cpufreq: ARM big LITTLE: Add Vexpress glue driver

Vexpress depends on motherboard firmware + spc for getting opp table. This patch
adds Vexpress glue driver for ARM big LITTLE parent driver.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>

diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 9c6a69112e8752e19196263678f8f4b45b8e6b27..203e8959bde490d57eddce72fb5b41b14c441f5d 100644 (file)
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -15,6 +15,14 @@ config ARM_DT_BL_CPUFREQ
          This enables probing via DT for Generic CPUfreq driver for ARM
          big.LITTLE platform. This gets frequency tables from DT.
 
+config ARM_VEXPRESS_BL_CPUFREQ
+       tristate "ARM Vexpress big LITTLE CPUfreq driver"
+       select ARM_BIG_LITTLE_CPUFREQ
+       depends on ARM_SPC
+       help
+         This enables the CPUfreq driver for ARM Vexpress big.LITTLE platform.
+         If in doubt, say N.
+
 config ARM_EXYNOS_CPUFREQ
        bool "SAMSUNG EXYNOS SoCs"
        depends on ARCH_EXYNOS

diff --git a/drivers/cpufreq/Makefile b/drivers/cpufreq/Makefile
index 315b9231feb17f00d52fd4374f47c3bd9b6d57c4..1db9b4929cfa7bafe0040bfebe6812676881f5a5 100644 (file)
--- a/drivers/cpufreq/Makefile
+++ b/drivers/cpufreq/Makefile
@@ -48,6 +48,7 @@ obj-$(CONFIG_X86_AMD_FREQ_SENSITIVITY)        += amd_freq_sensitivity.o
 obj-$(CONFIG_ARM_BIG_LITTLE_CPUFREQ)   += arm_big_little.o
 # big LITTLE per platform glues. Keep DT_BL_CPUFREQ as the last entry in all big
 # LITTLE drivers, so that it is probed last.
+obj-$(CONFIG_ARM_VEXPRESS_BL_CPUFREQ)  += vexpress_big_little.o
 obj-$(CONFIG_ARM_DT_BL_CPUFREQ)                += arm_big_little_dt.o
 
 obj-$(CONFIG_ARCH_DAVINCI_DA850)       += davinci-cpufreq.o

diff --git a/drivers/cpufreq/vexpress_big_little.c b/drivers/cpufreq/vexpress_big_little.c
new file mode 100644 (file)
index 0000000..aac2462
--- /dev/null
+++ b/drivers/cpufreq/vexpress_big_little.c
@@ -0,0 +1,85 @@
+/*
+ * Vexpress big.LITTLE CPUFreq Interface driver
+ *
+ * It provides necessary ops to arm_big_little cpufreq driver and gets
+ * Frequency information from Device Tree. Freq table in DT must be in KHz.
+ *
+ * Copyright (C) 2013 Linaro.
+ * Viresh Kumar <viresh.kumar@linaro.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/cpufreq.h>
+#include <linux/export.h>
+#include <linux/opp.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/vexpress.h>
+#include "arm_big_little.h"
+
+static int vexpress_init_opp_table(struct device *cpu_dev)
+{
+       int i = -1, count, cluster = cpu_to_cluster(cpu_dev->id);
+       unsigned int *table = vexpress_spc_get_freq_table(cluster, &count);
+       int ret;
+
+       if (!table || !count) {
+               pr_err("SPC controller returned invalid freq table");
+               return -EINVAL;
+       }
+
+       while (++i < count) {
+               /* FIXME: Voltage value */
+               ret = opp_add(cpu_dev, table[i] * 1000, 900000);
+               if (ret) {
+                       dev_warn(cpu_dev, "%s: Failed to add OPP %d, err: %d\n",
+                                __func__, table[i] * 1000, ret);
+                       return ret;
+               }
+       }
+
+       return 0;
+}
+
+static int vexpress_get_transition_latency(struct device *cpu_dev)
+{
+       /* 1 ms */
+       return 1000000;
+}
+
+static struct cpufreq_arm_bL_ops vexpress_bL_ops = {
+       .name   = "vexpress-bL",
+       .get_transition_latency = vexpress_get_transition_latency,
+       .init_opp_table = vexpress_init_opp_table,
+};
+
+static int vexpress_bL_init(void)
+{
+       if (!vexpress_spc_check_loaded()) {
+               pr_info("%s: No SPC found\n", __func__);
+               return -ENOENT;
+       }
+
+       return bL_cpufreq_register(&vexpress_bL_ops);
+}
+module_init(vexpress_bL_init);
+
+static void vexpress_bL_exit(void)
+{
+       return bL_cpufreq_unregister(&vexpress_bL_ops);
+}
+module_exit(vexpress_bL_exit);
+
+MODULE_AUTHOR("Viresh Kumar <viresh.kumar@linaro.org>");
+MODULE_DESCRIPTION("ARM Vexpress big LITTLE cpufreq driver");
+MODULE_LICENSE("GPL");