[PATCH v4 3/3] hwmon: Driver for Nuvoton NCT7363Y
Zev Weiss
zev at bewilderbeest.net
Sat Mar 2 19:18:57 AEDT 2024
On Mon, Feb 26, 2024 at 04:56:06PM PST, baneric926 at gmail.com wrote:
>From: Ban Feng <kcfeng0 at nuvoton.com>
>
>NCT7363Y is an I2C based hardware monitoring chip from Nuvoton.
>
>Signed-off-by: Ban Feng <kcfeng0 at nuvoton.com>
>---
> Documentation/hwmon/index.rst | 1 +
> Documentation/hwmon/nct7363.rst | 33 +++
> MAINTAINERS | 2 +
> drivers/hwmon/Kconfig | 11 +
> drivers/hwmon/Makefile | 1 +
> drivers/hwmon/nct7363.c | 412 ++++++++++++++++++++++++++++++++
> 6 files changed, 460 insertions(+)
> create mode 100644 Documentation/hwmon/nct7363.rst
> create mode 100644 drivers/hwmon/nct7363.c
>
>diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
>index c7ed1f73ac06..302f954b45be 100644
>--- a/Documentation/hwmon/index.rst
>+++ b/Documentation/hwmon/index.rst
>@@ -165,6 +165,7 @@ Hardware Monitoring Kernel Drivers
> mp5990
> nct6683
> nct6775
>+ nct7363
> nct7802
> nct7904
> npcm750-pwm-fan
>diff --git a/Documentation/hwmon/nct7363.rst b/Documentation/hwmon/nct7363.rst
>new file mode 100644
>index 000000000000..89699c95aa4b
>--- /dev/null
>+++ b/Documentation/hwmon/nct7363.rst
>@@ -0,0 +1,33 @@
>+.. SPDX-License-Identifier: GPL-2.0
>+
>+Kernel driver nct7363
>+=====================
>+
>+Supported chip:
>+
>+ * Nuvoton NCT7363Y
>+
>+ Prefix: nct7363
>+
>+ Addresses: I2C 0x20, 0x21, 0x22, 0x23
>+
>+Author: Ban Feng <kcfeng0 at nuvoton.com>
>+
>+
>+Description
>+-----------
>+
>+The NCT7363Y is a Fan controller which provides up to 16 independent
>+FAN input monitors, and up to 16 independent PWM output with SMBus interface.
>+
>+
>+Sysfs entries
>+-------------
>+
>+Currently, the driver supports the following features:
>+
>+======================= =======================================================
>+fanX_input provide current fan rotation value in RPM
>+
>+pwmX get or set PWM fan control value.
>+======================= =======================================================
>diff --git a/MAINTAINERS b/MAINTAINERS
>index 7b1efefed7c4..7ca66b713e30 100644
>--- a/MAINTAINERS
>+++ b/MAINTAINERS
>@@ -15089,6 +15089,8 @@ M: Ban Feng <kcfeng0 at nuvoton.com>
> L: linux-hwmon at vger.kernel.org
> S: Maintained
> F: Documentation/devicetree/bindings/hwmon/nuvoton,nct7363.yaml
>+F: Documentation/hwmon/nct7363.rst
>+F: drivers/hwmon/nct7363.c
>
> NETDEVSIM
> M: Jakub Kicinski <kuba at kernel.org>
>diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
>index a608264da87d..a297b5409b04 100644
>--- a/drivers/hwmon/Kconfig
>+++ b/drivers/hwmon/Kconfig
>@@ -1616,6 +1616,17 @@ config SENSORS_NCT6775_I2C
> This driver can also be built as a module. If so, the module
> will be called nct6775-i2c.
>
>+config SENSORS_NCT7363
>+ tristate "Nuvoton NCT7363Y"
>+ depends on I2C
>+ select REGMAP_I2C
>+ help
>+ If you say yes here you get support for the Nuvoton NCT7363Y,
>+ hardware monitoring chip.
>+
>+ This driver can also be built as a module. If so, the module
>+ will be called nct7363.
