[PATCH v12 3/3] hwmon: (aspeed-g6-pwm-tacho): Support for ASPEED g6 PWM/Fan tach

Billy Tsai
2024-01-08T07:44:01Z

The driver support two functions: PWM and Tachometer. The PWM feature can
handle up to 16 output ports, while the Tachometer can monitor to up to 16
input ports as well. This driver implements them by exposing two kernel
subsystems: PWM and HWMON. The PWM subsystem can be utilized alongside
existing drivers for controlling elements such as fans (pwm-fan.c),
beepers (pwm-beeper.c) and so on. Through the HWMON subsystem, the driver
provides sysfs interfaces for fan.

Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
---
Documentation/hwmon/aspeed-g6-pwm-tach.rst | 26 +
Documentation/hwmon/index.rst | 1 +
drivers/hwmon/Kconfig | 11 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/aspeed-g6-pwm-tach.c | 538 +++++++++++++++++++++
5 files changed, 577 insertions(+)
create mode 100644 Documentation/hwmon/aspeed-g6-pwm-tach.rst
create mode 100644 drivers/hwmon/aspeed-g6-pwm-tach.c

diff --git a/Documentation/hwmon/aspeed-g6-pwm-tach.rst b/Documentation/hwmon/aspeed-g6-pwm-tach.rst
new file mode 100644
index 000000000000..17398fe397fe
--- /dev/null
+++ b/Documentation/hwmon/aspeed-g6-pwm-tach.rst
@@ -0,0 +1,26 @@
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver aspeed-g6-pwm-tach
+=================================
+
+Supported chips:
+ ASPEED AST2600
+
+Authors:
+ <billy_tsai@aspeedtech.com>
+
+Description:
+------------
+This driver implements support for ASPEED AST2600 Fan Tacho controller.
+The 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.
+fanX_div rw Fan divisor: Supported value are power of 4 (1, 4, 16
+ 64, ... 4194304)
+ The larger divisor, the less rpm accuracy and the less
+ affected by fan signal glitch.
+=============== ======= ======================================================
diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 72f4e6065bae..f5ff380f7c9d 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -44,6 +44,7 @@ Hardware Monitoring Kernel Drivers
aquacomputer_d5next
asb100
asc7621
+ aspeed-g6-pwm-tach
aspeed-pwm-tacho
asus_ec_sensors
asus_wmi_sensors
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index cf27523eed5a..546a47a5880b 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -412,6 +412,17 @@ config SENSORS_ASPEED
This driver can also be built as a module. If so, the module
will be called aspeed_pwm_tacho.

+config SENSORS_ASPEED_G6
+ tristate "ASPEED g6 PWM and Fan tach driver"
+ depends on ARCH_ASPEED || COMPILE_TEST
+ depends on PWM
+ help
+ This driver provides support for ASPEED G6 PWM and Fan Tach
+ 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 e84bd9685b5c..92b150682828 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -55,6 +55,7 @@ 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-$(CONFIG_SENSORS_ASPEED_G6) += aspeed-g6-pwm-tach.o
obj-$(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/aspeed-g6-pwm-tach.c b/drivers/hwmon/aspeed-g6-pwm-tach.c
new file mode 100644
index 000000000000..996b77489710
--- /dev/null
+++ b/drivers/hwmon/aspeed-g6-pwm-tach.c
@@ -0,0 +1,538 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2021 Aspeed Technology Inc.
+ *
+ * PWM/TACH controller driver for Aspeed ast2600 SoCs.
+ * This drivers doesn't support earlier version of the IP.
+ *
+ * The hardware operates in time quantities of length
+ * Q := (DIV_L + 1) << DIV_H / input-clk
+ * The length of a PWM period is (DUTY_CYCLE_PERIOD + 1) * Q.
+ * The maximal value for DUTY_CYCLE_PERIOD is used here to provide
+ * a fine grained selection for the duty cycle.
