u-boot/drivers/serial/serial_lpuart.c

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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2019 NXP
* Copyright 2013 Freescale Semiconductor, Inc.
*/
#include <common.h>
#include <clock_legacy.h>
#include <clk.h>
#include <dm.h>
#include <fsl_lpuart.h>
#include <log.h>
#include <watchdog.h>
#include <asm/global_data.h>
#include <asm/io.h>
#include <serial.h>
#include <dm/device_compat.h>
#include <linux/bitops.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_RXFLUSH BIT(14)
#define FIFO_TXFLUSH BIT(15)
#define FIFO_TXSIZE_MASK 0x70
#define FIFO_TXSIZE_OFF 4
#define FIFO_RXSIZE_MASK 0x7
#define FIFO_RXSIZE_OFF 0
#define FIFO_TXFE 0x80
#if defined(CONFIG_ARCH_IMX8) || defined(CONFIG_ARCH_IMXRT)
#define FIFO_RXFE 0x08
#else
#define FIFO_RXFE 0x40
#endif
#define WATER_TXWATER_OFF 0
#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,
DEV_IMX8,
DEV_IMXRT,
};
struct lpuart_serial_plat {
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);
}
}
u32 __weak get_lpuart_clk(void)
{
return get_board_sys_clk();
}
#if CONFIG_IS_ENABLED(CLK)
static int get_lpuart_clk_rate(struct udevice *dev, u32 *clk)
{
struct clk per_clk;
ulong rate;
int ret;
ret = clk_get_by_name(dev, "per", &per_clk);
if (ret) {
dev_err(dev, "Failed to get per clk: %d\n", ret);
return ret;
}
rate = clk_get_rate(&per_clk);
if ((long)rate <= 0) {
dev_err(dev, "Failed to get per clk rate: %ld\n", (long)rate);
return ret;
}
*clk = rate;
return 0;
}
#else
static inline int get_lpuart_clk_rate(struct udevice *dev, u32 *clk)
{ return -ENOSYS; }
#endif
static bool is_lpuart32(struct udevice *dev)
{
struct lpuart_serial_plat *plat = dev_get_plat(dev);
return plat->flags & LPUART_FLAG_REGMAP_32BIT_REG;
}
static void _lpuart_serial_setbrg(struct udevice *dev,
int baudrate)
{
struct lpuart_serial_plat *plat = dev_get_plat(dev);
struct lpuart_fsl *base = plat->reg;
u32 clk;
u16 sbr;
int ret;
if (CONFIG_IS_ENABLED(CLK)) {
ret = get_lpuart_clk_rate(dev, &clk);
if (ret)
return;
} else {
clk = get_lpuart_clk();
}
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_plat *plat)
{
struct lpuart_fsl *base = plat->reg;
if (!(__raw_readb(&base->us1) & (US1_RDRF | US1_OR)))
return -EAGAIN;
barrier();
return __raw_readb(&base->ud);
}
static int _lpuart_serial_putc(struct lpuart_serial_plat *plat,
const char c)
{
struct lpuart_fsl *base = plat->reg;
if (!(__raw_readb(&base->us1) & US1_TDRE))
return -EAGAIN;
__raw_writeb(c, &base->ud);
return 0;
}
/* Test whether a character is in the RX buffer */
static int _lpuart_serial_tstc(struct lpuart_serial_plat *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 udevice *dev)
{
struct lpuart_serial_plat *plat = dev_get_plat(dev);
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(dev, gd->baudrate);
__raw_writeb(UC2_RE | UC2_TE, &base->uc2);
return 0;
}
static void _lpuart32_serial_setbrg_7ulp(struct udevice *dev,
int baudrate)
{
struct lpuart_serial_plat *plat = dev_get_plat(dev);
struct lpuart_fsl_reg32 *base = plat->reg;
u32 sbr, osr, baud_diff, tmp_osr, tmp_sbr, tmp_diff, tmp;
u32 clk;
int ret;
if (CONFIG_IS_ENABLED(CLK)) {
ret = get_lpuart_clk_rate(dev, &clk);
if (ret)
return;
} else {
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 udevice *dev,
int baudrate)
{
struct lpuart_serial_plat *plat = dev_get_plat(dev);
struct lpuart_fsl_reg32 *base = plat->reg;
u32 clk;
u32 sbr;
int ret;
if (CONFIG_IS_ENABLED(CLK)) {
ret = get_lpuart_clk_rate(dev, &clk);
if (ret)
return;
} else {
clk = get_lpuart_clk();
}
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_plat *plat)
{
struct lpuart_fsl_reg32 *base = plat->reg;
u32 stat, val;
lpuart_read32(plat->flags, &base->stat, &stat);
if ((stat & STAT_RDRF) == 0) {
lpuart_write32(plat->flags, &base->stat, STAT_FLAGS);
return -EAGAIN;
}
lpuart_read32(plat->flags, &base->data, &val);
lpuart_read32(plat->flags, &base->stat, &stat);
if (stat & STAT_OR)
lpuart_write32(plat->flags, &base->stat, STAT_OR);
return val & 0x3ff;
}
static int _lpuart32_serial_putc(struct lpuart_serial_plat *plat,
