[PATCH v2 4/4] hwmon: Support Aspeed AST2600 PWM/Fan tachometer

Troy Lee troy_lee at aspeedtech.com
Wed Jan 13 18:08:48 AEDT 2021


Add Aspeed AST2600 PWM/Fan tacho driver. AST2600 has 16 PWM channel and
16 FAN tacho channel.

Changes since v1:
- fixed review comments
- fixed double-looped calculation of div_h and div_l
- moving configuration to device tree
- register hwmon driver with devm_hwmon_device_register_with_info()

Signed-off-by: Troy Lee <troy_lee at aspeedtech.com>
---
 drivers/hwmon/Kconfig                |  10 +
 drivers/hwmon/Makefile               |   1 +
 drivers/hwmon/aspeed2600-pwm-tacho.c | 756 +++++++++++++++++++++++++++
 3 files changed, 767 insertions(+)
 create mode 100644 drivers/hwmon/aspeed2600-pwm-tacho.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 1ecf697d8d99..98f89f703161 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -400,6 +400,16 @@ config SENSORS_ASPEED
 	  This driver can also be built as a module. If so, the module
 	  will be called aspeed_pwm_tacho.
 
+config SENSORS_ASPEED2600_PWM_TACHO
+	tristate "ASPEED AST2600 PWM and Fan Tachometer"
+	depends on THERMAL || THERMAL=n
+	help
+	  This driver provides support for ASPEED AST2600 PWM
+	  and Fan Tacho controllers.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called aspeed2600-pwm-tacho.
+
 config SENSORS_ATXP1
 	tristate "Attansic ATXP1 VID controller"
 	depends on I2C
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 09a86c5e1d29..1a415d493ffc 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_SENSORS_ARM_SCPI)	+= scpi-hwmon.o
 obj-$(CONFIG_SENSORS_AS370)	+= as370-hwmon.o
 obj-$(CONFIG_SENSORS_ASC7621)	+= asc7621.o
 obj-$(CONFIG_SENSORS_ASPEED)	+= aspeed-pwm-tacho.o
+obj-$(CONFIG_SENSORS_ASPEED2600_PWM_TACHO)	+= aspeed2600-pwm-tacho.o
 obj-$(CONFIG_SENSORS_ATXP1)	+= atxp1.o
 obj-$(CONFIG_SENSORS_AXI_FAN_CONTROL) += axi-fan-control.o
 obj-$(CONFIG_SENSORS_BT1_PVT)	+= bt1-pvt.o
diff --git a/drivers/hwmon/aspeed2600-pwm-tacho.c b/drivers/hwmon/aspeed2600-pwm-tacho.c
new file mode 100644
index 000000000000..150cf65243ee
--- /dev/null
+++ b/drivers/hwmon/aspeed2600-pwm-tacho.c
@@ -0,0 +1,756 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) ASPEED Technology 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/errno.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/reset.h>
+#include <linux/regmap.h>
+#include <linux/thermal.h>
+/**********************************************************
+ * PWM HW register offset define
+ *********************************************************/
+/* PWM Control Register */
+#define ASPEED_PWM_CTRL_CH(ch)			(((ch) * 0x10) + 0x00)
+/* PWM Duty Cycle Register */
+#define ASPEED_PWM_DUTY_CYCLE_CH(ch)		(((ch) * 0x10) + 0x04)
+/* TACH Control Register */
+#define ASPEED_TACHO_CTRL_CH(ch)		(((ch) * 0x10) + 0x08)
+/* TACH Status Register */
+#define ASPEED_TACHO_STS_CH(x)			(((x) * 0x10) + 0x0C)
+
