Re: [PATCH 2/3] iio: adc: stm32: remove const channel names definition

From: Jonathan Cameron
Date: Sat Oct 21 2017 - 13:59:20 EST


On Tue, 17 Oct 2017 15:15:44 +0200
Fabrice Gasnier <fabrice.gasnier@xxxxxx> wrote:

> Remove const array that defines channels. Build channels definition
> at probe time, when initializing channels (only for requested ones).
> This will ease adding differential channels support.
>
> Signed-off-by: Fabrice Gasnier <fabrice.gasnier@xxxxxx>
Looks good to me.
> ---
> drivers/iio/adc/stm32-adc.c | 66 ++++++++++-----------------------------------
> 1 file changed, 14 insertions(+), 52 deletions(-)
>
> diff --git a/drivers/iio/adc/stm32-adc.c b/drivers/iio/adc/stm32-adc.c
> index 4df32cf..c95e6f7 100644
> --- a/drivers/iio/adc/stm32-adc.c
> +++ b/drivers/iio/adc/stm32-adc.c
> @@ -153,6 +153,8 @@ enum stm32h7_adc_dmngt {
> /* BOOST bit must be set on STM32H7 when ADC clock is above 20MHz */
> #define STM32H7_BOOST_CLKRATE 20000000UL
>
> +#define STM32_ADC_CH_MAX 20 /* max number of channels */
> +#define STM32_ADC_CH_SZ 5 /* max channel name size */
> #define STM32_ADC_MAX_SQ 16 /* SQ1..SQ16 */
> #define STM32_ADC_MAX_SMP 7 /* SMPx range is [0..7] */
> #define STM32_ADC_TIMEOUT_US 100000
> @@ -300,6 +302,7 @@ struct stm32_adc_cfg {
> * @pcsel bitmask to preselect channels on some devices
> * @smpr_val: sampling time settings (e.g. smpr1 / smpr2)
> * @cal: optional calibration data on some devices
> + * @chan_name: channel name array
> */
> struct stm32_adc {
> struct stm32_adc_common *common;
> @@ -321,69 +324,28 @@ struct stm32_adc {
> u32 pcsel;
> u32 smpr_val[2];
> struct stm32_adc_calib cal;
> -};
> -
> -/**
> - * struct stm32_adc_chan_spec - specification of stm32 adc channel
> - * @type: IIO channel type
> - * @channel: channel number (single ended)
> - * @name: channel name (single ended)
> - */
> -struct stm32_adc_chan_spec {
> - enum iio_chan_type type;
> - int channel;
> - const char *name;
> + char chan_name[STM32_ADC_CH_MAX][STM32_ADC_CH_SZ];
> };
>
> /**
> * struct stm32_adc_info - stm32 ADC, per instance config data
> - * @channels: Reference to stm32 channels spec
> * @max_channels: Number of channels
> * @resolutions: available resolutions
> * @num_res: number of available resolutions
> */
> struct stm32_adc_info {
> - const struct stm32_adc_chan_spec *channels;
> int max_channels;
> const unsigned int *resolutions;
> const unsigned int num_res;
> };
>
> -/*
> - * Input definitions common for all instances:
> - * stm32f4 can have up to 16 channels
> - * stm32h7 can have up to 20 channels
> - */
> -static const struct stm32_adc_chan_spec stm32_adc_channels[] = {
> - { IIO_VOLTAGE, 0, "in0" },
> - { IIO_VOLTAGE, 1, "in1" },
> - { IIO_VOLTAGE, 2, "in2" },
> - { IIO_VOLTAGE, 3, "in3" },
> - { IIO_VOLTAGE, 4, "in4" },
> - { IIO_VOLTAGE, 5, "in5" },
> - { IIO_VOLTAGE, 6, "in6" },
> - { IIO_VOLTAGE, 7, "in7" },
> - { IIO_VOLTAGE, 8, "in8" },
> - { IIO_VOLTAGE, 9, "in9" },
> - { IIO_VOLTAGE, 10, "in10" },
> - { IIO_VOLTAGE, 11, "in11" },
> - { IIO_VOLTAGE, 12, "in12" },
> - { IIO_VOLTAGE, 13, "in13" },
> - { IIO_VOLTAGE, 14, "in14" },
> - { IIO_VOLTAGE, 15, "in15" },
> - { IIO_VOLTAGE, 16, "in16" },
> - { IIO_VOLTAGE, 17, "in17" },
> - { IIO_VOLTAGE, 18, "in18" },
> - { IIO_VOLTAGE, 19, "in19" },
> -};
> -
> static const unsigned int stm32f4_adc_resolutions[] = {
> /* sorted values so the index matches RES[1:0] in STM32F4_ADC_CR1 */
> 12, 10, 8, 6,
> };
>
> +/* stm32f4 can have up to 16 channels */
> static const struct stm32_adc_info stm32f4_adc_info = {
> - .channels = stm32_adc_channels,
> .max_channels = 16,
> .resolutions = stm32f4_adc_resolutions,
> .num_res = ARRAY_SIZE(stm32f4_adc_resolutions),
> @@ -394,9 +356,9 @@ struct stm32_adc_info {
> 16, 14, 12, 10, 8,
> };
>
> +/* stm32h7 can have up to 20 channels */
> static const struct stm32_adc_info stm32h7_adc_info = {
> - .channels = stm32_adc_channels,
> - .max_channels = 20,
> + .max_channels = STM32_ADC_CH_MAX,
> .resolutions = stm32h7_adc_resolutions,
> .num_res = ARRAY_SIZE(stm32h7_adc_resolutions),
> };
> @@ -1628,15 +1590,16 @@ static void stm32_adc_smpr_init(struct stm32_adc *adc, int channel, u32 smp_ns)
> }
>
> static void stm32_adc_chan_init_one(struct iio_dev *indio_dev,
> - struct iio_chan_spec *chan,
> - const struct stm32_adc_chan_spec *channel,
> + struct iio_chan_spec *chan, u32 val,
> int scan_index, u32 smp)
> {
> struct stm32_adc *adc = iio_priv(indio_dev);
> + char *name = adc->chan_name[val];
>
> - chan->type = channel->type;
> - chan->channel = channel->channel;
> - chan->datasheet_name = channel->name;
> + chan->type = IIO_VOLTAGE;
> + chan->channel = val;
> + snprintf(name, STM32_ADC_CH_SZ, "in%d", val);
> + chan->datasheet_name = name;
> chan->scan_index = scan_index;
> chan->indexed = 1;
> chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW);
> @@ -1699,8 +1662,7 @@ static int stm32_adc_chan_of_init(struct iio_dev *indio_dev)
> scan_index, &smp);
>
> stm32_adc_chan_init_one(indio_dev, &channels[scan_index],
> - &adc_info->channels[val],
> - scan_index, smp);
> + val, scan_index, smp);
> scan_index++;
> }
>