ARM/gpio: Push OMAP2 quirk down into TWL4030 driver

The TWL4030 GPIO driver has a custom platform data .set_up()
callback to call back into the platform and do misc stuff such
as hog and export a GPIO for WLAN PWR on a specific OMAP3 board.

Avoid all the kludgery in the platform data and the boardfile
and just put the quirks right into the driver. Make it
conditional on OMAP3.

I think the exported GPIO is used by some kind of userspace
so ordinary DTS hogs will probably not work.

Fixes: 92bf78b ("gpio: omap: use dynamic allocation of base")
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Author: Linus Walleij

arch/arm/mach-omap2/omap_device.c

@@ -244,7 +244,6 @@ static int _omap_device_notifier_call(struct notifier_block *nb,
 	case BUS_NOTIFY_ADD_DEVICE:
 		if (pdev->dev.of_node)
 			omap_device_build_from_dt(pdev);
-		omap_auxdata_legacy_init(dev);
 		fallthrough;
 	default:
 		od = to_omap_device(pdev);

arch/arm/mach-omap2/pdata-quirks.c

@@ -6,6 +6,7 @@
  */
 #include <linux/clk.h>
 #include <linux/davinci_emac.h>
+#include <linux/gpio/machine.h>
 #include <linux/gpio/consumer.h>
 #include <linux/gpio.h>
 #include <linux/init.h>
@@ -41,7 +42,6 @@ struct pdata_init {
 };
 
 static struct of_dev_auxdata omap_auxdata_lookup[];
-static struct twl4030_gpio_platform_data twl_gpio_auxdata;
 
 #ifdef CONFIG_MACH_NOKIA_N8X0
 static void __init omap2420_n8x0_legacy_init(void)
@@ -98,22 +98,6 @@ static struct iommu_platform_data omap3_iommu_isp_pdata = {
 };
 #endif
 
-static int omap3_sbc_t3730_twl_callback(struct device *dev,
-					   unsigned gpio,
-					   unsigned ngpio)
-{
-	int res;
-
-	res = gpio_request_one(gpio + 2, GPIOF_OUT_INIT_HIGH,
-			       "wlan pwr");
-	if (res)
-		return res;
-
-	gpiod_export(gpio_to_desc(gpio), 0);
-
-	return 0;
-}
-
 static void __init omap3_sbc_t3x_usb_hub_init(int gpio, char *hub_name)
 {
 	int err = gpio_request_one(gpio, GPIOF_OUT_INIT_LOW, hub_name);
@@ -131,11 +115,6 @@ static void __init omap3_sbc_t3x_usb_hub_init(int gpio, char *hub_name)
 	msleep(1);
 }
 
-static void __init omap3_sbc_t3730_twl_init(void)
-{
-	twl_gpio_auxdata.setup = omap3_sbc_t3730_twl_callback;
-}
-
 static void __init omap3_sbc_t3730_legacy_init(void)
 {
 	omap3_sbc_t3x_usb_hub_init(167, "sb-t35 usb hub");
@@ -393,21 +372,6 @@ static struct ti_prm_platform_data ti_prm_pdata = {
 	.clkdm_lookup = clkdm_lookup,
 };
 
-/*
- * GPIOs for TWL are initialized by the I2C bus and need custom
- * handing until DSS has device tree bindings.
- */
-void omap_auxdata_legacy_init(struct device *dev)
-{
-	if (dev->platform_data)
-		return;
-
-	if (strcmp("twl4030-gpio", dev_name(dev)))
-		return;
-
-	dev->platform_data = &twl_gpio_auxdata;
-}
-
 #if defined(CONFIG_ARCH_OMAP3) && IS_ENABLED(CONFIG_SND_SOC_OMAP_MCBSP)
 static struct omap_mcbsp_platform_data mcbsp_pdata;
 static void __init omap3_mcbsp_init(void)
@@ -427,9 +391,6 @@ static struct pdata_init auxdata_quirks[] __initdata = {
 	{ "nokia,n800", omap2420_n8x0_legacy_init, },
 	{ "nokia,n810", omap2420_n8x0_legacy_init, },
 	{ "nokia,n810-wimax", omap2420_n8x0_legacy_init, },
-#endif
-#ifdef CONFIG_ARCH_OMAP3
-	{ "compulab,omap3-sbc-t3730", omap3_sbc_t3730_twl_init, },
 #endif
 	{ /* sentinel */ },
 };

