pinctrl: microchip-sgpio: add ability to be used in a non-mmio configuration

There are a few Ocelot chips that can contain SGPIO 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@in-advantage.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20220905162132.2943088-6-colin.foster@in-advantage.com

drivers/pinctrl/pinctrl-microchip-sgpio.c

@@ -12,6 +12,7 @@
 #include <linux/clk.h>
 #include <linux/gpio/driver.h>
 #include <linux/io.h>
+#include <linux/mfd/ocelot.h>
 #include <linux/mod_devicetable.h>
 #include <linux/module.h>
 #include <linux/pinctrl/pinmux.h>
@@ -904,7 +905,6 @@ static int microchip_sgpio_probe(struct platform_device *pdev)
 	struct reset_control *reset;
 	struct sgpio_priv *priv;
 	struct clk *clk;
-	u32 __iomem *regs;
 	u32 val;
 	struct regmap_config regmap_config = {
 		.reg_bits = 32,
@@ -937,11 +937,7 @@ static int microchip_sgpio_probe(struct platform_device *pdev)
 		return -EINVAL;
 	}
 
-	regs = devm_platform_ioremap_resource(pdev, 0);
-	if (IS_ERR(regs))
-		return PTR_ERR(regs);
-
-	priv->regs = devm_regmap_init_mmio(dev, regs, &regmap_config);
+	priv->regs = ocelot_regmap_from_resource(pdev, 0, &regmap_config);
 	if (IS_ERR(priv->regs))
 		return PTR_ERR(priv->regs);