From 648a488216837bda04114b700246011316b44478 Mon Sep 17 00:00:00 2001 From: Shengtan Mao Date: Mon, 7 Mar 2022 12:06:02 -0800 Subject: [PATCH] hw/i2c: Added linear mode translation for pmbus devices MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Shengtan Mao Reviewed-by: Titus Rwantare Reviewed-by: Philippe Mathieu-Daudé Acked-by: Corey Minyard Message-Id: <20220307200605.4001451-7-titusr@google.com> Signed-off-by: Philippe Mathieu-Daudé --- hw/i2c/pmbus_device.c | 18 ++++++++++++++++++ include/hw/i2c/pmbus_device.h | 20 +++++++++++++++++++- 2 files changed, 37 insertions(+), 1 deletion(-) diff --git a/hw/i2c/pmbus_device.c b/hw/i2c/pmbus_device.c index 8cb9db0f80..62885fa6a1 100644 --- a/hw/i2c/pmbus_device.c +++ b/hw/i2c/pmbus_device.c @@ -28,6 +28,24 @@ uint32_t pmbus_direct_mode2data(PMBusCoefficients c, uint16_t value) return x; } +uint16_t pmbus_data2linear_mode(uint16_t value, int exp) +{ + /* L = D * 2^(-e) */ + if (exp < 0) { + return value << (-exp); + } + return value >> exp; +} + +uint16_t pmbus_linear_mode2data(uint16_t value, int exp) +{ + /* D = L * 2^e */ + if (exp < 0) { + return value >> (-exp); + } + return value << exp; +} + void pmbus_send(PMBusDevice *pmdev, const uint8_t *data, uint16_t len) { if (pmdev->out_buf_len + len > SMBUS_DATA_MAX_LEN) { diff --git a/include/hw/i2c/pmbus_device.h b/include/hw/i2c/pmbus_device.h index bab4526734..0f4d6b3fad 100644 --- a/include/hw/i2c/pmbus_device.h +++ b/include/hw/i2c/pmbus_device.h @@ -448,7 +448,7 @@ typedef struct PMBusCoefficients { * * Y = (m * x - b) * 10^R * - * @return uint32_t + * @return uint16_t */ uint16_t pmbus_data2direct_mode(PMBusCoefficients c, uint32_t value); @@ -461,6 +461,24 @@ uint16_t pmbus_data2direct_mode(PMBusCoefficients c, uint32_t value); */ uint32_t pmbus_direct_mode2data(PMBusCoefficients c, uint16_t value); +/** + * Convert sensor values to linear mode format + * + * L = D * 2^(-e) + * + * @return uint16 + */ +uint16_t pmbus_data2linear_mode(uint16_t value, int exp); + +/** + * Convert linear mode formatted data into sensor reading + * + * D = L * 2^e + * + * @return uint16 + */ +uint16_t pmbus_linear_mode2data(uint16_t value, int exp); + /** * @brief Send a block of data over PMBus * Assumes that the bytes in the block are already ordered correctly,