[PATCH v3 5/6] mmc: dw_mmc: add device tree support

[Thomas Abraham <thomas.abraham@linaro.org>]

Add device tree based discovery support.

Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
---
 .../devicetree/bindings/mmc/synposis-dw-mshc.txt   |  108 +++++++++++
 drivers/mmc/host/dw_mmc-pltfm.c                    |   24 +++
 drivers/mmc/host/dw_mmc.c                          |  201 +++++++++++++++++++-
 drivers/mmc/host/dw_mmc.h                          |    9 +
 include/linux/mmc/dw_mmc.h                         |    2 +
 5 files changed, 338 insertions(+), 6 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/mmc/synposis-dw-mshc.txt

diff --git a/Documentation/devicetree/bindings/mmc/synposis-dw-mshc.txt b/Documentation/devicetree/bindings/mmc/synposis-dw-mshc.txt
new file mode 100644
index 0000000..3acd6c9
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/synposis-dw-mshc.txt
@@ -0,0 +1,108 @@
+* Synopsis Designware Mobile Storage Host Controller
+
+The Synopsis designware mobile storage host controller is used to interface
+a SoC with storage medium such as eMMC or SD/MMC cards.
+
+Required Properties:
+
+* compatible: should be one of the following
+	- snps,dw-mshc: for controllers compliant with synopsis dw-mshc.
+
+* reg: physical base address of the dw-mshc controller and size of its memory
+  region.
+
+* interrupts: interrupt specifier for the controller. The format and value of
+  the interrupt specifier depends on the interrupt parent for the controller.
+
+* #address-cells: should be 1.
+
+* #size-cells: should be 0.
+
+# Slots: The slot specific information are contained within child-nodes with
+  each child-node representing a supported slot. There should be atleast one
+  child node representing a card slot. The name of the child node representing
+  the slot is recommended to be slot@n where n is the unique number of the slot
+  connnected to the controller. The following are optional properties which
+  can be included in the slot child node.
+
+	* reg: specifies the physical slot number. The valid values of this
+	  property is 0 to (num-slots -1), where num-slots is the value
+	  specified by the num-slots property.
+
+	* bus-width: specifies the width of the data bus connected from the
+	  controller to the card slot. The value should be 1, 4 or 8. In case
+	  this property is not specified, a default value of 1 is assumed for
+	  this property.
+
+	* cd-gpios: specifies the card detect gpio line. The format of the
+	  gpio specifier depends on the gpio controller.
+
+	* wp-gpios: specifies the write protect gpio line. The format of the
+	  gpio specifier depends on the gpio controller.
+
+	* gpios: specifies a list of gpios used for command, clock and data
+	  bus. The first gpio is the command line and the second gpio is the
+	  clock line. The rest of the gpios (depending on the bus-width
+	  property) are the data lines in no particular order. The format of
+	  the gpio specifier depends on the gpio controller.
+
+Optional properties:
+
+* num-slots: specifies the number of slots supported by the controller.
+  The number of physical slots actually used could be equal or less than the
+  value specified by num-slots. If this property is not specified, the value
+  of num-slot property is assumed to be 1.
+
+* fifo-depth: The maximum size of the tx/rx fifo's. If this property is not
+  specified, the default value of the fifo size is determined from the
+  controller registers.
+
+* card-detect-delay: Delay in milli-seconds before detecting card after card
+  insert event. The default value is 0.
+
+* supports-highspeed: Enables support for high speed cards (upto 50MHz)
+
+* card-detection-broken: The card detection functionality is not available on
+  any of the slots.
+
+* no-write-protect: The write protect pad of the controller is not connected
+  to the write protect pin on the slot.
+
+Aliases:
+
+- All the MSHC controller nodes should be represented in the aliases node using
+  the following format 'mshc{n}' where n is a unique number for the alias.
+
+
+Example:
+
+  The MSHC controller node can be split into two portions, SoC specific and
+  board specific portions as listed below.
+
+	dwmmc0@12200000 {
+		compatible = "snps,dw-mshc";
+		reg = <0x12200000 0x1000>;
+		interrupts = <0 75 0>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+	};
+
+	dwmmc0@12200000 {
+		num-slots = <1>;
+		supports-highspeed;
+		card-detection-broken;
+		no-write-protect;
+		fifo-depth = <0x80>;
+		card-detect-delay = <200>;
+
+		slot@0 {
+			reg = <0>;
+			bus-width = <8>;
+			cd-gpios = <&gpc0 2 2 3 3>;
+			gpios = <&gpc0 0 2 0 3>, <&gpc0 1 2 0 3>,
+				<&gpc1 0 2 3 3>, <&gpc1 1 2 3 3>,
+				<&gpc1 2 2 3 3>, <&gpc1 3 2 3 3>,
+				<&gpc0 3 2 3 3>, <&gpc0 4 2 3 3>,
+				<&gpc0 5 2 3 3>, <&gpc0 6 2 3 3>;
+		};
+	};
diff --git a/drivers/mmc/host/dw_mmc-pltfm.c b/drivers/mmc/host/dw_mmc-pltfm.c
index 9a63299..8d24f6d 100644
--- a/drivers/mmc/host/dw_mmc-pltfm.c
+++ b/drivers/mmc/host/dw_mmc-pltfm.c
@@ -19,8 +19,24 @@
 #include <linux/mmc/host.h>
 #include <linux/mmc/mmc.h>
 #include <linux/mmc/dw_mmc.h>
+#include <linux/of.h>
 #include "dw_mmc.h"
 
