| Message ID | 20240308195027.7640-1-W_Armin@gmx.de (mailing list archive) |
|---|---|
| State | Superseded, archived |
| Headers | show |
| Series | [v3,1/2] platform/x86: wmi: Support reading/writing 16 bit EC values | expand |
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@gmx.de> > --- > 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 > >
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++) { + 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++) { + 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:
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@gmx.de> --- 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(-) -- 2.39.2