[PATCH v2 3/3] hwmon: (max6639) Change from pdata to dt configuration

From: Naresh Solanki
Date: Tue Oct 11 2022 - 06:48:09 EST

From: Marcello Sylvester Bauer <sylv@xxxxxxx>

max6639_platform_data is not used by any in-kernel driver and does not
address the MAX6639 channels separately. Move to device tree
configuration with explicit properties to configure each channel.

Non-DT platform can still use this module with its default
configuration.

Signed-off-by: Marcello Sylvester Bauer <sylv@xxxxxxx>
Signed-off-by: Naresh Solanki <Naresh.Solanki@xxxxxxxxxxxxx>
---
drivers/hwmon/max6639.c | 260 +++++++++++++++++++-------
include/linux/platform_data/max6639.h | 15 --
2 files changed, 197 insertions(+), 78 deletions(-)
delete mode 100644 include/linux/platform_data/max6639.h

diff --git a/drivers/hwmon/max6639.c b/drivers/hwmon/max6639.c
index 9b895402c80d..75eb4522fc9b 100644
--- a/drivers/hwmon/max6639.c
+++ b/drivers/hwmon/max6639.c
@@ -19,48 +19,53 @@
#include <linux/hwmon-sysfs.h>
#include <linux/err.h>
#include <linux/mutex.h>
-#include <linux/platform_data/max6639.h>

/* Addresses to scan */
static const unsigned short normal_i2c[] = { 0x2c, 0x2e, 0x2f, I2C_CLIENT_END };

/* The MAX6639 registers, valid channel numbers: 0, 1 */
#define MAX6639_REG_TEMP(ch) (0x00 + (ch))
-#define MAX6639_REG_STATUS 0x02
+#define MAX6639_REG_STATUS 0x02
#define MAX6639_REG_OUTPUT_MASK 0x03
-#define MAX6639_REG_GCONFIG 0x04
+#define MAX6639_REG_GCONFIG 0x04
#define MAX6639_REG_TEMP_EXT(ch) (0x05 + (ch))
#define MAX6639_REG_ALERT_LIMIT(ch) (0x08 + (ch))
#define MAX6639_REG_OT_LIMIT(ch) (0x0A + (ch))
#define MAX6639_REG_THERM_LIMIT(ch) (0x0C + (ch))
#define MAX6639_REG_FAN_CONFIG1(ch) (0x10 + (ch) * 4)
-#define MAX6639_REG_FAN_CONFIG2a(ch) (0x11 + (ch) * 4)
-#define MAX6639_REG_FAN_CONFIG2b(ch) (0x12 + (ch) * 4)
+#define MAX6639_REG_FAN_CONFIG2a(ch) (0x11 + (ch) * 4)
+#define MAX6639_REG_FAN_CONFIG2b(ch) (0x12 + (ch) * 4)
#define MAX6639_REG_FAN_CONFIG3(ch) (0x13 + (ch) * 4)
#define MAX6639_REG_FAN_CNT(ch) (0x20 + (ch))
#define MAX6639_REG_TARGET_CNT(ch) (0x22 + (ch))
#define MAX6639_REG_FAN_PPR(ch) (0x24 + (ch))
#define MAX6639_REG_TARGTDUTY(ch) (0x26 + (ch))
-#define MAX6639_REG_FAN_START_TEMP(ch) (0x28 + (ch))
-#define MAX6639_REG_DEVID 0x3D
-#define MAX6639_REG_MANUID 0x3E
-#define MAX6639_REG_DEVREV 0x3F
+#define MAX6639_REG_FAN_START_TEMP(ch) (0x28 + (ch))
+#define MAX6639_REG_DEVID 0x3D
+#define MAX6639_REG_MANUID 0x3E
+#define MAX6639_REG_DEVREV 0x3F

