u-boot/drivers/misc/qfw_mmio.c
Asherah Connor 5830b57bf9 qemu: add MMIO driver for QFW
Add MMIO driver for QFW.

Note that there is no consumer as of this patch.

Signed-off-by: Asherah Connor <ashe@kivikakk.ee>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
2021-04-12 17:45:40 -04:00

120 lines
2.5 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* MMIO interface for QFW
*
* (C) Copyright 2015 Miao Yan <yanmiaobest@gmail.com>
* (C) Copyright 2021 Asherah Connor <ashe@kivikakk.ee>
*/
#define LOG_CATEGORY UCLASS_QFW
#include <asm/types.h>
#include <asm/io.h>
#include <dm.h>
#include <dm/device.h>
#include <qfw.h>
struct qfw_mmio {
/*
* Each access to the 64-bit data register can be 8/16/32/64 bits wide.
*/
union {
u8 data8;
u16 data16;
u32 data32;
u64 data64;
};
u16 selector;
u8 padding[6];
u64 dma;
};
struct qfw_mmio_plat {
volatile struct qfw_mmio *mmio;
};
static void qfw_mmio_read_entry_io(struct udevice *dev, u16 entry, u32 size,
void *address)
{
struct qfw_mmio_plat *plat = dev_get_plat(dev);
/*
* writing FW_CFG_INVALID will cause read operation to resume at last
* offset, otherwise read will start at offset 0
*
* Note: on platform where the control register is MMIO, the register
* is big endian.
*/
if (entry != FW_CFG_INVALID)
plat->mmio->selector = cpu_to_be16(entry);
/* the endianness of data register is string-preserving */
while (size >= 8) {
*(u64 *)address = plat->mmio->data64;
address += 8;
size -= 8;
}
while (size >= 4) {
*(u32 *)address = plat->mmio->data32;
address += 4;
size -= 4;
}
while (size >= 2) {
*(u16 *)address = plat->mmio->data16;
address += 2;
size -= 2;
}
while (size >= 1) {
*(u8 *)address = plat->mmio->data8;
address += 1;
size -= 1;
}
}
/* Read configuration item using fw_cfg DMA interface */
static void qfw_mmio_read_entry_dma(struct udevice *dev, struct qfw_dma *dma)
{
struct qfw_mmio_plat *plat = dev_get_plat(dev);
/* the DMA address register is big-endian */
plat->mmio->dma = cpu_to_be64((uintptr_t)dma);
while (be32_to_cpu(dma->control) & ~FW_CFG_DMA_ERROR);
}
static int qfw_mmio_of_to_plat(struct udevice *dev)
{
struct qfw_mmio_plat *plat = dev_get_plat(dev);
plat->mmio = map_physmem(dev_read_addr(dev),
sizeof(struct qfw_mmio),
MAP_NOCACHE);
return 0;
}
static int qfw_mmio_probe(struct udevice *dev)
{
return qfw_register(dev);
}
static struct dm_qfw_ops qfw_mmio_ops = {
.read_entry_io = qfw_mmio_read_entry_io,
.read_entry_dma = qfw_mmio_read_entry_dma,
};
static const struct udevice_id qfw_mmio_ids[] = {
{ .compatible = "qemu,fw-cfg-mmio" },
{}
};
U_BOOT_DRIVER(qfw_mmio) = {
.name = "qfw_mmio",
.id = UCLASS_QFW,
.of_match = qfw_mmio_ids,
.plat_auto = sizeof(struct qfw_mmio_plat),
.of_to_plat = qfw_mmio_of_to_plat,
.probe = qfw_mmio_probe,
.ops = &qfw_mmio_ops,
};