[PATCH v6 14/15] cpufreq: Add module to register cpufreq on Krait CPUs

From: Sricharan R
Date: Mon Feb 05 2018 - 23:11:52 EST


From: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>

Register a cpufreq-generic device whenever we detect that a
"qcom,krait" compatible CPU is present in DT.

Cc: <devicetree@xxxxxxxxxxxxxxx>
[Sricharan: updated to use dev_pm_opp_set_prop_name, NVMEM apis,
new binding]
Signed-off-by: Sricharan R <sricharan@xxxxxxxxxxxxxx>
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxxxxxx>
---
drivers/cpufreq/Kconfig.arm | 10 +++
drivers/cpufreq/Makefile | 1 +
drivers/cpufreq/cpufreq-dt-platdev.c | 5 ++
drivers/cpufreq/qcom-cpufreq.c | 161 +++++++++++++++++++++++++++++++++++
4 files changed, 177 insertions(+)
create mode 100644 drivers/cpufreq/qcom-cpufreq.c

diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index bdce448..076d039 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -100,6 +100,16 @@ config ARM_OMAP2PLUS_CPUFREQ
depends on ARCH_OMAP2PLUS
default ARCH_OMAP2PLUS

+config ARM_QCOM_CPUFREQ
+ bool "CPUfreq driver for the QCOM SoCs with KRAIT processors"
+ depends on ARCH_QCOM
+ select PM_OPP
+ help
+ This enables the CPUFreq driver for Qualcomm SoCs with
+ KRAIT processors.
+
+ If in doubt, say N.
+
config ARM_S3C_CPUFREQ
bool
help
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 812f9e0..1496464 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -62,6 +62,7 @@ obj-$(CONFIG_ARM_MEDIATEK_CPUFREQ) += mediatek-cpufreq.o
obj-$(CONFIG_ARM_OMAP2PLUS_CPUFREQ) += omap-cpufreq.o
obj-$(CONFIG_ARM_PXA2xx_CPUFREQ) += pxa2xx-cpufreq.o
obj-$(CONFIG_PXA3xx) += pxa3xx-cpufreq.o
+obj-$(CONFIG_ARM_QCOM_CPUFREQ) += qcom-cpufreq.o
obj-$(CONFIG_ARM_S3C24XX_CPUFREQ) += s3c24xx-cpufreq.o
obj-$(CONFIG_ARM_S3C24XX_CPUFREQ_DEBUGFS) += s3c24xx-cpufreq-debugfs.o
obj-$(CONFIG_ARM_S3C2410_CPUFREQ) += s3c2410-cpufreq.o
diff --git a/drivers/cpufreq/cpufreq-dt-platdev.c b/drivers/cpufreq/cpufreq-dt-platdev.c
index ecc56e2..8a55a85 100644
--- a/drivers/cpufreq/cpufreq-dt-platdev.c
+++ b/drivers/cpufreq/cpufreq-dt-platdev.c
@@ -119,6 +119,11 @@
{ .compatible = "ti,am43", },
{ .compatible = "ti,dra7", },

+ { .compatible = "qcom,ipq8064", },
+ { .compatible = "qcom,apq8064", },
+ { .compatible = "qcom,msm8974", },
+ { .compatible = "qcom,msm8960", },
+
{ }
};

