Messages in this thread | | | Subject | Re: [PATCH v2 3/5] misc: eeprom_93xx46: Implement eeprom_93xx46 DT bindings. | From | "Andrew F. Davis" <> | Date | Thu, 19 Nov 2015 08:00:07 -0600 |
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On 11/18/2015 11:50 PM, Vladimir Zapolskiy wrote: > Hi Cory, > > On 19.11.2015 05:29, Cory Tusar wrote: >> This commit implements bindings in the eeprom_93xx46 driver allowing >> device word size and read-only attributes to be specified via >> devicetree. >> >> Signed-off-by: Cory Tusar <cory.tusar@pid1solutions.com> >> --- >> drivers/misc/eeprom/eeprom_93xx46.c | 62 +++++++++++++++++++++++++++++++++++++ >> 1 file changed, 62 insertions(+) >> >> diff --git a/drivers/misc/eeprom/eeprom_93xx46.c b/drivers/misc/eeprom/eeprom_93xx46.c >> index e1bf0a5..1f29d9a 100644 >> --- a/drivers/misc/eeprom/eeprom_93xx46.c >> +++ b/drivers/misc/eeprom/eeprom_93xx46.c >> @@ -13,6 +13,8 @@ >> #include <linux/kernel.h> >> #include <linux/module.h> >> #include <linux/mutex.h> >> +#include <linux/of.h> >> +#include <linux/of_device.h> >> #include <linux/slab.h> >> #include <linux/spi/spi.h> >> #include <linux/sysfs.h> >> @@ -294,12 +296,71 @@ static ssize_t eeprom_93xx46_store_erase(struct device *dev, >> } >> static DEVICE_ATTR(erase, S_IWUSR, NULL, eeprom_93xx46_store_erase); >> >> +#ifdef CONFIG_OF >> +static const struct of_device_id eeprom_93xx46_of_table[] = { >> + { .compatible = "eeprom-93xx46", }, >> + {} >> +}; >> +MODULE_DEVICE_TABLE(of, eeprom_93xx46_of_table); >> + > > Please move this declaration closer to struct spi_driver > eeprom_93xx46_driver below. >
It is referenced in the function below.
> Also you can avoid #ifdef here, if you write > > .of_match_table = of_match_ptr(eeprom_93xx46_of_table) >
I think this is backwards, when eeprom_93xx46_of_table is #ifdef'd off you need to use of_match_ptr so when CONFIG_OF is not defined you wont get an undefined reference to eeprom_93xx46_of_table.
Without the #ifdef, eeprom_93xx46_of_table will always be defined and you can just .of_match_table = eeprom_93xx46_of_table; safely.
> Whenever possible please avoid #ifdef's in .c files. > >> +static int eeprom_93xx46_probe_dt(struct spi_device *spi) >> +{ >> + struct device_node *np = spi->dev.of_node; >> + struct eeprom_93xx46_platform_data *pd; >> + u32 tmp; >> + int ret; >> + >> + if (!of_match_device(eeprom_93xx46_of_table, &spi->dev)) >> + return 0; >> + >> + pd = devm_kzalloc(&spi->dev, sizeof(*pd), GFP_KERNEL); >> + if (!pd) >> + return -ENOMEM; >> + >> + ret = of_property_read_u32(np, "data-size", &tmp); >> + if (ret < 0) { >> + dev_err(&spi->dev, "data-size property not found\n"); >> + goto error_free; > > Because you use devm_* resource allocation in .probe, just return error. > > Plus I would suggest to change "data-size" property to an optional one, > here I mean that if it is omitted, then by default consider pd->flags |= > EE_ADDR8. > >> + } >> + >> + if (tmp == 8) { >> + pd->flags |= EE_ADDR8; >> + } else if (tmp == 16) { >> + pd->flags |= EE_ADDR16; >> + } else { >> + dev_err(&spi->dev, "invalid data-size (%d)\n", tmp); >> + goto error_free; > > Same here. > >> + } >> + >> + if (of_property_read_bool(np, "read-only")) >> + pd->flags |= EE_READONLY; >> + >> + spi->dev.platform_data = pd; >> + >> + return 1; > > On success please return 0. > >> +error_free: >> + devm_kfree(&spi->dev, pd); >> + return ret; >> +} >> + >> +#else >> +static inline int eeprom_93xx46_probe_dt(struct spi_device *spi) >> +{ >> + return 0; >> +} >> +#endif >> + > > I actually don't see a point to have #ifdef CONFIG_OF here. >
Usually to avoid a lot of dead code and data when OF is not enabled.
> Instead please add a check for !spi->dev.of_node at the beginning of > eeprom_93xx46_probe_dt() or in .probe() > >> static int eeprom_93xx46_probe(struct spi_device *spi) >> { >> struct eeprom_93xx46_platform_data *pd; >> struct eeprom_93xx46_dev *edev; >> int err; >> >> + err = eeprom_93xx46_probe_dt(spi); >> + if (err < 0) >> + return err; >> + >> pd = spi->dev.platform_data; >> if (!pd) { >> dev_err(&spi->dev, "missing platform data\n"); >> @@ -370,6 +431,7 @@ static int eeprom_93xx46_remove(struct spi_device *spi) >> static struct spi_driver eeprom_93xx46_driver = { >> .driver = { >> .name = "93xx46", >> + .of_match_table = eeprom_93xx46_of_table, >> }, >> .probe = eeprom_93xx46_probe, >> .remove = eeprom_93xx46_remove, >>
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