/* Register bits */
+#define MAX6639_REG_OUTPUT_MASK_OT(x, ch) (x << (5 - ch))
+#define MAX6639_REG_OUTPUT_MASK_THERM(x, ch) (x << (3 - ch))
+#define MAX6639_REG_OUTPUT_MASK_FANFAIL(x, ch) (x << (1 - ch))
#define MAX6639_GCONFIG_STANDBY 0x80
-#define MAX6639_GCONFIG_POR 0x40
-#define MAX6639_GCONFIG_DISABLE_TIMEOUT 0x20
+#define MAX6639_GCONFIG_POR 0x40
+#define MAX6639_GCONFIG_DISABLE_TIMEOUT 0x20
#define MAX6639_GCONFIG_CH2_LOCAL 0x10
#define MAX6639_GCONFIG_PWM_FREQ_HI 0x08

#define MAX6639_FAN_CONFIG1_PWM 0x80

+#define MAX6639_FAN_CONFIG3_THERM_FULL_SPEED 0x40
+#define MAX6639_FAN_CONFIG3_SPIN_UP_DISABLE 0x80
#define MAX6639_FAN_CONFIG3_THERM_FULL_SPEED 0x40

static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };

#define FAN_FROM_REG(val, rpm_range) ((val) == 0 || (val) == 255 ? \
0 : (rpm_ranges[rpm_range] * 30) / (val))
+
#define TEMP_LIMIT_TO_REG(val) clamp_val((val) / 1000, 0, 255)

/*
@@ -69,7 +74,7 @@ static const int rpm_ranges[] = { 2000, 4000, 8000, 16000 };
struct max6639_data {
struct i2c_client *client;
struct mutex update_lock;
- bool valid; /* true if following fields are valid */
+ char valid; /* !=0 if following fields are valid */
unsigned long last_updated; /* In jiffies */

/* Register values sampled regularly */
@@ -85,9 +90,14 @@ struct max6639_data {
u8 temp_ot[2]; /* OT Temperature, 0..255 C (->_emergency) */

/* Register values initialized only once */
- u8 ppr; /* Pulses per rotation 0..3 for 1..4 ppr */
- u8 rpm_range; /* Index in above rpm_ranges table */
-
+ u8 ppr[2]; /* Pulses per rotation 0..3 for 1..4 ppr */
+ u8 rpm_range[2]; /* Index in above rpm_ranges table */
+ u8 pwm_polarity[2]; /* Fans PWM polarity, 0..1 */
+ bool full_speed_on_therm[2]; /* disable THERM full speed assertion */
+ bool spin_up_enable[2]; /* Enable fan spin-up if fan is not spinning */
+ bool ot_indication[2]; /* Enable OT pin indication */
+ bool therm_indication[2]; /* Enable THERM pin indication */
+ bool fan_fail_indication[2]; /* Enable FANFAIL pin indication */
/* Optional regulator for FAN supply */
struct regulator *reg;
};
@@ -144,7 +154,7 @@ static struct max6639_data *max6639_update_device(struct device *dev)
}

data->last_updated = jiffies;
- data->valid = true;
+ data->valid = 1;
}
abort:
mutex_unlock(&data->update_lock);
@@ -319,7 +329,7 @@ static ssize_t fan_input_show(struct device *dev,
return PTR_ERR(data);

return sprintf(buf, "%d\n", FAN_FROM_REG(data->fan[attr->index],
- data->rpm_range));
+ data->rpm_range[attr->index]));
}

static ssize_t alarm_show(struct device *dev,
@@ -386,28 +396,34 @@ static struct attribute *max6639_attrs[] = {
ATTRIBUTE_GROUPS(max6639);

/*
- * returns respective index in rpm_ranges table
- * 1 by default on invalid range
+ * Get respective index in rpm_ranges table
*/
-static int rpm_range_to_reg(int range)
+static int rpm_range_to_index(u8 *index, int rpm)
{
int i;

+ if (rpm <= 0)
+ return -EINVAL;
+
+ /* If provided RPM is more than 16000 RPM then select 16000
+ * RPM range.
+ */
+ *index = ARRAY_SIZE(rpm_ranges) - 1;
+
for (i = 0; i < ARRAY_SIZE(rpm_ranges); i++) {
- if (rpm_ranges[i] == range)
- return i;
+ if (rpm <= rpm_ranges[i]) {
+ *index = i;
+ break;
+ }
}

