On Mon, Oct 7, 2019 at 3:16 PM Cheng-Yi Chiang cychiang@chromium.org wrote:
Add an interface for other driver to query VPD value. This will be used for ASoC machine driver to query calibration data stored in VPD for smart amplifier speaker resistor calibration.
Signed-off-by: Cheng-Yi Chiang cychiang@chromium.org
drivers/firmware/google/vpd.c | 16 ++++++++++++++++ include/linux/firmware/google/google_vpd.h | 18 ++++++++++++++++++ 2 files changed, 34 insertions(+) create mode 100644 include/linux/firmware/google/google_vpd.h
diff --git a/drivers/firmware/google/vpd.c b/drivers/firmware/google/vpd.c index db0812263d46..71e9d2da63be 100644 --- a/drivers/firmware/google/vpd.c +++ b/drivers/firmware/google/vpd.c @@ -65,6 +65,22 @@ static ssize_t vpd_attrib_read(struct file *filp, struct kobject *kobp, info->bin_attr.size); }
+int vpd_attribute_read_value(bool ro, const char *key,
char **value, u32 value_len)+{
struct vpd_attrib_info *info;struct vpd_section *sec = ro ? &ro_vpd : &rw_vpd;list_for_each_entry(info, &sec->attribs, list) {if (strcmp(info->key, key) == 0) {*value = kstrndup(info->value, value_len, GFP_KERNEL);
Value is not necessary a NULL-terminated string. kmalloc(info->bin_attr.size) and memcpy(...) would make the most sense.
The value_len parameter makes less sense. It seems the caller knows the length of the value in advance. Suggest to change the value_len to report the length of value. I.e. *value_len = info->bin_attr.size;
Also please check the return value for memory allocation-like functions (e.g. kstrndup, kmalloc) so that *value won't be NULL but the function returned 0.
return 0;}}return -EINVAL;+} +EXPORT_SYMBOL(vpd_attribute_read_value);
/*
- vpd_section_check_key_name()
diff --git a/include/linux/firmware/google/google_vpd.h b/include/linux/firmware/google/google_vpd.h new file mode 100644 index 000000000000..6f1160f28af8 --- /dev/null +++ b/include/linux/firmware/google/google_vpd.h @@ -0,0 +1,18 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/*
- Google VPD interface.
- Copyright 2019 Google Inc.
- */
+/* Interface for reading VPD value on Chrome platform. */
+#ifndef __GOOGLE_VPD_H +#define __GOOGLE_VPD_H
+#include <linux/types.h>
+int vpd_attribute_read_value(bool ro, const char *key,
char **value, u32 value_len);+#endif /* __GOOGLE_VPD_H */
2.23.0.581.g78d2f28ef7-goog