--- /dev/null
+/*
+ * Copyright (C) 2007 PA Semi, Inc
+ *
+ * Authors: Egor Martovetsky <egor@pasemi.com>
+ * Olof Johansson <olof@lixom.net>
+ *
+ * Maintained by: Olof Johansson <olof@lixom.net>
+ *
+ * Based on arch/powerpc/platforms/cell/cbe_cpufreq.c:
+ * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/cpufreq.h>
+#include <linux/timer.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+
+#include <asm/hw_irq.h>
+#include <asm/io.h>
+#include <asm/prom.h>
+#include <asm/time.h>
+#include <asm/smp.h>
+
+#define SDCASR_REG 0x0100
+#define SDCASR_REG_STRIDE 0x1000
+#define SDCPWR_CFGA0_REG 0x0100
+#define SDCPWR_PWST0_REG 0x0000
+#define SDCPWR_GIZTIME_REG 0x0440
+
+/* SDCPWR_GIZTIME_REG fields */
+#define SDCPWR_GIZTIME_GR 0x80000000
+#define SDCPWR_GIZTIME_LONGLOCK 0x000000ff
+
+/* Offset of ASR registers from SDC base */
+#define SDCASR_OFFSET 0x120000
+
+static void __iomem *sdcpwr_mapbase;
+static void __iomem *sdcasr_mapbase;
+
+/* Current astate, is used when waking up from power savings on
+ * one core, in case the other core has switched states during
+ * the idle time.
+ */
+static int current_astate;
+
+/* We support 5(A0-A4) power states excluding turbo(A5-A6) modes */
+static struct cpufreq_frequency_table pas_freqs[] = {
+ {0, 0, 0},
+ {0, 1, 0},
+ {0, 2, 0},
+ {0, 3, 0},
+ {0, 4, 0},
+ {0, 0, CPUFREQ_TABLE_END},
+};
+
+/*
+ * hardware specific functions
+ */
+
+static int get_astate_freq(int astate)
+{
+ u32 ret;
+ ret = in_le32(sdcpwr_mapbase + SDCPWR_CFGA0_REG + (astate * 0x10));
+
+ return ret & 0x3f;
+}
+
+static int get_cur_astate(int cpu)
+{
+ u32 ret;
+
+ ret = in_le32(sdcpwr_mapbase + SDCPWR_PWST0_REG);
+ ret = (ret >> (cpu * 4)) & 0x7;
+
+ return ret;
+}
+
+static int get_gizmo_latency(void)
+{
+ u32 giztime, ret;
+
+ giztime = in_le32(sdcpwr_mapbase + SDCPWR_GIZTIME_REG);
+
+ /* just provide the upper bound */
+ if (giztime & SDCPWR_GIZTIME_GR)
+ ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 128000;
+ else
+ ret = (giztime & SDCPWR_GIZTIME_LONGLOCK) * 1000;
+
+ return ret;
+}
+
+static void set_astate(int cpu, unsigned int astate)
+{
+ unsigned long flags;
+
+ /* Return if called before init has run */
+ if (unlikely(!sdcasr_mapbase))
+ return;
+
+ local_irq_save(flags);
+
+ out_le32(sdcasr_mapbase + SDCASR_REG + SDCASR_REG_STRIDE*cpu, astate);
+
+ local_irq_restore(flags);
+}
+
+int check_astate(void)
+{
+ return get_cur_astate(hard_smp_processor_id());
+}
+
+void restore_astate(int cpu)
+{
+ set_astate(cpu, current_astate);
+}
+
+/*
+ * cpufreq functions
+ */
+
+static int pas_cpufreq_cpu_init(struct cpufreq_policy *policy)
+{
+ struct cpufreq_frequency_table *pos;
+ const u32 *max_freqp;
+ u32 max_freq;
+ int cur_astate;
+ struct resource res;
+ struct device_node *cpu, *dn;
+ int err = -ENODEV;
+
+ cpu = of_get_cpu_node(policy->cpu, NULL);
+
+ if (!cpu)
+ goto out;
+
+ dn = of_find_compatible_node(NULL, NULL, "1682m-sdc");
+ if (!dn)
+ dn = of_find_compatible_node(NULL, NULL,
+ "pasemi,pwrficient-sdc");
+ if (!dn)
+ goto out;
+ err = of_address_to_resource(dn, 0, &res);
+ of_node_put(dn);
+ if (err)
+ goto out;
+ sdcasr_mapbase = ioremap(res.start + SDCASR_OFFSET, 0x2000);
