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author | Michael Ellerman <mpe@ellerman.id.au> | 2017-08-08 08:39:20 +0200 |
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committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-08-10 15:31:30 +0200 |
commit | bfa9a2eb925422b05b99c3b64a8f757025319f59 (patch) | |
tree | bacc42fcec14db7a880315868da0c5ac1039d46b /arch/powerpc/platforms/4xx/cpm.c | |
parent | powerpc/44x: Move 44x machine check handlers into platforms/44x (diff) | |
download | linux-bfa9a2eb925422b05b99c3b64a8f757025319f59.tar.xz linux-bfa9a2eb925422b05b99c3b64a8f757025319f59.zip |
powerpc/4xx: Create 4xx pseudo-platform in platforms/4xx
We have a lot of code in sysdev for supporting 4xx, ie. either 40x or
44x. Instead it would be cleaner if it was all in platforms/4xx.
This is slightly odd in that we don't actually define any machines in
the 4xx platform, as is usual for a platform directory. But still it
seems like a better result to have all this related code in a directory
by itself.
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/platforms/4xx/cpm.c')
-rw-r--r-- | arch/powerpc/platforms/4xx/cpm.c | 346 |
1 files changed, 346 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/4xx/cpm.c b/arch/powerpc/platforms/4xx/cpm.c new file mode 100644 index 000000000000..ba95adf81d8d --- /dev/null +++ b/arch/powerpc/platforms/4xx/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 device *dev; + unsigned long ret; + + dev = get_cpu_device(0); + + ret = sysfs_create_file(&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 node_put; + } + + 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 node_put; + } + + /* 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); +node_put: + of_node_put(np); +out: + 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); |