soc/qcom: rpmh: add RPMh read

Implement support for RPMh reads, these allow reading out the
current votes for RPMh controlled resources such as regulators and
interconnects.

Link: https://patch.msgid.link/20260108-rpmh-regulator-fixes-v1-4-d1b5b300b665@linaro.org
Signed-off-by: Casey Connolly <casey.connolly@linaro.org>

diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
index 05fff174f8329ae0a6513f979f38a1822c65aa17..dce61f262292e390987902f8490f2bb31e3c8648 100644 (file)
--- a/drivers/soc/qcom/rpmh-rsc.c
+++ b/drivers/soc/qcom/rpmh-rsc.c
@@ -282,12 +282,15 @@ static void __tcs_buffer_write(struct rsc_drv *drv, int tcs_id, int cmd_id,
                               const struct tcs_request *msg)
 {
        u32 msgid;
-       u32 cmd_msgid = CMD_MSGID_LEN | CMD_MSGID_WRITE;
+       u32 cmd_msgid = CMD_MSGID_LEN;
        u32 cmd_enable = 0;
        u32 cmd_complete = 0;
        struct tcs_cmd *cmd;
        int i, j;
 
+       if (!msg->is_read)
+               cmd_msgid |= CMD_MSGID_WRITE;
+
        if (msg->wait_for_compl)
                cmd_msgid |= CMD_MSGID_RESP_REQ;
 
@@ -302,7 +305,8 @@ static void __tcs_buffer_write(struct rsc_drv *drv, int tcs_id, int cmd_id,
 
                write_tcs_cmd(drv, drv->regs[RSC_DRV_CMD_MSGID], tcs_id, j, msgid);
                write_tcs_cmd(drv, drv->regs[RSC_DRV_CMD_ADDR], tcs_id, j, cmd->addr);
-               write_tcs_cmd(drv, drv->regs[RSC_DRV_CMD_DATA], tcs_id, j, cmd->data);
+               if (!msg->is_read)
+                       write_tcs_cmd(drv, drv->regs[RSC_DRV_CMD_DATA], tcs_id, j, cmd->data);
                debug("tcs(%d): [%s] cmd_id: %d: msgid: %#x addr: %#x data: %#x complete: %#x\n",
                      tcs_id, msg->state == RPMH_ACTIVE_ONLY_STATE ? "active" : "?", j, msgid,
                      cmd->addr, cmd->data, cmd_complete);
@@ -418,6 +422,12 @@ int rpmh_rsc_send_data(struct rsc_drv *drv, const struct tcs_request *msg)
                udelay(1);
        }
 
+       /* U-Boot: read the response now we know it's available */
+       if (msg->is_read) {
+               msg->cmds[0].data = read_tcs_cmd(drv, drv->regs[RSC_DRV_CMD_RESP_DATA], tcs_id, 0);
+               log_debug("data response: %#x\n", msg->cmds[0].data);
+       }
+
        __tcs_set_trigger(drv, tcs_id, false);
 
        /* Reclaim the TCS */

diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
index 91b90626af36ae2961371b6e2668985374a66dfb..8c222324c66d7fc5388a7fc3d51b8dc1232cd254 100644 (file)
--- a/drivers/soc/qcom/rpmh.c
+++ b/drivers/soc/qcom/rpmh.c
@@ -68,7 +68,7 @@ static int __rpmh_write(const struct udevice *dev, enum rpmh_state state,
 }
 
 static int __fill_rpmh_msg(struct rpmh_request *req, enum rpmh_state state,
-                          const struct tcs_cmd *cmd, u32 n)
+                          const struct tcs_cmd *cmd, u32 n, bool is_read)
 {
        if (!cmd || !n || n > MAX_RPMH_PAYLOAD)
                return -EINVAL;
@@ -78,12 +78,45 @@ static int __fill_rpmh_msg(struct rpmh_request *req, enum rpmh_state state,
        req->msg.state = state;
        req->msg.cmds = req->cmd;
        req->msg.num_cmds = n;
+       req->msg.is_read = is_read;
 
        debug("rpmh_msg: %d, %d cmds [first %#x/%#x]\n", state, n, cmd->addr, cmd->data);
 
        return 0;
 }
 
+/**
+ * rpmh_read: Read a resource value
+ *
+ * @dev: The device making the request
+ * @cmd: The payload having address of resource to read
+ *
+ * Reads the value for the resource address given in tcs_cmd->addr
+ * and returns the tcs_cmd->data filled with same.
+ *
+ * May sleep. Do not call from atomic contexts.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+int rpmh_read(const struct udevice *dev, enum rpmh_state state, struct tcs_cmd *cmd)
+{
+       DEFINE_RPMH_MSG_ONSTACK(dev, state, rpm_msg);
+       int ret;
+
+       ret = __fill_rpmh_msg(&rpm_msg, state, cmd, 1, true);
+       if (ret)
+               return ret;
+
+       ret = __rpmh_write(dev, state, &rpm_msg);
+       if (ret)
+               return ret;
+
+       /* Read back the response into the cmd data structure */
+       cmd->data = rpm_msg.cmd[0].data;
+
+       return (ret > 0) ? 0 : ret;
+}
+
 /**
  * rpmh_write: Write a set of RPMH commands and block until response
  *
@@ -100,7 +133,7 @@ int rpmh_write(const struct udevice *dev, enum rpmh_state state,
        DEFINE_RPMH_MSG_ONSTACK(dev, state, rpm_msg);
        int ret;
 
-       ret = __fill_rpmh_msg(&rpm_msg, state, cmd, n);
+       ret = __fill_rpmh_msg(&rpm_msg, state, cmd, n, false);
        if (ret)
                return ret;
 

diff --git a/include/soc/qcom/rpmh.h b/include/soc/qcom/rpmh.h
index 3421fbf1ee3e491a45ffc6b1355ff1e7a0be6f86..40812a315bc19e571ab6c5db673d2b9c893e7913 100644 (file)
--- a/include/soc/qcom/rpmh.h
+++ b/include/soc/qcom/rpmh.h
@@ -13,12 +13,14 @@
 #if IS_ENABLED(CONFIG_QCOM_RPMH)
 int rpmh_write(const struct udevice *dev, enum rpmh_state state,
               const struct tcs_cmd *cmd, u32 n);
-
+int rpmh_read(const struct udevice *dev, enum rpmh_state state, struct tcs_cmd *cmd);
 #else
 
 static inline int rpmh_write(const struct device *dev, enum rpmh_state state,
                             const struct tcs_cmd *cmd, u32 n)
 { return -ENODEV; }
+static inline int rpmh_read(const struct udevice *dev, struct tcs_cmd *cmd)
+{ return -ENODEV; }
 
 #endif /* CONFIG_QCOM_RPMH */
 

diff --git a/include/soc/qcom/tcs.h b/include/soc/qcom/tcs.h
index 3acca067c72b14396f273a65baf9c52868ab2348..22bafe2598a0450c5b659342a0c431e60d05a9a4 100644 (file)
--- a/include/soc/qcom/tcs.h
+++ b/include/soc/qcom/tcs.h
@@ -55,6 +55,7 @@ struct tcs_cmd {
  */
 struct tcs_request {
        enum rpmh_state state;
+       bool is_read;
        u32 wait_for_compl;
        u32 num_cmds;
        struct tcs_cmd *cmds;