From: Yang Xiwen <forbidden405@outlook.com>
To: Rob Herring <robh+dt@kernel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Conor Dooley <conor+dt@kernel.org>,
Geert Uytterhoeven <geert+renesas@glider.be>,
Philipp Zabel <p.zabel@pengutronix.de>
Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
Yang Xiwen <forbidden405@outlook.com>
Subject: [PATCH v2 2/2] drivers: bus: simple-pm-bus: Get and deassert resets exclusively
Date: Fri, 23 Feb 2024 18:10:20 +0800 [thread overview]
Message-ID: <20240223-b4-bus-v2-2-da8ba83c1a5f@outlook.com> (raw)
In-Reply-To: <20240223-b4-bus-v2-0-da8ba83c1a5f@outlook.com>
Simple Power-Managed bus controller may need functional reset(s)
to be deasserted before child devices connected to the bus can be
accessed. Get the reset(s) as an array and assert/deassert the
reset(s) when the bus is being power managed.
One example is that HiSilicon USB2 INNO PHY test bus needs to deassert
the reset to the bus before accessing its registers.
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Yang Xiwen <forbidden405@outlook.com>
---
drivers/bus/simple-pm-bus.c | 16 ++++++++++++++--
1 file changed, 14 insertions(+), 2 deletions(-)
diff --git a/drivers/bus/simple-pm-bus.c b/drivers/bus/simple-pm-bus.c
index 50870c827889..f2e98eac0bb4 100644
--- a/drivers/bus/simple-pm-bus.c
+++ b/drivers/bus/simple-pm-bus.c
@@ -16,15 +16,17 @@
#include <linux/of_platform.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
+#include <linux/reset.h>
struct simple_pm_bus {
struct clk_bulk_data *clks;
+ struct reset_control *rsts;
int num_clks;
};
static int simple_pm_bus_probe(struct platform_device *pdev)
{
- const struct device *dev = &pdev->dev;
+ struct device *dev = &pdev->dev;
const struct of_dev_auxdata *lookup = dev_get_platdata(dev);
struct device_node *np = dev->of_node;
const struct of_device_id *match;
@@ -62,6 +64,10 @@ static int simple_pm_bus_probe(struct platform_device *pdev)
if (bus->num_clks < 0)
return dev_err_probe(&pdev->dev, bus->num_clks, "failed to get clocks\n");
+ bus->rsts = devm_reset_control_array_get_optional_exclusive(dev);
+ if (IS_ERR(bus->rsts))
+ return dev_err_probe(&pdev->dev, PTR_ERR(bus->rsts), "failed to get resets\n");
+
dev_set_drvdata(&pdev->dev, bus);
dev_dbg(&pdev->dev, "%s\n", __func__);
@@ -92,7 +98,7 @@ static int simple_pm_bus_runtime_suspend(struct device *dev)
clk_bulk_disable_unprepare(bus->num_clks, bus->clks);
- return 0;
+ return reset_control_assert(bus->rsts);
}
static int simple_pm_bus_runtime_resume(struct device *dev)
@@ -106,6 +112,12 @@ static int simple_pm_bus_runtime_resume(struct device *dev)
return ret;
}
+ ret = reset_control_deassert(bus->rsts);
+ if (ret) {
+ dev_err(dev, "failed to deassert resets: %d\n", ret);
+ return ret;
+ }
+
return 0;
}
--
2.43.0
prev parent reply other threads:[~2024-02-23 10:10 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-23 10:10 [PATCH v2 0/2] simple-pm-bus: deassert resets if possible Yang Xiwen
2024-02-23 10:10 ` [PATCH v2 1/2] dt-bindings: simple-pm-bus: Add optional resets Yang Xiwen
2024-02-23 10:10 ` Yang Xiwen [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20240223-b4-bus-v2-2-da8ba83c1a5f@outlook.com \
--to=forbidden405@outlook.com \
--cc=conor+dt@kernel.org \
--cc=devicetree@vger.kernel.org \
--cc=geert+renesas@glider.be \
--cc=krzysztof.kozlowski+dt@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=p.zabel@pengutronix.de \
--cc=robh+dt@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).