drivers/gpio/turris_omnia_mcu.c

// SPDX-License-Identifier: GPL-2.0+
// (C) 2022 Pali Rohár <pali@kernel.org>

#include <common.h>
#include <dm.h>
#include <i2c.h>
#include <turris-omnia-mcu-interface.h>
#include <asm/byteorder.h>
#include <asm/gpio.h>
#include <linux/log2.h>

struct turris_omnia_mcu_info {
	u32 features;
};

static int turris_omnia_mcu_get_function(struct udevice *dev, uint offset)
{
	struct turris_omnia_mcu_info *info = dev_get_plat(dev);

	switch (offset) {
	/* bank 0 */
	case 0 ... 15:
		switch (offset) {
		case ilog2(STS_USB30_PWRON):
		case ilog2(STS_USB31_PWRON):
		case ilog2(STS_ENABLE_4V5):
		case ilog2(STS_BUTTON_MODE):
			return GPIOF_OUTPUT;
		default:
			return GPIOF_INPUT;
		}

	/* bank 1 - supported only when FEAT_EXT_CMDS is set */
	case (16 + 0) ... (16 + 31):
		if (!(info->features & FEAT_EXT_CMDS))
			return -EINVAL;
		return GPIOF_INPUT;

	/* bank 2 - supported only when FEAT_EXT_CMDS and FEAT_PERIPH_MCU is set */
	case (16 + 32 + 0) ... (16 + 32 + 15):
		if (!(info->features & FEAT_EXT_CMDS))
			return -EINVAL;
		if (!(info->features & FEAT_PERIPH_MCU))
			return -EINVAL;
		return GPIOF_OUTPUT;

	default:
		return -EINVAL;
	}
}

static int turris_omnia_mcu_get_value(struct udevice *dev, uint offset)
{
	struct turris_omnia_mcu_info *info = dev_get_plat(dev);
	u32 val32;
	u16 val16;
	int ret;

	switch (offset) {
	/* bank 0 */
	case 0 ... 15:
		ret = dm_i2c_read(dev, CMD_GET_STATUS_WORD, (void *)&val16,
				  sizeof(val16));
		if (ret)
			return ret;

		return !!(le16_to_cpu(val16) & BIT(offset));

	/* bank 1 - supported only when FEAT_EXT_CMDS is set */
	case (16 + 0) ... (16 + 31):
		if (!(info->features & FEAT_EXT_CMDS))
			return -EINVAL;

		ret = dm_i2c_read(dev, CMD_GET_EXT_STATUS_DWORD, (void *)&val32,
				  sizeof(val32));
		if (ret)
			return ret;

		return !!(le32_to_cpu(val32) & BIT(offset - 16));

	/* bank 2 - supported only when FEAT_EXT_CMDS and FEAT_PERIPH_MCU is set */
	case (16 + 32 + 0) ... (16 + 32 + 15):
		if (!(info->features & FEAT_EXT_CMDS))
			return -EINVAL;
		if (!(info->features & FEAT_PERIPH_MCU))
			return -EINVAL;

		ret = dm_i2c_read(dev, CMD_GET_EXT_CONTROL_STATUS,
				  (void *)&val16, sizeof(val16));
		if (ret)
			return ret;

		return !!(le16_to_cpu(val16) & BIT(offset - 16 - 32));

	default:
		return -EINVAL;
	}
}

static int turris_omnia_mcu_set_value(struct udevice *dev, uint offset, int value)
{
	struct turris_omnia_mcu_info *info = dev_get_plat(dev);
	u16 valmask16[2];
	u8 valmask8[2];

	switch (offset) {
	/* bank 0 */
	case 0 ... 15:
		switch (offset) {
		case ilog2(STS_USB30_PWRON):
			valmask8[1] = CTL_USB30_PWRON;
			break;
		case ilog2(STS_USB31_PWRON):
			valmask8[1] = CTL_USB31_PWRON;
			break;
		case ilog2(STS_ENABLE_4V5):
			valmask8[1] = CTL_ENABLE_4V5;
			break;
		case ilog2(STS_BUTTON_MODE):
			valmask8[1] = CTL_BUTTON_MODE;
			break;
		default:
			return -EINVAL;
		}

		valmask8[0] = value ? valmask8[1] : 0;

		return dm_i2c_write(dev, CMD_GENERAL_CONTROL, valmask8,
				    sizeof(valmask8));