+/**********************************************************
+ * PWM register Bit field
+ *********************************************************/
+/*PWM_CTRL */
+#define PWM_LOAD_SEL_AS_WDT_BIT		(19)	/* load selection as WDT */
+#define PWM_DUTY_LOAD_AS_WDT_EN		BIT(18)	/* enable PWM duty load as WDT */
+#define PWM_DUTY_SYNC_DIS		BIT(17)	/* disable PWM duty sync */
+#define PWM_CLK_ENABLE			BIT(16)	/* enable PWM clock */
+#define PWM_LEVEL_OUTPUT		BIT(15)	/* output PWM level */
+#define PWM_INVERSE			BIT(14) /* inverse PWM pin */
+#define PWM_OPEN_DRAIN_EN		BIT(13)	/* enable open-drain */
+#define PWM_PIN_EN			BIT(12) /* enable PWM pin */
+#define PWM_CLK_DIV_H_MASK		(0xf << 8) /* PWM clock division H bit [3:0] */
+#define PWM_CLK_DIV_L_MASK		(0xff)	/* PWM clock division H bit [3:0] */
+/* [19] */
+#define LOAD_SEL_FALLING 0
+#define LOAD_SEL_RIGING  1
+
+/*PWM_DUTY_CYCLE */
+#define PWM_PERIOD_BIT			(24)		/* pwm period bit [7:0] */
+#define PWM_PERIOD_BIT_MASK		(0xff << 24)	/* pwm period bit [7:0] */
+#define PWM_RISING_FALLING_AS_WDT_BIT	(16)
+#define PWM_RISING_FALLING_AS_WDT_MASK	(0xff << 16)	/* rising/falling point bit [7:0] as WDT */
+#define PWM_RISING_FALLING_MASK		(0xffff)
+#define PWM_FALLING_POINT_BIT		(8)		/* pwm falling point bit [7:0] */
+#define PWM_RISING_POINT_BIT		(0)		/* pwm rising point bit [7:0] */
+/* [31:24] */
+#define DEFAULT_PWM_PERIOD 0xff
+
+/*PWM_TACHO_CTRL */
+#define TACHO_IER				BIT(31)	/* enable tacho interrupt */
+#define TACHO_INVERS_LIMIT			BIT(30) /* inverse tacho limit comparison */
+#define TACHO_LOOPBACK				BIT(29) /* tacho loopback */
+#define TACHO_ENABLE				BIT(28)	/* enable tacho */
+#define TACHO_DEBOUNCE_MASK			(0x3 << 26) /* tacho de-bounce */
+#define TACHO_DEBOUNCE_BIT			(26) /* tacho de-bounce */
+#define TECHIO_EDGE_MASK			(0x3 << 24) /* tacho edge */
+#define TECHIO_EDGE_BIT				(24) /* tacho edge */
+#define TACHO_CLK_DIV_T_MASK			(0xf << 20)
+#define TACHO_CLK_DIV_BIT			(20)
+#define TACHO_THRESHOLD_MASK			(0xfffff)	/* tacho threshold bit */
+/* [27:26] */
+#define DEBOUNCE_3_CLK 0x00 /* 10b */
+#define DEBOUNCE_2_CLK 0x01 /* 10b */
+#define DEBOUNCE_1_CLK 0x02 /* 10b */
+#define DEBOUNCE_0_CLK 0x03 /* 10b */
+/* [25:24] */
+#define F2F_EDGES 0x00 /* 10b */
+#define R2R_EDGES 0x01 /* 10b */
+#define BOTH_EDGES 0x02 /* 10b */
+/* [23:20] */
+/* Cover rpm range 5~5859375 */
+#define  DEFAULT_TACHO_DIV 5
+
+/*PWM_TACHO_STS */
+#define  TACHO_ISR		BIT(31)	/* interrupt status and clear */
+#define  PWM_OUT		BIT(25)	/* pwm_out */
+#define  PWM_OEN		BIT(24)	/* pwm_oeN */
+#define  TACHO_DEB_INPUT	BIT(23)	/* tacho deB input */
+#define  TACHO_RAW_INPUT	BIT(22) /* tacho raw input */
+#define  TACHO_VALUE_UPDATE	BIT(21)	/* tacho value updated since the last read */
+#define  TACHO_FULL_MEASUREMENT	BIT(20) /* tacho full measurement */
+#define  TACHO_VALUE_MASK	0xfffff	/* tacho value bit [19:0] */
+/**********************************************************
