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path: root/drivers/clk/clk-scmi.c
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Diffstat (limited to 'drivers/clk/clk-scmi.c')
-rw-r--r--drivers/clk/clk-scmi.c123
1 files changed, 98 insertions, 25 deletions
diff --git a/drivers/clk/clk-scmi.c b/drivers/clk/clk-scmi.c
index a2287c770d5c..2c7a830ce308 100644
--- a/drivers/clk/clk-scmi.c
+++ b/drivers/clk/clk-scmi.c
@@ -2,7 +2,7 @@
/*
* System Control and Power Interface (SCMI) Protocol based clock driver
*
- * Copyright (C) 2018 ARM Ltd.
+ * Copyright (C) 2018-2022 ARM Ltd.
*/
#include <linux/clk-provider.h>
@@ -13,11 +13,13 @@
#include <linux/scmi_protocol.h>
#include <asm/div64.h>
+static const struct scmi_clk_proto_ops *scmi_proto_clk_ops;
+
struct scmi_clk {
u32 id;
struct clk_hw hw;
const struct scmi_clock_info *info;
- const struct scmi_handle *handle;
+ const struct scmi_protocol_handle *ph;
};
#define to_scmi_clk(clk) container_of(clk, struct scmi_clk, hw)
@@ -29,7 +31,7 @@ static unsigned long scmi_clk_recalc_rate(struct clk_hw *hw,
u64 rate;
struct scmi_clk *clk = to_scmi_clk(hw);
- ret = clk->handle->clk_ops->rate_get(clk->handle, clk->id, &rate);
+ ret = scmi_proto_clk_ops->rate_get(clk->ph, clk->id, &rate);
if (ret)
return 0;
return rate;
@@ -69,68 +71,122 @@ static int scmi_clk_set_rate(struct clk_hw *hw, unsigned long rate,
{
struct scmi_clk *clk = to_scmi_clk(hw);
- return clk->handle->clk_ops->rate_set(clk->handle, clk->id, 0, rate);
+ return scmi_proto_clk_ops->rate_set(clk->ph, clk->id, rate);
}
static int scmi_clk_enable(struct clk_hw *hw)
{
struct scmi_clk *clk = to_scmi_clk(hw);
- return clk->handle->clk_ops->enable(clk->handle, clk->id);
+ return scmi_proto_clk_ops->enable(clk->ph, clk->id);
}
static void scmi_clk_disable(struct clk_hw *hw)
{
struct scmi_clk *clk = to_scmi_clk(hw);
- clk->handle->clk_ops->disable(clk->handle, clk->id);
+ scmi_proto_clk_ops->disable(clk->ph, clk->id);
+}
+
+static int scmi_clk_atomic_enable(struct clk_hw *hw)
+{
+ struct scmi_clk *clk = to_scmi_clk(hw);
+
+ return scmi_proto_clk_ops->enable_atomic(clk->ph, clk->id);
+}
+
+static void scmi_clk_atomic_disable(struct clk_hw *hw)
+{
+ struct scmi_clk *clk = to_scmi_clk(hw);
+
+ scmi_proto_clk_ops->disable_atomic(clk->ph, clk->id);
}
+/*
+ * We can provide enable/disable atomic callbacks only if the underlying SCMI
+ * transport for an SCMI instance is configured to handle SCMI commands in an
+ * atomic manner.
+ *
+ * When no SCMI atomic transport support is available we instead provide only
+ * the prepare/unprepare API, as allowed by the clock framework when atomic
+ * calls are not available.
+ *
+ * Two distinct sets of clk_ops are provided since we could have multiple SCMI
+ * instances with different underlying transport quality, so they cannot be
+ * shared.
+ */
static const struct clk_ops scmi_clk_ops = {
.recalc_rate = scmi_clk_recalc_rate,
.round_rate = scmi_clk_round_rate,
.set_rate = scmi_clk_set_rate,
- /*
- * We can't provide enable/disable callback as we can't perform the same
- * in atomic context. Since the clock framework provides standard API
- * clk_prepare_enable that helps cases using clk_enable in non-atomic
- * context, it should be fine providing prepare/unprepare.
- */
.prepare = scmi_clk_enable,
.unprepare = scmi_clk_disable,
};
-static int scmi_clk_ops_init(struct device *dev, struct scmi_clk *sclk)
+static const struct clk_ops scmi_atomic_clk_ops = {
+ .recalc_rate = scmi_clk_recalc_rate,
+ .round_rate = scmi_clk_round_rate,
+ .set_rate = scmi_clk_set_rate,
+ .enable = scmi_clk_atomic_enable,
+ .disable = scmi_clk_atomic_disable,
+};
+
+static int scmi_clk_ops_init(struct device *dev, struct scmi_clk *sclk,
+ const struct clk_ops *scmi_ops)
{
int ret;
+ unsigned long min_rate, max_rate;
+
struct clk_init_data init = {
.flags = CLK_GET_RATE_NOCACHE,
.num_parents = 0,
- .ops = &scmi_clk_ops,
+ .ops = scmi_ops,
.name = sclk->info->name,
};
sclk->hw.init = &init;
ret = devm_clk_hw_register(dev, &sclk->hw);
- if (!ret)
- clk_hw_set_rate_range(&sclk->hw, sclk->info->range.min_rate,
- sclk->info->range.max_rate);
+ if (ret)
+ return ret;
+
+ if (sclk->info->rate_discrete) {
+ int num_rates = sclk->info->list.num_rates;
+
+ if (num_rates <= 0)
+ return -EINVAL;
+
+ min_rate = sclk->info->list.rates[0];
+ max_rate = sclk->info->list.rates[num_rates - 1];
+ } else {
+ min_rate = sclk->info->range.min_rate;
+ max_rate = sclk->info->range.max_rate;
+ }
+
+ clk_hw_set_rate_range(&sclk->hw, min_rate, max_rate);
return ret;
}
static int scmi_clocks_probe(struct scmi_device *sdev)
{
int idx, count, err;
+ unsigned int atomic_threshold;
+ bool is_atomic;
struct clk_hw **hws;
struct clk_hw_onecell_data *clk_data;
struct device *dev = &sdev->dev;
struct device_node *np = dev->of_node;
const struct scmi_handle *handle = sdev->handle;
+ struct scmi_protocol_handle *ph;
- if (!handle || !handle->clk_ops)
+ if (!handle)
return -ENODEV;
- count = handle->clk_ops->count_get(handle);
+ scmi_proto_clk_ops =
+ handle->devm_protocol_get(sdev, SCMI_PROTOCOL_CLOCK, &ph);
+ if (IS_ERR(scmi_proto_clk_ops))
+ return PTR_ERR(scmi_proto_clk_ops);
+
+ count = scmi_proto_clk_ops->count_get(ph);
if (count < 0) {
dev_err(dev, "%pOFn: invalid clock output count\n", np);
return -EINVAL;
@@ -144,29 +200,46 @@ static int scmi_clocks_probe(struct scmi_device *sdev)
clk_data->num = count;
hws = clk_data->hws;
+ is_atomic = handle->is_transport_atomic(handle, &atomic_threshold);
+
for (idx = 0; idx < count; idx++) {
struct scmi_clk *sclk;
+ const struct clk_ops *scmi_ops;
sclk = devm_kzalloc(dev, sizeof(*sclk), GFP_KERNEL);
if (!sclk)
return -ENOMEM;
- sclk->info = handle->clk_ops->info_get(handle, idx);
+ sclk->info = scmi_proto_clk_ops->info_get(ph, idx);
if (!sclk->info) {
dev_dbg(dev, "invalid clock info for idx %d\n", idx);
continue;
}
sclk->id = idx;
- sclk->handle = handle;
-
- err = scmi_clk_ops_init(dev, sclk);
+ sclk->ph = ph;
+
+ /*
+ * Note that when transport is atomic but SCMI protocol did not
+ * specify (or support) an enable_latency associated with a
+ * clock, we default to use atomic operations mode.
+ */
+ if (is_atomic &&
+ sclk->info->enable_latency <= atomic_threshold)
+ scmi_ops = &scmi_atomic_clk_ops;
+ else
+ scmi_ops = &scmi_clk_ops;
+
+ err = scmi_clk_ops_init(dev, sclk, scmi_ops);
if (err) {
dev_err(dev, "failed to register clock %d\n", idx);
devm_kfree(dev, sclk);
hws[idx] = NULL;
} else {
- dev_dbg(dev, "Registered clock:%s\n", sclk->info->name);
+ dev_dbg(dev, "Registered clock:%s%s\n",
+ sclk->info->name,
+ scmi_ops == &scmi_atomic_clk_ops ?
+ " (atomic ops)" : "");
hws[idx] = &sclk->hw;
}
}
@@ -176,7 +249,7 @@ static int scmi_clocks_probe(struct scmi_device *sdev)
}
static const struct scmi_device_id scmi_id_table[] = {
- { SCMI_PROTOCOL_CLOCK },
+ { SCMI_PROTOCOL_CLOCK, "clocks" },
{ },
};
MODULE_DEVICE_TABLE(scmi, scmi_id_table);
generated by cgit v1.2.3 (git 2.25.1) at 2024-04-24 11:27:15 +0000