MIPS: Alchemy: new userspace suspend interface for development boards.
Replace the current sysctl-based suspend interface with a new sysfs-
based one which also uses the Linux-2.6 suspend model.
To configure wakeup sources, a subtree for the demoboards is created
under /sys/power/db1x:
sys/
`-- power
`-- db1x
|-- gpio0
|-- gpio1
|-- gpio2
|-- gpio3
|-- gpio4
|-- gpio5
|-- gpio6
|-- gpio7
|-- timer
|-- timer_timeout
|-- wakemsk
`-- wakesrc
The nodes 'gpio[0-7]' and 'timer' configure the GPIO0..7 and M2
bits of the SYS_WAKEMSK (wakeup source enable) register. Writing '1'
enables a wakesource, 0 disables it.
The 'timer_timeout' node holds the timeout in seconds after which the
TOYMATCH2 event should wake the system.
The 'wakesrc' node holds the SYS_WAKESRC register after wakeup (in hex),
the 'wakemsk' node can be used to get/set the wakeup mask directly.
For example, to have the timer wake the system after 10 seconds of sleep,
the following must be done in userspace:
echo 10 > /sys/power/db1x/timer_timeout
echo 1 > /sys/power/db1x/timer
echo mem > /sys/power/sleep
This patch also removes the homebrew CPU frequency switching code. I don't
understand how it could have ever worked reliably; it does not communicate
the clock changes to peripheral devices other than uarts.
Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
create mode 100644 arch/mips/alchemy/devboards/pm.c
diff --git a/arch/mips/alchemy/devboards/pm.c b/arch/mips/alchemy/devboards/pm.c
new file mode 100644
index 0000000..d5eb9c3
--- /dev/null
+++ b/arch/mips/alchemy/devboards/pm.c
@@ -0,0 +1,229 @@
+/*
+ * Alchemy Development Board example suspend userspace interface.
+ *
+ * (c) 2008 Manuel Lauss <mano@roarinelk.homelinux.net>
+ */
+
+#include <linux/init.h>
+#include <linux/kobject.h>
+#include <linux/suspend.h>
+#include <linux/sysfs.h>
+#include <asm/mach-au1x00/au1000.h>
+
+/*
+ * Generic suspend userspace interface for Alchemy development boards.
+ * This code exports a few sysfs nodes under /sys/power/db1x/ which
+ * can be used by userspace to en/disable all au1x-provided wakeup
+ * sources and configure the timeout after which the the TOYMATCH2 irq
+ * is to trigger a wakeup.
+ */
+
+
+static unsigned long db1x_pm_sleep_secs;
+static unsigned long db1x_pm_wakemsk;
+static unsigned long db1x_pm_last_wakesrc;
+
+static int db1x_pm_enter(suspend_state_t state)
+{
+ /* enable GPIO based wakeup */
+ au_writel(1, SYS_PININPUTEN);
+
+ /* clear and setup wake cause and source */
+ au_writel(0, SYS_WAKEMSK);
+ au_sync();
+ au_writel(0, SYS_WAKESRC);
+ au_sync();
+
+ au_writel(db1x_pm_wakemsk, SYS_WAKEMSK);
+ au_sync();
+
+ /* setup 1Hz-timer-based wakeup: wait for reg access */
+ while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20)
+ asm volatile ("nop");
+
+ au_writel(au_readl(SYS_TOYREAD) + db1x_pm_sleep_secs, SYS_TOYMATCH2);
+ au_sync();
+
+ /* wait for value to really hit the register */
+ while (au_readl(SYS_COUNTER_CNTRL) & SYS_CNTRL_M20)
+ asm volatile ("nop");
+
+ /* ...and now the sandman can come! */
+ au_sleep();
+
+ return 0;
+}
+
+static int db1x_pm_begin(suspend_state_t state)
+{
+ if (!db1x_pm_wakemsk) {
+ printk(KERN_ERR "db1x: no wakeup source activated!\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static void db1x_pm_end(void)
+{
+ /* read and store wakeup source, the clear the register. To
+ * be able to clear it, WAKEMSK must be cleared first.