- return 1; /* default: 4000 RPM */
+ return 0;
}

static int max6639_init_client(struct i2c_client *client,
struct max6639_data *data)
{
- struct max6639_platform_data *max6639_info =
- dev_get_platdata(&client->dev);
- int i;
- int rpm_range = 1; /* default: 4000 RPM */
+ int i, val;
int err;

/* Reset chip to default values, see below for GCONFIG setup */
@@ -416,58 +432,40 @@ static int max6639_init_client(struct i2c_client *client,
if (err)
goto exit;

- /* Fans pulse per revolution is 2 by default */
- if (max6639_info && max6639_info->ppr > 0 &&
- max6639_info->ppr < 5)
- data->ppr = max6639_info->ppr;
- else
- data->ppr = 2;
- data->ppr -= 1;
-
- if (max6639_info)
- rpm_range = rpm_range_to_reg(max6639_info->rpm_range);
- data->rpm_range = rpm_range;
-
for (i = 0; i < 2; i++) {

/* Set Fan pulse per revolution */
err = i2c_smbus_write_byte_data(client,
MAX6639_REG_FAN_PPR(i),
- data->ppr << 6);
+ data->ppr[i] << 6);
if (err)
goto exit;

/* Fans config PWM, RPM */
err = i2c_smbus_write_byte_data(client,
MAX6639_REG_FAN_CONFIG1(i),
- MAX6639_FAN_CONFIG1_PWM | rpm_range);
+ MAX6639_FAN_CONFIG1_PWM | data->rpm_range[i]);
if (err)
goto exit;

- /* Fans PWM polarity high by default */
- if (max6639_info && max6639_info->pwm_polarity == 0)
- err = i2c_smbus_write_byte_data(client,
- MAX6639_REG_FAN_CONFIG2a(i), 0x00);
- else
- err = i2c_smbus_write_byte_data(client,
- MAX6639_REG_FAN_CONFIG2a(i), 0x02);
- if (err)
- goto exit;
+ /* Fans PWM polarity */
+ err = i2c_smbus_write_byte_data(client,
+ MAX6639_REG_FAN_CONFIG2a(i), data->pwm_polarity[i] ? 0x02 : 0x00);

/*
- * /THERM full speed enable,
+ * Full speed on therm, spin-up at zero rpm.
* PWM frequency 25kHz, see also GCONFIG below
*/
err = i2c_smbus_write_byte_data(client,
MAX6639_REG_FAN_CONFIG3(i),
- MAX6639_FAN_CONFIG3_THERM_FULL_SPEED | 0x03);
+ (data->full_speed_on_therm[i] ?
+ MAX6639_FAN_CONFIG3_THERM_FULL_SPEED : 0) |
+ (data->spin_up_enable[i] ?
+ 0 : MAX6639_FAN_CONFIG3_SPIN_UP_DISABLE) | 0x03);
+
if (err)
goto exit;

- /* Max. temp. 80C/90C/100C */
- data->temp_therm[i] = 80;
- data->temp_alert[i] = 90;
- data->temp_ot[i] = 100;
err = i2c_smbus_write_byte_data(client,
MAX6639_REG_THERM_LIMIT(i),
data->temp_therm[i]);
@@ -483,13 +481,24 @@ static int max6639_init_client(struct i2c_client *client,
if (err)
goto exit;

