powerpc/4xx: Add suspend and idle support

Add suspend/resume support for 4xx compatible CPUs.
See /sys/power/state for available power states configured in.

Add two different idle states (idle-wait and idle-doze) controlled via sysfs.
Default is idle-wait.
	cat /sys/devices/system/cpu/cpu0/idle
	[wait] doze

To save additional power, use idle-doze.
	echo doze > /sys/devices/system/cpu/cpu0/idle
	cat /sys/devices/system/cpu/cpu0/idle
	wait [doze]

Signed-off-by: Victor Gallardo <vgallardo@apm.com>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>

5 files changed, 413 insertions, 4 deletions

diff --git a/Documentation/powerpc/dts-bindings/4xx/cpm.txt b/Documentation/powerpc/dts-bindings/4xx/cpm.txt
new file mode 100644
index 000000000000..ee459806d35e
--- /dev/null
+++ b/Documentation/powerpc/dts-bindings/4xx/cpm.txt
@@ -0,0 +1,52 @@
+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>;
+};
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 06d742c3fbcf..e16b4988f825 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -212,7 +212,7 @@ config ARCH_HIBERNATION_POSSIBLE
 config ARCH_SUSPEND_POSSIBLE
         def_bool y
         depends on ADB_PMU || PPC_EFIKA || PPC_LITE5200 || PPC_83xx || \
-                   PPC_85xx || PPC_86xx || PPC_PSERIES
+                   PPC_85xx || PPC_86xx || PPC_PSERIES || 44x || 40x
 
 config PPC_DCR_NATIVE
         bool
@@ -598,13 +598,11 @@ config EXTRA_TARGETS
 
           If unsure, leave blank
 
-if !44x || BROKEN
 config ARCH_WANTS_FREEZER_CONTROL
         def_bool y
         depends on ADB_PMU
 
 source kernel/power/Kconfig
-endif
 
 config SECCOMP
         bool "Enable seccomp to safely compute untrusted bytecode"
@@ -685,6 +683,15 @@ config FSL_PMC
           Freescale MPC85xx/MPC86xx power management controller support
           (suspend/resume). For MPC83xx see platforms/83xx/suspend.c
 
+config PPC4xx_CPM
+        bool
+        default y
+        depends on SUSPEND && (44x || 40x)
+        help
+          PPC4xx Clock Power Management (CPM) support (suspend/resume).
+          It also enables support for two different idle states (idle-wait
+          and idle-doze).
+
 config 4xx_SOC
         bool
 
diff --git a/arch/powerpc/platforms/44x/Makefile b/arch/powerpc/platforms/44x/Makefile
index 82ff326e0795..c04d16df8488 100644
--- a/arch/powerpc/platforms/44x/Makefile
+++ b/arch/powerpc/platforms/44x/Makefile
@@ -1,4 +1,7 @@
-obj-$(CONFIG_44x)       := misc_44x.o idle.o
+obj-$(CONFIG_44x)       += misc_44x.o
+ifneq ($(CONFIG_PPC4xx_CPM),y)
+obj-$(CONFIG_44x)       += idle.o
+endif
 obj-$(CONFIG_PPC44x_SIMPLE) += ppc44x_simple.o
 obj-$(CONFIG_EBONY)     += ebony.o
 obj-$(CONFIG_SAM440EP)  += sam440ep.o
diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile
index 0bef9dacb64e..9c2973479142 100644
--- a/arch/powerpc/sysdev/Makefile
+++ b/arch/powerpc/sysdev/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_OF_RTC)		+= of_rtc.o
 ifeq ($(CONFIG_PCI),y)
 obj-$(CONFIG_4xx)               += ppc4xx_pci.o
 endif
+obj-$(CONFIG_PPC4xx_CPM)        += ppc4xx_cpm.o
 obj-$(CONFIG_PPC4xx_GPIO)       += ppc4xx_gpio.o
 
 obj-$(CONFIG_CPM)               += cpm_common.o
diff --git a/arch/powerpc/sysdev/ppc4xx_cpm.c b/arch/powerpc/sysdev/ppc4xx_cpm.c
new file mode 100644
index 000000000000..73b86cc5ea74
--- /dev/null
+++ b/arch/powerpc/sysdev/ppc4xx_cpm.c
@@ -0,0 +1,346 @@
+/*
+ * 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);