Eric Lee / smarc-ti-linux-kernel

Download as
Browse Code ยป

Commit 7ba8a04dcdfb5ebcb4985a92dfc4dc4f59510464

Authored by Lars-Peter Clausen
Committed by Jonathan Cameron
1 parent b24150e31a
Exists in master and in 20 other branches dlt-processor-sdk-linux-03.00.00.04, newt-ti-linux-3.12.y, processor-sdk-linux-01.00.00, processor-sdk-linux-02.00.01, smarc-ti-linux-3.12.10, smarc-ti-linux-3.12.y, smarc-ti-linux-3.14.y, smarc-ti-linux-3.15.y, smarc-ti-lsk-linux-4.1.y, smarct3x-processor-sdk-04.01.00.06, smarct3x-processor-sdk-linux-02.00.01, smarct3x-processor-sdk-linux-03.00.00.04, smarct4x-800-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-04.01.00.06, smarct4x-processor-sdk-linux-02.00.01, smarct4x-processor-sdk-linux-03.00.00.04, ti-linux-3.12.y, ti-linux-3.14.y, ti-linux-3.15.y, ti-lsk-linux-4.1.y

iio:adis16400: Add support for the 52.85 Hz base sampling rate 

The adis16400 and similar have two different base sampling rate available, from
which the actual sampling rate is derived. 1638 Hz and 52.85 Hz, switching to
the lower base sampling rate allows to support lower sampling rates.

This patch adds support for switching to the lower base sampling rate if the
requested sampling frequency is outside of the range which can be supported by
the higher base sampling rate.

The function which is used to read the current sampling rate already has support
for the lower sampling rate, so no changes are required there.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

Showing 1 changed file with 12 additions and 4 deletions Side-by-side Diff

drivers/iio/imu/adis16400_core.c
Diff comments   View file @ 7ba8a04
... ... @@ -92,18 +92,26 @@
92 92 static int adis16400_set_freq(struct adis16400_state *st, unsigned int freq)
93 93 {
94 94 unsigned int t;
  95 + uint8_t val = 0;
95 96  
96 97 t = 1638404 / freq;
97   - if (t > 0)
  98 + if (t >= 128) {
  99 + val |= ADIS16400_SMPL_PRD_TIME_BASE;
  100 + t = 52851 / freq;
  101 + if (t >= 128)
  102 + t = 127;
  103 + } else if (t != 0) {
98 104 t--;
99   - t &= ADIS16400_SMPL_PRD_DIV_MASK;
  105 + }
100 106  
101   - if ((t & ADIS16400_SMPL_PRD_DIV_MASK) >= 0x0A)
  107 + val |= t;
  108 +
  109 + if (t >= 0x0A || (val & ADIS16400_SMPL_PRD_TIME_BASE))
102 110 st->adis.spi->max_speed_hz = ADIS16400_SPI_SLOW;
103 111 else
104 112 st->adis.spi->max_speed_hz = ADIS16400_SPI_FAST;
105 113  
106   - return adis_write_reg_8(&st->adis, ADIS16400_SMPL_PRD, t);
  114 + return adis_write_reg_8(&st->adis, ADIS16400_SMPL_PRD, val);
107 115 }
108 116  
109 117 static ssize_t adis16400_read_frequency(struct device *dev,