Re: [PATCH] iio: light: ltr501: Constify structs
From: Jonathan Cameron
Date: Sat May 02 2020 - 12:40:39 EST
On Sat, 2 May 2020 11:52:37 +0200
Rikard Falkeborn <rikard.falkeborn@xxxxxxxxx> wrote:
> Constify some data structs that are never changed. In order to do so,
> also update a couple of functions that now need to accept pointers to
> const struct instead of struct. While at it, update a few more functions
> to accept pointers to const struct instead of pointers.
>
> This allows the compiler to put more data in the code segment instead of
> the data segment, as seen by the output of the file command:
>
> Before:
> text data bss dec hex filename
> 27080 8144 192 35416 8a58 drivers/iio/light/ltr501.o
>
> After:
> text data bss dec hex filename
> 27688 7536 192 35416 8a58 drivers/iio/light/ltr501.o
> Signed-off-by: Rikard Falkeborn <rikard.falkeborn@xxxxxxxxx>
Looks sensible to me. Will leave it a few days to get Peter time to
sanity check if he wants to.
Thanks,
Jonathan
> ---
> drivers/iio/light/ltr501.c | 39 +++++++++++++++++++-------------------
> 1 file changed, 20 insertions(+), 19 deletions(-)
>
> diff --git a/drivers/iio/light/ltr501.c b/drivers/iio/light/ltr501.c
> index 0626927251bb..5a3fcb127cd2 100644
> --- a/drivers/iio/light/ltr501.c
> +++ b/drivers/iio/light/ltr501.c
> @@ -101,12 +101,12 @@ struct ltr501_gain {
> int uscale;
> };
>
> -static struct ltr501_gain ltr501_als_gain_tbl[] = {
> +static const struct ltr501_gain ltr501_als_gain_tbl[] = {
> {1, 0},
> {0, 5000},
> };
>
> -static struct ltr501_gain ltr559_als_gain_tbl[] = {
> +static const struct ltr501_gain ltr559_als_gain_tbl[] = {
> {1, 0},
> {0, 500000},
> {0, 250000},
> @@ -117,14 +117,14 @@ static struct ltr501_gain ltr559_als_gain_tbl[] = {
> {0, 10000},
> };
>
> -static struct ltr501_gain ltr501_ps_gain_tbl[] = {
> +static const struct ltr501_gain ltr501_ps_gain_tbl[] = {
> {1, 0},
> {0, 250000},
> {0, 125000},
> {0, 62500},
> };
>
> -static struct ltr501_gain ltr559_ps_gain_tbl[] = {
> +static const struct ltr501_gain ltr559_ps_gain_tbl[] = {
> {0, 62500}, /* x16 gain */
> {0, 31250}, /* x32 gain */
> {0, 15625}, /* bits X1 are for x64 gain */
> @@ -133,9 +133,9 @@ static struct ltr501_gain ltr559_ps_gain_tbl[] = {
>
> struct ltr501_chip_info {
> u8 partid;
> - struct ltr501_gain *als_gain;
> + const struct ltr501_gain *als_gain;
> int als_gain_tbl_size;
> - struct ltr501_gain *ps_gain;
> + const struct ltr501_gain *ps_gain;
> int ps_gain_tbl_size;
> u8 als_mode_active;
> u8 als_gain_mask;
> @@ -192,7 +192,7 @@ static int ltr501_match_samp_freq(const struct ltr501_samp_table *tab,
> return -EINVAL;
> }
>
> -static int ltr501_als_read_samp_freq(struct ltr501_data *data,
> +static int ltr501_als_read_samp_freq(const struct ltr501_data *data,
> int *val, int *val2)
> {
> int ret, i;
> @@ -210,7 +210,7 @@ static int ltr501_als_read_samp_freq(struct ltr501_data *data,
> return IIO_VAL_INT_PLUS_MICRO;
> }
>
> -static int ltr501_ps_read_samp_freq(struct ltr501_data *data,
> +static int ltr501_ps_read_samp_freq(const struct ltr501_data *data,
> int *val, int *val2)
> {
> int ret, i;
