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mpc52xx_uart.c
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mpc52xx_uart.c
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/*
* Driver for the PSC of the Freescale MPC52xx PSCs configured as UARTs.
*
* FIXME According to the usermanual the status bits in the status register
* are only updated when the peripherals access the FIFO and not when the
* CPU access them. So since we use this bits to know when we stop writing
* and reading, they may not be updated in-time and a race condition may
* exists. But I haven't be able to prove this and I don't care. But if
* any problem arises, it might worth checking. The TX/RX FIFO Stats
* registers should be used in addition.
* Update: Actually, they seem updated ... At least the bits we use.
*
*
* Maintainer : Sylvain Munaut <[email protected]>
*
* Some of the code has been inspired/copied from the 2.4 code written
* by Dale Farnsworth <[email protected]>.
*
* Copyright (C) 2008 Freescale Semiconductor Inc.
* John Rigby <[email protected]>
* Added support for MPC5121
* Copyright (C) 2006 Secret Lab Technologies Ltd.
* Grant Likely <[email protected]>
* Copyright (C) 2004-2006 Sylvain Munaut <[email protected]>
* Copyright (C) 2003 MontaVista, Software, Inc.
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
/* Platform device Usage :
*
* Since PSCs can have multiple function, the correct driver for each one
* is selected by calling mpc52xx_match_psc_function(...). The function
* handled by this driver is "uart".
*
* The driver init all necessary registers to place the PSC in uart mode without
* DCD. However, the pin multiplexing aren't changed and should be set either
* by the bootloader or in the platform init code.
*
* The idx field must be equal to the PSC index (e.g. 0 for PSC1, 1 for PSC2,
* and so on). So the PSC1 is mapped to /dev/ttyPSC0, PSC2 to /dev/ttyPSC1 and
* so on. But be warned, it's an ABSOLUTE REQUIREMENT ! This is needed mainly
* fpr the console code : without this 1:1 mapping, at early boot time, when we
* are parsing the kernel args console=ttyPSC?, we wouldn't know which PSC it
* will be mapped to.
*/
/* OF Platform device Usage :
*
* This driver is only used for PSCs configured in uart mode. The device
* tree will have a node for each PSC with "mpc52xx-psc-uart" in the compatible
* list.
*
* By default, PSC devices are enumerated in the order they are found. However
* a particular PSC number can be forces by adding 'device_no = <port#>'
* to the device node.
*
* The driver init all necessary registers to place the PSC in uart mode without
* DCD. However, the pin multiplexing aren't changed and should be set either
* by the bootloader or in the platform init code.
*/
#undef DEBUG
#include <linux/device.h>
#include <linux/module.h>
#include <linux/tty.h>
#include <linux/serial.h>
#include <linux/sysrq.h>
#include <linux/console.h>
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <asm/mpc52xx.h>
#include <asm/mpc512x.h>
