u-boot/drivers/serial/serial_lpuart.c

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/*
* Copyright 2013 Freescale Semiconductor, Inc.
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <fsl_lpuart.h>
#include <watchdog.h>
#include <asm/io.h>
#include <serial.h>
#include <linux/compiler.h>
#include <asm/arch/imx-regs.h>
#include <asm/arch/clock.h>
#define US1_TDRE (1 << 7)
#define US1_RDRF (1 << 5)
#define US1_OR (1 << 3)
#define UC2_TE (1 << 3)
#define UC2_RE (1 << 2)
#define CFIFO_TXFLUSH (1 << 7)
#define CFIFO_RXFLUSH (1 << 6)
#define SFIFO_RXOF (1 << 2)
#define SFIFO_RXUF (1 << 0)
#define STAT_LBKDIF (1 << 31)
#define STAT_RXEDGIF (1 << 30)
#define STAT_TDRE (1 << 23)
#define STAT_RDRF (1 << 21)
#define STAT_IDLE (1 << 20)
#define STAT_OR (1 << 19)
#define STAT_NF (1 << 18)
#define STAT_FE (1 << 17)
#define STAT_PF (1 << 16)
#define STAT_MA1F (1 << 15)
#define STAT_MA2F (1 << 14)
#define STAT_FLAGS (STAT_LBKDIF | STAT_RXEDGIF | STAT_IDLE | STAT_OR | \
STAT_NF | STAT_FE | STAT_PF | STAT_MA1F | STAT_MA2F)
#define CTRL_TE (1 << 19)
#define CTRL_RE (1 << 18)
#define FIFO_TXFE 0x80
#define FIFO_RXFE 0x40
#define WATER_TXWATER_OFF 1
#define WATER_RXWATER_OFF 16
DECLARE_GLOBAL_DATA_PTR;
#define LPUART_FLAG_REGMAP_32BIT_REG BIT(0)
#define LPUART_FLAG_REGMAP_ENDIAN_BIG BIT(1)
enum lpuart_devtype {
DEV_VF610 = 1,
DEV_LS1021A,
DEV_MX7ULP
};
struct lpuart_serial_platdata {
void *reg;
enum lpuart_devtype devtype;
ulong flags;
};
static void lpuart_read32(u32 flags, u32 *addr, u32 *val)
{
if (flags & LPUART_FLAG_REGMAP_32BIT_REG) {
if (flags & LPUART_FLAG_REGMAP_ENDIAN_BIG)
*(u32 *)val = in_be32(addr);
else
*(u32 *)val = in_le32(addr);
}
}
static void lpuart_write32(u32 flags, u32 *addr, u32 val)
{
if (flags & LPUART_FLAG_REGMAP_32BIT_REG) {
if (flags & LPUART_FLAG_REGMAP_ENDIAN_BIG)
out_be32(addr, val);
else
out_le32(addr, val);
}
}
#ifndef CONFIG_SYS_CLK_FREQ
#define CONFIG_SYS_CLK_FREQ 0
#endif
u32 __weak get_lpuart_clk(void)
{
return CONFIG_SYS_CLK_FREQ;
}
static bool is_lpuart32(struct udevice *dev)
{
struct lpuart_serial_platdata *plat = dev->platdata;
return plat->flags & LPUART_FLAG_REGMAP_32BIT_REG;
}
static void _lpuart_serial_setbrg(struct lpuart_serial_platdata *plat,
int baudrate)
{
struct lpuart_fsl *base = plat->reg;
u32 clk = get_lpuart_clk();
u16 sbr;
sbr = (u16)(clk / (16 * baudrate));
/* place adjustment later - n/32 BRFA */
__raw_writeb(sbr >> 8, &base->ubdh);
__raw_writeb(sbr & 0xff, &base->ubdl);
}
static int _lpuart_serial_getc(struct lpuart_serial_platdata *plat)
{
struct lpuart_fsl *base = plat->reg;
while (!(__raw_readb(&base->us1) & (US1_RDRF | US1_OR)))
WATCHDOG_RESET();
barrier();
return __raw_readb(&base->ud);
}
static void _lpuart_serial_putc(struct lpuart_serial_platdata *plat,
const char c)
{
struct lpuart_fsl *base = plat->reg;
while (!(__raw_readb(&base->us1) & US1_TDRE))
WATCHDOG_RESET();
__raw_writeb(c, &base->ud);
}
/* Test whether a character is in the RX buffer */
static int _lpuart_serial_tstc(struct lpuart_serial_platdata *plat)
{
struct lpuart_fsl *base = plat->reg;
if (__raw_readb(&base->urcfifo) == 0)
return 0;
return 1;
}
/*
* Initialise the serial port with the given baudrate. The settings
* are always 8 data bits, no parity, 1 stop bit, no start bits.