>+
> config SENSORS_NCT7802
> tristate "Nuvoton NCT7802Y"
> depends on I2C
>diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
>index 47be39af5c03..d5e7531204df 100644
>--- a/drivers/hwmon/Makefile
>+++ b/drivers/hwmon/Makefile
>@@ -167,6 +167,7 @@ obj-$(CONFIG_SENSORS_NCT6775_CORE) += nct6775-core.o
> nct6775-objs := nct6775-platform.o
> obj-$(CONFIG_SENSORS_NCT6775) += nct6775.o
> obj-$(CONFIG_SENSORS_NCT6775_I2C) += nct6775-i2c.o
>+obj-$(CONFIG_SENSORS_NCT7363) += nct7363.o
> obj-$(CONFIG_SENSORS_NCT7802) += nct7802.o
> obj-$(CONFIG_SENSORS_NCT7904) += nct7904.o
> obj-$(CONFIG_SENSORS_NPCM7XX) += npcm750-pwm-fan.o
>diff --git a/drivers/hwmon/nct7363.c b/drivers/hwmon/nct7363.c
>new file mode 100644
>index 000000000000..c79d3ca4f111
>--- /dev/null
>+++ b/drivers/hwmon/nct7363.c
>@@ -0,0 +1,412 @@
>+// SPDX-License-Identifier: GPL-2.0-or-later
>+/*
>+ * Copyright (c) 2023 Nuvoton Technology corporation.
>+ */
>+
>+#include <linux/bitfield.h>
>+#include <linux/bits.h>
>+#include <linux/err.h>
>+#include <linux/hwmon.h>
>+#include <linux/hwmon-sysfs.h>
>+#include <linux/i2c.h>
>+#include <linux/module.h>
>+#include <linux/mutex.h>
>+#include <linux/regmap.h>
>+#include <linux/slab.h>
>+
>+#define NCT7363_REG_GPIO_0_3 0x20
>+#define NCT7363_REG_GPIO_4_7 0x21
>+#define NCT7363_REG_GPIO_10_13 0x22
>+#define NCT7363_REG_GPIO_14_17 0x23
>+#define NCT7363_REG_PWMEN_0_7 0x38
>+#define NCT7363_REG_PWMEN_8_15 0x39
>+#define NCT7363_REG_FANINEN_0_7 0x41
>+#define NCT7363_REG_FANINEN_8_15 0x42
>+#define NCT7363_REG_FANINX_HVAL(x) (0x48 + ((x) * 2))
>+#define NCT7363_REG_FANINX_LVAL(x) (0x49 + ((x) * 2))
>+#define NCT7363_REG_FSCPXDUTY(x) (0x90 + ((x) * 2))
>+
>+#define PWM_SEL(x) (BIT(0) << (((x) % 4) * 2))
>+#define FANIN_SEL(x) (BIT(1) << (((x) % 4) * 2))
>+
>+#define NCT7363_FANINX_LVAL_MASK GENMASK(4, 0)
>+#define NCT7363_FANIN_MASK GENMASK(12, 0)
>+
>+#define NCT7363_PWM_COUNT 16
>+
>+static inline unsigned long FAN_FROM_REG(u16 val)
>+{
>+ /* In case fan is stopped or divide by 0 */
>+ if (val == NCT7363_FANIN_MASK || val == 0)
>+ return 0;
>+
>+ return (1350000UL / val);
>+}
>+
>+static const struct of_device_id nct7363_of_match[] = {
>+ { .compatible = "nuvoton,nct7363" },
As far as I can see from the code in this driver, it looks like this
driver should also be compatible with the nct7362; shall we add the ID
table entry for it now? (Though I only have a datasheet for the
nct7362, not the nct7363, so I don't know exactly how they differ.)
