This is a note to let you know that I've just added the patch titled hwmon: (jc42) Convert register access and caching to regmap/regcache to the 5.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: hwmon-jc42-convert-register-access-and-caching-to-re.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 1fcb0476a67414b7452a255290c5fdbe4dccd3ae Author: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> Date: Sun Oct 23 23:31:56 2022 +0200 hwmon: (jc42) Convert register access and caching to regmap/regcache [ Upstream commit 8f2fa4726faf01094d7a5be7bd0c120c565f54d9 ] Switch the jc42 driver to use an I2C regmap to access the registers. Also move over to regmap's built-in caching instead of adding a custom caching implementation. This works for JC42_REG_TEMP_UPPER, JC42_REG_TEMP_LOWER and JC42_REG_TEMP_CRITICAL as these values never change except when explicitly written. The cache For JC42_REG_TEMP is dropped (regmap can't cache it because it's volatile, meaning it can change at any time) as well for simplicity and consistency with other drivers. Signed-off-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20221023213157.11078-2-martin.blumenstingl@xxxxxxxxxxxxxx Signed-off-by: Guenter Roeck <linux@xxxxxxxxxxxx> Stable-dep-of: 084ed144c448 ("hwmon: (jc42) Restore the min/max/critical temperatures on resume") Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 51f1caa10d11..17ba1d9ff075 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -776,6 +776,7 @@ config SENSORS_IT87 config SENSORS_JC42 tristate "JEDEC JC42.4 compliant memory module temperature sensors" depends on I2C + select REGMAP_I2C help If you say yes here, you get support for JEDEC JC42.4 compliant temperature sensors, which are used on many DDR3 memory modules for diff --git a/drivers/hwmon/jc42.c b/drivers/hwmon/jc42.c index 4a03d010ec5a..9a2a062eb7b8 100644 --- a/drivers/hwmon/jc42.c +++ b/drivers/hwmon/jc42.c @@ -19,6 +19,7 @@ #include <linux/err.h> #include <linux/mutex.h> #include <linux/of.h> +#include <linux/regmap.h> /* Addresses to scan */ static const unsigned short normal_i2c[] = { @@ -189,31 +190,14 @@ static struct jc42_chips jc42_chips[] = { { STM_MANID, STTS3000_DEVID, STTS3000_DEVID_MASK }, }; -enum temp_index { - t_input = 0, - t_crit, - t_min, - t_max, - t_num_temp -}; - -static const u8 temp_regs[t_num_temp] = { - [t_input] = JC42_REG_TEMP, - [t_crit] = JC42_REG_TEMP_CRITICAL, - [t_min] = JC42_REG_TEMP_LOWER, - [t_max] = JC42_REG_TEMP_UPPER, -}; - /* Each client has this additional data */ struct jc42_data { - struct i2c_client *client; struct mutex update_lock; /* protect register access */ + struct regmap *regmap; bool extended; /* true if extended range supported */ bool valid; - unsigned long last_updated; /* In jiffies */ u16 orig_config; /* original configuration */ u16 config; /* current configuration */ - u16 temp[t_num_temp];/* Temperatures */ }; #define JC42_TEMP_MIN_EXTENDED (-40000) @@ -238,85 +222,102 @@ static int jc42_temp_from_reg(s16 reg) return reg * 125 / 2; } -static struct jc42_data *jc42_update_device(struct device *dev) -{ - struct jc42_data *data = dev_get_drvdata(dev); - struct i2c_client *client = data->client; - struct jc42_data *ret = data; - int i, val; - - mutex_lock(&data->update_lock); - - if (time_after(jiffies, data->last_updated + HZ) || !data->valid) { - for (i = 0; i < t_num_temp; i++) { - val = i2c_smbus_read_word_swapped(client, temp_regs[i]); - if (val < 0) { - ret = ERR_PTR(val); - goto abort; - } - data->temp[i] = val; - } - data->last_updated = jiffies; - data->valid = true; - } -abort: - mutex_unlock(&data->update_lock); - return ret; -} - static int jc42_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long *val) { - struct jc42_data *data = jc42_update_device(dev); - int temp, hyst; + struct jc42_data *data = dev_get_drvdata(dev); + unsigned int regval; + int ret, temp, hyst; - if (IS_ERR(data)) - return PTR_ERR(data); + mutex_lock(&data->update_lock); switch (attr) { case hwmon_temp_input: - *val = jc42_temp_from_reg(data->temp[t_input]); - return 0; + ret = regmap_read(data->regmap, JC42_REG_TEMP, ®val); + if (ret) + break; + + *val = jc42_temp_from_reg(regval); + break; case hwmon_temp_min: - *val = jc42_temp_from_reg(data->temp[t_min]); - return 0; + ret = regmap_read(data->regmap, JC42_REG_TEMP_LOWER, ®val); + if (ret) + break; + + *val = jc42_temp_from_reg(regval); + break; case hwmon_temp_max: - *val = jc42_temp_from_reg(data->temp[t_max]); - return 0; + ret = regmap_read(data->regmap, JC42_REG_TEMP_UPPER, ®val); + if (ret) + break; + + *val = jc42_temp_from_reg(regval); + break; case hwmon_temp_crit: - *val = jc42_temp_from_reg(data->temp[t_crit]); - return 0; + ret = regmap_read(data->regmap, JC42_REG_TEMP_CRITICAL, + ®val); + if (ret) + break; + + *val = jc42_temp_from_reg(regval); + break; case hwmon_temp_max_hyst: - temp = jc42_temp_from_reg(data->temp[t_max]); + ret = regmap_read(data->regmap, JC42_REG_TEMP_UPPER, ®val); + if (ret) + break; + + temp = jc42_temp_from_reg(regval); hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK) >> JC42_CFG_HYST_SHIFT]; *val = temp - hyst; - return 0; + break; case hwmon_temp_crit_hyst: - temp = jc42_temp_from_reg(data->temp[t_crit]); + ret = regmap_read(data->regmap, JC42_REG_TEMP_CRITICAL, + ®val); + if (ret) + break; + + temp = jc42_temp_from_reg(regval); hyst = jc42_hysteresis[(data->config & JC42_CFG_HYST_MASK) >> JC42_CFG_HYST_SHIFT]; *val = temp - hyst; - return 0; + break; case hwmon_temp_min_alarm: - *val = (data->temp[t_input] >> JC42_ALARM_MIN_BIT) & 1; - return 0; + ret = regmap_read(data->regmap, JC42_REG_TEMP, ®val); + if (ret) + break; + + *val = (regval >> JC42_ALARM_MIN_BIT) & 1; + break; case hwmon_temp_max_alarm: - *val = (data->temp[t_input] >> JC42_ALARM_MAX_BIT) & 1; - return 0; + ret = regmap_read(data->regmap, JC42_REG_TEMP, ®val); + if (ret) + break; + + *val = (regval >> JC42_ALARM_MAX_BIT) & 1; + break; case hwmon_temp_crit_alarm: - *val = (data->temp[t_input] >> JC42_ALARM_CRIT_BIT) & 1; - return 0; + ret = regmap_read(data->regmap, JC42_REG_TEMP, ®val); + if (ret) + break; + + *val = (regval >> JC42_ALARM_CRIT_BIT) & 1; + break; default: - return -EOPNOTSUPP; + ret = -EOPNOTSUPP; + break; } + + mutex_unlock(&data->update_lock); + + return ret; } static int jc42_write(struct device *dev, enum hwmon_sensor_types type, u32 attr, int channel, long val) { struct jc42_data *data = dev_get_drvdata(dev); - struct i2c_client *client = data->client; + unsigned int regval; int diff, hyst; int ret; @@ -324,21 +325,23 @@ static int jc42_write(struct device *dev, enum hwmon_sensor_types type, switch (attr) { case hwmon_temp_min: - data->temp[t_min] = jc42_temp_to_reg(val, data->extended); - ret = i2c_smbus_write_word_swapped(client, temp_regs[t_min], - data->temp[t_min]); + ret = regmap_write(data->regmap, JC42_REG_TEMP_LOWER, + jc42_temp_to_reg(val, data->extended)); break; case hwmon_temp_max: - data->temp[t_max] = jc42_temp_to_reg(val, data->extended); - ret = i2c_smbus_write_word_swapped(client, temp_regs[t_max], - data->temp[t_max]); + ret = regmap_write(data->regmap, JC42_REG_TEMP_UPPER, + jc42_temp_to_reg(val, data->extended)); break; case hwmon_temp_crit: - data->temp[t_crit] = jc42_temp_to_reg(val, data->extended); - ret = i2c_smbus_write_word_swapped(client, temp_regs[t_crit], - data->temp[t_crit]); + ret = regmap_write(data->regmap, JC42_REG_TEMP_CRITICAL, + jc42_temp_to_reg(val, data->extended)); break; case hwmon_temp_crit_hyst: + ret = regmap_read(data->regmap, JC42_REG_TEMP_CRITICAL, + ®val); + if (ret) + return ret; + /* * JC42.4 compliant chips only support four hysteresis values. * Pick best choice and go from there. @@ -346,7 +349,7 @@ static int jc42_write(struct device *dev, enum hwmon_sensor_types type, val = clamp_val(val, (data->extended ? JC42_TEMP_MIN_EXTENDED : JC42_TEMP_MIN) - 6000, JC42_TEMP_MAX); - diff = jc42_temp_from_reg(data->temp[t_crit]) - val; + diff = jc42_temp_from_reg(regval) - val; hyst = 0; if (diff > 0) { if (diff < 2250) @@ -358,9 +361,8 @@ static int jc42_write(struct device *dev, enum hwmon_sensor_types type, } data->config = (data->config & ~JC42_CFG_HYST_MASK) | (hyst << JC42_CFG_HYST_SHIFT); - ret = i2c_smbus_write_word_swapped(data->client, - JC42_REG_CONFIG, - data->config); + ret = regmap_write(data->regmap, JC42_REG_CONFIG, + data->config); break; default: ret = -EOPNOTSUPP; @@ -458,51 +460,80 @@ static const struct hwmon_chip_info jc42_chip_info = { .info = jc42_info, }; +static bool jc42_readable_reg(struct device *dev, unsigned int reg) +{ + return (reg >= JC42_REG_CAP && reg <= JC42_REG_DEVICEID) || + reg == JC42_REG_SMBUS; +} + +static bool jc42_writable_reg(struct device *dev, unsigned int reg) +{ + return (reg >= JC42_REG_CONFIG && reg <= JC42_REG_TEMP_CRITICAL) || + reg == JC42_REG_SMBUS; +} + +static bool jc42_volatile_reg(struct device *dev, unsigned int reg) +{ + return reg == JC42_REG_CONFIG || reg == JC42_REG_TEMP; +} + +static const struct regmap_config jc42_regmap_config = { + .reg_bits = 8, + .val_bits = 16, + .val_format_endian = REGMAP_ENDIAN_BIG, + .max_register = JC42_REG_SMBUS, + .writeable_reg = jc42_writable_reg, + .readable_reg = jc42_readable_reg, + .volatile_reg = jc42_volatile_reg, + .cache_type = REGCACHE_RBTREE, +}; + static int jc42_probe(struct i2c_client *client) { struct device *dev = &client->dev; struct device *hwmon_dev; + unsigned int config, cap; struct jc42_data *data; - int config, cap; + int ret; data = devm_kzalloc(dev, sizeof(struct jc42_data), GFP_KERNEL); if (!data) return -ENOMEM; - data->client = client; + data->regmap = devm_regmap_init_i2c(client, &jc42_regmap_config); + if (IS_ERR(data->regmap)) + return PTR_ERR(data->regmap); + i2c_set_clientdata(client, data); mutex_init(&data->update_lock); - cap = i2c_smbus_read_word_swapped(client, JC42_REG_CAP); - if (cap < 0) - return cap; + ret = regmap_read(data->regmap, JC42_REG_CAP, &cap); + if (ret) + return ret; data->extended = !!(cap & JC42_CAP_RANGE); if (device_property_read_bool(dev, "smbus-timeout-disable")) { - int smbus; - /* * Not all chips support this register, but from a * quick read of various datasheets no chip appears * incompatible with the below attempt to disable * the timeout. And the whole thing is opt-in... */ - smbus = i2c_smbus_read_word_swapped(client, JC42_REG_SMBUS); - if (smbus < 0) - return smbus; - i2c_smbus_write_word_swapped(client, JC42_REG_SMBUS, - smbus | SMBUS_STMOUT); + ret = regmap_set_bits(data->regmap, JC42_REG_SMBUS, + SMBUS_STMOUT); + if (ret) + return ret; } - config = i2c_smbus_read_word_swapped(client, JC42_REG_CONFIG); - if (config < 0) - return config; + ret = regmap_read(data->regmap, JC42_REG_CONFIG, &config); + if (ret) + return ret; data->orig_config = config; if (config & JC42_CFG_SHUTDOWN) { config &= ~JC42_CFG_SHUTDOWN; - i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config); + regmap_write(data->regmap, JC42_REG_CONFIG, config); } data->config = config; @@ -523,7 +554,7 @@ static int jc42_remove(struct i2c_client *client) config = (data->orig_config & ~JC42_CFG_HYST_MASK) | (data->config & JC42_CFG_HYST_MASK); - i2c_smbus_write_word_swapped(client, JC42_REG_CONFIG, config); + regmap_write(data->regmap, JC42_REG_CONFIG, config); } return 0; } @@ -535,8 +566,7 @@ static int jc42_suspend(struct device *dev) struct jc42_data *data = dev_get_drvdata(dev); data->config |= JC42_CFG_SHUTDOWN; - i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG, - data->config); + regmap_write(data->regmap, JC42_REG_CONFIG, data->config); return 0; } @@ -545,8 +575,7 @@ static int jc42_resume(struct device *dev) struct jc42_data *data = dev_get_drvdata(dev); data->config &= ~JC42_CFG_SHUTDOWN; - i2c_smbus_write_word_swapped(data->client, JC42_REG_CONFIG, - data->config); + regmap_write(data->regmap, JC42_REG_CONFIG, data->config); return 0; }