*/
static int _lpuart_serial_init(struct lpuart_serial_platdata *plat)
{
struct lpuart_fsl *base = (struct lpuart_fsl *)plat->reg;
u8 ctrl;
ctrl = __raw_readb(&base->uc2);
ctrl &= ~UC2_RE;
ctrl &= ~UC2_TE;
__raw_writeb(ctrl, &base->uc2);
__raw_writeb(0, &base->umodem);
__raw_writeb(0, &base->uc1);
/* Disable FIFO and flush buffer */
__raw_writeb(0x0, &base->upfifo);
__raw_writeb(0x0, &base->utwfifo);
__raw_writeb(0x1, &base->urwfifo);
__raw_writeb(CFIFO_TXFLUSH | CFIFO_RXFLUSH, &base->ucfifo);
/* provide data bits, parity, stop bit, etc */
_lpuart_serial_setbrg(plat, gd->baudrate);
__raw_writeb(UC2_RE | UC2_TE, &base->uc2);
return 0;
}
static void _lpuart32_serial_setbrg_7ulp(struct lpuart_serial_platdata *plat,
int baudrate)
{
struct lpuart_fsl_reg32 *base = plat->reg;
u32 sbr, osr, baud_diff, tmp_osr, tmp_sbr, tmp_diff, tmp;
u32 clk = get_lpuart_clk();
baud_diff = baudrate;
osr = 0;
sbr = 0;
for (tmp_osr = 4; tmp_osr <= 32; tmp_osr++) {
tmp_sbr = (clk / (baudrate * tmp_osr));
if (tmp_sbr == 0)
tmp_sbr = 1;
/*calculate difference in actual buad w/ current values */
tmp_diff = (clk / (tmp_osr * tmp_sbr));
tmp_diff = tmp_diff - baudrate;
/* select best values between sbr and sbr+1 */
if (tmp_diff > (baudrate - (clk / (tmp_osr * (tmp_sbr + 1))))) {
tmp_diff = baudrate - (clk / (tmp_osr * (tmp_sbr + 1)));
tmp_sbr++;
}
if (tmp_diff <= baud_diff) {
baud_diff = tmp_diff;
osr = tmp_osr;
sbr = tmp_sbr;
}
}
/*
* TODO: handle buadrate outside acceptable rate
* if (baudDiff > ((config->baudRate_Bps / 100) * 3))
* {
* Unacceptable baud rate difference of more than 3%
* return kStatus_LPUART_BaudrateNotSupport;
* }
*/
tmp = in_le32(&base->baud);
if ((osr > 3) && (osr < 8))
tmp |= LPUART_BAUD_BOTHEDGE_MASK;
tmp &= ~LPUART_BAUD_OSR_MASK;
tmp |= LPUART_BAUD_OSR(osr-1);
tmp &= ~LPUART_BAUD_SBR_MASK;
tmp |= LPUART_BAUD_SBR(sbr);
/* explicitly disable 10 bit mode & set 1 stop bit */
tmp &= ~(LPUART_BAUD_M10_MASK | LPUART_BAUD_SBNS_MASK);
out_le32(&base->baud, tmp);
}
static void _lpuart32_serial_setbrg(struct lpuart_serial_platdata *plat,
int baudrate)
{
struct lpuart_fsl_reg32 *base = plat->reg;
u32 clk = get_lpuart_clk();
u32 sbr;
sbr = (clk / (16 * baudrate));
/* place adjustment later - n/32 BRFA */
lpuart_write32(plat->flags, &base->baud, sbr);
}
static int _lpuart32_serial_getc(struct lpuart_serial_platdata *plat)
{
struct lpuart_fsl_reg32 *base = plat->reg;
u32 stat, val;
lpuart_read32(plat->flags, &base->stat, &stat);
while ((stat & STAT_RDRF) == 0) {
lpuart_write32(plat->flags, &base->stat, STAT_FLAGS);
WATCHDOG_RESET();
lpuart_read32(plat->flags, &base->stat, &stat);
}
lpuart_read32(plat->flags, &base->data, &val);
if (plat->devtype & DEV_MX7ULP) {
lpuart_read32(plat->flags, &base->stat, &stat);
if (stat & STAT_OR)
lpuart_write32(plat->flags, &base->stat, STAT_OR);
}
return val & 0x3ff;
}
static void _lpuart32_serial_putc(struct lpuart_serial_platdata *plat,
const char c)
{
struct lpuart_fsl_reg32 *base = plat->reg;
u32 stat;
if (plat->devtype & DEV_MX7ULP) {
if (c == '\n')
serial_putc('\r');
}
while (true) {
lpuart_read32(plat->flags, &base->stat, &stat);
if ((stat & STAT_TDRE))
break;
WATCHDOG_RESET();
}
lpuart_write32(plat->flags, &base->data, c);
}
/* Test whether a character is in the RX buffer */
static int _lpuart32_serial_tstc(struct lpuart_serial_platdata *plat)
{
struct lpuart_fsl_reg32 *base = plat->reg;
u32 water;
lpuart_read32(plat->flags, &base->water, &water);
if ((water >> 24) == 0)
return 0;
return 1;
}
/*
* Initialise the serial port with the given baudrate. The settings
* are always 8 data bits, no parity, 1 stop bit, no start bits.
