Re: [PATCH v5 1/5] firmware: arm_scmi: Add Voltage Domain Support
From: Sudeep Holla <hidden>
Date: 2020-11-19 16:08:35
Also in:
linux-arm-kernel, lkml
On Tue, Nov 17, 2020 at 12:34:11PM +0000, Cristian Marussi wrote:
quoted hunk ↗ jump to hunk
Add SCMI Voltage Domain protocol support. Signed-off-by: Cristian Marussi <cristian.marussi@arm.com> --- v4 --> v5 - removed inline - moved segmented intervals defines - fixed some macros complaints by checkpatch v3 --> v4 - avoid fixed sized typing in voltage_info - avoid coccinelle falde complaints about pointer-sized allocations v2 --> v3 - restrict segmented voltage domain descriptors to one triplet - removed unneeded inline - free allocated resources for invalid voltage domain - added __must_check to info_get voltage operations - added a few comments - removed fixed size typing from struct voltage_info v1 --> v2 - fix voltage levels query loop to reload full cmd description between iterations as reported by Etienne Carriere - ensure rx buffer is properly sized calli scmi_reset_rx_to_maxsz between transfers --- drivers/firmware/arm_scmi/Makefile | 2 +- drivers/firmware/arm_scmi/common.h | 1 + drivers/firmware/arm_scmi/driver.c | 2 + drivers/firmware/arm_scmi/voltage.c | 397 ++++++++++++++++++++++++++++ include/linux/scmi_protocol.h | 64 +++++ 5 files changed, 465 insertions(+), 1 deletion(-) create mode 100644 drivers/firmware/arm_scmi/voltage.cdiff --git a/drivers/firmware/arm_scmi/Makefile b/drivers/firmware/arm_scmi/Makefile index bc0d54f8e861..6a2ef63306d6 100644 --- a/drivers/firmware/arm_scmi/Makefile +++ b/drivers/firmware/arm_scmi/Makefile@@ -4,7 +4,7 @@ scmi-driver-y = driver.o notify.o scmi-transport-y = shmem.o scmi-transport-$(CONFIG_MAILBOX) += mailbox.o scmi-transport-$(CONFIG_HAVE_ARM_SMCCC_DISCOVERY) += smc.o -scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o system.o +scmi-protocols-y = base.o clock.o perf.o power.o reset.o sensors.o system.o voltage.o scmi-module-objs := $(scmi-bus-y) $(scmi-driver-y) $(scmi-protocols-y) \ $(scmi-transport-y) obj-$(CONFIG_ARM_SCMI_PROTOCOL) += scmi-module.odiff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h index 65063fa948d4..c0fb45e7c3e8 100644 --- a/drivers/firmware/arm_scmi/common.h +++ b/drivers/firmware/arm_scmi/common.h@@ -169,6 +169,7 @@ DECLARE_SCMI_REGISTER_UNREGISTER(perf); DECLARE_SCMI_REGISTER_UNREGISTER(power); DECLARE_SCMI_REGISTER_UNREGISTER(reset); DECLARE_SCMI_REGISTER_UNREGISTER(sensors); +DECLARE_SCMI_REGISTER_UNREGISTER(voltage); DECLARE_SCMI_REGISTER_UNREGISTER(system); #define DEFINE_SCMI_PROTOCOL_REGISTER_UNREGISTER(id, name) \diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 3dfd8b6a0ebf..ada35e63feae 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c@@ -946,6 +946,7 @@ static int __init scmi_driver_init(void) scmi_power_register(); scmi_reset_register(); scmi_sensors_register(); + scmi_voltage_register(); scmi_system_register(); return platform_driver_register(&scmi_driver);@@ -961,6 +962,7 @@ static void __exit scmi_driver_exit(void) scmi_power_unregister(); scmi_reset_unregister(); scmi_sensors_unregister(); + scmi_voltage_unregister(); scmi_system_unregister(); platform_driver_unregister(&scmi_driver);diff --git a/drivers/firmware/arm_scmi/voltage.c b/drivers/firmware/arm_scmi/voltage.c new file mode 100644 index 000000000000..6b71589e0846 --- /dev/null +++ b/drivers/firmware/arm_scmi/voltage.c@@ -0,0 +1,397 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * System Control and Management Interface (SCMI) Voltage Protocol + * + * Copyright (C) 2020 ARM Ltd. + */ + +#include <linux/scmi_protocol.h> + +#include "common.h" + +#define VOLTAGE_DOMS_NUM_MASK GENMASK(15, 0) +#define REMAINING_LEVELS_MASK GENMASK(31, 16) +#define RETURNED_LEVELS_MASK GENMASK(11, 0) + +enum scmi_voltage_protocol_cmd { + VOLTAGE_DOMAIN_ATTRIBUTES = 0x3, + VOLTAGE_DESCRIBE_LEVELS = 0x4, + VOLTAGE_CONFIG_SET = 0x5, + VOLTAGE_CONFIG_GET = 0x6, + VOLTAGE_LEVEL_SET = 0x7, + VOLTAGE_LEVEL_GET = 0x8, +}; + +struct scmi_msg_resp_protocol_attributes { + __le32 attr; +#define NUM_VOLTAGE_DOMAINS(x) ((u16)(FIELD_GET(VOLTAGE_DOMS_NUM_MASK, (x)))) +}; +
Sorry but same annoying comment again, drop one element structures.
