Re: [PATCH 1/5] mfd: mc13xxx: add device tree probe support

On Tue, Nov 29, 2011 at 01:53:31PM +0530, Rajendra Nayak wrote:

[]...

quoted

+};
+MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids);
+
 static int mc13xxx_probe(struct spi_device *spi)
 {
+	struct device_node *np = spi->dev.of_node;
+	const struct of_device_id *of_id;
+	struct spi_driver *sdrv = to_spi_driver(spi->dev.driver);
 	struct mc13xxx *mc13xxx;
 	struct mc13xxx_platform_data *pdata = dev_get_platdata(&spi->dev);
 	enum mc13xxx_id id;
 	int ret;

-	if (!pdata) {
-		dev_err(&spi->dev, "invalid platform data\n");
-		return -EINVAL;
-	}
+	of_id = of_match_device(mc13xxx_dt_ids,&spi->dev);
+	if (of_id)
+		sdrv->id_table =&mc13xxx_device_id[(enum mc13xxx_id) of_id->data];

 	mc13xxx = kzalloc(sizeof(*mc13xxx), GFP_KERNEL);
 	if (!mc13xxx)

@@ -735,6 +787,15 @@ static int mc13xxx_probe(struct spi_device *spi)
 	if (ret)
 		goto err_mask;

+	mc13xxx->irq_gpio = of_get_named_gpio(np, "mc13xxx-irq-gpios", 0);
+	if (gpio_is_valid(mc13xxx->irq_gpio)) {
+		ret = gpio_request_one(mc13xxx->irq_gpio, GPIOF_IN,
+				       "mc13xxx-irq");
+		if (ret)
+			goto err_mask;
+		spi->irq = gpio_to_irq(mc13xxx->irq_gpio);

This seems wrong, because its adding information about the irq actually
being a gpio within the driver (which was otherwise hidden by the board
files doing a gpio_to_irq()). What happens if on some device this is
actually hooked to an irq line instead of a gpio?
There should be a better way to do this using Device tree.

Indeed.  I should have 'interrupt-parent' and 'interrupts' encoded as
below, so that 'spi->irq = irq_of_parse_and_map(nc, 0);' in of_spi.c
can get the irq set up properly.

pmic: mc13892@0 {
	#address-cells = <1>;
	#size-cells = <0>;
	compatible = "fsl,mc13892";
	spi-max-frequency = <6000000>;
	reg = <0>;
	interrupt-parent = <&gpio0>;
	interrupts = <8>;
};

Thanks for catching this.

-- 
Regards,
Shawn