src/soc/amd/picasso/uart.c

/* SPDX-License-Identifier: GPL-2.0-only */

#include <acpi/acpigen.h>
#include <console/console.h>
#include <commonlib/helpers.h>
#include <device/mmio.h>
#include <amdblocks/gpio_banks.h>
#include <amdblocks/acpimmio.h>
#include <soc/southbridge.h>
#include <soc/gpio.h>
#include <soc/uart.h>

static const struct _uart_info {
	uintptr_t base;
	struct soc_amd_gpio mux[2];
} uart_info[] = {
	[0] = { APU_UART0_BASE, {
			PAD_NF(GPIO_138, UART0_TXD, PULL_NONE),
			PAD_NF(GPIO_136, UART0_RXD, PULL_NONE),
	} },
	[1] = { APU_UART1_BASE, {
			PAD_NF(GPIO_143, UART1_TXD, PULL_NONE),
			PAD_NF(GPIO_141, UART1_RXD, PULL_NONE),
	} },
	[2] = { APU_UART2_BASE, {
			PAD_NF(GPIO_137, UART2_TXD, PULL_NONE),
			PAD_NF(GPIO_135, UART2_RXD, PULL_NONE),
	} },
	[3] = { APU_UART3_BASE, {
			PAD_NF(GPIO_140, UART3_TXD, PULL_NONE),
			PAD_NF(GPIO_142, UART3_RXD, PULL_NONE),
	} },
};

uintptr_t get_uart_base(int idx)
{
	if (idx < 0 || idx >= ARRAY_SIZE(uart_info))
		return 0;

	return uart_info[idx].base;
}

void clear_uart_legacy_config(void)
{
	write16((void *)FCH_UART_LEGACY_DECODE, 0);
}

void set_uart_config(int idx)
{
	uint32_t uart_ctrl;
	uint16_t uart_leg;

	if (idx < 0 || idx >= ARRAY_SIZE(uart_info))
		return;

	program_gpios(uart_info[idx].mux, 2);

	if (CONFIG(PICASSO_UART_1_8MZ)) {
		uart_ctrl = sm_pci_read32(SMB_UART_CONFIG);
		uart_ctrl |= 1 << (SMB_UART_1_8M_SHIFT + idx);
		sm_pci_write32(SMB_UART_CONFIG, uart_ctrl);
	}

	if (CONFIG(PICASSO_UART_LEGACY) && idx != 3) {
		/* Force 3F8 if idx=0, 2F8 if idx=1, 3E8 if idx=2 */

		/* TODO: make clearer once PPR is updated */
		uart_leg = (idx << 8) | (idx << 10) | (idx << 12) | (idx << 14);
		if (idx == 0)
			uart_leg |= 1 << FCH_LEGACY_3F8_SH;
		else if (idx == 1)
			uart_leg |= 1 << FCH_LEGACY_2F8_SH;
		else if (idx == 2)
			uart_leg |= 1 << FCH_LEGACY_3E8_SH;

		write16((void *)FCH_UART_LEGACY_DECODE, uart_leg);
	}
}

static const char *uart_acpi_name(const struct device *dev)
{
	switch (dev->path.mmio.addr) {
	case APU_UART0_BASE:
		return "FUR0";
	case APU_UART1_BASE:
		return "FUR1";
	case APU_UART2_BASE:
		return "FUR2";
	case APU_UART3_BASE:
		return "FUR3";
	default:
		return NULL;
	}
}

/* Even though this is called enable, it gets called for both enabled and disabled devices. */
static void uart_enable(struct device *dev)
{
	int dev_id;

	switch (dev->path.mmio.addr) {
	case APU_UART0_BASE:
		dev_id = FCH_AOAC_DEV_UART0;
		break;
	case APU_UART1_BASE:
		dev_id = FCH_AOAC_DEV_UART1;
		break;
	case APU_UART2_BASE:
		dev_id = FCH_AOAC_DEV_UART2;
		break;
	case APU_UART3_BASE:
		dev_id = FCH_AOAC_DEV_UART3;
		break;
	default:
		printk(BIOS_ERR, "%s: Unknown device: %s\n", __func__, dev_path(dev));
		return;
	}

	if (dev->enabled) {
		power_on_aoac_device(dev_id);
		wait_for_aoac_enabled(dev_id);
	} else {
		power_off_aoac_device(dev_id);
	}
}

/* This gets called for both enabled and disabled devices. */
static void uart_inject_ssdt(const struct device *dev)
{
	acpigen_write_scope(acpi_device_path(dev));

	acpigen_write_STA(acpi_device_status(dev));

	acpigen_pop_len(); /* Scope */
}

struct device_operations picasso_uart_mmio_ops = {
	.read_resources = noop_read_resources,
	.set_resources = noop_set_resources,
	.scan_bus = scan_static_bus,
	.acpi_name = uart_acpi_name,
	.enable = uart_enable,
	.acpi_fill_ssdt = uart_inject_ssdt,
};