[PATCH v2 1/5] hwmon: (max31790) Rework to use regmap

Václav Kubernát
2021-03-16T17:56:56Z

Converting the driver to use regmap makes it more generic. It also makes
it a lot easier to debug through debugfs.

Signed-off-by: Václav Kubernát <kubernat@cesnet.cz>
---
drivers/hwmon/Kconfig | 1 +
drivers/hwmon/max31790.c | 318 ++++++++++++++++++++-------------------
2 files changed, 163 insertions(+), 156 deletions(-)

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 54f04e61fb83..c2ec57672c4e 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1092,6 +1092,7 @@ config SENSORS_MAX6697
config SENSORS_MAX31790
tristate "Maxim MAX31790 sensor chip"
depends on I2C
+ select REGMAP_I2C
help
If you say yes here you get support for 6-Channel PWM-Output
Fan RPM Controller.
diff --git a/drivers/hwmon/max31790.c b/drivers/hwmon/max31790.c
index 86e6c71db685..4e5add567890 100644
--- a/drivers/hwmon/max31790.c
+++ b/drivers/hwmon/max31790.c
@@ -12,6 +12,7 @@
#include <linux/init.h>
#include <linux/jiffies.h>
#include <linux/module.h>
+#include <linux/regmap.h>
#include <linux/slab.h>

/* MAX31790 registers */
@@ -46,92 +47,49 @@

#define NR_CHANNEL 6

+#define MAX31790_REG_USER_BYTE_67 0x67
+
+#define BULK_TO_U16(msb, lsb) (((msb) << 8) + (lsb))
+#define U16_MSB(num) (((num) & 0xFF00) >> 8)
+#define U16_LSB(num) ((num) & 0x00FF)
+
+static const struct regmap_range max31790_ro_range = {
+ .range_min = MAX31790_REG_TACH_COUNT(0),
+ .range_max = MAX31790_REG_PWMOUT(0) - 1,
+};
+
+static const struct regmap_access_table max31790_wr_table = {
+ .no_ranges = &max31790_ro_range,
+ .n_no_ranges = 1,
+};
+
+static const struct regmap_range max31790_volatile_ranges[] = {
+ regmap_reg_range(MAX31790_REG_TACH_COUNT(0), MAX31790_REG_TACH_COUNT(12)),
+ regmap_reg_range(MAX31790_REG_FAN_FAULT_STATUS2, MAX31790_REG_FAN_FAULT_STATUS1),
+};
+
+static const struct regmap_access_table max31790_volatile_table = {
+ .no_ranges = max31790_volatile_ranges,
+ .n_no_ranges = 2,
+ .n_yes_ranges = 0
+};
+
+static const struct regmap_config max31790_regmap_config = {
+ .reg_bits = 8,
+ .val_bits = 8,
+ .reg_stride = 1,
+ .max_register = MAX31790_REG_USER_BYTE_67,
+ .wr_table = &max31790_wr_table,
+ .volatile_table = &max31790_volatile_table
+};
+
/*
* Client data (each client gets its own)
*/
struct max31790_data {
- struct i2c_client *client;
- struct mutex update_lock;
- bool valid; /* zero until following fields are valid */
- unsigned long last_updated; /* in jiffies */
-
- /* register values */
- u8 fan_config[NR_CHANNEL];
- u8 fan_dynamics[NR_CHANNEL];
- u16 fault_status;
- u16 tach[NR_CHANNEL * 2];
- u16 pwm[NR_CHANNEL];
- u16 target_count[NR_CHANNEL];
+ struct regmap *regmap;
};