+struct scmi_msg_resp_domain_attributes {
+ __le32 attr;
+ u8 name[SCMI_MAX_STR_SIZE];
+};
+
+struct scmi_msg_cmd_describe_levels {
+ __le32 domain_id;
+ __le32 level_index;
+};
+
+struct scmi_msg_resp_describe_levels {
+ __le32 flags;
+#define NUM_REMAINING_LEVELS(f) ((u16)(FIELD_GET(REMAINING_LEVELS_MASK, (f))))
+#define NUM_RETURNED_LEVELS(f) ((u16)(FIELD_GET(RETURNED_LEVELS_MASK, (f))))
+#define SUPPORTS_SEGMENTED_LEVELS(f) ((f) & BIT(12))
+ __le32 voltage[];
+};
+
+struct scmi_msg_cmd_config_set {
+ __le32 domain_id;
+ __le32 config;
+};
+
+struct scmi_msg_cmd_level_set {
+ __le32 domain_id;
+ __le32 flags;
+ __le32 voltage_level;
+};
+
+struct voltage_info {
+ unsigned int version;
+ unsigned int num_domains;
+ struct scmi_voltage_info **domains;
+};
+
+static int scmi_protocol_attributes_get(const struct scmi_handle *handle,
+ struct voltage_info *vinfo)
+{
+ int ret;
+ struct scmi_xfer *t;
+ struct scmi_msg_resp_protocol_attributes *resp;
+
+ ret = scmi_xfer_get_init(handle, PROTOCOL_ATTRIBUTES,
+ SCMI_PROTOCOL_VOLTAGE, 0, sizeof(*resp), &t);
+ if (ret)
+ return ret;
+
+ resp = t->rx.buf;
+ ret = scmi_do_xfer(handle, t);
+ if (!ret)
+ vinfo->num_domains =
+ NUM_VOLTAGE_DOMAINS(le32_to_cpu(resp->attr));
+
+ scmi_xfer_put(handle, t);
+ return ret;
+}
+
+static int scmi_init_voltage_levels(struct device *dev,
+ struct scmi_voltage_info *v,
+ u32 flags, u32 num_returned,
+ u32 num_remaining)
+{
+ bool segmented;
+ u32 num_levels;
+Why can't you pass the above 2 directly from the caller to this function since they are just used to obtain them here. [...]
+static int scmi_voltage_descriptors_get(const struct scmi_handle *handle,
+ struct voltage_info *vinfo)
+{
+ int ret, dom;
+ struct scmi_xfer *td, *tl;
+ struct device *dev = handle->dev;
+ struct scmi_msg_resp_domain_attributes *resp_dom;
+ struct scmi_msg_resp_describe_levels *resp_levels;
+
+ ret = scmi_xfer_get_init(handle, VOLTAGE_DOMAIN_ATTRIBUTES,
+ SCMI_PROTOCOL_VOLTAGE, sizeof(__le32),
+ sizeof(*resp_dom), &td);
+ if (ret)
+ return ret;
+ resp_dom = td->rx.buf;
+
+ ret = scmi_xfer_get_init(handle, VOLTAGE_DESCRIBE_LEVELS,
+ SCMI_PROTOCOL_VOLTAGE, sizeof(__le64), 0, &tl);
+ if (ret)
+ goto outd;
+ resp_levels = tl->rx.buf;
+
+ for (dom = 0; dom < vinfo->num_domains; dom++) {
+ u32 desc_index = 0;
+ u16 num_returned = 0, num_remaining = 0;
+ struct scmi_msg_cmd_describe_levels *cmd;
+ struct scmi_voltage_info *v;
+
+ /* Retrieve domain attributes at first ... */
+ put_unaligned_le32(dom, td->tx.buf);
+ ret = scmi_do_xfer(handle, td);
+ /* Skip domain on comms error */
+ if (ret)
+ continue;
+
+ v = devm_kzalloc(dev, sizeof(*v), GFP_KERNEL);
+ if (!v) {
+ ret = -ENOMEM;
+ break;
+ }
+Why can't we allocate vinfo->domains real structure instead of pointers and indirection there ? I understand that it helps to manage holes easily but I think that would simplify the dynamic allocation and error handling. It doesn't have to be this complicated(not much but still) IMO. May be scmi_voltage_info_get can use num_levels to either return NULL or vinfo->domains[domain_id] ? Regards, Sudeep