| Message ID | 20210318092406.5340-3-michael@walle.cc |
|---|---|
| State | Superseded |
| Delegated to: | Ambarus Tudor |
| Headers | show |
| Series | mtd: spi-nor: support dumping sfdp tables | expand |
On 2021/3/18 17:24, Michael Walle wrote: > Add support to show the name and JEDEC identifier as well as to dump the > SFDP table. Not all flashes list their SFDP table contents in their > datasheet. So having that is useful. It might also be helpful in bug > reports from users. > > The idea behind the sysfs module is also to have raw access to the SPI > NOR flash device registers, which can also be useful for debugging. Hi Michael, I like the idea to dump the sfdp data,it will make debug easier. should it go in debugfs? we already have debugfs files for partname and partid of the flash. > > Signed-off-by: Michael Walle <michael@walle.cc> > --- > drivers/mtd/spi-nor/Makefile | 2 +- > drivers/mtd/spi-nor/core.c | 5 +++ > drivers/mtd/spi-nor/core.h | 3 ++ > drivers/mtd/spi-nor/sysfs.c | 86 ++++++++++++++++++++++++++++++++++++ > 4 files changed, 95 insertions(+), 1 deletion(-) > create mode 100644 drivers/mtd/spi-nor/sysfs.c > > diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile > index 653923896205..aff308f75987 100644 > --- a/drivers/mtd/spi-nor/Makefile > +++ b/drivers/mtd/spi-nor/Makefile > @@ -1,6 +1,6 @@ > # SPDX-License-Identifier: GPL-2.0 > > -spi-nor-objs := core.o sfdp.o > +spi-nor-objs := core.o sfdp.o sysfs.o > spi-nor-objs += atmel.o > spi-nor-objs += catalyst.o > spi-nor-objs += eon.o > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c > index 4a315cb1c4db..2eaf4ba8c0f3 100644 > --- a/drivers/mtd/spi-nor/core.c > +++ b/drivers/mtd/spi-nor/core.c > @@ -3707,6 +3707,10 @@ static int spi_nor_probe(struct spi_mem *spimem) > if (ret) > return ret; > > + ret = spi_nor_sysfs_create(nor); > + if (ret) > + return ret; > + > return mtd_device_register(&nor->mtd, data ? data->parts : NULL, > data ? data->nr_parts : 0); > } > @@ -3716,6 +3720,7 @@ static int spi_nor_remove(struct spi_mem *spimem) > struct spi_nor *nor = spi_mem_get_drvdata(spimem); > > spi_nor_restore(nor); > + spi_nor_sysfs_remove(nor); > > /* Clean up MTD stuff. */ > return mtd_device_unregister(&nor->mtd); > diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h > index 668f22011b1d..dd592f7b62d1 100644 > --- a/drivers/mtd/spi-nor/core.h > +++ b/drivers/mtd/spi-nor/core.h > @@ -488,4 +488,7 @@ static struct spi_nor __maybe_unused *mtd_to_spi_nor(struct mtd_info *mtd) > return mtd->priv; > } > > +int spi_nor_sysfs_create(struct spi_nor *nor); > +void spi_nor_sysfs_remove(struct spi_nor *nor); > + > #endif /* __LINUX_MTD_SPI_NOR_INTERNAL_H */ > diff --git a/drivers/mtd/spi-nor/sysfs.c b/drivers/mtd/spi-nor/sysfs.c > new file mode 100644 > index 000000000000..0de031e246c5 > --- /dev/null > +++ b/drivers/mtd/spi-nor/sysfs.c > @@ -0,0 +1,86 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +#include <linux/mtd/spi-nor.h> > +#include <linux/spi/spi.h> > +#include <linux/spi/spi-mem.h> > +#include <linux/sysfs.h> > + > +#include "core.h" > + > +static ssize_t name_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct spi_device *spi = to_spi_device(dev); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + > + return sprintf(buf, "%s\n", nor->info->name); perhaps sysfs_emit() instead if we go sysfs? as suggested by [1]. [1] Documentation/filesystems/sysfs.rst:line 246 Thanks, Yicong > +} > +static DEVICE_ATTR_RO(name); > + > +static ssize_t jedec_id_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct spi_device *spi = to_spi_device(dev); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + > + return sprintf(buf, "%*phN\n", nor->info->id_len, nor->info->id); > +} > +static DEVICE_ATTR_RO(jedec_id); > + > +static struct attribute *spi_nor_sysfs_entries[] = { > + &dev_attr_name.attr, > + &dev_attr_jedec_id.attr, > + NULL > +}; > + > +static ssize_t sfdp_read(struct file *filp, struct kobject *kobj, > + struct bin_attribute *bin_attr, char *buf, > + loff_t off, size_t count) > +{ > + struct spi_device *spi = to_spi_device(kobj_to_dev(kobj)); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + struct sfdp *sfdp = nor->sfdp; > + size_t sfdp_size = sfdp->num_dwords * sizeof(*sfdp->dwords); > + > + return memory_read_from_buffer(buf, count, &off, nor->sfdp->dwords, > + sfdp_size); > +} > +static BIN_ATTR_RO(sfdp, PAGE_SIZE); > + > +static struct bin_attribute *spi_nor_sysfs_bin_entries[] = { > + &bin_attr_sfdp, > + NULL > +}; > + > +static umode_t spi_nor_sysfs_is_bin_visible(struct kobject *kobj, > + struct bin_attribute *attr, int n) > +{ > + struct spi_device *spi = to_spi_device(kobj_to_dev(kobj)); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + > + if (attr == &bin_attr_sfdp && nor->sfdp) > + return 0444; > + > + return 0; > +} > + > +static struct attribute_group spi_nor_sysfs_attr_group = { > + .name = NULL, > + .is_bin_visible = spi_nor_sysfs_is_bin_visible, > + .attrs = spi_nor_sysfs_entries, > + .bin_attrs = spi_nor_sysfs_bin_entries, > +}; > + > +int spi_nor_sysfs_create(struct spi_nor *nor) > +{ > + return sysfs_create_group(&nor->dev->kobj, &spi_nor_sysfs_attr_group); > +} > + > +void spi_nor_sysfs_remove(struct spi_nor *nor) > +{ > + sysfs_remove_group(&nor->dev->kobj, &spi_nor_sysfs_attr_group); > +} >