>+ { },
>+};
>+MODULE_DEVICE_TABLE(of, nct7363_of_match);
>+
>+struct nct7363_data {
>+ struct regmap *regmap;
>+ struct mutex lock; /* protect register access */
>+
>+ u16 fanin_mask;
>+ u16 pwm_mask;
>+};
>+
>+static int nct7363_read_fan(struct device *dev, u32 attr, int channel,
>+ long *val)
>+{
>+ struct nct7363_data *data = dev_get_drvdata(dev);
>+ unsigned int hi, lo;
>+ u16 cnt, rpm;
>+ int ret = 0;
>+
>+ switch (attr) {
>+ case hwmon_fan_input:
>+ /*
>+ * High-byte register should be read first to latch
>+ * synchronous low-byte value
>+ */
>+ ret = regmap_read(data->regmap,
>+ NCT7363_REG_FANINX_HVAL(channel), &hi);
>+ if (ret)
>+ return ret;
>+
>+ ret = regmap_read(data->regmap,
>+ NCT7363_REG_FANINX_LVAL(channel), &lo);
>+ if (ret)
>+ return ret;
I think this pair of reads should be done under data->lock to ensure
that the LVAL read gets the right latched value in a scenario where
multiple threads executing this function end up with their register
reads interleaved.
>+
>+ cnt = (hi << 5) | (lo & NCT7363_FANINX_LVAL_MASK);
>+ rpm = FAN_FROM_REG(cnt);
>+ *val = (long)rpm;
Given that rpm is assigned from an unsigned long (FAN_FROM_REG()) and
then to a long (*val), is there any reason we want it as a u16 in
between the two? Or for that matter, why not just:
*val = FAN_FROM_REG(cnt);
?
>+ return 0;
>+ default:
>+ return -EOPNOTSUPP;
>+ }
>+}
>+
>+static umode_t nct7363_fan_is_visible(const void *_data, u32 attr, int channel)
>+{
>+ const struct nct7363_data *data = _data;
>+
>+ switch (attr) {
>+ case hwmon_fan_input:
>+ if (data->fanin_mask & BIT(channel))
>+ return 0444;
>+ break;
>+ default:
>+ break;
>+ }
>+
>+ return 0;
>+}
>+
>+static int nct7363_read_pwm(struct device *dev, u32 attr, int channel,
>+ long *val)
>+{
>+ struct nct7363_data *data = dev_get_drvdata(dev);
>+ unsigned int regval;
>+ u16 ret;
>+
>+ switch (attr) {
>+ case hwmon_pwm_input:
>+ ret = regmap_read(data->regmap,
>+ NCT7363_REG_FSCPXDUTY(channel), ®val);
>+ if (ret)
>+ return ret;
>+
>+ *val = (long)regval;
>+ return 0;
>+ default:
>+ return -EOPNOTSUPP;
>+ }
>+}
>+
>+static int nct7363_write_pwm(struct device *dev, u32 attr, int channel,
>+ long val)
>+{
>+ struct nct7363_data *data = dev_get_drvdata(dev);
>+ int ret;
>+
>+ switch (attr) {
>+ case hwmon_pwm_input:
>+ if (val < 0 || val > 255)
>+ return -EINVAL;
>+
>+ mutex_lock(&data->lock);
>+ ret = regmap_write(data->regmap,
>+ NCT7363_REG_FSCPXDUTY(channel), val);
>+ mutex_unlock(&data->lock);
...though here, I'm not sure the locking is needed -- is there something
that necessitates it for a single register write?
