PWMG_TYPE_PART1,
+		.type_part2 = ASPEED_PTCR_CTRL_SET_PWMG_TYPE_PART2,
+		.type_mask = ASPEED_PTCR_CTRL_SET_PWMG_TYPE_MASK,
+		.duty_ctrl_rise_point = DUTY_CTRL_PWM1_RISE_POINT,
+		.duty_ctrl_fall_point = DUTY_CTRL_PWM1_FALL_POINT,
+		.duty_ctrl_reg = ASPEED_PTCR_DUTY3_CTRL,
+		.duty_ctrl_rise_fall_mask = DUTY_CTRL_PWM1_RISE_FALL_MASK,
+	},
+	[PWMH] = {
+		.pwm_en = ASPEED_PTCR_CTRL_PWMH_EN,
+		.ctrl_reg = ASPEED_PTCR_CTRL_EXT,
+		.type_part1 = ASPEED_PTCR_CTRL_SET_PWMH_TYPE_PART1,
+		.type_part2 = ASPEED_PTCR_CTRL_SET_PWMH_TYPE_PART2,
+		.type_mask = ASPEED_PTCR_CTRL_SET_PWMH_TYPE_MASK,
+		.duty_ctrl_rise_point = DUTY_CTRL_PWM2_RISE_POINT,
+		.duty_ctrl_fall_point = DUTY_CTRL_PWM2_FALL_POINT,
+		.duty_ctrl_reg = ASPEED_PTCR_DUTY3_CTRL,
+		.duty_ctrl_rise_fall_mask = DUTY_CTRL_PWM2_RISE_FALL_MASK,
+	}
+};
+
+static int regmap_aspeed_pwm_tacho_reg_write(void *context, unsigned int reg,
+					     unsigned int val)
+{
+	void __iomem *regs = context;
+
+	writel(val, regs + reg);
+	return 0;
+}
+
+static int regmap_aspeed_pwm_tacho_reg_read(void *context, unsigned int reg,
+					    unsigned int *val)
+{
+	void __iomem *regs = context;
+
+	*val = readl(regs + reg);
+	return 0;
+}
+
+static const struct regmap_config aspeed_pwm_tacho_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = ASPEED_PTCR_TYPEO_LIMIT,
+	.reg_write = regmap_aspeed_pwm_tacho_reg_write,
+	.reg_read = regmap_aspeed_pwm_tacho_reg_read,
+	.fast_io = true,
+};
+
+static void aspeed_set_clock_enable(struct regmap *regmap, bool val)
+{
+	regmap_update_bits(regmap, ASPEED_PTCR_CTRL,
+			   ASPEED_PTCR_CTRL_CLK_EN,
+			   val ? ASPEED_PTCR_CTRL_CLK_EN : 0);
+}
+
+static void aspeed_set_clock_source(struct regmap *regmap, int val)
+{
+	regmap_update_bits(regmap, ASPEED_PTCR_CTRL,
+			   ASPEED_PTCR_CTRL_CLK_SRC,
+			   val ? ASPEED_PTCR_CTRL_CLK_SRC : 0);
+}
+
+static void aspeed_set_pwm_clock_values(struct regmap *regmap, u8 type,
+					u8 div_high, u8 div_low, u8 unit)
+{
+	u32 reg_value = ((div_high << type_params[type].h_value) |
+			 (div_low << type_params[type].l_value) |
+			 (unit << type_params[type].unit_value));
+
+	regmap_update_bits(regmap, type_params[type].clk_ctrl_reg,
+			   type_params[type].clk_ctrl_mask, reg_value);
+}
+
+static void aspeed_set_pwm_port_enable(struct regmap *regmap, u8 pwm_port,
+				       bool enable)
+{
+	regmap_update_bits(regmap, pwm_port_params[pwm_port].ctrl_reg,
+			   pwm_port_params[pwm_port].pwm_en,
+			   enable ? pwm_port_params[pwm_port].pwm_en : 0);
+}
+
+static void aspeed_set_pwm_port_type(struct regmap *regmap,
+				     u8 pwm_port, u8 type)
+{
+	u32 reg_value = (type & 0x1) << pwm_port_params[pwm_port].type_part1;
+
+	reg_value |= (type & 0x2) << pwm_port_params[pwm_port].type_part2;