+ *
+ * This driver uses DUTY_CYCLE_RISING_POINT = 0, so from the start of a
+ * period the output is active until DUTY_CYCLE_FALLING_POINT * Q. Note
+ * that if DUTY_CYCLE_RISING_POINT = DUTY_CYCLE_FALLING_POINT the output is
+ * always active.
+ *
+ * Register usage:
+ * PIN_ENABLE: When it is unset the pwm controller will emit inactive level to the external.
+ * Use to determine whether the PWM channel is enabled or disabled
+ * CLK_ENABLE: When it is unset the pwm controller will assert the duty counter reset and
+ * emit inactive level to the PIN_ENABLE mux after that the driver can still change the pwm period
+ * and duty and the value will apply when CLK_ENABLE be set again.
+ * Use to determine whether duty_cycle bigger than 0.
+ * PWM_ASPEED_CTRL_INVERSE: When it is toggled the output value will inverse immediately.
+ * PWM_ASPEED_DUTY_CYCLE_FALLING_POINT/PWM_ASPEED_DUTY_CYCLE_RISING_POINT: When these two
+ * values are equal it means the duty cycle = 100%.
+ *
+ * The glitch may generate at:
+ * - Enabled changing when the duty_cycle bigger than 0% and less than 100%.
+ * - Polarity changing when the duty_cycle bigger than 0% and less than 100%.
+ *
+ * Limitations:
+ * - When changing both duty cycle and period, we cannot prevent in
+ * software that the output might produce a period with mixed
+ * settings.
+ * - Disabling the PWM doesn't complete the current period.
+ *
+ * Improvements:
+ * - When only changing one of duty cycle or period, our pwm controller will not
+ * generate the glitch, the configure will change at next cycle of pwm.
+ * This improvement can disable/enable through PWM_ASPEED_CTRL_DUTY_SYNC_DISABLE.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/errno.h>
+#include <linux/hwmon.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/math64.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pwm.h>
+#include <linux/reset.h>
+#include <linux/sysfs.h>
+
+/* The channel number of Aspeed pwm controller */
+#define PWM_ASPEED_NR_PWMS 16
+/* PWM Control Register */
+#define PWM_ASPEED_CTRL(ch) ((ch) * 0x10 + 0x00)
+#define PWM_ASPEED_CTRL_LOAD_SEL_RISING_AS_WDT BIT(19)
+#define PWM_ASPEED_CTRL_DUTY_LOAD_AS_WDT_ENABLE BIT(18)
+#define PWM_ASPEED_CTRL_DUTY_SYNC_DISABLE BIT(17)
+#define PWM_ASPEED_CTRL_CLK_ENABLE BIT(16)
+#define PWM_ASPEED_CTRL_LEVEL_OUTPUT BIT(15)
+#define PWM_ASPEED_CTRL_INVERSE BIT(14)
+#define PWM_ASPEED_CTRL_OPEN_DRAIN_ENABLE BIT(13)
+#define PWM_ASPEED_CTRL_PIN_ENABLE BIT(12)
+#define PWM_ASPEED_CTRL_CLK_DIV_H GENMASK(11, 8)
+#define PWM_ASPEED_CTRL_CLK_DIV_L GENMASK(7, 0)
+
+/* PWM Duty Cycle Register */
+#define PWM_ASPEED_DUTY_CYCLE(ch) ((ch) * 0x10 + 0x04)
