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u-boot/drivers/serial/ns16550.c
Stefan Roese 6822cf3ec7 serial: ns16550: Add RX interrupt buffer support 
Pasting longer lines into the U-Boot console prompt sometimes leads to
characters missing. One problem here is the small 16-byte FIFO of the
legacy NS16550 UART, e.g. on x86 platforms.

This patch now introduces a Kconfig option to enable RX interrupt
buffer support for NS16550 style UARTs. With this option enabled, I was
able paste really long lines into the U-Boot console, without any
characters missing.

Signed-off-by: Stefan Roese <sr@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Cc: Bin Meng <bmeng.cn@gmail.com>
[trini: Guard ns16550_serial_remove with
CONFIG_IS_ENABLED(SERIAL_PRESENT) to match struct assignment]
Signed-off-by: Tom Rini <trini@konsulko.com>
2017-07-23 17:04:46 -04:00

627 lines
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/*
* COM1 NS16550 support
* originally from linux source (arch/powerpc/boot/ns16550.c)
* modified to use CONFIG_SYS_ISA_MEM and new defines
*/
#include <common.h>
#include <clk.h>
#include <dm.h>
#include <errno.h>
#include <ns16550.h>
#include <serial.h>
#include <watchdog.h>
#include <linux/types.h>
#include <asm/io.h>
DECLARE_GLOBAL_DATA_PTR;
#define UART_LCRVAL UART_LCR_8N1 /* 8 data, 1 stop, no parity */
#define UART_MCRVAL (UART_MCR_DTR | \
UART_MCR_RTS) /* RTS/DTR */
#ifndef CONFIG_DM_SERIAL
#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
#define serial_out(x, y) outb(x, (ulong)y)
#define serial_in(y) inb((ulong)y)
#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE > 0)
#define serial_out(x, y) out_be32(y, x)
#define serial_in(y) in_be32(y)
#elif defined(CONFIG_SYS_NS16550_MEM32) && (CONFIG_SYS_NS16550_REG_SIZE < 0)
#define serial_out(x, y) out_le32(y, x)
#define serial_in(y) in_le32(y)
#else
#define serial_out(x, y) writeb(x, y)
#define serial_in(y) readb(y)
#endif
#endif /* !CONFIG_DM_SERIAL */
#if defined(CONFIG_SOC_KEYSTONE)
#define UART_REG_VAL_PWREMU_MGMT_UART_DISABLE 0
#define UART_REG_VAL_PWREMU_MGMT_UART_ENABLE ((1 << 14) | (1 << 13) | (1 << 0))
#undef UART_MCRVAL
#ifdef CONFIG_SERIAL_HW_FLOW_CONTROL
#define UART_MCRVAL (UART_MCR_RTS | UART_MCR_AFE)
#else
#define UART_MCRVAL (UART_MCR_RTS)
#endif
#endif
#ifndef CONFIG_SYS_NS16550_IER
#define CONFIG_SYS_NS16550_IER 0x00
#endif /* CONFIG_SYS_NS16550_IER */
static inline void serial_out_shift(void *addr, int shift, int value)
{
#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
outb(value, (ulong)addr);
#elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
out_le32(addr, value);
#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
out_be32(addr, value);
#elif defined(CONFIG_SYS_NS16550_MEM32)
writel(value, addr);
#elif defined(CONFIG_SYS_BIG_ENDIAN)
writeb(value, addr + (1 << shift) - 1);
#else
writeb(value, addr);
#endif
}
static inline int serial_in_shift(void *addr, int shift)
{
#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
return inb((ulong)addr);
#elif defined(CONFIG_SYS_NS16550_MEM32) && !defined(CONFIG_SYS_BIG_ENDIAN)
return in_le32(addr);
#elif defined(CONFIG_SYS_NS16550_MEM32) && defined(CONFIG_SYS_BIG_ENDIAN)
return in_be32(addr);
#elif defined(CONFIG_SYS_NS16550_MEM32)
return readl(addr);
#elif defined(CONFIG_SYS_BIG_ENDIAN)
return readb(addr + (1 << shift) - 1);
#else
return readb(addr);
#endif
}
#ifdef CONFIG_DM_SERIAL
#ifndef CONFIG_SYS_NS16550_CLK
#define CONFIG_SYS_NS16550_CLK 0
#endif
static void ns16550_writeb(NS16550_t port, int offset, int value)
{
struct ns16550_platdata *plat = port->plat;
unsigned char *addr;
offset *= 1 << plat->reg_shift;
addr = (unsigned char *)plat->base + offset;
/*
* As far as we know it doesn't make sense to support selection of
* these options at run-time, so use the existing CONFIG options.