+ if (!sdcasr_mapbase) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ dn = of_find_compatible_node(NULL, NULL, "1682m-gizmo");
+ if (!dn)
+ dn = of_find_compatible_node(NULL, NULL,
+ "pasemi,pwrficient-gizmo");
+ if (!dn) {
+ err = -ENODEV;
+ goto out_unmap_sdcasr;
+ }
+ err = of_address_to_resource(dn, 0, &res);
+ of_node_put(dn);
+ if (err)
+ goto out_unmap_sdcasr;
+ sdcpwr_mapbase = ioremap(res.start, 0x1000);
+ if (!sdcpwr_mapbase) {
+ err = -EINVAL;
+ goto out_unmap_sdcasr;
+ }
+
+ pr_debug("init cpufreq on CPU %d\n", policy->cpu);
+
+ max_freqp = of_get_property(cpu, "clock-frequency", NULL);
+ if (!max_freqp) {
+ err = -EINVAL;
+ goto out_unmap_sdcpwr;
+ }
+
+ /* we need the freq in kHz */
+ max_freq = *max_freqp / 1000;
+
+ pr_debug("max clock-frequency is at %u kHz\n", max_freq);
+ pr_debug("initializing frequency table\n");
+
+ /* initialize frequency table */
+ cpufreq_for_each_entry(pos, pas_freqs) {
+ pos->frequency = get_astate_freq(pos->driver_data) * 100000;
+ pr_debug("%d: %d\n", (int)(pos - pas_freqs), pos->frequency);
+ }
+
+ cur_astate = get_cur_astate(policy->cpu);
+ pr_debug("current astate is at %d\n",cur_astate);
+
+ policy->cur = pas_freqs[cur_astate].frequency;
+ ppc_proc_freq = policy->cur * 1000ul;
+
+ return cpufreq_generic_init(policy, pas_freqs, get_gizmo_latency());
+
+out_unmap_sdcpwr:
+ iounmap(sdcpwr_mapbase);
+
+out_unmap_sdcasr:
+ iounmap(sdcasr_mapbase);
+out:
+ return err;
+}
+
+static int pas_cpufreq_cpu_exit(struct cpufreq_policy *policy)
+{
+ /*
+ * We don't support CPU hotplug. Don't unmap after the system
+ * has already made it to a running state.
+ */
+ if (system_state != SYSTEM_BOOTING)
+ return 0;
+
+ if (sdcasr_mapbase)
+ iounmap(sdcasr_mapbase);
+ if (sdcpwr_mapbase)
+ iounmap(sdcpwr_mapbase);
+
+ return 0;
+}
+
+static int pas_cpufreq_target(struct cpufreq_policy *policy,
+ unsigned int pas_astate_new)
+{
+ int i;
+
+ pr_debug("setting frequency for cpu %d to %d kHz, 1/%d of max frequency\n",
+ policy->cpu,
+ pas_freqs[pas_astate_new].frequency,
+ pas_freqs[pas_astate_new].driver_data);
+
+ current_astate = pas_astate_new;
+
+ for_each_online_cpu(i)
+ set_astate(i, pas_astate_new);
+
+ ppc_proc_freq = pas_freqs[pas_astate_new].frequency * 1000ul;
+ return 0;
+}
+
+static struct cpufreq_driver pas_cpufreq_driver = {
+ .name = "pas-cpufreq",
+ .flags = CPUFREQ_CONST_LOOPS,
+ .init = pas_cpufreq_cpu_init,
+ .exit = pas_cpufreq_cpu_exit,
+ .verify = cpufreq_generic_frequency_table_verify,
+ .target_index = pas_cpufreq_target,
+ .attr = cpufreq_generic_attr,
+};
+
+/*
+ * module init and destoy
+ */
+
+static int __init pas_cpufreq_init(void)
+{
+ if (!of_machine_is_compatible("PA6T-1682M") &&
+ !of_machine_is_compatible("pasemi,pwrficient"))
+ return -ENODEV;
+
+ return cpufreq_register_driver(&pas_cpufreq_driver);
+}
+
+static void __exit pas_cpufreq_exit(void)
+{
+ cpufreq_unregister_driver(&pas_cpufreq_driver);
+}
+
+module_init(pas_cpufreq_init);
+module_exit(pas_cpufreq_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Egor Martovetsky <egor@pasemi.com>, Olof Johansson <olof@lixom.net>");
Code Review / kvmfornfv.git / blobdiff