>+
>+ return ret;
>+
>+ default:
>+ return -EOPNOTSUPP;
>+ }
>+}
>+
>+static umode_t nct7363_pwm_is_visible(const void *_data, u32 attr, int channel)
>+{
>+ const struct nct7363_data *data = _data;
>+
>+ switch (attr) {
>+ case hwmon_pwm_input:
>+ if (data->pwm_mask & BIT(channel))
>+ return 0644;
>+ break;
>+ default:
>+ break;
>+ }
>+
>+ return 0;
>+}
>+
>+static int nct7363_read(struct device *dev, enum hwmon_sensor_types type,
>+ u32 attr, int channel, long *val)
>+{
>+ switch (type) {
>+ case hwmon_fan:
>+ return nct7363_read_fan(dev, attr, channel, val);
>+ case hwmon_pwm:
>+ return nct7363_read_pwm(dev, attr, channel, val);
>+ default:
>+ return -EOPNOTSUPP;
>+ }
>+}
>+
>+static int nct7363_write(struct device *dev, enum hwmon_sensor_types type,
>+ u32 attr, int channel, long val)
>+{
>+ switch (type) {
>+ case hwmon_pwm:
>+ return nct7363_write_pwm(dev, attr, channel, val);
>+ default:
>+ return -EOPNOTSUPP;
>+ }
>+}
>+
>+static umode_t nct7363_is_visible(const void *data,
>+ enum hwmon_sensor_types type,
>+ u32 attr, int channel)
>+{
>+ switch (type) {
>+ case hwmon_fan:
>+ return nct7363_fan_is_visible(data, attr, channel);
>+ case hwmon_pwm:
>+ return nct7363_pwm_is_visible(data, attr, channel);
>+ default:
>+ return 0;
>+ }
>+}
>+
>+static const struct hwmon_channel_info *nct7363_info[] = {
>+ 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),
>+ 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),
>+ NULL
>+};
>+
>+static const struct hwmon_ops nct7363_hwmon_ops = {
>+ .is_visible = nct7363_is_visible,
>+ .read = nct7363_read,
>+ .write = nct7363_write,
>+};
>+
>+static const struct hwmon_chip_info nct7363_chip_info = {
>+ .ops = &nct7363_hwmon_ops,
>+ .info = nct7363_info,
>+};
>+
>+static int nct7363_init_chip(struct nct7363_data *data)
>+{
>+ u8 i, gpio0_3 = 0, gpio4_7 = 0, gpio10_13 = 0, gpio14_17 = 0;
>+ int ret;
>+
>+ for (i = 0; i < NCT7363_PWM_COUNT; i++) {
>+ if (i < 4) {
>+ if (data->pwm_mask & BIT(i))
>+ gpio0_3 |= PWM_SEL(i);
>+ if (data->fanin_mask & BIT(i))
>+ gpio10_13 |= FANIN_SEL(i);
>+ } else if (i < 8) {
>+ if (data->pwm_mask & BIT(i))
>+ gpio4_7 |= PWM_SEL(i);
>+ if (data->fanin_mask & BIT(i))
>+ gpio14_17 |= FANIN_SEL(i);
>+ } else if (i < 12) {
>+ if (data->pwm_mask & BIT(i))
>+ gpio10_13 |= PWM_SEL(i);
>+ if (data->fanin_mask & BIT(i))
>+ gpio0_3 |= FANIN_SEL(i);
>+ } else {
>+ if (data->pwm_mask & BIT(i))
>+ gpio14_17 |= PWM_SEL(i);
>+ if (data->fanin_mask & BIT(i))
>+ gpio4_7 |= FANIN_SEL(i);
>+ }
>+ }
With the caveat that I haven't actually sketched it out myself to be
sure, might it be a bit cleaner to do this with a 4-element array
indexed by 'i / 4' instead of a big if/else chain and a bunch of
near-duplicated blocks?
>+
>+ /* Pin Function Configuration */
>+ ret = regmap_write(data->regmap, NCT7363_REG_GPIO_0_3, gpio0_3);
>+ if (ret < 0)
>+ return ret;
>+ ret = regmap_write(data->regmap, NCT7363_REG_GPIO_4_7, gpio4_7);
>+ if (ret < 0)
>+ return ret;
>+ ret = regmap_write(data->regmap, NCT7363_REG_GPIO_10_13, gpio10_13);
>+ if (ret < 0)
>+ return ret;
>+ ret = regmap_write(data->regmap, NCT7363_REG_GPIO_14_17, gpio14_17);
>+ if (ret < 0)
>+ return ret;
>+
>+ /* PWM and FANIN Monitoring Enable */
>+ ret = regmap_write(data->regmap, NCT7363_REG_PWMEN_0_7,
>+ data->pwm_mask & 0xff);
>+ if (ret < 0)
>+ return ret;
>+ ret = regmap_write(data->regmap, NCT7363_REG_PWMEN_8_15,
>+ (data->pwm_mask >> 8) & 0xff);
>+ if (ret < 0)
>+ return ret;
>+ ret = regmap_write(data->regmap, NCT7363_REG_FANINEN_0_7,
>+ data->fanin_mask & 0xff);
>+ if (ret < 0)
>+ return ret;
>+ ret = regmap_write(data->regmap, NCT7363_REG_FANINEN_8_15,
>+ (data->fanin_mask >> 8) & 0xff);
>+ if (ret < 0)
>+ return ret;
>+
>+ return 0;
>+}
>+
>+static int nct7363_present_pwm_fanin(struct device *dev,
>+ struct device_node *child,
>+ struct nct7363_data *data)
>+{
>+ struct of_phandle_args args;
>+ int ret, fanin_cnt;
>+ u8 *fanin_ch;
>+ u8 ch, index;
>+
>+ ret = of_parse_phandle_with_args(child, "pwms", "#pwm-cells",
>+ 0, &args);
>+ if (ret)
>+ return ret;
>+
>+ data->pwm_mask |= BIT(args.args[0]);
Perhaps we should have
if (args.args[0] >= NCT7363_PWM_COUNT)
return -EINVAL;
here?
>+
>+ fanin_cnt = of_property_count_u8_elems(child, "tach-ch");
>+ if (fanin_cnt < 1)
fanin_cnt < 1 || fanin_cnt >= NCT7363_PWM_COUNT
>+ return -EINVAL;
>+
>+ fanin_ch = devm_kcalloc(dev, fanin_cnt, sizeof(*fanin_ch), GFP_KERNEL);
Keeping this allocation around persistently for the whole lifetime of
the device seems unnecessary -- it's not used beyond this function,
right? In fact, dynamically allocating it at all seems like overkill,
considering that in addition to being temporary, it's also got a pretty
small upper bound on its size. I'd think a simple
u8 fanin_ch[NCT7363_PWM_COUNT];
would suffice? (Along with the check above to ensure fanin_cnt is
within range of course.)
>+ if (!fanin_ch)
>+ return -ENOMEM;
>+
>+ ret = of_property_read_u8_array(child, "tach-ch", fanin_ch, fanin_cnt);
>+ if (ret)
>+ return ret;
>+
>+ for (ch = 0; ch < fanin_cnt; ch++) {
>+ index = fanin_ch[ch];
...and likewise a range check here too?
>+ data->fanin_mask |= BIT(index);
>+ }
>+
Should we also grab the pulses-per-revolution property here and factor
that in in FAN_FROM_REG()?
>+ return 0;
>+}
>+
>+static const struct regmap_config nct7363_regmap_config = {
>+ .reg_bits = 8,
>+ .val_bits = 8,
>+};
>+
>+static int nct7363_probe(struct i2c_client *client)
>+{
>+ struct device *dev = &client->dev;
>+ struct device_node *child;
>+ struct nct7363_data *data;
>+ struct device *hwmon_dev;
>+ int ret;
>+
>+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
>+ if (!data)
>+ return -ENOMEM;
>+
>+ data->regmap = devm_regmap_init_i2c(client, &nct7363_regmap_config);
>+ if (IS_ERR(data->regmap))
>+ return PTR_ERR(data->regmap);
>+
>+ mutex_init(&data->lock);
>+
>+ for_each_child_of_node(dev->of_node, child) {
>+ ret = nct7363_present_pwm_fanin(dev, child, data);
>+ if (ret) {
>+ of_node_put(child);
>+ return ret;
>+ }
>+ }
>+
>+ /* Initialize the chip */
>+ ret = nct7363_init_chip(data);
>+ if (ret)
>+ return ret;
>+
>+ hwmon_dev =
>+ devm_hwmon_device_register_with_info(dev, client->name, data,
>+ &nct7363_chip_info, NULL);
>+ return PTR_ERR_OR_ZERO(hwmon_dev);
>+}
>+
>+static struct i2c_driver nct7363_driver = {
>+ .class = I2C_CLASS_HWMON,
Maybe add an i2c_device_id table to accompany the of_match table?
>+ .driver = {
>+ .name = "nct7363",
>+ .of_match_table = nct7363_of_match,
>+ },
>+ .probe = nct7363_probe,
>+};
>+
>+module_i2c_driver(nct7363_driver);
>+
>+MODULE_AUTHOR("CW Ho <cwho at nuvoton.com>");
>+MODULE_AUTHOR("Ban Feng <kcfeng0 at nuvoton.com>");
>+MODULE_DESCRIPTION("NCT7363 Hardware Monitoring Driver");
>+MODULE_LICENSE("GPL");
>--
>2.34.1
>
>
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