From: "Hector.Yuan" <hector.yuan@xxxxxxxxxxxx>
Introduce cpufreq HW driver which can support
CPU frequency adjust in MT6779 platform.
Signed-off-by: Hector.Yuan <hector.yuan@xxxxxxxxxxxx>
---
drivers/cpufreq/Kconfig.arm | 12 ++
drivers/cpufreq/Makefile | 1 +
drivers/cpufreq/mediatek-cpufreq-hw.c | 340 +++++++++++++++++++++++++++++++++
3 files changed, 353 insertions(+)
create mode 100644 drivers/cpufreq/mediatek-cpufreq-hw.c
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index a5c5f70..954749a 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -133,6 +133,18 @@ config ARM_MEDIATEK_CPUFREQ
help
This adds the CPUFreq driver support for MediaTek SoCs.
+config ARM_MEDIATEK_CPUFREQ_HW
+ tristate "MediaTek CPUFreq HW driver"
+ depends on ARCH_MEDIATEK || COMPILE_TEST
+ default m
+ help
+ Support for the CPUFreq HW driver.
+ Some MediaTek chipsets have a HW engine to offload the steps
+ necessary for changing the frequency of the CPUs. Firmware loaded
+ in this engine exposes a programming interface to the OS.
+ The driver implements the cpufreq interface for this HW engine.
+ Say Y if you want to support CPUFreq HW.
+
config ARM_OMAP2PLUS_CPUFREQ
bool "TI OMAP2+"
depends on ARCH_OMAP2PLUS
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 27d3bd7..48ee585 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -56,6 +56,7 @@ obj-$(CONFIG_ARM_IMX6Q_CPUFREQ) += imx6q-cpufreq.o
obj-$(CONFIG_ARM_IMX_CPUFREQ_DT) += imx-cpufreq-dt.o
obj-$(CONFIG_ARM_KIRKWOOD_CPUFREQ) += kirkwood-cpufreq.o
obj-$(CONFIG_ARM_MEDIATEK_CPUFREQ) += mediatek-cpufreq.o
+obj-$(CONFIG_ARM_MEDIATEK_CPUFREQ_HW) += mediatek-cpufreq-hw.o
obj-$(CONFIG_MACH_MVEBU_V7) += mvebu-cpufreq.o
obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ) += omap-cpufreq.o
obj-$(CONFIG_ARM_PXA2xx_CPUFREQ) += pxa2xx-cpufreq.o
diff --git a/drivers/cpufreq/mediatek-cpufreq-hw.c b/drivers/cpufreq/mediatek-cpufreq-hw.c
new file mode 100644
index 0000000..9c6df1b
--- /dev/null
+++ b/drivers/cpufreq/mediatek-cpufreq-hw.c
@@ -0,0 +1,340 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020 MediaTek Inc.
+ */
+
+#include <linux/bitfield.h>
+#include <linux/cpufreq.h>
+#include <linux/energy_model.h>
+#include <linux/init.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_platform.h>
+#include <linux/slab.h>
+
+#define LUT_MAX_ENTRIES 32U
+#define LUT_FREQ GENMASK(11, 0)
+#define LUT_ROW_SIZE 0x4
+#define CPUFREQ_HW_STATUS BIT(0)
+#define SVS_HW_STATUS BIT(1)
+#define POLL_USEC 1000
+#define TIMEOUT_USEC 300000
+
+enum {
+ REG_FREQ_LUT_TABLE,
+ REG_FREQ_ENABLE,
+ REG_FREQ_PERF_STATE,
+ REG_FREQ_HW_STATE,
+ REG_EM_POWER_TBL,
+ REG_FREQ_LATENCY,
+
+ REG_ARRAY_SIZE,
+};
+
+struct mtk_cpufreq_drv;
+
+struct mtk_cpufreq_drv {
+ const u16 *offsets;
+};
+
+struct mtk_cpufreq_data {
+ struct cpufreq_frequency_table *table;
+ void __iomem *reg_bases[REG_ARRAY_SIZE];
+ int nr_opp;
+};
+
+static const u16 cpufreq_mtk_offsets[REG_ARRAY_SIZE] = {
+ [REG_FREQ_LUT_TABLE] = 0x0,
+ [REG_FREQ_ENABLE] = 0x84,
+ [REG_FREQ_PERF_STATE] = 0x88,
+ [REG_FREQ_HW_STATE] = 0x8c,
+ [REG_EM_POWER_TBL] = 0x90,
+ [REG_FREQ_LATENCY] = 0x110,
+};
+
+static int __maybe_unused
+mtk_cpufreq_get_cpu_power(unsigned long *mW,
+ unsigned long *KHz, struct device *cpu_dev)
+{
+ struct mtk_cpufreq_data *data;
+ struct cpufreq_policy *policy;
+ int i;
+
+ policy = cpufreq_cpu_get_raw(cpu_dev->id);
+ if (!policy)
+ return 0;
+
+ data = policy->driver_data;
+
+ for (i = 0; i < data->nr_opp; i++) {
+ if (data->table[i].frequency < *KHz)
+ break;
+ }
+ i--;
+
+ *KHz = data->table[i].frequency;
+ *mW = readl_relaxed(data->reg_bases[REG_EM_POWER_TBL] +
+ i * LUT_ROW_SIZE) / 1000;
+
+ return 0;
+}
+
+static int mtk_cpufreq_hw_target_index(struct cpufreq_policy *policy,
+ unsigned int index)
+{
+ struct mtk_cpufreq_data *data = policy->driver_data;
+
+ writel_relaxed(index, data->reg_bases[REG_FREQ_PERF_STATE]);
+
+ return 0;
+}
+
+static unsigned int mtk_cpufreq_hw_get(unsigned int cpu)
+{
+ struct mtk_cpufreq_data *data;
+ struct cpufreq_policy *policy;
+ unsigned int index;
+
+ policy = cpufreq_cpu_get_raw(cpu);
+ if (!policy)
+ return 0;
+
+ data = policy->driver_data;
+
+ index = readl_relaxed(data->reg_bases[REG_FREQ_PERF_STATE]);
+ index = min(index, LUT_MAX_ENTRIES - 1);
+
+ return data->table[index].frequency;
+}
+
+static unsigned int mtk_cpufreq_hw_fast_switch(struct cpufreq_policy *policy,
+ unsigned int target_freq)
+{
+ struct mtk_cpufreq_data *data = policy->driver_data;
+ unsigned int index;
+
+ index = cpufreq_table_find_index_dl(policy, target_freq);
+
+ writel_relaxed(index, data->reg_bases[REG_FREQ_PERF_STATE]);
+
+ return policy->freq_table[index].frequency;
+}
+
+static int mtk_cpu_create_freq_table(struct platform_device *pdev,
+ struct mtk_cpufreq_data *data)
+{
+ struct device *dev = &pdev->dev;
+ void __iomem *base_table;
+ u32 temp, i, freq, prev_freq = 0;
+
+ data->table = devm_kcalloc(dev, LUT_MAX_ENTRIES + 1,
+ sizeof(*data->table), GFP_KERNEL);
+ if (!data->table)
+ return -ENOMEM;
+
+ base_table = data->reg_bases[REG_FREQ_LUT_TABLE];
+
+ for (i = 0; i < LUT_MAX_ENTRIES; i++) {
+ temp = readl_relaxed(base_table + (i * LUT_ROW_SIZE));
+ freq = FIELD_GET(LUT_FREQ, temp) * 1000;
+
+ if (freq == prev_freq)
+ break;
+
+ data->table[i].frequency = freq;
+
+ dev_dbg(dev, "index=%d freq=%d\n", i, data->table[i].frequency);
+
+ prev_freq = freq;
+ }
+
+ data->table[i].frequency = CPUFREQ_TABLE_END;
+ data->nr_opp = i;
+
+ return 0;
+}
+
+static int mtk_cpu_resources_init(struct platform_device *pdev,
+ struct cpufreq_policy *policy,
+ const u16 *offsets)
+{
+ struct mtk_cpufreq_data *data;
+ struct device *dev = &pdev->dev;
+ void __iomem *base;
+ int ret, i;
+ int index;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ index = of_perf_domain_get_sharing_cpumask(policy->cpu, "performance-domains",
+ "#performance-domain-cells",
+ policy->cpus);
+ if (index < 0)
+ return index;
+
+ base = devm_platform_ioremap_resource(pdev, index);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ for (i = REG_FREQ_LUT_TABLE; i < REG_ARRAY_SIZE; i++)
+ data->reg_bases[i] = base + offsets[i];
+
+ ret = mtk_cpu_create_freq_table(pdev, data);
+ if (ret) {
+ dev_info(dev, "Domain-%d failed to create freq table\n", index);
+ return ret;
+ }
+
+ policy->freq_table = data->table;
+ policy->driver_data = data;
+
+ return 0;
+}
+
+static int mtk_cpufreq_hw_cpu_init(struct cpufreq_policy *policy)
+{
+ struct platform_device *pdev = cpufreq_get_driver_data();
+ struct mtk_cpufreq_drv *drv = platform_get_drvdata(pdev);
+ int sig, pwr_hw = CPUFREQ_HW_STATUS | SVS_HW_STATUS;
+ struct mtk_cpufreq_data *data;
+ struct device *cpu_dev;
+ unsigned int latency;
+ int ret;
+
+ /* Get the bases of cpufreq for domains */
+ ret = mtk_cpu_resources_init(pdev, policy, drv->offsets);
+ if (ret) {
