--- /dev/null
+PPC4xx Clock Power Management (CPM) node
+
+Required properties:
+ - compatible : compatible list, currently only "ibm,cpm"
+ - dcr-access-method : "native"
+ - dcr-reg : < DCR register range >
+
+Optional properties:
+ - er-offset : All 4xx SoCs with a CPM controller have
+ one of two different order for the CPM
+ registers. Some have the CPM registers
+ in the following order (ER,FR,SR). The
+ others have them in the following order
+ (SR,ER,FR). For the second case set
+ er-offset = <1>.
+ - unused-units : specifier consist of one cell. For each
+ bit in the cell, the corresponding bit
+ in CPM will be set to turn off unused
+ devices.
+ - idle-doze : specifier consist of one cell. For each
+ bit in the cell, the corresponding bit
+ in CPM will be set to turn off unused
+ devices. This is usually just CPM[CPU].
+ - standby : specifier consist of one cell. For each
+ bit in the cell, the corresponding bit
+ in CPM will be set on standby and
+ restored on resume.
+ - suspend : specifier consist of one cell. For each
+ bit in the cell, the corresponding bit
+ in CPM will be set on suspend (mem) and
+ restored on resume. Note, for standby
+ and suspend the corresponding bits can
+ be different or the same. Usually for
+ standby only class 2 and 3 units are set.
+ However, the interface does not care.
+ If they are the same, the additional
+ power saving will be seeing if support
+ is available to put the DDR in self
+ refresh mode and any additional power
+ saving techniques for the specific SoC.
+
+Example:
+ CPM0: cpm {
+ compatible = "ibm,cpm";
+ dcr-access-method = "native";
+ dcr-reg = <0x160 0x003>;
+ er-offset = <0>;
+ unused-units = <0x00000100>;
+ idle-doze = <0x02000000>;
+ standby = <0xfeff0000>;
+ suspend = <0xfeff791d>;
+};
--- /dev/null
+/*
+ * PowerPC 4xx Clock and Power Management
+ *
+ * Copyright (C) 2010, Applied Micro Circuits Corporation
+ * Victor Gallardo (vgallardo@apm.com)
+ *
+ * Based on arch/powerpc/platforms/44x/idle.c:
+ * Jerone Young <jyoung5@us.ibm.com>
+ * Copyright 2008 IBM Corp.
+ *
+ * Based on arch/powerpc/sysdev/fsl_pmc.c:
+ * Anton Vorontsov <avorontsov@ru.mvista.com>
+ * Copyright 2009 MontaVista Software, Inc.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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 of
+ * the License, 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., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/of_platform.h>
+#include <linux/sysfs.h>
+#include <linux/cpu.h>
+#include <linux/suspend.h>
+#include <asm/dcr.h>
+#include <asm/dcr-native.h>
+#include <asm/machdep.h>
+
+#define CPM_ER 0
+#define CPM_FR 1
+#define CPM_SR 2
+
+#define CPM_IDLE_WAIT 0
+#define CPM_IDLE_DOZE 1
+
+struct cpm {
+ dcr_host_t dcr_host;
+ unsigned int dcr_offset[3];
+ unsigned int powersave_off;
+ unsigned int unused;
+ unsigned int idle_doze;
+ unsigned int standby;
+ unsigned int suspend;
+};
+
+static struct cpm cpm;
+
+struct cpm_idle_mode {
+ unsigned int enabled;
+ const char *name;
+};
+
+static struct cpm_idle_mode idle_mode[] = {
+ [CPM_IDLE_WAIT] = { 1, "wait" }, /* default */
+ [CPM_IDLE_DOZE] = { 0, "doze" },
+};
+
+static unsigned int cpm_set(unsigned int cpm_reg, unsigned int mask)
+{
+ unsigned int value;
+
+ /* CPM controller supports 3 different types of sleep interface
+ * known as class 1, 2 and 3. For class 1 units, they are
+ * unconditionally put to sleep when the corresponding CPM bit is
+ * set. For class 2 and 3 units this is not case; if they can be
+ * put to to sleep, they will. Here we do not verify, we just
+ * set them and expect them to eventually go off when they can.
