Revert "soc: imx-scu: Using existing serial_number instead of UID"

This reverts commit 974b100d789c22ed42e934ed25e6860fb9fa294b.

The commit [974b100d789c] causes to fail imx_scu_soc_probe() that
leads to the kernel panic in caam_probe() [1].
Revert the commit to fix booting a kernel.

[1] Panic log:
============================
[    0.606411] Internal error: synchronous external abort: 96000010 [#1] PREEMPT SMP
[    0.613921] Modules linked in:
[    0.616988] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.4.91-5.2.0-devel+git.fccb547e325a #1
[    0.625432] Hardware name: Toradex Apalis iMX8QM V1.1 on Apalis Evaluation Board (DT)
[    0.633270] pstate: 40000005 (nZcv daif -PAN -UAO)
[    0.638081] pc : caam_probe+0xab4/0xf10
[    0.641917] lr : caam_probe+0x14c/0xf10
[    0.645754] sp : ffff80001004bb00
[    0.649072] x29: ffff80001004bb00 x28: ffff800011314638
[    0.654390] x27: 0000000000000000 x26: ffff8000112217a8
[    0.659707] x25: ffff00087857a000 x24: ffff800013630f00
[    0.665024] x23: ffff00087857a010 x22: ffff800011891000
[    0.670341] x21: ffff800013600000 x20: 0000000001934211
[    0.675657] x19: ffff000879362880 x18: ffff80001134e428
[    0.680974] x17: ffff000878036a00 x16: ffff0008780365c8
[    0.686291] x15: 0000000031400000 x14: ffffffffff000000
[    0.691607] x13: ffff80001213f000 x12: 0000000000000001
[    0.696924] x11: 0000000000000004 x10: 0101010101010101
[    0.702241] x9 : ffffffffffffffff x8 : 0000000000000008
[    0.707563] x7 : 0000000000000007 x6 : 0000000000000004
[    0.712884] x5 : 0000000000000001 x4 : ffff00087f7dc720
[    0.718201] x3 : 0000000000000004 x2 : 0000000000000000
[    0.723517] x1 : 0000000000000001 x0 : ffff800013600004
[    0.728837] Call trace:
[    0.731290]  caam_probe+0xab4/0xf10
[    0.734783]  platform_drv_probe+0x50/0xa0
[    0.738796]  really_probe+0xd4/0x318
[    0.742374]  driver_probe_device+0x54/0xe8
[    0.746471]  device_driver_attach+0x6c/0x78
[    0.750659]  __driver_attach+0x54/0xd0
[    0.754411]  bus_for_each_dev+0x6c/0xc0
[    0.758254]  driver_attach+0x20/0x28
[    0.761830]  bus_add_driver+0x140/0x1e8
[    0.765671]  driver_register+0x60/0x110
[    0.769510]  __platform_driver_register+0x44/0x50
[    0.774229]  caam_driver_init+0x18/0x20
[    0.778072]  do_one_initcall+0x50/0x1a8
[    0.781915]  kernel_init_freeable+0x194/0x23c
[    0.786283]  kernel_init+0x10/0x100
[    0.789781]  ret_from_fork+0x10/0x1c
[    0.793367] Code: d50332bf 52800020 b90002a0 17ffff70 (b9400000)
[    0.799487] ---[ end trace 70e76f5d0eb3a960 ]---
[    0.804175] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
[    0.811843] SMP: stopping secondary CPUs
[    0.815776] Kernel Offset: disabled
[    0.819267] CPU features: 0x0002,2100600c
[    0.823277] Memory Limit: none
[    0.826340] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]---

Related-to: ELB-3326
Signed-off-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>

1 files changed, 18 insertions, 21 deletions

diff --git a/drivers/soc/imx/soc-imx-scu.c b/drivers/soc/imx/soc-imx-scu.c
index a34bd2b469ea..720b15972c21 100644
--- a/drivers/soc/imx/soc-imx-scu.c
+++ b/drivers/soc/imx/soc-imx-scu.c
@@ -35,26 +35,31 @@ struct imx_sc_msg_misc_get_soc_uid {
 	u32 uid_high;
 } __packed;
 
-static int imx_scu_soc_uid(u64 *soc_uid)
+static ssize_t soc_uid_show(struct device *dev,
+			    struct device_attribute *attr, char *buf)
 {
 	struct imx_sc_msg_misc_get_soc_uid msg;
 	struct imx_sc_rpc_msg *hdr = &msg.hdr;
-	int ret;
+	u64 soc_uid;
+
+	memset(&msg, 0, sizeof(msg));
 
 	hdr->ver = IMX_SC_RPC_VERSION;
 	hdr->svc = IMX_SC_RPC_SVC_MISC;
 	hdr->func = IMX_SC_MISC_FUNC_UNIQUE_ID;
 	hdr->size = 1;
 
-	ret = imx_scu_call_rpc(soc_ipc_handle, &msg, true);
+	imx_scu_call_rpc(soc_ipc_handle, &msg, true);
 
-	*soc_uid = msg.uid_high;
-	*soc_uid <<= 32;
-	*soc_uid |= msg.uid_low;
+	soc_uid = msg.uid_high;
+	soc_uid <<= 32;
+	soc_uid |= msg.uid_low;
 
-	return ret;
+	return sprintf(buf, "%016llX\n", soc_uid);
 }
 
+static DEVICE_ATTR_RO(soc_uid);
+
 static int imx_scu_soc_id(void)
 {
 	struct imx_sc_msg_misc_get_soc_id msg;
@@ -83,7 +88,6 @@ static int imx_scu_soc_probe(struct platform_device *pdev)
 	struct soc_device_attribute *soc_dev_attr;
 	struct soc_device *soc_dev;
 	int id, ret;
-	u64 uid = 0;
 	u32 val;
 
 	ret = imx_scu_get_handle(&soc_ipc_handle);
@@ -107,10 +111,6 @@ static int imx_scu_soc_probe(struct platform_device *pdev)
 	if (id < 0)
 		return -EINVAL;
 
-	ret = imx_scu_soc_uid(&uid);
-	if (ret < 0)
-		return -EINVAL;
-
 	/* format soc_id value passed from SCU firmware */
 	val = id & 0x1f;
 	if (of_machine_is_compatible("fsl,imx8qm")) {
@@ -133,22 +133,19 @@ static int imx_scu_soc_probe(struct platform_device *pdev)
 		goto free_soc_id;
 	}
 
-	soc_dev_attr->serial_number = kasprintf(GFP_KERNEL, "%016llX", uid);
-	if (!soc_dev_attr->serial_number) {
-		ret = -ENOMEM;
-		goto free_revision;
-	}
-
 	soc_dev = soc_device_register(soc_dev_attr);
 	if (IS_ERR(soc_dev)) {
 		ret = PTR_ERR(soc_dev);
-		goto free_serial_number;
+		goto free_revision;
 	}
 
+	ret = device_create_file(soc_device_to_device(soc_dev),
+				 &dev_attr_soc_uid);
+	if (ret)
+		goto free_revision;
+
 	return 0;
 
-free_serial_number:
-	kfree(soc_dev_attr->serial_number);
 free_revision:
 	kfree(soc_dev_attr->revision);
 free_soc_id: