diff mbox series

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

Message ID 20210316175503.1003051-1-kubernat@cesnet.cz (mailing list archive)
State Changes Requested
Headers show
Series [v2,1/5] hwmon: (max31790) Rework to use regmap | expand

Commit Message

Václav Kubernát March 16, 2021, 5:54 p.m. UTC
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(-)

Comments

Václav Kubernát March 16, 2021, 6:11 p.m. UTC | #1
Hi Guenther,

I'm posting v2 of my series on max31790. These are the changes from v1:
1) The driver uses regmap caching instead of local caching.
2) I got rid of the "refactor" patch and also the "pulses" patch.
3) I got rid of unnecessary whitespace changes.
4) fan*_input now returns -ENODATA when fan*_enable is 0.
5) Changed the argument of bits_for_speed_range to long.

Vaclav
Dan Carpenter March 17, 2021, 5:12 a.m. UTC | #2
Hi "Václav,

url:    https://github.com/0day-ci/linux/commits/V-clav-Kubern-t/hwmon-max31790-Rework-to-use-regmap/20210317-015931
base:   https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
config: x86_64-randconfig-m001-20210316 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-22) 9.3.0

If you fix the issue, kindly add following tag as appropriate
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>

smatch warnings:
drivers/hwmon/max31790.c:263 max31790_fan_is_visible() warn: impossible condition '(fan_config < 0) => (0-255 < 0)'
drivers/hwmon/max31790.c:337 max31790_write_pwm() warn: impossible condition '(fan_config < 0) => (0-255 < 0)'
drivers/hwmon/max31790.c:372 max31790_pwm_is_visible() warn: impossible condition '(fan_config < 0) => (0-255 < 0)'

vim +263 drivers/hwmon/max31790.c

54187ff9d766b2 Guenter Roeck   2016-07-01  257  static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
195a4b4298a795 Il Han          2015-08-30  258  {
54187ff9d766b2 Guenter Roeck   2016-07-01  259  	const struct max31790_data *data = _data;
2c8602cfaeab63 Václav Kubernát 2021-03-16  260  	struct regmap *regmap = data->regmap;
2c8602cfaeab63 Václav Kubernát 2021-03-16  261  	u8 fan_config = read_reg_byte(regmap, MAX31790_REG_FAN_CONFIG(channel % NR_CHANNEL));
2c8602cfaeab63 Václav Kubernát 2021-03-16  262  
2c8602cfaeab63 Václav Kubernát 2021-03-16 @263  	if (fan_config < 0)
                                                            ^^^^^^^^^^^^^^
A u8 can't be negative.