+#define PWM_ASPEED_DUTY_CYCLE_PERIOD GENMASK(31, 24)
+#define PWM_ASPEED_DUTY_CYCLE_POINT_AS_WDT GENMASK(23, 16)
+#define PWM_ASPEED_DUTY_CYCLE_FALLING_POINT GENMASK(15, 8)
+#define PWM_ASPEED_DUTY_CYCLE_RISING_POINT GENMASK(7, 0)
+
+/* PWM fixed value */
+#define PWM_ASPEED_FIXED_PERIOD FIELD_MAX(PWM_ASPEED_DUTY_CYCLE_PERIOD)
+
+/* The channel number of Aspeed tach controller */
+#define TACH_ASPEED_NR_TACHS 16
+/* TACH Control Register */
+#define TACH_ASPEED_CTRL(ch) (((ch) * 0x10) + 0x08)
+#define TACH_ASPEED_IER BIT(31)
+#define TACH_ASPEED_INVERS_LIMIT BIT(30)
+#define TACH_ASPEED_LOOPBACK BIT(29)
+#define TACH_ASPEED_ENABLE BIT(28)
+#define TACH_ASPEED_DEBOUNCE_MASK GENMASK(27, 26)
+#define TACH_ASPEED_DEBOUNCE_BIT 26
+#define TACH_ASPEED_IO_EDGE_MASK GENMASK(25, 24)
+#define TACH_ASPEED_IO_EDGE_BIT 24
+#define TACH_ASPEED_CLK_DIV_T_MASK GENMASK(23, 20)
+#define TACH_ASPEED_CLK_DIV_BIT 20
+#define TACH_ASPEED_THRESHOLD_MASK GENMASK(19, 0)
+/* [27:26] */
+#define DEBOUNCE_3_CLK 0x00
+#define DEBOUNCE_2_CLK 0x01
+#define DEBOUNCE_1_CLK 0x02
+#define DEBOUNCE_0_CLK 0x03
+/* [25:24] */
+#define F2F_EDGES 0x00
+#define R2R_EDGES 0x01
+#define BOTH_EDGES 0x02
+/* [23:20] */
+/* divisor = 4 to the nth power, n = register value */
+#define DEFAULT_TACH_DIV 1024
+#define DIV_TO_REG(divisor) (ilog2(divisor) >> 1)
+
+/* TACH Status Register */
+#define TACH_ASPEED_STS(ch) (((ch) * 0x10) + 0x0C)
+
+/*PWM_TACH_STS */
+#define TACH_ASPEED_ISR BIT(31)
+#define TACH_ASPEED_PWM_OUT BIT(25)
+#define TACH_ASPEED_PWM_OEN BIT(24)
+#define TACH_ASPEED_DEB_INPUT BIT(23)
+#define TACH_ASPEED_RAW_INPUT BIT(22)
+#define TACH_ASPEED_VALUE_UPDATE BIT(21)
+#define TACH_ASPEED_FULL_MEASUREMENT BIT(20)
+#define TACH_ASPEED_VALUE_MASK GENMASK(19, 0)
+/**********************************************************
+ * Software setting
+ *********************************************************/
+#define DEFAULT_FAN_PULSE_PR 2
+
+struct aspeed_pwm_tach_data {
+ struct device *dev;
+ void __iomem *base;
+ struct clk *clk;
+ struct reset_control *reset;
+ unsigned long clk_rate;
+ struct pwm_chip chip;
+ bool tach_present[TACH_ASPEED_NR_TACHS];
+ u32 tach_divisor;
+};
+
+static inline struct aspeed_pwm_tach_data *
+aspeed_pwm_chip_to_data(struct pwm_chip *chip)
+{
+ return container_of(chip, struct aspeed_pwm_tach_data, chip);
+}
+
+static int aspeed_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
+ struct pwm_state *state)
+{
+ struct aspeed_pwm_tach_data *priv = aspeed_pwm_chip_to_data(chip);
+ u32 hwpwm = pwm->hwpwm;
+ bool polarity, pin_en, clk_en;
+ u32 duty_pt, val;
+ u64 div_h, div_l, duty_cycle_period, dividend;
+
+ val = readl(priv->base + PWM_ASPEED_CTRL(hwpwm));
