drivers: pinctrl: create Tegra DM pinctrl driver

The existing pinctrl driver available for Tegra SOC is well
designed, but it lacks DM support. Let's add a DM compatible
overlay, which allows use of the device tree, along with preserving
backward compatibility with all existing setups and the ability
to use it in SPL board configuration stage.

Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
diff --git a/drivers/pinctrl/tegra/pinctrl-tegra.c b/drivers/pinctrl/tegra/pinctrl-tegra.c
new file mode 100644
index 0000000..ad7112a
--- /dev/null
+++ b/drivers/pinctrl/tegra/pinctrl-tegra.c
@@ -0,0 +1,248 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  (C) Copyright 2023
+ *  Svyatoslav Ryhel <clamor95@gmail.com>
+ */
+
+#include <dm.h>
+#include <dm/device_compat.h>
+#include <dm/pinctrl.h>
+#include <stdlib.h>
+
+#include <asm/arch/pinmux.h>
+
+static void tegra_pinctrl_set_drive(struct udevice *config, int drvcnt)
+{
+	struct pmux_drvgrp_config *drive_group;
+	int i, ret, pad_id;
+	const char **pads;
+
+	drive_group = kmalloc_array(drvcnt, sizeof(*drive_group), GFP_KERNEL);
+	if (!drive_group) {
+		log_debug("%s: cannot allocate drive group array\n", __func__);
+		return;
+	}
+
+	drive_group[0].slwf = dev_read_u32_default(config, "nvidia,slew-rate-falling", 0);
+	drive_group[0].slwr = dev_read_u32_default(config, "nvidia,slew-rate-rising", 0);
+	drive_group[0].drvup = dev_read_u32_default(config, "nvidia,pull-up-strength", 0);
+	drive_group[0].drvdn = dev_read_u32_default(config, "nvidia,pull-down-strength", 0);
+#ifdef TEGRA_PMX_GRPS_HAVE_LPMD
+	drive_group[0].lpmd = dev_read_u32_default(config, "nvidia,low-power-mode", 0);
+#endif
+#ifdef TEGRA_PMX_GRPS_HAVE_SCHMT
+	drive_group[0].schmt = dev_read_u32_default(config, "nvidia,schmitt", 0);
+#endif
+#ifdef TEGRA_PMX_GRPS_HAVE_HSM
+	drive_group[0].hsm = dev_read_u32_default(config, "nvidia,high-speed-mode", 0);
+#endif
+
+	for (i = 1; i < drvcnt; i++)
+		memcpy(&drive_group[i], &drive_group[0], sizeof(drive_group[0]));
+
+	ret = dev_read_string_list(config, "nvidia,pins", &pads);
+	if (ret < 0) {
+		log_debug("%s: could not parse property nvidia,pins\n", __func__);
+		goto exit;
+	}
+
+	for (i = 0; i < drvcnt; i++) {
+		for (pad_id = 0; pad_id < PMUX_DRVGRP_COUNT; pad_id++)
+			if (tegra_pinctrl_to_drvgrp[pad_id])
+				if (!strcmp(pads[i], tegra_pinctrl_to_drvgrp[pad_id])) {
+					drive_group[i].drvgrp = pad_id;
+					break;
+				}
+
+		debug("%s drvmap: %d, %d, %d, %d, %d\n", pads[i],
+		      drive_group[i].drvgrp, drive_group[i].slwf,
+		      drive_group[i].slwr, drive_group[i].drvup,
+		      drive_group[i].drvdn);
+	}
+
+	pinmux_config_drvgrp_table(drive_group, drvcnt);
+
+	free(pads);
+exit:
+	kfree(drive_group);
+}
+
+static void tegra_pinctrl_set_pin(struct udevice *config, int pincnt)
+{
+	struct pmux_pingrp_config *pinmux_group;
+	int i, ret, pin_id;
+	const char *function;
+	const char **pins;
+
+	pinmux_group = kmalloc_array(pincnt, sizeof(*pinmux_group), GFP_KERNEL);
+	if (!pinmux_group) {
+		log_debug("%s: cannot allocate pinmux group array\n", __func__);
+		return;
+	}
+
+	/* decode function id and fill the first copy of pmux_pingrp_config */
+	function = dev_read_string(config, "nvidia,function");
+	if (function)
+		for (i = 0; i < PMUX_FUNC_COUNT; i++)
+			if (tegra_pinctrl_to_func[i])
+				if (!strcmp(function, tegra_pinctrl_to_func[i]))
+					break;
+
+	pinmux_group[0].func = i;
+
+	pinmux_group[0].pull = dev_read_u32_default(config, "nvidia,pull", 0);
+	pinmux_group[0].tristate = dev_read_u32_default(config, "nvidia,tristate", 0);
+#ifdef TEGRA_PMX_PINS_HAVE_E_INPUT
+	pinmux_group[0].io = dev_read_u32_default(config, "nvidia,enable-input", 0);
+#endif
+#ifdef TEGRA_PMX_PINS_HAVE_LOCK
+	pinmux_group[0].lock = dev_read_u32_default(config, "nvidia,lock", 0);
+#endif
+#ifdef TEGRA_PMX_PINS_HAVE_OD
+	pinmux_group[0].od = dev_read_u32_default(config, "nvidia,open-drain", 0);
+#endif
+#ifdef TEGRA_PMX_PINS_HAVE_IO_RESET
