[PATCH v2 0/2] firmware: arm_scmi: create scmi devices for protocols that not have of_node

[PATCH v2 0/2] firmware: arm_scmi: create scmi devices for protocols that not have of_node

[Peng Fan (OSS)]

Per
https://lore.kernel.org/all/20230125141113.kkbowopusikuogx6@bogus/
"
In short we shouldn't have to add a node if there are no consumers. It
was one of the topic of discussion initially when SCMI binding was added
and they exist only for the consumers otherwise we don't need it as
everything is discoverable from the interface.
"
https://lore.kernel.org/all/Y9JLUIioxFPn4BS0@e120937-lin/
If a node has its own channel, the of_node is still needed.

i.MX95 SCMI firmware not have dedicated channel for 0x12, and no need
of_node. This patchset is to support protocol 0x12 without the procotol
node in device tree.

Without of_node, still need to create the scmi devices. As of now,
it is based on an array 'protocols[]' in 'scmi_probe'. 

And no of_node, means no per protocol channel, so reuse the base
protocol channel. Need patch chan_available to support.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
Changes in v2:
- Fix a build error that missing ";" 
- Print hex value of protocol id when error
- Link to v1: https://lore.kernel.org/r/20240626-scmi-driver-v1-0-f16d777e004a@nxp.com

---
Peng Fan (2):
      firmware: arm_scmi: channel unavailable if no of_node
      firmware: arm_scmi: create scmi_devices that not have of_node

 drivers/firmware/arm_scmi/driver.c  | 33 ++++++++++++++++++++++++++++++++-
 drivers/firmware/arm_scmi/mailbox.c |  2 ++
 drivers/firmware/arm_scmi/optee.c   |  3 +++
 drivers/firmware/arm_scmi/smc.c     |  7 ++++++-
 drivers/firmware/arm_scmi/virtio.c  |  3 +++
 5 files changed, 46 insertions(+), 2 deletions(-)
---
base-commit: d8003eb2eb0200352b5d63af77ec0912a52e79ad
change-id: 20240626-scmi-driver-96dc61b036a2

Best regards,
-- 
Peng Fan <peng.fan@nxp.com>

[PATCH v2 1/2] firmware: arm_scmi: channel unavailable if no of_node

[Peng Fan (OSS)]

From: Peng Fan <peng.fan@nxp.com>

If there is no of_node for the protocol, there is no per protocol
channel, so return false. Then it will reuse the base protocol
channel per `scmi_chan_setup`.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/firmware/arm_scmi/mailbox.c | 2 ++
 drivers/firmware/arm_scmi/optee.c   | 3 +++
 drivers/firmware/arm_scmi/smc.c     | 7 ++++++-
 drivers/firmware/arm_scmi/virtio.c  | 3 +++
 4 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/arm_scmi/mailbox.c b/drivers/firmware/arm_scmi/mailbox.c
index 0219a12e3209..4f3abc933315 100644
--- a/drivers/firmware/arm_scmi/mailbox.c
+++ b/drivers/firmware/arm_scmi/mailbox.c
@@ -71,6 +71,8 @@ static bool mailbox_chan_available(struct device_node *of_node, int idx)
 {
 	int num_mb;
 
+	if (!of_node)
+		return false;
 	/*
 	 * Just check if bidirrectional channels are involved, and check the
 	 * index accordingly; proper full validation will be made later
diff --git a/drivers/firmware/arm_scmi/optee.c b/drivers/firmware/arm_scmi/optee.c
index 4e7944b91e38..c0a198baa706 100644
--- a/drivers/firmware/arm_scmi/optee.c
+++ b/drivers/firmware/arm_scmi/optee.c
@@ -334,6 +334,9 @@ static bool scmi_optee_chan_available(struct device_node *of_node, int idx)
 {
 	u32 channel_id;
 
+	if (!of_node)
+		return false;
+
 	return !of_property_read_u32_index(of_node, "linaro,optee-channel-id",
 					   idx, &channel_id);
 }
diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c
index 39936e1dd30e..913e45c205fb 100644
--- a/drivers/firmware/arm_scmi/smc.c
+++ b/drivers/firmware/arm_scmi/smc.c
@@ -81,7 +81,12 @@ static irqreturn_t smc_msg_done_isr(int irq, void *data)
 
 static bool smc_chan_available(struct device_node *of_node, int idx)
 {
-	struct device_node *np = of_parse_phandle(of_node, "shmem", 0);
+	struct device_node *np;
+
+	if (!of_node)
+		return false;
+
+	np = of_parse_phandle(of_node, "shmem", 0);
 	if (!np)
 		return false;
 
diff --git a/drivers/firmware/arm_scmi/virtio.c b/drivers/firmware/arm_scmi/virtio.c
index 4892058445ce..4d8d6ad3ab5b 100644
--- a/drivers/firmware/arm_scmi/virtio.c
+++ b/drivers/firmware/arm_scmi/virtio.c
@@ -389,6 +389,9 @@ static bool virtio_chan_available(struct device_node *of_node, int idx)
 {
 	struct scmi_vio_channel *channels, *vioch = NULL;
 
+	if (!of_node)
+		return false;
+
 	if (WARN_ON_ONCE(!scmi_vdev))
 		return false;
 

-- 
2.37.1

[PATCH v2 2/2] firmware: arm_scmi: create scmi_devices that not have of_node

[Peng Fan (OSS)]

From: Peng Fan <peng.fan@nxp.com>

The scmi protocol device tree node is expected to have consumers or
per node properties expect `reg`. For System power management protocol,
if no per node channel information, no need to add it in device tree,
and it will also trigger dtbs_check error "scmi: 'protocol@12' does not
match any of the regexes: 'pinctrl-[0-9]+'".

To enable system power protocol, need to explictily create the scmi
device and bind with protocol driver.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 drivers/firmware/arm_scmi/driver.c | 33 ++++++++++++++++++++++++++++++++-
 1 file changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index 6b6957f4743f..44a6e64eb78e 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -2952,7 +2952,7 @@ static int scmi_debugfs_raw_mode_setup(struct scmi_info *info)
 
 static int scmi_probe(struct platform_device *pdev)
 {
-	int ret;
+	int i, ret;
 	char *err_str = "probe failure\n";
 	struct scmi_handle *handle;
 	const struct scmi_desc *desc;
@@ -2960,6 +2960,7 @@ static int scmi_probe(struct platform_device *pdev)
 	bool coex = IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX);
 	struct device *dev = &pdev->dev;
 	struct device_node *child, *np = dev->of_node;
+	uint32_t protocols[] = { SCMI_PROTOCOL_SYSTEM, SCMI_PROTOCOL_POWERCAP };
 
 	desc = of_device_get_match_data(dev);
 	if (!desc)
@@ -3114,6 +3115,36 @@ static int scmi_probe(struct platform_device *pdev)
 		scmi_create_protocol_devices(child, info, prot_id, NULL);
 	}
 
+	/* Create devices that not have a device node */
+	for (i = 0; i < ARRAY_SIZE(protocols); i++) {
+		void *p;
+		u32 prot_id = protocols[i];
+
+		p = idr_find(&info->active_protocols, prot_id);
+		if (p)
+			continue;
+
+		if (!scmi_is_protocol_implemented(handle, prot_id)) {
+			dev_info(dev, "SCMI protocol 0x%x not implemented\n",
+				 protocols[i]);
+			continue;
+		}
+
+		ret = scmi_txrx_setup(info, NULL, prot_id);
+		if (ret) {
+			dev_err(dev, "SCMI protocol 0x%x txrx setup fail(%d)\n",
+				prot_id, ret);
+			continue;
+		}
+
+		ret = idr_alloc(&info->active_protocols, NULL,
+				prot_id, prot_id + 1, GFP_KERNEL);
+		if (ret != prot_id)
+			continue;
+
+		scmi_create_protocol_devices(NULL, info, prot_id, NULL);
+	}
+
 	return 0;
 
 notification_exit:

-- 
2.37.1