-static struct max31790_data *max31790_update_device(struct device *dev)
-{
- struct max31790_data *data = dev_get_drvdata(dev);
- struct i2c_client *client = data->client;
- struct max31790_data *ret = data;
- int i;
- int rv;
-
- mutex_lock(&data->update_lock);
-
- if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {
- rv = i2c_smbus_read_byte_data(client,
- MAX31790_REG_FAN_FAULT_STATUS1);
- if (rv < 0)
- goto abort;
- data->fault_status = rv & 0x3F;
-
- rv = i2c_smbus_read_byte_data(client,
- MAX31790_REG_FAN_FAULT_STATUS2);
- if (rv < 0)
- goto abort;
- data->fault_status |= (rv & 0x3F) << 6;
-
- for (i = 0; i < NR_CHANNEL; i++) {
- rv = i2c_smbus_read_word_swapped(client,
- MAX31790_REG_TACH_COUNT(i));
- if (rv < 0)
- goto abort;
- data->tach[i] = rv;
-
- if (data->fan_config[i]
- & MAX31790_FAN_CFG_TACH_INPUT) {
- rv = i2c_smbus_read_word_swapped(client,
- MAX31790_REG_TACH_COUNT(NR_CHANNEL
- + i));
- if (rv < 0)
- goto abort;
- data->tach[NR_CHANNEL + i] = rv;
- } else {
- rv = i2c_smbus_read_word_swapped(client,
- MAX31790_REG_PWMOUT(i));
- if (rv < 0)
- goto abort;
- data->pwm[i] = rv;
-
- rv = i2c_smbus_read_word_swapped(client,
- MAX31790_REG_TARGET_COUNT(i));
- if (rv < 0)
- goto abort;
- data->target_count[i] = rv;
- }
- }
-
- data->last_updated = jiffies;
- data->valid = true;
- }
- goto done;
-
-abort:
- data->valid = false;
- ret = ERR_PTR(rv);
-
-done:
- mutex_unlock(&data->update_lock);
-
- return ret;
-}
-
static const u8 tach_period[8] = { 1, 2, 4, 8, 16, 32, 32, 32 };

static u8 get_tach_period(u8 fan_dynamics)
@@ -159,28 +117,89 @@ static u8 bits_for_tach_period(int rpm)
return bits;
}

+static int read_reg_byte(struct regmap *regmap, u8 reg)
+{
+ int rv;
+ int val;
+
+ rv = regmap_read(regmap, reg, &val);
+
+ if (rv < 0)
+ return rv;
+
+ return val;
+}
+
+static int read_reg_word(struct regmap *regmap, u8 reg)
+{
+ int rv;
+ u8 val_bulk[2];
+
+ rv = regmap_bulk_read(regmap, reg, val_bulk, 2);
+ if (rv < 0)
+ return rv;
+
+ return BULK_TO_U16(val_bulk[0], val_bulk[1]);
+}
+
+static int write_reg_word(struct regmap *regmap, u8 reg, u16 val)
+{
+ u8 bulk_val[2];
+
+ bulk_val[0] = U16_MSB(val);
+ bulk_val[1] = U16_LSB(val);
+
+ return regmap_bulk_write(regmap, reg, bulk_val, 2);
+}
+
static int max31790_read_fan(struct device *dev, u32 attr, int channel,
long *val)
{
- struct max31790_data *data = max31790_update_device(dev);
- int sr, rpm;
+ struct max31790_data *data = dev_get_drvdata(dev);
+ struct regmap *regmap = data->regmap;
+ int rpm, dynamics, tach, fault;

if (IS_ERR(data))
return PTR_ERR(data);

switch (attr) {
case hwmon_fan_input:
- sr = get_tach_period(data->fan_dynamics[channel]);
- rpm = RPM_FROM_REG(data->tach[channel], sr);
+ dynamics = read_reg_byte(regmap, MAX31790_REG_FAN_DYNAMICS(channel));
+ if (dynamics < 0)
+ return dynamics;
+
+ tach = read_reg_word(regmap, MAX31790_REG_TACH_COUNT(channel));
+ if (tach < 0)
+ return tach;
+
+ rpm = RPM_FROM_REG(tach, get_tach_period(dynamics));
*val = rpm;
return 0;
case hwmon_fan_target:
- sr = get_tach_period(data->fan_dynamics[channel]);
- rpm = RPM_FROM_REG(data->target_count[channel], sr);
+ dynamics = read_reg_byte(regmap, MAX31790_REG_FAN_DYNAMICS(channel));
+ if (dynamics < 0)
+ return dynamics;
+
+ tach = read_reg_word(regmap, MAX31790_REG_TARGET_COUNT(channel));
+ if (tach < 0)
+ return tach;
+
+ rpm = RPM_FROM_REG(tach, get_tach_period(dynamics));
*val = rpm;
return 0;
case hwmon_fan_fault:
- *val = !!(data->fault_status & (1 << channel));
+ if (channel > 6)
+ fault = read_reg_byte(regmap, MAX31790_REG_FAN_FAULT_STATUS2);
+ else
+ fault = read_reg_byte(regmap, MAX31790_REG_FAN_FAULT_STATUS1);
+
+ if (fault < 0)
+ return fault;
+
+ if (channel > 6)
+ *val = !!(fault & (1 << (channel - 6)));
+ else
+ *val = !!(fault & (1 << channel));
return 0;
default:
return -EOPNOTSUPP;
@@ -191,52 +210,58 @@ static int max31790_write_fan(struct device *dev, u32 attr, int channel,
long val)
{
struct max31790_data *data = dev_get_drvdata(dev);
- struct i2c_client *client = data->client;
+ struct regmap *regmap = data->regmap;
int target_count;
int err = 0;
u8 bits;
int sr;
-
- mutex_lock(&data->update_lock);
+ int fan_dynamics;

