u-boot/drivers/axi/ihs_axi.c
Simon Glass 41575d8e4c dm: treewide: Rename auto_alloc_size members to be shorter
This construct is quite long-winded. In earlier days it made some sense
since auto-allocation was a strange concept. But with driver model now
used pretty universally, we can shorten this to 'auto'. This reduces
verbosity and makes it easier to read.

Coincidentally it also ensures that every declaration is on one line,
thus making dtoc's job easier.

Signed-off-by: Simon Glass <sjg@chromium.org>
2020-12-13 08:00:25 -07:00

296 lines
8.5 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2016
* Dirk Eibach, Guntermann & Drunck GmbH, dirk.eibach@gdsys.cc
*
* (C) Copyright 2017, 2018
* Mario Six, Guntermann & Drunck GmbH, mario.six@gdsys.cc
*/
#include <common.h>
#include <axi.h>
#include <dm.h>
#include <log.h>
#include <regmap.h>
#include <linux/bitops.h>
#include <linux/delay.h>
/**
* struct ihs_axi_regs - Structure for the register map of a IHS AXI device
* @interrupt_status: Status register to indicate certain events (e.g.
* error during transfer, transfer complete, etc.)
* @interrupt_enable_control: Register to both control which statuses will be
* indicated in the interrupt_status register, and
* to change bus settings
* @address_lsb: Least significant 16-bit word of the address of a
* device to transfer data from/to
* @address_msb: Most significant 16-bit word of the address of a
* device to transfer data from/to
* @write_data_lsb: Least significant 16-bit word of the data to be
* written to a device
* @write_data_msb: Most significant 16-bit word of the data to be
* written to a device
* @read_data_lsb: Least significant 16-bit word of the data read
* from a device
* @read_data_msb: Most significant 16-bit word of the data read
* from a device
*/
struct ihs_axi_regs {
u16 interrupt_status;
u16 interrupt_enable_control;
u16 address_lsb;
u16 address_msb;
u16 write_data_lsb;
u16 write_data_msb;
u16 read_data_lsb;
u16 read_data_msb;
};
/**
* ihs_axi_set() - Convenience macro to set values in register map
* @map: The register map to write to
* @member: The member of the ihs_axi_regs structure to write
* @val: The value to write to the register map
*/
#define ihs_axi_set(map, member, val) \
regmap_set(map, struct ihs_axi_regs, member, val)
/**
* ihs_axi_get() - Convenience macro to read values from register map
* @map: The register map to read from
* @member: The member of the ihs_axi_regs structure to read
* @valp: Pointer to a buffer to receive the value read
*/
#define ihs_axi_get(map, member, valp) \
regmap_get(map, struct ihs_axi_regs, member, valp)
/**
* struct ihs_axi_priv - Private data structure of IHS AXI devices
* @map: Register map for the IHS AXI device
*/
struct ihs_axi_priv {
struct regmap *map;
};
/**
* enum status_reg - Description of bits in the interrupt_status register
* @STATUS_READ_COMPLETE_EVENT: A read transfer was completed
* @STATUS_WRITE_COMPLETE_EVENT: A write transfer was completed
* @STATUS_TIMEOUT_EVENT: A timeout has occurred during the transfer
* @STATUS_ERROR_EVENT: A error has occurred during the transfer
* @STATUS_AXI_INT: A AXI interrupt has occurred
* @STATUS_READ_DATA_AVAILABLE: Data is available to be read
* @STATUS_BUSY: The bus is busy
* @STATUS_INIT_DONE: The bus has finished initializing
*/
enum status_reg {
STATUS_READ_COMPLETE_EVENT = BIT(15),
STATUS_WRITE_COMPLETE_EVENT = BIT(14),
STATUS_TIMEOUT_EVENT = BIT(13),
STATUS_ERROR_EVENT = BIT(12),
STATUS_AXI_INT = BIT(11),
STATUS_READ_DATA_AVAILABLE = BIT(7),
STATUS_BUSY = BIT(6),
STATUS_INIT_DONE = BIT(5),
};
/**
* enum control_reg - Description of bit fields in the interrupt_enable_control
* register
* @CONTROL_READ_COMPLETE_EVENT_ENABLE: STATUS_READ_COMPLETE_EVENT will be
* raised in the interrupt_status register
* @CONTROL_WRITE_COMPLETE_EVENT_ENABLE: STATUS_WRITE_COMPLETE_EVENT will be
* raised in the interrupt_status register
* @CONTROL_TIMEOUT_EVENT_ENABLE: STATUS_TIMEOUT_EVENT will be raised in
* the interrupt_status register
* @CONTROL_ERROR_EVENT_ENABLE: STATUS_ERROR_EVENT will be raised in
* the interrupt_status register
* @CONTROL_AXI_INT_ENABLE: STATUS_AXI_INT will be raised in the
* interrupt_status register
* @CONTROL_CMD_NOP: Configure bus to send a NOP command
