rockchip: Port IO-domain driver for RK3568 from linux

Port the Rockchip IO-domain driver for RK3568 from linux.

The driver auto probe after bind to configure IO-domain based on the
regulator voltage. Compared to the linux driver this driver is not
notified about regulator voltage changes and only configure IO-domain
based on the initial voltage autoset by the regulator.

It is not recommended to enable MMC_IO_VOLTAGE or the mmc signal voltage
and IO-domain may end up out of sync.

Based on the linux commit 28b05a64e47c ("soc: rockchip: io-domain: add
rk3568 support").

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>

drivers/misc/Kconfig

@@ -101,6 +101,15 @@ config ROCKCHIP_OTP
 	  addressing and a length or through child-nodes that are generated
 	  based on the e-fuse map retrieved from the DTS.
 
+config ROCKCHIP_IODOMAIN
+	bool "Rockchip IO-domain driver support"
+	depends on DM_REGULATOR && ARCH_ROCKCHIP
+	default y if ROCKCHIP_RK3568
+	help
+	  Enable support for IO-domains in Rockchip SoCs. It is necessary
+	  for the IO-domain setting of the SoC to match the voltage supplied
+	  by the regulators.
+
 config SIFIVE_OTP
 	bool "SiFive eMemory OTP driver"
 	depends on MISC

drivers/misc/Makefile

@@ -69,6 +69,7 @@ obj-$(CONFIG_SANDBOX) += qfw_sandbox.o
 endif
 obj-$(CONFIG_ROCKCHIP_EFUSE) += rockchip-efuse.o
 obj-$(CONFIG_ROCKCHIP_OTP) += rockchip-otp.o
+obj-$(CONFIG_$(SPL_TPL_)ROCKCHIP_IODOMAIN) += rockchip-io-domain.o
 obj-$(CONFIG_SANDBOX) += syscon_sandbox.o misc_sandbox.o
 obj-$(CONFIG_SIFIVE_OTP) += sifive-otp.o
 obj-$(CONFIG_SMSC_LPC47M) += smsc_lpc47m.o