*/
static int _lpuart32_serial_init(struct lpuart_serial_platdata *plat)
{
struct lpuart_fsl_reg32 *base = (struct lpuart_fsl_reg32 *)plat->reg;
u32 ctrl;
lpuart_read32(plat->flags, &base->ctrl, &ctrl);
ctrl &= ~CTRL_RE;
ctrl &= ~CTRL_TE;
lpuart_write32(plat->flags, &base->ctrl, ctrl);
lpuart_write32(plat->flags, &base->modir, 0);
lpuart_write32(plat->flags, &base->fifo, ~(FIFO_TXFE | FIFO_RXFE));
lpuart_write32(plat->flags, &base->match, 0);
if (plat->devtype & DEV_MX7ULP) {
_lpuart32_serial_setbrg_7ulp(plat, gd->baudrate);
} else {
/* provide data bits, parity, stop bit, etc */
_lpuart32_serial_setbrg(plat, gd->baudrate);
}
lpuart_write32(plat->flags, &base->ctrl, CTRL_RE | CTRL_TE);
return 0;
}
static int lpuart_serial_setbrg(struct udevice *dev, int baudrate)
{
struct lpuart_serial_platdata *plat = dev->platdata;
if (is_lpuart32(dev)) {
if (plat->devtype & DEV_MX7ULP)
_lpuart32_serial_setbrg_7ulp(plat, baudrate);
else
_lpuart32_serial_setbrg(plat, baudrate);
} else {
_lpuart_serial_setbrg(plat, baudrate);
}
return 0;
}
static int lpuart_serial_getc(struct udevice *dev)
{
struct lpuart_serial_platdata *plat = dev->platdata;
if (is_lpuart32(dev))
return _lpuart32_serial_getc(plat);
return _lpuart_serial_getc(plat);
}
static int lpuart_serial_putc(struct udevice *dev, const char c)
{
struct lpuart_serial_platdata *plat = dev->platdata;
if (is_lpuart32(dev))
_lpuart32_serial_putc(plat, c);
else
_lpuart_serial_putc(plat, c);
return 0;
}
static int lpuart_serial_pending(struct udevice *dev, bool input)
{
struct lpuart_serial_platdata *plat = dev->platdata;
struct lpuart_fsl *reg = plat->reg;
struct lpuart_fsl_reg32 *reg32 = plat->reg;
u32 stat;
if (is_lpuart32(dev)) {
if (input) {
return _lpuart32_serial_tstc(plat);
} else {
lpuart_read32(plat->flags, &reg32->stat, &stat);
return stat & STAT_TDRE ? 0 : 1;
}
}
if (input)
return _lpuart_serial_tstc(plat);
else
return __raw_readb(&reg->us1) & US1_TDRE ? 0 : 1;
}
static int lpuart_serial_probe(struct udevice *dev)
{
struct lpuart_serial_platdata *plat = dev->platdata;
if (is_lpuart32(dev))
return _lpuart32_serial_init(plat);
else
return _lpuart_serial_init(plat);
}
static int lpuart_serial_ofdata_to_platdata(struct udevice *dev)
{
struct lpuart_serial_platdata *plat = dev->platdata;
const void *blob = gd->fdt_blob;
int node = dev_of_offset(dev);
fdt_addr_t addr;
addr = devfdt_get_addr(dev);
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
plat->reg = (void *)addr;
plat->flags = dev_get_driver_data(dev);
if (!fdt_node_check_compatible(blob, node, "fsl,ls1021a-lpuart"))
plat->devtype = DEV_LS1021A;
else if (!fdt_node_check_compatible(blob, node, "fsl,imx7ulp-lpuart"))
plat->devtype = DEV_MX7ULP;
else if (!fdt_node_check_compatible(blob, node, "fsl,vf610-lpuart"))
plat->devtype = DEV_VF610;
return 0;
}
static const struct dm_serial_ops lpuart_serial_ops = {
.putc = lpuart_serial_putc,
.pending = lpuart_serial_pending,
.getc = lpuart_serial_getc,
.setbrg = lpuart_serial_setbrg,
};
static const struct udevice_id lpuart_serial_ids[] = {
{ .compatible = "fsl,ls1021a-lpuart", .data =
LPUART_FLAG_REGMAP_32BIT_REG | LPUART_FLAG_REGMAP_ENDIAN_BIG },
{ .compatible = "fsl,imx7ulp-lpuart",
.data = LPUART_FLAG_REGMAP_32BIT_REG },
{ .compatible = "fsl,vf610-lpuart"},
{ }
};
U_BOOT_DRIVER(serial_lpuart) = {
.name = "serial_lpuart",
.id = UCLASS_SERIAL,
.of_match = lpuart_serial_ids,
.ofdata_to_platdata = lpuart_serial_ofdata_to_platdata,
.platdata_auto_alloc_size = sizeof(struct lpuart_serial_platdata),
.probe = lpuart_serial_probe,
.ops = &lpuart_serial_ops,
.flags = DM_FLAG_PRE_RELOC,
};