[PATCH v3 12/13] cpufreq: Add module to register cpufreq on Krait CPUs

Stephen Boyd
2015-03-21T06:46:23Z

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

Cc: <devicetree@vger.kernel.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
---
.../devicetree/bindings/arm/msm/qcom,pvs.txt | 38 ++++
drivers/cpufreq/Kconfig.arm | 9 +
drivers/cpufreq/Makefile | 1 +
drivers/cpufreq/qcom-cpufreq.c | 204 +++++++++++++++++++++
4 files changed, 252 insertions(+)
create mode 100644 Documentation/devicetree/bindings/arm/msm/qcom,pvs.txt
create mode 100644 drivers/cpufreq/qcom-cpufreq.c

diff --git a/Documentation/devicetree/bindings/arm/msm/qcom,pvs.txt b/Documentation/devicetree/bindings/arm/msm/qcom,pvs.txt
new file mode 100644
index 000000000000..e7cb10426a3b
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/msm/qcom,pvs.txt
@@ -0,0 +1,38 @@
+Qualcomm Process Voltage Scaling Tables
+
+The node name is required to be "qcom,pvs". There shall only be one
+such node present in the root of the tree.
+
+PROPERTIES
+
+- qcom,pvs-format-a or qcom,pvs-format-b:
+ Usage: required
+ Value type: <empty>
+ Definition: Indicates the format of qcom,speedX-pvsY-bin-vZ properties.
+ If qcom,pvs-format-a is used the table is two columns
+ (frequency and voltage in that order). If qcom,pvs-format-b is used the table is three columns (frequency, voltage,
+ and current in that order).
+
+- qcom,speedX-pvsY-bin-vZ:
+ Usage: required
+ Value type: <prop-encoded-array>
+ Definition: The PVS table corresponding to the speed bin X, pvs bin Y,
+ and version Z.
+Example:
+
+ qcom,pvs {
+ qcom,pvs-format-a;
+ qcom,speed0-pvs0-bin-v0 =
+ < 384000000 950000 >,
+ < 486000000 975000 >,
+ < 594000000 1000000 >,
+ < 702000000 1025000 >,
+ < 810000000 1075000 >,
+ < 918000000 1100000 >,
+ < 1026000000 1125000 >,
+ < 1134000000 1175000 >,
+ < 1242000000 1200000 >,
+ < 1350000000 1225000 >,
+ < 1458000000 1237500 >,
+ < 1512000000 1250000 >;
+ };
diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 1b06fc4640e2..3829d5521dfc 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -137,6 +137,15 @@ config ARM_OMAP2PLUS_CPUFREQ
depends on ARCH_OMAP2PLUS
default ARCH_OMAP2PLUS

