Thread (18 messages) 18 messages, 2 authors, 2012-09-21

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

From: Seungwon Jeon <hidden>
Date: 2012-09-19 13:39:53
Also in: linux-mmc, linux-samsung-soc

On Tuesday, September 18, 2012, Thomas Abraham [off-list ref] wrote:
quoted hunk ↗ jump to hunk
+#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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