On Mon, Oct 10 2016 at 04:01 -0600, Ulf Hansson wrote:
On 8 October 2016 at 00:36, Lina Iyer <lina.iyer@xxxxxxxxxx> wrote:
This patch allows domains to define idle states in the DT. SoC's can
define domain idle states in DT using the "domain-idle-states" property
of the domain provider. Add API to read the idle states from DT that can
be set in the genpd object.
This patch is based on the original patch by Marc Titinger.
Signed-off-by: Marc Titinger <mtitinger+renesas@xxxxxxxxxxxx>
Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Signed-off-by: Lina Iyer <lina.iyer@xxxxxxxxxx>
---
drivers/base/power/domain.c | 95 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/pm_domain.h | 8 ++++
2 files changed, 103 insertions(+)
diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 4e87170..4208b67 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1917,6 +1917,101 @@ out:
return ret ? -EPROBE_DEFER : 0;
}
EXPORT_SYMBOL_GPL(genpd_dev_pm_attach);
+
+static const struct of_device_id idle_state_match[] = {
+ { .compatible = "arm,idle-state", },
+ { }
+};
+
+static int genpd_parse_state(struct genpd_power_state *genpd_state,
+ struct device_node *state_node)
+{
+ int err;
+ u32 residency;
+ u32 entry_latency, exit_latency;
+ const struct of_device_id *match_id;
+
+ match_id = of_match_node(idle_state_match, state_node);
+ if (!match_id)
+ return -EINVAL;
+
+ err = of_property_read_u32(state_node, "entry-latency-us",
+ &entry_latency);
+ if (err) {
+ pr_debug(" * %s missing entry-latency-us property\n",
+ state_node->full_name);
+ return -EINVAL;
+ }
+
+ err = of_property_read_u32(state_node, "exit-latency-us",
+ &exit_latency);
+ if (err) {
+ pr_debug(" * %s missing exit-latency-us property\n",
+ state_node->full_name);
+ return -EINVAL;
+ }
+
+ err = of_property_read_u32(state_node, "min-residency-us", &residency);
+ if (!err)
+ genpd_state->residency_ns = 1000 * residency;
+
+ genpd_state->power_on_latency_ns = 1000 * exit_latency;
+ genpd_state->power_off_latency_ns = 1000 * entry_latency;
+
+ return 0;
+}
+
+/**
+ * of_genpd_parse_idle_states: Return array of idle states for the genpd.
+ *
+ * @dn: The genpd device node
+ * @states: The pointer to which the state array will be saved.
+ * @n: The count of elements in the array returned from this function.
+ *
+ * Returns the device states parsed from the OF node. The memory for the states
+ * is allocated by this function and is the responsibility of the caller to
+ * free the memory after use.
+ */
+int of_genpd_parse_idle_states(struct device_node *dn,
+ struct genpd_power_state **states, int *n)
Instead of taking **states as a parameter, let's instead return it as
a pointer for the allocated struct. In case of failures, let's return
ERR_PTR().
Hmm.. I thought about it. There are 2 return values from this function.
If we return a pointer to the allocated memory, we still have to return
the size of it as an argument. I wasn't happy splitting the return
values in 2 different places.
+{
+ struct genpd_power_state *st;
+ struct device_node *np;
+ int i = 0;
+ int err, ret;
+ int count;
+ struct of_phandle_iterator it;
+
+ count = of_count_phandle_with_args(dn, "domain-idle-states", NULL);
If count is zero or an error, we should return an error code (ERR_PTR()). Right?
OK
+
+ st = kcalloc(count, sizeof(*st), GFP_KERNEL);
+ if (!st)
+ return -ENOMEM;
+
+ /* Loop over the phandles until all the requested entry is found */
+ of_for_each_phandle(&it, err, dn, "domain-idle-states", NULL, 0) {
+ np = of_node_get(it.node);
I don't think you need to increment the usage count for the device
node as that is already managed by of_for_each_phandle().
It's only in the error case below, when it's needed.
Hmm.. Didn't realize that.. will fix.
+ ret = genpd_parse_state(&st[i++], np);
+ if (ret) {
+ pr_err
+ ("Parsing idle state node %s failed with err %d\n",
+ np->full_name, ret);
+ of_node_put(np);
+ goto fail;
The goto seems unnecessary. Why not deal with all error handling here
and return the error code?
+ }
+ of_node_put(np);
According the comment above, you should be able to remove this.
+ }
+
+ *n = count;
+ *states = st;
+
+ return 0;
+fail:
+ kfree(st);
+ return ret;
+}
+EXPORT_SYMBOL(of_genpd_parse_idle_states);
Please use EXPORT_SYMBOL_GPL() instead.
Hmm.. OK
Thanks,
Lina
+
#endif /* CONFIG_PM_GENERIC_DOMAINS_OF */
diff --git a/include/linux/pm_domain.h b/include/linux/pm_domain.h
index f4492eb..b489496 100644
--- a/include/linux/pm_domain.h
+++ b/include/linux/pm_domain.h
@@ -205,6 +205,8 @@ extern int of_genpd_add_device(struct of_phandle_args *args,
extern int of_genpd_add_subdomain(struct of_phandle_args *parent,
struct of_phandle_args *new_subdomain);
extern struct generic_pm_domain *of_genpd_remove_last(struct device_node *np);
+extern int of_genpd_parse_idle_states(struct device_node *dn,
+ struct genpd_power_state **states, int *n);
int genpd_dev_pm_attach(struct device *dev);
#else /* !CONFIG_PM_GENERIC_DOMAINS_OF */
@@ -234,6 +236,12 @@ static inline int of_genpd_add_subdomain(struct of_phandle_args *parent,
return -ENODEV;
}
+static inline int of_genpd_parse_idle_states(struct device_node *dn,
+ struct genpd_power_state **states, int *n)
+{
+ return -ENODEV;
+}
+
static inline int genpd_dev_pm_attach(struct device *dev)
{
return -ENODEV;
--
2.7.4
Kind regards
Uffe
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