+ */
+ value = dcr_read(cpm.dcr_host, cpm.dcr_offset[cpm_reg]);
+ dcr_write(cpm.dcr_host, cpm.dcr_offset[cpm_reg], value | mask);
+
+ /* return old state, to restore later if needed */
+ return value;
+}
+
+static void cpm_idle_wait(void)
+{
+ unsigned long msr_save;
+
+ /* save off initial state */
+ msr_save = mfmsr();
+ /* sync required when CPM0_ER[CPU] is set */
+ mb();
+ /* set wait state MSR */
+ mtmsr(msr_save|MSR_WE|MSR_EE|MSR_CE|MSR_DE);
+ isync();
+ /* return to initial state */
+ mtmsr(msr_save);
+ isync();
+}
+
+static void cpm_idle_sleep(unsigned int mask)
+{
+ unsigned int er_save;
+
+ /* update CPM_ER state */
+ er_save = cpm_set(CPM_ER, mask);
+
+ /* go to wait state so that CPM0_ER[CPU] can take effect */
+ cpm_idle_wait();
+
+ /* restore CPM_ER state */
+ dcr_write(cpm.dcr_host, cpm.dcr_offset[CPM_ER], er_save);
+}
+
+static void cpm_idle_doze(void)
+{
+ cpm_idle_sleep(cpm.idle_doze);
+}
+
+static void cpm_idle_config(int mode)
+{
+ int i;
+
+ if (idle_mode[mode].enabled)
+ return;
+
+ for (i = 0; i < ARRAY_SIZE(idle_mode); i++)
+ idle_mode[i].enabled = 0;
+
+ idle_mode[mode].enabled = 1;
+}
+
+static ssize_t cpm_idle_show(struct kobject *kobj,
+ struct kobj_attribute *attr, char *buf)
+{
+ char *s = buf;
+ int i;
+
+ for (i = 0; i < ARRAY_SIZE(idle_mode); i++) {
+ if (idle_mode[i].enabled)
+ s += sprintf(s, "[%s] ", idle_mode[i].name);
+ else
+ s += sprintf(s, "%s ", idle_mode[i].name);
+ }
+
+ *(s-1) = '\n'; /* convert the last space to a newline */
+
+ return s - buf;
+}
+
+static ssize_t cpm_idle_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *buf, size_t n)
+{
+ int i;
+ char *p;
+ int len;
+
+ p = memchr(buf, '\n', n);
+ len = p ? p - buf : n;
+
+ for (i = 0; i < ARRAY_SIZE(idle_mode); i++) {
+ if (strncmp(buf, idle_mode[i].name, len) == 0) {
+ cpm_idle_config(i);
+ return n;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static struct kobj_attribute cpm_idle_attr =
+ __ATTR(idle, 0644, cpm_idle_show, cpm_idle_store);
+
+static void cpm_idle_config_sysfs(void)
+{
+ struct sys_device *sys_dev;
+ unsigned long ret;
+
+ sys_dev = get_cpu_sysdev(0);
+
+ ret = sysfs_create_file(&sys_dev->kobj,
+ &cpm_idle_attr.attr);
+ if (ret)
+ printk(KERN_WARNING
+ "cpm: failed to create idle sysfs entry\n");
+}
+
+static void cpm_idle(void)
+{
+ if (idle_mode[CPM_IDLE_DOZE].enabled)
+ cpm_idle_doze();
+ else
+ cpm_idle_wait();
+}
+
+static int cpm_suspend_valid(suspend_state_t state)
+{
+ switch (state) {
+ case PM_SUSPEND_STANDBY:
+ return !!cpm.standby;
+ case PM_SUSPEND_MEM:
+ return !!cpm.suspend;
+ default:
+ return 0;
+ }
+}
+
+static void cpm_suspend_standby(unsigned int mask)
+{
+ unsigned long tcr_save;
+
+ /* disable decrement interrupt */
+ tcr_save = mfspr(SPRN_TCR);
+ mtspr(SPRN_TCR, tcr_save & ~TCR_DIE);
+
+ /* go to sleep state */
+ cpm_idle_sleep(mask);
