RE: [PATCH v6 6/9] mmc: dw_mmc: add device tree support

[Seungwon Jeon <tgih.jun@samsung.com>]

On Tuesday, September 18, 2012, Thomas Abraham <thomas.abraham@linaro.org> wrote:
> +#ifdef CONFIG_OF
> +/* given a slot id, find out the device node representing that slot */
> +static struct device_node *dw_mci_of_find_slot_node(struct device *dev, u8 slot)
> +{
> +	struct device_node *np;
> +	const __be32 *addr;
> +	int len;
> +
> +	if (!dev || !dev->of_node)
> +		return NULL;
> +
> +	for_each_child_of_node(dev->of_node, np) {
> +		addr = of_get_property(np, "reg", &len);
> +		if (!addr || (len < sizeof(int)))
> +			continue;
> +		if (be32_to_cpup(addr) == slot)
> +			return np;
> +	}
> +	return NULL;
> +}
> +
> +/* find out bus-width for a given slot */
> +static u32 dw_mci_of_get_bus_wd(struct device *dev, u8 slot)
> +{
> +	struct device_node *np = dw_mci_of_find_slot_node(dev, slot);
> +	u32 bus_wd = 1;
> +
> +	if (!np)
> +		return 1;
> +
> +	if (of_property_read_u32(np, "bus-width", &bus_wd))
> +		dev_err(dev, "bus-width property not found, assuming width"
> +			       " as 1\n");
> +	return bus_wd;
> +}
> +#else /* CONFIG_OF */
> +static u32 dw_mci_of_get_bus_wd(struct device *dev, u8 slot)
> +{
> +	return 1;
> +}
> +static struct device_node *dw_mci_of_find_slot_node(struct device *dev, u8 slot)
> +{
> +	return NULL;
> +}
> +#endif /* CONFIG_OF */
> +
>  static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
>  {
>  	struct mmc_host *mmc;
>  	struct dw_mci_slot *slot;
> +	u8 bus_width;
> 
>  	mmc = mmc_alloc_host(sizeof(struct dw_mci_slot), host->dev);
>  	if (!mmc)
> @@ -1782,6 +1830,7 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
>  	slot->id = id;
>  	slot->mmc = mmc;
>  	slot->host = host;
> +	host->slot[id] = slot;
> 
>  	mmc->ops = &dw_mci_ops;
>  	mmc->f_min = DIV_ROUND_UP(host->bus_hz, 510);
> @@ -1806,8 +1855,18 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
>  		mmc->caps2 = host->pdata->caps2;
> 
>  	if (host->pdata->get_bus_wd)
> -		if (host->pdata->get_bus_wd(slot->id) >= 4)
> -			mmc->caps |= MMC_CAP_4_BIT_DATA;
> +		bus_width = host->pdata->get_bus_wd(slot->id);
> +	else if (host->dev->of_node)
> +		bus_width = dw_mci_of_get_bus_wd(host->dev, slot->id);
> +	else
> +		bus_width = 1;
> +
> +	switch (bus_width) {
> +	case 8:
> +		mmc->caps |= MMC_CAP_8_BIT_DATA;
> +	case 4:
> +		mmc->caps |= MMC_CAP_4_BIT_DATA;
> +	}
> 
>  	if (host->pdata->quirks & DW_MCI_QUIRK_HIGHSPEED)
>  		mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED;
> @@ -1852,7 +1911,6 @@ static int dw_mci_init_slot(struct dw_mci *host, unsigned int id)
>  	else
>  		clear_bit(DW_MMC_CARD_PRESENT, &slot->flags);
> 
> -	host->slot[id] = slot;
>  	mmc_add_host(mmc);
> 
>  #if defined(CONFIG_DEBUG_FS)
> @@ -1944,16 +2002,74 @@ static bool mci_wait_reset(struct device *dev, struct dw_mci *host)
>  	return false;
>  }
> 
The following CONFIG_OF block can be put together in upper CONFIG_OF .

> +#ifdef CONFIG_OF
> +static struct dw_mci_of_quirks {
> +	char *quirk;
> +	int id;
> +} of_quirks[] = {
> +	{
> +		.quirk	= "supports-highspeed",
> +		.id	= DW_MCI_QUIRK_HIGHSPEED,
> +	}, {
> +		.quirk	= "broken-cd",
> +		.id	= DW_MCI_QUIRK_BROKEN_CARD_DETECTION,
> +	},
> +};
> +
> +static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
> +{
> +	struct dw_mci_board *pdata;
> +	struct device *dev = host->dev;
> +	struct device_node *np = dev->of_node;
> +	int idx;
> +
> +	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
> +	if (!pdata) {
> +		dev_err(dev, "could not allocate memory for pdata\n");
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
> +	/* find out number of slots supported */
> +	if (of_property_read_u32(dev->of_node, "num-slots",
> +				&pdata->num_slots)) {
> +		dev_info(dev, "num-slots property not found, "
> +				"assuming 1 slot is available\n");
> +		pdata->num_slots = 1;
> +	}
> +
> +	/* get quirks */
> +	for (idx = 0; idx < ARRAY_SIZE(of_quirks); idx++)
> +		if (of_get_property(np, of_quirks[idx].quirk, NULL))
> +			pdata->quirks |= of_quirks[idx].id;
> +
> +	if (of_property_read_u32(np, "fifo-depth", &pdata->fifo_depth))
> +		dev_info(dev, "fifo-depth property not found, using "
> +				"value of FIFOTH register as default\n");
> +
> +	of_property_read_u32(np, "card-detect-delay", &pdata->detect_delay_ms);
> +
> +	return pdata;
> +}
> +
> +#else /* CONFIG_OF */
> +static struct dw_mci_board *dw_mci_parse_dt(struct dw_mci *host)
> +{
> +	return ERR_PTR(-EINVAL);
> +}
> +#endif /* CONFIG_OF */
> +
>  int dw_mci_probe(struct dw_mci *host)
>  {
>  	int width, i, ret = 0;
>  	u32 fifo_size;
>  	int init_slots = 0;
> 
> -	if (!host->pdata || !host->pdata->init) {
"!host->pdata->init" is removed.
Please check it.

Thanks,
Seungwon Jeon

> -		dev_err(host->dev,
> -			"Platform data must supply init function\n");
> -		return -ENODEV;
> +	if (!host->pdata) {
> +		host->pdata = dw_mci_parse_dt(host);
> +		if (IS_ERR(host->pdata)) {
> +			dev_err(host->dev, "platform data not available\n");
> +			return -EINVAL;
> +		}
>  	}
> 
>  	if (!host->pdata->select_slot && host->pdata->num_slots > 1) {
> --
> 1.6.6.rc2
> 
> --
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