*/
serial_out_shift(addr + plat->reg_offset, plat->reg_shift, value);
}
static int ns16550_readb(NS16550_t port, int offset)
{
struct ns16550_platdata *plat = port->plat;
unsigned char *addr;
offset *= 1 << plat->reg_shift;
addr = (unsigned char *)plat->base + offset;
return serial_in_shift(addr + plat->reg_offset, plat->reg_shift);
}
static u32 ns16550_getfcr(NS16550_t port)
{
struct ns16550_platdata *plat = port->plat;
return plat->fcr;
}
/* We can clean these up once everything is moved to driver model */
#define serial_out(value, addr) \
ns16550_writeb(com_port, \
(unsigned char *)addr - (unsigned char *)com_port, value)
#define serial_in(addr) \
ns16550_readb(com_port, \
(unsigned char *)addr - (unsigned char *)com_port)
#else
static u32 ns16550_getfcr(NS16550_t port)
{
return UART_FCR_DEFVAL;
}
#endif
int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
{
const unsigned int mode_x_div = 16;
return DIV_ROUND_CLOSEST(clock, mode_x_div * baudrate);
}
static void NS16550_setbrg(NS16550_t com_port, int baud_divisor)
{
serial_out(UART_LCR_BKSE | UART_LCRVAL, &com_port->lcr);
serial_out(baud_divisor & 0xff, &com_port->dll);
serial_out((baud_divisor >> 8) & 0xff, &com_port->dlm);
serial_out(UART_LCRVAL, &com_port->lcr);
}
void NS16550_init(NS16550_t com_port, int baud_divisor)
{
#if (defined(CONFIG_SPL_BUILD) && \
(defined(CONFIG_OMAP34XX) || defined(CONFIG_OMAP44XX)))
/*
* On some OMAP3/OMAP4 devices when UART3 is configured for boot mode
* before SPL starts only THRE bit is set. We have to empty the
* transmitter before initialization starts.
*/
if ((serial_in(&com_port->lsr) & (UART_LSR_TEMT | UART_LSR_THRE))
== UART_LSR_THRE) {
if (baud_divisor != -1)
NS16550_setbrg(com_port, baud_divisor);
serial_out(0, &com_port->mdr1);
}
#endif
while (!(serial_in(&com_port->lsr) & UART_LSR_TEMT))
;
serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
#if defined(CONFIG_ARCH_OMAP2PLUS)
serial_out(0x7, &com_port->mdr1); /* mode select reset TL16C750*/
#endif
serial_out(UART_MCRVAL, &com_port->mcr);
serial_out(ns16550_getfcr(com_port), &com_port->fcr);
if (baud_divisor != -1)
NS16550_setbrg(com_port, baud_divisor);
#if defined(CONFIG_ARCH_OMAP2PLUS) || defined(CONFIG_SOC_DA8XX)
/* /16 is proper to hit 115200 with 48MHz */
serial_out(0, &com_port->mdr1);
#endif
#if defined(CONFIG_SOC_KEYSTONE)
serial_out(UART_REG_VAL_PWREMU_MGMT_UART_ENABLE, &com_port->regC);
#endif
}
#ifndef CONFIG_NS16550_MIN_FUNCTIONS
void NS16550_reinit(NS16550_t com_port, int baud_divisor)
{
serial_out(CONFIG_SYS_NS16550_IER, &com_port->ier);
NS16550_setbrg(com_port, 0);
serial_out(UART_MCRVAL, &com_port->mcr);
serial_out(ns16550_getfcr(com_port), &com_port->fcr);
NS16550_setbrg(com_port, baud_divisor);
}
#endif /* CONFIG_NS16550_MIN_FUNCTIONS */
void NS16550_putc(NS16550_t com_port, char c)
{
while ((serial_in(&com_port->lsr) & UART_LSR_THRE) == 0)
;
serial_out(c, &com_port->thr);
/*
* Call watchdog_reset() upon newline. This is done here in putc
* since the environment code uses a single puts() to print the complete
* environment upon "printenv". So we can't put this watchdog call
* in puts().