+
+	regmap_update_bits(regmap, pwm_port_params[pwm_port].ctrl_reg,
+			   pwm_port_params[pwm_port].type_mask, reg_value);
+}
+
+static void aspeed_set_pwm_port_duty_rising_falling(struct regmap *regmap,
+						    u8 pwm_port, u8 rising,
+						    u8 falling)
+{
+	u32 reg_value = (rising <<
+			 pwm_port_params[pwm_port].duty_ctrl_rise_point);
+	reg_value |= (falling <<
+		      pwm_port_params[pwm_port].duty_ctrl_fall_point);
+
+	regmap_update_bits(regmap, pwm_port_params[pwm_port].duty_ctrl_reg,
+			   pwm_port_params[pwm_port].duty_ctrl_rise_fall_mask,
+			   reg_value);
+}
+
+static void aspeed_set_tacho_type_enable(struct regmap *regmap, u8 type,
+					 bool enable)
+{
+	regmap_update_bits(regmap, type_params[type].ctrl_reg,
+			   TYPE_CTRL_FAN_TYPE_EN,
+			   enable ? TYPE_CTRL_FAN_TYPE_EN : 0);
+}
+
+static void aspeed_set_tacho_type_values(struct regmap *regmap, u8 type,
+					 u8 mode, u16 unit, u8 division)
+{
+	u32 reg_value = ((mode << TYPE_CTRL_FAN_MODE) |
+			 (unit << TYPE_CTRL_FAN_PERIOD) |
+			 (division << TYPE_CTRL_FAN_DIVISION));
+
+	regmap_update_bits(regmap, type_params[type].ctrl_reg,
+			   TYPE_CTRL_FAN_MASK, reg_value);
+	regmap_update_bits(regmap, type_params[type].ctrl_reg1,
+			   TYPE_CTRL_FAN1_MASK, unit << 16);
+}
+
+static void aspeed_set_fan_tach_ch_enable(struct regmap *regmap, u8 fan_tach_ch,
+					  bool enable)
+{
+	regmap_update_bits(regmap, ASPEED_PTCR_CTRL,
+			   ASPEED_PTCR_CTRL_FAN_NUM_EN(fan_tach_ch),
+			   enable ?
+			   ASPEED_PTCR_CTRL_FAN_NUM_EN(fan_tach_ch) : 0);
+}
+
+static void aspeed_set_fan_tach_ch_source(struct regmap *regmap, u8 fan_tach_ch,
+					  u8 fan_tach_ch_source)
+{
+	u32 reg_value1 = ((fan_tach_ch_source & 0x3) <<
+			  TACH_PWM_SOURCE_BIT01(fan_tach_ch));
+	u32 reg_value2 = (((fan_tach_ch_source & 0x4) >> 2) <<
+			  TACH_PWM_SOURCE_BIT2(fan_tach_ch));
+
+	regmap_update_bits(regmap, ASPEED_PTCR_TACH_SOURCE,
+			   TACH_PWM_SOURCE_MASK_BIT01(fan_tach_ch),
+			   reg_value1);
+
+	regmap_update_bits(regmap, ASPEED_PTCR_TACH_SOURCE_EXT,
+			   TACH_PWM_SOURCE_MASK_BIT2(fan_tach_ch),
+			   reg_value2);
+}
+
+static void aspeed_set_pwm_port_fan_ctrl(struct aspeed_pwm_tacho_data *priv,
+					 u8 index, u8 fan_ctrl)
+{
+	u16 period, dc_time_on;
+
+	period = priv->type_pwm_clock_unit[priv->pwm_port_type[index]];
+	period += 1;
+	dc_time_on = (fan_ctrl * period) / PWM_MAX;
+
+	if (dc_time_on == 0) {
+		aspeed_set_pwm_port_enable(priv->regmap, index, false);
+	} else {
+		if (dc_time_on == period)
+			dc_time_on = 0;
+
+		aspeed_set_pwm_port_duty_rising_falling(priv->regmap, index, 0,
+							dc_time_on);
+		aspeed_set_pwm_port_enable(priv->regmap, index, true);
+	}
+}
+
