Re: [PATCH 09/10] iio: imu: kmx61: Drop odr_bits from kmx61_samp_freq_table

From: Jonathan Cameron
Date: Sun Jan 04 2015 - 05:55:43 EST


On 01/01/15 13:53, Hartmut Knaack wrote:
> Daniel Baluta schrieb am 23.12.2014 um 14:22:
>> odr_bits values are between 0 and 11, so we can use the index
>> in kmx61_samp_freq_table instead of odr_bits structure member.
> Basically looking good, but I would feel more comfortable to check
> against the boundaries of the table. Please see inline.
>
>>
>> Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx>
>> ---
>> drivers/iio/imu/kmx61.c | 64 ++++++++++++++++++++-----------------------------
>> 1 file changed, 26 insertions(+), 38 deletions(-)
>>
>> diff --git a/drivers/iio/imu/kmx61.c b/drivers/iio/imu/kmx61.c
>> index eb3900e..98369eb 100644
>> --- a/drivers/iio/imu/kmx61.c
>> +++ b/drivers/iio/imu/kmx61.c
>> @@ -169,19 +169,18 @@ u16 kmx61_uscale_table[] = {9582, 19163, 38326};
>> static const struct {
>> int val;
>> int val2;
>> - u8 odr_bits;
>> -} kmx61_samp_freq_table[] = { {12, 500000, 0x00},
>> - {25, 0, 0x01},
>> - {50, 0, 0x02},
>> - {100, 0, 0x03},
>> - {200, 0, 0x04},
>> - {400, 0, 0x05},
>> - {800, 0, 0x06},
>> - {1600, 0, 0x07},
>> - {0, 781000, 0x08},
>> - {1, 563000, 0x09},
>> - {3, 125000, 0x0A},
>> - {6, 250000, 0x0B} };
>> +} kmx61_samp_freq_table[] = { {12, 500000},
>> + {25, 0},
>> + {50, 0},
>> + {100, 0},
>> + {200, 0},
>> + {400, 0},
>> + {800, 0},
>> + {1600, 0},
>> + {0, 781000},
>> + {1, 563000},
>> + {3, 125000},
>> + {6, 250000} };
>>
>> static const struct {
>> int val;
>> @@ -302,24 +301,10 @@ static int kmx61_convert_freq_to_bit(int val, int val2)
>> for (i = 0; i < ARRAY_SIZE(kmx61_samp_freq_table); i++)
>> if (val == kmx61_samp_freq_table[i].val &&
>> val2 == kmx61_samp_freq_table[i].val2)
>> - return kmx61_samp_freq_table[i].odr_bits;
>> - return -EINVAL;
>> -}
>> -
>> -static int kmx61_convert_bit_to_freq(u8 odr_bits, int *val, int *val2)
>> -{
>> - int i;
>> -
>> - for (i = 0; i < ARRAY_SIZE(kmx61_samp_freq_table); i++)
>> - if (odr_bits == kmx61_samp_freq_table[i].odr_bits) {
>> - *val = kmx61_samp_freq_table[i].val;
>> - *val2 = kmx61_samp_freq_table[i].val2;
>> - return 0;
>> - }
>> + return i;
>> return -EINVAL;
>> }
>>
>> -
>> static int kmx61_convert_wake_up_odr_to_bit(int val, int val2)
>> {
>> int i;
>> @@ -478,7 +463,7 @@ static int kmx61_set_odr(struct kmx61_data *data, int val, int val2, u8 device)
>>
>> static int kmx61_get_odr(struct kmx61_data *data, int *val, int *val2,
>> u8 device)
>> -{ int i;
>> +{
>> u8 lodr_bits;
>>
>> if (device & KMX61_ACC)
>> @@ -490,13 +475,13 @@ static int kmx61_get_odr(struct kmx61_data *data, int *val, int *val2,
>> else
>> return -EINVAL;
>>
>> - for (i = 0; i < ARRAY_SIZE(kmx61_samp_freq_table); i++)
>> - if (lodr_bits == kmx61_samp_freq_table[i].odr_bits) {
>> - *val = kmx61_samp_freq_table[i].val;
>> - *val2 = kmx61_samp_freq_table[i].val2;
>> - return 0;
>> - }
>> - return -EINVAL;
>> + if (lodr_bits > 0xB)
> Since we use it as an index, I regard it safer to check against
> ARRAY_SIZE(kmx61_samp_freq_table) rather than a fix value.
Makes sense to me as well - though obviously ARRAY_SIZE(kmx61_samp_freq_table) is
0xC (12) rather than 0xB (11) so you'll need a minus 1

I'll leave this one for a new spin.
>
>> + return -EINVAL;
>> +
>> + *val = kmx61_samp_freq_table[lodr_bits].val;
>> + *val2 = kmx61_samp_freq_table[lodr_bits].val2;
>> +
>> + return 0;
>> }
>>
>> static int kmx61_set_range(struct kmx61_data *data, u8 range)
>> @@ -580,8 +565,11 @@ static int kmx61_chip_init(struct kmx61_data *data)
>> }
>> data->odr_bits = ret;
>>
>> - /* set output data rate for wake up (motion detection) function */
>> - ret = kmx61_convert_bit_to_freq(data->odr_bits, &val, &val2);
>> + /*
>> + * set output data rate for wake up (motion detection) function
>> + * to match data rate for accelerometer sampling
>> + */
>> + ret = kmx61_get_odr(data, &val, &val2, KMX61_ACC);
>> if (ret < 0)
>> return ret;
>>
>>
>

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