+ * Software setting
+ *********************************************************/
+#define DEFAULT_TARGET_PWM_FREQ		25000
+#define DEFAULT_FAN_PULSE_PR		2
+#define DEFAULT_WDT_RISING_FALLING_PT	0x10
+#define DEFAULT_RISING_PT		0x00
+#define DEFAULT_FALLING_PT		0x0a
+#define MAX_CDEV_NAME_LEN		16
+
+struct aspeed_pwm_channel_params {
+	int target_freq;
+	int pwm_freq;
+	int load_wdt_rising_falling_pt;
+	int load_wdt_selection;		/* 0: rising , 1: falling */
+	int load_wdt_enable;
+	int duty_sync_disable;
+	int inverse_pin;
+	u8 falling;
+};
+
+static struct aspeed_pwm_channel_params default_pwm_params[16];
+
+struct aspeed_tacho_channel_params {
+	int limited_inverse;
+	u16 threshold;
+	u8 tacho_edge;
+	u8 tacho_debounce;
+	u8 pulse_pr;
+	u32 divide;
+};
+
+static struct aspeed_tacho_channel_params default_tacho_params[16];
+
+struct aspeed_pwm_tachometer_data {
+	struct regmap *regmap;
+	unsigned long clk_freq;
+	struct reset_control *reset;
+	bool pwm_present[16];
+	bool fan_tach_present[16];
+	struct aspeed_pwm_channel_params *pwm_channel;
+	struct aspeed_tacho_channel_params *tacho_channel;
+	/* for thermal */
+	struct aspeed_cooling_device *cdev[8];
+};
+
+struct aspeed_cooling_device {
+	char name[16];
+	struct aspeed_pwm_tachometer_data *priv;
+	struct thermal_cooling_device *tcdev;
+	int pwm_channel;
+	u8 *cooling_levels;
+	u8 max_state;
+	u8 cur_state;
+};
+
+static int regmap_aspeed_pwm_tachometer_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_tachometer_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_tachometer_regmap_config = {
+	.reg_bits = 32,
+	.val_bits = 32,
+	.reg_stride = 4,
+	.max_register = 0x100,
+	.reg_write = regmap_aspeed_pwm_tachometer_reg_write,
+	.reg_read = regmap_aspeed_pwm_tachometer_reg_read,
+	.fast_io = true,
+};
+
+static void aspeed_set_pwm_channel_enable(struct regmap *regmap, u8 pwm_channel,
+				       bool enable)
+{
+	regmap_update_bits(regmap, ASPEED_PWM_CTRL_CH(pwm_channel),
+			   PWM_CLK_ENABLE | PWM_PIN_EN,
+			   enable ? PWM_CLK_ENABLE | PWM_PIN_EN : 0);
+}
+
+static void aspeed_set_fan_tach_ch_enable(struct aspeed_pwm_tachometer_data *priv, u8 fan_tach_ch,
+					  bool enable, u32 tacho_div)
+{
+	u32 reg_value;
+
+	if (enable) {
+		/* divide = 2^(tacho_div*2) */
+		priv->tacho_channel[fan_tach_ch].divide = 1 << (tacho_div << 1);
+
+		reg_value = TACHO_ENABLE |
+				(priv->tacho_channel[fan_tach_ch].tacho_edge << TECHIO_EDGE_BIT) |
+				(tacho_div << TACHO_CLK_DIV_BIT) |
+				(priv->tacho_channel[fan_tach_ch].tacho_debounce << TACHO_DEBOUNCE_BIT);
+
+		if (priv->tacho_channel[fan_tach_ch].limited_inverse)
+			reg_value |= TACHO_INVERS_LIMIT;
+
+		if (priv->tacho_channel[fan_tach_ch].threshold)
+			reg_value |= (TACHO_IER | priv->tacho_channel[fan_tach_ch].threshold);
+
+		regmap_write(priv->regmap, ASPEED_TACHO_CTRL_CH(fan_tach_ch), reg_value);
+	} else
+		regmap_update_bits(priv->regmap, ASPEED_TACHO_CTRL_CH(fan_tach_ch),  TACHO_ENABLE, 0);
+}
+
+/*
+ * The PWM frequency = HCLK(200Mhz) / (clock division L bit *
+ * clock division H bit * (period bit + 1))
+ */
+static void aspeed_set_pwm_channel_fan_ctrl(struct device *dev,
+					   struct aspeed_pwm_tachometer_data *priv,
+					   u8 index, u8 fan_ctrl)
+{
+	u32 duty_value,	ctrl_value;
+	u32 target_div, div_h, div_l, cal_freq;
+	u32 tmp_div_h, tmp_div_l, diff, min_diff = INT_MAX;
+
+	if (fan_ctrl == 0) {
+		aspeed_set_pwm_channel_enable(priv->regmap, index, false);
+		return;
+	}
+
+	cal_freq = priv->clk_freq / (DEFAULT_PWM_PERIOD + 1);
+	target_div = DIV_ROUND_UP(cal_freq, priv->pwm_channel[index].target_freq);
+
+	/* calculate for target frequence */
+	for (tmp_div_h = 0; tmp_div_h < 0x10; tmp_div_h++) {
+		tmp_div_l = target_div / BIT(tmp_div_h) - 1;
+
+		if (tmp_div_l < 0 || tmp_div_l > 255)
+			continue;
+
+		diff = priv->pwm_channel[index].target_freq - cal_freq / (BIT(tmp_div_h) * (tmp_div_l + 1));
+		if (abs(diff) < abs(min_diff)) {
+			min_diff = diff;
+			div_l = tmp_div_l;
+			div_h = tmp_div_h;
+
+			if (diff == 0)
+				break;
+		}
+	}
+
+	priv->pwm_channel[index].pwm_freq = cal_freq / (BIT(div_h) * (div_l + 1));
+	dev_info(dev, "div h %x, l : %x pwm out clk %d\n", div_h, div_l,
+			priv->pwm_channel[index].pwm_freq);
+	dev_info(dev, "hclk %ld, target pwm freq %d, real pwm freq %d\n", priv->clk_freq,
+			priv->pwm_channel[index].target_freq, priv->pwm_channel[index].pwm_freq);
+
+	ctrl_value = (div_h << 8) | div_l;
+
+	duty_value = (DEFAULT_PWM_PERIOD << PWM_PERIOD_BIT) |
+		(0 << PWM_RISING_POINT_BIT) | (fan_ctrl << PWM_FALLING_POINT_BIT);
+
+	if (priv->pwm_channel[index].load_wdt_enable) {
+		ctrl_value |= PWM_DUTY_LOAD_AS_WDT_EN;
+		ctrl_value |= priv->pwm_channel[index].load_wdt_selection << PWM_LOAD_SEL_AS_WDT_BIT;
+		duty_value |= (priv->pwm_channel[index].load_wdt_rising_falling_pt << PWM_RISING_FALLING_AS_WDT_BIT);
+	}
+
+	if (priv->pwm_channel[index].inverse_pin)
+		ctrl_value |= PWM_INVERSE;
+	if (priv->pwm_channel[index].duty_sync_disable)
+		ctrl_value |= PWM_DUTY_SYNC_DIS;
+
+	regmap_write(priv->regmap, ASPEED_PWM_DUTY_CYCLE_CH(index), duty_value);
+	regmap_write(priv->regmap, ASPEED_PWM_CTRL_CH(index), ctrl_value);
+
+	aspeed_set_pwm_channel_enable(priv->regmap, index, true);
+}
+
+static int aspeed_get_fan_tach_ch_rpm(struct device *dev, struct aspeed_pwm_tachometer_data *priv,
+				      u8 fan_tach_ch)
+{
+	u32 raw_data, tach_div, clk_source, val;
+	int ret;
+
+	ret = regmap_read_poll_timeout(priv->regmap,
+				ASPEED_TACHO_STS_CH(fan_tach_ch),
+				val,
+				(val & TACHO_FULL_MEASUREMENT),
+				1000,
+				10000);
+
+	/* return -ETIMEDOUT if we didn't get an answer. */
+	if (ret)
+		return ret;
+
+	raw_data = val & TACHO_VALUE_MASK;
+	if (raw_data == 0xfffff)
+		return 0;
+
+	raw_data += 1;
+
+	/*
+	 * We need the mode to determine if the raw_data is double (from
+	 * counting both edges).
+	 */
+	tach_div = raw_data * (priv->tacho_channel[fan_tach_ch].divide) * (priv->tacho_channel[fan_tach_ch].pulse_pr);
+
+	dev_dbg(dev, "clk %ld, raw_data %d , tach_div %d\n", priv->clk_freq, raw_data, tach_div);
+	clk_source = priv->clk_freq;
+
+	return ((clk_source / tach_div) * 60);
+
+}
+
+static int set_pwm(struct device *dev, int index, long fan_ctrl)
+{
+	struct aspeed_pwm_tachometer_data *priv = dev_get_drvdata(dev);
+	u8 org_falling = priv->pwm_channel[index].falling;
+
+	if (fan_ctrl > DEFAULT_PWM_PERIOD || fan_ctrl < 0)
+		return -EINVAL;
+
+	if (priv->pwm_channel[index].falling == fan_ctrl)
+		return 0;
+
+	priv->pwm_channel[index].falling = fan_ctrl;
+
+	if (fan_ctrl == 0)
+		aspeed_set_pwm_channel_enable(priv->regmap, index, false);
+	else {
+		if (fan_ctrl == DEFAULT_PWM_PERIOD)
+			regmap_update_bits(priv->regmap,
+					   ASPEED_PWM_DUTY_CYCLE_CH(index),
+					   GENMASK(15, 0), 0);
+		else
+			regmap_update_bits(priv->regmap,
+					   ASPEED_PWM_DUTY_CYCLE_CH(index),
+					   GENMASK(15, 8),
+					   (fan_ctrl << PWM_FALLING_POINT_BIT));
+	}
+
+	if (org_falling == 0)
+		aspeed_set_pwm_channel_enable(priv->regmap, index, true);
+
+	return 0;
+}
+
+static void aspeed_create_pwm_channel(struct device *dev, struct aspeed_pwm_tachometer_data *priv,
+			   u8 pwm_channel)
+{
+	priv->pwm_present[pwm_channel] = true;
+
+	/* use default */
+	aspeed_set_pwm_channel_fan_ctrl(dev,
+					priv,
+					pwm_channel,
+					priv->pwm_channel[pwm_channel].falling);
+}
+
+static void aspeed_create_fan_tach_channel(struct aspeed_pwm_tachometer_data *priv,
+					   u8 *fan_tach_ch, int count,
+					   u32 fan_pulse_pr, u32 tacho_div)
+{
+	u8 val, index;
+
+	for (val = 0; val < count; val++) {
+		index = fan_tach_ch[val];
+		priv->fan_tach_present[index] = true;
+		priv->tacho_channel[index].pulse_pr = fan_pulse_pr;
+		priv->tacho_channel[index].limited_inverse = 0;
+		priv->tacho_channel[index].threshold = 0;
+		priv->tacho_channel[index].tacho_edge = F2F_EDGES;
+		priv->tacho_channel[index].tacho_debounce = DEBOUNCE_3_CLK;
+		aspeed_set_fan_tach_ch_enable(priv, index, true, tacho_div);
+	}
+}
+
+static int
+aspeed_pwm_cz_get_max_state(struct thermal_cooling_device *tcdev,
+			    unsigned long *state)
+{
+	struct aspeed_cooling_device *cdev = tcdev->devdata;
+
+	*state = cdev->max_state;
+
+	return 0;
+}
+
+static int
+aspeed_pwm_cz_get_cur_state(struct thermal_cooling_device *tcdev,
+			    unsigned long *state)
+{
+	struct aspeed_cooling_device *cdev = tcdev->devdata;
+
+	*state = cdev->cur_state;
+
+	return 0;
+}
+
+static int
+aspeed_pwm_cz_set_cur_state(struct thermal_cooling_device *tcdev,
+			    unsigned long state)
+{
+	struct aspeed_cooling_device *cdev = tcdev->devdata;
+
+	if (state > cdev->max_state)
+		return -EINVAL;
+
+	cdev->cur_state = state;
