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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2013, 2014 Antony Pavlov <antonynpavlov@gmail.com>
*
* This file is part of barebox.
*/
#include <common.h>
#include <init.h>
#include <malloc.h>
#include <io.h>
#include <mach/digic/uart.h>
/*
* This driver is based on the "Serial terminal" docs here:
* http://magiclantern.wikia.com/wiki/Register_Map#Misc_Registers
*
* See also disassembler output for Canon A1100IS firmware
* (version a1100_100c):
* * a outc-like function can be found at address 0xffff18f0;
* * a getc-like function can be found at address 0xffff192c.
*/
static inline uint32_t digic_serial_readl(struct console_device *cdev,
uint32_t offset)
{
void __iomem *base = cdev->dev->priv;
return readl(base + offset);
}
static inline void digic_serial_writel(struct console_device *cdev,
uint32_t value, uint32_t offset)
{
void __iomem *base = cdev->dev->priv;
writel(value, base + offset);
}
static int digic_serial_setbaudrate(struct console_device *cdev, int baudrate)
{
/* I don't know how to setup baudrate :( */
return 0;
}
static void digic_serial_putc(struct console_device *cdev, char c)
{
uint32_t status;
do {
status = digic_serial_readl(cdev, DIGIC_UART_ST);
} while (!(status & DIGIC_UART_ST_TX_RDY));
digic_serial_writel(cdev, 0x06, DIGIC_UART_ST);
digic_serial_writel(cdev, c, DIGIC_UART_TX);
}
static int digic_serial_getc(struct console_device *cdev)
{
uint32_t status;
do {
status = digic_serial_readl(cdev, DIGIC_UART_ST);
} while (!(status & DIGIC_UART_ST_RX_RDY));
digic_serial_writel(cdev, 0x01, DIGIC_UART_ST);
return digic_serial_readl(cdev, DIGIC_UART_RX);
}
static int digic_serial_tstc(struct console_device *cdev)
{
uint32_t status = digic_serial_readl(cdev, DIGIC_UART_ST);
return ((status & DIGIC_UART_ST_RX_RDY) != 0);
/*
* Canon folks use additional check, something like this:
*
* if (digic_serial_readl(cdev, DIGIC_UART_ST) & 0x38) {
* digic_serial_writel(cdev, 0x38, DIGIC_UART_ST);
* return 0;
* }
*
* But I know nothing about these magic bits in the status register...
*
*/
}
static int digic_serial_probe(struct device *dev)
{
struct resource *iores;
struct console_device *cdev;
cdev = xzalloc(sizeof(struct console_device));
iores = dev_request_mem_resource(dev, 0);
if (IS_ERR(iores))
return PTR_ERR(iores);
dev->priv = IOMEM(iores->start);
cdev->dev = dev;
cdev->tstc = &digic_serial_tstc;
cdev->putc = &digic_serial_putc;
cdev->getc = &digic_serial_getc;
cdev->setbrg = &digic_serial_setbaudrate;
console_register(cdev);
return 0;
}
static __maybe_unused struct of_device_id digic_serial_dt_ids[] = {
{
.compatible = "canon,digic-uart",
}, {
/* sentinel */
}
};
MODULE_DEVICE_TABLE(of, digic_serial_dt_ids);
static struct driver digic_serial_driver = {
.name = "digic-uart",
.probe = digic_serial_probe,
.of_compatible = DRV_OF_COMPAT(digic_serial_dt_ids),
};
console_platform_driver(digic_serial_driver);
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