Re: [PATCH 1/3] media: i2c: ds90ub960: Convert IC specific variables to flags

[Tomi Valkeinen <tomi.valkeinen@xxxxxxxxxxxxxxxx>]

Hi,

On 30/08/2024 10:00, Alexander Shiyan wrote:
> This patch converts chip-specific variables into generic flags that
> can be used to easily add support for other chip types.
>
> Signed-off-by: Alexander Shiyan <eagle.alexander923@xxxxxxxxx>
> ---
>   drivers/media/i2c/ds90ub960.c | 48 ++++++++++++++++++++++++-----------
>   1 file changed, 33 insertions(+), 15 deletions(-)
>
> diff --git a/drivers/media/i2c/ds90ub960.c b/drivers/media/i2c/ds90ub960.c
> index ffe5f25f8647..e9f9abf439ee 100644
> --- a/drivers/media/i2c/ds90ub960.c
> +++ b/drivers/media/i2c/ds90ub960.c
> @@ -402,12 +402,18 @@
>   #define UB960_MAX_EQ_LEVEL  14
>   #define UB960_NUM_EQ_LEVELS (UB960_MAX_EQ_LEVEL - UB960_MIN_EQ_LEVEL + 1)
>   
> +enum chip_type {
> +	UB960,
> +	UB9702,
> +};
> +
> +#define FLAGS_HAS_FPDLINK4			BIT(0)
> +
>   struct ub960_hw_data {
> -	const char *model;
> +	enum chip_type chip_type;
>   	u8 num_rxports;
>   	u8 num_txports;
> -	bool is_ub9702;
> -	bool is_fpdlink4;
> +	u32 flags;

Let's drop the is_fpdlink4/FLAGS_HAS_FPDLINK4. It's only used in one 
place, and just checking for the model == UB9702 is fine.

While you're at this, can you go through the code for ifs/selects for 
chip_type, and change the code so that we don't have plain "else" blocks 
there. I.e. in each chip_type test we would be explicitly testing for 
matching chip types, and _not_ do things like:

if (ub960)
	xyz-for-ub960;
else
	must-be-ub9702;

Also, with the above change, and adding UB954, I wonder if it would make 
the code simpler if we added a "chip family" property. The UB960 & UB954 
are clearly part of the same family, whereas UB9702 (and other FPD-Link 
4 desers which the driver doesn't support) are another. As we don't have 
a good name for them, maybe just FAMILY_FPD3 and FAMILY_FPD4.

 Tomi

>   };
>   
>   enum ub960_rxport_mode {
> @@ -1654,7 +1660,7 @@ static int ub960_rxport_add_serializer(struct ub960_data *priv, u8 nport)
>   
>   	ser_pdata->port = nport;
>   	ser_pdata->atr = priv->atr;
> -	if (priv->hw_data->is_ub9702)
> +	if (priv->hw_data->chip_type == UB9702)
>   		ser_pdata->bc_rate = ub960_calc_bc_clk_rate_ub9702(priv, rxport);
>   	else
>   		ser_pdata->bc_rate = ub960_calc_bc_clk_rate_ub960(priv, rxport);
> @@ -1785,7 +1791,7 @@ static int ub960_init_tx_ports(struct ub960_data *priv)
>   
>   	ub960_write(priv, UB960_SR_CSI_PLL_CTL, speed_select);
>   
> -	if (priv->hw_data->is_ub9702) {
> +	if (priv->hw_data->chip_type == UB9702) {
>   		ub960_write(priv, UB960_SR_CSI_PLL_DIV, pll_div);
>   
>   		switch (priv->tx_data_rate) {
> @@ -2140,7 +2146,7 @@ static int ub960_init_rx_ports(struct ub960_data *priv)
>   		if (!rxport)
>   			continue;
>   
> -		if (priv->hw_data->is_ub9702)
> +		if (priv->hw_data->chip_type == UB9702)
>   			ub960_init_rx_port_ub9702(priv, rxport);
>   		else
>   			ub960_init_rx_port_ub960(priv, rxport);
> @@ -2509,7 +2515,7 @@ static int ub960_configure_ports_for_streaming(struct ub960_data *priv,
>   
>   		case RXPORT_MODE_CSI2_SYNC:
>   		case RXPORT_MODE_CSI2_NONSYNC:
> -			if (!priv->hw_data->is_ub9702) {
> +			if (priv->hw_data->chip_type != UB9702) {
>   				/* Map all VCs from this port to the same VC */
>   				ub960_rxport_write(priv, nport, UB960_RR_CSI_VC_MAP,
>   						   (vc << UB960_RR_CSI_VC_MAP_SHIFT(3)) |
> @@ -3217,7 +3223,8 @@ ub960_parse_dt_rxport_link_properties(struct ub960_data *priv,
>   		return -EINVAL;
>   	}
>   
> -	if (!priv->hw_data->is_fpdlink4 && cdr_mode == RXPORT_CDR_FPD4) {
> +	if (!(priv->hw_data->flags & FLAGS_HAS_FPDLINK4) &&
> +	    (cdr_mode == RXPORT_CDR_FPD4)) {
>   		dev_err(dev, "rx%u: FPD-Link 4 CDR not supported\n", nport);
>   		return -EINVAL;
>   	}
> @@ -3796,6 +3803,7 @@ static int ub960_get_hw_resources(struct ub960_data *priv)
>   static int ub960_enable_core_hw(struct ub960_data *priv)
>   {
>   	struct device *dev = &priv->client->dev;
> +	const char *model;
>   	u8 rev_mask;
>   	int ret;
>   	u8 dev_sts;
> @@ -3830,8 +3838,19 @@ static int ub960_enable_core_hw(struct ub960_data *priv)
>   		goto err_pd_gpio;
>   	}
>   
> -	dev_dbg(dev, "Found %s (rev/mask %#04x)\n", priv->hw_data->model,
> -		rev_mask);
> +	switch (priv->hw_data->chip_type) {
> +	case UB960:
> +		model = "UB960";
> +		break;
> +	case UB9702:
> +		model = "UB9702";
> +		break;
> +	default:
> +		model = "Unknown";
> +		break;
> +	};
> +
> +	dev_dbg(dev, "Found %s (rev/mask %#04x)\n", model, rev_mask);
>   
>   	ret = ub960_read(priv, UB960_SR_DEVICE_STS, &dev_sts);
>   	if (ret)
> @@ -3851,7 +3870,7 @@ static int ub960_enable_core_hw(struct ub960_data *priv)
>   		goto err_pd_gpio;
>   
>   	/* release GPIO lock */
> -	if (priv->hw_data->is_ub9702) {
> +	if (priv->hw_data->chip_type == UB9702) {
>   		ret = ub960_update_bits(priv, UB960_SR_RESET,
>   					UB960_SR_RESET_GPIO_LOCK_RELEASE,
>   					UB960_SR_RESET_GPIO_LOCK_RELEASE);
> @@ -4013,17 +4032,16 @@ static void ub960_remove(struct i2c_client *client)
>   }
>   
>   static const struct ub960_hw_data ds90ub960_hw = {
> -	.model = "ub960",
> +	.chip_type = UB960,
>   	.num_rxports = 4,
>   	.num_txports = 2,
>   };
>   
>   static const struct ub960_hw_data ds90ub9702_hw = {
> -	.model = "ub9702",
> +	.chip_type = UB9702,
>   	.num_rxports = 4,
>   	.num_txports = 2,
> -	.is_ub9702 = true,
> -	.is_fpdlink4 = true,
> +	.flags = FLAGS_HAS_FPDLINK4,
>   };
>   
>   static const struct i2c_device_id ub960_id[] = {