u-boot/drivers/serial/serial_s5p.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

241 lines
5.1 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2009 SAMSUNG Electronics
* Minkyu Kang <mk7.kang@samsung.com>
* Heungjun Kim <riverful.kim@samsung.com>
*
* based on drivers/serial/s3c64xx.c
*/
#include <common.h>
#include <dm.h>
#include <errno.h>
#include <fdtdec.h>
#include <linux/compiler.h>
#include <asm/io.h>
#include <asm/arch/clk.h>
#include <asm/arch/uart.h>
#include <serial.h>
#include <clk.h>
DECLARE_GLOBAL_DATA_PTR;
#define RX_FIFO_COUNT_SHIFT 0
#define RX_FIFO_COUNT_MASK (0xff << RX_FIFO_COUNT_SHIFT)
#define RX_FIFO_FULL (1 << 8)
#define TX_FIFO_COUNT_SHIFT 16
#define TX_FIFO_COUNT_MASK (0xff << TX_FIFO_COUNT_SHIFT)
#define TX_FIFO_FULL (1 << 24)
/* Information about a serial port */
struct s5p_serial_platdata {
struct s5p_uart *reg; /* address of registers in physical memory */
u8 port_id; /* uart port number */
};
/*
* The coefficient, used to calculate the baudrate on S5P UARTs is
* calculated as
* C = UBRDIV * 16 + number_of_set_bits_in_UDIVSLOT
* however, section 31.6.11 of the datasheet doesn't recomment using 1 for 1,
* 3 for 2, ... (2^n - 1) for n, instead, they suggest using these constants:
*/
static const int udivslot[] = {
0,
0x0080,
0x0808,
0x0888,
0x2222,
0x4924,
0x4a52,
0x54aa,
0x5555,
0xd555,
0xd5d5,
0xddd5,
0xdddd,
0xdfdd,
0xdfdf,
0xffdf,
};
static void __maybe_unused s5p_serial_init(struct s5p_uart *uart)
{
/* enable FIFOs, auto clear Rx FIFO */
writel(0x3, &uart->ufcon);
writel(0, &uart->umcon);
/* 8N1 */
writel(0x3, &uart->ulcon);
/* No interrupts, no DMA, pure polling */
writel(0x245, &uart->ucon);
}
static void __maybe_unused s5p_serial_baud(struct s5p_uart *uart, uint uclk,
int baudrate)
{
u32 val;
val = uclk / baudrate;
writel(val / 16 - 1, &uart->ubrdiv);
if (s5p_uart_divslot())
writew(udivslot[val % 16], &uart->rest.slot);
else
writeb(val % 16, &uart->rest.value);
}
#ifndef CONFIG_SPL_BUILD
int s5p_serial_setbrg(struct udevice *dev, int baudrate)
{
struct s5p_serial_platdata *plat = dev->platdata;
struct s5p_uart *const uart = plat->reg;
u32 uclk;
#ifdef CONFIG_CLK_EXYNOS
struct clk clk;
u32 ret;
ret = clk_get_by_index(dev, 1, &clk);
if (ret < 0)
return ret;
uclk = clk_get_rate(&clk);
#else
uclk = get_uart_clk(plat->port_id);
#endif
s5p_serial_baud(uart, uclk, baudrate);
return 0;
}
static int s5p_serial_probe(struct udevice *dev)
{
struct s5p_serial_platdata *plat = dev->platdata;
struct s5p_uart *const uart = plat->reg;
s5p_serial_init(uart);
return 0;
}
static int serial_err_check(const struct s5p_uart *const uart, int op)
{
unsigned int mask;
/*
* UERSTAT
* Break Detect [3]
* Frame Err [2] : receive operation
* Parity Err [1] : receive operation
* Overrun Err [0] : receive operation
*/
if (op)
mask = 0x8;
else
mask = 0xf;
return readl(&uart->uerstat) & mask;
}
static int s5p_serial_getc(struct udevice *dev)
{
struct s5p_serial_platdata *plat = dev->platdata;
struct s5p_uart *const uart = plat->reg;
if (!(readl(&uart->ufstat) & RX_FIFO_COUNT_MASK))
return -EAGAIN;
serial_err_check(uart, 0);
return (int)(readb(&uart->urxh) & 0xff);
}
static int s5p_serial_putc(struct udevice *dev, const char ch)
{
struct s5p_serial_platdata *plat = dev->platdata;
struct s5p_uart *const uart = plat->reg;
if (readl(&uart->ufstat) & TX_FIFO_FULL)
return -EAGAIN;
writeb(ch, &uart->utxh);
serial_err_check(uart, 1);
return 0;
}
static int s5p_serial_pending(struct udevice *dev, bool input)
{
struct s5p_serial_platdata *plat = dev->platdata;
struct s5p_uart *const uart = plat->reg;
uint32_t ufstat = readl(&uart->ufstat);
if (input)
return (ufstat & RX_FIFO_COUNT_MASK) >> RX_FIFO_COUNT_SHIFT;
else
return (ufstat & TX_FIFO_COUNT_MASK) >> TX_FIFO_COUNT_SHIFT;
}
static int s5p_serial_ofdata_to_platdata(struct udevice *dev)
{
struct s5p_serial_platdata *plat = dev->platdata;
fdt_addr_t addr;
addr = devfdt_get_addr(dev);
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
plat->reg = (struct s5p_uart *)addr;
plat->port_id = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
"id", dev->seq);
return 0;
}
static const struct dm_serial_ops s5p_serial_ops = {
.putc = s5p_serial_putc,
.pending = s5p_serial_pending,
.getc = s5p_serial_getc,
.setbrg = s5p_serial_setbrg,
};
static const struct udevice_id s5p_serial_ids[] = {
{ .compatible = "samsung,exynos4210-uart" },
{ }
};
U_BOOT_DRIVER(serial_s5p) = {
.name = "serial_s5p",
.id = UCLASS_SERIAL,
.of_match = s5p_serial_ids,
.ofdata_to_platdata = s5p_serial_ofdata_to_platdata,
.platdata_auto_alloc_size = sizeof(struct s5p_serial_platdata),
.probe = s5p_serial_probe,
.ops = &s5p_serial_ops,
.flags = DM_FLAG_PRE_RELOC,
};
#endif
#ifdef CONFIG_DEBUG_UART_S5P
#include <debug_uart.h>
static inline void _debug_uart_init(void)
{
struct s5p_uart *uart = (struct s5p_uart *)CONFIG_DEBUG_UART_BASE;
s5p_serial_init(uart);
s5p_serial_baud(uart, CONFIG_DEBUG_UART_CLOCK, CONFIG_BAUDRATE);
}
static inline void _debug_uart_putc(int ch)
{
struct s5p_uart *uart = (struct s5p_uart *)CONFIG_DEBUG_UART_BASE;
while (readl(&uart->ufstat) & TX_FIFO_FULL);
writeb(ch, &uart->utxh);
}
DEBUG_UART_FUNCS
#endif