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path: root/drivers/interconnect/icc-clk.c
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-rw-r--r--drivers/interconnect/icc-clk.c174
1 files changed, 174 insertions, 0 deletions
diff --git a/drivers/interconnect/icc-clk.c b/drivers/interconnect/icc-clk.c
new file mode 100644
index 000000000000..4d43ebff4257
--- /dev/null
+++ b/drivers/interconnect/icc-clk.c
@@ -0,0 +1,174 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (c) 2023, Linaro Ltd.
+ */
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/interconnect-clk.h>
+#include <linux/interconnect-provider.h>
+
+struct icc_clk_node {
+ struct clk *clk;
+ bool enabled;
+};
+
+struct icc_clk_provider {
+ struct icc_provider provider;
+ int num_clocks;
+ struct icc_clk_node clocks[];
+};
+
+#define to_icc_clk_provider(_provider) \
+ container_of(_provider, struct icc_clk_provider, provider)
+
+static int icc_clk_set(struct icc_node *src, struct icc_node *dst)
+{
+ struct icc_clk_node *qn = src->data;
+ int ret;
+
+ if (!qn || !qn->clk)
+ return 0;
+
+ if (!src->peak_bw) {
+ if (qn->enabled)
+ clk_disable_unprepare(qn->clk);
+ qn->enabled = false;
+
+ return 0;
+ }
+
+ if (!qn->enabled) {
+ ret = clk_prepare_enable(qn->clk);
+ if (ret)
+ return ret;
+ qn->enabled = true;
+ }
+
+ return clk_set_rate(qn->clk, icc_units_to_bps(src->peak_bw));
+}
+
+static int icc_clk_get_bw(struct icc_node *node, u32 *avg, u32 *peak)
+{
+ struct icc_clk_node *qn = node->data;
+
+ if (!qn || !qn->clk)
+ *peak = INT_MAX;
+ else
+ *peak = Bps_to_icc(clk_get_rate(qn->clk));
+
+ return 0;
+}
+
+/**
+ * icc_clk_register() - register a new clk-based interconnect provider
+ * @dev: device supporting this provider
+ * @first_id: an ID of the first provider's node
+ * @num_clocks: number of instances of struct icc_clk_data
+ * @data: data for the provider
+ *
+ * Registers and returns a clk-based interconnect provider. It is a simple
+ * wrapper around COMMON_CLK framework, allowing other devices to vote on the
+ * clock rate.
+ *
+ * Return: 0 on success, or an error code otherwise
+ */
+struct icc_provider *icc_clk_register(struct device *dev,
+ unsigned int first_id,
+ unsigned int num_clocks,
+ const struct icc_clk_data *data)
+{
+ struct icc_clk_provider *qp;
+ struct icc_provider *provider;
+ struct icc_onecell_data *onecell;
+ struct icc_node *node;
+ int ret, i, j;
+
+ onecell = devm_kzalloc(dev, struct_size(onecell, nodes, 2 * num_clocks), GFP_KERNEL);
+ if (!onecell)
+ return ERR_PTR(-ENOMEM);
+
+ qp = devm_kzalloc(dev, struct_size(qp, clocks, num_clocks), GFP_KERNEL);
+ if (!qp)
+ return ERR_PTR(-ENOMEM);
+
+ qp->num_clocks = num_clocks;
+
+ provider = &qp->provider;
+ provider->dev = dev;
+ provider->get_bw = icc_clk_get_bw;
+ provider->set = icc_clk_set;
+ provider->aggregate = icc_std_aggregate;
+ provider->xlate = of_icc_xlate_onecell;
+ INIT_LIST_HEAD(&provider->nodes);
+ provider->data = onecell;
+
+ icc_provider_init(provider);
+
+ for (i = 0, j = 0; i < num_clocks; i++) {
+ qp->clocks[i].clk = data[i].clk;
+
+ node = icc_node_create(first_id + j);
+ if (IS_ERR(node)) {
+ ret = PTR_ERR(node);
+ goto err;
+ }
+
+ node->name = devm_kasprintf(dev, GFP_KERNEL, "%s_master", data[i].name);
+ node->data = &qp->clocks[i];
+ icc_node_add(node, provider);
+ /* link to the next node, slave */
+ icc_link_create(node, first_id + j + 1);
+ onecell->nodes[j++] = node;
+
+ node = icc_node_create(first_id + j);
+ if (IS_ERR(node)) {
+ ret = PTR_ERR(node);
+ goto err;
+ }
+
+ node->name = devm_kasprintf(dev, GFP_KERNEL, "%s_slave", data[i].name);
+ /* no data for slave node */
+ icc_node_add(node, provider);
+ onecell->nodes[j++] = node;
+ }
+
+ onecell->num_nodes = j;
+
+ ret = icc_provider_register(provider);
+ if (ret)
+ goto err;
+
+ return provider;
+
+err:
+ icc_nodes_remove(provider);
+
+ return ERR_PTR(ret);
+}
+EXPORT_SYMBOL_GPL(icc_clk_register);
+
+/**
+ * icc_clk_unregister() - unregister a previously registered clk interconnect provider
+ * @provider: provider returned by icc_clk_register()
+ */
+void icc_clk_unregister(struct icc_provider *provider)
+{
+ struct icc_clk_provider *qp = container_of(provider, struct icc_clk_provider, provider);
+ int i;
+
+ icc_provider_deregister(&qp->provider);
+ icc_nodes_remove(&qp->provider);
+
+ for (i = 0; i < qp->num_clocks; i++) {
+ struct icc_clk_node *qn = &qp->clocks[i];
+
+ if (qn->enabled)
+ clk_disable_unprepare(qn->clk);
+ }
+}
+EXPORT_SYMBOL_GPL(icc_clk_unregister);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Interconnect wrapper for clocks");
+MODULE_AUTHOR("Dmitry Baryshkov <dmitry.baryshkov@linaro.org>");