+	cdev->priv->pwm_channel[cdev->pwm_channel].falling =
+					cdev->cooling_levels[cdev->cur_state];
+	aspeed_set_pwm_channel_fan_ctrl(&tcdev->device, cdev->priv, cdev->pwm_channel,
+				     cdev->cooling_levels[cdev->cur_state]);
+
+	return 0;
+}
+
+static const struct thermal_cooling_device_ops aspeed_pwm_cool_ops = {
+	.get_max_state = aspeed_pwm_cz_get_max_state,
+	.get_cur_state = aspeed_pwm_cz_get_cur_state,
+	.set_cur_state = aspeed_pwm_cz_set_cur_state,
+};
+
+static int aspeed_create_pwm_cooling(struct device *dev,
+				     struct device_node *child,
+				     struct aspeed_pwm_tachometer_data *priv,
+				     u32 pwm_channel, u8 num_levels)
+{
+	int ret;
+	struct aspeed_cooling_device *cdev;
+
+	cdev = devm_kzalloc(dev, sizeof(*cdev), GFP_KERNEL);
+	if (!cdev)
+		return -ENOMEM;
+
+	cdev->cooling_levels = devm_kzalloc(dev, num_levels, GFP_KERNEL);
+	if (!cdev->cooling_levels)
+		return -ENOMEM;
+
+	cdev->max_state = num_levels - 1;
+	ret = of_property_read_u8_array(child, "cooling-levels",
+					cdev->cooling_levels,
+					num_levels);
+	if (ret) {
+		dev_err(dev, "Property 'cooling-levels' cannot be read.\n");
+		return ret;
+	}
+	snprintf(cdev->name, MAX_CDEV_NAME_LEN, "%s%d", child->name, pwm_channel);
+
+	cdev->tcdev = thermal_of_cooling_device_register(child,
+							 cdev->name,
+							 cdev,
+							 &aspeed_pwm_cool_ops);
+	if (IS_ERR(cdev->tcdev))
+		return PTR_ERR(cdev->tcdev);
+
+	cdev->priv = priv;
+	cdev->pwm_channel = pwm_channel;
+
+	priv->cdev[pwm_channel] = cdev;
+
+	return 0;
+}
+
+static int aspeed_pwm_create_fan(struct device *dev,
+			     struct device_node *child,
+			     struct aspeed_pwm_tachometer_data *priv)
+{
+	u8 *fan_tach_ch;
+	u32 fan_pulse_pr;
+	u32 tacho_div;
+	u32 pwm_channel;
+	u32 target_pwm_freq = 0;
+	u8 val;
+	int ret, count;
+
+	ret = of_property_read_u32(child, "reg", &pwm_channel);
+	if (ret)
+		return ret;
+	else if (pwm_channel > 0x0f)
+		return -EINVAL;
+
+	ret = of_property_read_u32(child, "aspeed,pwm-freq", &target_pwm_freq);
+	if (ret)
+		target_pwm_freq = DEFAULT_TARGET_PWM_FREQ;
+
+	priv->pwm_channel[pwm_channel].target_freq = target_pwm_freq;
+
+	priv->pwm_channel[pwm_channel].load_wdt_enable = of_property_read_bool(child,
+			"aspeed,enable-pwm-duty-load-wdt");
+	priv->pwm_channel[pwm_channel].load_wdt_selection = of_property_read_bool(child,
+			"aspeed,wdt-selection-rising");
+	priv->pwm_channel[pwm_channel].duty_sync_disable = of_property_read_bool(child,
+			"aspeed,disable-duty-instant-change");
+	priv->pwm_channel[pwm_channel].inverse_pin = of_property_read_bool(child,
+			"aspeed,inverse-pin");
+
+	ret = of_property_read_u8(child, "aspeed,wdt-rising-falling-point", &val);
+	if (ret)
+		val = DEFAULT_WDT_RISING_FALLING_PT;
+	priv->pwm_channel[pwm_channel].load_wdt_rising_falling_pt = val;
+
+	ret = of_property_read_u8(child, "aspeed,falling-point", &val);
+	if (ret)
+		val = DEFAULT_FALLING_PT;
+	priv->pwm_channel[pwm_channel].falling = val;
+
+	aspeed_create_pwm_channel(dev, priv, (u8)pwm_channel);
+
+	ret = of_property_count_u8_elems(child, "cooling-levels");
+	if (ret > 0) {
+		if (IS_ENABLED(CONFIG_THERMAL)) {
+			ret = aspeed_create_pwm_cooling(dev, child, priv, pwm_channel,
+							ret);
+			if (ret)
+				return ret;
+		}
+	}
+
+	count = of_property_count_u8_elems(child, "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, "fan-tach-ch",
+					fan_tach_ch, count);
+	if (ret)
+		return ret;
+
+	ret = of_property_read_u32(child, "pulses-per-revolution", &fan_pulse_pr);
+	if (ret)
+		fan_pulse_pr = DEFAULT_FAN_PULSE_PR;
+
+	ret = of_property_read_u32(child, "aspeed,tacho-div", &tacho_div);
+	if (ret)
+		tacho_div = DEFAULT_TACHO_DIV;
+
+	aspeed_create_fan_tach_channel(priv, fan_tach_ch, count, fan_pulse_pr, tacho_div);
+
+	return 0;
+}
+
+static umode_t aspeed_pwm_tacho_is_visible(const void *data, enum hwmon_sensor_types type,
+					u32 attr, int channel)
+{
+	const struct aspeed_pwm_tachometer_data *priv = data;
+
+	switch (type) {
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_input:
+			if (!priv->pwm_present[channel])
+				return 0;
+			return 0644;
+		default:
+			return 0;
+		}
+		break;
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_input:
+			if (!priv->fan_tach_present[channel])
+				return 0;
+			return 0444;
+		default:
+			return 0;
+		}
+	default:
+		return 0;
+	}
+}
+
+int aspeed_pwm_tacho_read(struct device *dev, enum hwmon_sensor_types type,
+			u32 attr, int channel, long *val)
+{
+	struct aspeed_pwm_tachometer_data *priv = dev_get_drvdata(dev);
+	long rpm;
+
+	switch (type) {
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_input:
+			*val = priv->pwm_channel[channel].falling;
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
+		break;
+	case hwmon_fan:
+		switch (attr) {
+		case hwmon_fan_input:
+			rpm = aspeed_get_fan_tach_ch_rpm(dev, priv, channel);
+			if (rpm < 0)
+				return rpm;
+			*val = rpm;
+			break;
+		default:
+			return -EOPNOTSUPP;
+		}
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return 0;
+}
+
+int aspeed_pwm_tacho_write(struct device *dev, enum hwmon_sensor_types type,
+			u32 attr, int channel, long val)
+{
+	switch (type) {
+	case hwmon_pwm:
+		switch (attr) {
+		case hwmon_pwm_input:
+			return set_pwm(dev, channel, val);
+		default:
+			return -EOPNOTSUPP;
+		}
+		break;
+	default:
+		return -EOPNOTSUPP;
+	}
+	return -EOPNOTSUPP;
+}
+
+static const struct hwmon_ops aspeed_pwm_hwmon_ops = {
+	.is_visible = aspeed_pwm_tacho_is_visible,
+	.read = aspeed_pwm_tacho_read,
+	.write = aspeed_pwm_tacho_write,
+};
+
+static const struct hwmon_channel_info *aspeed_pwm_hwmon_info[] = {
+	HWMON_CHANNEL_INFO(pwm,