+
+ /* restore decrement interrupt */
+ mtspr(SPRN_TCR, tcr_save);
+}
+
+static int cpm_suspend_enter(suspend_state_t state)
+{
+ switch (state) {
+ case PM_SUSPEND_STANDBY:
+ cpm_suspend_standby(cpm.standby);
+ break;
+ case PM_SUSPEND_MEM:
+ cpm_suspend_standby(cpm.suspend);
+ break;
+ }
+
+ return 0;
+}
+
+static struct platform_suspend_ops cpm_suspend_ops = {
+ .valid = cpm_suspend_valid,
+ .enter = cpm_suspend_enter,
+};
+
+static int cpm_get_uint_property(struct device_node *np,
+ const char *name)
+{
+ int len;
+ const unsigned int *prop = of_get_property(np, name, &len);
+
+ if (prop == NULL || len < sizeof(u32))
+ return 0;
+
+ return *prop;
+}
+
+static int __init cpm_init(void)
+{
+ struct device_node *np;
+ int dcr_base, dcr_len;
+ int ret = 0;
+
+ if (!cpm.powersave_off) {
+ cpm_idle_config(CPM_IDLE_WAIT);
+ ppc_md.power_save = &cpm_idle;
+ }
+
+ np = of_find_compatible_node(NULL, NULL, "ibm,cpm");
+ if (!np) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ dcr_base = dcr_resource_start(np, 0);
+ dcr_len = dcr_resource_len(np, 0);
+
+ if (dcr_base == 0 || dcr_len == 0) {
+ printk(KERN_ERR "cpm: could not parse dcr property for %s\n",
+ np->full_name);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ cpm.dcr_host = dcr_map(np, dcr_base, dcr_len);
+
+ if (!DCR_MAP_OK(cpm.dcr_host)) {
+ printk(KERN_ERR "cpm: failed to map dcr property for %s\n",
+ np->full_name);
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* All 4xx SoCs with a CPM controller have one of two
+ * different order for the CPM registers. Some have the
+ * CPM registers in the following order (ER,FR,SR). The
+ * others have them in the following order (SR,ER,FR).
+ */
+
+ if (cpm_get_uint_property(np, "er-offset") == 0) {
+ cpm.dcr_offset[CPM_ER] = 0;
+ cpm.dcr_offset[CPM_FR] = 1;
+ cpm.dcr_offset[CPM_SR] = 2;
+ } else {
+ cpm.dcr_offset[CPM_ER] = 1;
+ cpm.dcr_offset[CPM_FR] = 2;
+ cpm.dcr_offset[CPM_SR] = 0;
+ }
+
+ /* Now let's see what IPs to turn off for the following modes */
+
+ cpm.unused = cpm_get_uint_property(np, "unused-units");
+ cpm.idle_doze = cpm_get_uint_property(np, "idle-doze");
+ cpm.standby = cpm_get_uint_property(np, "standby");
+ cpm.suspend = cpm_get_uint_property(np, "suspend");
+
+ /* If some IPs are unused let's turn them off now */
+
+ if (cpm.unused) {
+ cpm_set(CPM_ER, cpm.unused);
+ cpm_set(CPM_FR, cpm.unused);
+ }
+
+ /* Now let's export interfaces */
+
+ if (!cpm.powersave_off && cpm.idle_doze)
+ cpm_idle_config_sysfs();
+
+ if (cpm.standby || cpm.suspend)
+ suspend_set_ops(&cpm_suspend_ops);
+out:
+ if (np)
+ of_node_put(np);
+ return ret;
+}
+
+late_initcall(cpm_init);
+
+static int __init cpm_powersave_off(char *arg)
+{
+ cpm.powersave_off = 1;
+ return 0;
+}
+__setup("powersave=off", cpm_powersave_off);
projects / linux-drm-fsl-dcu.git / commitdiff