[RFC v8 net-next 05/16] pinctrl: ocelot: add ability to be used in a non-mmio configuration

[Colin Foster <colin.foster@xxxxxxxxxxxxxxxx>]

There are a few Ocelot chips that contain pinctrl logic, but can be
controlled externally. Specifically the VSC7511, 7512, 7513 and 7514. In
the externally controlled configurations these registers are not
memory-mapped.

Add support for these non-memory-mapped configurations.

Signed-off-by: Colin Foster <colin.foster@xxxxxxxxxxxxxxxx>
---
 drivers/pinctrl/pinctrl-ocelot.c | 31 ++++++++++++++++++++++++-------
 1 file changed, 24 insertions(+), 7 deletions(-)

diff --git a/drivers/pinctrl/pinctrl-ocelot.c b/drivers/pinctrl/pinctrl-ocelot.c
index 30577fedb7fc..4995c90019c5 100644
--- a/drivers/pinctrl/pinctrl-ocelot.c
+++ b/drivers/pinctrl/pinctrl-ocelot.c
@@ -20,6 +20,7 @@
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
 #include <linux/slab.h>
+#include <soc/mscc/ocelot.h>
 
 #include "core.h"
 #include "pinconf.h"
@@ -1215,6 +1216,9 @@ static int lan966x_pinmux_set_mux(struct pinctrl_dev *pctldev,
 	return 0;
 }
 
+#if defined(REG)
+#undef REG
+#endif
 #define REG(r, info, p) ((r) * (info)->stride + (4 * ((p) / 32)))
 
 static int ocelot_gpio_set_direction(struct pinctrl_dev *pctldev,
@@ -1908,6 +1912,7 @@ static int ocelot_pinctrl_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct ocelot_pinctrl *info;
 	struct regmap *pincfg;
+	struct resource *res;
 	void __iomem *base;
 	int ret;
 	struct regmap_config regmap_config = {
@@ -1922,16 +1927,28 @@ static int ocelot_pinctrl_probe(struct platform_device *pdev)
 
 	info->desc = (struct pinctrl_desc *)device_get_match_data(dev);
 
-	base = devm_ioremap_resource(dev,
-			platform_get_resource(pdev, IORESOURCE_MEM, 0));
-	if (IS_ERR(base))
-		return PTR_ERR(base);
+	base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL);
+	if (IS_ERR(base)) {
+		/*
+		 * Fall back to using IORESOURCE_REG, which is possible in an
+		 * MFD configuration
+		 */
+		res = platform_get_resource(pdev, IORESOURCE_REG, 0);
+		if (!res) {
+			dev_err(dev, "Failed to get resource\n");
+			return -ENODEV;
+		}
 
-	info->stride = 1 + (info->desc->npins - 1) / 32;
+		info->map = ocelot_init_regmap_from_resource(dev, res);
+	} else {
+		regmap_config.max_register =
+			OCELOT_GPIO_SD_MAP * info->stride + 15 * 4;
 
-	regmap_config.max_register = OCELOT_GPIO_SD_MAP * info->stride + 15 * 4;
+		info->map = devm_regmap_init_mmio(dev, base, &regmap_config);
+	}
+
+	info->stride = 1 + (info->desc->npins - 1) / 32;
 
-	info->map = devm_regmap_init_mmio(dev, base, &regmap_config);
 	if (IS_ERR(info->map)) {
 		dev_err(dev, "Failed to create regmap\n");
 		return PTR_ERR(info->map);
-- 
2.25.1