+			HWMON_PWM_INPUT,
+			HWMON_PWM_INPUT,
+			HWMON_PWM_INPUT,
+			HWMON_PWM_INPUT,
+			HWMON_PWM_INPUT,
+			HWMON_PWM_INPUT,
+			HWMON_PWM_INPUT,
+			HWMON_PWM_INPUT,
+			HWMON_PWM_INPUT,
+			HWMON_PWM_INPUT,
+			HWMON_PWM_INPUT,
+			HWMON_PWM_INPUT,
+			HWMON_PWM_INPUT,
+			HWMON_PWM_INPUT,
+			HWMON_PWM_INPUT,
+			HWMON_PWM_INPUT),
+	HWMON_CHANNEL_INFO(fan,
+			HWMON_F_INPUT,
+			HWMON_F_INPUT,
+			HWMON_F_INPUT,
+			HWMON_F_INPUT,
+			HWMON_F_INPUT,
+			HWMON_F_INPUT,
+			HWMON_F_INPUT,
+			HWMON_F_INPUT,
+			HWMON_F_INPUT,
+			HWMON_F_INPUT,
+			HWMON_F_INPUT,
+			HWMON_F_INPUT,
+			HWMON_F_INPUT,
+			HWMON_F_INPUT,
+			HWMON_F_INPUT,
+			HWMON_F_INPUT),
+	NULL,
+};
+
+static const struct hwmon_chip_info aspeed_pwm_chip_info = {
+	.ops = &aspeed_pwm_hwmon_ops,
+	.info = aspeed_pwm_hwmon_info,
+};
+
+static int aspeed_pwm_tachometer_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np, *child;
+	struct aspeed_pwm_tachometer_data *priv;
+	void __iomem *regs;
+	struct device *hwmon;
+	struct clk *clk;
+	int ret;
+
+	np = dev->of_node;
+
+	regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->pwm_channel = default_pwm_params;
+	priv->tacho_channel = default_tacho_params;
+	priv->regmap = devm_regmap_init(dev, NULL, (__force void *)regs,
+			&aspeed_pwm_tachometer_regmap_config);
+	if (IS_ERR(priv->regmap))
+		return PTR_ERR(priv->regmap);
+
+	clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(clk))
+		return -ENODEV;
+	priv->clk_freq = clk_get_rate(clk);
+
+	priv->reset = devm_reset_control_get(&pdev->dev, NULL);
+	if (IS_ERR(priv->reset)) {
+		dev_err(&pdev->dev, "can't get aspeed_pwm_tacho reset\n");
+		return PTR_ERR(priv->reset);
+	}
+
+	/* scu init */
+	reset_control_assert(priv->reset);
+	reset_control_deassert(priv->reset);
+
+	for_each_child_of_node(np, child) {
+		ret = aspeed_pwm_create_fan(dev, child, priv);
+		if (ret) {
+			of_node_put(child);
+			return ret;
+		}
+	}
+
+	dev_info(dev, "pwm tach probe done\n");
+	hwmon = devm_hwmon_device_register_with_info(dev, "aspeed_pwm_tachometer",
+			priv, &aspeed_pwm_chip_info, NULL);
+
+	return PTR_ERR_OR_ZERO(hwmon);
+}
+
+static const struct of_device_id of_pwm_tachometer_match_table[] = {
+	{ .compatible = "aspeed,ast2600-pwm-tachometer", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, of_pwm_tachometer_match_table);
+
+static struct platform_driver aspeed_pwm_tachometer_driver = {
+	.probe		= aspeed_pwm_tachometer_probe,
+	.driver		= {
+		.name	= "aspeed_pwm_tachometer",
+		.of_match_table = of_pwm_tachometer_match_table,
+	},
+};
+
+module_platform_driver(aspeed_pwm_tachometer_driver);
+
+MODULE_AUTHOR("Ryan Chen <ryan_chen at aspeedtech.com>");
+MODULE_DESCRIPTION("ASPEED PWM and Fan Tachometer device driver");
+MODULE_LICENSE("GPL");
-- 
2.25.1



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