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Diffstat (limited to 'drivers/hwmon/aspeed-g6-pwm-tach.c')
-rw-r--r--drivers/hwmon/aspeed-g6-pwm-tach.c549
1 files changed, 549 insertions, 0 deletions
diff --git a/drivers/hwmon/aspeed-g6-pwm-tach.c b/drivers/hwmon/aspeed-g6-pwm-tach.c
new file mode 100644
index 0000000000..597b3b019d
--- /dev/null
+++ b/drivers/hwmon/aspeed-g6-pwm-tach.c
@@ -0,0 +1,549 @@
+// 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/of_platform.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_create_fan_monitor(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 void aspeed_pwm_tach_reset_assert(void *data)
+{
+ struct reset_control *rst = data;
+
+ reset_control_assert(rst);
+}
+
+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");
+ ret = devm_add_action_or_reset(dev, aspeed_pwm_tach_reset_assert,
+ priv->reset);
+ if (ret)
+ return ret;
+
+ 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)
+ return dev_err_probe(dev, ret, "Failed to add PWM chip\n");
+
+ for_each_child_of_node(dev->of_node, child) {
+ ret = aspeed_create_fan_monitor(dev, child, priv);
+ if (ret) {
+ 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)
+ return dev_err_probe(dev, ret,
+ "Failed to register hwmon device\n");
+
+ of_platform_populate(dev->of_node, NULL, NULL, dev);
+
+ 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");