2c8602cfaeab63 Václav Kubernát 2021-03-16  264  		return 0;
54187ff9d766b2 Guenter Roeck   2016-07-01  265  
54187ff9d766b2 Guenter Roeck   2016-07-01  266  	switch (attr) {
54187ff9d766b2 Guenter Roeck   2016-07-01  267  	case hwmon_fan_input:
54187ff9d766b2 Guenter Roeck   2016-07-01  268  	case hwmon_fan_fault:
54187ff9d766b2 Guenter Roeck   2016-07-01  269  		if (channel < NR_CHANNEL ||
54187ff9d766b2 Guenter Roeck   2016-07-01  270  		    (fan_config & MAX31790_FAN_CFG_TACH_INPUT))
dc8dbb4d7672b7 Guenter Roeck   2018-12-10  271  			return 0444;
54187ff9d766b2 Guenter Roeck   2016-07-01  272  		return 0;
54187ff9d766b2 Guenter Roeck   2016-07-01  273  	case hwmon_fan_target:
54187ff9d766b2 Guenter Roeck   2016-07-01  274  		if (channel < NR_CHANNEL &&
54187ff9d766b2 Guenter Roeck   2016-07-01  275  		    !(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
dc8dbb4d7672b7 Guenter Roeck   2018-12-10  276  			return 0644;
54187ff9d766b2 Guenter Roeck   2016-07-01  277  		return 0;
54187ff9d766b2 Guenter Roeck   2016-07-01  278  	default:
54187ff9d766b2 Guenter Roeck   2016-07-01  279  		return 0;
195a4b4298a795 Il Han          2015-08-30  280  	}
195a4b4298a795 Il Han          2015-08-30  281  }
195a4b4298a795 Il Han          2015-08-30  282  
54187ff9d766b2 Guenter Roeck   2016-07-01  283  static int max31790_read_pwm(struct device *dev, u32 attr, int channel,
54187ff9d766b2 Guenter Roeck   2016-07-01  284  			     long *val)
195a4b4298a795 Il Han          2015-08-30  285  {
2c8602cfaeab63 Václav Kubernát 2021-03-16  286  	struct max31790_data *data = dev_get_drvdata(dev);
2c8602cfaeab63 Václav Kubernát 2021-03-16  287  	struct regmap *regmap = data->regmap;
2c8602cfaeab63 Václav Kubernát 2021-03-16  288  	int read;
195a4b4298a795 Il Han          2015-08-30  289  
195a4b4298a795 Il Han          2015-08-30  290  	if (IS_ERR(data))
195a4b4298a795 Il Han          2015-08-30  291  		return PTR_ERR(data);
195a4b4298a795 Il Han          2015-08-30  292  
54187ff9d766b2 Guenter Roeck   2016-07-01  293  	switch (attr) {
54187ff9d766b2 Guenter Roeck   2016-07-01  294  	case hwmon_pwm_input:
2c8602cfaeab63 Václav Kubernát 2021-03-16  295  		read = read_reg_word(regmap, MAX31790_REG_PWMOUT(channel));
2c8602cfaeab63 Václav Kubernát 2021-03-16  296  		if (read < 0)
2c8602cfaeab63 Václav Kubernát 2021-03-16  297  			return read;
2c8602cfaeab63 Václav Kubernát 2021-03-16  298  
2c8602cfaeab63 Václav Kubernát 2021-03-16  299  		*val = read >> 8;
54187ff9d766b2 Guenter Roeck   2016-07-01  300  		return 0;
54187ff9d766b2 Guenter Roeck   2016-07-01  301  	case hwmon_pwm_enable:
2c8602cfaeab63 Václav Kubernát 2021-03-16  302  		read = read_reg_byte(regmap, MAX31790_REG_FAN_CONFIG(channel));
2c8602cfaeab63 Václav Kubernát 2021-03-16  303  		if (read < 0)
