Merge tag 'imx-drivers-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux into arm/drivers

i.MX drivers update for 5.5:
 - Skip return check for those SCU firmware APIs that are defined as
   void function in firmware.
 - Use established serial_number attribute instead of custom one to show
   SoC's unique ID for i.MX8 SoC drivers.
 - Read i.MX8MQ SOC revision from TF-A which parses ROM and exposes the
   value through a SMC call. This improves the situation that SOC
   revision reports 'unknown' on some older revisions.
 - Add a check and warn on unexpected SCU RX to avoid potential stack
   corruption in imx-scu driver.
 - Fix a sparse warning in imx-scu-irq driver by adding missing header.
 - Remove an unneeded call to devm_of_platform_populate() from imx-dsp
   driver.

* tag 'imx-drivers-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux:
  soc: imx8mq: Read SOC revision from TF-A
  soc: imx-scu: Using existing serial_number instead of UID
  soc: imx8: Using existing serial_number instead of UID
  firmware: imx: add missing include of <linux/firmware/imx/sci.h>
  firmware: imx: Remove call to devm_of_platform_populate
  firmware: imx: Skip return value check for some special SCU firmware APIs
  firmware: imx: warn on unexpected RX

Link: https://lore.kernel.org/r/20191105150315.15477-1-shawnguo@kernel.org
Signed-off-by: Olof Johansson <olof@lixom.net>

5 files changed, 79 insertions, 31 deletions

diff --git a/drivers/firmware/imx/imx-dsp.c b/drivers/firmware/imx/imx-dsp.c
index a43d2db5cbdb..4265e9dbed84 100644
--- a/drivers/firmware/imx/imx-dsp.c
+++ b/drivers/firmware/imx/imx-dsp.c
@@ -114,7 +114,7 @@ static int imx_dsp_probe(struct platform_device *pdev)
 
 	dev_info(dev, "NXP i.MX DSP IPC initialized\n");
 
-	return devm_of_platform_populate(dev);
+	return 0;
 out:
 	kfree(chan_name);
 	for (j = 0; j < i; j++) {
diff --git a/drivers/firmware/imx/imx-scu-irq.c b/drivers/firmware/imx/imx-scu-irq.c
index 687121f8c4d5..db655e87cdc8 100644
--- a/drivers/firmware/imx/imx-scu-irq.c
+++ b/drivers/firmware/imx/imx-scu-irq.c
@@ -8,6 +8,7 @@
 
 #include <dt-bindings/firmware/imx/rsrc.h>
 #include <linux/firmware/imx/ipc.h>
+#include <linux/firmware/imx/sci.h>
 #include <linux/mailbox_client.h>
 
 #define IMX_SC_IRQ_FUNC_ENABLE	1
diff --git a/drivers/firmware/imx/imx-scu.c b/drivers/firmware/imx/imx-scu.c
index 04a24a863d6e..03b43b7a6d1d 100644
--- a/drivers/firmware/imx/imx-scu.c
+++ b/drivers/firmware/imx/imx-scu.c
@@ -107,6 +107,12 @@ static void imx_scu_rx_callback(struct mbox_client *c, void *msg)
 	struct imx_sc_rpc_msg *hdr;
 	u32 *data = msg;
 
+	if (!sc_ipc->msg) {
+		dev_warn(sc_ipc->dev, "unexpected rx idx %d 0x%08x, ignore!\n",
+				sc_chan->idx, *data);
+		return;
+	}
+
 	if (sc_chan->idx == 0) {
 		hdr = msg;
 		sc_ipc->rx_size = hdr->size;
@@ -156,6 +162,7 @@ static int imx_scu_ipc_write(struct imx_sc_ipc *sc_ipc, void *msg)
  */
 int imx_scu_call_rpc(struct imx_sc_ipc *sc_ipc, void *msg, bool have_resp)
 {
+	uint8_t saved_svc, saved_func;
 	struct imx_sc_rpc_msg *hdr;
 	int ret;
 
@@ -165,7 +172,11 @@ int imx_scu_call_rpc(struct imx_sc_ipc *sc_ipc, void *msg, bool have_resp)
 	mutex_lock(&sc_ipc->lock);
 	reinit_completion(&sc_ipc->done);
 
-	sc_ipc->msg = msg;
+	if (have_resp) {
+		sc_ipc->msg = msg;
+		saved_svc = ((struct imx_sc_rpc_msg *)msg)->svc;
+		saved_func = ((struct imx_sc_rpc_msg *)msg)->func;
+	}
 	sc_ipc->count = 0;
 	ret = imx_scu_ipc_write(sc_ipc, msg);
 	if (ret < 0) {
@@ -184,9 +195,20 @@ int imx_scu_call_rpc(struct imx_sc_ipc *sc_ipc, void *msg, bool have_resp)
 		/* response status is stored in hdr->func field */
 		hdr = msg;
 		ret = hdr->func;
+		/*
+		 * Some special SCU firmware APIs do NOT have return value
+		 * in hdr->func, but they do have response data, those special
+		 * APIs are defined as void function in SCU firmware, so they
+		 * should be treated as return success always.
+		 */
+		if ((saved_svc == IMX_SC_RPC_SVC_MISC) &&
+			(saved_func == IMX_SC_MISC_FUNC_UNIQUE_ID ||
+			 saved_func == IMX_SC_MISC_FUNC_GET_BUTTON_STATUS))
+			ret = 0;
 	}
 
 out:
+	sc_ipc->msg = NULL;
 	mutex_unlock(&sc_ipc->lock);
 
 	dev_dbg(sc_ipc->dev, "RPC SVC done\n");
diff --git a/drivers/soc/imx/soc-imx-scu.c b/drivers/soc/imx/soc-imx-scu.c
index 50831ebf126a..f2eace5b50fe 100644
--- a/drivers/soc/imx/soc-imx-scu.c
+++ b/drivers/soc/imx/soc-imx-scu.c
@@ -33,12 +33,10 @@ struct imx_sc_msg_misc_get_soc_uid {
 	u32 uid_high;
 } __packed;
 