diff --git a/drivers/cpufreq/qcom-cpufreq.c b/drivers/cpufreq/qcom-cpufreq.c
new file mode 100644
index 0000000..5b988d4
--- /dev/null
+++ b/drivers/cpufreq/qcom-cpufreq.c
@@ -0,0 +1,161 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (c) 2018, The Linux Foundation. All rights reserved.
+
+#include <linux/cpu.h>
+#include <linux/err.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/pm_opp.h>
+#include <linux/slab.h>
+#include "cpufreq-dt.h"
+#include <linux/nvmem-consumer.h>
+
+static void __init get_krait_bin_format_a(int *speed, int *pvs, int *pvs_ver,
+ struct nvmem_cell *pvs_nvmem, u8 *buf)
+{
+ u32 pte_efuse;
+
+ pte_efuse = *((u32 *)buf);
+
+ *speed = pte_efuse & 0xf;
+ if (*speed == 0xf)
+ *speed = (pte_efuse >> 4) & 0xf;
+
+ if (*speed == 0xf) {
+ *speed = 0;
+ pr_warn("Speed bin: Defaulting to %d\n", *speed);
+ } else {
+ pr_info("Speed bin: %d\n", *speed);
+ }
+
+ *pvs = (pte_efuse >> 10) & 0x7;
+ if (*pvs == 0x7)
+ *pvs = (pte_efuse >> 13) & 0x7;
+
+ if (*pvs == 0x7) {
+ *pvs = 0;
+ pr_warn("PVS bin: Defaulting to %d\n", *pvs);
+ } else {
+ pr_info("PVS bin: %d\n", *pvs);
+ }
+
+ kfree(buf);
+}
+
+static void __init get_krait_bin_format_b(int *speed, int *pvs, int *pvs_ver,
+ struct nvmem_cell *pvs_nvmem, u8 *buf)
+{
+ u32 pte_efuse, redundant_sel;
+
+ pte_efuse = *((u32 *)buf);
+ redundant_sel = (pte_efuse >> 24) & 0x7;
+ *speed = pte_efuse & 0x7;
+
+ /* 4 bits of PVS are in efuse register bits 31, 8-6. */
+ *pvs = ((pte_efuse >> 28) & 0x8) | ((pte_efuse >> 6) & 0x7);
+ *pvs_ver = (pte_efuse >> 4) & 0x3;
+
+ switch (redundant_sel) {
+ case 1:
+ *speed = (pte_efuse >> 27) & 0xf;
+ break;
+ case 2:
+ *pvs = (pte_efuse >> 27) & 0xf;
+ break;
+ }
+
+ /* Check SPEED_BIN_BLOW_STATUS */
+ if (pte_efuse & BIT(3)) {
+ pr_info("Speed bin: %d\n", *speed);
+ } else {
+ pr_warn("Speed bin not set. Defaulting to 0!\n");
+ *speed = 0;
+ }
+
+ /* Check PVS_BLOW_STATUS */
+ pte_efuse = *(((u32 *)buf) + 4);
+ if (pte_efuse) {
+ pr_info("PVS bin: %d\n", *pvs);
+ } else {
+ pr_warn("PVS bin not set. Defaulting to 0!\n");
+ *pvs = 0;
+ }
+
+ pr_info("PVS version: %d\n", *pvs_ver);
+ kfree(buf);
+}
+
+static int __init qcom_cpufreq_populate_opps(struct nvmem_cell *pvs_nvmem)
+{
+ int speed = 0, pvs = 0, pvs_ver = 0, cpu;
+ struct device *dev;
+ u8 *buf;
+ size_t len;
+ char pvs_name[] = "speedXX-pvsXX-vXX";
+
+ buf = nvmem_cell_read(pvs_nvmem, &len);
+ if (len == 4)
+ get_krait_bin_format_a(&speed, &pvs, &pvs_ver, pvs_nvmem, buf);
+ else if (len == 8)
+ get_krait_bin_format_b(&speed, &pvs, &pvs_ver, pvs_nvmem, buf);
+ else
+ pr_warn("Unable to read nvmem data. Defaulting to 0!\n");
+
+ snprintf(pvs_name, sizeof(pvs_name), "speed%d-pvs%d-v%d",
+ speed, pvs, pvs_ver);
+
+ for (cpu = 0; cpu < num_possible_cpus(); cpu++) {
+ dev = get_cpu_device(cpu);
+ if (!dev)
+ return -ENODEV;
+
+ if (IS_ERR(dev_pm_opp_set_prop_name(dev, pvs_name)))
+ pr_warn("failed to add OPP name %s\n", pvs_name);
+ }
+
+ return 0;
+}
+
+static int __init qcom_cpufreq_driver_init(void)
+{
+ struct device *cpu_dev;
+ struct device_node *np;
+ struct nvmem_cell *pvs_nvmem;
+ int ret;
+
+ cpu_dev = get_cpu_device(0);
+ if (!cpu_dev)
+ return -ENODEV;
+
+ np = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
+ if (!np)
+ return -ENOENT;
+
+ if (!of_device_is_compatible(np, "operating-points-v2-krait-cpu")) {
+ of_node_put(np);
+ return -ENODEV;
+ }
+
+ pvs_nvmem = of_nvmem_cell_get(np, NULL);
+ if (IS_ERR(pvs_nvmem)) {
+ dev_err(cpu_dev, "Could not get nvmem cell\n");
+ return PTR_ERR(pvs_nvmem);
+ }
+
+ of_node_put(np);
+
+ ret = qcom_cpufreq_populate_opps(pvs_nvmem);
+ if (ret)
+ return ret;
+
+ return PTR_ERR(platform_device_register_simple("cpufreq-dt",
+ -1, NULL, 0));
+}
+module_init(qcom_cpufreq_driver_init);
+
+MODULE_DESCRIPTION("Qualcomm CPUfreq driver");
+MODULE_LICENSE("GPL v2");
--
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