[PATCH v3 3/3] pinctrl: renesas: rza2: Add lock around pinctrl_generic{{add,remove}_group,{add,remove}_function}

From: Biju Das <biju.das.jz@bp.renesas.com>
To: Linus Walleij <linus.walleij@linaro.org>
Cc: Biju Das <biju.das.jz@bp.renesas.com>,
	Geert Uytterhoeven <geert+renesas@glider.be>,
	Chris Brandt <chris.brandt@renesas.com>,
	Jacopo Mondi <jacopo+renesas@jmondi.org>,
	linux-renesas-soc@vger.kernel.org, linux-gpio@vger.kernel.org,
	Fabrizio Castro <fabrizio.castro.jz@renesas.com>,
	Prabhakar Mahadev Lad <prabhakar.mahadev-lad.rj@bp.renesas.com>,
	stable@kernel.org
Subject: [PATCH v3 3/3] pinctrl: renesas: rza2: Add lock around pinctrl_generic{{add,remove}_group,{add,remove}_function}
Date: Tue, 15 Aug 2023 14:15:58 +0100	[thread overview]
Message-ID: <20230815131558.33787-4-biju.das.jz@bp.renesas.com> (raw)
In-Reply-To: <20230815131558.33787-1-biju.das.jz@bp.renesas.com>

The pinctrl group and function creation/remove calls expect
caller to take care of locking. Add lock around these functions.

Fixes: b59d0e782706 ("pinctrl: Add RZ/A2 pin and gpio controller")
Cc: stable@kernel.org
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v2->v3:
 * Added unlock_and_done label for lock error path.
v1->v2:
 * No change.
---
 drivers/pinctrl/renesas/pinctrl-rza2.c | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/drivers/pinctrl/renesas/pinctrl-rza2.c b/drivers/pinctrl/renesas/pinctrl-rza2.c
index 0b454a31c4bd..cf0f130a3720 100644
--- a/drivers/pinctrl/renesas/pinctrl-rza2.c
+++ b/drivers/pinctrl/renesas/pinctrl-rza2.c
@@ -14,6 +14,7 @@
 #include <linux/gpio/driver.h>
 #include <linux/io.h>
 #include <linux/module.h>
+#include <linux/mutex.h>
 #include <linux/of.h>
 #include <linux/pinctrl/pinmux.h>
 #include <linux/platform_device.h>
@@ -47,6 +48,7 @@ struct rza2_pinctrl_priv {
 	struct pinctrl_dev *pctl;
 	struct pinctrl_gpio_range gpio_range;
 	int npins;
+	struct mutex mutex; /* serialize adding groups and functions */
 };
 
 #define RZA2_PDR(port)		(0x0000 + (port) * 2)	/* Direction 16-bit */
@@ -359,10 +361,13 @@ static int rza2_dt_node_to_map(struct pinctrl_dev *pctldev,
 		psel_val[i] = MUX_FUNC(value);
 	}
 
+	mutex_lock(&priv->mutex);
 	/* Register a single pin group listing all the pins we read from DT */
 	gsel = pinctrl_generic_add_group(pctldev, np->name, pins, npins, NULL);
-	if (gsel < 0)
-		return gsel;
+	if (gsel < 0) {
+		ret = gsel;
+		goto unlock_and_done;
+	}
 
 	/*
 	 * Register a single group function where the 'data' is an array PSEL
@@ -390,6 +395,7 @@ static int rza2_dt_node_to_map(struct pinctrl_dev *pctldev,
 	(*map)->data.mux.group = np->name;
 	(*map)->data.mux.function = np->name;
 	*num_maps = 1;
+	mutex_unlock(&priv->mutex);
 
 	return 0;
 
@@ -399,6 +405,9 @@ static int rza2_dt_node_to_map(struct pinctrl_dev *pctldev,
 remove_group:
 	pinctrl_generic_remove_group(pctldev, gsel);
 
+unlock_and_done:
+	mutex_unlock(&priv->mutex);
+
 	dev_err(priv->dev, "Unable to parse DT node %s\n", np->name);
 
 	return ret;
@@ -474,6 +483,8 @@ static int rza2_pinctrl_probe(struct platform_device *pdev)
 	if (IS_ERR(priv->base))
 		return PTR_ERR(priv->base);
 
+	mutex_init(&priv->mutex);
+
 	platform_set_drvdata(pdev, priv);
 
 	priv->npins = (int)(uintptr_t)of_device_get_match_data(&pdev->dev) *
-- 
2.25.1

