[PATCH v3 13/28] soc: qcom: Add driver for Qualcomm Krait L2 cache scaling

Dmitry Baryshkov
2023-07-02T17:43:50Z

Add a simple driver that handles scaling of L2 frequency and voltages.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
---
drivers/soc/qcom/Kconfig | 9 ++
drivers/soc/qcom/Makefile | 1 +
drivers/soc/qcom/krait-l2-cache.c | 167 ++++++++++++++++++++++++++++++
3 files changed, 177 insertions(+)
create mode 100644 drivers/soc/qcom/krait-l2-cache.c

diff --git a/drivers/soc/qcom/Kconfig b/drivers/soc/qcom/Kconfig
index e597799e8121..01090b7a3c06 100644
--- a/drivers/soc/qcom/Kconfig
+++ b/drivers/soc/qcom/Kconfig
@@ -70,6 +70,15 @@ config QCOM_LLCC
SDM845. This provides interfaces to clients that use the LLCC.
Say yes here to enable LLCC slice driver.

+config QCOM_KRAIT_L2_CACHE
+ tristate "Qualcomm Krait L2 cache scaling"
+ depends on ARCH_QCOM && ARM || COMPILE_TEST
+ select INTERCONNECT
+ select INTERCONNECT_CLK
+ default ARM_QCOM_CPUFREQ_NVMEM
+ help
+ The driver for scaling the L2 cache frequency on Qualcomm Krait platforms.
+
config QCOM_KRYO_L2_ACCESSORS
bool
depends on (ARCH_QCOM || COMPILE_TEST) && ARM64
diff --git a/drivers/soc/qcom/Makefile b/drivers/soc/qcom/Makefile
index 99114c71092b..cdd1cc96e9f9 100644
--- a/drivers/soc/qcom/Makefile
+++ b/drivers/soc/qcom/Makefile
@@ -31,6 +31,7 @@ obj-$(CONFIG_QCOM_APR) += apr.o
obj-$(CONFIG_QCOM_LLCC) += llcc-qcom.o
obj-$(CONFIG_QCOM_RPMHPD) += rpmhpd.o
obj-$(CONFIG_QCOM_RPMPD) += rpmpd.o
+obj-$(CONFIG_QCOM_KRAIT_L2_CACHE) += krait-l2-cache.o
obj-$(CONFIG_QCOM_KRYO_L2_ACCESSORS) += kryo-l2-accessors.o
obj-$(CONFIG_QCOM_ICC_BWMON) += icc-bwmon.o
qcom_ice-objs += ice.o
diff --git a/drivers/soc/qcom/krait-l2-cache.c b/drivers/soc/qcom/krait-l2-cache.c
new file mode 100644
index 000000000000..c493da50ab65
--- /dev/null
+++ b/drivers/soc/qcom/krait-l2-cache.c
@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2023, Linaro Ltd.
+ */
+
+#include <linux/clk.h>
+#include <linux/interconnect-clk.h>
+#include <linux/interconnect-provider.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/regulator/consumer.h>
+
+#include <dt-bindings/soc/qcom,krait-l2-cache.h>
+
+/* Random ID that doesn't clash with main qnoc and OSM */
+#define L2_MASTER_NODE 2000
+
+static int krait_l2_set_one_supply(struct device *dev,
+ struct regulator *reg,
+ struct dev_pm_opp_supply *supply)
+{
+ int ret;
+
+ dev_dbg(dev, "%s: voltages (mV): %lu %lu %lu\n", __func__,
+ supply->u_volt_min, supply->u_volt, supply->u_volt_max);
+
+ ret = regulator_set_voltage_triplet(reg,
+ supply->u_volt_min,
+ supply->u_volt,
+ supply->u_volt_max);
+ if (ret) {
+ dev_err(dev, "%s: failed to set voltage (%lu %lu %lu mV): %d\n",
+ __func__, supply->u_volt_min, supply->u_volt,
+ supply->u_volt_max, ret);
+ return ret;
+ }
+
+ return 0;
+}
+
+/* vdd-mem and vdd-dig */
+#define NUM_SUPPLIES 2
