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From: Cristian Marussi <cristian.marussi@arm.com>
To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Cc: sudeep.holla@arm.com, james.quinlan@broadcom.com,
	Jonathan.Cameron@Huawei.com, f.fainelli@gmail.com,
	etienne.carriere@linaro.org, vincent.guittot@linaro.org,
	souvik.chakravarty@arm.com, cristian.marussi@arm.com
Subject: [PATCH v4 07/12] clk: scmi: Support atomic enable/disable API
Date: Tue, 24 Aug 2021 14:59:36 +0100	[thread overview]
Message-ID: <20210824135941.38656-8-cristian.marussi@arm.com> (raw)
In-Reply-To: <20210824135941.38656-1-cristian.marussi@arm.com>

Support enable/disable clk_ops instead of prepare/unprepare when the
underlying SCMI transport is configured to support atomic transactions for
synchronous commands.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/clk/clk-scmi.c | 44 +++++++++++++++++++++++++++++++++---------
 1 file changed, 35 insertions(+), 9 deletions(-)

diff --git a/drivers/clk/clk-scmi.c b/drivers/clk/clk-scmi.c
index 1e357d364ca2..a07117d5e5bd 100644
--- a/drivers/clk/clk-scmi.c
+++ b/drivers/clk/clk-scmi.c
@@ -88,21 +88,42 @@ static void scmi_clk_disable(struct clk_hw *hw)
 	scmi_proto_clk_ops->disable(clk->ph, clk->id);
 }
 
+/*
+ * We can provide enable/disable atomic callbacks only if the underlying SCMI
+ * transport for this SCMI instance is configured to handle synchronous commands
+ * in an atomic manner.
+ *
+ * When no SCMI atomic transport support is available we instead provide the
+ * prepare/unprepare API, as allowed by the clock framework where atomic calls
+ * are not available.
+ *
+ * Note that the provided clk_ops implementations are the same in both cases,
+ * using indeed the same underlying SCMI clock_protocol operations, it's just
+ * that they are assured to act in an atomic manner or not depending on the
+ * actual underlying SCMI transport configuration.
+ *
+ * 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_enable,
+	.disable = scmi_clk_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;
@@ -110,7 +131,7 @@ static int scmi_clk_ops_init(struct device *dev, struct scmi_clk *sclk)
 	struct clk_init_data init = {
 		.flags = CLK_GET_RATE_NOCACHE,
 		.num_parents = 0,
-		.ops = &scmi_clk_ops,
+		.ops = scmi_ops,
 		.name = sclk->info->name,
 	};
 
@@ -145,6 +166,7 @@ static int scmi_clocks_probe(struct scmi_device *sdev)
 	struct device_node *np = dev->of_node;
 	const struct scmi_handle *handle = sdev->handle;
 	struct scmi_protocol_handle *ph;
+	bool is_atomic;
 
 	if (!handle)
 		return -ENODEV;
@@ -168,6 +190,8 @@ static int scmi_clocks_probe(struct scmi_device *sdev)
 	clk_data->num = count;
 	hws = clk_data->hws;
 
+	is_atomic = handle->is_transport_atomic(handle);
+
 	for (idx = 0; idx < count; idx++) {
 		struct scmi_clk *sclk;
 
@@ -184,7 +208,9 @@ static int scmi_clocks_probe(struct scmi_device *sdev)
 		sclk->id = idx;
 		sclk->ph = ph;
 
-		err = scmi_clk_ops_init(dev, sclk);
+		err = scmi_clk_ops_init(dev, sclk,
+					is_atomic ? &scmi_atomic_clk_ops :
+					&scmi_clk_ops);
 		if (err) {
 			dev_err(dev, "failed to register clock %d\n", idx);
 			devm_kfree(dev, sclk);
-- 
2.17.1


  parent reply	other threads:[~2021-08-24 14:00 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-08-24 13:59 [PATCH v4 0/12] Introduce atomic support for SCMI transports Cristian Marussi
2021-08-24 13:59 ` [PATCH v4 01/12] firmware: arm_scmi: Perform earlier cinfo lookup call in do_xfer Cristian Marussi
2021-08-25 16:28   ` Florian Fainelli
2021-08-24 13:59 ` [PATCH v4 02/12] firmware: arm_scmi: Add configurable polling mode for transports Cristian Marussi
2021-08-25 16:29   ` Florian Fainelli
2021-08-24 13:59 ` [PATCH v4 03/12] firmware: arm_scmi: Add support for atomic transports Cristian Marussi
2021-08-25 16:18   ` Jim Quinlan
2021-08-25 17:50     ` Cristian Marussi
2021-08-24 13:59 ` [PATCH v4 04/12] include: trace: Add new scmi_xfer_response_wait event Cristian Marussi
2021-08-25 16:30   ` Florian Fainelli
2021-08-24 13:59 ` [PATCH v4 05/12] firmware: arm_scmi: Use new trace event scmi_xfer_response_wait Cristian Marussi
2021-08-25 16:31   ` Florian Fainelli
2021-08-25 17:52     ` Cristian Marussi
2021-08-24 13:59 ` [PATCH v4 06/12] firmware: arm_scmi: Add is_transport_atomic() handle method Cristian Marussi
2021-08-25 16:32   ` Florian Fainelli
2021-08-24 13:59 ` Cristian Marussi [this message]
2021-08-25 16:33   ` [PATCH v4 07/12] clk: scmi: Support atomic enable/disable API Florian Fainelli
2021-08-24 13:59 ` [PATCH v4 08/12] firmware: arm_scmi: Declare virtio transport .atomic_capable Cristian Marussi
2021-08-24 13:59 ` [PATCH v4 09/12] [RFC] firmware: arm_scmi: Make smc transport use common completions Cristian Marussi
2021-08-25 16:35   ` Florian Fainelli
2021-08-24 13:59 ` [PATCH v4 10/12] [RFC] firmware: arm_scmi: Make smc transport atomic Cristian Marussi
2021-08-24 13:59 ` [PATCH v4 11/12] [RFC] firmware: arm_scmi: Add sync_cmds_atomic_replies transport flag Cristian Marussi
2021-08-25 16:38   ` Florian Fainelli
2021-08-25 17:17     ` Jim Quinlan
2021-08-25 18:49       ` Cristian Marussi
2021-08-26 18:29         ` Jim Quinlan
2021-08-31  5:56           ` Cristian Marussi
2021-09-23 15:03           ` Cristian Marussi
2021-10-04 17:50             ` Jim Quinlan
2021-10-04 18:00               ` Cristian Marussi
2021-08-24 13:59 ` [PATCH v4 12/12] [RFC] firmware: arm_scmi: Make smc support atomic commands replies Cristian Marussi

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