linux-kernel - [PATCH v2 2/3] tpm_tis: Use devm_ioremap

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Date:	Tue,  1 Dec 2015 11:58:28 -0700
From:	Jason Gunthorpe <jgunthorpe@...idianresearch.com>
To:	Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>,
	tpmdd-devel@...ts.sourceforge.net, linux-kernel@...r.kernel.org
Cc:	Martin Wilck <Martin.Wilck@...fujitsu.com>,
	Peter Huewe <peterhuewe@....de>,
	Uwe Kleine-König 
	<u.kleine-koenig@...gutronix.de>
Subject: [PATCH v2 2/3] tpm_tis: Use devm_ioremap_resource

This does a request_resource under the covers which means tis holds a
lock on the memory range it is using so other drivers cannot grab it.
When doing probing it is important to ensure that other drivers are
not using the same range before tis starts touching it.

To do this flow the actual struct resource from the device right
through to devm_ioremap_resource. This ensures all the proper resource
meta-data is carried down.

Signed-off-by: Jason Gunthorpe <jgunthorpe@...idianresearch.com>
---
 drivers/char/tpm/tpm_tis.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index 0a2d94f3d679..1032855c46b2 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -67,14 +67,16 @@ enum tis_defaults {
 };
 
 struct tpm_info {
-	unsigned long start;
-	unsigned long len;
+	struct resource res;
 	int irq;
 };
 
 static struct tpm_info tis_default_info = {
-	.start = TIS_MEM_BASE,
-	.len = TIS_MEM_LEN,
+	.res = {
+		.start = TIS_MEM_BASE,
+		.end = TIS_MEM_BASE + TIS_MEM_LEN - 1,
+		.flags = IORESOURCE_MEM,
+	},
 	.irq = 0,
 };
 
@@ -716,7 +718,7 @@ static int tpm_tis_init(struct device *dev, struct tpm_info *tpm_info,
 	chip->acpi_dev_handle = acpi_dev_handle;
 #endif
 
-	chip->vendor.iobase = devm_ioremap(dev, tpm_info->start, tpm_info->len);
+	chip->vendor.iobase = devm_ioremap_resource(dev, &tpm_info->res);
 	if (!chip->vendor.iobase)
 		return -EIO;
 
@@ -899,9 +901,12 @@ static int tpm_tis_pnp_init(struct pnp_dev *pnp_dev,
 {
 	struct tpm_info tpm_info = {};
 	acpi_handle acpi_dev_handle = NULL;
+	struct resource *res;
 
-	tpm_info.start = pnp_mem_start(pnp_dev, 0);
-	tpm_info.len = pnp_mem_len(pnp_dev, 0);
+	res = pnp_get_resource(pnp_dev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+	memcpy(&tpm_info.res, res, sizeof(*res));
 
 	if (pnp_irq_valid(pnp_dev, 0))
 		tpm_info.irq = pnp_irq(pnp_dev, 0);
@@ -964,12 +969,9 @@ static int tpm_check_resource(struct acpi_resource *ares, void *data)
 	struct tpm_info *tpm_info = (struct tpm_info *) data;
 	struct resource res;
 
-	if (acpi_dev_resource_interrupt(ares, 0, &res)) {
+	if (acpi_dev_resource_interrupt(ares, 0, &res))
 		tpm_info->irq = res.start;
-	} else if (acpi_dev_resource_memory(ares, &res)) {
-		tpm_info->start = res.start;
-		tpm_info->len = resource_size(&res);
-	}
+	acpi_dev_resource_memory(ares, &tpm_info->res);
 
 	return 1;
 }
@@ -992,6 +994,9 @@ static int tpm_tis_acpi_init(struct acpi_device *acpi_dev)
 
 	acpi_dev_free_resource_list(&resources);
 
+	if (resource_size(&tpm_info.res) == 0)
+		return -ENODEV;
+
 	if (is_itpm(acpi_dev))
 		itpm = true;
 
-- 
2.1.4

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