On Fri, Oct 27, 2017 at 05:12:17PM +0200, Juergen Fitschen wrote:
> Some AT91 hardware has no slave mode included or only limited features
> (i.e. no fifos).
>
I am wondering if it won't be better to squash this patch into the
previous one:
Without it, it seems that we can set slave_detected for the RM9200 even
if it doesn't support the slave mode.
> Signed-off-by: Juergen Fitschen <me@xxxxxx>
> ---
> drivers/i2c/busses/i2c-at91-core.c | 14 ++++++++++++--
> drivers/i2c/busses/i2c-at91.h | 5 +++++
> 2 files changed, 17 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-at91-core.c b/drivers/i2c/busses/i2c-at91-core.c
> index 3d7287c..9bf1e9d 100644
> --- a/drivers/i2c/busses/i2c-at91-core.c
> +++ b/drivers/i2c/busses/i2c-at91-core.c
> @@ -69,6 +69,7 @@ void at91_init_twi_bus(struct at91_twi_dev *dev)
> static struct at91_twi_pdata at91rm9200_config = {
> .clk_max_div = 5,
> .clk_offset = 3,
> + .slave_mode_features = 0,
> .has_unre_flag = true,
> .has_alt_cmd = false,
> .has_hold_field = false,
> @@ -77,6 +78,7 @@ static struct at91_twi_pdata at91rm9200_config = {
> static struct at91_twi_pdata at91sam9261_config = {
> .clk_max_div = 5,
> .clk_offset = 4,
> + .slave_mode_features = AT91_TWI_SM_AVAILABLE,
> .has_unre_flag = false,
> .has_alt_cmd = false,
> .has_hold_field = false,
> @@ -85,6 +87,7 @@ static struct at91_twi_pdata at91sam9261_config = {
> static struct at91_twi_pdata at91sam9260_config = {
> .clk_max_div = 7,
> .clk_offset = 4,
> + .slave_mode_features = AT91_TWI_SM_AVAILABLE,
> .has_unre_flag = false,
> .has_alt_cmd = false,
> .has_hold_field = false,
> @@ -93,6 +96,7 @@ static struct at91_twi_pdata at91sam9260_config = {
> static struct at91_twi_pdata at91sam9g20_config = {
> .clk_max_div = 7,
> .clk_offset = 4,
> + .slave_mode_features = AT91_TWI_SM_AVAILABLE,
> .has_unre_flag = false,
> .has_alt_cmd = false,
> .has_hold_field = false,
> @@ -101,6 +105,7 @@ static struct at91_twi_pdata at91sam9g20_config = {
> static struct at91_twi_pdata at91sam9g10_config = {
> .clk_max_div = 7,
> .clk_offset = 4,
> + .slave_mode_features = AT91_TWI_SM_AVAILABLE,
> .has_unre_flag = false,
> .has_alt_cmd = false,
> .has_hold_field = false,
> @@ -131,6 +136,7 @@ static const struct platform_device_id at91_twi_devtypes[] = {
> static struct at91_twi_pdata at91sam9x5_config = {
> .clk_max_div = 7,
> .clk_offset = 4,
> + .slave_mode_features = AT91_TWI_SM_AVAILABLE,
> .has_unre_flag = false,
> .has_alt_cmd = false,
> .has_hold_field = false,
> @@ -139,6 +145,7 @@ static struct at91_twi_pdata at91sam9x5_config = {
> static struct at91_twi_pdata sama5d4_config = {
> .clk_max_div = 7,
> .clk_offset = 4,
> + .slave_mode_features = AT91_TWI_SM_AVAILABLE,
> .has_unre_flag = false,
> .has_alt_cmd = false,
> .has_hold_field = true,
> @@ -147,6 +154,7 @@ static struct at91_twi_pdata sama5d4_config = {
> static struct at91_twi_pdata sama5d2_config = {
> .clk_max_div = 7,
> .clk_offset = 4,
> + .slave_mode_features = AT91_TWI_SM_AVAILABLE | AT91_TWI_SM_HAS_FIFO | AT91_TWI_SM_CAN_NACK,
> .has_unre_flag = true,
> .has_alt_cmd = true,
> .has_hold_field = true,
> @@ -219,6 +227,10 @@ static int at91_twi_probe(struct platform_device *pdev)
> if (!dev->pdata)
> return -ENODEV;
>
> + dev->slave_detected = i2c_detect_slave_mode(&pdev->dev);
> + if (dev->slave_detected && dev->pdata->slave_mode_features == 0)
> + return -EPFNOSUPPORT;
> +
> dev->base = devm_ioremap_resource(&pdev->dev, mem);
> if (IS_ERR(dev->base))
> return PTR_ERR(dev->base);
> @@ -245,8 +257,6 @@ static int at91_twi_probe(struct platform_device *pdev)
> dev->adapter.timeout = AT91_I2C_TIMEOUT;
> dev->adapter.dev.of_node = pdev->dev.of_node;
>
> - dev->slave_detected = i2c_detect_slave_mode(&pdev->dev);
> -
> if (dev->slave_detected)
> rc = at91_twi_probe_slave(pdev, phy_addr, dev);
> else
> diff --git a/drivers/i2c/busses/i2c-at91.h b/drivers/i2c/busses/i2c-at91.h
> index bb502c1..4a4fa67 100644
> --- a/drivers/i2c/busses/i2c-at91.h
> +++ b/drivers/i2c/busses/i2c-at91.h
> @@ -107,9 +107,14 @@
>
> #define AT91_TWI_VER 0x00fc /* Version Register */
>
> +#define AT91_TWI_SM_AVAILABLE BIT(0) /* Slave mode supported */
> +#define AT91_TWI_SM_CAN_NACK BIT(1) /* Can send NACKs in slave mode */
> +#define AT91_TWI_SM_HAS_FIFO BIT(2) /* Has FIFO for slave mode */
> +
I would not add AT91_TWI_SM_CAN_NACK, AT91_TWI_SM_HAS_FIFO since there
is no code relying on them. Maybe you have some plans for the future?
> struct at91_twi_pdata {
> unsigned clk_max_div;
> unsigned clk_offset;
> + unsigned slave_mode_features;
> bool has_unre_flag;
> bool has_alt_cmd;
> bool has_hold_field;
> --
> 2.7.4
>