+	pinmux_group[0].ioreset = dev_read_u32_default(config, "nvidia,io-reset", 0);
+#endif
+#ifdef TEGRA_PMX_PINS_HAVE_RCV_SEL
+	pinmux_group[0].rcv_sel = dev_read_u32_default(config, "nvidia,rcv-sel", 0);
+#endif
+#ifdef TEGRA_PMX_PINS_HAVE_E_IO_HV
+	pinmux_group[0].e_io_hv = dev_read_u32_default(config, "nvidia,io-hv", 0);
+#endif
+#ifdef TEGRA_PMX_PINS_HAVE_SCHMT
+	pinmux_group[0].schmt = dev_read_u32_default(config, "nvidia,schmitt", 0);
+#endif
+#ifdef TEGRA_PMX_PINS_HAVE_HSM
+	pinmux_group[0].hsm = dev_read_u32_default(config, "nvidia,high-speed-mode", 0);
+#endif
+
+	for (i = 1; i < pincnt; i++)
+		memcpy(&pinmux_group[i], &pinmux_group[0], sizeof(pinmux_group[0]));
+
+	ret = dev_read_string_list(config, "nvidia,pins", &pins);
+	if (ret < 0) {
+		log_debug("%s: could not parse property nvidia,pins\n", __func__);
+		goto exit;
+	}
+
+	for (i = 0; i < pincnt; i++) {
+		for (pin_id = 0; pin_id < PMUX_PINGRP_COUNT; pin_id++)
+			if (tegra_pinctrl_to_pingrp[pin_id])
+				if (!strcmp(pins[i], tegra_pinctrl_to_pingrp[pin_id])) {
+					pinmux_group[i].pingrp = pin_id;
+					break;
+				}
+
+		debug("%s pinmap: %d, %d, %d, %d\n", pins[i],
+		      pinmux_group[i].pingrp, pinmux_group[i].func,
+		      pinmux_group[i].pull, pinmux_group[i].tristate);
+	}
+
+	pinmux_config_pingrp_table(pinmux_group, pincnt);
+
+	free(pins);
+exit:
+	kfree(pinmux_group);
+}
+
+static int tegra_pinctrl_set_state(struct udevice *dev, struct udevice *config)
+{
+	struct udevice *child;
+	int ret;
+	const char *name;
+
+	device_foreach_child(child, config) {
+		/* Pinmux node can contain pins and drives */
+		ret = dev_read_string_index(child, "nvidia,pins", 0,
+					    &name);
+		if (ret < 0) {
+			log_debug("%s: could not parse property nvidia,pins\n", __func__);
+			return ret;
+		}
+
+		ret = dev_read_string_count(child, "nvidia,pins");
+		if (ret < 0) {
+			log_debug("%s: could not count nvidia,pins\n", __func__);
+			return ret;
+		}
+
+		if (!strncmp(name, "drive_", 6))
+			/* Drive node is detected */
+			tegra_pinctrl_set_drive(child, ret);
+		else
+			/* Pin node is detected */
+			tegra_pinctrl_set_pin(child, ret);
+	}
+
+	return 0;
+}
+
+static int tegra_pinctrl_get_pins_count(struct udevice *dev)
+{
+	return PMUX_PINGRP_COUNT;
+}
+
+static const char *tegra_pinctrl_get_pin_name(struct udevice *dev,
+					      unsigned int selector)
+{
+	return tegra_pinctrl_to_pingrp[selector];
+}
+
+static int tegra_pinctrl_get_groups_count(struct udevice *dev)
+{
+	return PMUX_DRVGRP_COUNT;
+}
+
+static const char *tegra_pinctrl_get_group_name(struct udevice *dev,
+						unsigned int selector)
+{
+	return tegra_pinctrl_to_drvgrp[selector];
+}
+
+static int tegra_pinctrl_get_functions_count(struct udevice *dev)
+{
+	return PMUX_FUNC_COUNT;
+}
+
+static const char *tegra_pinctrl_get_function_name(struct udevice *dev,
+						   unsigned int selector)
+{
+	return tegra_pinctrl_to_func[selector];
+}
+
+const struct pinctrl_ops tegra_pinctrl_ops = {
+	.get_pins_count = tegra_pinctrl_get_pins_count,
+	.get_pin_name = tegra_pinctrl_get_pin_name,
+	.get_groups_count = tegra_pinctrl_get_groups_count,
+	.get_group_name = tegra_pinctrl_get_group_name,
+	.get_functions_count = tegra_pinctrl_get_functions_count,
+	.get_function_name = tegra_pinctrl_get_function_name,
+	.set_state = tegra_pinctrl_set_state,
+};
+
+static int tegra_pinctrl_bind(struct udevice *dev)
+{
+	/*
+	 * Make sure that the pinctrl driver gets probed after binding
+	 * to provide initial configuration and assure that further
+	 * probed devices are working correctly.
+	 */
+	dev_or_flags(dev, DM_FLAG_PROBE_AFTER_BIND);
+
+	return 0;
+}
+
+static const struct udevice_id tegra_pinctrl_ids[] = {
+	{ .compatible = "nvidia,tegra30-pinmux" },
+	{ .compatible = "nvidia,tegra114-pinmux" },
+	{ },
+};
+
+U_BOOT_DRIVER(tegra_pinctrl) = {
+	.name		= "tegra_pinctrl",
+	.id		= UCLASS_PINCTRL,
+	.of_match	= tegra_pinctrl_ids,
+	.bind		= tegra_pinctrl_bind,
+	.ops		= &tegra_pinctrl_ops,
+};