drivers/gpio/gpio-twl4030.c

@@ -17,7 +17,9 @@
 #include <linux/interrupt.h>
 #include <linux/kthread.h>
 #include <linux/irq.h>
+#include <linux/gpio/machine.h>
 #include <linux/gpio/driver.h>
+#include <linux/gpio/consumer.h>
 #include <linux/platform_device.h>
 #include <linux/of.h>
 #include <linux/irqdomain.h>
@@ -465,18 +467,14 @@ static int gpio_twl4030_debounce(u32 debounce, u8 mmc_cd)
 				REG_GPIO_DEBEN1, 3);
 }
 
-static struct twl4030_gpio_platform_data *of_gpio_twl4030(struct device *dev,
-				struct twl4030_gpio_platform_data *pdata)
+static struct twl4030_gpio_platform_data *of_gpio_twl4030(struct device *dev)
 {
 	struct twl4030_gpio_platform_data *omap_twl_info;
 
 	omap_twl_info = devm_kzalloc(dev, sizeof(*omap_twl_info), GFP_KERNEL);
 	if (!omap_twl_info)
 		return NULL;
 
-	if (pdata)
-		*omap_twl_info = *pdata;
-
 	omap_twl_info->use_leds = of_property_read_bool(dev->of_node,
 			"ti,use-leds");
 
@@ -504,9 +502,18 @@ static int gpio_twl4030_remove(struct platform_device *pdev)
 	return 0;
 }
 
+/* Called from the registered devm action */
+static void gpio_twl4030_power_off_action(void *data)
+{
+	struct gpio_desc *d = data;
+
+	gpiod_unexport(d);
+	gpiochip_free_own_desc(d);
+}
+
 static int gpio_twl4030_probe(struct platform_device *pdev)
 {
-	struct twl4030_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev);
+	struct twl4030_gpio_platform_data *pdata;
 	struct device_node *node = pdev->dev.of_node;
 	struct gpio_twl4030_priv *priv;
 	int ret, irq_base;
@@ -546,9 +553,7 @@ static int gpio_twl4030_probe(struct platform_device *pdev)
 
 	mutex_init(&priv->mutex);
 
-	if (node)
-		pdata = of_gpio_twl4030(&pdev->dev, pdata);
-
+	pdata = of_gpio_twl4030(&pdev->dev);
 	if (pdata == NULL) {
 		dev_err(&pdev->dev, "Platform data is missing\n");
 		return -ENXIO;
@@ -585,17 +590,32 @@ static int gpio_twl4030_probe(struct platform_device *pdev)
 		goto out;
 	}
 
-	platform_set_drvdata(pdev, priv);
+	/*
+	 * Special quirk for the OMAP3 to hog and export a WLAN power
+	 * GPIO.
+	 */
+	if (IS_ENABLED(CONFIG_ARCH_OMAP3) &&
+	    of_machine_is_compatible("compulab,omap3-sbc-t3730")) {
+		struct gpio_desc *d;
 
-	if (pdata->setup) {
-		int status;
+		d = gpiochip_request_own_desc(&priv->gpio_chip,
+						 2, "wlan pwr",
+						 GPIO_ACTIVE_HIGH,
+						 GPIOD_OUT_HIGH);
+		if (IS_ERR(d))
+			return dev_err_probe(&pdev->dev, PTR_ERR(d),
+					     "unable to hog wlan pwr GPIO\n");
+
+		gpiod_export(d, 0);
+
+		ret = devm_add_action_or_reset(&pdev->dev, gpio_twl4030_power_off_action, d);
+		if (ret)
+			return dev_err_probe(&pdev->dev, ret,
+					     "failed to install power off handler\n");
 
-		status = pdata->setup(&pdev->dev, priv->gpio_chip.base,
-				      TWL4030_GPIO_MAX);
-		if (status)
-			dev_dbg(&pdev->dev, "setup --> %d\n", status);
 	}
 
+	platform_set_drvdata(pdev, priv);
 out:
 	return ret;
 }

include/linux/mfd/twl.h

@@ -593,9 +593,6 @@ struct twl4030_gpio_platform_data {
 	 */
 	u32		pullups;
 	u32		pulldowns;
-
-	int		(*setup)(struct device *dev,
-				unsigned gpio, unsigned ngpio);
 };
 
 struct twl4030_madc_platform_data {