- /* PWM 120/120 (i.e. 100%) */
- data->pwm[i] = 120;
err = i2c_smbus_write_byte_data(client,
MAX6639_REG_TARGTDUTY(i), data->pwm[i]);
if (err)
goto exit;
}
+
+ val = 0;
+ for (i = 0; i < 2; i++) {
+ val |= MAX6639_REG_OUTPUT_MASK_OT(
+ data->ot_indication[i], i);
+ val |= MAX6639_REG_OUTPUT_MASK_THERM(
+ data->therm_indication[i], i);
+ val |= MAX6639_REG_OUTPUT_MASK_FANFAIL(
+ data->fan_fail_indication[i], i);
+ }
+ /* Configure output mask register */
+ err = i2c_smbus_write_byte_data(client, MAX6639_REG_OUTPUT_MASK, val);
+
/* Start monitoring */
err = i2c_smbus_write_byte_data(client, MAX6639_REG_GCONFIG,
MAX6639_GCONFIG_DISABLE_TIMEOUT | MAX6639_GCONFIG_CH2_LOCAL |
@@ -524,12 +533,105 @@ static void max6639_regulator_disable(void *data)
regulator_disable(data);
}

+static int max6639_probe_child_from_dt(struct i2c_client *client,
+ struct device_node *child,
+ struct max6639_data *data)
+
+{
+ struct device *dev = &client->dev;
+ u32 i, val, maxrpm;
+ int err;
+
+ err = of_property_read_u32(child, "reg", &i);
+ if (err) {
+ dev_err(dev, "missing reg property of %pOFn\n", child);
+ return err;
+ }
+
+ if (i >= 2) {
+ dev_err(dev, "invalid reg %d of %pOFn\n", i, child);
+ return -EINVAL;
+ }
+
+ err = of_property_read_u32(child, "pulses-per-revolution", &val);
+ if (err) {
+ dev_err(dev, "missing pulses-per-revolution property of %pOFn\n", child);
+ return err;
+ }
+
+ if (val < 0 || val > 5) {
+ dev_err(dev, "invalid pulses-per-revolution %d of %pOFn\n", val, child);
+ return -EINVAL;
+ }
+ data->ppr[i] = val;
+
+ err = of_property_read_u32(child, "max-rpm", &maxrpm);
+ if (err) {
+ dev_err(dev, "missing max-rpm property of %pOFn\n", child);
+ return err;
+ }
+
+ err = rpm_range_to_index(&data->rpm_range[i], maxrpm);
+ if (err) {
+ dev_err(dev, "invalid max-rpm %d of %pOFn\n", maxrpm, child);
+ return err;
+ }
+
+
+ err = of_property_read_u32(child, "target-rpm", &val);
+ /* Convert to PWM from provided target RPM */
+ if (!err && val != 0)
+ data->pwm[i] =
+ (u8)(val * 255 / maxrpm);
+
+ data->pwm_polarity[i] = of_property_read_bool(child, "pwm-polarity-inverse");
+
+ data->spin_up_enable[i] = of_property_read_bool(child, "maxim,fan-spin-up");
+
+ data->full_speed_on_therm[i] = of_property_read_bool(child,
+ "maxim,full-speed-on-therm");
+
+ data->fan_fail_indication[i] = of_property_read_bool(child, "maxim,fanfail_indication");
+
+ return 0;
+}
+
+static int max6639_probe_from_dt(struct i2c_client *client, struct max6639_data *data)
+{
+ struct device *dev = &client->dev;
+ const struct device_node *np = dev->of_node;
+ struct device_node *child;
+ int err;
+
+ /* Compatible with non-DT platforms */
+ if (!np)
+ return 0;
+
+ for_each_child_of_node(np, child) {
+ if (strcmp(child->name, "fan"))
+ continue;
+
+ err = max6639_probe_child_from_dt(client, child, data);
+ if (err) {
+ of_node_put(child);
+ return err;
+ }
+ }
+
+ data->ot_indication[0] = !of_property_read_bool(np, "ot0_indication");
+ data->ot_indication[1] = !of_property_read_bool(np, "ot1_indication");
+ data->therm_indication[0] = !of_property_read_bool(np, "therm0_indication");
+ data->therm_indication[1] = !of_property_read_bool(np, "therm1_indication");
+
+ return 0;
+}
+
static int max6639_probe(struct i2c_client *client)
{
struct device *dev = &client->dev;
struct max6639_data *data;
struct device *hwmon_dev;
- int err;
+ int err, i;

data = devm_kzalloc(dev, sizeof(struct max6639_data), GFP_KERNEL);
if (!data)
@@ -539,9 +641,11 @@ static int max6639_probe(struct i2c_client *client)

data->reg = devm_regulator_get_optional(dev, "fan");
if (IS_ERR(data->reg)) {
- if (PTR_ERR(data->reg) != -ENODEV)
- return PTR_ERR(data->reg);
-
+ if (PTR_ERR(data->reg) != -ENODEV) {
+ err = (int)PTR_ERR(data->reg);
+ dev_warn(dev, "Failed looking up fan supply: %d\n", err);
+ return err;
+ }
data->reg = NULL;
} else {
/* Spin up fans */
@@ -560,6 +664,25 @@ static int max6639_probe(struct i2c_client *client)

mutex_init(&data->update_lock);

+ /* default values */
+ for (i = 0; i < 2; i++) {
+ /* 4000 RPM */
+ data->rpm_range[i] = 1;
+ data->ppr[i] = 2;
+ data->pwm_polarity[i] = 1;
+ /* Max. temp. 80C/90C/100C */
+ data->temp_therm[i] = 80;
+ data->temp_alert[i] = 90;
+ data->temp_ot[i] = 100;
+ /* PWM 120/120 (i.e. 100%) */
+ data->pwm[i] = 120;
+ data->full_speed_on_therm[i] = false;
+ }
+
+ err = max6639_probe_from_dt(client, data);
+ if (err)
+ return err;
+
/* Initialize the max6639 chip */
err = max6639_init_client(client, data);
if (err < 0)
@@ -571,6 +694,7 @@ static int max6639_probe(struct i2c_client *client)
return PTR_ERR_OR_ZERO(hwmon_dev);
}

+#if IS_ENABLED(CONFIG_PM_SLEEP)
static int max6639_suspend(struct device *dev)
{
struct i2c_client *client = to_i2c_client(dev);
@@ -608,6 +732,7 @@ static int max6639_resume(struct device *dev)
return i2c_smbus_write_byte_data(client,
MAX6639_REG_GCONFIG, ret & ~MAX6639_GCONFIG_STANDBY);
}
+#endif

static const struct i2c_device_id max6639_id[] = {
{"max6639", 0},
@@ -616,13 +741,22 @@ static const struct i2c_device_id max6639_id[] = {

MODULE_DEVICE_TABLE(i2c, max6639_id);

-static DEFINE_SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);
+#ifdef CONFIG_OF
+static const struct of_device_id maxim_of_platform_match[] = {
+ {.compatible = "maxim,max6639"},
+ {},
+};
+MODULE_DEVICE_TABLE(of, maxim_of_platform_match);
+#endif
+
+static SIMPLE_DEV_PM_OPS(max6639_pm_ops, max6639_suspend, max6639_resume);

static struct i2c_driver max6639_driver = {
.class = I2C_CLASS_HWMON,
.driver = {
.name = "max6639",
.pm = pm_sleep_ptr(&max6639_pm_ops),
+ .of_match_table = of_match_ptr(maxim_of_platform_match),
},
.probe_new = max6639_probe,
.id_table = max6639_id,
diff --git a/include/linux/platform_data/max6639.h b/include/linux/platform_data/max6639.h
deleted file mode 100644
index 65bfdb4fdc15..000000000000
--- a/include/linux/platform_data/max6639.h
+++ /dev/null
@@ -1,15 +0,0 @@
-/* SPDX-License-Identifier: GPL-2.0 */
-#ifndef _LINUX_MAX6639_H
-#define _LINUX_MAX6639_H
-
-#include <linux/types.h>
-
-/* platform data for the MAX6639 temperature sensor and fan control */
-
-struct max6639_platform_data {
- bool pwm_polarity; /* Polarity low (0) or high (1, default) */
- int ppr; /* Pulses per rotation 1..4 (default == 2) */
- int rpm_range; /* 2000, 4000 (default), 8000 or 16000 */
-};
-
-#endif /* _LINUX_MAX6639_H */
--
2.37.3