+ polarity = FIELD_GET(PWM_ASPEED_CTRL_INVERSE, val);
+ pin_en = FIELD_GET(PWM_ASPEED_CTRL_PIN_ENABLE, val);
+ clk_en = FIELD_GET(PWM_ASPEED_CTRL_CLK_ENABLE, val);
+ div_h = FIELD_GET(PWM_ASPEED_CTRL_CLK_DIV_H, val);
+ div_l = FIELD_GET(PWM_ASPEED_CTRL_CLK_DIV_L, val);
+ val = readl(priv->base + PWM_ASPEED_DUTY_CYCLE(hwpwm));
+ duty_pt = FIELD_GET(PWM_ASPEED_DUTY_CYCLE_FALLING_POINT, val);
+ duty_cycle_period = FIELD_GET(PWM_ASPEED_DUTY_CYCLE_PERIOD, val);
+ /*
+ * This multiplication doesn't overflow, the upper bound is
+ * 1000000000 * 256 * 256 << 15 = 0x1dcd650000000000
+ */
+ dividend = (u64)NSEC_PER_SEC * (div_l + 1) * (duty_cycle_period + 1)
+ << div_h;
+ state->period = DIV_ROUND_UP_ULL(dividend, priv->clk_rate);
+
+ if (clk_en && duty_pt) {
+ dividend = (u64)NSEC_PER_SEC * (div_l + 1) * duty_pt
+ << div_h;
+ state->duty_cycle = DIV_ROUND_UP_ULL(dividend, priv->clk_rate);
+ } else {
+ state->duty_cycle = clk_en ? state->period : 0;
+ }
+ state->polarity = polarity ? PWM_POLARITY_INVERSED : PWM_POLARITY_NORMAL;
+ state->enabled = pin_en;
+ return 0;
+}
+
+static int aspeed_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
+ const struct pwm_state *state)
+{
+ struct aspeed_pwm_tach_data *priv = aspeed_pwm_chip_to_data(chip);
+ u32 hwpwm = pwm->hwpwm, duty_pt, val;
+ u64 div_h, div_l, divisor, expect_period;
+ bool clk_en;
+
+ expect_period = div64_u64(ULLONG_MAX, (u64)priv->clk_rate);
+ expect_period = min(expect_period, state->period);
+ dev_dbg(chip->dev, "expect period: %lldns, duty_cycle: %lldns",
+ expect_period, state->duty_cycle);
+ /*
+ * Pick the smallest value for div_h so that div_l can be the biggest
+ * which results in a finer resolution near the target period value.
+ */
+ divisor = (u64)NSEC_PER_SEC * (PWM_ASPEED_FIXED_PERIOD + 1) *
+ (FIELD_MAX(PWM_ASPEED_CTRL_CLK_DIV_L) + 1);
+ div_h = order_base_2(DIV64_U64_ROUND_UP(priv->clk_rate * expect_period, divisor));
+ if (div_h > 0xf)
+ div_h = 0xf;
+
+ divisor = ((u64)NSEC_PER_SEC * (PWM_ASPEED_FIXED_PERIOD + 1)) << div_h;
+ div_l = div64_u64(priv->clk_rate * expect_period, divisor);
+
+ if (div_l == 0)
+ return -ERANGE;
+
+ div_l -= 1;
+
+ if (div_l > 255)
+ div_l = 255;
+
+ dev_dbg(chip->dev, "clk source: %ld div_h %lld, div_l : %lld\n",
+ priv->clk_rate, div_h, div_l);
+ /* duty_pt = duty_cycle * (PERIOD + 1) / period */
+ duty_pt = div64_u64(state->duty_cycle * priv->clk_rate,
+ (u64)NSEC_PER_SEC * (div_l + 1) << div_h);
+ dev_dbg(chip->dev, "duty_cycle = %lld, duty_pt = %d\n",
+ state->duty_cycle, duty_pt);
+
+ /*
+ * Fixed DUTY_CYCLE_PERIOD to its max value to get a
+ * fine-grained resolution for duty_cycle at the expense of a
+ * coarser period resolution.
