nfc: st21nfca: Add support for acpi probing for i2c device.

Add support for acpi probing.
SMO2100 is used for st21nfca

It has been tested with the following acpi node on Minnowboard Max:
Note: Remove uicc-present or ese-present Package if one them is not
supported.

Device (NFC1)
{
	Name (_ADR, Zero)  // _ADR: Address
	Name (_HID, "SMO2100")  // _HID: Hardware ID
	Name (_CID, "SMO2100")  // _CID: Compatible ID
	Name (_DDN, "SMO NFC")  // _DDN: DOS Device Name
	Name (_UID, One)  // _UID: Unique ID
	Name (_DSD, Package (0x02)
	{
		/* Device Properties for _DSD */
		ToUUID ("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
		Package (0x02)
		{
			Package (0x02) { "uicc-present", 1 },
			Package (0x02) { "ese-present", 1 }
		}
	})
	Method (_CRS, 0, NotSerialized)  // _CRS: Current Resource Settings
	{
		Name (SBUF, ResourceTemplate ()
		{
			I2cSerialBus (0x0001, ControllerInitiated, 400000,
				      AddressingMode7Bit, "\\_SB.I2C7",
				      0x00, ResourceConsumer, ,)
			GpioInt (Edge, ActiveHigh, ExclusiveAndWake, PullNone, 0x0000,
				 "\\_SB.GPO2", 0x00, ResourceConsumer, ,)
			{       // Pin list
				0x0001
			}
			GpioIo (Exclusive, PullDefault, 0x0000, 0x0000, IoRestrictionOutputOnly,
				"\\_SB.GPO2", 0x00, ResourceConsumer, ,)
			{       // Pin list
				0x0002,
			}
		})
		Return (SBUF) /* \_SB_.I2C7.NFC1._CRS.SBUF */
	}
	Method (_STA, 0, NotSerialized)  // _STA: Status
	{
		Return (0x0F)
	}
}
Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/nfc/st21nfca/i2c.c

@@ -21,8 +21,10 @@
 #include <linux/module.h>
 #include <linux/i2c.h>
 #include <linux/gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/of_irq.h>
 #include <linux/of_gpio.h>
+#include <linux/acpi.h>
 #include <linux/miscdevice.h>
 #include <linux/interrupt.h>
 #include <linux/delay.h>
@@ -205,7 +207,6 @@ static int st21nfca_hci_i2c_write(void *phy_id, struct sk_buff *skb)
 
 	I2C_DUMP_SKB("st21nfca_hci_i2c_write", skb);
 
-
 	if (phy->hard_fault != 0)
 		return phy->hard_fault;
 
@@ -504,6 +505,41 @@ static struct nfc_phy_ops i2c_phy_ops = {
 	.disable = st21nfca_hci_i2c_disable,
 };
 
+static int st21nfca_hci_i2c_acpi_request_resources(struct i2c_client *client)
+{
+	struct st21nfca_i2c_phy *phy = i2c_get_clientdata(client);
+	const struct acpi_device_id *id;
+	struct gpio_desc *gpiod_ena;
+	struct device *dev;
+
+	if (!client)
+		return -EINVAL;
+
+	dev = &client->dev;
+
+	/* Match the struct device against a given list of ACPI IDs */
+	id = acpi_match_device(dev->driver->acpi_match_table, dev);
+	if (!id)
+		return -ENODEV;
+
+	/* Get EN GPIO from ACPI */
+	gpiod_ena = devm_gpiod_get_index(dev, ST21NFCA_GPIO_NAME_EN, 1,
+					 GPIOD_OUT_LOW);
+	if (!IS_ERR(gpiod_ena))
+		phy->gpio_ena = desc_to_gpio(gpiod_ena);
+
+	phy->gpio_ena = desc_to_gpio(gpiod_ena);
+
+	phy->irq_polarity = irq_get_trigger_type(client->irq);
+
+	phy->se_status.is_ese_present =
+				device_property_present(dev, "ese-present");
+	phy->se_status.is_uicc_present =
+				device_property_present(dev, "uicc-present");
+
+	return 0;
+}
+
 static int st21nfca_hci_i2c_of_request_resources(struct i2c_client *client)
 {
 	struct st21nfca_i2c_phy *phy = i2c_get_clientdata(client);
@@ -617,6 +653,12 @@ static int st21nfca_hci_i2c_probe(struct i2c_client *client,
 			nfc_err(&client->dev, "Cannot get platform resources\n");
 			return r;
 		}
+	} else if (ACPI_HANDLE(&client->dev)) {
+		r = st21nfca_hci_i2c_acpi_request_resources(client);
+		if (r) {
+			nfc_err(&client->dev, "Cannot get ACPI data\n");
+			return r;
+		}
 	} else {
 		nfc_err(&client->dev, "st21nfca platform resources not available\n");
 		return -ENODEV;
@@ -665,6 +707,12 @@ static struct i2c_device_id st21nfca_hci_i2c_id_table[] = {
 };
 MODULE_DEVICE_TABLE(i2c, st21nfca_hci_i2c_id_table);
 
+static const struct acpi_device_id st21nfca_hci_i2c_acpi_match[] = {
+	{"SMO2100", 0},
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, st21nfca_hci_i2c_acpi_match);
+
 static const struct of_device_id of_st21nfca_i2c_match[] = {
 	{ .compatible = "st,st21nfca-i2c", },
 	{ .compatible = "st,st21nfca_i2c", },
@@ -677,6 +725,7 @@ static struct i2c_driver st21nfca_hci_i2c_driver = {
 		.owner = THIS_MODULE,
 		.name = ST21NFCA_HCI_I2C_DRIVER_NAME,
 		.of_match_table = of_match_ptr(of_st21nfca_i2c_match),
+		.acpi_match_table = ACPI_PTR(st21nfca_hci_i2c_acpi_match),
 	},
 	.probe = st21nfca_hci_i2c_probe,
 	.id_table = st21nfca_hci_i2c_id_table,