2c8602cfaeab63 Václav Kubernát 2021-03-16  304  			return read;
2c8602cfaeab63 Václav Kubernát 2021-03-16  305  
2c8602cfaeab63 Václav Kubernát 2021-03-16  306  		if (read & MAX31790_FAN_CFG_RPM_MODE)
54187ff9d766b2 Guenter Roeck   2016-07-01  307  			*val = 2;
2c8602cfaeab63 Václav Kubernát 2021-03-16  308  		else if (read & MAX31790_FAN_CFG_TACH_INPUT_EN)
54187ff9d766b2 Guenter Roeck   2016-07-01  309  			*val = 1;
195a4b4298a795 Il Han          2015-08-30  310  		else
54187ff9d766b2 Guenter Roeck   2016-07-01  311  			*val = 0;
54187ff9d766b2 Guenter Roeck   2016-07-01  312  		return 0;
54187ff9d766b2 Guenter Roeck   2016-07-01  313  	default:
54187ff9d766b2 Guenter Roeck   2016-07-01  314  		return -EOPNOTSUPP;
54187ff9d766b2 Guenter Roeck   2016-07-01  315  	}
195a4b4298a795 Il Han          2015-08-30  316  }
195a4b4298a795 Il Han          2015-08-30  317  
54187ff9d766b2 Guenter Roeck   2016-07-01  318  static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
54187ff9d766b2 Guenter Roeck   2016-07-01  319  			      long val)
195a4b4298a795 Il Han          2015-08-30  320  {
195a4b4298a795 Il Han          2015-08-30  321  	struct max31790_data *data = dev_get_drvdata(dev);
2c8602cfaeab63 Václav Kubernát 2021-03-16  322  	struct regmap *regmap = data->regmap;
54187ff9d766b2 Guenter Roeck   2016-07-01  323  	u8 fan_config;
54187ff9d766b2 Guenter Roeck   2016-07-01  324  	int err = 0;
195a4b4298a795 Il Han          2015-08-30  325  
54187ff9d766b2 Guenter Roeck   2016-07-01  326  	switch (attr) {
54187ff9d766b2 Guenter Roeck   2016-07-01  327  	case hwmon_pwm_input:
54187ff9d766b2 Guenter Roeck   2016-07-01  328  		if (val < 0 || val > 255) {
54187ff9d766b2 Guenter Roeck   2016-07-01  329  			err = -EINVAL;
54187ff9d766b2 Guenter Roeck   2016-07-01  330  			break;
54187ff9d766b2 Guenter Roeck   2016-07-01  331  		}
2c8602cfaeab63 Václav Kubernát 2021-03-16  332  		err = write_reg_word(regmap, MAX31790_REG_PWMOUT(channel), val << 8);
195a4b4298a795 Il Han          2015-08-30  333  		break;
54187ff9d766b2 Guenter Roeck   2016-07-01  334  	case hwmon_pwm_enable:
2c8602cfaeab63 Václav Kubernát 2021-03-16  335  		fan_config = read_reg_byte(regmap, MAX31790_REG_FAN_CONFIG(channel % NR_CHANNEL));
2c8602cfaeab63 Václav Kubernát 2021-03-16  336  
2c8602cfaeab63 Václav Kubernát 2021-03-16 @337  		if (fan_config < 0)
2c8602cfaeab63 Václav Kubernát 2021-03-16  338  			return fan_config;
2c8602cfaeab63 Václav Kubernát 2021-03-16  339  
54187ff9d766b2 Guenter Roeck   2016-07-01  340  		if (val == 0) {
54187ff9d766b2 Guenter Roeck   2016-07-01  341  			fan_config &= ~(MAX31790_FAN_CFG_TACH_INPUT_EN |
54187ff9d766b2 Guenter Roeck   2016-07-01  342  					MAX31790_FAN_CFG_RPM_MODE);
54187ff9d766b2 Guenter Roeck   2016-07-01  343  		} else if (val == 1) {
54187ff9d766b2 Guenter Roeck   2016-07-01  344  			fan_config = (fan_config |
