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>

1 files changed, 50 insertions, 0 deletions

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,