switch (attr) {
case hwmon_fan_target:
val = clamp_val(val, FAN_RPM_MIN, FAN_RPM_MAX);
bits = bits_for_tach_period(val);
- data->fan_dynamics[channel] =
- ((data->fan_dynamics[channel] &
+ fan_dynamics = read_reg_byte(regmap, MAX31790_REG_FAN_DYNAMICS(channel));
+
+ if (fan_dynamics < 0)
+ return fan_dynamics;
+
+ fan_dynamics =
+ ((fan_dynamics &
~MAX31790_FAN_DYN_SR_MASK) |
(bits << MAX31790_FAN_DYN_SR_SHIFT));
- err = i2c_smbus_write_byte_data(client,
- MAX31790_REG_FAN_DYNAMICS(channel),
- data->fan_dynamics[channel]);
+ err = regmap_write(regmap,
+ MAX31790_REG_FAN_DYNAMICS(channel),
+ fan_dynamics);
if (err < 0)
break;

- sr = get_tach_period(data->fan_dynamics[channel]);
+ sr = get_tach_period(fan_dynamics);
target_count = RPM_TO_REG(val, sr);
target_count = clamp_val(target_count, 0x1, 0x7FF);

- data->target_count[channel] = target_count << 5;
+ target_count = target_count << 5;

- err = i2c_smbus_write_word_swapped(client,
- MAX31790_REG_TARGET_COUNT(channel),
- data->target_count[channel]);
+ err = write_reg_word(regmap,
+ MAX31790_REG_TARGET_COUNT(channel),
+ target_count);
break;
default:
err = -EOPNOTSUPP;
break;
}

- mutex_unlock(&data->update_lock);
-
return err;
}

static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
{
const struct max31790_data *data = _data;
- u8 fan_config = data->fan_config[channel % NR_CHANNEL];
+ struct regmap *regmap = data->regmap;
+ u8 fan_config = read_reg_byte(regmap, MAX31790_REG_FAN_CONFIG(channel % NR_CHANNEL));
+
+ if (fan_config < 0)
+ return 0;

switch (attr) {
case hwmon_fan_input:
@@ -258,22 +283,29 @@ static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
static int max31790_read_pwm(struct device *dev, u32 attr, int channel,
long *val)
{
- struct max31790_data *data = max31790_update_device(dev);
- u8 fan_config;
+ struct max31790_data *data = dev_get_drvdata(dev);
+ struct regmap *regmap = data->regmap;
+ int read;

if (IS_ERR(data))
return PTR_ERR(data);

