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nvmem: ensure sysfs writes handle write-protect pin 

Commit 2a127da461 ("nvmem: add support for the write-protect pin")
added support for handling write-protect pins to the nvmem core, and
Commit 1c89074bf8 ("eeprom: at24: remove the write-protect pin support")
retrofitted the at24 driver to use this support.

These changes broke write() on the nvmem sysfs attribute for eeproms
which utilize a write-protect pin, as the write callback invokes the
nvmem device's reg_write callback directly which no longer handles
changing the state of the write-protect pin.

Change the read and write callbacks for the sysfs attribute to invoke
nvmme_reg_read/nvmem_reg_write helpers which handle this, rather than
calling reg_read/reg_write directly.

Fixes: 2a127da461 ("nvmem: add support for the write-protect pin")
Signed-off-by: Michael Auchter <michael.auchter@ni.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20200511145042.31223-3-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Michael Auchter 2020-05-11 15:50:41 +01:00 committed by Greg Kroah-Hartman
parent 0e2abffdf9
commit b96fc5416b
1 changed files with 26 additions and 26 deletions
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52
drivers/nvmem/core.c
View File

@ -66,6 +66,30 @@ static LIST_HEAD(nvmem_lookup_list);
static BLOCKING_NOTIFIER_HEAD(nvmem_notifier);
static int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
void *val, size_t bytes)
{
if (nvmem->reg_read)
return nvmem->reg_read(nvmem->priv, offset, val, bytes);
return -EINVAL;
}
static int nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset,
void *val, size_t bytes)
{
int ret;
if (nvmem->reg_write) {
gpiod_set_value_cansleep(nvmem->wp_gpio, 0);
ret = nvmem->reg_write(nvmem->priv, offset, val, bytes);
gpiod_set_value_cansleep(nvmem->wp_gpio, 1);
return ret;
}
return -EINVAL;
}
#ifdef CONFIG_NVMEM_SYSFS
static const char * const nvmem_type_str[] = {
[NVMEM_TYPE_UNKNOWN] = "Unknown",
@ -122,7 +146,7 @@ static ssize_t bin_attr_nvmem_read(struct file *filp, struct kobject *kobj,
if (!nvmem->reg_read)
return -EPERM;
rc = nvmem->reg_read(nvmem->priv, pos, buf, count);
rc = nvmem_reg_read(nvmem, pos, buf, count);
if (rc)
return rc;
@ -159,7 +183,7 @@ static ssize_t bin_attr_nvmem_write(struct file *filp, struct kobject *kobj,
if (!nvmem->reg_write)
return -EPERM;
rc = nvmem->reg_write(nvmem->priv, pos, buf, count);
rc = nvmem_reg_write(nvmem, pos, buf, count);
if (rc)
return rc;
@ -287,30 +311,6 @@ static void nvmem_sysfs_remove_compat(struct nvmem_device *nvmem,
#endif /* CONFIG_NVMEM_SYSFS */
static int nvmem_reg_read(struct nvmem_device *nvmem, unsigned int offset,
void *val, size_t bytes)
{
if (nvmem->reg_read)
return nvmem->reg_read(nvmem->priv, offset, val, bytes);
return -EINVAL;
}
static int nvmem_reg_write(struct nvmem_device *nvmem, unsigned int offset,
void *val, size_t bytes)
{
int ret;
if (nvmem->reg_write) {
gpiod_set_value_cansleep(nvmem->wp_gpio, 0);
ret = nvmem->reg_write(nvmem->priv, offset, val, bytes);
gpiod_set_value_cansleep(nvmem->wp_gpio, 1);
return ret;
}
return -EINVAL;
}
static void nvmem_release(struct device *dev)
{
struct nvmem_device *nvmem = to_nvmem_device(dev);