There could be single power domain or multiple power domains associated
with a clock controller. Add powerdomain_class support which would help
vote/unvote for any power domain performance state for a clock frequency
to the genpd framework.
A clock frequency request from a consumer would look for the corresponding
performance corner and thus would aggregate and request the desired
performance state to genpd.
Signed-off-by: Taniya Das <tdas@xxxxxxxxxxxxxx>
---
drivers/clk/qcom/Makefile | 1 +
drivers/clk/qcom/clk-pd.c | 193 ++++++++++++++++++++++++++++++++++++++++++++++
drivers/clk/qcom/clk-pd.h | 55 +++++++++++++
3 files changed, 249 insertions(+)
create mode 100644 drivers/clk/qcom/clk-pd.c
create mode 100644 drivers/clk/qcom/clk-pd.h
diff --git a/drivers/clk/qcom/Makefile b/drivers/clk/qcom/Makefile
index 599ab91..336d4da 100644
--- a/drivers/clk/qcom/Makefile
+++ b/drivers/clk/qcom/Makefile
@@ -12,6 +12,7 @@ clk-qcom-y += clk-regmap-divider.o
clk-qcom-y += clk-regmap-mux.o
clk-qcom-y += clk-regmap-mux-div.o
clk-qcom-y += reset.o
+clk-qcom-y += clk-pd.o
clk-qcom-$(CONFIG_QCOM_GDSC) += gdsc.o
# Keep alphabetically sorted by config
diff --git a/drivers/clk/qcom/clk-pd.c b/drivers/clk/qcom/clk-pd.c
new file mode 100644
index 0000000..d1f9df3
--- /dev/null
+++ b/drivers/clk/qcom/clk-pd.c
@@ -0,0 +1,193 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2018, The Linux Foundation. All rights reserved.
+ */
+
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/pm_domain.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+
+#include "clk-pd.h"
+#include "clk-regmap.h"
+
+struct clk_powerdomain {
+ struct list_head list;
+ struct clk_powerdomain_class *pd;
+};
+
+static LIST_HEAD(clk_pd_list);
+
+/* Find the corner required for a given clock rate */
+static int find_rate_to_corner(struct clk_regmap *rclk, unsigned long rate)
+{
+ int corner;
+
+ for (corner = 0; corner < rclk->pd->num_corners; corner++)
+ if (rate <= rclk->rate_max[corner])
+ break;
+
+ if (corner == rclk->pd->num_corners) {
+ pr_debug("Rate %lu for %s is > than highest Fmax\n", rate,
+ rclk->hw.init->name);
+ return -EINVAL;
+ }
+
+ return corner;
+}
+
+static int pd_update_corner_state(struct clk_powerdomain_class *pd)
+{
+ int corner, ret, *state = pd->corner, i;
+ int cur_corner = pd->cur_corner, max_corner = pd->num_corners - 1;
+
+ /* Aggregate the corner */
+ for (corner = max_corner; corner > 0; corner--) {
+ if (pd->corner_votes[corner])
+ break;
+ }
+
+ if (corner == cur_corner)
+ return 0;
+
+ pr_debug("Set performance state to genpd(%s) for state %d, cur_corner %d, num_corner %d\n",
+ pd->pd_name, state[corner], cur_corner, pd->num_corners);
+
+ for (i = 0; i < pd->num_pd; i++) {
+ ret = dev_pm_genpd_set_performance_state(pd->powerdomain_dev[i],
+ state[corner]);
+ if (ret)
+ return ret;
+
+ if (cur_corner == 0 || cur_corner == pd->num_corners) {
+ pd->links[i] = device_link_add(pd->dev,
+ pd->powerdomain_dev[i],
+ DL_FLAG_STATELESS |
+ DL_FLAG_PM_RUNTIME |
+ DL_FLAG_RPM_ACTIVE);
+ if (!pd->links[i])
+ pr_err("Links for %d not created\n", i);
+ }
+
+ if (corner == 0)
+ device_link_del(pd->links[i]);
+ }
+
+ pd->cur_corner = corner;
+
+ return 0;
+}
+
+/* call from prepare & set rate */
+int clk_power_domain_vote_rate(struct clk_regmap *rclk,
+ unsigned long rate)
+{
+ int corner;
+
+ if (!rclk->pd)
+ return 0;
+
+ corner = find_rate_to_corner(rclk, rate);
+ if (corner < 0)
+ return corner;
+
+ mutex_lock(&rclk->pd->lock);
+
+ rclk->pd->corner_votes[corner]++;
+
+ /* update the corner to power domain */
+ if (pd_update_corner_state(rclk->pd) < 0)
+ rclk->pd->corner_votes[corner]--;
+
+ pr_debug("pd(%s) prepare corner_votes_count %d, corner %d\n",
+ rclk->pd->pd_name, rclk->pd->corner_votes[corner],
+ corner);
+
+ mutex_unlock(&rclk->pd->lock);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(clk_power_domain_vote_rate);
+
+/* call from unprepare & set rate */
+void clk_power_domain_unvote_rate(struct clk_regmap *rclk,
+ unsigned long rate)
+{
+ int corner;
+
+ if (!rclk->pd)
+ return;
+
+ corner = find_rate_to_corner(rclk, rate);
+ if (corner < 0)
+ return;
+
+ if (WARN(!rclk->pd->corner_votes[corner],
+ "Reference counts are incorrect for %s corner %d\n",
+ rclk->pd->pd_name, corner))
+ return;
+
+ mutex_lock(&rclk->pd->lock);
+
+ rclk->pd->corner_votes[corner]--;
+
+ if (pd_update_corner_state(rclk->pd) < 0)
+ rclk->pd->corner_votes[corner]++;
+
+ pr_debug("pd(%s) unprepare corner_votes_count %d, corner %d\n",
+ rclk->pd->pd_name, rclk->pd->corner_votes[corner],
+ corner);
+
+ mutex_unlock(&rclk->pd->lock);
+}
+EXPORT_SYMBOL_GPL(clk_power_domain_unvote_rate);
+
+int clk_power_domain_class_init(struct device *dev,
+ struct clk_powerdomain_class *pd)
+{
+ struct clk_powerdomain *pwrd;
+ int i, num_domains;
+
+ if (!pd) {
+ pr_debug("pd not defined\n");
+ return 0;
+ }
+
+ /* Deal only with devices using multiple PM domains. */
+ num_domains = of_count_phandle_with_args(dev->of_node, "power-domains",
+ "#power-domain-cells");
+
+ list_for_each_entry(pwrd, &clk_pd_list, list) {
+ if (pwrd->pd == pd)
+ return 0;
+ }
+
+ pr_debug("Voting for pd_class %s\n", pd->pd_name);
+
+ if (num_domains == 1) {
+ pd->powerdomain_dev[0] = dev;
+ } else {
+ for (i = 0; i < pd->num_pd; i++) {
+ int index = pd->pd_index[i];
+
+ pd->powerdomain_dev[i] = genpd_dev_pm_attach_by_id(dev,
+ index);
+ }
+ }
+
+ pwrd = kmalloc(sizeof(*pwrd), GFP_KERNEL);
+ if (!pwrd)
+ return -ENOMEM;
+
+ pwrd->pd = pd;
+ list_add_tail(&pwrd->list, &clk_pd_list);
+
+ pd->dev = dev;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(clk_power_domain_class_init);
+
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/clk/qcom/clk-pd.h b/drivers/clk/qcom/clk-pd.h
new file mode 100644
index 0000000..addde4f
--- /dev/null
+++ b/drivers/clk/qcom/clk-pd.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/* Copyright (c) 2018, The Linux Foundation. All rights reserved. */
+
+struct clk_regmap;
+
+/**
+ * struct clk_powerdomain_class - Power Domain scaling class
+ * @pd_name: name of the power domain class
+ * @dev: clock controller device
+ * @powerdomain_dev: array of power domain devices
+ * @links: array of power domain devices linked
+ * @num_pd: size of power domain devices array
+ * @pd_index: array of power domain index which would
+ * be used to attach the power domain using
+ * genpd_dev_pm_attach_by_id(dev, index)
+ * @corner: sorted 2D array of legal corner settings,
+ indexed by the corner
+ * @corner_votes: array of votes for each corner
+ * @num_corner: specifies the size of corner_votes array
+ * @cur_corner: current set power domain corner
+ * @lock: lock to protect this struct
+ */
+struct clk_powerdomain_class {
+ const char *pd_name;
+ struct device *dev;
+ struct device **powerdomain_dev;
+ struct device_link **links;
+ int num_pd;
+ int *pd_index;
+ int *corner;
+ int *corner_votes;
+ int num_corners;
+ unsigned int cur_corner;
+ /* Protect this struct */
+ struct mutex lock;
+};
+
+#define CLK_POWERDOMAIN_INIT(_name, _num_corners, _num_pd, _corner) \
+ struct clk_powerdomain_class _name = { \
+ .pd_name = #_name, \
+ .powerdomain_dev = (struct device *([_num_pd])) {}, \
+ .links = (struct device_link *([_num_pd])) {}, \
+ .num_pd = _num_pd, \
+ .pd_index = (int [_num_pd]) {}, \
+ .corner_votes = (int [_num_corners]) {}, \
+ .num_corners = _num_corners, \
+ .corner = _corner, \
+ .cur_corner = _num_corners, \
+ .lock = __MUTEX_INITIALIZER(_name.lock) \
+ }
+
+int clk_power_domain_class_init(struct device *dev,
+ struct clk_powerdomain_class *pd);
+int clk_power_domain_vote_rate(struct clk_regmap *rclk, unsigned long rate);
+void clk_power_domain_unvote_rate(struct clk_regmap *rclk, unsigned long rate);
--
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