Hi Yicong, Am 2021-03-20 05:16, schrieb Yicong Yang: > On 2021/3/18 17:24, Michael Walle wrote: >> Add support to show the name and JEDEC identifier as well as to dump >> the >> SFDP table. Not all flashes list their SFDP table contents in their >> datasheet. So having that is useful. It might also be helpful in bug >> reports from users. >> >> The idea behind the sysfs module is also to have raw access to the SPI >> NOR flash device registers, which can also be useful for debugging. > > I like the idea to dump the sfdp data,it will make debug easier. > should it go in debugfs? > we already have debugfs files for partname and partid of the flash. I've seen that, but thats for the MTD subsystem and is per MTD. Well, one could add an own debugfs for spi-nor, but I still fear it might not be available just when its needed. Of course a developer can easily enable it for its debugging kernel. But I'm not sure if thats the only use case. I'd guess it boils down to, whether there could also be tooling around this. Eg. think of something like "lssfdp". I'd prefer sysfs, but lets hear what the maintainers think. [..] >> +static ssize_t name_show(struct device *dev, >> + struct device_attribute *attr, char *buf) >> +{ >> + struct spi_device *spi = to_spi_device(dev); >> + struct spi_mem *spimem = spi_get_drvdata(spi); >> + struct spi_nor *nor = spi_mem_get_drvdata(spimem); >> + >> + return sprintf(buf, "%s\n", nor->info->name); > > perhaps sysfs_emit() instead if we go sysfs? as suggested by [1]. Thanks, didn't know about that new helper. -michael
Hi Michael, I have not worked with sysfs much so only giving this patch a quick overview. On 18/03/21 10:24AM, Michael Walle wrote: > Add support to show the name and JEDEC identifier as well as to dump the > SFDP table. Not all flashes list their SFDP table contents in their > datasheet. So having that is useful. It might also be helpful in bug > reports from users. > > The idea behind the sysfs module is also to have raw access to the SPI > NOR flash device registers, which can also be useful for debugging. Your current patch does not add this feature. Why do you think it is important enough to mention it? > > Signed-off-by: Michael Walle <michael@walle.cc> > --- > drivers/mtd/spi-nor/Makefile | 2 +- > drivers/mtd/spi-nor/core.c | 5 +++ > drivers/mtd/spi-nor/core.h | 3 ++ > drivers/mtd/spi-nor/sysfs.c | 86 ++++++++++++++++++++++++++++++++++++ > 4 files changed, 95 insertions(+), 1 deletion(-) > create mode 100644 drivers/mtd/spi-nor/sysfs.c > > diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile > index 653923896205..aff308f75987 100644 > --- a/drivers/mtd/spi-nor/Makefile > +++ b/drivers/mtd/spi-nor/Makefile > @@ -1,6 +1,6 @@ > # SPDX-License-Identifier: GPL-2.0 > > -spi-nor-objs := core.o sfdp.o > +spi-nor-objs := core.o sfdp.o sysfs.o > spi-nor-objs += atmel.o > spi-nor-objs += catalyst.o > spi-nor-objs += eon.o > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c > index 4a315cb1c4db..2eaf4ba8c0f3 100644 > --- a/drivers/mtd/spi-nor/core.c > +++ b/drivers/mtd/spi-nor/core.c > @@ -3707,6 +3707,10 @@ static int spi_nor_probe(struct spi_mem *spimem) > if (ret) > return ret; > > + ret = spi_nor_sysfs_create(nor); > + if (ret) > + return ret; > + > return mtd_device_register(&nor->mtd, data ? data->parts : NULL, > data ? data->nr_parts : 0); > } > @@ -3716,6 +3720,7 @@ static int spi_nor_remove(struct spi_mem *spimem) > struct spi_nor *nor = spi_mem_get_drvdata(spimem); > > spi_nor_restore(nor); > + spi_nor_sysfs_remove(nor); > > /* Clean up MTD stuff. */ > return mtd_device_unregister(&nor->mtd); > diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h > index 668f22011b1d..dd592f7b62d1 100644 > --- a/drivers/mtd/spi-nor/core.h > +++ b/drivers/mtd/spi-nor/core.h > @@ -488,4 +488,7 @@ static struct spi_nor __maybe_unused *mtd_to_spi_nor(struct mtd_info *mtd) > return mtd->priv; > } > > +int spi_nor_sysfs_create(struct spi_nor *nor); > +void spi_nor_sysfs_remove(struct spi_nor *nor); > + > #endif /* __LINUX_MTD_SPI_NOR_INTERNAL_H */ > diff --git a/drivers/mtd/spi-nor/sysfs.c b/drivers/mtd/spi-nor/sysfs.c > new file mode 100644 > index 000000000000..0de031e246c5 > --- /dev/null > +++ b/drivers/mtd/spi-nor/sysfs.c > @@ -0,0 +1,86 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +#include <linux/mtd/spi-nor.h> > +#include <linux/spi/spi.h> > +#include <linux/spi/spi-mem.h> > +#include <linux/sysfs.h> > + > +#include "core.h" > + > +static ssize_t name_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct spi_device *spi = to_spi_device(dev); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + > + return sprintf(buf, "%s\n", nor->info->name); > +} > +static DEVICE_ATTR_RO(name); > + > +static ssize_t jedec_id_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct spi_device *spi = to_spi_device(dev); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + > + return sprintf(buf, "%*phN\n", nor->info->id_len, nor->info->id); > +} > +static DEVICE_ATTR_RO(jedec_id); > + > +static struct attribute *spi_nor_sysfs_entries[] = { > + &dev_attr_name.attr, > + &dev_attr_jedec_id.attr, > + NULL > +}; > + > +static ssize_t sfdp_read(struct file *filp, struct kobject *kobj, > + struct bin_attribute *bin_attr, char *buf, > + loff_t off, size_t count) > +{ > + struct spi_device *spi = to_spi_device(kobj_to_dev(kobj)); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + struct sfdp *sfdp = nor->sfdp; > + size_t sfdp_size = sfdp->num_dwords * sizeof(*sfdp->dwords); Is a NULL check needed here? If the flash does not have a SFDP table nor->sfdp will be NULL. > + > + return memory_read_from_buffer(buf, count, &off, nor->sfdp->dwords, > + sfdp_size); > +} > +static BIN_ATTR_RO(sfdp, PAGE_SIZE); > + > +static struct bin_attribute *spi_nor_sysfs_bin_entries[] = { > + &bin_attr_sfdp, > + NULL > +}; > + > +static umode_t spi_nor_sysfs_is_bin_visible(struct kobject *kobj, > + struct bin_attribute *attr, int n) > +{ > + struct spi_device *spi = to_spi_device(kobj_to_dev(kobj)); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + > + if (attr == &bin_attr_sfdp && nor->sfdp) > + return 0444; > + > + return 0; > +} > + > +static struct attribute_group spi_nor_sysfs_attr_group = { > + .name = NULL, > + .is_bin_visible = spi_nor_sysfs_is_bin_visible, > + .attrs = spi_nor_sysfs_entries, > + .bin_attrs = spi_nor_sysfs_bin_entries, > +}; > + > +int spi_nor_sysfs_create(struct spi_nor *nor) > +{ > + return sysfs_create_group(&nor->dev->kobj, &spi_nor_sysfs_attr_group); > +} > + > +void spi_nor_sysfs_remove(struct spi_nor *nor) > +{ > + sysfs_remove_group(&nor->dev->kobj, &spi_nor_sysfs_attr_group); > +} > -- > 2.20.1 > Rest of it looks good to me.
Hi Pratyush, Am 2021-03-22 15:43, schrieb Pratyush Yadav: > I have not worked with sysfs much so only giving this patch a quick > overview. > > On 18/03/21 10:24AM, Michael Walle wrote: >> Add support to show the name and JEDEC identifier as well as to dump >> the >> SFDP table. Not all flashes list their SFDP table contents in their >> datasheet. So having that is useful. It might also be helpful in bug >> reports from users. >> >> The idea behind the sysfs module is also to have raw access to the SPI >> NOR flash device registers, which can also be useful for debugging. > > Your current patch does not add this feature. Why do you think it is > important enough to mention it? It was part of my first (not submitted) version. I.e. you could also read the status register(s). Comes in handy for debugging the locking code, for example. I can also remove that paragraph ;) >> Signed-off-by: Michael Walle <michael@walle.cc> >> --- >> drivers/mtd/spi-nor/Makefile | 2 +- >> drivers/mtd/spi-nor/core.c | 5 +++ >> drivers/mtd/spi-nor/core.h | 3 ++ >> drivers/mtd/spi-nor/sysfs.c | 86 >> ++++++++++++++++++++++++++++++++++++ >> 4 files changed, 95 insertions(+), 1 deletion(-) >> create mode 100644 drivers/mtd/spi-nor/sysfs.c >> >> diff --git a/drivers/mtd/spi-nor/Makefile >> b/drivers/mtd/spi-nor/Makefile >> index 653923896205..aff308f75987 100644 >> --- a/drivers/mtd/spi-nor/Makefile >> +++ b/drivers/mtd/spi-nor/Makefile >> @@ -1,6 +1,6 @@ >> # SPDX-License-Identifier: GPL-2.0 >> >> -spi-nor-objs := core.o sfdp.o >> +spi-nor-objs := core.o sfdp.o sysfs.o >> spi-nor-objs += atmel.o >> spi-nor-objs += catalyst.o >> spi-nor-objs += eon.o >> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c >> index 4a315cb1c4db..2eaf4ba8c0f3 100644 >> --- a/drivers/mtd/spi-nor/core.c >> +++ b/drivers/mtd/spi-nor/core.c >> @@ -3707,6 +3707,10 @@ static int spi_nor_probe(struct spi_mem >> *spimem) >> if (ret) >> return ret; >> >> + ret = spi_nor_sysfs_create(nor); >> + if (ret) >> + return ret; >> + >> return mtd_device_register(&nor->mtd, data ? data->parts : NULL, >> data ? data->nr_parts : 0); >> } >> @@ -3716,6 +3720,7 @@ static int spi_nor_remove(struct spi_mem >> *spimem) >> struct spi_nor *nor = spi_mem_get_drvdata(spimem); >> >> spi_nor_restore(nor); >> + spi_nor_sysfs_remove(nor); >> >> /* Clean up MTD stuff. */ >> return mtd_device_unregister(&nor->mtd); >> diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h >> index 668f22011b1d..dd592f7b62d1 100644 >> --- a/drivers/mtd/spi-nor/core.h >> +++ b/drivers/mtd/spi-nor/core.h >> @@ -488,4 +488,7 @@ static struct spi_nor __maybe_unused >> *mtd_to_spi_nor(struct mtd_info *mtd) >> return mtd->priv; >> } >> >> +int spi_nor_sysfs_create(struct spi_nor *nor); >> +void