+#ifdef CONFIG_OF
+static struct dw_mci_drv_data synopsis_drv_data = {
+	.ctrl_type	= DW_MCI_TYPE_SYNOPSIS,
+};
+
+static const struct of_device_id dw_mci_pltfm_match[] = {
+	{ .compatible = "snps,dw-mshc",
+			.data = (void *)&synopsis_drv_data, },
+	{},
+};
+MODULE_DEVICE_TABLE(of, dw_mci_pltfm_match);
+#else
+static const struct of_device_id dw_mci_pltfm_match[];
+#endif
+
 static int dw_mci_pltfm_probe(struct platform_device *pdev)
 {
 	struct dw_mci *host;
@@ -51,6 +67,13 @@ static int dw_mci_pltfm_probe(struct platform_device *pdev)
 	if (!host->regs)
 		goto err_free;
 	platform_set_drvdata(pdev, host);
+
+	if (pdev->dev.of_node) {
+		const struct of_device_id *match;
+		match = of_match_node(dw_mci_pltfm_match, pdev->dev.of_node);
+		host->drv_data = match->data;
+	}
+
 	ret = dw_mci_probe(host);
 	if (ret)
 		goto err_out;
@@ -111,6 +134,7 @@ static struct platform_driver dw_mci_pltfm_driver = {
 	.remove		= __exit_p(dw_mci_pltfm_remove),
 	.driver		= {
 		.name		= "dw_mmc",
+		.of_match_table	= of_match_ptr(dw_mci_pltfm_match),
 		.pm		= &dw_mci_pltfm_pmops,
 	},
 };
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 075f89d..3bc276d 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -33,9 +33,13 @@
 #include <linux/bitops.h>
 #include <linux/regulator/consumer.h>
 #include <linux/workqueue.h>
+#include <linux/of.h>
+#include <linux/of_gpio.h>
 
 #include "dw_mmc.h"
 
+#define NUM_PINS(x) (x + 2)
+
 /* Common flag combinations */
 #define DW_MCI_DATA_ERROR_FLAGS	(SDMMC_INT_DTO | SDMMC_INT_DCRC | \
 				 SDMMC_INT_HTO | SDMMC_INT_SBE  | \
@@ -86,6 +90,8 @@ struct idmac_desc {
 struct dw_mci_slot {
 	struct mmc_host		*mmc;
 	struct dw_mci		*host;
+	int			wp_gpio;
+	int			cd_gpio;
 
 	u32			ctype;
 
@@ -1762,10 +1768,106 @@ static void dw_mci_work_routine_card(struct work_struct *work)
 	}
 }
 
+#ifdef CONFIG_OF
+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;
+}
+
+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;
+}
+
+static int dw_mci_of_setup_bus(struct dw_mci *host, u8 slot, u32 bus_wd)
+{
+	struct device_node *np = dw_mci_of_find_slot_node(host->dev, slot);
+	int idx, gpio, ret;
+
+	if (!np)
+		return -EINVAL;
+
+	for (idx = 0; idx < NUM_PINS(bus_wd); idx++) {
+		gpio = of_get_gpio(np, idx);
+		if (!gpio_is_valid(gpio)) {
+			dev_err(host->dev, "invalid gpio: %d\n", gpio);
+			return -EINVAL;
+		}
+
+		ret = devm_gpio_request(host->dev, gpio, "dw-mci-bus");
+		if (ret) {
+			dev_err(host->dev, "gpio [%d] request failed\n", gpio);
+			return -EBUSY;
+		}
+	}
+
+	host->slot[slot]->wp_gpio = -1;
+	gpio = of_get_named_gpio(np, "wp-gpios", 0);
+	if (!gpio_is_valid(gpio)) {
+		dev_info(host->dev, "wp gpio not available");
+	} else {
+		ret = devm_gpio_request(host->dev, gpio, "dw-mci-wp");
+		if (ret)
+			dev_info(host->dev, "gpio [%d] request failed\n",
+						gpio);
+		else
+			host->slot[slot]->wp_gpio = gpio;
+	}
+
+	host->slot[slot]->cd_gpio = -1;
+	gpio = of_get_named_gpio(np, "cd-gpios", 0);
+	if (!gpio_is_valid(gpio)) {
+		dev_info(host->dev, "cd gpio not available");
+	} else {
+		ret = devm_gpio_request(host->dev, gpio, "dw-mci-cd");
+		if (ret)
+			dev_err(host->dev, "gpio [%d] request failed\n", gpio);
+		else
+			host->slot[slot]->cd_gpio = gpio;
+	}
+
+	return 0;
+}
+#else /* CONFIG_OF */
+static u32 dw_mci_of_get_bus_wd(struct device *dev, u8 slot)
+{
+	return 1;
+}
+
+static int dw_mci_of_setup_bus(struct dw_mci *host, u8 slot, u32 bus_wd)
+{
+	return -EINVAL;
+}
+#endif /* CONFIG_OF */
+
 static int __init dw_mci_init_slot(struct dw_mci *host, unsigned int id)
 {
 	struct mmc_host *mmc;
 	struct dw_mci_slot *slot;
+	int ctrl_id, ret;
 
 	mmc = mmc_alloc_host(sizeof(struct dw_mci_slot), host->dev);
 	if (!mmc)
@@ -1775,6 +1877,7 @@ static int __init 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);
@@ -1795,12 +1898,33 @@ static int __init dw_mci_init_slot(struct dw_mci *host, unsigned int id)
 	if (host->pdata->caps)
 		mmc->caps = host->pdata->caps;
 
+	if (host->dev->of_node) {
+		ctrl_id = of_alias_get_id(host->dev->of_node, "mshc");
+		if (ctrl_id < 0)
+			ctrl_id = 0;
+	}
+	if (host->drv_data->caps)
+		mmc->caps |= host->drv_data->caps[ctrl_id];
+
 	if (host->pdata->caps2)
 		mmc->caps2 = host->pdata->caps2;
 
