From: Maulik Shah <maulik.shah@oss.qualcomm.com>
All rpmh_*() APIs so far have supported placing votes for various
resource settings but the H/W also have option to read resource
settings.
This change adds a new rpmh_read() API to allow clients
to read back resource setting from H/W. This will be useful for
clients like regulators, which currently don't have a way to know
the settings applied during bootloader stage.
Link: https://lore.kernel.org/r/20250623-add-rpmh-read-support-v1-1-ae583d260195@oss.qualcomm.com
Signed-off-by: Maulik Shah <maulik.shah@oss.qualcomm.com>
Signed-off-by: Kamal Wadhwa <kamal.wadhwa@oss.qualcomm.com>
---
drivers/soc/qcom/rpmh-rsc.c | 13 +++++++++++--
drivers/soc/qcom/rpmh.c | 47 +++++++++++++++++++++++++++++++++++++++++----
include/soc/qcom/rpmh.h | 5 +++++
include/soc/qcom/tcs.h | 2 ++
4 files changed, 61 insertions(+), 6 deletions(-)
diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
index c6f7d5c9c493d9e06c048930b8a14a38660df4b1..ec85c457ea4527f94339c2033bfcc12346e3c443 100644
--- a/drivers/soc/qcom/rpmh-rsc.c
+++ b/drivers/soc/qcom/rpmh-rsc.c
@@ -443,6 +443,7 @@ static irqreturn_t tcs_tx_done(int irq, void *p)
int i;
unsigned long irq_status;
const struct tcs_request *req;
+ u32 reg;
irq_status = readl_relaxed(drv->tcs_base + drv->regs[RSC_DRV_IRQ_STATUS]);
@@ -453,6 +454,11 @@ static irqreturn_t tcs_tx_done(int irq, void *p)
trace_rpmh_tx_done(drv, i, req);
+ if (req->is_read) {
+ reg = drv->regs[RSC_DRV_CMD_RESP_DATA];
+ req->cmds[0].data = read_tcs_reg(drv, reg, i);
+ }
+
/* Clear AMC trigger & enable modes and
* disable interrupt for this TCS
*/
@@ -493,13 +499,15 @@ 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;
struct tcs_cmd *cmd;
int i, j;
/* Convert all commands to RR when the request has wait_for_compl set */
cmd_msgid |= msg->wait_for_compl ? CMD_MSGID_RESP_REQ : 0;
+ if (!msg->is_read)
+ cmd_msgid |= CMD_MSGID_WRITE;
for (i = 0, j = cmd_id; i < msg->num_cmds; i++, j++) {
cmd = &msg->cmds[i];
@@ -513,7 +521,8 @@ 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);
trace_rpmh_send_msg(drv, tcs_id, msg->state, j, msgid, cmd);
}
diff --git a/drivers/soc/qcom/rpmh.c b/drivers/soc/qcom/rpmh.c
index 8903ed956312d0a2ac7f673d86ef504947e9b119..4a611dac437ef28bac124583073c87a79e9e5cad 100644
--- a/drivers/soc/qcom/rpmh.c
+++ b/drivers/soc/qcom/rpmh.c
@@ -175,6 +175,9 @@ static int __rpmh_write(const struct device *dev, enum rpmh_state state,
struct cache_req *req;
int i;
+ if (rpm_msg->msg.is_read)
+ goto send_data;
+
/* Cache the request in our store and link the payload */
for (i = 0; i < rpm_msg->msg.num_cmds; i++) {
req = cache_rpm_request(ctrlr, state, &rpm_msg->msg.cmds[i]);
@@ -182,6 +185,7 @@ static int __rpmh_write(const struct device *dev, enum rpmh_state state,
return PTR_ERR(req);
}
+send_data:
if (state == RPMH_ACTIVE_ONLY_STATE) {
ret = rpmh_rsc_send_data(ctrlr_to_drv(ctrlr), &rpm_msg->msg);
} else {
@@ -194,7 +198,7 @@ static int __rpmh_write(const struct device *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;
@@ -204,10 +208,45 @@ 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;
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 device *dev, struct tcs_cmd *cmd)
+{
+ DECLARE_COMPLETION_ONSTACK(compl);
+ DEFINE_RPMH_MSG_ONSTACK(dev, RPMH_ACTIVE_ONLY_STATE, &compl, rpm_msg);
+ int ret;
+
+ ret = __fill_rpmh_msg(&rpm_msg, RPMH_ACTIVE_ONLY_STATE, cmd, 1, true);
+ if (ret)
+ return ret;
+
+ ret = __rpmh_write(dev, RPMH_ACTIVE_ONLY_STATE, &rpm_msg);
+ if (ret)
+ return ret;
+
+ ret = wait_for_completion_timeout(&compl, RPMH_TIMEOUT_MS);
+ cmd[0].data = rpm_msg.cmd[0].data;
+
+ return (ret > 0) ? 0 : -ETIMEDOUT;
+}
+EXPORT_SYMBOL_GPL(rpmh_read);
+
/**
* rpmh_write_async: Write a set of RPMH commands
*
@@ -230,7 +269,7 @@ int rpmh_write_async(const struct device *dev, enum rpmh_state state,
return -ENOMEM;
rpm_msg->needs_free = true;
- ret = __fill_rpmh_msg(rpm_msg, state, cmd, n);
+ ret = __fill_rpmh_msg(rpm_msg, state, cmd, n, false);
if (ret) {
kfree(rpm_msg);
return ret;
@@ -257,7 +296,7 @@ int rpmh_write(const struct device *dev, enum rpmh_state state,
DEFINE_RPMH_MSG_ONSTACK(dev, state, &compl, 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;