+ */
+ val = readl(priv->base + PWM_ASPEED_DUTY_CYCLE(hwpwm));
+ val &= ~PWM_ASPEED_DUTY_CYCLE_PERIOD;
+ val |= FIELD_PREP(PWM_ASPEED_DUTY_CYCLE_PERIOD,
+ PWM_ASPEED_FIXED_PERIOD);
+ writel(val, priv->base + PWM_ASPEED_DUTY_CYCLE(hwpwm));
+
+ if (duty_pt == 0) {
+ /* emit inactive level and assert the duty counter reset */
+ clk_en = 0;
+ } else {
+ clk_en = 1;
+ if (duty_pt >= (PWM_ASPEED_FIXED_PERIOD + 1))
+ duty_pt = 0;
+ val = readl(priv->base + PWM_ASPEED_DUTY_CYCLE(hwpwm));
+ val &= ~(PWM_ASPEED_DUTY_CYCLE_RISING_POINT |
+ PWM_ASPEED_DUTY_CYCLE_FALLING_POINT);
+ val |= FIELD_PREP(PWM_ASPEED_DUTY_CYCLE_FALLING_POINT, duty_pt);
+ writel(val, priv->base + PWM_ASPEED_DUTY_CYCLE(hwpwm));
+ }
+
+ val = readl(priv->base + PWM_ASPEED_CTRL(hwpwm));
+ val &= ~(PWM_ASPEED_CTRL_CLK_DIV_H | PWM_ASPEED_CTRL_CLK_DIV_L |
+ PWM_ASPEED_CTRL_PIN_ENABLE | PWM_ASPEED_CTRL_CLK_ENABLE |
+ PWM_ASPEED_CTRL_INVERSE);
+ val |= FIELD_PREP(PWM_ASPEED_CTRL_CLK_DIV_H, div_h) |
+ FIELD_PREP(PWM_ASPEED_CTRL_CLK_DIV_L, div_l) |
+ FIELD_PREP(PWM_ASPEED_CTRL_PIN_ENABLE, state->enabled) |
+ FIELD_PREP(PWM_ASPEED_CTRL_CLK_ENABLE, clk_en) |
+ FIELD_PREP(PWM_ASPEED_CTRL_INVERSE, state->polarity);
+ writel(val, priv->base + PWM_ASPEED_CTRL(hwpwm));
+
+ return 0;
+}
+
+static const struct pwm_ops aspeed_pwm_ops = {
+ .apply = aspeed_pwm_apply,
+ .get_state = aspeed_pwm_get_state,
+};
+
+static void aspeed_tach_ch_enable(struct aspeed_pwm_tach_data *priv, u8 tach_ch,
+ bool enable)
+{
+ if (enable)
+ writel(readl(priv->base + TACH_ASPEED_CTRL(tach_ch)) |
+ TACH_ASPEED_ENABLE,
+ priv->base + TACH_ASPEED_CTRL(tach_ch));
+ else
+ writel(readl(priv->base + TACH_ASPEED_CTRL(tach_ch)) &
+ ~TACH_ASPEED_ENABLE,
+ priv->base + TACH_ASPEED_CTRL(tach_ch));
+}
+
+static int aspeed_tach_val_to_rpm(struct aspeed_pwm_tach_data *priv, u32 tach_val)
+{
+ u64 rpm;
+ u32 tach_div;
+
+ tach_div = tach_val * priv->tach_divisor * DEFAULT_FAN_PULSE_PR;
+
+ dev_dbg(priv->dev, "clk %ld, tach_val %d , tach_div %d\n",
+ priv->clk_rate, tach_val, tach_div);
+
+ rpm = (u64)priv->clk_rate * 60;
+ do_div(rpm, tach_div);
+
+ return (int)rpm;
+}
+
+static int aspeed_get_fan_tach_ch_rpm(struct aspeed_pwm_tach_data *priv,
+ u8 fan_tach_ch)
+{
+ u32 val;
+
+ val = readl(priv->base + TACH_ASPEED_STS(fan_tach_ch));
+
+ if (!(val & TACH_ASPEED_FULL_MEASUREMENT))
+ return 0;
+ val = FIELD_GET(TACH_ASPEED_VALUE_MASK, val);
+ return aspeed_tach_val_to_rpm(priv, val);
+}
+
+static int aspeed_tach_hwmon_read(struct device *dev,
+ enum hwmon_sensor_types type, u32 attr,
+ int channel, long *val)
+{
+ struct aspeed_pwm_tach_data *priv = dev_get_drvdata(dev);
+ u32 reg_val;
+
+ switch (attr) {
+ case hwmon_fan_input:
+ *val = aspeed_get_fan_tach_ch_rpm(priv, channel);
+ break;
+ case hwmon_fan_div:
+ reg_val = readl(priv->base + TACH_ASPEED_CTRL(channel));
