Re: [PATCH 2/5] thermal: qcom: Add support for LMh driver

From: Thara Gopinath
Date: Mon Jun 14 2021 - 22:42:12 EST


Hi Randy,

Thanks for the review. I somehow did not see your review earlier. I noticed it today morning when Bjorn replied to this patch. Apologies for the delay

On 6/8/21 10:25 PM, Randy Dunlap wrote:
On 6/8/21 3:29 PM, Thara Gopinath wrote:
Driver enabling various pieces of Limits Management Hardware(LMh) for cpu
cluster0 and cpu cluster1 namely kick starting monitoring of temperature,
current, battery current violations, enabling reliability algorithm and
setting up various temperature limits.

The following has been explained in the cover letter. I am including this
here so that this remains in the commit message as well.

LMh is a hardware infrastructure on some Qualcomm SoCs that can enforce
temperature and current limits as programmed by software for certain IPs
like CPU. On many newer SoCs LMh is configured by firmware/TZ and no
programming is needed from the kernel side. But on certain SoCs like sdm845
the firmware does not do a complete programming of the h/w. On such SoCs
kernel software has to explicitly set up the temperature limits and turn on
various monitoring and enforcing algorithms on the hardware.

Signed-off-by: Thara Gopinath <thara.gopinath@xxxxxxxxxx>
---
drivers/thermal/qcom/Kconfig | 10 ++
drivers/thermal/qcom/Makefile | 1 +
drivers/thermal/qcom/lmh.c | 244 ++++++++++++++++++++++++++++++++++
3 files changed, 255 insertions(+)
create mode 100644 drivers/thermal/qcom/lmh.c

diff --git a/drivers/thermal/qcom/Kconfig b/drivers/thermal/qcom/Kconfig
index 8d5ac2df26dc..c95b95e254d7 100644
--- a/drivers/thermal/qcom/Kconfig
+++ b/drivers/thermal/qcom/Kconfig
@@ -31,3 +31,13 @@ config QCOM_SPMI_TEMP_ALARM
trip points. The temperature reported by the thermal sensor reflects the
real time die temperature if an ADC is present or an estimate of the
temperature based upon the over temperature stage value.
+
+config QCOM_LMH
+ tristate "Qualcomm Limits Management Hardware"
+ depends on ARCH_QCOM
+ help
+ This enables initialization of Qualcomm limits management
+ hardware(LMh). LMh allows for h/w enforced mitigation for cpus based on

hardware-enforced CPUs

+ input from temperature and current sensors. On many newer Qualcomm SoCs
+ LMH is configure in the firmware and this feature need not be enabled.

LMh

+ However, on certain SoCs like sdm845 LMH has to be configured from HLOS.

LMh

What is HLOS?

High Level Operating System. But I will change it to Linux kernel.


diff --git a/drivers/thermal/qcom/lmh.c b/drivers/thermal/qcom/lmh.c
new file mode 100644
index 000000000000..8741a36cb674
--- /dev/null
+++ b/drivers/thermal/qcom/lmh.c
@@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+/*
+ * Copyright (C) 2021, Linaro Limited. All rights reserved.
+ */

[snip]

+static int lmh_probe(struct platform_device *pdev)
+{
+ struct device *dev;
+ struct device_node *np;
+ struct lmh_hw_data *lmh_data;
+ u32 node_id;
+ int ret;
+
+ dev = &pdev->dev;
+ np = dev->of_node;
+ if (!np)
+ return -EINVAL;
+
+ lmh_data = devm_kzalloc(dev, sizeof(*lmh_data), GFP_KERNEL);
+ if (!lmh_data)
+ return -ENOMEM;
+
+ lmh_data->base = devm_platform_ioremap_resource(pdev, 0);
+ if (IS_ERR(lmh_data->base))
+ return PTR_ERR(lmh_data->base);
+
+ ret = of_property_read_u32(np, "qcom,lmh-cpu-id", &lmh_data->cpu_id);
+ if (ret)
+ return -ENODEV;
+
+ /*
+ * Only sdm845 has lmh hardware currently enabled from hlos. If this is needed
+ * for other platforms, revisit this to check if the <cpu-id, node-id> should be part
+ * of a dt match table.
+ */
+ if (lmh_data->cpu_id == 0) {
+ node_id = LMH_CLUSTER0_NODE_ID;
+ } else if (lmh_data->cpu_id == 4) {
+ node_id = LMH_CLUSTER1_NODE_ID;
+ } else {
+ dev_err(dev, "Wrong cpu id associated with lmh node\n");

CPU LMh

will fix it. Also will fix all the typos you have caught below.