@@ -352,7 +391,7 @@ int rpmh_write_batch(const struct device *dev, enum rpmh_state state,
rpm_msgs = req->rpm_msgs;
for (i = 0; i < count; i++) {
- __fill_rpmh_msg(rpm_msgs + i, state, cmd, n[i]);
+ __fill_rpmh_msg(rpm_msgs + i, state, cmd, n[i], false);
cmd += n[i];
}
diff --git a/include/soc/qcom/rpmh.h b/include/soc/qcom/rpmh.h
index bdbee1a97d3685d8a6153d586ddf650bd3bd3dde..14ecbf242b6bd67c8167c176ed0970f42432f4f4 100644
--- a/include/soc/qcom/rpmh.h
+++ b/include/soc/qcom/rpmh.h
@@ -11,6 +11,8 @@
#if IS_ENABLED(CONFIG_QCOM_RPMH)
+int rpmh_read(const struct device *dev, struct tcs_cmd *cmd);
+
int rpmh_write(const struct device *dev, enum rpmh_state state,
const struct tcs_cmd *cmd, u32 n);
@@ -24,6 +26,9 @@ void rpmh_invalidate(const struct device *dev);
#else
+static inline int rpmh_read(const struct device *dev, struct tcs_cmd *cmd)
+{ return -ENODEV; }
+
static inline int rpmh_write(const struct device *dev, enum rpmh_state state,
const struct tcs_cmd *cmd, u32 n)
{ return -ENODEV; }
diff --git a/include/soc/qcom/tcs.h b/include/soc/qcom/tcs.h
index cff67ce25488e2d3603a7707af2ca77f8266a713..45b8513be2f9bb0957796476f6031146ee34e931 100644
--- a/include/soc/qcom/tcs.h
+++ b/include/soc/qcom/tcs.h
@@ -51,6 +51,7 @@ struct tcs_cmd {
* struct tcs_request: A set of tcs_cmds sent together in a TCS
*
* @state: state for the request.
+ * @is_read: set for read only requests
* @wait_for_compl: wait until we get a response from the h/w accelerator
* (same as setting cmd->wait for all commands in the request)
* @num_cmds: the number of @cmds in this request
@@ -58,6 +59,7 @@ struct tcs_cmd {
*/
struct tcs_request {
enum rpmh_state state;
+ bool is_read;
u32 wait_for_compl;
u32 num_cmds;
struct tcs_cmd *cmds;
--
2.25.1On Wed, Oct 22, 2025 at 02:38:54AM +0530, Kamal Wadhwa wrote: > From: Maulik Shah <maulik.shah@oss.qualcomm.com> > > All rpmh_*() APIs so far have supported placing votes for various > resource settings but the H/W also have option to read resource > settings. Is it supported since SDM845? > > This change adds a new rpmh_read() API to allow clients See Documentation/process/submitting-patches.rst, "This patch ..." > to read back resource setting from H/W. This will be useful for > clients like regulators, which currently don't have a way to know > the settings applied during bootloader stage. > > Link: https://lore.kernel.org/r/20250623-add-rpmh-read-support-v1-1-ae583d260195@oss.qualcomm.com This is useless, please drop. > Signed-off-by: Maulik Shah <maulik.shah@oss.qualcomm.com> > Signed-off-by: Kamal Wadhwa <kamal.wadhwa@oss.qualcomm.com> > --- > drivers/soc/qcom/rpmh-rsc.c | 13 +++++++++++-- > drivers/soc/qcom/rpmh.c | 47 +++++++++++++++++++++++++++++++++++++++++---- > include/soc/qcom/rpmh.h | 5 +++++ > include/soc/qcom/tcs.h | 2 ++ > 4 files changed, 61 insertions(+), 6 deletions(-) > -- With best wishes Dmitry
On 10/22/2025 3:58 AM, Dmitry Baryshkov wrote: > On Wed, Oct 22, 2025 at 02:38:54AM +0530, Kamal Wadhwa wrote: >> From: Maulik Shah <maulik.shah@oss.qualcomm.com> >> >> All rpmh_*() APIs so far have supported placing votes for various >> resource settings but the H/W also have option to read resource >> settings. > > Is it supported since SDM845? Yes, H/W supports reads since SDM845.> >> >> This change adds a new rpmh_read() API to allow clients > > See Documentation/process/submitting-patches.rst, "This patch ..." I will address in next revision. > >> to read back resource setting from H/W. This will be useful for >> clients like regulators, which currently don't have a way to know >> the settings applied during bootloader stage. >> >> Link: https://lore.kernel.org/r/20250623-add-rpmh-read-support-v1-1-ae583d260195@oss.qualcomm.com > > This is useless, please drop. I will address in next revision. Thanks, Maulik > >> Signed-off-by: Maulik Shah <maulik.shah@oss.qualcomm.com> >> Signed-off-by: Kamal Wadhwa <kamal.wadhwa@oss.qualcomm.com> >> --- >> drivers/soc/qcom/rpmh-rsc.c | 13 +++++++++++-- >> drivers/soc/qcom/rpmh.c | 47 +++++++++++++++++++++++++++++++++++++++++---- >> include/soc/qcom/rpmh.h | 5 +++++ >> include/soc/qcom/tcs.h | 2 ++ >> 4 files changed, 61 insertions(+), 6 deletions(-) >> >
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