spi_nor_sysfs_remove(struct spi_nor *nor); >> + >> #endif /* __LINUX_MTD_SPI_NOR_INTERNAL_H */ >> diff --git a/drivers/mtd/spi-nor/sysfs.c b/drivers/mtd/spi-nor/sysfs.c >> new file mode 100644 >> index 000000000000..0de031e246c5 >> --- /dev/null >> +++ b/drivers/mtd/spi-nor/sysfs.c >> @@ -0,0 +1,86 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> + >> +#include <linux/mtd/spi-nor.h> >> +#include <linux/spi/spi.h> >> +#include <linux/spi/spi-mem.h> >> +#include <linux/sysfs.h> >> + >> +#include "core.h" >> + >> +static ssize_t name_show(struct device *dev, >> + struct device_attribute *attr, char *buf) >> +{ >> + struct spi_device *spi = to_spi_device(dev); >> + struct spi_mem *spimem = spi_get_drvdata(spi); >> + struct spi_nor *nor = spi_mem_get_drvdata(spimem); >> + >> + return sprintf(buf, "%s\n", nor->info->name); >> +} >> +static DEVICE_ATTR_RO(name); >> + >> +static ssize_t jedec_id_show(struct device *dev, >> + struct device_attribute *attr, char *buf) >> +{ >> + struct spi_device *spi = to_spi_device(dev); >> + struct spi_mem *spimem = spi_get_drvdata(spi); >> + struct spi_nor *nor = spi_mem_get_drvdata(spimem); >> + >> + return sprintf(buf, "%*phN\n", nor->info->id_len, nor->info->id); >> +} >> +static DEVICE_ATTR_RO(jedec_id); >> + >> +static struct attribute *spi_nor_sysfs_entries[] = { >> + &dev_attr_name.attr, >> + &dev_attr_jedec_id.attr, >> + NULL >> +}; >> + >> +static ssize_t sfdp_read(struct file *filp, struct kobject *kobj, >> + struct bin_attribute *bin_attr, char *buf, >> + loff_t off, size_t count) >> +{ >> + struct spi_device *spi = to_spi_device(kobj_to_dev(kobj)); >> + struct spi_mem *spimem = spi_get_drvdata(spi); >> + struct spi_nor *nor = spi_mem_get_drvdata(spimem); >> + struct sfdp *sfdp = nor->sfdp; >> + size_t sfdp_size = sfdp->num_dwords * sizeof(*sfdp->dwords); > > Is a NULL check needed here? If the flash does not have a SFDP table > nor->sfdp will be NULL. That can't happen because.. >> + >> + return memory_read_from_buffer(buf, count, &off, nor->sfdp->dwords, >> + sfdp_size); >> +} >> +static BIN_ATTR_RO(sfdp, PAGE_SIZE); >> + >> +static struct bin_attribute *spi_nor_sysfs_bin_entries[] = { >> + &bin_attr_sfdp, >> + NULL >> +}; >> + >> +static umode_t spi_nor_sysfs_is_bin_visible(struct kobject *kobj, >> + struct bin_attribute *attr, int n) >> +{ >> + struct spi_device *spi = to_spi_device(kobj_to_dev(kobj)); >> + struct spi_mem *spimem = spi_get_drvdata(spi); >> + struct spi_nor *nor = spi_mem_get_drvdata(spimem); >> + >> + if (attr == &bin_attr_sfdp && nor->sfdp) >> + return 0444; .. it is not visible. Maybe I should use if (attr == &bin_attr_sfdp && !nor->sfdp) return 0; return 0444; >> + >> + return 0; >> +} >> + >> +static struct attribute_group spi_nor_sysfs_attr_group = { >> + .name = NULL, >> + .is_bin_visible = spi_nor_sysfs_is_bin_visible, >> + .attrs = spi_nor_sysfs_entries, >> + .bin_attrs = spi_nor_sysfs_bin_entries, >> +}; >> + >> +int spi_nor_sysfs_create(struct spi_nor *nor) >> +{ >> + return sysfs_create_group(&nor->dev->kobj, >> &spi_nor_sysfs_attr_group); >> +} >> + >> +void spi_nor_sysfs_remove(struct spi_nor *nor) >> +{ >> + sysfs_remove_group(&nor->dev->kobj, &spi_nor_sysfs_attr_group); >> +} >> -- >> 2.20.1 >> > > Rest of it looks good to me. Thanks for reviewing! -michael
Hi, On 3/18/21 2:54 PM, Michael Walle wrote: > Add support to show the name and JEDEC identifier as well as to dump the > SFDP table. Not all flashes list their SFDP table contents in their > datasheet. So having that is useful. It might also be helpful in bug > reports from users. > Sorry for the delay.. There is already debugfs support for dumping JEDEC ID [1]. Any reason to add sysfs entry as well? That brings up another question. Since SFDP dumps are more of a debug aid, should this be a debugfs entry rather than sysfs entry? Note that sysfs entries are userspace ABIs just like syscalls and thus need to be documented in Documentation/ABI/testing/ or Documentation/ABI/stable. Thus need to be carefully designed compared to debugfs which are much more flexible. [1]drivers/mtd/spi-nor/core.c 3380 Regards Vignesh > The idea behind the sysfs module is also to have raw access to the SPI > NOR flash device registers, which can also be useful for debugging. > > Signed-off-by: Michael Walle <michael@walle.cc> > --- > drivers/mtd/spi-nor/Makefile | 2 +- > drivers/mtd/spi-nor/core.c | 5 +++ > drivers/mtd/spi-nor/core.h | 3 ++ > drivers/mtd/spi-nor/sysfs.c | 86 ++++++++++++++++++++++++++++++++++++ > 4 files changed, 95 insertions(+), 1 deletion(-) > create mode 100644 drivers/mtd/spi-nor/sysfs.c > > diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile > index 653923896205..aff308f75987 100644 > --- a/drivers/mtd/spi-nor/Makefile > +++ b/drivers/mtd/spi-nor/Makefile > @@ -1,6 +1,6 @@ > # SPDX-License-Identifier: GPL-2.0 > > -spi-nor-objs := core.o sfdp.o > +spi-nor-objs := core.o sfdp.o