54187ff9d766b2 Guenter Roeck   2016-07-01  345  				      MAX31790_FAN_CFG_TACH_INPUT_EN) &
54187ff9d766b2 Guenter Roeck   2016-07-01  346  				     ~MAX31790_FAN_CFG_RPM_MODE;
54187ff9d766b2 Guenter Roeck   2016-07-01  347  		} else if (val == 2) {
54187ff9d766b2 Guenter Roeck   2016-07-01  348  			fan_config |= MAX31790_FAN_CFG_TACH_INPUT_EN |
54187ff9d766b2 Guenter Roeck   2016-07-01  349  				      MAX31790_FAN_CFG_RPM_MODE;
54187ff9d766b2 Guenter Roeck   2016-07-01  350  		} else {
54187ff9d766b2 Guenter Roeck   2016-07-01  351  			err = -EINVAL;
195a4b4298a795 Il Han          2015-08-30  352  			break;
54187ff9d766b2 Guenter Roeck   2016-07-01  353  		}
2c8602cfaeab63 Václav Kubernát 2021-03-16  354  		err = regmap_write(regmap,
54187ff9d766b2 Guenter Roeck   2016-07-01  355  				   MAX31790_REG_FAN_CONFIG(channel),
54187ff9d766b2 Guenter Roeck   2016-07-01  356  				   fan_config);
195a4b4298a795 Il Han          2015-08-30  357  		break;
195a4b4298a795 Il Han          2015-08-30  358  	default:
54187ff9d766b2 Guenter Roeck   2016-07-01  359  		err = -EOPNOTSUPP;
54187ff9d766b2 Guenter Roeck   2016-07-01  360  		break;
195a4b4298a795 Il Han          2015-08-30  361  	}
195a4b4298a795 Il Han          2015-08-30  362  
195a4b4298a795 Il Han          2015-08-30  363  	return err;
195a4b4298a795 Il Han          2015-08-30  364  }
195a4b4298a795 Il Han          2015-08-30  365  
54187ff9d766b2 Guenter Roeck   2016-07-01  366  static umode_t max31790_pwm_is_visible(const void *_data, u32 attr, int channel)
195a4b4298a795 Il Han          2015-08-30  367  {
54187ff9d766b2 Guenter Roeck   2016-07-01  368  	const struct max31790_data *data = _data;
2c8602cfaeab63 Václav Kubernát 2021-03-16  369  	struct regmap *regmap = data->regmap;
2c8602cfaeab63 Václav Kubernát 2021-03-16  370  	u8 fan_config = read_reg_byte(regmap, MAX31790_REG_FAN_CONFIG(channel % NR_CHANNEL));
2c8602cfaeab63 Václav Kubernát 2021-03-16  371  
2c8602cfaeab63 Václav Kubernát 2021-03-16 @372  	if (fan_config < 0)
2c8602cfaeab63 Václav Kubernát 2021-03-16  373  		return 0;
54187ff9d766b2 Guenter Roeck   2016-07-01  374  
54187ff9d766b2 Guenter Roeck   2016-07-01  375  	switch (attr) {
54187ff9d766b2 Guenter Roeck   2016-07-01  376  	case hwmon_pwm_input:
54187ff9d766b2 Guenter Roeck   2016-07-01  377  	case hwmon_pwm_enable:
54187ff9d766b2 Guenter Roeck   2016-07-01  378  		if (!(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
dc8dbb4d7672b7 Guenter Roeck   2018-12-10  379  			return 0644;
54187ff9d766b2 Guenter Roeck   2016-07-01  380  		return 0;
54187ff9d766b2 Guenter Roeck   2016-07-01  381  	default:
54187ff9d766b2 Guenter Roeck   2016-07-01  382  		return 0;
54187ff9d766b2 Guenter Roeck   2016-07-01  383  	}
54187ff9d766b2 Guenter Roeck   2016-07-01  384  }

