drivers: hwmon: Support for ASPEED PWM/Fan tach

The ASPEED AST2400/2500 PWM controller supports 8 PWM output ports.
The ASPEED AST2400/2500 Fan tach controller supports 16 tachometer
inputs.
The device driver matches on the device tree node. The configuration
values are read from the device tree and written to the respective
registers.
The driver provides a sysfs entries through which the user can
configure the duty-cycle value (ranging from 0 to 100 percent) and read
the fan tach rpm value.

Signed-off-by: Jaghathiswari Rankappagounder Natarajan <jaghu@google.com>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

4 files changed, 867 insertions, 0 deletions

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 0649d53f3d16..337e9078df0a 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 5509edf6186a..d2bdccc000e6 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..48403a2115be
--- /dev/null
+++ b/drivers/hwmon/aspeed-pwm-tacho.c
@@ -0,0 +1,835 @@
+/*
+ * 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
+
+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 = (void __iomem *)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 = (void __iomem *)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, 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);
+
+	regmap_read(priv->regmap, ASPEED_PTCR_RESULT, &val);
+	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, (__force void *)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");