[PATCH AUTOSEL 5.7 044/388] nvmem: ensure sysfs writes handle write-protect pin

Sasha Levin
2020-06-18T02:51:12Z

From: Michael Auchter <michael.auchter@ni.com>

[ Upstream commit b96fc5416b099a0c2509ca07a80b140d34db2b9b ]

Commit 2a127da461a9 ("nvmem: add support for the write-protect pin")
added support for handling write-protect pins to the nvmem core, and
Commit 1c89074bf850 ("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: 2a127da461a9 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/nvmem/core.c | 52 ++++++++++++++++++++++----------------------
1 file changed, 26 insertions(+), 26 deletions(-)

diff --git a/drivers/nvmem/core.c b/drivers/nvmem/core.c
index 05c6ae4b0b97..a8300202a7fb 100644
--- a/drivers/nvmem/core.c
+++ b/drivers/nvmem/core.c
@@ -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;
@@ -311,30 +335,6 @@ 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);
--
2.25.1