*/
if (c == '\n')
WATCHDOG_RESET();
}
#ifndef CONFIG_NS16550_MIN_FUNCTIONS
char NS16550_getc(NS16550_t com_port)
{
while ((serial_in(&com_port->lsr) & UART_LSR_DR) == 0) {
#if !defined(CONFIG_SPL_BUILD) && defined(CONFIG_USB_TTY)
extern void usbtty_poll(void);
usbtty_poll();
#endif
WATCHDOG_RESET();
}
return serial_in(&com_port->rbr);
}
int NS16550_tstc(NS16550_t com_port)
{
return (serial_in(&com_port->lsr) & UART_LSR_DR) != 0;
}
#endif /* CONFIG_NS16550_MIN_FUNCTIONS */
#ifdef CONFIG_DEBUG_UART_NS16550
#include <debug_uart.h>
static inline void _debug_uart_init(void)
{
struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
int baud_divisor;
/*
* We copy the code from above because it is already horribly messy.
* Trying to refactor to nicely remove the duplication doesn't seem
* feasible. The better fix is to move all users of this driver to
* driver model.
*/
baud_divisor = ns16550_calc_divisor(com_port, CONFIG_DEBUG_UART_CLOCK,
CONFIG_BAUDRATE);
serial_dout(&com_port->ier, CONFIG_SYS_NS16550_IER);
serial_dout(&com_port->mcr, UART_MCRVAL);
serial_dout(&com_port->fcr, UART_FCR_DEFVAL);
serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
serial_dout(&com_port->dll, baud_divisor & 0xff);
serial_dout(&com_port->dlm, (baud_divisor >> 8) & 0xff);
serial_dout(&com_port->lcr, UART_LCRVAL);
}
static inline void _debug_uart_putc(int ch)
{
struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
while (!(serial_din(&com_port->lsr) & UART_LSR_THRE))
;
serial_dout(&com_port->thr, ch);
}
DEBUG_UART_FUNCS
#endif
#ifdef CONFIG_DEBUG_UART_OMAP
#include <debug_uart.h>
static inline void _debug_uart_init(void)
{
struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
int baud_divisor;
baud_divisor = ns16550_calc_divisor(com_port, CONFIG_DEBUG_UART_CLOCK,
CONFIG_BAUDRATE);
serial_dout(&com_port->ier, CONFIG_SYS_NS16550_IER);
serial_dout(&com_port->mdr1, 0x7);
serial_dout(&com_port->mcr, UART_MCRVAL);
serial_dout(&com_port->fcr, UART_FCR_DEFVAL);
serial_dout(&com_port->lcr, UART_LCR_BKSE | UART_LCRVAL);
serial_dout(&com_port->dll, baud_divisor & 0xff);
serial_dout(&com_port->dlm, (baud_divisor >> 8) & 0xff);
serial_dout(&com_port->lcr, UART_LCRVAL);
serial_dout(&com_port->mdr1, 0x0);
}
static inline void _debug_uart_putc(int ch)
{
struct NS16550 *com_port = (struct NS16550 *)CONFIG_DEBUG_UART_BASE;
while (!(serial_din(&com_port->lsr) & UART_LSR_THRE))
;
serial_dout(&com_port->thr, ch);
}
DEBUG_UART_FUNCS
#endif
#ifdef CONFIG_DM_SERIAL
#if CONFIG_IS_ENABLED(SERIAL_IRQ_BUFFER)
#define BUF_COUNT 256
static void rx_fifo_to_buf(struct udevice *dev)
{
struct NS16550 *const com_port = dev_get_priv(dev);
struct ns16550_platdata *plat = dev->platdata;
/* Read all available chars into buffer */
while ((serial_in(&com_port->lsr) & UART_LSR_DR)) {
plat->buf[plat->wr_ptr++] = serial_in(&com_port->rbr);
plat->wr_ptr %= BUF_COUNT;
}
}
static int rx_pending(struct udevice *dev)
{
struct ns16550_platdata *plat = dev->platdata;
/*
* At startup it may happen, that some already received chars are
* "stuck" in the RX FIFO, even with the interrupt enabled. This
* RX FIFO flushing makes sure, that these chars are read out and
* the RX interrupts works as expected.
