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/* SPDX-License-Identifier: GPL-2.0-only */
#include <stdint.h>
#include <stddef.h>
#include <device/pci_ops.h>
#include <console/uart.h>
#include <device/pci.h>
#include "uart8250reg.h"
static int oxpcie_present;
static DEVTREE_CONST u32 uart0_base = CONFIG_EARLY_PCI_MMIO_BASE + 0x1000;
int pci_early_device_probe(u8 bus, u8 dev, u32 mmio_base)
{
pci_devfn_t device = PCI_DEV(bus, dev, 0);
u32 id = pci_s_read_config32(device, PCI_VENDOR_ID);
switch (id) {
case 0xc1181415: /* e.g. Startech PEX1S1PMINI function 0 */
/* On this device function 0 is the parallel port, and
* function 3 is the serial port. So let's go look for
* the UART.
*/
device = PCI_DEV(bus, dev, 3);
id = pci_s_read_config32(device, PCI_VENDOR_ID);
if (id != 0xc11b1415)
return -1;
break;
case 0xc11b1415: /* e.g. Startech PEX1S1PMINI function 3 */
case 0xc1581415: /* e.g. Startech MPEX2S952 */
break;
default:
/* No UART here. */
return -1;
}
/* Sanity-check, we assume fixed location. */
if (mmio_base != CONFIG_EARLY_PCI_MMIO_BASE)
return -1;
/* Setup base address on device */
pci_s_write_config32(device, PCI_BASE_ADDRESS_0, mmio_base);
/* Enable memory on device */
u16 reg16 = pci_s_read_config16(device, PCI_COMMAND);
reg16 |= PCI_COMMAND_MEMORY;
pci_s_write_config16(device, PCI_COMMAND, reg16);
oxpcie_present = 1;
return 0;
}
/*
* Stages that do not call pci_early_device_probe() identify an
* enabled UART with a test read. Since PCI bus enumeration
* has not happened PCI configuration register access is not
* possible here.
*/
static int uart_presence(uintptr_t base)
{
/* LCR has no side-effects on reads. */
const u8 reg = UART8250_LCR;
u8 val;
if (CONFIG(DRIVERS_UART_8250MEM_32))
val = read32p(base + 4 * reg) & 0xff;
else
val = read8p(base + reg);
if (val == 0xff)
return -1;
/* Something decoded MMIO read, assume it was the UART. */
return 1;
}
static bool oxpcie_uart_active(void)
{
if (oxpcie_present == 0)
oxpcie_present = uart_presence(uart0_base);
if (oxpcie_present > 0)
return true;
if (oxpcie_present < 0)
return false;
/* not reached */
return false;
}
uintptr_t uart_platform_base(unsigned int idx)
{
if ((idx < 8) && oxpcie_uart_active())
return uart0_base + idx * 0x200;
return 0;
}
void oxford_remap(u32 new_base)
{
#if ENV_RAMSTAGE
uart0_base = new_base + 0x1000;
#endif
}
unsigned int uart_platform_refclk(void)
{
return 62500000;
}
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