On Wed, 31 May 2023 13:47:42 +0200
Klaus Jensen <i...@irrelevant.dk> wrote:
> From: Klaus Jensen <k.jen...@samsung.com>
>
> Add i2c_smbus_pec() to calculate the SMBus Packet Error Code for a
> message.
>
> Signed-off-by: Klaus Jensen <k.jen...@samsung.com>
LGTM
Reviewed-by: Jonathan Cameron <jonathan.came...@huawei.com>
> ---
> hw/i2c/smbus_master.c | 28 ++++++++++++++++++++++++++++
> include/hw/i2c/smbus_master.h | 2 ++
> 2 files changed, 30 insertions(+)
>
> diff --git a/hw/i2c/smbus_master.c b/hw/i2c/smbus_master.c
> index 6a53c34e70b7..47f9eb24e033 100644
> --- a/hw/i2c/smbus_master.c
> +++ b/hw/i2c/smbus_master.c
> @@ -15,6 +15,34 @@
> #include "hw/i2c/i2c.h"
> #include "hw/i2c/smbus_master.h"
>
> +static uint8_t crc8(uint16_t data)
> +{
> +#define POLY (0x1070U << 3)
> + int i;
> +
> + for (i = 0; i < 8; i++) {
> + if (data & 0x8000) {
> + data = data ^ POLY;
> + }
> +
> + data = data << 1;
> + }
> +
> + return (uint8_t)(data >> 8);
> +#undef POLY
> +}
> +
> +uint8_t i2c_smbus_pec(uint8_t crc, uint8_t *buf, size_t len)
> +{
> + int i;
> +
> + for (i = 0; i < len; i++) {
> + crc = crc8((crc ^ buf[i]) << 8);
> + }
> +
> + return crc;
> +}
> +
> /* Master device commands. */
> int smbus_quick_command(I2CBus *bus, uint8_t addr, int read)
> {
> diff --git a/include/hw/i2c/smbus_master.h b/include/hw/i2c/smbus_master.h
> index bb13bc423c22..d90f81767d86 100644
> --- a/include/hw/i2c/smbus_master.h
> +++ b/include/hw/i2c/smbus_master.h
> @@ -27,6 +27,8 @@
>
> #include "hw/i2c/i2c.h"
>
> +uint8_t i2c_smbus_pec(uint8_t crc, uint8_t *buf, size_t len);
> +
> /* Master device commands. */
> int smbus_quick_command(I2CBus *bus, uint8_t addr, int read);
> int smbus_receive_byte(I2CBus *bus, uint8_t addr);