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Václav Kubernát March 18, 2021, 9:56 a.m. UTC | #3
Hi Dan,

thanks, I will fix this in v3 of this patch series.

Vaclav

st 17. 3. 2021 v 6:14 odesílatel Dan Carpenter
<dan.carpenter@oracle.com> napsal:
>
> Hi "Václav,
>
> url:    https://github.com/0day-ci/linux/commits/V-clav-Kubern-t/hwmon-max31790-Rework-to-use-regmap/20210317-015931
> base:   https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
> config: x86_64-randconfig-m001-20210316 (attached as .config)
> compiler: gcc-9 (Debian 9.3.0-22) 9.3.0
>
> If you fix the issue, kindly add following tag as appropriate
> Reported-by: kernel test robot <lkp@intel.com>
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
>
> smatch warnings:
> drivers/hwmon/max31790.c:263 max31790_fan_is_visible() warn: impossible condition '(fan_config < 0) => (0-255 < 0)'
> drivers/hwmon/max31790.c:337 max31790_write_pwm() warn: impossible condition '(fan_config < 0) => (0-255 < 0)'
> drivers/hwmon/max31790.c:372 max31790_pwm_is_visible() warn: impossible condition '(fan_config < 0) => (0-255 < 0)'
>
> vim +263 drivers/hwmon/max31790.c
>
> 54187ff9d766b2 Guenter Roeck   2016-07-01  257  static umode_t max31790_fan_is_visible(const void *_data, u32 attr, int channel)
> 195a4b4298a795 Il Han          2015-08-30  258  {
> 54187ff9d766b2 Guenter Roeck   2016-07-01  259          const struct max31790_data *data = _data;
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  260          struct regmap *regmap = data->regmap;
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  261          u8 fan_config = read_reg_byte(regmap, MAX31790_REG_FAN_CONFIG(channel % NR_CHANNEL));
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  262
> 2c8602cfaeab63 Václav Kubernát 2021-03-16 @263          if (fan_config < 0)
>                                                             ^^^^^^^^^^^^^^
> A u8 can't be negative.
>
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  264                  return 0;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  265
> 54187ff9d766b2 Guenter Roeck   2016-07-01  266          switch (attr) {
> 54187ff9d766b2 Guenter Roeck   2016-07-01  267          case hwmon_fan_input:
> 54187ff9d766b2 Guenter Roeck   2016-07-01  268          case hwmon_fan_fault:
> 54187ff9d766b2 Guenter Roeck   2016-07-01  269                  if (channel < NR_CHANNEL ||
> 54187ff9d766b2 Guenter Roeck   2016-07-01  270                      (fan_config & MAX31790_FAN_CFG_TACH_INPUT))
> dc8dbb4d7672b7 Guenter Roeck   2018-12-10  271                          return 0444;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  272                  return 0;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  273          case hwmon_fan_target:
> 54187ff9d766b2 Guenter Roeck   2016-07-01  274                  if (channel < NR_CHANNEL &&
> 54187ff9d766b2 Guenter Roeck   2016-07-01  275                      !(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
> dc8dbb4d7672b7 Guenter Roeck   2018-12-10  276                          return 0644;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  277                  return 0;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  278          default:
> 54187ff9d766b2 Guenter Roeck   2016-07-01  279                  return 0;
> 195a4b4298a795 Il Han          2015-08-30  280          }
> 195a4b4298a795 Il Han          2015-08-30  281  }
> 195a4b4298a795 Il Han          2015-08-30  282
> 54187ff9d766b2 Guenter Roeck   2016-07-01  283  static int max31790_read_pwm(struct device *dev, u32 attr, int channel,
> 54187ff9d766b2 Guenter Roeck   2016-07-01  284                               long *val)
> 195a4b4298a795 Il Han          2015-08-30  285  {
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  286          struct max31790_data *data = dev_get_drvdata(dev);
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  287          struct regmap *regmap = data->regmap;
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  288          int read;
> 195a4b4298a795 Il Han          2015-08-30  289
> 195a4b4298a795 Il Han          2015-08-30  290          if (IS_ERR(data))
> 195a4b4298a795 Il Han          2015-08-30  291                  return PTR_ERR(data);
> 195a4b4298a795 Il Han          2015-08-30  292
> 54187ff9d766b2 Guenter Roeck   2016-07-01  293          switch (attr) {
> 54187ff9d766b2 Guenter Roeck   2016-07-01  294          case hwmon_pwm_input:
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  295                  read = read_reg_word(regmap, MAX31790_REG_PWMOUT(channel));
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  296                  if (read < 0)
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  297                          return read;
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  298
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  299                  *val = read >> 8;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  300                  return 0;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  301          case hwmon_pwm_enable:
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  302                  read = read_reg_byte(regmap, MAX31790_REG_FAN_CONFIG(channel));
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  303                  if (read < 0)
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  304                          return read;
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  305
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  306                  if (read & MAX31790_FAN_CFG_RPM_MODE)
> 54187ff9d766b2 Guenter Roeck   2016-07-01  307                          *val = 2;
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  308                  else if (read & MAX31790_FAN_CFG_TACH_INPUT_EN)
> 54187ff9d766b2 Guenter Roeck   2016-07-01  309                          *val = 1;
> 195a4b4298a795 Il Han          2015-08-30  310                  else
> 54187ff9d766b2 Guenter Roeck   2016-07-01  311                          *val = 0;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  312                  return 0;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  313          default:
> 54187ff9d766b2 Guenter Roeck   2016-07-01  314                  return -EOPNOTSUPP;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  315          }
> 195a4b4298a795 Il Han          2015-08-30  316  }
> 195a4b4298a795 Il Han          2015-08-30  317
> 54187ff9d766b2 Guenter Roeck   2016-07-01  318  static int max31790_write_pwm(struct device *dev, u32 attr, int channel,
> 54187ff9d766b2 Guenter Roeck   2016-07-01  319                                long val)
> 195a4b4298a795 Il Han          2015-08-30  320  {
> 195a4b4298a795 Il Han          2015-08-30  321          struct max31790_data *data = dev_get_drvdata(dev);
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  322          struct regmap *regmap = data->regmap;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  323          u8 fan_config;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  324          int err = 0;
> 195a4b4298a795 Il Han          2015-08-30  325
> 54187ff9d766b2 Guenter Roeck   2016-07-01  326          switch (attr) {
> 54187ff9d766b2 Guenter Roeck   2016-07-01  327          case hwmon_pwm_input:
> 54187ff9d766b2 Guenter Roeck   2016-07-01  328                  if (val < 0 || val > 255) {
> 54187ff9d766b2 Guenter Roeck   2016-07-01  329                          err = -EINVAL;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  330                          break;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  331                  }
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  332                  err = write_reg_word(regmap, MAX31790_REG_PWMOUT(channel), val << 8);
> 195a4b4298a795 Il Han          2015-08-30  333                  break;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  334          case hwmon_pwm_enable:
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  335                  fan_config = read_reg_byte(regmap, MAX31790_REG_FAN_CONFIG(channel % NR_CHANNEL));
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  336
> 2c8602cfaeab63 Václav Kubernát 2021-03-16 @337                  if (fan_config < 0)
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  338                          return fan_config;
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  339
> 54187ff9d766b2 Guenter Roeck   2016-07-01  340                  if (val == 0) {
> 54187ff9d766b2 Guenter Roeck   2016-07-01  341                          fan_config &= ~(MAX31790_FAN_CFG_TACH_INPUT_EN |
> 54187ff9d766b2 Guenter Roeck   2016-07-01  342                                          MAX31790_FAN_CFG_RPM_MODE);
> 54187ff9d766b2 Guenter Roeck   2016-07-01  343                  } else if (val == 1) {
> 54187ff9d766b2 Guenter Roeck   2016-07-01  344                          fan_config = (fan_config |
> 54187ff9d766b2 Guenter Roeck   2016-07-01  345                                        MAX31790_FAN_CFG_TACH_INPUT_EN) &
> 54187ff9d766b2 Guenter Roeck   2016-07-01  346                                       ~MAX31790_FAN_CFG_RPM_MODE;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  347                  } else if (val == 2) {
> 54187ff9d766b2 Guenter Roeck   2016-07-01  348                          fan_config |= MAX31790_FAN_CFG_TACH_INPUT_EN |
> 54187ff9d766b2 Guenter Roeck   2016-07-01  349                                        MAX31790_FAN_CFG_RPM_MODE;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  350                  } else {
> 54187ff9d766b2 Guenter Roeck   2016-07-01  351                          err = -EINVAL;
> 195a4b4298a795 Il Han          2015-08-30  352                          break;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  353                  }
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  354                  err = regmap_write(regmap,
> 54187ff9d766b2 Guenter Roeck   2016-07-01  355                                     MAX31790_REG_FAN_CONFIG(channel),
> 54187ff9d766b2 Guenter Roeck   2016-07-01  356                                     fan_config);
> 195a4b4298a795 Il Han          2015-08-30  357                  break;
> 195a4b4298a795 Il Han          2015-08-30  358          default:
> 54187ff9d766b2 Guenter Roeck   2016-07-01  359                  err = -EOPNOTSUPP;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  360                  break;
> 195a4b4298a795 Il Han          2015-08-30  361          }
> 195a4b4298a795 Il Han          2015-08-30  362
> 195a4b4298a795 Il Han          2015-08-30  363          return err;
> 195a4b4298a795 Il Han          2015-08-30  364  }
> 195a4b4298a795 Il Han          2015-08-30  365
> 54187ff9d766b2 Guenter Roeck   2016-07-01  366  static umode_t max31790_pwm_is_visible(const void *_data, u32 attr, int channel)
> 195a4b4298a795 Il Han          2015-08-30  367  {
> 54187ff9d766b2 Guenter Roeck   2016-07-01  368          const struct max31790_data *data = _data;
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  369          struct regmap *regmap = data->regmap;
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  370          u8 fan_config = read_reg_byte(regmap, MAX31790_REG_FAN_CONFIG(channel % NR_CHANNEL));
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  371
> 2c8602cfaeab63 Václav Kubernát 2021-03-16 @372          if (fan_config < 0)
> 2c8602cfaeab63 Václav Kubernát 2021-03-16  373                  return 0;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  374
> 54187ff9d766b2 Guenter Roeck   2016-07-01  375          switch (attr) {
> 54187ff9d766b2 Guenter Roeck   2016-07-01  376          case hwmon_pwm_input:
> 54187ff9d766b2 Guenter Roeck   2016-07-01  377          case hwmon_pwm_enable:
> 54187ff9d766b2 Guenter Roeck   2016-07-01  378                  if (!(fan_config & MAX31790_FAN_CFG_TACH_INPUT))
> dc8dbb4d7672b7 Guenter Roeck   2018-12-10  379                          return 0644;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  380                  return 0;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  381          default:
> 54187ff9d766b2 Guenter Roeck   2016-07-01  382                  return 0;
> 54187ff9d766b2 Guenter Roeck   2016-07-01  383          }
> 54187ff9d766b2 Guenter Roeck   2016-07-01  384  }
>
> ---
> 0-DAY CI Kernel Test Service, Intel Corporation
> https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org
Václav Kubernát March 30, 2021, 3:43 a.m. UTC | #4
Hi Guenter,