+static u32 aspeed_get_fan_tach_ch_measure_period(struct aspeed_pwm_tacho_data
+						 *priv, u8 type)
+{
+	u32 clk;
+	u16 tacho_unit;
+	u8 clk_unit, div_h, div_l, tacho_div;
+
+	clk = priv->clk_freq;
+	clk_unit = priv->type_pwm_clock_unit[type];
+	div_h = priv->type_pwm_clock_division_h[type];
+	div_h = 0x1 << div_h;
+	div_l = priv->type_pwm_clock_division_l[type];
+	if (div_l == 0)
+		div_l = 1;
+	else
+		div_l = div_l * 2;
+
+	tacho_unit = priv->type_fan_tach_unit[type];
+	tacho_div = priv->type_fan_tach_clock_division[type];
+
+	tacho_div = 0x4 << (tacho_div * 2);
+	return clk / (clk_unit * div_h * div_l * tacho_div * tacho_unit);
+}
+
+static u32 aspeed_get_fan_tach_ch_rpm(struct aspeed_pwm_tacho_data *priv,
+				      u8 fan_tach_ch)
+{
+	u32 raw_data, tach_div, clk_source, timeout = 0, sec, val;
+	u8 fan_tach_ch_source, type;
+
+	regmap_write(priv->regmap, ASPEED_PTCR_TRIGGER, 0);
+	regmap_write(priv->regmap, ASPEED_PTCR_TRIGGER, 0x1 << fan_tach_ch);
+
+	fan_tach_ch_source = priv->fan_tach_ch_source[fan_tach_ch];
+	type = priv->pwm_port_type[fan_tach_ch_source];
+
+	sec = (1000 / aspeed_get_fan_tach_ch_measure_period(priv, type));
+
+	msleep(sec);
+
+	while (!(regmap_read(priv->regmap, ASPEED_PTCR_RESULT, &val))
+			& !(val & RESULT_STATUS_MASK)) {
+		timeout++;
+		if (timeout > 1)
+			return 0;
+		msleep(sec);
+	}
+
+	raw_data = val & RESULT_VALUE_MASK;
+	tach_div = priv->type_fan_tach_clock_division[type];
+	tach_div = 0x4 << (tach_div * 2);
+	clk_source = priv->clk_freq;
+
+	if (raw_data == 0)
+		return 0;
+
+	return (clk_source * 60) / (2 * raw_data * tach_div);
+}
+
+static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
+		       const char *buf, size_t count)
+{
+	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
+	int index = sensor_attr->index;
+	int ret;
+	struct aspeed_pwm_tacho_data *priv = dev_get_drvdata(dev);
+	long fan_ctrl;
+
+	ret = kstrtol(buf, 10, &fan_ctrl);
+	if (ret != 0)
+		return ret;
+
+	if (fan_ctrl < 0 || fan_ctrl > PWM_MAX)
+		return -EINVAL;
+
+	if (priv->pwm_port_fan_ctrl[index] == fan_ctrl)
+		return count;
+
+	priv->pwm_port_fan_ctrl[index] = fan_ctrl;
+	aspeed_set_pwm_port_fan_ctrl(priv, index, fan_ctrl);
+
+	return count;
+}
+
+static ssize_t show_pwm(struct device *dev, struct device_attribute *attr,
+			char *buf)
+{
+	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
+	int index = sensor_attr->index;
+	struct aspeed_pwm_tacho_data *priv = dev_get_drvdata(dev);
+
+	return sprintf(buf, "%u\n", priv->pwm_port_fan_ctrl[index]);
+}
+
+static ssize_t show_rpm(struct device *dev, struct device_attribute *attr,
+			char *buf)
+{
+	struct sensor_device_attribute *sensor_attr = to_sensor_dev_attr(attr);
+	int index = sensor_attr->index;