+static int krait_l2_config_regulators(struct device *dev,
+ struct dev_pm_opp *old_opp,
+ struct dev_pm_opp *new_opp,
+ struct regulator **regulators,
+ unsigned int count)
+{
+ struct dev_pm_opp_supply supplies[NUM_SUPPLIES];
+ unsigned long old_freq, freq;
+ unsigned int i;
+ int ret;
+
+ if (WARN_ON_ONCE(count != NUM_SUPPLIES))
+ return -EINVAL;
+
+ ret = dev_pm_opp_get_supplies(new_opp, supplies);
+ if (WARN_ON(ret))
+ return ret;
+
+ old_freq = dev_pm_opp_get_freq(old_opp);
+ freq = dev_pm_opp_get_freq(new_opp);
+
+ WARN_ON(!old_freq || !freq);
+ if (freq > old_freq) {
+ for (i = 0; i < count; i++) {
+ ret = krait_l2_set_one_supply(dev, regulators[i], &supplies[i]);
+ if (ret)
+ goto restore_backwards;
+ }
+ } else {
+ for (i = count; i > 0; i--) {
+ ret = krait_l2_set_one_supply(dev, regulators[i - 1], &supplies[i - 1]);
+ if (ret)
+ goto restore_forward;
+ }
+ }
+
+ return 0;
+
+restore_backwards:
+
+ dev_pm_opp_get_supplies(old_opp, supplies);
+
+ for (; i > 0; i--)
+ krait_l2_set_one_supply(dev, regulators[i - 1], &supplies[i - 1]);
+
+ return ret;
+
+restore_forward:
+
+ dev_pm_opp_get_supplies(old_opp, supplies);
+
+ for ( ; i < count; i++)
+ krait_l2_set_one_supply(dev, regulators[i], &supplies[i]);
+
+ return ret;
+}
+
+static int krait_l2_probe(struct platform_device *pdev)
+{
+ struct dev_pm_opp_config krait_l2_cfg = {
+ .clk_names = (const char * const[]) { NULL, NULL },
+ .config_regulators = krait_l2_config_regulators,
+ .regulator_names = (const char * const[]) { "vdd-mem", "vdd-dig", NULL },
+ };
+ struct icc_clk_data data[] = {
+ { .name = "l2", .opp = true},
+ };
+
+ struct device *dev = &pdev->dev;
+ struct icc_provider *provider;
+ struct clk *clk;
+ int ret;
+
+ clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(clk))
+ return PTR_ERR(clk);
+
+ ret = devm_pm_opp_set_config(dev, &krait_l2_cfg);
+ if (ret)
+ return ret;
+
+ ret = devm_pm_opp_of_add_table(dev);
+ if (ret)
+ return ret;
+
+ data[0].clk = clk;
+ provider = icc_clk_register(dev, L2_MASTER_NODE, ARRAY_SIZE(data), data);
+ if (IS_ERR(provider))
+ return PTR_ERR(provider);
+
+ platform_set_drvdata(pdev, provider);
+
+ return 0;
+}
+
+static int krait_l2_remove(struct platform_device *pdev)
+{
+ struct icc_provider *provider = platform_get_drvdata(pdev);
+
+ icc_clk_unregister(provider);
+
+ return 0;
+}
+
+static const struct of_device_id krait_l2_match_table[] = {
+ { .compatible = "qcom,krait-l2-cache" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, krait_l2_match_table);
+
+static struct platform_driver krait_l2_driver = {
+ .probe = krait_l2_probe,
+ .remove = krait_l2_remove,
+ .driver = {
+ .name = "qcom-krait-l2",
+ .of_match_table = krait_l2_match_table,
+ .sync_state = icc_sync_state,
+ },
+};
+
+module_platform_driver(krait_l2_driver);
+
+MODULE_DESCRIPTION("Qualcomm Krait L2 scaling driver");
+MODULE_LICENSE("GPL v2");
--
2.39.2