linux-kernel - [PATCH v5 4/5] mfd: tqmx86: make IRQ setup errors non-fatal

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Message-ID: <95e7deca3451f2fb19b2c8253e9d19117bbdd06c.1729509613.git.matthias.schiffer@ew.tq-group.com>
Date: Mon, 21 Oct 2024 13:34:26 +0200
From: Matthias Schiffer <matthias.schiffer@...tq-group.com>
To: Lee Jones <lee@...nel.org>
Cc: linux@...tq-group.com,
	linux-kernel@...r.kernel.org,
	Matthias Schiffer <matthias.schiffer@...tq-group.com>
Subject: [PATCH v5 4/5] mfd: tqmx86: make IRQ setup errors non-fatal

GPIO IRQ setup can fail either because an invalid IRQ was passed as a
parameter, or because the GPIO controller does not support interrupts.
Neither is severe enough to stop the whole probe; simply disable IRQ
support in the GPIO resource when setup fails.

The code is made a bit more robust by introduing a define for the index
of the IRQ resource in the resource list instead of assuming that it is
at index 0.

Signed-off-by: Matthias Schiffer <matthias.schiffer@...tq-group.com>
---

v2: no changes (was patch 3/4)
v3: replace IRQ 0 resource with an empty placeholder to simplify error handling
v4: no changes
v5: move placeholder to the end of the resource array, use define for index

 drivers/mfd/tqmx86.c | 19 +++++++------------
 1 file changed, 7 insertions(+), 12 deletions(-)

diff --git a/drivers/mfd/tqmx86.c b/drivers/mfd/tqmx86.c
index 8aa448a67c9a5..1fd2212bf492c 100644
--- a/drivers/mfd/tqmx86.c
+++ b/drivers/mfd/tqmx86.c
@@ -60,6 +60,9 @@ static uint gpio_irq;
 module_param(gpio_irq, uint, 0);
 MODULE_PARM_DESC(gpio_irq, "GPIO IRQ number (valid parameters: 7, 9, 12)");
 
+/* Index of IRQ placeholder in resource list */
+#define TQMX86_IRQ_GPIO 1
+
 static const struct resource tqmx_i2c_soft_resources[] = {
 	DEFINE_RES_IO(TQMX86_IOBASE_I2C, TQMX86_IOSIZE_I2C),
 };
@@ -68,13 +71,10 @@ static const struct resource tqmx_watchdog_resources[] = {
 	DEFINE_RES_IO(TQMX86_IOBASE_WATCHDOG, TQMX86_IOSIZE_WATCHDOG),
 };
 
-/*
- * The IRQ resource must be first, since it is updated with the
- * configured IRQ in the probe function.
- */
 static struct resource tqmx_gpio_resources[] = {
-	DEFINE_RES_IRQ(0),
 	DEFINE_RES_IO(TQMX86_IOBASE_GPIO, TQMX86_IOSIZE_GPIO),
+	/* Placeholder for IRQ resource - filled in by the probe function */
+	[TQMX86_IRQ_GPIO] = {},
 };
 
 static struct i2c_board_info tqmx86_i2c_devices[] = {
@@ -255,13 +255,8 @@ static int tqmx86_probe(struct platform_device *pdev)
 	if (gpio_irq) {
 		err = tqmx86_setup_irq(dev, "GPIO", gpio_irq, io_base,
 				       TQMX86_REG_IO_EXT_INT_GPIO_SHIFT);
-		if (err)
-			return err;
-
-		/* Assumes the IRQ resource is first. */
-		tqmx_gpio_resources[0].start = gpio_irq;
-	} else {
-		tqmx_gpio_resources[0].flags = 0;
+		if (!err)
+			tqmx_gpio_resources[TQMX86_IRQ_GPIO] = DEFINE_RES_IRQ(gpio_irq);
 	}
 
 	ocores_platform_data.clock_khz = tqmx86_board_id_to_clk_rate(dev, board_id);
-- 
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