On 3/8/2024 13:50, Armin Wolf wrote:
The ACPI EC address space handler currently only supports
reading/writing 8 bit values. Some firmware implementations however
want to access for example 16 bit values, which is prefectly legal
according to the ACPI spec.
Add support for reading/writing such values.
Tested on a Dell Inspiron 3505 and a Asus Prime B650-Plus.
Signed-off-by: Armin Wolf <W_Armin@xxxxxx>
---
Chnages since v2:
- fix address overflow check
Changes since v1:
- use BITS_PER_BYTE
- validate that number of bytes to read/write does not overflow the
address
---
drivers/platform/x86/wmi.c | 47 ++++++++++++++++++++++++++++++--------
1 file changed, 37 insertions(+), 10 deletions(-)
diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c
index 1920e115da89..e6cab1cf611a 100644
--- a/drivers/platform/x86/wmi.c
+++ b/drivers/platform/x86/wmi.c
@@ -1153,6 +1153,32 @@ static int parse_wdg(struct device *wmi_bus_dev, struct platform_device *pdev)
return 0;
}
+static int ec_read_multiple(u8 address, u8 *buffer, size_t bytes)
+{
+ int i, ret;
+
+ for (i = 0; i < bytes; i++) {
To make sure that you're comparing against the same size data you should
either i "size_t" instead of "int".
+ ret = ec_read(address + i, &buffer[i]);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
+static int ec_write_multiple(u8 address, u8 *buffer, size_t bytes)
+{
+ int i, ret;
+
+ for (i = 0; i < bytes; i++) {
Same comment as above.
+ ret = ec_write(address + i, buffer[i]);
+ if (ret < 0)
+ return ret;
+ }
+
+ return 0;
+}
+
/*
* WMI can have EmbeddedControl access regions. In which case, we just want to
* hand these off to the EC driver.
@@ -1162,27 +1188,28 @@ acpi_wmi_ec_space_handler(u32 function, acpi_physical_address address,
u32 bits, u64 *value,
void *handler_context, void *region_context)
{
- int result = 0;
- u8 temp = 0;
+ int bytes = bits / BITS_PER_BYTE;
+ int ret;
+
+ if (!value)
+ return AE_NULL_ENTRY;
- if ((address > 0xFF) || !value)
+ if (!bytes || bytes > sizeof(*value))
return AE_BAD_PARAMETER;
- if (function != ACPI_READ && function != ACPI_WRITE)
+ if (address > U8_MAX || address + bytes - 1 > U8_MAX)
return AE_BAD_PARAMETER;
- if (bits != 8)
+ if (function != ACPI_READ && function != ACPI_WRITE)
return AE_BAD_PARAMETER;
if (function == ACPI_READ) {
- result = ec_read(address, &temp);
- *value = temp;
+ ret = ec_read_multiple(address, (u8 *)value, bytes);
} else {
- temp = 0xff & *value;
- result = ec_write(address, temp);
+ ret = ec_write_multiple(address, (u8 *)value, bytes);
}
- switch (result) {
+ switch (ret) {
case -EINVAL:
return AE_BAD_PARAMETER;
case -ENODEV:
--
2.39.2