#include <asm/mpc52xx_psc.h>
#if defined(CONFIG_SERIAL_MPC52xx_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/serial_core.h>
/* We've been assigned a range on the "Low-density serial ports" major */
#define SERIAL_PSC_MAJOR 204
#define SERIAL_PSC_MINOR 148
#define ISR_PASS_LIMIT 256 /* Max number of iteration in the interrupt */
static struct uart_port mpc52xx_uart_ports[MPC52xx_PSC_MAXNUM];
/* Rem: - We use the read_status_mask as a shadow of
* psc->mpc52xx_psc_imr
* - It's important that is array is all zero on start as we
* use it to know if it's initialized or not ! If it's not sure
* it's cleared, then a memset(...,0,...) should be added to
* the console_init
*/
/* lookup table for matching device nodes to index numbers */
static struct device_node *mpc52xx_uart_nodes[MPC52xx_PSC_MAXNUM];
static void mpc52xx_uart_of_enumerate(void);
#define PSC(port) ((struct mpc52xx_psc __iomem *)((port)->membase))
/* Forward declaration of the interruption handling routine */
static irqreturn_t mpc52xx_uart_int(int irq, void *dev_id);
/* Simple macro to test if a port is console or not. This one is taken
* for serial_core.c and maybe should be moved to serial_core.h ? */
#ifdef CONFIG_SERIAL_CORE_CONSOLE
#define uart_console(port) \
((port)->cons && (port)->cons->index == (port)->line)
#else
#define uart_console(port) (0)
#endif
/* ======================================================================== */
/* PSC fifo operations for isolating differences between 52xx and 512x */
/* ======================================================================== */
struct psc_ops {
void (*fifo_init)(struct uart_port *port);
int (*raw_rx_rdy)(struct uart_port *port);
int (*raw_tx_rdy)(struct uart_port *port);
int (*rx_rdy)(struct uart_port *port);
int (*tx_rdy)(struct uart_port *port);
int (*tx_empty)(struct uart_port *port);
void (*stop_rx)(struct uart_port *port);
void (*start_tx)(struct uart_port *port);
void (*stop_tx)(struct uart_port *port);
void (*rx_clr_irq)(struct uart_port *port);
void (*tx_clr_irq)(struct uart_port *port);
void (*write_char)(struct uart_port *port, unsigned char c);
unsigned char (*read_char)(struct uart_port *port);
void (*cw_disable_ints)(struct uart_port *port);
void (*cw_restore_ints)(struct uart_port *port);
unsigned long (*getuartclk)(void *p);
};
#ifdef CONFIG_PPC_MPC52xx
#define FIFO_52xx(port) ((struct mpc52xx_psc_fifo __iomem *)(PSC(port)+1))
static void mpc52xx_psc_fifo_init(struct uart_port *port)
{
struct mpc52xx_psc __iomem *psc = PSC(port);
struct mpc52xx_psc_fifo __iomem *fifo = FIFO_52xx(port);
/* /32 prescaler */
out_be16(&psc->mpc52xx_psc_clock_select, 0xdd00);
out_8(&fifo->rfcntl, 0x00);
out_be16(&fifo->rfalarm, 0x1ff);
out_8(&fifo->tfcntl, 0x07);
out_be16(&fifo->tfalarm, 0x80);
port->read_status_mask |= MPC52xx_PSC_IMR_RXRDY | MPC52xx_PSC_IMR_TXRDY;
out_be16(&psc->mpc52xx_psc_imr, port->read_status_mask);
}
static int mpc52xx_psc_raw_rx_rdy(struct uart_port *port)
{
return in_be16(&PSC(port)->mpc52xx_psc_status)
& MPC52xx_PSC_SR_RXRDY;
}
static int mpc52xx_psc_raw_tx_rdy(struct uart_port *port)
{
return in_be16(&PSC(port)->mpc52xx_psc_status)
& MPC52xx_PSC_SR_TXRDY;
}
static int mpc52xx_psc_rx_rdy(struct uart_port *port)
{
return in_be16(&PSC(port)->mpc52xx_psc_isr)
& port->read_status_mask
& MPC52xx_PSC_IMR_RXRDY;
}
static int mpc52xx_psc_tx_rdy(struct uart_port *port)
{
return in_be16(&PSC(port)->mpc52xx_psc_isr)
& port->read_status_mask
& MPC52xx_PSC_IMR_TXRDY;
}
static int mpc52xx_psc_tx_empty(struct uart_port *port)
{
return in_be16(&PSC(port)->mpc52xx_psc_status)
& MPC52xx_PSC_SR_TXEMP;
}
static void mpc52xx_psc_start_tx(struct uart_port *port)
{
port->read_status_mask |= MPC52xx_PSC_IMR_TXRDY;
out_be16(&PSC(port)->mpc52xx_psc_imr, port->read_status_mask);
}
static void mpc52xx_psc_stop_tx(struct uart_port *port)
{
port->read_status_mask &= ~MPC52xx_PSC_IMR_TXRDY;
out_be16(&PSC(port)->mpc52xx_psc_imr, port->read_status_mask);
}
static void mpc52xx_psc_stop_rx(struct uart_port *port)
{
port->read_status_mask &= ~MPC52xx_PSC_IMR_RXRDY;
out_be16(&PSC(port)->mpc52xx_psc_imr, port->read_status_mask);
}
static void mpc52xx_psc_rx_clr_irq(struct uart_port *port)
{
}
static void mpc52xx_psc_tx_clr_irq(struct uart_port *port)
{
}
static void mpc52xx_psc_write_char(struct uart_port *port, unsigned char c)
{
out_8(&PSC(port)->mpc52xx_psc_buffer_8, c);
}
static unsigned char mpc52xx_psc_read_char(struct uart_port *port)
{
return in_8(&PSC(port)->mpc52xx_psc_buffer_8);
}
static void mpc52xx_psc_cw_disable_ints(struct uart_port *port)
{
out_be16(&PSC(port)->mpc52xx_psc_imr, 0);
}
static void mpc52xx_psc_cw_restore_ints(struct uart_port *port)
{
out_be16(&PSC(port)->mpc52xx_psc_imr, port->read_status_mask);
}
/* Search for bus-frequency property in this node or a parent */
static unsigned long mpc52xx_getuartclk(void *p)
{
/*
* 5200 UARTs have a / 32 prescaler
* but the generic serial code assumes 16
* so return ipb freq / 2
*/
return mpc52xx_find_ipb_freq(p) / 2;
}
static struct psc_ops mpc52xx_psc_ops = {
.fifo_init = mpc52xx_psc_fifo_init,
.raw_rx_rdy = mpc52xx_psc_raw_rx_rdy,
.raw_tx_rdy = mpc52xx_psc_raw_tx_rdy,
.rx_rdy = mpc52xx_psc_rx_rdy,
.tx_rdy = mpc52xx_psc_tx_rdy,
.tx_empty = mpc52xx_psc_tx_empty,
.stop_rx = mpc52xx_psc_stop_rx,
.start_tx = mpc52xx_psc_start_tx,
.stop_tx = mpc52xx_psc_stop_tx,
.rx_clr_irq = mpc52xx_psc_rx_clr_irq,
.tx_clr_irq = mpc52xx_psc_tx_clr_irq,
.write_char = mpc52xx_psc_write_char,
.read_char = mpc52xx_psc_read_char,
.cw_disable_ints = mpc52xx_psc_cw_disable_ints,
.cw_restore_ints = mpc52xx_psc_cw_restore_ints,
.getuartclk = mpc52xx_getuartclk,
};
#endif /* CONFIG_MPC52xx */
#ifdef CONFIG_PPC_MPC512x
#define FIFO_512x(port) ((struct mpc512x_psc_fifo __iomem *)(PSC(port)+1))
static void mpc512x_psc_fifo_init(struct uart_port *port)
{
out_be32(&FIFO_512x(port)->txcmd, MPC512x_PSC_FIFO_RESET_SLICE);
out_be32(&FIFO_512x(port)->txcmd, MPC512x_PSC_FIFO_ENABLE_SLICE);
out_be32(&FIFO_512x(port)->txalarm, 1);
out_be32(&FIFO_512x(port)->tximr, 0);