+ reg_val = FIELD_GET(TACH_ASPEED_CLK_DIV_T_MASK, reg_val);
+ *val = BIT(reg_val << 1);
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+ return 0;
+}
+
+static int aspeed_tach_hwmon_write(struct device *dev,
+ enum hwmon_sensor_types type, u32 attr,
+ int channel, long val)
+{
+ struct aspeed_pwm_tach_data *priv = dev_get_drvdata(dev);
+ u32 reg_val;
+
+ switch (attr) {
+ case hwmon_fan_div:
+ if (!is_power_of_2(val) || (ilog2(val) % 2) ||
+ DIV_TO_REG(val) > 0xb)
+ return -EINVAL;
+ priv->tach_divisor = val;
+ reg_val = readl(priv->base + TACH_ASPEED_CTRL(channel));
+ reg_val &= ~TACH_ASPEED_CLK_DIV_T_MASK;
+ reg_val |= FIELD_PREP(TACH_ASPEED_CLK_DIV_T_MASK,
+ DIV_TO_REG(priv->tach_divisor));
+ writel(reg_val, priv->base + TACH_ASPEED_CTRL(channel));
+ break;
+ default:
+ return -EOPNOTSUPP;
+ }
+
+ return 0;
+}
+
+static umode_t aspeed_tach_dev_is_visible(const void *drvdata,
+ enum hwmon_sensor_types type,
+ u32 attr, int channel)
+{
+ const struct aspeed_pwm_tach_data *priv = drvdata;
+
+ if (!priv->tach_present[channel])
+ return 0;
+ switch (attr) {
+ case hwmon_fan_input:
+ return 0444;
+ case hwmon_fan_div:
+ return 0644;
+ }
+ return 0;
+}
+
+static const struct hwmon_ops aspeed_tach_ops = {
+ .is_visible = aspeed_tach_dev_is_visible,
+ .read = aspeed_tach_hwmon_read,
+ .write = aspeed_tach_hwmon_write,
+};
+
+static const struct hwmon_channel_info *aspeed_tach_info[] = {
+ HWMON_CHANNEL_INFO(fan, HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+ HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+ HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+ HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+ HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+ HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+ HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV,
+ HWMON_F_INPUT | HWMON_F_DIV, HWMON_F_INPUT | HWMON_F_DIV),
+ NULL
+};
+
+static const struct hwmon_chip_info aspeed_tach_chip_info = {
+ .ops = &aspeed_tach_ops,
+ .info = aspeed_tach_info,
+};
+
+static void aspeed_present_fan_tach(struct aspeed_pwm_tach_data *priv, u8 *tach_ch, int count)
+{
+ u8 ch, index;
+ u32 val;
+
+ for (index = 0; index < count; index++) {
+ ch = tach_ch[index];
+ priv->tach_present[ch] = true;
+ priv->tach_divisor = DEFAULT_TACH_DIV;
+
+ val = readl(priv->base + TACH_ASPEED_CTRL(ch));
+ val &= ~(TACH_ASPEED_INVERS_LIMIT | TACH_ASPEED_DEBOUNCE_MASK |
+ TACH_ASPEED_IO_EDGE_MASK | TACH_ASPEED_CLK_DIV_T_MASK |
+ TACH_ASPEED_THRESHOLD_MASK);
+ val |= (DEBOUNCE_3_CLK << TACH_ASPEED_DEBOUNCE_BIT) |
+ F2F_EDGES |
+ FIELD_PREP(TACH_ASPEED_CLK_DIV_T_MASK,
+ DIV_TO_REG(priv->tach_divisor));
+ writel(val, priv->base + TACH_ASPEED_CTRL(ch));
+
+ aspeed_tach_ch_enable(priv, ch, true);
+ }
+}
+
+static int aspeed_tach_create_fan(struct device *dev, struct device_node *child,
+ struct aspeed_pwm_tach_data *priv)