*/
rx_fifo_to_buf(dev);
return plat->rd_ptr != plat->wr_ptr ? 1 : 0;
}
static int rx_get(struct udevice *dev)
{
struct ns16550_platdata *plat = dev->platdata;
char val;
val = plat->buf[plat->rd_ptr++];
plat->rd_ptr %= BUF_COUNT;
return val;
}
void ns16550_handle_irq(void *data)
{
struct udevice *dev = (struct udevice *)data;
struct NS16550 *const com_port = dev_get_priv(dev);
/* Check if interrupt is pending */
if (serial_in(&com_port->iir) & UART_IIR_NO_INT)
return;
/* Flush all available characters from the RX FIFO into the RX buffer */
rx_fifo_to_buf(dev);
}
#else /* CONFIG_SERIAL_IRQ_BUFFER */
static int rx_pending(struct udevice *dev)
{
struct NS16550 *const com_port = dev_get_priv(dev);
return serial_in(&com_port->lsr) & UART_LSR_DR ? 1 : 0;
}
static int rx_get(struct udevice *dev)
{
struct NS16550 *const com_port = dev_get_priv(dev);
return serial_in(&com_port->rbr);
}
#endif /* CONFIG_SERIAL_IRQ_BUFFER */
static int ns16550_serial_putc(struct udevice *dev, const char ch)
{
struct NS16550 *const com_port = dev_get_priv(dev);
if (!(serial_in(&com_port->lsr) & UART_LSR_THRE))
return -EAGAIN;
serial_out(ch, &com_port->thr);
/*
* Call watchdog_reset() upon newline. This is done here in putc
* since the environment code uses a single puts() to print the complete
* environment upon "printenv". So we can't put this watchdog call
* in puts().
*/
if (ch == '\n')
WATCHDOG_RESET();
return 0;
}
static int ns16550_serial_pending(struct udevice *dev, bool input)
{
struct NS16550 *const com_port = dev_get_priv(dev);
if (input)
return rx_pending(dev);
else
return serial_in(&com_port->lsr) & UART_LSR_THRE ? 0 : 1;
}
static int ns16550_serial_getc(struct udevice *dev)
{
if (!ns16550_serial_pending(dev, true))
return -EAGAIN;
return rx_get(dev);
}
static int ns16550_serial_setbrg(struct udevice *dev, int baudrate)
{
struct NS16550 *const com_port = dev_get_priv(dev);
struct ns16550_platdata *plat = com_port->plat;
int clock_divisor;
clock_divisor = ns16550_calc_divisor(com_port, plat->clock, baudrate);
NS16550_setbrg(com_port, clock_divisor);
return 0;
}
int ns16550_serial_probe(struct udevice *dev)
{
struct NS16550 *const com_port = dev_get_priv(dev);
com_port->plat = dev_get_platdata(dev);
NS16550_init(com_port, -1);
#if CONFIG_IS_ENABLED(SERIAL_IRQ_BUFFER)
if (gd->flags & GD_FLG_RELOC) {
struct ns16550_platdata *plat = dev->platdata;
/* Allocate the RX buffer */
plat->buf = malloc(BUF_COUNT);
/* Install the interrupt handler */
irq_install_handler(plat->irq, ns16550_handle_irq, dev);
/* Enable RX interrupts */
serial_out(UART_IER_RDI, &com_port->ier);
}
#endif
return 0;
}
#if CONFIG_IS_ENABLED(SERIAL_PRESENT) && \
(!defined(CONFIG_TPL_BUILD) || defined(CONFIG_TPL_DM_SERIAL))
static int ns16550_serial_remove(struct udevice *dev)
{
#if CONFIG_IS_ENABLED(SERIAL_IRQ_BUFFER)
if (gd->flags & GD_FLG_RELOC) {
struct ns16550_platdata *plat = dev->platdata;
irq_free_handler(plat->irq);
}
#endif
return 0;
}
#endif
#if CONFIG_IS_ENABLED(OF_CONTROL)
enum {
PORT_NS16550 = 0,
PORT_JZ4780,
};
#endif
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
{
struct ns16550_platdata *plat = dev->platdata;
const u32 port_type = dev_get_driver_data(dev);
fdt_addr_t addr;
struct clk clk;
int err;
/* try Processor Local Bus device first */
addr = dev_read_addr(dev);
#if defined(CONFIG_PCI) && defined(CONFIG_DM_PCI)
if (addr == FDT_ADDR_T_NONE) {
/* then try pci device */
