Re: [PATCH] tpm: Add force device probe option

[Kylene Jo Hall <kjhall@us.ibm.com>]

Some machine manufacturers are not sticking to the TCG specifications
and including an ACPI DSDT entry for the TPM which allows PNP discovery
of the device.  

Fixed up version removes the force=0 and the lack of error handling for
driver_register.

Signed-off-by: Kylene Hall <kjhall@us.ibm.com>
---
 drivers/char/tpm/tpm_tis.c |   76 ++++++++++++++++++++++++++---------
 1 files changed, 57 insertions(+), 19 deletions(-)

--- linux-2.6.18-rc1/drivers/char/tpm/tpm_tis.c	2006-07-05 23:09:49.000000000 -0500
+++ linux-2.6.18-rc1-tpm/drivers/char/tpm/tpm_tis.c	2006-07-13 14:44:18.822694500 -0500
@@ -431,23 +431,18 @@ static int interrupts = 1;
 module_param(interrupts, bool, 0444);
 MODULE_PARM_DESC(interrupts, "Enable interrupts");
 
-static int __devinit tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
-				      const struct pnp_device_id *pnp_id)
+static int tpm_tis_init(struct device *dev, unsigned long start, unsigned long len)
 {
 	u32 vendor, intfcaps, intmask;
 	int rc, i;
-	unsigned long start, len;
 	struct tpm_chip *chip;
 
-	start = pnp_mem_start(pnp_dev, 0);
-	len = pnp_mem_len(pnp_dev, 0);
-
 	if (!start)
 		start = TIS_MEM_BASE;
 	if (!len)
 		len = TIS_MEM_LEN;
 
-	if (!(chip = tpm_register_hardware(&pnp_dev->dev, &tpm_tis)))
+	if (!(chip = tpm_register_hardware(dev, &tpm_tis)))
 		return -ENODEV;
 
 	chip->vendor.iobase = ioremap(start, len);
@@ -464,7 +459,7 @@ static int __devinit tpm_tis_pnp_init(st
 	chip->vendor.timeout_c = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
 	chip->vendor.timeout_d = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
 
-	dev_info(&pnp_dev->dev,
+	dev_info(dev,
 		 "1.2 TPM (device-id 0x%X, rev-id %d)\n",
 		 vendor >> 16, ioread8(chip->vendor.iobase + TPM_RID(0)));
 
@@ -472,26 +467,26 @@ static int __devinit tpm_tis_pnp_init(st
 	intfcaps =
 	    ioread32(chip->vendor.iobase +
 		     TPM_INTF_CAPS(chip->vendor.locality));
-	dev_dbg(&pnp_dev->dev, "TPM interface capabilities (0x%x):\n",
+	dev_dbg(dev, "TPM interface capabilities (0x%x):\n",
 		intfcaps);
 	if (intfcaps & TPM_INTF_BURST_COUNT_STATIC)
-		dev_dbg(&pnp_dev->dev, "\tBurst Count Static\n");
+		dev_dbg(dev, "\tBurst Count Static\n");
 	if (intfcaps & TPM_INTF_CMD_READY_INT)
-		dev_dbg(&pnp_dev->dev, "\tCommand Ready Int Support\n");
+		dev_dbg(dev, "\tCommand Ready Int Support\n");
 	if (intfcaps & TPM_INTF_INT_EDGE_FALLING)
-		dev_dbg(&pnp_dev->dev, "\tInterrupt Edge Falling\n");
+		dev_dbg(dev, "\tInterrupt Edge Falling\n");
 	if (intfcaps & TPM_INTF_INT_EDGE_RISING)
-		dev_dbg(&pnp_dev->dev, "\tInterrupt Edge Rising\n");
+		dev_dbg(dev, "\tInterrupt Edge Rising\n");
 	if (intfcaps & TPM_INTF_INT_LEVEL_LOW)
-		dev_dbg(&pnp_dev->dev, "\tInterrupt Level Low\n");
+		dev_dbg(dev, "\tInterrupt Level Low\n");
 	if (intfcaps & TPM_INTF_INT_LEVEL_HIGH)
-		dev_dbg(&pnp_dev->dev, "\tInterrupt Level High\n");
+		dev_dbg(dev, "\tInterrupt Level High\n");
 	if (intfcaps & TPM_INTF_LOCALITY_CHANGE_INT)
-		dev_dbg(&pnp_dev->dev, "\tLocality Change Int Support\n");
+		dev_dbg(dev, "\tLocality Change Int Support\n");
 	if (intfcaps & TPM_INTF_STS_VALID_INT)
-		dev_dbg(&pnp_dev->dev, "\tSts Valid Int Support\n");
+		dev_dbg(dev, "\tSts Valid Int Support\n");
 	if (intfcaps & TPM_INTF_DATA_AVAIL_INT)
-		dev_dbg(&pnp_dev->dev, "\tData Avail Int Support\n");
+		dev_dbg(dev, "\tData Avail Int Support\n");
 
 	if (request_locality(chip, 0) != 0) {
 		rc = -ENODEV;
@@ -594,6 +589,16 @@ out_err:
 	return rc;
 }
 
+static int __devinit tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
+				      const struct pnp_device_id *pnp_id)
+{
+	unsigned long start, len;
+	start = pnp_mem_start(pnp_dev, 0);
+	len = pnp_mem_len(pnp_dev, 0);
+
+	return tpm_tis_init(&pnp_dev->dev, start, len);
+}
+
 static int tpm_tis_pnp_suspend(struct pnp_dev *dev, pm_message_t msg)
 {
 	return tpm_pm_suspend(&dev->dev, msg);
@@ -628,8 +633,36 @@ module_param_string(hid, tpm_pnp_tbl[TIS
 		    sizeof(tpm_pnp_tbl[TIS_HID_USR_IDX].id), 0444);
 MODULE_PARM_DESC(hid, "Set additional specific HID for this driver to probe");
 
+static struct device_driver tis_drv = {
+	.name = "tpm_tis",
+	.bus = &platform_bus_type,
+	.owner = THIS_MODULE,
+	.suspend = tpm_pm_suspend,
+	.resume = tpm_pm_resume,
+};
+
+static struct platform_device *pdev;
+
+static int force;
+module_param(force, bool, 0444);
+MODULE_PARM_DESC(force, "Force device probe rather than using ACPI entry");
 static int __init init_tis(void)
 {
+	int rc;
+
+	if (force) {
+		rc = driver_register(&tis_drv);
+		if (rc < 0)
+			return rc;
+		if (IS_ERR(pdev=platform_device_register_simple("tpm_tis", -1, NULL, 0)))
+			return PTR_ERR(pdev);
+		if((rc=tpm_tis_init(&pdev->dev, 0, 0)) != 0) {
+			platform_device_unregister(pdev);
+			driver_unregister(&tis_drv);
+		}
+		return rc;
+	}
+
 	return pnp_register_driver(&tis_pnp_driver);
 }
 
@@ -654,7 +687,12 @@ static void __exit cleanup_tis(void)
 		tpm_remove_hardware(chip->dev);
 	}
 	spin_unlock(&tis_lock);
-	pnp_unregister_driver(&tis_pnp_driver);
+	if (force) {
+		platform_device_unregister(pdev);
+		driver_unregister(&tis_drv);
+	}
+	else 
+		pnp_unregister_driver(&tis_pnp_driver);
 }
 
 module_init(init_tis);