168 lines
3.7 KiB
C
168 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Driver for FPGA UART
|
|
*
|
|
* Copyright (C) 2022 Intel Corporation.
|
|
*
|
|
* Authors:
|
|
* Ananda Ravuri <ananda.ravuri@intel.com>
|
|
* Matthew Gerlach <matthew.gerlach@linux.intel.com>
|
|
*/
|
|
|
|
#include <linux/bitfield.h>
|
|
#include <linux/device.h>
|
|
#include <linux/dfl.h>
|
|
#include <linux/errno.h>
|
|
#include <linux/ioport.h>
|
|
#include <linux/module.h>
|
|
#include <linux/mod_devicetable.h>
|
|
#include <linux/types.h>
|
|
|
|
#include <linux/serial.h>
|
|
#include <linux/serial_8250.h>
|
|
|
|
#define DFHv1_PARAM_ID_CLK_FRQ 0x2
|
|
#define DFHv1_PARAM_ID_FIFO_LEN 0x3
|
|
|
|
#define DFHv1_PARAM_ID_REG_LAYOUT 0x4
|
|
#define DFHv1_PARAM_REG_LAYOUT_WIDTH GENMASK_ULL(63, 32)
|
|
#define DFHv1_PARAM_REG_LAYOUT_SHIFT GENMASK_ULL(31, 0)
|
|
|
|
struct dfl_uart {
|
|
int line;
|
|
};
|
|
|
|
static int dfh_get_u64_param_val(struct dfl_device *dfl_dev, int param_id, u64 *pval)
|
|
{
|
|
size_t psize;
|
|
u64 *p;
|
|
|
|
p = dfh_find_param(dfl_dev, param_id, &psize);
|
|
if (IS_ERR(p))
|
|
return PTR_ERR(p);
|
|
|
|
if (psize != sizeof(*pval))
|
|
return -EINVAL;
|
|
|
|
*pval = *p;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int dfl_uart_get_params(struct dfl_device *dfl_dev, struct uart_8250_port *uart)
|
|
{
|
|
struct device *dev = &dfl_dev->dev;
|
|
u64 fifo_len, clk_freq, reg_layout;
|
|
u32 reg_width;
|
|
int ret;
|
|
|
|
ret = dfh_get_u64_param_val(dfl_dev, DFHv1_PARAM_ID_CLK_FRQ, &clk_freq);
|
|
if (ret)
|
|
return dev_err_probe(dev, ret, "missing CLK_FRQ param\n");
|
|
|
|
uart->port.uartclk = clk_freq;
|
|
|
|
ret = dfh_get_u64_param_val(dfl_dev, DFHv1_PARAM_ID_FIFO_LEN, &fifo_len);
|
|
if (ret)
|
|
return dev_err_probe(dev, ret, "missing FIFO_LEN param\n");
|
|
|
|
switch (fifo_len) {
|
|
case 32:
|
|
uart->port.type = PORT_ALTR_16550_F32;
|
|
break;
|
|
|
|
case 64:
|
|
uart->port.type = PORT_ALTR_16550_F64;
|
|
break;
|
|
|
|
case 128:
|
|
uart->port.type = PORT_ALTR_16550_F128;
|
|
break;
|
|
|
|
default:
|
|
return dev_err_probe(dev, -EINVAL, "unsupported FIFO_LEN %llu\n", fifo_len);
|
|
}
|
|
|
|
ret = dfh_get_u64_param_val(dfl_dev, DFHv1_PARAM_ID_REG_LAYOUT, ®_layout);
|
|
if (ret)
|
|
return dev_err_probe(dev, ret, "missing REG_LAYOUT param\n");
|
|
|
|
uart->port.regshift = FIELD_GET(DFHv1_PARAM_REG_LAYOUT_SHIFT, reg_layout);
|
|
reg_width = FIELD_GET(DFHv1_PARAM_REG_LAYOUT_WIDTH, reg_layout);
|
|
switch (reg_width) {
|
|
case 4:
|
|
uart->port.iotype = UPIO_MEM32;
|
|
break;
|
|
|
|
case 2:
|
|
uart->port.iotype = UPIO_MEM16;
|
|
break;
|
|
|
|
default:
|
|
return dev_err_probe(dev, -EINVAL, "unsupported reg-width %u\n", reg_width);
|
|
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int dfl_uart_probe(struct dfl_device *dfl_dev)
|
|
{
|
|
struct device *dev = &dfl_dev->dev;
|
|
struct uart_8250_port uart = { };
|
|
struct dfl_uart *dfluart;
|
|
int ret;
|
|
|
|
uart.port.flags = UPF_IOREMAP;
|
|
uart.port.mapbase = dfl_dev->mmio_res.start;
|
|
uart.port.mapsize = resource_size(&dfl_dev->mmio_res);
|
|
|
|
ret = dfl_uart_get_params(dfl_dev, &uart);
|
|
if (ret < 0)
|
|
return dev_err_probe(dev, ret, "failed uart feature walk\n");
|
|
|
|
if (dfl_dev->num_irqs == 1)
|
|
uart.port.irq = dfl_dev->irqs[0];
|
|
|
|
dfluart = devm_kzalloc(dev, sizeof(*dfluart), GFP_KERNEL);
|
|
if (!dfluart)
|
|
return -ENOMEM;
|
|
|
|
dfluart->line = serial8250_register_8250_port(&uart);
|
|
if (dfluart->line < 0)
|
|
return dev_err_probe(dev, dfluart->line, "unable to register 8250 port.\n");
|
|
|
|
dev_set_drvdata(dev, dfluart);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void dfl_uart_remove(struct dfl_device *dfl_dev)
|
|
{
|
|
struct dfl_uart *dfluart = dev_get_drvdata(&dfl_dev->dev);
|
|
|
|
serial8250_unregister_port(dfluart->line);
|
|
}
|
|
|
|
#define FME_FEATURE_ID_UART 0x24
|
|
|
|
static const struct dfl_device_id dfl_uart_ids[] = {
|
|
{ FME_ID, FME_FEATURE_ID_UART },
|
|
{ }
|
|
};
|
|
MODULE_DEVICE_TABLE(dfl, dfl_uart_ids);
|
|
|
|
static struct dfl_driver dfl_uart_driver = {
|
|
.drv = {
|
|
.name = "dfl-uart",
|
|
},
|
|
.id_table = dfl_uart_ids,
|
|
.probe = dfl_uart_probe,
|
|
.remove = dfl_uart_remove,
|
|
};
|
|
module_dfl_driver(dfl_uart_driver);
|
|
|
|
MODULE_DESCRIPTION("DFL Intel UART driver");
|
|
MODULE_AUTHOR("Intel Corporation");
|
|
MODULE_LICENSE("GPL");
|