+{
+ int ret, count;
+ u8 *tach_ch;
+
+ count = of_property_count_u8_elems(child, "tach-ch");
+ if (count < 1)
+ return -EINVAL;
+ tach_ch = devm_kcalloc(dev, count, sizeof(*tach_ch), GFP_KERNEL);
+ if (!tach_ch)
+ return -ENOMEM;
+ ret = of_property_read_u8_array(child, "tach-ch", tach_ch, count);
+ if (ret)
+ return ret;
+
+ aspeed_present_fan_tach(priv, tach_ch, count);
+
+ return 0;
+}
+
+static int aspeed_pwm_tach_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev, *hwmon;
+ int ret;
+ struct device_node *child;
+ struct aspeed_pwm_tach_data *priv;
+
+ priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+ priv->dev = dev;
+ priv->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(priv->base))
+ return PTR_ERR(priv->base);
+
+ priv->clk = devm_clk_get_enabled(dev, NULL);
+ if (IS_ERR(priv->clk))
+ return dev_err_probe(dev, PTR_ERR(priv->clk),
+ "Couldn't get clock\n");
+ priv->clk_rate = clk_get_rate(priv->clk);
+ priv->reset = devm_reset_control_get_exclusive(dev, NULL);
+ if (IS_ERR(priv->reset))
+ return dev_err_probe(dev, PTR_ERR(priv->reset),
+ "Couldn't get reset control\n");
+
+ ret = reset_control_deassert(priv->reset);
+ if (ret)
+ return dev_err_probe(dev, ret,
+ "Couldn't deassert reset control\n");
+
+ priv->chip.dev = dev;
+ priv->chip.ops = &aspeed_pwm_ops;
+ priv->chip.npwm = PWM_ASPEED_NR_PWMS;
+
+ ret = devm_pwmchip_add(dev, &priv->chip);
+ if (ret < 0) {
+ reset_control_assert(priv->reset);
+ return dev_err_probe(dev, ret, "Failed to add PWM chip\n");
+ }
+
+ for_each_child_of_node(dev->of_node, child) {
+ ret = aspeed_tach_create_fan(dev, child, priv);
+ if (ret < 0) {
+ of_node_put(child);
+ dev_warn(dev, "Failed to create fan %d", ret);
+ return 0;
+ }
+ }
+
+ hwmon = devm_hwmon_device_register_with_info(dev, "aspeed_tach", priv,
+ &aspeed_tach_chip_info, NULL);
+ ret = PTR_ERR_OR_ZERO(hwmon);
+ if (ret) {
+ reset_control_assert(priv->reset);
+ return dev_err_probe(dev, ret,
+ "Failed to register hwmon device\n");
+ }
+
+ return 0;
+}
+
+static int aspeed_pwm_tach_remove(struct platform_device *pdev)
+{
+ struct aspeed_pwm_tach_data *priv = platform_get_drvdata(pdev);
+
+ reset_control_assert(priv->reset);
+
+ return 0;
+}
+
+static const struct of_device_id aspeed_pwm_tach_match[] = {
+ {
+ .compatible = "aspeed,ast2600-pwm-tach",
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, aspeed_pwm_tach_match);
+
+static struct platform_driver aspeed_pwm_tach_driver = {
+ .probe = aspeed_pwm_tach_probe,
+ .remove = aspeed_pwm_tach_remove,
+ .driver = {
+ .name = "aspeed-g6-pwm-tach",
+ .of_match_table = aspeed_pwm_tach_match,
+ },
+};
+
+module_platform_driver(aspeed_pwm_tach_driver);
+
+MODULE_AUTHOR("Billy Tsai <billy_tsai@aspeedtech.com>");
+MODULE_DESCRIPTION("Aspeed ast2600 PWM and Fan Tach device driver");
+MODULE_LICENSE("GPL");
--
2.25.1