From 22eb90db936755e5d600a4561a0cc7a82c791eb9 Mon Sep 17 00:00:00 2001
From: Christophe RICARD <christophe.ricard@gmail.com>
Date: Sat, 13 Feb 2016 16:15:32 +0100
Subject: [PATCH] tpm/st33zp24: Add support for acpi probing for i2c device.

Add support for acpi probing. SMO3324 is used for st33zp24.
It has been tested with the following acpi node on Minnowboard:

Device (TPM1)
{
	Name (_ADR, Zero)  // _ADR: Address
	Name (_HID, "SMO3324")  // _HID: Hardware ID
	Name (_CID, "SMO3324")  // _CID: Compatible ID
	Name (_DDN, "SMO TPM")  // _DDN: DOS Device Name
	Name (_UID, One)  // _UID: Unique ID
	Method (_CRS, 0, NotSerialized)  // _CRS: Current Resource Settings
	{
		Name (SBUF, ResourceTemplate ()
		{
			I2cSerialBus (0x0013, 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.TPM1._CRS.SBUF */
	}

	Method (_STA, 0, NotSerialized)  // _STA: Status
	{
		Return (0x0F)
	}
}

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
---
 drivers/char/tpm/st33zp24/i2c.c | 50 +++++++++++++++++++++++++++++++++
 1 file changed, 50 insertions(+)

diff --git a/drivers/char/tpm/st33zp24/i2c.c b/drivers/char/tpm/st33zp24/i2c.c
index a49b6f10836d..b20cc2ba98cc 100644
--- a/drivers/char/tpm/st33zp24/i2c.c
+++ b/drivers/char/tpm/st33zp24/i2c.c
@@ -19,8 +19,10 @@
 #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/tpm.h>
 #include <linux/platform_data/st33zp24.h>
 
@@ -108,6 +110,43 @@ static const struct st33zp24_phy_ops i2c_phy_ops = {
 	.recv = st33zp24_i2c_recv,
 };
 
+static int st33zp24_i2c_acpi_request_resources(struct st33zp24_i2c_phy *phy)
+{
+	struct i2c_client *client = phy->client;
+	const struct acpi_device_id *id;
+	struct gpio_desc *gpiod_lpcpd;
+	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 LPCPD GPIO from ACPI */
+	gpiod_lpcpd = devm_gpiod_get_index(dev, "TPM IO LPCPD", 1,
+					   GPIOD_OUT_HIGH);
+	if (IS_ERR(gpiod_lpcpd)) {
+		dev_err(&client->dev,
+			"Failed to retrieve lpcpd-gpios from acpi.\n");
+		phy->io_lpcpd = -1;
+		/*
+		 * lpcpd pin is not specified. This is not an issue as
+		 * power management can be also managed by TPM specific
+		 * commands. So leave with a success status code.
+		 */
+		return 0;
+	}
+
+	phy->io_lpcpd = desc_to_gpio(gpiod_lpcpd);
+
+	return 0;
+}
+
 static int st33zp24_i2c_of_request_resources(struct st33zp24_i2c_phy *phy)
 {
 	struct device_node *pp;
@@ -214,6 +253,10 @@ static int st33zp24_i2c_probe(struct i2c_client *client,
 		ret = st33zp24_i2c_request_resources(client, phy);
 		if (ret)
 			return ret;
+	} else if (ACPI_HANDLE(&client->dev)) {
+		ret = st33zp24_i2c_acpi_request_resources(phy);
+		if (ret)
+			return ret;
 	}
 
 	return st33zp24_probe(phy, &i2c_phy_ops, &client->dev, client->irq,
@@ -244,6 +287,12 @@ static const struct of_device_id of_st33zp24_i2c_match[] = {
 };
 MODULE_DEVICE_TABLE(of, of_st33zp24_i2c_match);
 
+static const struct acpi_device_id st33zp24_i2c_acpi_match[] = {
+	{"SMO3324"},
+	{}
+};
+MODULE_DEVICE_TABLE(acpi, st33zp24_i2c_acpi_match);
+
 static SIMPLE_DEV_PM_OPS(st33zp24_i2c_ops, st33zp24_pm_suspend,
 			 st33zp24_pm_resume);
 
@@ -252,6 +301,7 @@ static struct i2c_driver st33zp24_i2c_driver = {
 		.name = TPM_ST33_I2C,
 		.pm = &st33zp24_i2c_ops,
 		.of_match_table = of_match_ptr(of_st33zp24_i2c_match),
+		.acpi_match_table = ACPI_PTR(st33zp24_i2c_acpi_match),
 	},
 	.probe = st33zp24_i2c_probe,
 	.remove = st33zp24_i2c_remove,
-- 
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