sysfs.o > spi-nor-objs += atmel.o > spi-nor-objs += catalyst.o > spi-nor-objs += eon.o > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c > index 4a315cb1c4db..2eaf4ba8c0f3 100644 > --- a/drivers/mtd/spi-nor/core.c > +++ b/drivers/mtd/spi-nor/core.c > @@ -3707,6 +3707,10 @@ static int spi_nor_probe(struct spi_mem *spimem) > if (ret) > return ret; > > + ret = spi_nor_sysfs_create(nor); > + if (ret) > + return ret; > + > return mtd_device_register(&nor->mtd, data ? data->parts : NULL, > data ? data->nr_parts : 0); > } > @@ -3716,6 +3720,7 @@ static int spi_nor_remove(struct spi_mem *spimem) > struct spi_nor *nor = spi_mem_get_drvdata(spimem); > > spi_nor_restore(nor); > + spi_nor_sysfs_remove(nor); > > /* Clean up MTD stuff. */ > return mtd_device_unregister(&nor->mtd); > diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h > index 668f22011b1d..dd592f7b62d1 100644 > --- a/drivers/mtd/spi-nor/core.h > +++ b/drivers/mtd/spi-nor/core.h > @@ -488,4 +488,7 @@ static struct spi_nor __maybe_unused *mtd_to_spi_nor(struct mtd_info *mtd) > return mtd->priv; > } > > +int spi_nor_sysfs_create(struct spi_nor *nor); > +void spi_nor_sysfs_remove(struct spi_nor *nor); > + > #endif /* __LINUX_MTD_SPI_NOR_INTERNAL_H */ > diff --git a/drivers/mtd/spi-nor/sysfs.c b/drivers/mtd/spi-nor/sysfs.c > new file mode 100644 > index 000000000000..0de031e246c5 > --- /dev/null > +++ b/drivers/mtd/spi-nor/sysfs.c > @@ -0,0 +1,86 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +#include <linux/mtd/spi-nor.h> > +#include <linux/spi/spi.h> > +#include <linux/spi/spi-mem.h> > +#include <linux/sysfs.h> > + > +#include "core.h" > + > +static ssize_t name_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct spi_device *spi = to_spi_device(dev); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + > + return sprintf(buf, "%s\n", nor->info->name); > +} > +static DEVICE_ATTR_RO(name); > + > +static ssize_t jedec_id_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct spi_device *spi = to_spi_device(dev); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + > + return sprintf(buf, "%*phN\n", nor->info->id_len, nor->info->id); > +} > +static DEVICE_ATTR_RO(jedec_id); > + > +static struct attribute *spi_nor_sysfs_entries[] = { > + &dev_attr_name.attr, > + &dev_attr_jedec_id.attr, > + NULL > +}; > + > +static ssize_t sfdp_read(struct file *filp, struct kobject *kobj, > + struct bin_attribute *bin_attr, char *buf, > + loff_t off, size_t count) > +{ > + struct spi_device *spi = to_spi_device(kobj_to_dev(kobj)); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + struct sfdp *sfdp = nor->sfdp; > + size_t sfdp_size = sfdp->num_dwords * sizeof(*sfdp->dwords); > + > + return memory_read_from_buffer(buf, count, &off, nor->sfdp->dwords, > + sfdp_size); > +} > +static BIN_ATTR_RO(sfdp, PAGE_SIZE); > + > +static struct bin_attribute *spi_nor_sysfs_bin_entries[] = { > + &bin_attr_sfdp, > + NULL > +}; > + > +static umode_t spi_nor_sysfs_is_bin_visible(struct kobject *kobj, > + struct bin_attribute *attr, int n) > +{ > + struct spi_device *spi = to_spi_device(kobj_to_dev(kobj)); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + > + if (attr == &bin_attr_sfdp && nor->sfdp) > + return 0444; > + > + return 0; > +} > + > +static struct attribute_group spi_nor_sysfs_attr_group = { > + .name = NULL, > + .is_bin_visible = spi_nor_sysfs_is_bin_visible, > + .attrs = spi_nor_sysfs_entries, > + .bin_attrs = spi_nor_sysfs_bin_entries, > +}; > + > +int spi_nor_sysfs_create(struct spi_nor *nor) > +{ > + return sysfs_create_group(&nor->dev->kobj, &spi_nor_sysfs_attr_group); > +} > + > +void spi_nor_sysfs_remove(struct spi_nor *nor) > +{ > + sysfs_remove_group(&nor->dev->kobj, &spi_nor_sysfs_attr_group); > +} >
Hi, Am 2021-04-06 09:56, schrieb Vignesh Raghavendra: > Hi, > > On 3/18/21 2:54 PM, Michael Walle wrote: >> Add support to show the name and JEDEC identifier as well as to dump >> the >> SFDP table. Not all flashes list their SFDP table contents in their >> datasheet. So having that is useful. It might also be helpful in bug >> reports from users. >> > > Sorry for the delay.. > > There is already debugfs support for dumping JEDEC ID [1]. Any reason > to > add sysfs entry as well? This is per mtd while the sfdp is per flash device. IMHO both should be at the same place. > That brings up another question. Since SFDP dumps are more of a debug > aid, should this be a debugfs entry rather than sysfs entry? And you're not the first one asking that. My argument was that the debugfs might not be available just when you need it. A developer could easily rebuild a kernel, but imagine some user with a COTS distro and some problems, then it is not that easy anymore. But thats your call to make. > Note that sysfs entries are userspace ABIs just like syscalls and thus > need to be documented in Documentation/ABI/testing/ or > Documentation/ABI/stable. Thus need to be carefully designed compared > to > debugfs which are much more flexible. Ok. But I don't see a problem adding these read-only files /sfdp /name /jedec-id Do you? -michael
On 4/6/21 2:17 PM, Michael Walle wrote: > Hi, > > Am 2021-04-06 09:56, schrieb Vignesh Raghavendra: >> Hi, >> >> On 3/18/21 2:54 PM, Michael Walle wrote: >>> Add support to show the name and JEDEC identifier as well as to dump the >>> SFDP table. Not all flashes list their SFDP table contents in their >>> datasheet. So having that is useful. It might also be helpful in bug >>> reports from users. >>> >> >> Sorry for the delay.. >> >> There is already debugfs support for dumping JEDEC ID [1]. Any reason to >> add sysfs entry as well? > > This is per mtd while the sfdp is per flash device. IMHO both should > be at the same place. > >> That brings up another question. Since SFDP dumps are more of a debug >> aid, should this be a debugfs entry rather than sysfs entry? > > And you're not the first one asking that. My argument was that the > debugfs might not be available just when you need it. A developer > could easily rebuild a kernel, but imagine some user with a COTS > distro and some problems, then it is not that easy anymore. But > thats your call to make. > >> Note that sysfs entries are userspace ABIs just like syscalls and thus >> need to be documented in Documentation/ABI/testing/ or >> Documentation/ABI/stable. Thus need to be carefully designed compared to >> debugfs which are much more flexible. > > Ok. But I don't see a problem adding these read-only files > /sfdp > /name > /jedec-id > Hmm, ok. but do add documentation please. Regards Vignesh
Hi Michael, > On Thu, Mar 18, 2021 at 10:24 AM Michael Walle <michael@walle.cc> > wrote: > Add support to show the name and JEDEC identifier as well as to dump the > SFDP table. Not all flashes list their SFDP table contents in their > datasheet. So having that is useful. It might also be helpful in bug > reports from users. > > The idea behind the sysfs module is also to have raw access to the SPI > NOR flash device registers, which can also be useful for debugging. > > Signed-off-by: Michael Walle <michael@walle.cc> > --- > drivers/mtd/spi-nor/Makefile | 2 +- > drivers/mtd/spi-nor/core.c | 5 +++ > drivers/mtd/spi-nor/core.h | 3 ++ > drivers/mtd/spi-nor/sysfs.c | 86 ++++++++++++++++++++++++++++++++++++ > 4 files changed, 95 insertions(+), 1 deletion(-) > create mode 100644 drivers/mtd/spi-nor/sysfs.c > > diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile > index 653923896205..aff308f75987 100644 > --- a/drivers/mtd/spi-nor/Makefile > +++ b/drivers/mtd/spi-nor/Makefile > @@ -1,6 +1,6 @@ > # SPDX-License-Identifier: GPL-2.0 > > -spi-nor-objs := core.o sfdp.o > +spi-nor-objs := core.o sfdp.o sysfs.o > spi-nor-objs += atmel.o > spi-nor-objs += catalyst.o > spi-nor-objs += eon.o > diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c > index 4a315cb1c4db..2eaf4ba8c0f3 100644 > --- a/drivers/mtd/spi-nor/core.c > +++ b/drivers/mtd/spi-nor/core.c > @@ -3707,6 +3707,10 @@ static int spi_nor_probe(struct spi_mem *spimem) > if (ret) > return ret; > > + ret = spi_nor_sysfs_create(nor); This appears to be racing with user space. By the time we reach probe(), the device embedded in the spi_device has already been registered, with the uevent sent out, right? udev may not see the new attributes created here. Since we reuse a preexisting device throughout spi-nor, it seems awfully challenging to be able to safely add sysfs attributes. Would it make sense to create a spi-nor-specific device/class? Or perhaps attach these attributes to the device in mtd_info like I've done in https://lore.kernel.org/linux-mtd/20210428052725.530939-1-awill@google.com/ ? - Alex > + if (ret) > + return ret; > + > return mtd_device_register(&nor->mtd, data ? data->parts : NULL, > data ? data->nr_parts : 0); > } > @@ -3716,6 +3720,7 @@ static int spi_nor_remove(struct spi_mem *spimem) > struct spi_nor *nor = spi_mem_get_drvdata(spimem); > > spi_nor_restore(nor); > + spi_nor_sysfs_remove(nor); > > /* Clean up MTD stuff. */ > return mtd_device_unregister(&nor->mtd); > diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h > index 668f22011b1d..dd592f7b62d1 100644 > --- a/drivers/mtd/spi-nor/core.h > +++ b/drivers/mtd/spi-nor/core.h > @@ -488,4 +488,7 @@ static struct spi_nor __maybe_unused *mtd_to_spi_nor(struct mtd_info *mtd) > return mtd->priv; > } > > +int spi_nor_sysfs_create(struct spi_nor *nor); > +void spi_nor_sysfs_remove(struct spi_nor *nor); > + > #endif /* __LINUX_MTD_SPI_NOR_INTERNAL_H */ > diff --git a/drivers/mtd/spi-nor/sysfs.c b/drivers/mtd/spi-nor/sysfs.c > new file mode 100644 > index 000000000000..0de031e246c5 > --- /dev/null > +++ b/drivers/mtd/spi-nor/sysfs.c > @@ -0,0 +1,86 @@ > +// SPDX-License-Identifier: GPL-2.0 > + > +#include <linux/mtd/spi-nor.h> > +#include <linux/spi/spi.h> > +#include <linux/spi/spi-mem.h> > +#include <linux/sysfs.h> > + > +#include "core.h" > + > +static ssize_t name_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct spi_device *spi = to_spi_device(dev); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + > + return sprintf(buf, "%s\n", nor->info->name); > +} > +static DEVICE_ATTR_RO(name); > + > +static ssize_t jedec_id_show(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct spi_device *spi = to_spi_device(dev); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + > + return sprintf(buf, "%*phN\n", nor->info->id_len, nor->info->id); > +} > +static DEVICE_ATTR_RO(jedec_id); > + > +static struct attribute *spi_nor_sysfs_entries[] = { > + &dev_attr_name.attr, > + &dev_attr_jedec_id.attr, > + NULL > +}; > + > +static ssize_t sfdp_read(struct file *filp, struct kobject *kobj, > + struct bin_attribute *bin_attr, char *buf, > + loff_t off, size_t count) > +{ > + struct spi_device *spi = to_spi_device(kobj_to_dev(kobj)); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + struct sfdp *sfdp = nor->sfdp; > + size_t sfdp_size = sfdp->num_dwords * sizeof(*sfdp->dwords); > + > + return memory_read_from_buffer(buf, count, &off, nor->sfdp->dwords, > + sfdp_size); > +} > +static BIN_ATTR_RO(sfdp, PAGE_SIZE); > + > +static struct bin_attribute *spi_nor_sysfs_bin_entries[] = { > + &bin_attr_sfdp, > + NULL > +}; > + > +static umode_t spi_nor_sysfs_is_bin_visible(struct kobject *kobj, > + struct bin_attribute *attr, int n) > +{ > + struct spi_device *spi = to_spi_device(kobj_to_dev(kobj)); > + struct spi_mem *spimem = spi_get_drvdata(spi); > + struct spi_nor *nor = spi_mem_get_drvdata(spimem); > + > + if (attr == &bin_attr_sfdp && nor->sfdp) > + return 0444; > + > + return 0; > +} > + > +static struct attribute_group spi_nor_sysfs_attr_group = { > + .name = NULL, > + .is_bin_visible = spi_nor_sysfs_is_bin_visible, > + .attrs = spi_nor_sysfs_entries, > + .bin_attrs = spi_nor_sysfs_bin_entries, > +}; > + > +int spi_nor_sysfs_create(struct spi_nor *nor) > +{ > + return sysfs_create_group(&nor->dev->kobj, &spi_nor_sysfs_attr_group); > +} > + > +void spi_nor_sysfs_remove(struct spi_nor *nor) > +{ > + sysfs_remove_group(&nor->dev->kobj, &spi_nor_sysfs_attr_group); > +} > -- > 2.20.1
Hi Alex, Am 2021-04-29 17:37, schrieb Alexander Williams: > Hi Michael, > >> On Thu, Mar 18, 2021 at 10:24 AM Michael Walle <michael@walle.cc> >> wrote: >> Add support to show the name and JEDEC identifier as well as to dump >> the >> SFDP table. Not all flashes list their SFDP table contents in their >> datasheet. So having that is useful. It might also be helpful in bug >> reports from users. >> >> The idea behind the sysfs module is also to have raw access to the SPI >> NOR flash device registers, which can also be useful for debugging. >> >> Signed-off-by: Michael Walle <michael@walle.cc> >> --- >> drivers/mtd/spi-nor/Makefile | 2 +- >> drivers/mtd/spi-nor/core.c | 5 +++ >> drivers/mtd/spi-nor/core.h | 3 ++ >> drivers/mtd/spi-nor/sysfs.c | 86 >> ++++++++++++++++++++++++++++++++++++ >> 4 files changed, 95 insertions(+), 1 deletion(-) >> create mode 100644 drivers/mtd/spi-nor/sysfs.c >> >> diff --git a/drivers/mtd/spi-nor/Makefile >> b/drivers/mtd/spi-nor/Makefile >> index 653923896205..aff308f75987 100644 >> --- a/drivers/mtd/spi-nor/Makefile >> +++ b/drivers/mtd/spi-nor/Makefile >> @@ -1,6 +1,6 @@ >> # SPDX-License-Identifier: GPL-2.0 >> >> -spi-nor-objs := core.o sfdp.o >> +spi-nor-objs := core.o sfdp.o sysfs.o >> spi-nor-objs += atmel.o >> spi-nor-objs += catalyst.o >> spi-nor-objs += eon.o >> diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c >> index 4a315cb1c4db..2eaf4ba8c0f3 100644 >> --- a/drivers/mtd/spi-nor/core.c >> +++ b/drivers/mtd/spi-nor/core.c >> @@ -3707,6 +3707,10 @@ static int spi_nor_probe(struct spi_mem >> *spimem) >> if (ret) >> return ret; >> >> + ret = spi_nor_sysfs_create(nor); > > This appears to be racing with user space. By the time we reach > probe(), the > device embedded in the spi_device has already been registered, with the > uevent > sent out, right? udev may not see the new attributes created here. > > Since we reuse a preexisting device throughout spi-nor, it seems > awfully > challenging to be able to safely add sysfs attributes. Would it make > sense to > create a spi-nor-specific device/class? Or perhaps attach these > attributes to > the device in mtd_info like I've done in > https://lore.kernel.org/linux-mtd/20210428052725.530939-1-awill@google.com/ > ? Do you encounter this problem? I'm currently working on this and dropped the sysfs_create() and use dev_groups of the driver spi nor driver. But I'm not sure how it will be handled anyway. Because we know the content/size SFDP only after the probe and in any case the probe could also fail. So I don't really understand how that is handled. I've looked at your patch and it seems that the surpress_uevent() is rarely used in the kernel. I don't want to attach it to an MTD device because you might have multiple ones which has the same SPI flash device as parent. The SFDP is really a property of the flash device and not one of the MTD partition. -michael
diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile index 653923896205..aff308f75987 100644 --- a/drivers/mtd/spi-nor/Makefile +++ b/drivers/mtd/spi-nor/Makefile @@ -1,6 +1,6 @@ # SPDX-License-Identifier: GPL-2.0 -spi-nor-objs := core.o sfdp.o +spi-nor-objs := core.o sfdp.o sysfs.o spi-nor-objs += atmel.o spi-nor-objs += catalyst.o spi-nor-objs += eon.o diff --git a/drivers/mtd/spi-nor/core.c b/drivers/mtd/spi-nor/core.c index 4a315cb1c4db..2eaf4ba8c0f3 100644 --- a/drivers/mtd/spi-nor/core.c +++ b/drivers/mtd/spi-nor/core.c @@ -3707,6 +3707,10 @@ static int spi_nor_probe(struct spi_mem *spimem) if (ret) return ret; + ret = spi_nor_sysfs_create(nor); + if (ret) + return ret; + return mtd_device_register(&nor->mtd, data ? data->parts : NULL, data ? data->nr_parts : 0); } @@ -3716,6 +3720,7 @@ static int spi_nor_remove(struct spi_mem *spimem) struct spi_nor *nor = spi_mem_get_drvdata(spimem); spi_nor_restore(nor); + spi_nor_sysfs_remove(nor); /* Clean up MTD stuff. */ return mtd_device_unregister(&nor->mtd); diff --git a/drivers/mtd/spi-nor/core.h b/drivers/mtd/spi-nor/core.h index 668f22011b1d..dd592f7b62d1 100644 --- a/drivers/mtd/spi-nor/core.h +++ b/drivers/mtd/spi-nor/core.h @@ -488,4 +488,7 @@ static struct spi_nor __maybe_unused *mtd_to_spi_nor(struct mtd_info *mtd) return mtd->priv; } +int spi_nor_sysfs_create(struct spi_nor *nor); +void spi_nor_sysfs_remove(struct spi_nor *nor); + #endif /* __LINUX_MTD_SPI_NOR_INTERNAL_H */ diff --git a/drivers/mtd/spi-nor/sysfs.c b/drivers/mtd/spi-nor/sysfs.c new file mode 100644 index 000000000000..0de031e246c5 --- /dev/null +++ b/drivers/mtd/spi-nor/sysfs.c @@ -0,0 +1,86 @@ +// SPDX-License-Identifier: GPL-2.0 + +#include <linux/mtd/spi-nor.h> +#include <linux/spi/spi.h> +#include <linux/spi/spi-mem.h> +#include <linux/sysfs.h> + +#include "core.h" + +static ssize_t name_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct spi_device *spi = to_spi_device(dev); + struct spi_mem *spimem = spi_get_drvdata(spi); + struct spi_nor *nor = spi_mem_get_drvdata(spimem); + + return sprintf(buf, "%s\n", nor->info->name); +} +static DEVICE_ATTR_RO(name); + +static ssize_t jedec_id_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct spi_device *spi = to_spi_device(dev); + struct spi_mem *spimem = spi_get_drvdata(spi); + struct spi_nor *nor = spi_mem_get_drvdata(spimem); + + return sprintf(buf, "%*phN\n", nor->info->id_len, nor->info->id); +} +static DEVICE_ATTR_RO(jedec_id); + +static struct attribute *spi_nor_sysfs_entries[] = { + &dev_attr_name.attr, + &dev_attr_jedec_id.attr, + NULL +}; + +static ssize_t sfdp_read(struct file *filp, struct kobject *kobj, + struct bin_attribute *bin_attr, char *buf, + loff_t off, size_t count) +{ + struct spi_device *spi = to_spi_device(kobj_to_dev(kobj)); + struct spi_mem *spimem = spi_get_drvdata(spi); + struct spi_nor *nor = spi_mem_get_drvdata(spimem); + struct sfdp *sfdp = nor->sfdp; + size_t sfdp_size = sfdp->num_dwords * sizeof(*sfdp->dwords); + + return memory_read_from_buffer(buf, count, &off, nor->sfdp->dwords, + sfdp_size); +} +static BIN_ATTR_RO(sfdp, PAGE_SIZE); + +static struct bin_attribute *spi_nor_sysfs_bin_entries[] = { + &bin_attr_sfdp, + NULL +}; + +static umode_t spi_nor_sysfs_is_bin_visible(struct kobject *kobj, + struct bin_attribute *attr, int n) +{ + struct spi_device *spi = to_spi_device(kobj_to_dev(kobj)); + struct spi_mem *spimem = spi_get_drvdata(spi); + struct spi_nor *nor = spi_mem_get_drvdata(spimem); + + if (attr == &bin_attr_sfdp && nor->sfdp) + return 0444; + + return 0; +} + +static struct attribute_group spi_nor_sysfs_attr_group = { + .name = NULL, + .is_bin_visible = spi_nor_sysfs_is_bin_visible, + .attrs = spi_nor_sysfs_entries, + .bin_attrs = spi_nor_sysfs_bin_entries, +}; + +int spi_nor_sysfs_create(struct spi_nor *nor) +{ + return sysfs_create_group(&nor->dev->kobj, &spi_nor_sysfs_attr_group); +} + +void spi_nor_sysfs_remove(struct spi_nor *nor) +{ + sysfs_remove_group(&nor->dev->kobj, &spi_nor_sysfs_attr_group); +}
Add support to show the name and JEDEC identifier as well as to dump the SFDP table. Not all flashes list their SFDP table contents in their datasheet. So having that is useful. It might also be helpful in bug reports from users. The idea behind the sysfs module is also to have raw access to the SPI NOR flash device registers, which can also be useful for debugging. Signed-off-by: Michael Walle <michael@walle.cc> --- drivers/mtd/spi-nor/Makefile | 2 +- drivers/mtd/spi-nor/core.c | 5 +++ drivers/mtd/spi-nor/core.h | 3 ++ drivers/mtd/spi-nor/sysfs.c | 86 ++++++++++++++++++++++++++++++++++++ 4 files changed, 95 insertions(+), 1 deletion(-) create mode 100644 drivers/mtd/spi-nor/sysfs.c