[PATCH 1/3] crypto: ixp4xx: convert to platform driver

[Linus Walleij]

From: Arnd Bergmann <arnd at arndb.de>

The ixp4xx_crypto driver traditionally registers a bare platform
device without attaching it to a driver, and detects the hardware
at module init time by reading an SoC specific hardware register.

Change this to the conventional method of registering the platform
device from the platform code itself when the device is present,
turning the module_init/module_exit functions into probe/release
driver callbacks.

This enables compile-testing as well as potentially having ixp4xx
coexist with other ARMv5 platforms in the same kernel in the future.

Signed-off-by: Arnd Bergmann <arnd at arndb.de>
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
Herbert, David: I am looking for an ACK to take this
into the ARM SoC tree as we want to change more stuff in
the machine at the same time that we want to resolve
there.
---
 arch/arm/mach-ixp4xx/common.c  | 26 ++++++++++++++++++++++++
 drivers/crypto/Kconfig         |  3 ++-
 drivers/crypto/ixp4xx_crypto.c | 37 ++++++++++++----------------------
 3 files changed, 41 insertions(+), 25 deletions(-)

diff --git a/arch/arm/mach-ixp4xx/common.c b/arch/arm/mach-ixp4xx/common.c
index 000f672a94c9..007a44412e24 100644
--- a/arch/arm/mach-ixp4xx/common.c
+++ b/arch/arm/mach-ixp4xx/common.c
@@ -233,12 +233,38 @@ static struct platform_device *ixp46x_devices[] __initdata = {
 unsigned long ixp4xx_exp_bus_size;
 EXPORT_SYMBOL(ixp4xx_exp_bus_size);
 
+static struct platform_device_info ixp_dev_info __initdata = {
+	.name		= "ixp4xx_crypto",
+	.id		= 0,
+	.dma_mask	= DMA_BIT_MASK(32),
+};
+
+static int __init ixp_crypto_register(void)
+{
+	struct platform_device *pdev;
+
+	if (!(~(*IXP4XX_EXP_CFG2) & (IXP4XX_FEATURE_HASH |
+				IXP4XX_FEATURE_AES | IXP4XX_FEATURE_DES))) {
+		printk(KERN_ERR "ixp_crypto: No HW crypto available\n");
+		return -ENODEV;
+	}
+
+	pdev = platform_device_register_full(&ixp_dev_info);
+	if (IS_ERR(pdev))
+		return PTR_ERR(pdev);
+
+	return 0;
+}
+
 void __init ixp4xx_sys_init(void)
 {
 	ixp4xx_exp_bus_size = SZ_16M;
 
 	platform_add_devices(ixp4xx_devices, ARRAY_SIZE(ixp4xx_devices));
 
+	if (IS_ENABLED(CONFIG_CRYPTO_DEV_IXP4XX))
+		ixp_crypto_register();
+
 	if (cpu_is_ixp46x()) {
 		int region;
 
diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
index 9a4c275a1335..aa389e741876 100644
--- a/drivers/crypto/Kconfig
+++ b/drivers/crypto/Kconfig
@@ -324,7 +324,8 @@ config CRYPTO_DEV_TALITOS2
 
 config CRYPTO_DEV_IXP4XX
 	tristate "Driver for IXP4xx crypto hardware acceleration"
-	depends on ARCH_IXP4XX && IXP4XX_QMGR && IXP4XX_NPE
+	depends on IXP4XX_QMGR && IXP4XX_NPE
+	depends on ARCH_IXP4XX || COMPILE_TEST
 	select CRYPTO_LIB_DES
 	select CRYPTO_AEAD
 	select CRYPTO_AUTHENC
diff --git a/drivers/crypto/ixp4xx_crypto.c b/drivers/crypto/ixp4xx_crypto.c
index 0616e369522e..879b93927e2a 100644
--- a/drivers/crypto/ixp4xx_crypto.c
+++ b/drivers/crypto/ixp4xx_crypto.c
@@ -224,8 +224,6 @@ static dma_addr_t crypt_phys;
 
 static int support_aes = 1;
 
-#define DRIVER_NAME "ixp4xx_crypto"
-
 static struct platform_device *pdev;
 
 static inline dma_addr_t crypt_virt2phys(struct crypt_ctl *virt)
@@ -432,11 +430,6 @@ static int init_ixp_crypto(struct device *dev)
 	int ret = -ENODEV;
 	u32 msg[2] = { 0, 0 };
 
-	if (! ( ~(*IXP4XX_EXP_CFG2) & (IXP4XX_FEATURE_HASH |
-				IXP4XX_FEATURE_AES | IXP4XX_FEATURE_DES))) {
-		printk(KERN_ERR "ixp_crypto: No HW crypto available\n");
-		return ret;
-	}
 	npe_c = npe_request(NPE_ID);
 	if (!npe_c)
 		return ret;
@@ -1364,26 +1357,17 @@ static struct ixp_aead_alg ixp4xx_aeads[] = {
 
 #define IXP_POSTFIX "-ixp4xx"
 
-static const struct platform_device_info ixp_dev_info __initdata = {
-	.name		= DRIVER_NAME,
-	.id		= 0,
-	.dma_mask	= DMA_BIT_MASK(32),
-};
-
-static int __init ixp_module_init(void)
+static int ixp_crypto_probe(struct platform_device *_pdev)
 {
 	int num = ARRAY_SIZE(ixp4xx_algos);
 	int i, err;
 
-	pdev = platform_device_register_full(&ixp_dev_info);
-	if (IS_ERR(pdev))
-		return PTR_ERR(pdev);
+	pdev = _pdev;
 
 	err = init_ixp_crypto(&pdev->dev);
-	if (err) {
-		platform_device_unregister(pdev);
+	if (err)
 		return err;
-	}
+
 	for (i=0; i< num; i++) {
 		struct skcipher_alg *cra = &ixp4xx_algos[i].crypto;
 
@@ -1456,7 +1440,7 @@ static int __init ixp_module_init(void)
 	return 0;
 }
 
-static void __exit ixp_module_exit(void)
+static int ixp_crypto_remove(struct platform_device *pdev)
 {
 	int num = ARRAY_SIZE(ixp4xx_algos);
 	int i;
@@ -1471,11 +1455,16 @@ static void __exit ixp_module_exit(void)
 			crypto_unregister_skcipher(&ixp4xx_algos[i].crypto);
 	}
 	release_ixp_crypto(&pdev->dev);
-	platform_device_unregister(pdev);
+
+	return 0;
 }
 
-module_init(ixp_module_init);
-module_exit(ixp_module_exit);
+static struct platform_driver ixp_crypto_driver = {
+	.probe = ixp_crypto_probe,
+	.remove = ixp_crypto_remove,
+	.driver = { .name = "ixp4xx_crypto" },
+};
+module_platform_driver(ixp_crypto_driver);
 
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Christian Hohnstaedt <chohnstaedt at innominate.com>");
-- 
2.30.2