On Thu, 16 May 2019 17:32:06 +0300
Beniamin Bia <beniamin.bia@xxxxxxxxxx> wrote:
> In order to support AD7616 software mode, the spi register access must be
> added and the calculation of registers address must be generic.
> The length of address and bit which specifies the read/write operation is
> different for every device, that is why it was made generic.
>
> Signed-off-by: Beniamin Bia <beniamin.bia@xxxxxxxxxx>
The break up patches has ended up a little odd. This one introduced unused
functions for example. Probably best to merge this and the next patch.
As a potential follow up, could this driver just use a 16 bit word
length and avoid some of the endian handling? (this might also fix
the casting issues).
However, there are some nasty casts in here that sparse is unhappy about.
I would definitely like those cleaned up before we add more of them.
If changing to 16bit SPI words doesn't do the job, then perhaps
we have to have a be16 version of data (as a union to avoid more
space usage).
Thanks,
Jonathan
> ---
> drivers/iio/adc/ad7606.c | 60 ++++++++++++++++++++++++++++++++++++++++
> drivers/iio/adc/ad7606.h | 2 ++
> 2 files changed, 62 insertions(+)
>
> diff --git a/drivers/iio/adc/ad7606.c b/drivers/iio/adc/ad7606.c
> index aba0fd123a51..6df81117cacc 100644
> --- a/drivers/iio/adc/ad7606.c
> +++ b/drivers/iio/adc/ad7606.c
> @@ -25,6 +25,8 @@
> #include <linux/iio/triggered_buffer.h>
> #include <linux/iio/trigger_consumer.h>
>
> +#include <linux/spi/spi.h>
> +
> #include "ad7606.h"
>
> /*
> @@ -43,6 +45,11 @@ static const unsigned int ad7616_oversampling_avail[8] = {
> 1, 2, 4, 8, 16, 32, 64, 128,
> };
>
> +static int ad7616_spi_rd_wr_cmd(int addr, char isWriteOp)
> +{
> + return ((addr & 0x7F) << 1) | ((isWriteOp & 0x1) << 7);
> +}
> +
> static int ad7606_reset(struct ad7606_state *st)
> {
> if (st->gpio_reset) {
> @@ -55,6 +62,59 @@ static int ad7606_reset(struct ad7606_state *st)
> return -ENODEV;
> }
>
> +static int ad7606_spi_reg_read(struct ad7606_state *st, unsigned int addr)
> +{
> + struct spi_device *spi = to_spi_device(st->dev);
> + struct spi_transfer t[] = {
> + {
> + .tx_buf = &st->data[0],
> + .len = 2,
> + .cs_change = 0,
> + }, {
> + .rx_buf = &st->data[1],
> + .len = 2,
> + },
> + };
> + int ret;
> +
> + st->data[0] = cpu_to_be16(st->chip_info->spi_rd_wr_cmd(addr, 0) << 8);
> +
> + ret = spi_sync_transfer(spi, t, ARRAY_SIZE(t));
> + if (ret < 0)
> + return ret;
> +
> + return be16_to_cpu(st->data[1]);
> +}
> +
> +static int ad7606_spi_reg_write(struct ad7606_state *st,
> + unsigned int addr,
> + unsigned int val)
> +{
> + struct spi_device *spi = to_spi_device(st->dev);
> +
> + st->data[0] = cpu_to_be16((st->chip_info->spi_rd_wr_cmd(addr, 1) << 8) |
> + (val & 0x1FF));
> +
> + return spi_write(spi, &st->data[0], sizeof(st->data[0]));
> +}
> +
> +static int ad7606_spi_write_mask(struct ad7606_state *st,
> + unsigned int addr,
> + unsigned long mask,
> + unsigned int val)
> +{
> + int readval;
> +
> + readval = ad7606_spi_reg_read(st, addr);
> + if (readval < 0)
> + return readval;
> +
> + readval &= ~mask;
> + readval |= val;
> +
> + return ad7606_spi_reg_write(st, addr, readval);
> +}
> +
> static int ad7606_read_samples(struct ad7606_state *st)
> {
> unsigned int num = st->chip_info->num_channels;
> diff --git a/drivers/iio/adc/ad7606.h b/drivers/iio/adc/ad7606.h
> index d8a509c2c428..dfc60af9b8ac 100644
> --- a/drivers/iio/adc/ad7606.h
> +++ b/drivers/iio/adc/ad7606.h
> @@ -16,6 +16,7 @@
> * oversampling ratios.
> * @oversampling_num number of elements stored in oversampling_avail array
> * @os_req_reset some devices require a reset to update oversampling
> + * @spi_rd_wr_cmd pointer to the function which calculates the spi address
> * @write_scale_sw pointer to the function which writes the scale via spi
> in software mode
> * @write_os_sw pointer to the function which writes the os via spi
> @@ -29,6 +30,7 @@ struct ad7606_chip_info {
> const unsigned int *oversampling_avail;
> unsigned int oversampling_num;
> bool os_req_reset;
> + int (*spi_rd_wr_cmd)(int addr, char isWriteOp);
> int (*write_scale_sw)(struct iio_dev *indio_dev, int ch, int val);
> int (*write_os_sw)(struct iio_dev *indio_dev, int val);
> int (*sw_mode_config)(struct iio_dev *indio_dev);
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