+ return -EINVAL;
+ }
+
+ /* Payload size is five bytes for now */
+ lmh_data->payload_size = 5 * sizeof(u32);
+
+ platform_set_drvdata(pdev, lmh_data);
+
+ if (!qcom_scm_lmh_dcvsh_available())
+ return -EINVAL;
+
+ /* Enable Thermal Algorithm */
+ update_payload(lmh_data, LMH_SUB_FN_THERMAL, LMH_ALGO_MODE_ENABLE, 1);
+ ret = qcom_scm_lmh_dcvsh(lmh_data->payload, lmh_data->payload_size,
+ LMH_NODE_DCVS, node_id, 0);
+ if (ret) {
+ dev_err(dev, "Error %d enabling thermal subfunction\n", ret);
+ return ret;
+ }
+
+ /* Enable Current Sensing Algorithm */
+ update_payload(lmh_data, LMH_SUB_FN_CRNT, LMH_ALGO_MODE_ENABLE, 1);
+ ret = qcom_scm_lmh_dcvsh(lmh_data->payload, lmh_data->payload_size,
+ LMH_NODE_DCVS, node_id, 0);
+ if (ret) {
+ dev_err(dev, "Error %d enabling current subfunction\n", ret);
+ return ret;
+ }
+
+ /* Enable Reliability Algorithm */
+ update_payload(lmh_data, LMH_SUB_FN_REL, LMH_ALGO_MODE_ENABLE, 1);
+ ret = qcom_scm_lmh_dcvsh(lmh_data->payload, lmh_data->payload_size,
+ LMH_NODE_DCVS, node_id, 0);
+ if (ret) {
+ dev_err(dev, "Error %d enabling reliability subfunction\n", ret);
+ return ret;
+ }
+
+ /* Enable BCL Algorithm */
+ update_payload(lmh_data, LMH_SUB_FN_BCL, LMH_ALGO_MODE_ENABLE, 1);
+ ret = qcom_scm_lmh_dcvsh(lmh_data->payload, lmh_data->payload_size,
+ LMH_NODE_DCVS, node_id, 0);
+ if (ret) {
+ dev_err(dev, "Error %d enabling BCL subfunction\n", ret);

What is BCL?

Battery Current Limits

--
Warm Regards
Thara

+ return ret;
+ }
+
+ ret = qcom_scm_lmh_profile_change(0x1);
+ if (ret) {
+ dev_err(dev, "Error %d changing profile\n", ret);
+ return ret;
+ }
+
+ /* Set default thermal trips */
+ update_payload(lmh_data, LMH_SUB_FN_THERMAL, LMH_TH_ARM_THRESHOLD, LMH_TH_ARM_TEMP);
+ ret = qcom_scm_lmh_dcvsh(lmh_data->payload, lmh_data->payload_size,
+ LMH_NODE_DCVS, node_id, 0);
+ if (ret) {
+ dev_err(dev, "Error setting thermal ARM thershold%d\n", ret);

threshold

+ return ret;
+ }
+
+ update_payload(lmh_data, LMH_SUB_FN_THERMAL, LMH_TH_HI_THRESHOLD, LMH_TH_HI_TEMP);
+ ret = qcom_scm_lmh_dcvsh(lmh_data->payload, lmh_data->payload_size,
+ LMH_NODE_DCVS, node_id, 0);
+ if (ret) {
+ dev_err(dev, "Error setting thermal HI thershold%d\n", ret);

threshold

+ return ret;
+ }
+ update_payload(lmh_data, LMH_SUB_FN_THERMAL, LMH_TH_LOW_THRESHOLD, LMH_TH_LOW_TEMP);
+ ret = qcom_scm_lmh_dcvsh(lmh_data->payload, lmh_data->payload_size,
+ LMH_NODE_DCVS, node_id, 0);
+ if (ret) {
+ dev_err(dev, "Error setting thermal ARM thershold%d\n", ret);

threshold

+ return ret;
+ }
+
+ lmh_data->irq = platform_get_irq(pdev, 0);
+ lmh_data->domain = irq_domain_add_linear(np, 1, &lmh_irq_ops, lmh_data);
+ if (!lmh_data->domain) {
+ dev_err(dev, "Error adding irq_domain\n");
+ return -EINVAL;
+ }
+
+ ret = devm_request_irq(dev, lmh_data->irq, lmh_handle_irq,
+ IRQF_TRIGGER_HIGH | IRQF_ONESHOT | IRQF_NO_SUSPEND,
+ "lmh-irq", lmh_data);
+ if (ret) {
+ dev_err(dev, "Error %d registering irq %x\n", ret, lmh_data->irq);
+ irq_domain_remove(lmh_data->domain);
+ return ret;
+ }
+ return 0;
+}
+
+static const struct of_device_id lmh_table[] = {
+ { .compatible = "qcom,msm-hw-limits", },
+ {},
+};
+
+static struct platform_driver lmh_driver = {
+ .probe = lmh_probe,
+ .driver = {
+ .name = "qcom-lmh",
+ .of_match_table = lmh_table,
+ },
+};
+module_platform_driver(lmh_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("QCOM LMH driver");

LMh


thanks.