Commit c91eab4b authored by Thomas Abraham's avatar Thomas Abraham Committed by Chris Ball
Browse files

mmc: dw_mmc: add device tree support 



Add device tree based discovery support.

Signed-off-by: default avatarThomas Abraham <thomas.abraham@linaro.org>
Acked-by: default avatarWill Newton <will.newton@imgtec.com>
Signed-off-by: default avatarChris Ball <cjb@laptop.org>
parent b4967aa5

Documentation/devicetree/bindings/mmc/synposis-dw-mshc.txt

0 → 100644
+79 −0
Original line number Diff line number Diff line 
* 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. This file documents

differences between the core mmc properties described by mmc.txt and the

properties used by the Synopsis Designware Mobile Storage Host Controller.



Required Properties:



* compatible: should be

	- snps,dw-mshc: for controllers compliant with synopsis dw-mshc.

* #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: as documented in mmc core bindings.



	* wp-gpios: specifies the write protect gpio line. The format of the

	  gpio specifier depends on the gpio controller. If the write-protect

	  line is not available, this property is optional.



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)



* broken-cd: as documented in mmc core bindings.



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;

		broken-cd;

		fifo-depth = <0x80>;

		card-detect-delay = <200>;



		slot@0 {

			reg = <0>;

			bus-width = <8>;

		};

	};

drivers/mmc/host/dw_mmc-pltfm.c

+9 −0
Original line number Diff line number Diff line
@@ -19,6 +19,8 @@ 
#include <linux/mmc/host.h>

#include <linux/mmc/mmc.h>

#include <linux/mmc/dw_mmc.h>

#include <linux/of.h>



#include "dw_mmc.h"



static int __devinit dw_mci_pltfm_probe(struct platform_device *pdev)
@@ -94,10 +96,17 @@ static int dw_mci_pltfm_resume(struct device *dev) 


static SIMPLE_DEV_PM_OPS(dw_mci_pltfm_pmops, dw_mci_pltfm_suspend, dw_mci_pltfm_resume);



static const struct of_device_id dw_mci_pltfm_match[] = {

	{ .compatible = "snps,dw-mshc", },

	{},

};

MODULE_DEVICE_TABLE(of, dw_mci_pltfm_match);



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,

	},

};

drivers/mmc/host/dw_mmc.c

+123 −7
Original line number Diff line number Diff line
@@ -33,6 +33,7 @@ 
#include <linux/bitops.h>

#include <linux/regulator/consumer.h>

#include <linux/workqueue.h>

#include <linux/of.h>



#include "dw_mmc.h"
@@ -1769,10 +1770,57 @@ static void dw_mci_work_routine_card(struct work_struct *work) 
	}

}



#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)

		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;

}



#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) {

		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) {