+ */
+ db1x_pm_last_wakesrc = au_readl(SYS_WAKESRC);
+
+ au_writel(0, SYS_WAKEMSK);
+ au_writel(0, SYS_WAKESRC);
+ au_sync();
+
+}
+
+static struct platform_suspend_ops db1x_pm_ops = {
+ .valid = suspend_valid_only_mem,
+ .begin = db1x_pm_begin,
+ .enter = db1x_pm_enter,
+ .end = db1x_pm_end,
+};
+
+#define ATTRCMP(x) (0 == strcmp(attr->attr.name, #x))
+
+static ssize_t db1x_pmattr_show(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ char *buf)
+{
+ int idx;
+
+ if (ATTRCMP(timer_timeout))
+ return sprintf(buf, "%lu\n", db1x_pm_sleep_secs);
+
+ else if (ATTRCMP(timer))
+ return sprintf(buf, "%u\n",
+ !!(db1x_pm_wakemsk & SYS_WAKEMSK_M2));
+
+ else if (ATTRCMP(wakesrc))
+ return sprintf(buf, "%lu\n", db1x_pm_last_wakesrc);
+
+ else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
+ ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
+ ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
+ idx = (attr->attr.name)[4] - '0';
+ return sprintf(buf, "%d\n",
+ !!(db1x_pm_wakemsk & SYS_WAKEMSK_GPIO(idx)));
+
+ } else if (ATTRCMP(wakemsk)) {
+ return sprintf(buf, "%08lx\n", db1x_pm_wakemsk);
+ }
+
+ return -ENOENT;
+}
+
+static ssize_t db1x_pmattr_store(struct kobject *kobj,
+ struct kobj_attribute *attr,
+ const char *instr,
+ size_t bytes)
+{
+ unsigned long l;
+ int tmp;
+
+ if (ATTRCMP(timer_timeout)) {
+ tmp = strict_strtoul(instr, 0, &l);
+ if (tmp)
+ return tmp;
+
+ db1x_pm_sleep_secs = l;
+
+ } else if (ATTRCMP(timer)) {
+ if (instr[0] != '0')
+ db1x_pm_wakemsk |= SYS_WAKEMSK_M2;
+ else
+ db1x_pm_wakemsk &= ~SYS_WAKEMSK_M2;
+
+ } else if (ATTRCMP(gpio0) || ATTRCMP(gpio1) || ATTRCMP(gpio2) ||
+ ATTRCMP(gpio3) || ATTRCMP(gpio4) || ATTRCMP(gpio5) ||
+ ATTRCMP(gpio6) || ATTRCMP(gpio7)) {
+ tmp = (attr->attr.name)[4] - '0';
+ if (instr[0] != '0') {
+ db1x_pm_wakemsk |= SYS_WAKEMSK_GPIO(tmp);
+ } else {
+ db1x_pm_wakemsk &= ~SYS_WAKEMSK_GPIO(tmp);
+ }
+
+ } else if (ATTRCMP(wakemsk)) {
+ tmp = strict_strtoul(instr, 0, &l);
+ if (tmp)
+ return tmp;
+
+ db1x_pm_wakemsk = l & 0x0000003f;
+
+ } else
+ bytes = -ENOENT;
+
+ return bytes;
+}
+
+#define ATTR(x) \
+ static struct kobj_attribute x##_attribute = \
+ __ATTR(x, 0664, db1x_pmattr_show, \
+ db1x_pmattr_store);
+
+ATTR(gpio0) /* GPIO-based wakeup enable */
+ATTR(gpio1)
+ATTR(gpio2)
+ATTR(gpio3)
+ATTR(gpio4)
+ATTR(gpio5)
+ATTR(gpio6)
+ATTR(gpio7)
+ATTR(timer) /* TOYMATCH2-based wakeup enable */
+ATTR(timer_timeout) /* timer-based wakeup timeout value, in seconds */
+ATTR(wakesrc) /* contents of SYS_WAKESRC after last wakeup */
+ATTR(wakemsk) /* direct access to SYS_WAKEMSK */
+
+#define ATTR_LIST(x) & x ## _attribute.attr
+static struct attribute *db1x_pmattrs[] = {
+ ATTR_LIST(gpio0),
+ ATTR_LIST(gpio1),
+ ATTR_LIST(gpio2),
+ ATTR_LIST(gpio3),
+ ATTR_LIST(gpio4),
+ ATTR_LIST(gpio5),
+ ATTR_LIST(gpio6),
+ ATTR_LIST(gpio7),
+ ATTR_LIST(timer),
+ ATTR_LIST(timer_timeout),
+ ATTR_LIST(wakesrc),
+ ATTR_LIST(wakemsk),
+ NULL, /* terminator */
+};
+
+static struct attribute_group db1x_pmattr_group = {
+ .name = "db1x",
+ .attrs = db1x_pmattrs,
+};
+
+/*
+ * Initialize suspend interface
+ */
+static int __init pm_init(void)
+{
+ /* init TOY to tick at 1Hz if not already done. No need to wait
+ * for confirmation since there's plenty of time from here to
+ * the next suspend cycle.
+ */
+ if (au_readl(SYS_TOYTRIM) != 32767) {
+ au_writel(32767, SYS_TOYTRIM);
+ au_sync();
+ }
+
+ db1x_pm_last_wakesrc = au_readl(SYS_WAKESRC);
+
+ au_writel(0, SYS_WAKESRC);
+ au_sync();
+ au_writel(0, SYS_WAKEMSK);
+ au_sync();
+
+ suspend_set_ops(&db1x_pm_ops);
+
+ return sysfs_create_group(power_kobj, &db1x_pmattr_group);
+}
+
+late_initcall(pm_init);