* for the next transfer
* @CONTROL_CMD_WRITE: Configure bus to do a write transfer
* @CONTROL_CMD_WRITE_POST_INC: Auto-increment address after write
* transfer
* @CONTROL_CMD_READ: Configure bus to do a read transfer
* @CONTROL_CMD_READ_POST_INC: Auto-increment address after read
* transfer
*/
enum control_reg {
CONTROL_READ_COMPLETE_EVENT_ENABLE = BIT(15),
CONTROL_WRITE_COMPLETE_EVENT_ENABLE = BIT(14),
CONTROL_TIMEOUT_EVENT_ENABLE = BIT(13),
CONTROL_ERROR_EVENT_ENABLE = BIT(12),
CONTROL_AXI_INT_ENABLE = BIT(11),
CONTROL_CMD_NOP = 0x0,
CONTROL_CMD_WRITE = 0x8,
CONTROL_CMD_WRITE_POST_INC = 0x9,
CONTROL_CMD_READ = 0xa,
CONTROL_CMD_READ_POST_INC = 0xb,
};
/**
* enum axi_cmd - Determine if transfer is read or write transfer
* @AXI_CMD_READ: The transfer should be a read transfer
* @AXI_CMD_WRITE: The transfer should be a write transfer
*/
enum axi_cmd {
AXI_CMD_READ,
AXI_CMD_WRITE,
};
/**
* ihs_axi_transfer() - Run transfer on the AXI bus
* @bus: The AXI bus device on which to run the transfer on
* @address: The address to use in the transfer (i.e. which address to
* read/write from/to)
* @cmd: Should the transfer be a read or write transfer?
*
* Return: 0 if OK, -ve on error
*/
static int ihs_axi_transfer(struct udevice *bus, ulong address,
enum axi_cmd cmd)
{
struct ihs_axi_priv *priv = dev_get_priv(bus);
/* Try waiting for events up to 10 times */
const uint WAIT_TRIES = 10;
u16 wait_mask = STATUS_TIMEOUT_EVENT |
STATUS_ERROR_EVENT;
u16 complete_flag;
u16 status;
uint k;
if (cmd == AXI_CMD_READ) {
complete_flag = STATUS_READ_COMPLETE_EVENT;
cmd = CONTROL_CMD_READ;
} else {
complete_flag = STATUS_WRITE_COMPLETE_EVENT;
cmd = CONTROL_CMD_WRITE;
}
wait_mask |= complete_flag;
/* Lower 16 bit */
ihs_axi_set(priv->map, address_lsb, address & 0xffff);
/* Upper 16 bit */
ihs_axi_set(priv->map, address_msb, (address >> 16) & 0xffff);
ihs_axi_set(priv->map, interrupt_status, wait_mask);
ihs_axi_set(priv->map, interrupt_enable_control, cmd);
for (k = WAIT_TRIES; k > 0; --k) {
ihs_axi_get(priv->map, interrupt_status, &status);
if (status & wait_mask)
break;
udelay(1);
}
/*
* k == 0 -> Tries ran out with no event we were waiting for actually
* occurring.
*/
if (!k)
ihs_axi_get(priv->map, interrupt_status, &status);
if (status & complete_flag)
return 0;
if (status & STATUS_ERROR_EVENT) {
debug("%s: Error occurred during transfer\n", bus->name);
return -EIO;
}
debug("%s: Transfer timed out\n", bus->name);
return -ETIMEDOUT;
}
/*
* API
*/
static int ihs_axi_read(struct udevice *dev, ulong address, void *data,
enum axi_size_t size)
{
struct ihs_axi_priv *priv = dev_get_priv(dev);
int ret;
u16 data_lsb, data_msb;
u32 *p = data;
if (size != AXI_SIZE_32) {
debug("%s: transfer size '%d' not supported\n",
dev->name, size);
return -ENOSYS;
}
ret = ihs_axi_transfer(dev, address, AXI_CMD_READ);
if (ret < 0) {
debug("%s: Error during AXI transfer (err = %d)\n",
dev->name, ret);
return ret;
}
ihs_axi_get(priv->map, read_data_lsb, &data_lsb);
ihs_axi_get(priv->map, read_data_msb, &data_msb);
/* Assemble data from two 16-bit words */
*p = (data_msb << 16) | data_lsb;
return 0;
}
static int ihs_axi_write(struct udevice *dev, ulong address, void *data,
enum axi_size_t size)
{
struct ihs_axi_priv *priv = dev_get_priv(dev);
int ret;
u32 *p = data;
if (size != AXI_SIZE_32) {
debug("%s: transfer size '%d' not supported\n",
dev->name, size);
return -ENOSYS;
}
/* Lower 16 bit */
ihs_axi_set(priv->map, write_data_lsb, *p & 0xffff);
/* Upper 16 bit */
ihs_axi_set(priv->map, write_data_msb, (*p >> 16) & 0xffff);
ret = ihs_axi_transfer(dev, address, AXI_CMD_WRITE);
if (ret < 0) {
debug("%s: Error during AXI transfer (err = %d)\n",
dev->name, ret);
return ret;
}
return 0;
}
static const struct udevice_id ihs_axi_ids[] = {
{ .compatible = "gdsys,ihs_axi" },
{ /* sentinel */ }
};
static const struct axi_ops ihs_axi_ops = {
.read = ihs_axi_read,
.write = ihs_axi_write,
};
static int ihs_axi_probe(struct udevice *dev)
{
struct ihs_axi_priv *priv = dev_get_priv(dev);
regmap_init_mem(dev_ofnode(dev), &priv->map);
return 0;
}
U_BOOT_DRIVER(ihs_axi_bus) = {
.name = "ihs_axi_bus",
.id = UCLASS_AXI,
.of_match = ihs_axi_ids,
.ops = &ihs_axi_ops,
.priv_auto = sizeof(struct ihs_axi_priv),
.probe = ihs_axi_probe,
};