[PATCH 5/9] mmc: dw_mmc: add device tree support

Thomas Abraham
2012-07-17T10:37:51Z

Add device tree based discovery support.

Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
---
.../devicetree/bindings/mmc/synposis-dw-mshc.txt | 99 ++++++++++
drivers/mmc/host/dw_mmc-pltfm.c | 23 +++
drivers/mmc/host/dw_mmc.c | 201 +++++++++++++++++++-
drivers/mmc/host/dw_mmc.h | 9 +
include/linux/mmc/dw_mmc.h | 2 +
5 files changed, 328 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..e69a295
--- /dev/null
+++ b/Documentation/devicetree/bindings/mmc/synposis-dw-mshc.txt
@@ -0,0 +1,99 @@
+* 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 properties described by mmc.txt and the
+properties used by the dw_mmc driver.
+
+Required Properties:
+
+* compatible: should be one of the following
+ - 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: Refer to mmc.txt for details.
+
+ * cd-gpios: Refer to mmc.txt for details.
+
+ * wp-gpios: Refer to mmc.txt for details.
+
+ * 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..a048c1a 100644
--- a/drivers/mmc/host/dw_mmc-pltfm.c
+++ b/drivers/mmc/host/dw_mmc-pltfm.c
@@ -19,8 +19,22 @@
#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);
+#endif
+
static int dw_mci_pltfm_probe(struct platform_device *pdev)
{
struct dw_mci *host;
@@ -51,6 +65,14 @@ 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(of_match_ptr(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 +133,7 @@ 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 cb96a40..7af4089 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_quirks[] = {
+ {
+ .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_quirks) / sizeof(struct dw_mci_of_quirks);
+ for (idx = 0; idx < cnt; 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) {
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