[PATCH v2 1/2] firmware: arm_scmi: imx: Support getting syslog of MISC protocol

[Peng Fan <peng.fan@nxp.com>]

MISC protocol supports getting system log regarding system sleep latency,
wakeup interrupt and etc. Add the API for user to retrieve the information
from SM.

Signed-off-by: Peng Fan <peng.fan@nxp.com>
---
 .../firmware/arm_scmi/vendors/imx/imx-sm-misc.c    | 83 ++++++++++++++++++++++
 include/linux/scmi_imx_protocol.h                  |  2 +
 2 files changed, 85 insertions(+)

diff --git a/drivers/firmware/arm_scmi/vendors/imx/imx-sm-misc.c b/drivers/firmware/arm_scmi/vendors/imx/imx-sm-misc.c
index 700a3f24f4efc153ca4a9ef1a9e50a7ece492a18..eae0b0562f6cf1931be612852ba2651f60820e6d 100644
--- a/drivers/firmware/arm_scmi/vendors/imx/imx-sm-misc.c
+++ b/drivers/firmware/arm_scmi/vendors/imx/imx-sm-misc.c
@@ -28,6 +28,7 @@ enum scmi_imx_misc_protocol_cmd {
 	SCMI_IMX_MISC_DISCOVER_BUILD_INFO = 0x6,
 	SCMI_IMX_MISC_CTRL_NOTIFY = 0x8,
 	SCMI_IMX_MISC_CFG_INFO_GET = 0xC,
+	SCMI_IMX_MISC_SYSLOG_GET = 0xD,
 	SCMI_IMX_MISC_BOARD_INFO = 0xE,
 };
 
@@ -89,6 +90,19 @@ struct scmi_imx_misc_cfg_info_out {
 	u8 cfgname[MISC_MAX_CFGNAME];
 };
 
+struct scmi_imx_misc_syslog_in {
+	__le32 flags;
+	__le32 index;
+};
+
+#define REMAINING(x)	le32_get_bits((x), GENMASK(31, 20))
+#define RETURNED(x)	le32_get_bits((x), GENMASK(11, 0))
+
+struct scmi_imx_misc_syslog_out {
+	__le32 numlogflags;
+	__le32 syslog[];
+};
+
 static int scmi_imx_misc_attributes_get(const struct scmi_protocol_handle *ph,
 					struct scmi_imx_misc_info *mi)
 {
@@ -371,10 +385,79 @@ static int scmi_imx_misc_cfg_info_get(const struct scmi_protocol_handle *ph)
 	return ret;
 }
 
+struct scmi_imx_misc_syslog_ipriv {
+	u32 *array;
+	u16 *size;
+};
+
+static void iter_misc_syslog_prepare_message(void *message, u32 desc_index,
+					     const void *priv)
+{
+	struct scmi_imx_misc_syslog_in *msg = message;
+
+	msg->flags = cpu_to_le32(0);
+	msg->index = cpu_to_le32(desc_index);
+}
+
+static int iter_misc_syslog_update_state(struct scmi_iterator_state *st,
+					 const void *response, void *priv)
+{
+	const struct scmi_imx_misc_syslog_out *r = response;
+	struct scmi_imx_misc_syslog_ipriv *p = priv;
+
+	st->num_returned = RETURNED(r->numlogflags);
+	st->num_remaining = REMAINING(r->numlogflags);
+	*p->size = st->num_returned + st->num_remaining;
+
+	return 0;
+}
+
+static int
+iter_misc_syslog_process_response(const struct scmi_protocol_handle *ph,
+				  const void *response,
+				  struct scmi_iterator_state *st, void *priv)
+{
+	const struct scmi_imx_misc_syslog_out *r = response;
+	struct scmi_imx_misc_syslog_ipriv *p = priv;
+
+	p->array[st->desc_index + st->loop_idx] =
+		le32_to_cpu(r->syslog[st->loop_idx]);
+
+	return 0;
+}
+
+static int scmi_imx_misc_syslog_get(const struct scmi_protocol_handle *ph, u16 *size,
+				    void *array)
+{
+	struct scmi_iterator_ops ops = {
+		.prepare_message = iter_misc_syslog_prepare_message,
+		.update_state = iter_misc_syslog_update_state,
+		.process_response = iter_misc_syslog_process_response,
+	};
+	struct scmi_imx_misc_syslog_ipriv ipriv = {
+		.array = array,
+		.size = size,
+	};
+	void *iter;
+
+	if (!array || !size || !*size)
+		return -EINVAL;
+
+	iter = ph->hops->iter_response_init(ph, &ops, *size, SCMI_IMX_MISC_SYSLOG_GET,
+					    sizeof(struct scmi_imx_misc_syslog_in),
+					    &ipriv);
+	if (IS_ERR(iter))
+		return PTR_ERR(iter);
+
+	/* If firmware return NOT SUPPORTED, propagate value to caller */
+	return ph->hops->iter_response_run(iter);
+}
+
 static const struct scmi_imx_misc_proto_ops scmi_imx_misc_proto_ops = {
 	.misc_ctrl_set = scmi_imx_misc_ctrl_set,
 	.misc_ctrl_get = scmi_imx_misc_ctrl_get,
 	.misc_ctrl_req_notify = scmi_imx_misc_ctrl_notify,
+	.misc_syslog = scmi_imx_misc_syslog_get,
 };
 
 static int scmi_imx_misc_protocol_init(const struct scmi_protocol_handle *ph)
diff --git a/include/linux/scmi_imx_protocol.h b/include/linux/scmi_imx_protocol.h
index 27bd372cbfb142b6acb0b1cf4b82f061529d0d45..2407d7693b6ba1303e07629e45e2a7eaaa906fd3 100644
--- a/include/linux/scmi_imx_protocol.h
+++ b/include/linux/scmi_imx_protocol.h
@@ -59,6 +59,8 @@ struct scmi_imx_misc_proto_ops {
 			     u32 *num, u32 *val);
 	int (*misc_ctrl_req_notify)(const struct scmi_protocol_handle *ph,
 				    u32 ctrl_id, u32 evt_id, u32 flags);
+	int (*misc_syslog)(const struct scmi_protocol_handle *ph, u16 *size,
+			   void *array);
 };
 
 /* See LMM_ATTRIBUTES in imx95.rst */

-- 
2.37.1