out_be32(&FIFO_512x(port)->rxcmd, MPC512x_PSC_FIFO_RESET_SLICE);
out_be32(&FIFO_512x(port)->rxcmd, MPC512x_PSC_FIFO_ENABLE_SLICE);
out_be32(&FIFO_512x(port)->rxalarm, 1);
out_be32(&FIFO_512x(port)->rximr, 0);
out_be32(&FIFO_512x(port)->tximr, MPC512x_PSC_FIFO_ALARM);
out_be32(&FIFO_512x(port)->rximr, MPC512x_PSC_FIFO_ALARM);
}
static int mpc512x_psc_raw_rx_rdy(struct uart_port *port)
{
return !(in_be32(&FIFO_512x(port)->rxsr) & MPC512x_PSC_FIFO_EMPTY);
}
static int mpc512x_psc_raw_tx_rdy(struct uart_port *port)
{
return !(in_be32(&FIFO_512x(port)->txsr) & MPC512x_PSC_FIFO_FULL);
}
static int mpc512x_psc_rx_rdy(struct uart_port *port)
{
return in_be32(&FIFO_512x(port)->rxsr)
& in_be32(&FIFO_512x(port)->rximr)
& MPC512x_PSC_FIFO_ALARM;
}
static int mpc512x_psc_tx_rdy(struct uart_port *port)
{
return in_be32(&FIFO_512x(port)->txsr)
& in_be32(&FIFO_512x(port)->tximr)
& MPC512x_PSC_FIFO_ALARM;
}
static int mpc512x_psc_tx_empty(struct uart_port *port)
{
return in_be32(&FIFO_512x(port)->txsr)
& MPC512x_PSC_FIFO_EMPTY;
}
static void mpc512x_psc_stop_rx(struct uart_port *port)
{
unsigned long rx_fifo_imr;
rx_fifo_imr = in_be32(&FIFO_512x(port)->rximr);
rx_fifo_imr &= ~MPC512x_PSC_FIFO_ALARM;
out_be32(&FIFO_512x(port)->rximr, rx_fifo_imr);
}
static void mpc512x_psc_start_tx(struct uart_port *port)
{
unsigned long tx_fifo_imr;
tx_fifo_imr = in_be32(&FIFO_512x(port)->tximr);
tx_fifo_imr |= MPC512x_PSC_FIFO_ALARM;
out_be32(&FIFO_512x(port)->tximr, tx_fifo_imr);
}
static void mpc512x_psc_stop_tx(struct uart_port *port)
{
unsigned long tx_fifo_imr;
tx_fifo_imr = in_be32(&FIFO_512x(port)->tximr);
tx_fifo_imr &= ~MPC512x_PSC_FIFO_ALARM;
out_be32(&FIFO_512x(port)->tximr, tx_fifo_imr);
}
static void mpc512x_psc_rx_clr_irq(struct uart_port *port)
{
out_be32(&FIFO_512x(port)->rxisr, in_be32(&FIFO_512x(port)->rxisr));
}
static void mpc512x_psc_tx_clr_irq(struct uart_port *port)
{
out_be32(&FIFO_512x(port)->txisr, in_be32(&FIFO_512x(port)->txisr));
}
static void mpc512x_psc_write_char(struct uart_port *port, unsigned char c)
{
out_8(&FIFO_512x(port)->txdata_8, c);
}
static unsigned char mpc512x_psc_read_char(struct uart_port *port)
{
return in_8(&FIFO_512x(port)->rxdata_8);
}
static void mpc512x_psc_cw_disable_ints(struct uart_port *port)
{
port->read_status_mask =
in_be32(&FIFO_512x(port)->tximr) << 16 |
in_be32(&FIFO_512x(port)->rximr);
out_be32(&FIFO_512x(port)->tximr, 0);
out_be32(&FIFO_512x(port)->rximr, 0);
}
static void mpc512x_psc_cw_restore_ints(struct uart_port *port)
{
out_be32(&FIFO_512x(port)->tximr,
(port->read_status_mask >> 16) & 0x7f);
out_be32(&FIFO_512x(port)->rximr, port->read_status_mask & 0x7f);
}
static unsigned long mpc512x_getuartclk(void *p)
{
return mpc512x_find_ips_freq(p);
}
static struct psc_ops mpc512x_psc_ops = {
.fifo_init = mpc512x_psc_fifo_init,
.raw_rx_rdy = mpc512x_psc_raw_rx_rdy,
.raw_tx_rdy = mpc512x_psc_raw_tx_rdy,
.rx_rdy = mpc512x_psc_rx_rdy,
.tx_rdy = mpc512x_psc_tx_rdy,
.tx_empty = mpc512x_psc_tx_empty,