- fan_config = data->fan_config[channel];
-
switch (attr) {
case hwmon_pwm_input:
- *val = data->pwm[channel] >> 8;
+ read = read_reg_word(regmap, MAX31790_REG_PWMOUT(channel));
+ if (read < 0)
+ return read;
+
+ *val = read >> 8;
return 0;
case hwmon_pwm_enable:
- if (fan_config & MAX31790_FAN_CFG_RPM_MODE)
+ read = read_reg_byte(regmap, MAX31790_REG_FAN_CONFIG(channel));
+ if (read < 0)
+ return read;
+
+ if (read & MAX31790_FAN_CFG_RPM_MODE)
*val = 2;
- else if (fan_config & MAX31790_FAN_CFG_TACH_INPUT_EN)
+ else if (read & MAX31790_FAN_CFG_TACH_INPUT_EN)
*val = 1;
else
*val = 0;
@@ -287,25 +319,24 @@ static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
long val)
{
struct max31790_data *data = dev_get_drvdata(dev);
- struct i2c_client *client = data->client;
+ struct regmap *regmap = data->regmap;
u8 fan_config;
int err = 0;

- mutex_lock(&data->update_lock);
-
switch (attr) {
case hwmon_pwm_input:
if (val < 0 || val > 255) {
err = -EINVAL;
break;
}
- data->pwm[channel] = val << 8;
- err = i2c_smbus_write_word_swapped(client,
- MAX31790_REG_PWMOUT(channel),
- data->pwm[channel]);
+ err = write_reg_word(regmap, MAX31790_REG_PWMOUT(channel), val << 8);
break;
case hwmon_pwm_enable:
- fan_config = data->fan_config[channel];
+ fan_config = read_reg_byte(regmap, MAX31790_REG_FAN_CONFIG(channel % NR_CHANNEL));
+
+ if (fan_config < 0)
+ return fan_config;
+
if (val == 0) {
fan_config &= ~(MAX31790_FAN_CFG_TACH_INPUT_EN |
MAX31790_FAN_CFG_RPM_MODE);
@@ -320,25 +351,26 @@ static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
err = -EINVAL;
break;
}
- data->fan_config[channel] = fan_config;
- err = i2c_smbus_write_byte_data(client,
- MAX31790_REG_FAN_CONFIG(channel),
- fan_config);
+ err = regmap_write(regmap,
+ MAX31790_REG_FAN_CONFIG(channel),
+ fan_config);
break;
default:
err = -EOPNOTSUPP;
break;
}

- mutex_unlock(&data->update_lock);
-
return err;
}

static umode_t max31790_pwm_is_visible(const void *_data, u32 attr, int channel)
{
const struct max31790_data *data = _data;
- u8 fan_config = data->fan_config[channel];
+ struct regmap *regmap = data->regmap;
+ u8 fan_config = read_reg_byte(regmap, MAX31790_REG_FAN_CONFIG(channel % NR_CHANNEL));
+
+ if (fan_config < 0)
+ return 0;

switch (attr) {
case hwmon_pwm_input:
@@ -426,35 +458,12 @@ static const struct hwmon_chip_info max31790_chip_info = {
.info = max31790_info,
};

-static int max31790_init_client(struct i2c_client *client,
- struct max31790_data *data)
-{
- int i, rv;
-
- for (i = 0; i < NR_CHANNEL; i++) {
- rv = i2c_smbus_read_byte_data(client,
- MAX31790_REG_FAN_CONFIG(i));
- if (rv < 0)
- return rv;
- data->fan_config[i] = rv;
-
- rv = i2c_smbus_read_byte_data(client,
- MAX31790_REG_FAN_DYNAMICS(i));
- if (rv < 0)
- return rv;
- data->fan_dynamics[i] = rv;
- }
-
- return 0;
-}
-
static int max31790_probe(struct i2c_client *client)
{
struct i2c_adapter *adapter = client->adapter;
struct device *dev = &client->dev;
struct max31790_data *data;
struct device *hwmon_dev;
- int err;

if (!i2c_check_functionality(adapter,
I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA))
@@ -464,15 +473,12 @@ static int max31790_probe(struct i2c_client *client)
if (!data)
return -ENOMEM;

- data->client = client;
- mutex_init(&data->update_lock);
+ data->regmap = devm_regmap_init_i2c(client, &max31790_regmap_config);

- /*
- * Initialize the max31790 chip
- */
- err = max31790_init_client(client, data);
- if (err)
- return err;
+ if (IS_ERR(data->regmap)) {
+ dev_err(dev, "failed to allocate register map\n");
+ return PTR_ERR(data->regmap);
+ }

hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name,
data,
--
2.30.2