mmc: omap_hsmmc: support deferred probing for GPIOs

If the CD/WP-GPIOs are not provided by the SoC's GPIO controller,
we need to handle the case where omap_hsmmc is probed earlier than
the GPIO controller chosen in the device tree.

Fix this by checking the return value of of_get_named_gpio against
-EPROBE_DEFER and passing it through to the probe function.

Signed-off-by: Jan Luebbe <jlu@pengutronix.de>
Acked-by: Balaji T K <balajitk@ti.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

1 files changed, 12 insertions, 2 deletions

diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index bc5807873b2c..6e44025acf01 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -1717,6 +1717,12 @@ static struct omap_mmc_platform_data *of_get_hsmmc_pdata(struct device *dev)
         struct omap_mmc_platform_data *pdata;
         struct device_node *np = dev->of_node;
         u32 bus_width, max_freq;
+        int cd_gpio, wp_gpio;
+
+        cd_gpio = of_get_named_gpio(np, "cd-gpios", 0);
+        wp_gpio = of_get_named_gpio(np, "wp-gpios", 0);
+        if (cd_gpio == -EPROBE_DEFER || wp_gpio == -EPROBE_DEFER)
+                return ERR_PTR(-EPROBE_DEFER);
 
         pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
         if (!pdata)
@@ -1727,8 +1733,8 @@ static struct omap_mmc_platform_data *of_get_hsmmc_pdata(struct device *dev)
 
         /* This driver only supports 1 slot */
         pdata->nr_slots = 1;
-        pdata->slots[0].switch_pin = of_get_named_gpio(np, "cd-gpios", 0);
-        pdata->slots[0].gpio_wp = of_get_named_gpio(np, "wp-gpios", 0);
+        pdata->slots[0].switch_pin = cd_gpio;
+        pdata->slots[0].gpio_wp = wp_gpio;
 
         if (of_find_property(np, "ti,non-removable", NULL)) {
                 pdata->slots[0].nonremovable = true;
@@ -1774,6 +1780,10 @@ static int omap_hsmmc_probe(struct platform_device *pdev)
         match = of_match_device(of_match_ptr(omap_mmc_of_match), &pdev->dev);
         if (match) {
                 pdata = of_get_hsmmc_pdata(&pdev->dev);
+
+                if (IS_ERR(pdata))
+                        return PTR_ERR(pdata);
+
                 if (match->data) {
                         const u16 *offsetp = match->data;
                         pdata->reg_offset = *offsetp;