[PATCH v2 4/4] hwmon: (max6639) Change from pdata to dt configuration

From: Marcello Sylvester Bauer
Date: Mon Jan 17 2022 - 05:41:10 EST


max6639_platform_data is not used by any in-kernel driver and does not
address the MAX6639 channels separately. Move to a strict 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>
---
drivers/hwmon/max6639.c | 171 +++++++++++++++++++-------
include/linux/platform_data/max6639.h | 15 ---
2 files changed, 128 insertions(+), 58 deletions(-)
delete mode 100644 include/linux/platform_data/max6639.h

diff --git a/drivers/hwmon/max6639.c b/drivers/hwmon/max6639.c
index 0b241f029229..26772532bce4 100644
--- a/drivers/hwmon/max6639.c
+++ b/drivers/hwmon/max6639.c
@@ -19,7 +19,6 @@
#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 };
@@ -85,8 +84,9 @@ 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 */

/* Optional regulator for FAN supply */
struct regulator *reg;
@@ -319,7 +319,7 @@ 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 +386,26 @@ 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 range)
{
int i;

for (i = 0; i < ARRAY_SIZE(rpm_ranges); i++) {
- if (rpm_ranges[i] == range)
- return i;
+ if (rpm_ranges[i] == range) {
+ *index = i;
+ return 0;
+ }
}

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

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 err;

/* Reset chip to default values, see below for GCONFIG setup */
@@ -416,43 +414,25 @@ 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] ? 0x00 : 0x02);

/*
* /THERM full speed enable,
@@ -464,10 +444,6 @@ static int max6639_init_client(struct i2c_client *client,
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]);
@@ -483,8 +459,6 @@ 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)
@@ -524,12 +498,96 @@ 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;
+ 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, "rpm-range", &val);
+ if (err) {
+ dev_err(dev, "missing rpm-range property of %pOFn\n", child);
+ return err;
+ }
+
+ err = rpm_range_to_index(&data->rpm_range[i], val);
+ if (err) {
+ dev_err(dev, "invalid rpm-range %d of %pOFn\n", val, child);
+ return err;
+ }
+
+ err = of_property_read_u32(child, "pwm-polarity", &val);
+ if (err) {
+ dev_err(dev, "missing pwm-polarity property of %pOFn\n", child);
+ return err;
+ }
+
+ if (val > 1) {
+ dev_err(dev, "invalid pwm-polarity %d of %pOFn\n", val, child);
+ return -EINVAL;
+ }
+ data->pwm_polarity[i] = val;
+
+ 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, "channel"))
+ continue;
+
+ err = max6639_probe_child_from_dt(client, child, data);
+ if (err) {
+ of_node_put(child);
+ return err;
+ }
+ }
+
+ 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)
@@ -562,6 +620,24 @@ 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;
+ }
+
+ err = max6639_probe_from_dt(client, data);
+ if (err)
+ return err;
+
/* Initialize the max6639 chip */
err = max6639_init_client(client, data);
if (err < 0)
@@ -620,6 +696,14 @@ static const struct i2c_device_id max6639_id[] = {

MODULE_DEVICE_TABLE(i2c, max6639_id);

+#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 = {
@@ -627,6 +711,7 @@ static struct i2c_driver max6639_driver = {
.driver = {
.name = "max6639",
.pm = &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 */
--
2.33.1