+	u32 rpm;
+	struct aspeed_pwm_tacho_data *priv = dev_get_drvdata(dev);
+
+	rpm = aspeed_get_fan_tach_ch_rpm(priv, index);
+
+	return sprintf(buf, "%u\n", rpm);
+}
+
+static umode_t pwm_is_visible(struct kobject *kobj,
+			      struct attribute *a, int index)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct aspeed_pwm_tacho_data *priv = dev_get_drvdata(dev);
+
+	if (!priv->pwm_present[index])
+		return 0;
+	return a->mode;
+}
+
+static umode_t fan_dev_is_visible(struct kobject *kobj,
+				  struct attribute *a, int index)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct aspeed_pwm_tacho_data *priv = dev_get_drvdata(dev);
+
+	if (!priv->fan_tach_present[index])
+		return 0;
+	return a->mode;
+}
+
+static SENSOR_DEVICE_ATTR(pwm0, 0644,
+			show_pwm, set_pwm, 0);
+static SENSOR_DEVICE_ATTR(pwm1, 0644,
+			show_pwm, set_pwm, 1);
+static SENSOR_DEVICE_ATTR(pwm2, 0644,
+			show_pwm, set_pwm, 2);
+static SENSOR_DEVICE_ATTR(pwm3, 0644,
+			show_pwm, set_pwm, 3);
+static SENSOR_DEVICE_ATTR(pwm4, 0644,
+			show_pwm, set_pwm, 4);
+static SENSOR_DEVICE_ATTR(pwm5, 0644,
+			show_pwm, set_pwm, 5);
+static SENSOR_DEVICE_ATTR(pwm6, 0644,
+			show_pwm, set_pwm, 6);
+static SENSOR_DEVICE_ATTR(pwm7, 0644,
+			show_pwm, set_pwm, 7);
+static struct attribute *pwm_dev_attrs[] = {
+	&sensor_dev_attr_pwm0.dev_attr.attr,
+	&sensor_dev_attr_pwm1.dev_attr.attr,
+	&sensor_dev_attr_pwm2.dev_attr.attr,
+	&sensor_dev_attr_pwm3.dev_attr.attr,
+	&sensor_dev_attr_pwm4.dev_attr.attr,
+	&sensor_dev_attr_pwm5.dev_attr.attr,
+	&sensor_dev_attr_pwm6.dev_attr.attr,
+	&sensor_dev_attr_pwm7.dev_attr.attr,
+	NULL,
+};
+
+static const struct attribute_group pwm_dev_group = {
+	.attrs = pwm_dev_attrs,
+	.is_visible = pwm_is_visible,
+};
+
+static SENSOR_DEVICE_ATTR(fan0_input, 0444,
+		show_rpm, NULL, 0);
+static SENSOR_DEVICE_ATTR(fan1_input, 0444,
+		show_rpm, NULL, 1);
+static SENSOR_DEVICE_ATTR(fan2_input, 0444,
+		show_rpm, NULL, 2);
+static SENSOR_DEVICE_ATTR(fan3_input, 0444,
+		show_rpm, NULL, 3);
+static SENSOR_DEVICE_ATTR(fan4_input, 0444,
+		show_rpm, NULL, 4);
+static SENSOR_DEVICE_ATTR(fan5_input, 0444,
+		show_rpm, NULL, 5);
+static SENSOR_DEVICE_ATTR(fan6_input, 0444,
+		show_rpm, NULL, 6);
+static SENSOR_DEVICE_ATTR(fan7_input, 0444,
+		show_rpm, NULL, 7);
+static SENSOR_DEVICE_ATTR(fan8_input, 0444,
+		show_rpm, NULL, 8);
+static SENSOR_DEVICE_ATTR(fan9_input, 0444,
+		show_rpm, NULL, 9);
+static SENSOR_DEVICE_ATTR(fan10_input, 0444,
+		show_rpm, NULL, 10);
+static SENSOR_DEVICE_ATTR(fan11_input, 0444,
+		show_rpm, NULL, 11);
+static SENSOR_DEVICE_ATTR(fan12_input, 0444,
+		show_rpm, NULL, 12);
+static SENSOR_DEVICE_ATTR(fan13_input, 0444,
+		show_rpm, NULL, 13);
