drm/mediatek: Add missing IS_ERR check for ovl_adaptor platform devicegrafted

platform_device_register_data() can fail and return an ERR_PTR, but the
return value is used without checking, leading to an invalid pointer
being stored in ddp_comp[].dev and passed to component_match_add() and
mtk_ddp_comp_init(), which could result in a kernel crash.

Add an IS_ERR() check to jump to the error handling path on failure.

Fixes: 0d9eee9118b7 ("drm/mediatek: Add drm ovl_adaptor sub driver for MT8195")
Cc: stable@vger.kernel.org
Signed-off-by: Haojie Li <lihaojie@kylinos.cn>
Reviewed-by: CK Hu <ck.hu@mediatek.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20260825100845.438893-1-lihaojie@kylinos.cn/
Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

1 files changed, 136 insertions, 0 deletions

diff --git a/drivers/reset/reset-pistachio.c b/drivers/reset/reset-pistachio.c
new file mode 100644
index 000000000..151ceeb42
--- /dev/null
+++ b/drivers/reset/reset-pistachio.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Pistachio SoC Reset Controller driver
+ *
+ * Copyright (C) 2015 Imagination Technologies Ltd.
+ *
+ * Author: Damien Horsley <Damien.Horsley@imgtec.com>
+ */
+
+#include <linux/init.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+#include <linux/mfd/syscon.h>
+
+#include <dt-bindings/reset/pistachio-resets.h>
+
+#define	PISTACHIO_SOFT_RESET		0
+
+struct pistachio_reset_data {
+	struct reset_controller_dev	rcdev;
+	struct regmap			*periph_regs;
+};
+
+static inline int pistachio_reset_shift(unsigned long id)
+{
+	switch (id) {
+	case PISTACHIO_RESET_I2C0:
+	case PISTACHIO_RESET_I2C1:
+	case PISTACHIO_RESET_I2C2:
+	case PISTACHIO_RESET_I2C3:
+	case PISTACHIO_RESET_I2S_IN:
+	case PISTACHIO_RESET_PRL_OUT:
+	case PISTACHIO_RESET_SPDIF_OUT:
+	case PISTACHIO_RESET_SPI:
+	case PISTACHIO_RESET_PWM_PDM:
+	case PISTACHIO_RESET_UART0:
+	case PISTACHIO_RESET_UART1:
+	case PISTACHIO_RESET_QSPI:
+	case PISTACHIO_RESET_MDC:
+	case PISTACHIO_RESET_SDHOST:
+	case PISTACHIO_RESET_ETHERNET:
+	case PISTACHIO_RESET_IR:
+	case PISTACHIO_RESET_HASH:
+	case PISTACHIO_RESET_TIMER:
+		return id;
+	case PISTACHIO_RESET_I2S_OUT:
+	case PISTACHIO_RESET_SPDIF_IN:
+	case PISTACHIO_RESET_EVT:
+		return id + 6;
+	case PISTACHIO_RESET_USB_H:
+	case PISTACHIO_RESET_USB_PR:
+	case PISTACHIO_RESET_USB_PHY_PR:
+	case PISTACHIO_RESET_USB_PHY_PON:
+		return id + 7;
+	default:
+		return -EINVAL;
+	}
+}
+
+static int pistachio_reset_assert(struct reset_controller_dev *rcdev,
+				  unsigned long id)
+{
+	struct pistachio_reset_data *rd;
+	u32 mask;
+	int shift;
+
+	rd = container_of(rcdev, struct pistachio_reset_data, rcdev);
+	shift = pistachio_reset_shift(id);
+	if (shift < 0)
+		return shift;
+	mask = BIT(shift);
+
+	return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET,
+				  mask, mask);
+}
+
+static int pistachio_reset_deassert(struct reset_controller_dev *rcdev,
+				    unsigned long id)
+{
+	struct pistachio_reset_data *rd;
+	u32 mask;
+	int shift;
+
+	rd = container_of(rcdev, struct pistachio_reset_data, rcdev);
+	shift = pistachio_reset_shift(id);
+	if (shift < 0)
+		return shift;
+	mask = BIT(shift);
+
+	return regmap_update_bits(rd->periph_regs, PISTACHIO_SOFT_RESET,
+				  mask, 0);
+}
+
+static const struct reset_control_ops pistachio_reset_ops = {
+	.assert		= pistachio_reset_assert,
+	.deassert	= pistachio_reset_deassert,
+};
+
+static int pistachio_reset_probe(struct platform_device *pdev)
+{
+	struct pistachio_reset_data *rd;
+	struct device *dev = &pdev->dev;
+	struct device_node *np = pdev->dev.of_node;
+
+	rd = devm_kzalloc(dev, sizeof(*rd), GFP_KERNEL);
+	if (!rd)
+		return -ENOMEM;
+
+	rd->periph_regs = syscon_node_to_regmap(np->parent);
+	if (IS_ERR(rd->periph_regs))
+		return PTR_ERR(rd->periph_regs);
+
+	rd->rcdev.owner = THIS_MODULE;
+	rd->rcdev.nr_resets = PISTACHIO_RESET_MAX + 1;
+	rd->rcdev.ops = &pistachio_reset_ops;
+	rd->rcdev.of_node = np;
+
+	return devm_reset_controller_register(dev, &rd->rcdev);
+}
+
+static const struct of_device_id pistachio_reset_dt_ids[] = {
+	 { .compatible = "img,pistachio-reset", },
+	 { /* sentinel */ },
+};
+
+static struct platform_driver pistachio_reset_driver = {
+	.probe	= pistachio_reset_probe,
+	.driver = {
+		.name		= "pistachio-reset",
+		.of_match_table	= pistachio_reset_dt_ids,
+	},
+};
+builtin_platform_driver(pistachio_reset_driver);