[RFC 1/3] drivers/hwmon/pmbus: Access word data for STATUS_WORD and use it by default
From: "Edward A. James" Pmbus core always reads byte data from the status register, even if configured to use STATUS_WORD. Use a function pointer so we always do either byte or word access depending on which register we're trying to access. Also switch to use STATUS_WORD by default. Signed-off-by: Edward A. James --- drivers/hwmon/pmbus/pmbus_core.c | 69 +++- 1 file changed, 54 insertions(+), 15 deletions(-) diff --git a/drivers/hwmon/pmbus/pmbus_core.c b/drivers/hwmon/pmbus/pmbus_core.c index f1eff6b..8511aba 100644 --- a/drivers/hwmon/pmbus/pmbus_core.c +++ b/drivers/hwmon/pmbus/pmbus_core.c @@ -113,7 +113,8 @@ struct pmbus_data { * so we keep them all together. */ u8 status[PB_NUM_STATUS_REG]; - u8 status_register; + + int (*read_status)(struct i2c_client *client, int page); u8 currpage; }; @@ -324,7 +325,7 @@ static int pmbus_check_status_cml(struct i2c_client *client) struct pmbus_data *data = i2c_get_clientdata(client); int status, status2; - status = _pmbus_read_byte_data(client, -1, data->status_register); + status = data->read_status(client, -1); if (status < 0 || (status & PB_STATUS_CML)) { status2 = _pmbus_read_byte_data(client, -1, PMBUS_STATUS_CML); if (status2 < 0 || (status2 & PB_CML_FAULT_INVALID_COMMAND)) @@ -348,6 +349,36 @@ static bool pmbus_check_register(struct i2c_client *client, return rv >= 0; } +/* Check specified page status register accessibility. Need a separate + * function rather than the two above so we can use the correct status + * register, and we can optimize out the second status register read. + */ +static bool pmbus_check_status_register(struct i2c_client *client, int page) +{ + int status, rc = 0; + struct pmbus_data *data = i2c_get_clientdata(client); + + status = data->read_status(client, page); + if (status < 0) + goto out; + + if (!(data->flags & PMBUS_SKIP_STATUS_CHECK)) { + if (status & PB_STATUS_CML) { + status = _pmbus_read_byte_data(client, -1, + PMBUS_STATUS_CML); + if (status < 0 || + (status & PB_CML_FAULT_INVALID_COMMAND)) + goto out; + } + } + + rc = 1; + +out: + pmbus_clear_fault_page(client, -1); + return rc; +} + bool pmbus_check_byte_register(struct i2c_client *client, int page, int reg) { return pmbus_check_register(client, _pmbus_read_byte_data, page, reg); @@ -393,9 +424,8 @@ static struct pmbus_data *pmbus_update_device(struct device *dev) int i, j; for (i = 0; i < info->pages; i++) { - data->status[PB_STATUS_BASE + i] - = _pmbus_read_byte_data(client, i, - data->status_register); + data->status[PB_STATUS_BASE + i] = + data->read_status(client, i); for (j = 0; j < ARRAY_SIZE(pmbus_status); j++) { struct _pmbus_status *s = &pmbus_status[j]; @@ -1051,8 +1081,7 @@ static int pmbus_add_sensor_attrs_one(struct i2c_client *client, * the generic status register for this page is accessible. */ if (!ret && attr->gbit && - pmbus_check_byte_register(client, page, - data->status_register)) { + pmbus_check_status_register(client, page)) { ret = pmbus_add_boolean(data, name, "alarm", index, NULL, NULL, PB_STATUS_BASE + page, @@ -1729,6 +1758,16 @@ static int pmbus_identify_common(struct i2c_client *client, return 0; } +static int pmbus_read_status_word(struct i2c_client *client, int page) +{ + return _pmbus_read_word_data(client, page, PMBUS_STATUS_WORD); +} + +static int pmbus_read_status_byte(struct i2c_client *client, int page) +{ + return _pmbus_read_byte_data(client, page, PMBUS_STATUS_BYTE); +} + static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data, struct pmbus_driver_info *info) { @@ -1736,16 +1775,16 @@ static int pmbus_init_common(struct i2c_client *client, struct pmbus_data *data, int page, ret; /* -* Some PMBus chips don't support PMBUS_STATUS_BYTE, so try -* to use PMBUS_STATUS_WORD instead if that is the case. +* Some PMBus chips don't support PMBUS_STATUS_WORD, so try +* to use PMBUS_STATUS_BYTE instead if that is the case. * Bail out if both registers are not supported. */ - data->
Re: [RFC, 1/3] drivers/hwmon/pmbus: Access word data for STATUS_WORD and use it by default