> @@ -266,7 +266,7 @@ static int ltr501_ps_write_samp_freq(struct ltr501_data *data,
> return ret;
> }
>
> -static int ltr501_als_read_samp_period(struct ltr501_data *data, int *val)
> +static int ltr501_als_read_samp_period(const struct ltr501_data *data, int *val)
> {
> int ret, i;
>
> @@ -282,7 +282,7 @@ static int ltr501_als_read_samp_period(struct ltr501_data *data, int *val)
> return IIO_VAL_INT;
> }
>
> -static int ltr501_ps_read_samp_period(struct ltr501_data *data, int *val)
> +static int ltr501_ps_read_samp_period(const struct ltr501_data *data, int *val)
> {
> int ret, i;
>
> @@ -321,7 +321,7 @@ static unsigned long ltr501_calculate_lux(u16 vis_data, u16 ir_data)
> return lux / 1000;
> }
>
> -static int ltr501_drdy(struct ltr501_data *data, u8 drdy_mask)
> +static int ltr501_drdy(const struct ltr501_data *data, u8 drdy_mask)
> {
> int tries = 100;
> int ret, status;
> @@ -373,7 +373,8 @@ static int ltr501_set_it_time(struct ltr501_data *data, int it)
> }
>
> /* read int time in micro seconds */
> -static int ltr501_read_it_time(struct ltr501_data *data, int *val, int *val2)
> +static int ltr501_read_it_time(const struct ltr501_data *data,
> + int *val, int *val2)
> {
> int ret, index;
>
> @@ -391,7 +392,7 @@ static int ltr501_read_it_time(struct ltr501_data *data, int *val, int *val2)
> return IIO_VAL_INT_PLUS_MICRO;
> }
>
> -static int ltr501_read_als(struct ltr501_data *data, __le16 buf[2])
> +static int ltr501_read_als(const struct ltr501_data *data, __le16 buf[2])
> {
> int ret;
>
> @@ -403,7 +404,7 @@ static int ltr501_read_als(struct ltr501_data *data, __le16 buf[2])
> buf, 2 * sizeof(__le16));
> }
>
> -static int ltr501_read_ps(struct ltr501_data *data)
> +static int ltr501_read_ps(const struct ltr501_data *data)
> {
> int ret, status;
>
> @@ -419,7 +420,7 @@ static int ltr501_read_ps(struct ltr501_data *data)
> return status;
> }
>
> -static int ltr501_read_intr_prst(struct ltr501_data *data,
> +static int ltr501_read_intr_prst(const struct ltr501_data *data,
> enum iio_chan_type type,
> int *val2)
> {
> @@ -716,7 +717,7 @@ static int ltr501_read_raw(struct iio_dev *indio_dev,
> return -EINVAL;
> }
>
> -static int ltr501_get_gain_index(struct ltr501_gain *gain, int size,
> +static int ltr501_get_gain_index(const struct ltr501_gain *gain, int size,
> int val, int val2)
> {
> int i;
> @@ -848,14 +849,14 @@ static int ltr501_write_raw(struct iio_dev *indio_dev,
> return ret;
> }
>
> -static int ltr501_read_thresh(struct iio_dev *indio_dev,
> +static int ltr501_read_thresh(const struct iio_dev *indio_dev,
> const struct iio_chan_spec *chan,
> enum iio_event_type type,
> enum iio_event_direction dir,
> enum iio_event_info info,
> int *val, int *val2)
> {
> - struct ltr501_data *data = iio_priv(indio_dev);
> + const struct ltr501_data *data = iio_priv(indio_dev);
> int ret, thresh_data;
>
> switch (chan->type) {
> @@ -1359,7 +1360,7 @@ static bool ltr501_is_volatile_reg(struct device *dev, unsigned int reg)
> }
> }
>
> -static struct regmap_config ltr501_regmap_config = {
> +static const struct regmap_config ltr501_regmap_config = {
> .name = LTR501_REGMAP_NAME,
> .reg_bits = 8,
> .val_bits = 8,