drivers/misc/rockchip-io-domain.c

@@ -0,0 +1,167 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Rockchip IO Voltage Domain driver
+ *
+ * Ported from linux drivers/soc/rockchip/io-domain.c
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/device_compat.h>
+#include <regmap.h>
+#include <syscon.h>
+#include <power/regulator.h>
+
+#define MAX_SUPPLIES		16
+
+/*
+ * The max voltage for 1.8V and 3.3V come from the Rockchip datasheet under
+ * "Recommended Operating Conditions" for "Digital GPIO".   When the typical
+ * is 3.3V the max is 3.6V.  When the typical is 1.8V the max is 1.98V.
+ *
+ * They are used like this:
+ * - If the voltage on a rail is above the "1.8" voltage (1.98V) we'll tell the
+ *   SoC we're at 3.3.
+ * - If the voltage on a rail is above the "3.3" voltage (3.6V) we'll consider
+ *   that to be an error.
+ */
+#define MAX_VOLTAGE_1_8		1980000
+#define MAX_VOLTAGE_3_3		3600000
+
+#define RK3568_PMU_GRF_IO_VSEL0		0x0140
+#define RK3568_PMU_GRF_IO_VSEL1		0x0144
+#define RK3568_PMU_GRF_IO_VSEL2		0x0148
+
+struct rockchip_iodomain_soc_data {
+	int grf_offset;
+	const char *supply_names[MAX_SUPPLIES];
+	int (*write)(struct regmap *grf, int idx, int uV);
+};
+
+static int rk3568_iodomain_write(struct regmap *grf, int idx, int uV)
+{
+	u32 is_3v3 = uV > MAX_VOLTAGE_1_8;
+	u32 val0, val1;
+	int b;
+
+	switch (idx) {
+	case 0: /* pmuio1 */
+		break;
+	case 1: /* pmuio2 */
+		b = idx;
+		val0 = BIT(16 + b) | (is_3v3 ? 0 : BIT(b));
+		b = idx + 4;
+		val1 = BIT(16 + b) | (is_3v3 ? BIT(b) : 0);
+
+		regmap_write(grf, RK3568_PMU_GRF_IO_VSEL2, val0);
+		regmap_write(grf, RK3568_PMU_GRF_IO_VSEL2, val1);
+		break;
+	case 3: /* vccio2 */
+		break;
+	case 2: /* vccio1 */
+	case 4: /* vccio3 */
+	case 5: /* vccio4 */
+	case 6: /* vccio5 */
+	case 7: /* vccio6 */
+	case 8: /* vccio7 */
+		b = idx - 1;
+		val0 = BIT(16 + b) | (is_3v3 ? 0 : BIT(b));
+		val1 = BIT(16 + b) | (is_3v3 ? BIT(b) : 0);
+
+		regmap_write(grf, RK3568_PMU_GRF_IO_VSEL0, val0);
+		regmap_write(grf, RK3568_PMU_GRF_IO_VSEL1, val1);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct rockchip_iodomain_soc_data soc_data_rk3568_pmu = {
+	.grf_offset = 0x140,
+	.supply_names = {
+		NULL,
+		"pmuio2-supply",
+		"vccio1-supply",
+		NULL,
+		"vccio3-supply",
+		"vccio4-supply",
+		"vccio5-supply",
+		"vccio6-supply",
+		"vccio7-supply",
+	},
+	.write = rk3568_iodomain_write,
+};
+
+static const struct udevice_id rockchip_iodomain_ids[] = {
+	{
+		.compatible = "rockchip,rk3568-pmu-io-voltage-domain",
+		.data = (ulong)&soc_data_rk3568_pmu,
+	},
+	{ }
+};
+
+static int rockchip_iodomain_bind(struct udevice *dev)
+{
+	/*
+	 * According to the Hardware Design Guide, IO-domain configuration must
+	 * be consistent with the power supply voltage (1.8V or 3.3V).
+	 * Probe after bind to configure IO-domain voltage early during boot.
+	 */
+	dev_or_flags(dev, DM_FLAG_PROBE_AFTER_BIND);
+
+	return 0;
+}
+
+static int rockchip_iodomain_probe(struct udevice *dev)
+{
+	struct rockchip_iodomain_soc_data *soc_data =
+		(struct rockchip_iodomain_soc_data *)dev_get_driver_data(dev);
+	struct regmap *grf;
+	int ret;
+
+	grf = syscon_get_regmap(dev_get_parent(dev));
+	if (IS_ERR(grf))
+		return PTR_ERR(grf);
+
+	for (int i = 0; i < MAX_SUPPLIES; i++) {
+		const char *supply_name = soc_data->supply_names[i];
+		struct udevice *reg;
+		int uV;
+
+		if (!supply_name)
+			continue;
+
+		ret = device_get_supply_regulator(dev, supply_name, &reg);
+		if (ret)
+			continue;
+
+		ret = regulator_autoset(reg);
+		if (ret && ret != -EALREADY && ret != -EMEDIUMTYPE &&
+		    ret != -ENOSYS)
+			continue;
+
+		uV = regulator_get_value(reg);
+		if (uV <= 0)
+			continue;
+
+		if (uV > MAX_VOLTAGE_3_3) {
+			dev_crit(dev, "%s: %d uV is too high. May damage SoC!\n",
+				 supply_name, uV);
+			continue;
+		}
+
+		soc_data->write(grf, i, uV);
+	}
+
+	return 0;
+}
+
+U_BOOT_DRIVER(rockchip_iodomain) = {
+	.name = "rockchip_iodomain",
+	.id = UCLASS_NOP,
+	.of_match = rockchip_iodomain_ids,
+	.bind = rockchip_iodomain_bind,
+	.probe = rockchip_iodomain_probe,
+};