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u-boot/drivers/serial/ns16550.c
Bin Meng 3db886a5bf serial: ns16550: Support ns16550 compatible pci uart devices 
There are many pci uart devices which are ns16550 compatible. We can
describe them in the board dts file and use it as the U-Boot serial
console as specified in the chosen node 'stdout-path' property.

Those pci uart devices can have their register be memory-mapped, or
i/o-mapped. The driver will try to use the memory-mapped register if
the reg property in the node has an entry to describe the memory-mapped
register, otherwise i/o-mapped register will be used.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Acked-by: Simon Glass <sjg@chromium.org>
2015-01-13 07:24:57 -08:00

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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 <dm.h>
#include <errno.h>
#include <fdtdec.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 */
#define UART_FCRVAL (UART_FCR_FIFO_EN | \
UART_FCR_RXSR | \
UART_FCR_TXSR) /* Clear & enable FIFOs */
#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 */
#ifdef CONFIG_DM_SERIAL
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 = map_sysmem(plat->base, 0) + 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.
*/
#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_BIG_ENDIAN)
writeb(value, addr + (1 << plat->reg_shift) - 1);
#else
writeb(value, addr);
#endif
}
static int ns16550_readb(NS16550_t port, int offset)
{
struct ns16550_platdata *plat = port->plat;
unsigned char *addr;
offset *= 1 << plat->reg_shift;
addr = map_sysmem(plat->base, 0) + offset;
#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_BIG_ENDIAN)
return readb(addr + (1 << plat->reg_shift) - 1);
#else
return readb(addr);
#endif
}
/* We can clean these up once everything is moved to driver model */
#define serial_out(value, addr) \
ns16550_writeb(com_port, addr - (unsigned char *)com_port, value)
#define serial_in(addr) \
ns16550_readb(com_port, addr - (unsigned char *)com_port)
#endif
int ns16550_calc_divisor(NS16550_t port, int clock, int baudrate)
{
const unsigned int mode_x_div = 16;
#ifdef CONFIG_OMAP1510
/* If can't cleanly clock 115200 set div to 1 */
if ((clock == 12000000) && (baudrate == 115200)) {
port->osc_12m_sel = OSC_12M_SEL; /* enable 6.5 * divisor */
return 1; /* return 1 for base divisor */
}
port->osc_12m_sel = 0; /* clear if previsouly set */
#endif
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_OMAP) || defined(CONFIG_AM33XX) || \
defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)
serial_out(0x7, &com_port->mdr1); /* mode select reset TL16C750*/
#endif
NS16550_setbrg(com_port, 0);
serial_out(UART_MCRVAL, &com_port->mcr);
serial_out(UART_FCRVAL, &com_port->fcr);
if (baud_divisor != -1)
NS16550_setbrg(com_port, baud_divisor);
#if defined(CONFIG_OMAP) || \
defined(CONFIG_AM33XX) || defined(CONFIG_SOC_DA8XX) || \
defined(CONFIG_TI81XX) || defined(CONFIG_AM43XX)
/* /16 is proper to hit 115200 with 48MHz */
serial_out(0, &com_port->mdr1);
#endif /* CONFIG_OMAP */
#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(UART_FCRVAL, &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_DM_SERIAL
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 serial_in(&com_port->lsr) & UART_LSR_DR ? 1 : 0;
else
return serial_in(&com_port->lsr) & UART_LSR_THRE ? 0 : 1;
}
static int ns16550_serial_getc(struct udevice *dev)
{
struct NS16550 *const com_port = dev_get_priv(dev);
if (!(serial_in(&com_port->lsr) & UART_LSR_DR))
return -EAGAIN;
return serial_in(&com_port->rbr);
}
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);
return 0;
}
#ifdef CONFIG_OF_CONTROL
int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
{
struct ns16550_platdata *plat = dev->platdata;
fdt_addr_t addr;
/* try Processor Local Bus device first */
addr = fdtdec_get_addr(gd->fdt_blob, dev->of_offset, "reg");
#ifdef CONFIG_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,
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,
FDT_PCI_SPACE_IO,
"reg", &pci_addr);
if (ret)
return ret;
}
ret = fdtdec_get_pci_bar32(gd->fdt_blob, dev->of_offset,
&pci_addr, &bar);
if (ret)
return ret;
addr = bar;
}
#endif
if (addr == FDT_ADDR_T_NONE)
return -EINVAL;
plat->base = addr;
plat->reg_shift = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
"reg-shift", 1);
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,
};
#endif /* CONFIG_DM_SERIAL */
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