Thank you for the comments. I will fix the issues in a V3 patch.

About the mutex: I was looking at regmap and saw it did locking by
itself. But I suppose writing still has to be locked, because the
write function writes more than once. I will add the mutex back.

Václav

út 30. 3. 2021 v 0:27 odesílatel Guenter Roeck <linux@roeck-us.net> napsal:
>
> On Tue, Mar 16, 2021 at 06:54:58PM +0100, Václav Kubernát wrote:
> > 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>
>
> Comments are in addition to comments from Dan and 0-day.
>
> > ---
> >  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);
> > +
>
> lease no empty line between assignment and check.
>
> > +     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);
>
> Now unnecessary.
>
> >
> >       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;
>
>                 *val = RPM_FROM_REG(tach, get_tach_period(dynamics));
>
> >               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;
>
>                 *val = RPM_FROM_REG(tach, get_tach_period(dynamics));
>
> >               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));
> > +
> Unnecessary empty line.
>
> > +             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);
> > -
> Why is this lock no longer required ? There are still multiple writes
> when writing hwmon_fan_target.
>
> >       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;
>
> fan_config needs to be int. Also, this is a poor way of handling
> this problem. Since fan_config does not change dynamically,
> this is one set of values that would make sense to keep cached
> locally.
>
> >
> >       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);
>
> Now unnecessary.
>
> >
> > -     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);
> > -
> Are you sure this mutex is no longer needed here, ie that there
> can not be an interaction with multiple writes from multiple processes
> at the same time ?
>
> >       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;
>
> int problem again.
>
> >
> >       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;
>
> The above "cached" values are static, and it did make sense to keep those
> locally to avoid requiring unnecessary error handling (and to detect issues
> with the chip early).
>
> > -     }
> > -
> > -     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,

út 30. 3. 2021 v 0:27 odesílatel Guenter Roeck <linux@roeck-us.net> napsal:
>
> On Tue, Mar 16, 2021 at 06:54:58PM +0100, Václav Kubernát wrote:
> > 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>
>
> Comments are in addition to comments from Dan and 0-day.
>
> > ---
> >  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);
> > +
>
> lease no empty line between assignment and check.
>
> > +     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);
>
> Now unnecessary.
>
> >
> >       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;
>
>                 *val = RPM_FROM_REG(tach, get_tach_period(dynamics));
>
> >               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;
>
>                 *val = RPM_FROM_REG(tach, get_tach_period(dynamics));
>
> >               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));
> > +
> Unnecessary empty line.
>
> > +             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);
> > -
> Why is this lock no longer required ? There are still multiple writes
> when writing hwmon_fan_target.
>
> >       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;
>
> fan_config needs to be int. Also, this is a poor way of handling
> this problem. Since fan_config does not change dynamically,
> this is one set of values that would make sense to keep cached
> locally.
>
> >
> >       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);
>
> Now unnecessary.
>
> >
> > -     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);
> > -
> Are you sure this mutex is no longer needed here, ie that there
> can not be an interaction with multiple writes from multiple processes
> at the same time ?
>
> >       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;
>
> int problem again.
>
> >
> >       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;
>
> The above "cached" values are static, and it did make sense to keep those
> locally to avoid requiring unnecessary error handling (and to detect issues
> with the chip early).
>
> > -     }
> > -
> > -     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,
diff mbox series

Patch

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,