-static ssize_t soc_uid_show(struct device *dev,
-			    struct device_attribute *attr, char *buf)
+static int imx_scu_soc_uid(u64 *soc_uid)
 {
 	struct imx_sc_msg_misc_get_soc_uid msg;
 	struct imx_sc_rpc_msg *hdr = &msg.hdr;
-	u64 soc_uid;
 	int ret;
 
 	hdr->ver = IMX_SC_RPC_VERSION;
@@ -52,15 +50,13 @@ static ssize_t soc_uid_show(struct device *dev,
 		return ret;
 	}
 
-	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 sprintf(buf, "%016llX\n", soc_uid);
+	return 0;
 }
 
-static DEVICE_ATTR_RO(soc_uid);
-
 static int imx_scu_soc_id(void)
 {
 	struct imx_sc_msg_misc_get_soc_id msg;
@@ -89,6 +85,7 @@ 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);
@@ -112,6 +109,10 @@ 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;
 	soc_dev_attr->soc_id = kasprintf(GFP_KERNEL, "0x%x", val);
@@ -130,19 +131,22 @@ 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_revision;
+		goto free_serial_number;
 	}
 
-	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:
diff --git a/drivers/soc/imx/soc-imx8.c b/drivers/soc/imx/soc-imx8.c
index b9831576dd25..d84ed736cdb0 100644
--- a/drivers/soc/imx/soc-imx8.c
+++ b/drivers/soc/imx/soc-imx8.c
@@ -9,6 +9,7 @@
 #include <linux/slab.h>
 #include <linux/sys_soc.h>
 #include <linux/platform_device.h>
+#include <linux/arm-smccc.h>
 #include <linux/of.h>
 
 #define REV_B1				0x21
@@ -16,6 +17,8 @@
 #define IMX8MQ_SW_INFO_B1		0x40
 #define IMX8MQ_SW_MAGIC_B1		0xff0055aa
 
+#define IMX_SIP_GET_SOC_INFO		0xc2000006
+
 #define OCOTP_UID_LOW			0x410
 #define OCOTP_UID_HIGH			0x420
 
@@ -29,13 +32,21 @@ struct imx8_soc_data {
 
 static u64 soc_uid;
 
-static ssize_t soc_uid_show(struct device *dev,
-			    struct device_attribute *attr, char *buf)
+#ifdef CONFIG_HAVE_ARM_SMCCC
+static u32 imx8mq_soc_revision_from_atf(void)
 {
-	return sprintf(buf, "%016llX\n", soc_uid);
-}
+	struct arm_smccc_res res;
 
-static DEVICE_ATTR_RO(soc_uid);
+	arm_smccc_smc(IMX_SIP_GET_SOC_INFO, 0, 0, 0, 0, 0, 0, 0, &res);
+
+	if (res.a0 == SMCCC_RET_NOT_SUPPORTED)
+		return 0;
+	else
+		return res.a0 & 0xff;
+}
+#else
+static inline u32 imx8mq_soc_revision_from_atf(void) { return 0; };
+#endif
 
 static u32 __init imx8mq_soc_revision(void)
 {
@@ -51,9 +62,16 @@ static u32 __init imx8mq_soc_revision(void)
 	ocotp_base = of_iomap(np, 0);
 	WARN_ON(!ocotp_base);
 
-	magic = readl_relaxed(ocotp_base + IMX8MQ_SW_INFO_B1);
-	if (magic == IMX8MQ_SW_MAGIC_B1)
-		rev = REV_B1;
+	/*
+	 * SOC revision on older imx8mq is not available in fuses so query
+	 * the value from ATF instead.
+	 */
+	rev = imx8mq_soc_revision_from_atf();
+	if (!rev) {
+		magic = readl_relaxed(ocotp_base + IMX8MQ_SW_INFO_B1);
+		if (magic == IMX8MQ_SW_MAGIC_B1)
+			rev = REV_B1;
+	}
 
 	soc_uid = readl_relaxed(ocotp_base + OCOTP_UID_HIGH);
 	soc_uid <<= 32;
@@ -174,22 +192,25 @@ static int __init imx8_soc_init(void)
 		goto free_soc;
 	}
 
+	soc_dev_attr->serial_number = kasprintf(GFP_KERNEL, "%016llX", soc_uid);
+	if (!soc_dev_attr->serial_number) {
+		ret = -ENOMEM;
+		goto free_rev;
+	}
+
 	soc_dev = soc_device_register(soc_dev_attr);
 	if (IS_ERR(soc_dev)) {
 		ret = PTR_ERR(soc_dev);
-		goto free_rev;
+		goto free_serial_number;
 	}
 
-	ret = device_create_file(soc_device_to_device(soc_dev),
-				 &dev_attr_soc_uid);
-	if (ret)
-		goto free_rev;
-
 	if (IS_ENABLED(CONFIG_ARM_IMX_CPUFREQ_DT))
 		platform_device_register_simple("imx-cpufreq-dt", -1, NULL, 0);
 
 	return 0;
 
+free_serial_number:
+	kfree(soc_dev_attr->serial_number);
 free_rev:
 	if (strcmp(soc_dev_attr->revision, "unknown"))
 		kfree(soc_dev_attr->revision);