const char c)
{
struct lpuart_fsl_reg32 *base = plat->reg;
u32 stat;
lpuart_read32(plat->flags, &base->stat, &stat);
if (!(stat & STAT_TDRE))
return -EAGAIN;
lpuart_write32(plat->flags, &base->data, c);
return 0;
}
/* Test whether a character is in the RX buffer */
static int _lpuart32_serial_tstc(struct lpuart_serial_plat *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 udevice *dev)
{
struct lpuart_serial_plat *plat = dev_get_plat(dev);
struct lpuart_fsl_reg32 *base = (struct lpuart_fsl_reg32 *)plat->reg;
u32 val, tx_fifo_size;
lpuart_read32(plat->flags, &base->ctrl, &val);
val &= ~CTRL_RE;
val &= ~CTRL_TE;
lpuart_write32(plat->flags, &base->ctrl, val);
lpuart_write32(plat->flags, &base->modir, 0);
lpuart_read32(plat->flags, &base->fifo, &val);
tx_fifo_size = (val & FIFO_TXSIZE_MASK) >> FIFO_TXSIZE_OFF;
/* Set the TX water to half of FIFO size */
if (tx_fifo_size > 1)
tx_fifo_size = tx_fifo_size >> 1;
/* Set RX water to 0, to be triggered by any receive data */
lpuart_write32(plat->flags, &base->water,
(tx_fifo_size << WATER_TXWATER_OFF));
/* Enable TX and RX FIFO */
val |= (FIFO_TXFE | FIFO_RXFE | FIFO_TXFLUSH | FIFO_RXFLUSH);
lpuart_write32(plat->flags, &base->fifo, val);
lpuart_write32(plat->flags, &base->match, 0);
if (plat->devtype == DEV_MX7ULP || plat->devtype == DEV_IMX8 ||
plat->devtype == DEV_IMXRT) {
_lpuart32_serial_setbrg_7ulp(dev, gd->baudrate);
} else {
/* provide data bits, parity, stop bit, etc */
_lpuart32_serial_setbrg(dev, 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_plat *plat = dev_get_plat(dev);
if (is_lpuart32(dev)) {
if (plat->devtype == DEV_MX7ULP || plat->devtype == DEV_IMX8 ||
plat->devtype == DEV_IMXRT)
_lpuart32_serial_setbrg_7ulp(dev, baudrate);
else
_lpuart32_serial_setbrg(dev, baudrate);
} else {
_lpuart_serial_setbrg(dev, baudrate);
}
return 0;
}
static int lpuart_serial_getc(struct udevice *dev)
{
struct lpuart_serial_plat *plat = dev_get_plat(dev);
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_plat *plat = dev_get_plat(dev);
if (is_lpuart32(dev))
return _lpuart32_serial_putc(plat, c);
return _lpuart_serial_putc(plat, c);
}
static int lpuart_serial_pending(struct udevice *dev, bool input)
{
struct lpuart_serial_plat *plat = dev_get_plat(dev);
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)
{
#if CONFIG_IS_ENABLED(CLK)
struct clk per_clk;
int ret;
ret = clk_get_by_name(dev, "per", &per_clk);
if (!ret) {
ret = clk_enable(&per_clk);
if (ret) {
dev_err(dev, "Failed to get per clk: %d\n", ret);
return ret;
}
} else {
debug("%s: Failed to get per clk: %d\n", __func__, ret);
}
#endif
if (is_lpuart32(dev))
return _lpuart32_serial_init(dev);
else
return _lpuart_serial_init(dev);
}
static int lpuart_serial_of_to_plat(struct udevice *dev)
{
struct lpuart_serial_plat *plat = dev_get_plat(dev);
const void *blob = gd->fdt_blob;
int node = dev_of_offset(dev);
fdt_addr_t addr;
addr = dev_read_addr(dev);
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
plat->reg = (void *)addr;
plat->flags = dev_get_driver_data(dev);
if (fdtdec_get_bool(blob, node, "little-endian"))
plat->flags &= ~LPUART_FLAG_REGMAP_ENDIAN_BIG;
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;
else if (!fdt_node_check_compatible(blob, node, "fsl,imx8qm-lpuart"))
plat->devtype = DEV_IMX8;
else if (!fdt_node_check_compatible(blob, node, "fsl,imxrt-lpuart"))
plat->devtype = DEV_IMXRT;
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,ls1028a-lpuart",
.data = LPUART_FLAG_REGMAP_32BIT_REG },
{ .compatible = "fsl,imx7ulp-lpuart",
.data = LPUART_FLAG_REGMAP_32BIT_REG },
{ .compatible = "fsl,vf610-lpuart"},
{ .compatible = "fsl,imx8qm-lpuart",
.data = LPUART_FLAG_REGMAP_32BIT_REG },
{ .compatible = "fsl,imxrt-lpuart",
.data = LPUART_FLAG_REGMAP_32BIT_REG },
{ }
};
U_BOOT_DRIVER(serial_lpuart) = {
.name = "serial_lpuart",
.id = UCLASS_SERIAL,
.of_match = lpuart_serial_ids,
.of_to_plat = lpuart_serial_of_to_plat,
.plat_auto = sizeof(struct lpuart_serial_plat),
.probe = lpuart_serial_probe,
.ops = &lpuart_serial_ops,
};