	/* bank 2 - supported only when FEAT_EXT_CMDS and FEAT_PERIPH_MCU is set */
	case (16 + 32 + 0) ... (16 + 32 + 15):
		if (!(info->features & FEAT_EXT_CMDS))
			return -EINVAL;
		if (!(info->features & FEAT_PERIPH_MCU))
			return -EINVAL;

		valmask16[1] = cpu_to_le16(BIT(offset - 16 - 32));
		valmask16[0] = value ? valmask16[1] : 0;

		return dm_i2c_write(dev, CMD_EXT_CONTROL, (void *)valmask16,
				    sizeof(valmask16));

	default:
		return -EINVAL;
	}
}

static int turris_omnia_mcu_direction_input(struct udevice *dev, uint offset)
{
	int ret;

	ret = turris_omnia_mcu_get_function(dev, offset);
	if (ret < 0)
		return ret;
	else if (ret != GPIOF_INPUT)
		return -EOPNOTSUPP;

	return 0;
}

static int turris_omnia_mcu_direction_output(struct udevice *dev, uint offset, int value)
{
	int ret;

	ret = turris_omnia_mcu_get_function(dev, offset);
	if (ret < 0)
		return ret;
	else if (ret != GPIOF_OUTPUT)
		return -EOPNOTSUPP;

	return turris_omnia_mcu_set_value(dev, offset, value);
}

static int turris_omnia_mcu_xlate(struct udevice *dev, struct gpio_desc *desc,
				  struct ofnode_phandle_args *args)
{
	uint bank, gpio, flags, offset;
	int ret;

	if (args->args_count != 3)
		return -EINVAL;

	bank = args->args[0];
	gpio = args->args[1];
	flags = args->args[2];

	switch (bank) {
	case 0:
		if (gpio >= 16)
			return -EINVAL;
		offset = gpio;
		break;
	case 1:
		if (gpio >= 32)
			return -EINVAL;
		offset = 16 + gpio;
		break;
	case 2:
		if (gpio >= 16)
			return -EINVAL;
		offset = 16 + 32 + gpio;
		break;
	default:
		return -EINVAL;
	}

	ret = turris_omnia_mcu_get_function(dev, offset);
	if (ret < 0)
		return ret;

	desc->offset = offset;
	desc->flags = gpio_flags_xlate(flags);

	return 0;
}

static const struct dm_gpio_ops turris_omnia_mcu_ops = {
	.direction_input	= turris_omnia_mcu_direction_input,
	.direction_output	= turris_omnia_mcu_direction_output,
	.get_value		= turris_omnia_mcu_get_value,
	.set_value		= turris_omnia_mcu_set_value,
	.get_function		= turris_omnia_mcu_get_function,
	.xlate			= turris_omnia_mcu_xlate,
};

static int turris_omnia_mcu_probe(struct udevice *dev)
{
	struct turris_omnia_mcu_info *info = dev_get_plat(dev);
	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
	u32 dword;
	u16 word;
	int ret;

	ret = dm_i2c_read(dev, CMD_GET_STATUS_WORD, (void *)&word, sizeof(word));
	if (ret < 0) {
		printf("Error: turris_omnia_mcu CMD_GET_STATUS_WORD failed: %d\n",
		       ret);
		return ret;
	}

	if (le16_to_cpu(word) & STS_FEATURES_SUPPORTED) {
		/* try read 32-bit features */
		ret = dm_i2c_read(dev, CMD_GET_FEATURES, (void *)&dword,
				  sizeof(dword));
		if (ret < 0) {
			/* try read 16-bit features */
			ret = dm_i2c_read(dev, CMD_GET_FEATURES, (void *)&word,
					  sizeof(word));
			if (ret < 0) {
				printf("Error: turris_omnia_mcu CMD_GET_FEATURES failed: %d\n",
				       ret);
				return ret;
			}

			info->features = le16_to_cpu(word);
		} else {
			info->features = le32_to_cpu(dword);
			if (info->features & FEAT_FROM_BIT_16_INVALID)
				info->features &= GENMASK(15, 0);
		}
	}

	uc_priv->bank_name = "mcu_";

	if ((info->features & FEAT_EXT_CMDS) && (info->features & FEAT_PERIPH_MCU))
		uc_priv->gpio_count = 16 + 32 + 16;
	else if (info->features & FEAT_EXT_CMDS)
		uc_priv->gpio_count = 16 + 32;
	else
		uc_priv->gpio_count = 16;

	return 0;
}

static const struct udevice_id turris_omnia_mcu_ids[] = {
	{ .compatible = "cznic,turris-omnia-mcu" },
	{ }
};

U_BOOT_DRIVER(turris_omnia_mcu) = {
	.name		= "turris-omnia-mcu",
	.id		= UCLASS_GPIO,
	.ops		= &turris_omnia_mcu_ops,
	.probe		= turris_omnia_mcu_probe,
	.plat_auto	= sizeof(struct turris_omnia_mcu_info),
	.of_match	= turris_omnia_mcu_ids,
};