linux-kernel - [PATCH v2 3/4] reset: socfpga: add empty driver allowing consumers to probe

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Tue,  5 Oct 2021 16:37:47 +0200
From:   Paweł Anikiel <pan@...ihalf.com>
To:     jarkko.nikula@...ux.intel.com, andriy.shevchenko@...ux.intel.com,
        mika.westerberg@...ux.intel.com, robh+dt@...nel.org,
        p.zabel@...gutronix.de, arnd@...db.de, olof@...om.net,
        soc@...nel.org, dinguyen@...nel.org, p.yadav@...com,
        Tudor.Ambarus@...rochip.com
Cc:     linux-i2c@...r.kernel.org, linux-kernel@...r.kernel.org,
        alexandre.belloni@...tlin.com, sre@...nel.org,
        thunder.leizhen@...wei.com, Jonathan.Cameron@...wei.com,
        devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        ka@...ihalf.com, tn@...ihalf.com, jam@...ihalf.com,
        amstan@...gle.com,
        Paweł Anikiel <pan@...ihalf.com>
Subject: [PATCH v2 3/4] reset: socfpga: add empty driver allowing consumers to probe

The early reset driver doesn't ever probe, which causes consuming
devices to be unable to probe. Add an empty driver to set this device
as available, allowing consumers to probe.

Signed-off-by: Paweł Anikiel <pan@...ihalf.com>
---
 drivers/reset/reset-socfpga.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/reset/reset-socfpga.c b/drivers/reset/reset-socfpga.c
index 2a72f861f798..8c6492e5693c 100644
--- a/drivers/reset/reset-socfpga.c
+++ b/drivers/reset/reset-socfpga.c
@@ -92,3 +92,29 @@ void __init socfpga_reset_init(void)
 	for_each_matching_node(np, socfpga_early_reset_dt_ids)
 		a10_reset_init(np);
 }
+
+/*
+ * The early driver is problematic, because it doesn't register
+ * itself as a driver. This causes certain device links to prevent
+ * consumer devices from probing. The hacky solution is to register
+ * an empty driver, whose only job is to attach itself to the reset
+ * manager and call probe.
+ */
+static const struct of_device_id socfpga_reset_dt_ids[] = {
+	{ .compatible = "altr,rst-mgr", },
+	{ /* sentinel */ },
+};
+
+static int reset_simple_probe(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static struct platform_driver reset_socfpga_driver = {
+	.probe	= reset_simple_probe,
+	.driver = {
+		.name		= "socfpga-reset",
+		.of_match_table	= socfpga_reset_dt_ids,
+	},
+};
+builtin_platform_driver(reset_socfpga_driver);
-- 
2.25.1