[PATCH v5 08/13] clk: scmi: Support atomic enable/disable API
From: Cristian Marussi <cristian.marussi@arm.com>
Date: 2021-09-23 14:58:53
Also in:
lkml
Subsystem:
common clk framework, system control & power/management interface (scpi/scmi) message protocol drivers, the rest · Maintainers:
Michael Turquette, Stephen Boyd, Sudeep Holla, Linus Torvalds
Support enable/disable clk_ops instead of prepare/unprepare when the underlying SCMI transport is configured to support atomic transactions for synchronous commands. Reviewed-by: Florian Fainelli <f.fainelli@gmail.com> 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..21480b6dd763 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 SCMI 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
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel