On 20/06/2019 07:16:13+0000, Eugen.Hristev@xxxxxxxxxxxxx wrote:
> From: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
>
> Add new platform data support for digital filtering for i2c.
> The sama5d4, sama5d2 and sam9x60 support this feature.
>
> Signed-off-by: Eugen Hristev <eugen.hristev@xxxxxxxxxxxxx>
> ---
> drivers/i2c/busses/i2c-at91-core.c | 9 +++++++++
> drivers/i2c/busses/i2c-at91-master.c | 6 ++++++
> drivers/i2c/busses/i2c-at91.h | 4 ++++
> 3 files changed, 19 insertions(+)
>
> diff --git a/drivers/i2c/busses/i2c-at91-core.c b/drivers/i2c/busses/i2c-at91-core.c
> index a663a7a..62610af 100644
> --- a/drivers/i2c/busses/i2c-at91-core.c
> +++ b/drivers/i2c/busses/i2c-at91-core.c
> @@ -68,6 +68,7 @@ static struct at91_twi_pdata at91rm9200_config = {
> .has_unre_flag = true,
> .has_alt_cmd = false,
> .has_hold_field = false,
> + .has_dig_filtr = false,
As false is the default value, may we should avoid setting it
explicitly to keep the file size manageable.
> };
>
> static struct at91_twi_pdata at91sam9261_config = {
> @@ -76,6 +77,7 @@ static struct at91_twi_pdata at91sam9261_config = {
> .has_unre_flag = false,
> .has_alt_cmd = false,
> .has_hold_field = false,
> + .has_dig_filtr = false,
> };
>
> static struct at91_twi_pdata at91sam9260_config = {
> @@ -84,6 +86,7 @@ static struct at91_twi_pdata at91sam9260_config = {
> .has_unre_flag = false,
> .has_alt_cmd = false,
> .has_hold_field = false,
> + .has_dig_filtr = false,
> };
>
> static struct at91_twi_pdata at91sam9g20_config = {
> @@ -92,6 +95,7 @@ static struct at91_twi_pdata at91sam9g20_config = {
> .has_unre_flag = false,
> .has_alt_cmd = false,
> .has_hold_field = false,
> + .has_dig_filtr = false,
> };
>
> static struct at91_twi_pdata at91sam9g10_config = {
> @@ -100,6 +104,7 @@ static struct at91_twi_pdata at91sam9g10_config = {
> .has_unre_flag = false,
> .has_alt_cmd = false,
> .has_hold_field = false,
> + .has_dig_filtr = false,
> };
>
> static const struct platform_device_id at91_twi_devtypes[] = {
> @@ -130,6 +135,7 @@ static struct at91_twi_pdata at91sam9x5_config = {
> .has_unre_flag = false,
> .has_alt_cmd = false,
> .has_hold_field = false,
> + .has_dig_filtr = false,
> };
>
> static struct at91_twi_pdata sama5d4_config = {
> @@ -138,6 +144,7 @@ static struct at91_twi_pdata sama5d4_config = {
> .has_unre_flag = false,
> .has_alt_cmd = false,
> .has_hold_field = true,
> + .has_dig_filtr = true,
> };
>
> static struct at91_twi_pdata sama5d2_config = {
> @@ -146,6 +153,7 @@ static struct at91_twi_pdata sama5d2_config = {
> .has_unre_flag = true,
> .has_alt_cmd = true,
> .has_hold_field = true,
> + .has_dig_filtr = true,
> };
>
> static struct at91_twi_pdata sam9x60_config = {
> @@ -154,6 +162,7 @@ static struct at91_twi_pdata sam9x60_config = {
> .has_unre_flag = true,
> .has_alt_cmd = true,
> .has_hold_field = true,
> + .has_dig_filtr = true,
> };
>
> static const struct of_device_id atmel_twi_dt_ids[] = {
> diff --git a/drivers/i2c/busses/i2c-at91-master.c b/drivers/i2c/busses/i2c-at91-master.c
> index e87232f..366e90f 100644
> --- a/drivers/i2c/busses/i2c-at91-master.c
> +++ b/drivers/i2c/busses/i2c-at91-master.c
> @@ -31,12 +31,18 @@
>
> void at91_init_twi_bus_master(struct at91_twi_dev *dev)
> {
> + struct at91_twi_pdata *pdata = dev->pdata;
> +
> /* FIFO should be enabled immediately after the software reset */
> if (dev->fifo_size)
> at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_FIFOEN);
> at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_MSEN);
> at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SVDIS);
> at91_twi_write(dev, AT91_TWI_CWGR, dev->twi_cwgr_reg);
> +
> + /* enable digital filter */
> + if (pdata->has_dig_filtr)
> + at91_twi_write(dev, AT91_TWI_FILTR, AT91_TWI_FILTR_FILT);
You are enabling all those filtering features by default which mean that
if we ever need to handle them using DT, the property will be a
disabling one instead of a more logical enabling one.
--
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