struct fdt_pci_addr pci_addr;
u32 bar;
int ret;
/* we prefer to use a memory-mapped register */
ret = fdtdec_get_pci_addr(gd->fdt_blob, dev_of_offset(dev),
FDT_PCI_SPACE_MEM32, "reg",
&pci_addr);
if (ret) {
/* try if there is any i/o-mapped register */
ret = fdtdec_get_pci_addr(gd->fdt_blob,
dev_of_offset(dev),
FDT_PCI_SPACE_IO,
"reg", &pci_addr);
if (ret)
return ret;
}
ret = fdtdec_get_pci_bar32(dev, &pci_addr, &bar);
if (ret)
return ret;
addr = bar;
}
#endif
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
#ifdef CONFIG_SYS_NS16550_PORT_MAPPED
plat->base = addr;
#else
plat->base = (unsigned long)map_physmem(addr, 0, MAP_NOCACHE);
#endif
plat->reg_offset = dev_read_u32_default(dev, "reg-offset", 0);
plat->reg_shift = dev_read_u32_default(dev, "reg-shift", 0);
err = clk_get_by_index(dev, 0, &clk);
if (!err) {
err = clk_get_rate(&clk);
if (!IS_ERR_VALUE(err))
plat->clock = err;
} else if (err != -ENOENT && err != -ENODEV && err != -ENOSYS) {
debug("ns16550 failed to get clock\n");
return err;
}
if (!plat->clock)
plat->clock = dev_read_u32_default(dev, "clock-frequency",
CONFIG_SYS_NS16550_CLK);
if (!plat->clock) {
debug("ns16550 clock not defined\n");
return -EINVAL;
}
plat->fcr = UART_FCR_DEFVAL;
if (port_type == PORT_JZ4780)
plat->fcr |= UART_FCR_UME;
#if CONFIG_IS_ENABLED(SERIAL_IRQ_BUFFER)
plat->irq = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
"interrupts", 0);
if (!plat->irq) {
debug("ns16550 interrupt not provided\n");
return -EINVAL;
}
#endif
return 0;
}
#endif
const struct dm_serial_ops ns16550_serial_ops = {
.putc = ns16550_serial_putc,
.pending = ns16550_serial_pending,
.getc = ns16550_serial_getc,
.setbrg = ns16550_serial_setbrg,
};
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
/*
* Please consider existing compatible strings before adding a new
* one to keep this table compact. Or you may add a generic "ns16550"
* compatible string to your dts.
*/
static const struct udevice_id ns16550_serial_ids[] = {
{ .compatible = "ns16550", .data = PORT_NS16550 },
{ .compatible = "ns16550a", .data = PORT_NS16550 },
{ .compatible = "ingenic,jz4780-uart", .data = PORT_JZ4780 },
{ .compatible = "nvidia,tegra20-uart", .data = PORT_NS16550 },
{ .compatible = "snps,dw-apb-uart", .data = PORT_NS16550 },
{ .compatible = "ti,omap2-uart", .data = PORT_NS16550 },
{ .compatible = "ti,omap3-uart", .data = PORT_NS16550 },
{ .compatible = "ti,omap4-uart", .data = PORT_NS16550 },
{ .compatible = "ti,am3352-uart", .data = PORT_NS16550 },
{ .compatible = "ti,am4372-uart", .data = PORT_NS16550 },
{ .compatible = "ti,dra742-uart", .data = PORT_NS16550 },
{}
};
#endif /* OF_CONTROL && !OF_PLATDATA */
#if CONFIG_IS_ENABLED(SERIAL_PRESENT)
/* TODO(sjg@chromium.org): Integrate this into a macro like CONFIG_IS_ENABLED */
#if !defined(CONFIG_TPL_BUILD) || defined(CONFIG_TPL_DM_SERIAL)
U_BOOT_DRIVER(ns16550_serial) = {
.name = "ns16550_serial",
.id = UCLASS_SERIAL,
#if CONFIG_IS_ENABLED(OF_CONTROL) && !CONFIG_IS_ENABLED(OF_PLATDATA)
.of_match = ns16550_serial_ids,
.ofdata_to_platdata = ns16550_serial_ofdata_to_platdata,
.platdata_auto_alloc_size = sizeof(struct ns16550_platdata),
#endif
.priv_auto_alloc_size = sizeof(struct NS16550),
.probe = ns16550_serial_probe,
.remove = ns16550_serial_remove,
.ops = &ns16550_serial_ops,
.flags = DM_FLAG_PRE_RELOC,
};
#endif
#endif /* SERIAL_PRESENT */
#endif /* CONFIG_DM_SERIAL */
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