-	if (host->pdata->get_bus_wd)
+	if (host->pdata->get_bus_wd) {
 		if (host->pdata->get_bus_wd(slot->id) >= 4)
 			mmc->caps |= MMC_CAP_4_BIT_DATA;
+	} else if (host->dev->of_node) {
+		unsigned int bus_width;
+		bus_width = dw_mci_of_get_bus_wd(host->dev, slot->id);
+		switch (bus_width) {
+		case 8:
+			mmc->caps |= MMC_CAP_8_BIT_DATA;
+		case 4:
+			mmc->caps |= MMC_CAP_4_BIT_DATA;
+		}
+		ret = dw_mci_of_setup_bus(host, slot->id, bus_width);
+		if (ret)
+			goto err_setup_bus;
+	}
 
 	if (host->pdata->quirks & DW_MCI_QUIRK_HIGHSPEED)
 		mmc->caps |= MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED;
@@ -1845,7 +1969,6 @@ static int __init 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)
@@ -1862,6 +1985,10 @@ static int __init dw_mci_init_slot(struct dw_mci *host, unsigned int id)
 	queue_work(host->card_workqueue, &host->card_work);
 
 	return 0;
+
+err_setup_bus:
+	mmc_free_host(mmc);
+	return -EINVAL;
 }
 
 static void dw_mci_cleanup_slot(struct dw_mci_slot *slot, unsigned int id)
@@ -1937,16 +2064,78 @@ static bool mci_wait_reset(struct device *dev, struct dw_mci *host)
 	return false;
 }
 
+#ifdef CONFIG_OF
+static struct dw_mci_of_quirks {
+	char *quirk;
+	int id;
+} of_quriks[] = {
+	{
+		.quirk	= "supports-highspeed",
+		.id	= DW_MCI_QUIRK_HIGHSPEED,
+	}, {
+		.quirk	= "card-detection-broken",
+		.id	= DW_MCI_QUIRK_BROKEN_CARD_DETECTION,
+	}, {
+		.quirk	= "no-write-protect",
+		.id	= DW_MCI_QUIRK_NO_WRITE_PROTECT,
+	}
+};
+
+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, cnt;
+
+	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 */
+	cnt = sizeof(of_quriks) / sizeof(struct dw_mci_of_quirks);
+	for (idx = 0; idx < cnt; idx++)
+		if (of_get_property(np, of_quriks[idx].quirk, NULL))
+			pdata->quirks |= of_quriks[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) {
-		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) {
diff --git a/drivers/mmc/host/dw_mmc.h b/drivers/mmc/host/dw_mmc.h
index 15c27e1..1ecaa02 100644
--- a/drivers/mmc/host/dw_mmc.h
+++ b/drivers/mmc/host/dw_mmc.h
@@ -182,4 +182,13 @@ extern int dw_mci_suspend(struct dw_mci *host);
 extern int dw_mci_resume(struct dw_mci *host);
 #endif
 
+/* Variations in the dw_mci controller */
+#define DW_MCI_TYPE_SYNOPSIS		0
+
+/* dw_mci platform driver data */
+struct dw_mci_drv_data {
+	unsigned long		ctrl_type;
+	unsigned long		*caps;
+};
+
 #endif /* _DW_MMC_H_ */
diff --git a/include/linux/mmc/dw_mmc.h b/include/linux/mmc/dw_mmc.h
index b72e4aa..ae45e4f 100644
--- a/include/linux/mmc/dw_mmc.h
+++ b/include/linux/mmc/dw_mmc.h
@@ -78,6 +78,7 @@ struct mmc_data;
  * @data_offset: Set the offset of DATA register according to VERID.
  * @dev: Device associated with the MMC controller.
  * @pdata: Platform data associated with the MMC controller.
+ * @drv_data: Driver specific data for identified variant of the controller
  * @biu_clk: Pointer to bus interface unit clock instance.
  * @ciu_clk: Pointer to card interface unit clock instance.
  * @slot: Slots sharing this MMC controller.
@@ -160,6 +161,7 @@ struct dw_mci {
 	u16			data_offset;
 	struct device		*dev;
 	struct dw_mci_board	*pdata;
+	struct dw_mci_drv_data	*drv_data;
 	struct clk		*biu_clk;
 	struct clk		*ciu_clk;
 	struct dw_mci_slot	*slot[MAX_MCI_SLOTS];
-- 
1.6.6.rc2