On Mon, Aug 07, 2017 at 10:25:46PM -0500, eaja...@linux.vnet.ibm.com wrote: > From: "Edward A. James" > > Pmbus core always reads byte data from the status register, even if > configured to use STATUS_WORD. Use a function pointer so we always do > either byte or word access depending on which register we're trying to > access. Also switch to use STATUS_WORD by default. > > Signed-off-by: Edward A. James > --- > drivers/hwmon/pmbus/pmbus_core.c | 69 > +++- > 1 file changed, 54 insertions(+), 15 deletions(-) > > diff --git a/drivers/hwmon/pmbus/pmbus_core.c > b/drivers/hwmon/pmbus/pmbus_core.c > index f1eff6b..8511aba 100644 > --- a/drivers/hwmon/pmbus/pmbus_core.c > +++ b/drivers/hwmon/pmbus/pmbus_core.c > @@ -113,7 +113,8 @@ struct pmbus_data { >* so we keep them all together. >*/ > u8 status[PB_NUM_STATUS_REG]; > - u8 status_register; > + > + int (*read_status)(struct i2c_client *client, int page); > > u8 currpage; > }; > @@ -324,7 +325,7 @@ static int pmbus_check_status_cml(struct i2c_client > *client) > struct pmbus_data *data = i2c_get_clientdata(client); > int status, status2; > > - status = _pmbus_read_byte_data(client, -1, data->status_register); > + status = data->read_status(client, -1); > if (status < 0 || (status & PB_STATUS_CML)) { > status2 = _pmbus_read_byte_data(client, -1, PMBUS_STATUS_CML); > if (status2 < 0 || (status2 & PB_CML_FAULT_INVALID_COMMAND)) > @@ -348,6 +349,36 @@ static bool pmbus_check_register(struct i2c_client > *client, > return rv >= 0; > } > > +/* Check specified page status register accessibility. Need a separate I am not in favor of networking-style multi-line comments. > + * function rather than the two above so we can use the correct status > + * register, and we can optimize out the second status register read. > + */ > +static bool pmbus_check_status_register(struct i2c_client *client, int page) > +{ > + int status, rc = 0; > + struct pmbus_data *data = i2c_get_clientdata(client); > + > + status = data->read_status(client, page); > + if (status < 0) > + goto out; > + > + if (!(data->flags & PMBUS_SKIP_STATUS_CHECK)) { > + if (status & PB_STATUS_CML) { > + status = _pmbus_read_byte_data(client, -1, > +PMBUS_STATUS_CML); > + if (status < 0 || > + (status & PB_CML_FAULT_INVALID_COMMAND)) > + goto out; > + } > + } > + > + rc = 1; If you want to use bool, please use bool. > + > +out: > + pmbus_clear_fault_page(client, -1); > + return rc; > +} > + > bool pmbus_check_byte_register(struct i2c_client *client, int page, int reg) > { > return pmbus_check_register(client, _pmbus_read_byte_data, page, reg); > @@ -393,9 +424,8 @@ static struct pmbus_data *pmbus_update_device(struct > device *dev) > int i, j; > > for (i = 0; i < info->pages; i++) { > - data->status[PB_STATUS_BASE + i] > - = _pmbus_read_byte_data(client, i, > - data->status_register); > + data->status[PB_STATUS_BASE + i] = > + data->read_status(client, i); This doesn't really work anymore, since the status register now has to hold 16 bit. Sure, the next patch tries to fix that, but that leaves a 1-patch gap. Changing the width of data->status to 16 bit results in a "waste" of a whopping 32 * 6 + 2 or around 200 bytes. I don't think that warrants the complexity you are introducing with the next patch. Are you sure that adds less than 200 bytes of code ?) > for (j = 0; j < ARRAY_SIZE(pmbus_status); j++) { > struct _pmbus_status *s = &pmbus_status[j]; > > @@ -1051,8 +1081,7 @@ static int pmbus_add_sensor_attrs_one(struct i2c_client > *client, >* the generic status register for this page is accessible. >*/ > if (!ret && attr->gbit && > - pmbus_check_byte_register(client, page, > - data->status_register)) { > + pmbus_check_status_register(client, page)) { > ret = pmbus_add_boolean(data, name, "alarm", index, > NULL, NULL, > PB_STATUS_BASE + page, > @@ -1729,6 +1758,16 @@ static int pmbus_identify_common(struct i2c_client > *client, > return 0; > } > > +static int pmbus_read_status_word(struct i2c_client *client, int page) > +{ > + return _pmbus_read_word_data(client, page, PMBUS_STATUS_WORD); > +} > + > +static int pmbus_read_status_byte(struct i2c_client *client, int page) > +{ >