+config ARM_QCOM_CPUFREQ
+ tristate "Qualcomm based"
+ depends on ARCH_QCOM
+ select PM_OPP
+ help
+ This adds the CPUFreq driver for Qualcomm SoC based boards.
+
+ If in doubt, say N.
+
config ARM_S3C_CPUFREQ
bool
help
diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 82a1821471fd..be95ed8d6873 100644
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -65,6 +65,7 @@ obj-$(CONFIG_ARM_KIRKWOOD_CPUFREQ) += kirkwood-cpufreq.o
obj-$(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/qcom-cpufreq.c b/drivers/cpufreq/qcom-cpufreq.c
new file mode 100644
index 000000000000..c9f86a062cdd
--- /dev/null
+++ b/drivers/cpufreq/qcom-cpufreq.c
@@ -0,0 +1,204 @@
+/* Copyright (c) 2014, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#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 <linux/cpufreq-dt.h>
+
+static void __init get_krait_bin_format_a(int *speed, int *pvs, int *pvs_ver)
+{
+ void __iomem *base;
+ u32 pte_efuse;
+
+ *speed = *pvs = *pvs_ver = 0;
+
+ base = ioremap(0x007000c0, 4);
+ if (!base) {
+ pr_warn("Unable to read efuse data. Defaulting to 0!\n");
+ return;
+ }
+
+ pte_efuse = readl_relaxed(base);
+ iounmap(base);
+
+ *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);
+ }
+}
+
+static void __init get_krait_bin_format_b(int *speed, int *pvs, int *pvs_ver)
+{
+ u32 pte_efuse, redundant_sel;
+ void __iomem *base;
+
+ *speed = 0;
+ *pvs = 0;
+ *pvs_ver = 0;
+
+ base = ioremap(0xfc4b80b0, 8);
+ if (!base) {
+ pr_warn("Unable to read efuse data. Defaulting to 0!\n");
+ return;
+ }
+
+ pte_efuse = readl_relaxed(base);
+ 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 = readl_relaxed(base + 0x4) & BIT(21);
+ 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);
+ iounmap(base);
+}
+
+static int __init qcom_cpufreq_populate_opps(void)
+{
+ int len, rows, cols, i, k, speed, pvs, pvs_ver;
+ char table_name[] = "qcom,speedXX-pvsXX-bin-vXX";
+ struct device_node *np;
+ struct device *dev;
+ int cpu = 0;
+
+ np = of_find_node_by_name(NULL, "qcom,pvs");
+ if (!np)
+ return -ENODEV;
+
+ if (of_property_read_bool(np, "qcom,pvs-format-a")) {
+ get_krait_bin_format_a(&speed, &pvs, &pvs_ver);
+ cols = 2;
+ } else if (of_property_read_bool(np, "qcom,pvs-format-b")) {
+ get_krait_bin_format_b(&speed, &pvs, &pvs_ver);
+ cols = 3;
+ } else {
+ return -ENODEV;
+ }
+
+ snprintf(table_name, sizeof(table_name),
+ "qcom,speed%d-pvs%d-bin-v%d", speed, pvs, pvs_ver);
+
+ if (!of_find_property(np, table_name, &len))
+ return -EINVAL;
+
+ len /= sizeof(u32);
+ if (len % cols || len == 0)
+ return -EINVAL;
+
+ rows = len / cols;
+
+ for (i = 0, k = 0; i < rows; i++) {
+ u32 freq, volt;
+
+ of_property_read_u32_index(np, table_name, k++, &freq);
+ of_property_read_u32_index(np, table_name, k++, &volt);
+ while (k % cols)
+ k++; /* Skip uA entries if present */
+ for (cpu = 0; cpu < num_possible_cpus(); cpu++) {
+ dev = get_cpu_device(cpu);
+ if (!dev)
+ return -ENODEV;
+ if (dev_pm_opp_add(dev, freq, volt))
+ pr_warn("failed to add OPP %u\n", freq);
+ }
+ }
+
+ return 0;
+}
+
+static int __init qcom_cpufreq_driver_init(void)
+{
+ struct cpufreq_dt_platform_data pdata = { .independent_clocks = true };
+ struct platform_device_info devinfo = {
+ .name = "cpufreq-dt",
+ .data = &pdata,
+ .size_data = sizeof(pdata),
+ };
+ struct device *cpu_dev;
+ struct device_node *np;
+ int ret;
+
+ cpu_dev = get_cpu_device(0);
+ if (!cpu_dev)
+ return -ENODEV;
+
+ np = of_node_get(cpu_dev->of_node);
+ if (!np)
+ return -ENOENT;
+
+ if (!of_device_is_compatible(np, "qcom,krait")) {
+ of_node_put(np);
+ return -ENODEV;
+ }
+ of_node_put(np);
+
+ ret = qcom_cpufreq_populate_opps();
+ if (ret)
+ return ret;
+
+ return PTR_ERR_OR_ZERO(platform_device_register_full(&devinfo));
+}
+module_init(qcom_cpufreq_driver_init);
+
+MODULE_DESCRIPTION("Qualcomm CPUfreq driver");
+MODULE_LICENSE("GPL v2");