+ dev_info(&pdev->dev, "CPUFreq resource init failed\n");
+ return ret;
+ }
+
+ data = policy->driver_data;
+
+ latency = readl_relaxed(data->reg_bases[REG_FREQ_LATENCY]) * 1000;
+ if (!latency)
+ latency = CPUFREQ_ETERNAL;
+
+ /* us convert to ns */
+ policy->cpuinfo.transition_latency = latency;
+
+ policy->fast_switch_possible = true;
+
+ /* HW should be in enabled state to proceed now */
+ writel_relaxed(0x1, data->reg_bases[REG_FREQ_ENABLE]);
+ if (readl_poll_timeout(data->reg_bases[REG_FREQ_HW_STATE], sig,
+ (sig & pwr_hw) == pwr_hw, POLL_USEC,
+ TIMEOUT_USEC)) {
+ if (!(sig & CPUFREQ_HW_STATUS)) {
+ pr_info("cpufreq hardware of CPU%d is not enabled\n",
+ policy->cpu);
+ return -ENODEV;
+ }
+
+ pr_info("SVS of CPU%d is not enabled\n", policy->cpu);
+ }
+
+ cpu_dev = get_cpu_device(policy->cpu);
+ if (!cpu_dev) {
+ pr_info("failed to get cpu%d device\n", policy->cpu);
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+static int mtk_cpufreq_hw_cpu_exit(struct cpufreq_policy *policy)
+{
+ struct mtk_cpufreq_data *data = policy->driver_data;
+
+ /* HW should be in paused state now */
+ writel_relaxed(0x0, data->reg_bases[REG_FREQ_ENABLE]);
+
+ return 0;
+}
+
+static void mtk_cpufreq_register_em(struct cpufreq_policy *policy)
+{
+ struct em_data_callback em_cb = EM_DATA_CB(mtk_cpufreq_get_cpu_power);
+ struct mtk_cpufreq_data *data = policy->driver_data;
+
+ if (!data->nr_opp)
+ return;
+
+ em_dev_register_perf_domain(get_cpu_device(policy->cpu), data->nr_opp,
+ &em_cb, policy->cpus, true);
+}
+
+static struct cpufreq_driver cpufreq_mtk_hw_driver = {
+ .flags = CPUFREQ_NEED_INITIAL_FREQ_CHECK |
+ CPUFREQ_HAVE_GOVERNOR_PER_POLICY |
+ CPUFREQ_IS_COOLING_DEV,
+ .verify = cpufreq_generic_frequency_table_verify,
+ .target_index = mtk_cpufreq_hw_target_index,
+ .get = mtk_cpufreq_hw_get,
+ .init = mtk_cpufreq_hw_cpu_init,
+ .exit = mtk_cpufreq_hw_cpu_exit,
+ .register_em = mtk_cpufreq_register_em,
+ .fast_switch = mtk_cpufreq_hw_fast_switch,
+ .name = "mtk-cpufreq-hw",
+ .attr = cpufreq_generic_attr,
+};
+
+static int mtk_cpufreq_hw_driver_probe(struct platform_device *pdev)
+{
+ struct mtk_cpufreq_drv *drv;
+ const u16 *offsets;
+ int ret;
+
+ offsets = of_device_get_match_data(&pdev->dev);
+ if (!offsets)
+ return -EINVAL;
+
+ drv = kzalloc(sizeof(*drv), GFP_KERNEL);
+ if (!drv)
+ return -ENOMEM;
+
+ drv->offsets = offsets;
+
+ platform_set_drvdata(pdev, drv);
+
+ cpufreq_mtk_hw_driver.driver_data = pdev;
+
+ ret = cpufreq_register_driver(&cpufreq_mtk_hw_driver);
+ if (ret)
+ dev_err(&pdev->dev, "CPUFreq HW driver failed to register\n");
+
+ return ret;
+}
+
+static int mtk_cpufreq_hw_driver_remove(struct platform_device *pdev)
+{
+ struct mtk_cpufreq_drv *drv = platform_get_drvdata(pdev);
+
+ kfree(drv->offsets);
+ kfree(drv);
+
+ return cpufreq_unregister_driver(&cpufreq_mtk_hw_driver);
+}
+
+static const struct of_device_id mtk_cpufreq_hw_match[] = {
+ { .compatible = "mediatek,cpufreq-hw", .data = &cpufreq_mtk_offsets },
+ {}
+};
+
+static struct platform_driver mtk_cpufreq_hw_driver = {
+ .probe = mtk_cpufreq_hw_driver_probe,
+ .remove = mtk_cpufreq_hw_driver_remove,
+ .driver = {
+ .name = "mtk-cpufreq-hw",
+ .of_match_table = mtk_cpufreq_hw_match,
+ },
+};
+module_platform_driver(mtk_cpufreq_hw_driver);
+
+MODULE_AUTHOR("Hector Yuan <hector.yuan@xxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Mediatek cpufreq-hw driver");
+MODULE_LICENSE("GPL v2");
--
1.7.9.5