+static SENSOR_DEVICE_ATTR(fan14_input, 0444,
+		show_rpm, NULL, 14);
+static SENSOR_DEVICE_ATTR(fan15_input, 0444,
+		show_rpm, NULL, 15);
+static struct attribute *fan_dev_attrs[] = {
+	&sensor_dev_attr_fan0_input.dev_attr.attr,
+	&sensor_dev_attr_fan1_input.dev_attr.attr,
+	&sensor_dev_attr_fan2_input.dev_attr.attr,
+	&sensor_dev_attr_fan3_input.dev_attr.attr,
+	&sensor_dev_attr_fan4_input.dev_attr.attr,
+	&sensor_dev_attr_fan5_input.dev_attr.attr,
+	&sensor_dev_attr_fan6_input.dev_attr.attr,
+	&sensor_dev_attr_fan7_input.dev_attr.attr,
+	&sensor_dev_attr_fan8_input.dev_attr.attr,
+	&sensor_dev_attr_fan9_input.dev_attr.attr,
+	&sensor_dev_attr_fan10_input.dev_attr.attr,
+	&sensor_dev_attr_fan11_input.dev_attr.attr,
+	&sensor_dev_attr_fan12_input.dev_attr.attr,
+	&sensor_dev_attr_fan13_input.dev_attr.attr,
+	&sensor_dev_attr_fan14_input.dev_attr.attr,
+	&sensor_dev_attr_fan15_input.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group fan_dev_group = {
+	.attrs = fan_dev_attrs,
+	.is_visible = fan_dev_is_visible,
+};
+
+/*
+ * The clock type is type M :
+ * The PWM frequency = 24MHz / (type M clock division L bit *
+ * type M clock division H bit * (type M PWM period bit + 1))
+ */
+static void aspeed_create_type(struct aspeed_pwm_tacho_data *priv)
+{
+	priv->type_pwm_clock_division_h[TYPEM] = M_PWM_DIV_H;
+	priv->type_pwm_clock_division_l[TYPEM] = M_PWM_DIV_L;
+	priv->type_pwm_clock_unit[TYPEM] = M_PWM_PERIOD;
+	aspeed_set_pwm_clock_values(priv->regmap, TYPEM, M_PWM_DIV_H,
+				    M_PWM_DIV_L, M_PWM_PERIOD);
+	aspeed_set_tacho_type_enable(priv->regmap, TYPEM, true);
+	priv->type_fan_tach_clock_division[TYPEM] = M_TACH_CLK_DIV;
+	priv->type_fan_tach_unit[TYPEM] = M_TACH_UNIT;
+	aspeed_set_tacho_type_values(priv->regmap, TYPEM, M_TACH_MODE,
+				     M_TACH_UNIT, M_TACH_CLK_DIV);
+}
+
+static void aspeed_create_pwm_port(struct aspeed_pwm_tacho_data *priv,
+				   u8 pwm_port)
+{
+	aspeed_set_pwm_port_enable(priv->regmap, pwm_port, true);
+	priv->pwm_present[pwm_port] = true;
+
+	priv->pwm_port_type[pwm_port] = TYPEM;
+	aspeed_set_pwm_port_type(priv->regmap, pwm_port, TYPEM);
+
+	priv->pwm_port_fan_ctrl[pwm_port] = INIT_FAN_CTRL;
+	aspeed_set_pwm_port_fan_ctrl(priv, pwm_port, INIT_FAN_CTRL);
+}
+
+static void aspeed_create_fan_tach_channel(struct aspeed_pwm_tacho_data *priv,
+					   u8 *fan_tach_ch,
+					   int count,
+					   u8 pwm_source)
+{
+	u8 val, index;
+
+	for (val = 0; val < count; val++) {
+		index = fan_tach_ch[val];
+		aspeed_set_fan_tach_ch_enable(priv->regmap, index, true);
+		priv->fan_tach_present[index] = true;
+		priv->fan_tach_ch_source[index] = pwm_source;
+		aspeed_set_fan_tach_ch_source(priv->regmap, index, pwm_source);
+	}
+}
+
+static int aspeed_create_fan(struct device *dev,
+			     struct device_node *child,
+			     struct aspeed_pwm_tacho_data *priv)
+{
+	u8 *fan_tach_ch;
+	u32 pwm_port;
+	int ret, count;
+
+	ret = of_property_read_u32(child, "reg", &pwm_port);
+	if (ret)
+		return ret;
+	aspeed_create_pwm_port(priv, (u8)pwm_port);
+
+	count = of_property_count_u8_elems(child, "aspeed,fan-tach-ch");
+	if (count < 1)
+		return -EINVAL;
+	fan_tach_ch = devm_kzalloc(dev, sizeof(*fan_tach_ch) * count,
+				   GFP_KERNEL);
+	if (!fan_tach_ch)
+		return -ENOMEM;
+	ret = of_property_read_u8_array(child, "aspeed,fan-tach-ch",
+					fan_tach_ch, count);
+	if (ret)
+		return ret;
+	aspeed_create_fan_tach_channel(priv, fan_tach_ch, count, pwm_port);
+
+	return 0;
+}
+
+static int aspeed_pwm_tacho_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np, *child;
+	struct aspeed_pwm_tacho_data *priv;
+	void __iomem *regs;
+	struct resource *res;
+	struct device *hwmon;
+	struct clk *clk;
+	int ret;
+
+	np = dev->of_node;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENOENT;
+	regs = devm_ioremap_resource(dev, res);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+	priv->regmap = devm_regmap_init(dev, NULL, regs,
+			&aspeed_pwm_tacho_regmap_config);
+	if (IS_ERR(priv->regmap))
+		return PTR_ERR(priv->regmap);
+	regmap_write(priv->regmap, ASPEED_PTCR_TACH_SOURCE, 0);
+	regmap_write(priv->regmap, ASPEED_PTCR_TACH_SOURCE_EXT, 0);
+
+	clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(clk))
+		return -ENODEV;
+	priv->clk_freq = clk_get_rate(clk);
+	aspeed_set_clock_enable(priv->regmap, true);
+	aspeed_set_clock_source(priv->regmap, 0);
+
+	aspeed_create_type(priv);
+
+	for_each_child_of_node(np, child) {
+		ret = aspeed_create_fan(dev, child, priv);
+		of_node_put(child);
+		if (ret)
+			return ret;
+	}
+	of_node_put(np);
+
+	priv->groups[0] = &pwm_dev_group;
+	priv->groups[1] = &fan_dev_group;
+	priv->groups[2] = NULL;
+	hwmon = devm_hwmon_device_register_with_groups(dev,
+						       "aspeed_pwm_tacho",
+						       priv, priv->groups);
+
+	return PTR_ERR_OR_ZERO(hwmon);
+}
+
+static const struct of_device_id of_pwm_tacho_match_table[] = {
+	{ .compatible = "aspeed,ast2400-pwm-tacho", },
+	{ .compatible = "aspeed,ast2500-pwm-tacho", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, of_pwm_tacho_match_table);
+
+static struct platform_driver aspeed_pwm_tacho_driver = {
+	.probe		= aspeed_pwm_tacho_probe,
+	.driver		= {
+		.name	= "aspeed_pwm_tacho",
+		.of_match_table = of_pwm_tacho_match_table,
+	},
+};
+
+module_platform_driver(aspeed_pwm_tacho_driver);
+
+MODULE_AUTHOR("Jaghathiswari Rankappagounder Natarajan <jaghu@google.com>");
+MODULE_DESCRIPTION("ASPEED PWM and Fan Tacho device driver");
+MODULE_LICENSE("GPL");
