From 8e926134ef15267f65ddfc7389c8078234610295 Mon Sep 17 00:00:00 2001 From: Hartmut Knaack Date: Sun, 31 May 2015 14:39:58 +0200 Subject: tools:iio:generic_buffer: sign-extend and shift data Refactor process_scan() to handle signed and unsigned data, respect shifts and the data mask for 2, 4 and 8 byte sized scan elements. Signed-off-by: Hartmut Knaack Signed-off-by: Jonathan Cameron --- tools/iio/generic_buffer.c | 97 +++++++++++++++++++++++++++++----------------- 1 file changed, 62 insertions(+), 35 deletions(-) diff --git a/tools/iio/generic_buffer.c b/tools/iio/generic_buffer.c index 419e22736c3a..4cd246426b57 100644 --- a/tools/iio/generic_buffer.c +++ b/tools/iio/generic_buffer.c @@ -59,33 +59,80 @@ int size_from_channelarray(struct iio_channel_info *channels, int num_channels) return bytes; } -void print2byte(int input, struct iio_channel_info *info) +void print2byte(uint16_t input, struct iio_channel_info *info) { /* First swap if incorrect endian */ if (info->be) - input = be16toh((uint16_t)input); + input = be16toh(input); else - input = le16toh((uint16_t)input); + input = le16toh(input); /* * Shift before conversion to avoid sign extension * of left aligned data */ input >>= info->shift; + input &= info->mask; if (info->is_signed) { - int16_t val = input; + int16_t val = (int16_t)(input << (16 - info->bits_used)) >> + (16 - info->bits_used); + printf("%05f ", ((float)val + info->offset) * info->scale); + } else { + printf("%05f ", ((float)input + info->offset) * info->scale); + } +} - val &= (1 << info->bits_used) - 1; - val = (int16_t)(val << (16 - info->bits_used)) >> - (16 - info->bits_used); - printf("%05f ", ((float)val + info->offset)*info->scale); +void print4byte(uint32_t input, struct iio_channel_info *info) +{ + /* First swap if incorrect endian */ + if (info->be) + input = be32toh(input); + else + input = le32toh(input); + + /* + * Shift before conversion to avoid sign extension + * of left aligned data + */ + input >>= info->shift; + input &= info->mask; + if (info->is_signed) { + int32_t val = (int32_t)(input << (32 - info->bits_used)) >> + (32 - info->bits_used); + printf("%05f ", ((float)val + info->offset) * info->scale); } else { - uint16_t val = input; + printf("%05f ", ((float)input + info->offset) * info->scale); + } +} - val &= (1 << info->bits_used) - 1; - printf("%05f ", ((float)val + info->offset)*info->scale); +void print8byte(uint64_t input, struct iio_channel_info *info) +{ + /* First swap if incorrect endian */ + if (info->be) + input = be64toh(input); + else + input = le64toh(input); + + /* + * Shift before conversion to avoid sign extension + * of left aligned data + */ + input >>= info->shift; + input &= info->mask; + if (info->is_signed) { + int64_t val = (int64_t)(input << (64 - info->bits_used)) >> + (64 - info->bits_used); + /* special case for timestamp */ + if (info->scale == 1.0f && info->offset == 0.0f) + printf("%" PRId64 " ", val); + else + printf("%05f ", + ((float)val + info->offset) * info->scale); + } else { + printf("%05f ", ((float)input + info->offset) * info->scale); } } + /** * process_scan() - print out the values in SI units * @data: pointer to the start of the scan @@ -108,32 +155,12 @@ void process_scan(char *data, &channels[k]); break; case 4: - if (!channels[k].is_signed) { - uint32_t val = *(uint32_t *) - (data + channels[k].location); - printf("%05f ", ((float)val + - channels[k].offset)* - channels[k].scale); - - } + print4byte(*(uint32_t *)(data + channels[k].location), + &channels[k]); break; case 8: - if (channels[k].is_signed) { - int64_t val = *(int64_t *) - (data + - channels[k].location); - if ((val >> channels[k].bits_used) & 1) - val = (val & channels[k].mask) | - ~channels[k].mask; - /* special case for timestamp */ - if (channels[k].scale == 1.0f && - channels[k].offset == 0.0f) - printf("%" PRId64 " ", val); - else - printf("%05f ", ((float)val + - channels[k].offset)* - channels[k].scale); - } + print8byte(*(uint64_t *)(data + channels[k].location), + &channels[k]); break; default: break; -- cgit v1.2.3