.stop_rx = mpc512x_psc_stop_rx,
.start_tx = mpc512x_psc_start_tx,
.stop_tx = mpc512x_psc_stop_tx,
.rx_clr_irq = mpc512x_psc_rx_clr_irq,
.tx_clr_irq = mpc512x_psc_tx_clr_irq,
.write_char = mpc512x_psc_write_char,
.read_char = mpc512x_psc_read_char,
.cw_disable_ints = mpc512x_psc_cw_disable_ints,
.cw_restore_ints = mpc512x_psc_cw_restore_ints,
.getuartclk = mpc512x_getuartclk,
};
#endif
static struct psc_ops *psc_ops;
/* ======================================================================== */
/* UART operations */
/* ======================================================================== */
static unsigned int
mpc52xx_uart_tx_empty(struct uart_port *port)
{
return psc_ops->tx_empty(port) ? TIOCSER_TEMT : 0;
}
static void
mpc52xx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
if (mctrl & TIOCM_RTS)
out_8(&PSC(port)->op1, MPC52xx_PSC_OP_RTS);
else
out_8(&PSC(port)->op0, MPC52xx_PSC_OP_RTS);
}
static unsigned int
mpc52xx_uart_get_mctrl(struct uart_port *port)
{
unsigned int ret = TIOCM_DSR;
u8 status = in_8(&PSC(port)->mpc52xx_psc_ipcr);
if (!(status & MPC52xx_PSC_CTS))
ret |= TIOCM_CTS;
if (!(status & MPC52xx_PSC_DCD))
ret |= TIOCM_CAR;
return ret;
}
static void
mpc52xx_uart_stop_tx(struct uart_port *port)
{
/* port->lock taken by caller */
psc_ops->stop_tx(port);
}
static void
mpc52xx_uart_start_tx(struct uart_port *port)
{
/* port->lock taken by caller */
psc_ops->start_tx(port);
}
static void
mpc52xx_uart_send_xchar(struct uart_port *port, char ch)
{
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
port->x_char = ch;
if (ch) {
/* Make sure tx interrupts are on */
/* Truly necessary ??? They should be anyway */
psc_ops->start_tx(port);
}
spin_unlock_irqrestore(&port->lock, flags);
}
static void
mpc52xx_uart_stop_rx(struct uart_port *port)
{
/* port->lock taken by caller */
psc_ops->stop_rx(port);
}
static void
mpc52xx_uart_enable_ms(struct uart_port *port)
{
struct mpc52xx_psc __iomem *psc = PSC(port);
/* clear D_*-bits by reading them */
in_8(&psc->mpc52xx_psc_ipcr);
/* enable CTS and DCD as IPC interrupts */
out_8(&psc->mpc52xx_psc_acr, MPC52xx_PSC_IEC_CTS | MPC52xx_PSC_IEC_DCD);
port->read_status_mask |= MPC52xx_PSC_IMR_IPC;
out_be16(&psc->mpc52xx_psc_imr, port->read_status_mask);
}
static void
mpc52xx_uart_break_ctl(struct uart_port *port, int ctl)
{
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
if (ctl == -1)
out_8(&PSC(port)->command, MPC52xx_PSC_START_BRK);
else
out_8(&PSC(port)->command, MPC52xx_PSC_STOP_BRK);
spin_unlock_irqrestore(&port->lock, flags);
}
static int
mpc52xx_uart_startup(struct uart_port *port)
{
struct mpc52xx_psc __iomem *psc = PSC(port);
int ret;
/* Request IRQ */
ret = request_irq(port->irq, mpc52xx_uart_int,
IRQF_DISABLED | IRQF_SAMPLE_RANDOM,
"mpc52xx_psc_uart", port);
if (ret)
return ret;
/* Reset/activate the port, clear and enable interrupts */
out_8(&psc->command, MPC52xx_PSC_RST_RX);
out_8(&psc->command, MPC52xx_PSC_RST_TX);
out_be32(&psc->sicr, 0); /* UART mode DCD ignored */
psc_ops->fifo_init(port);
out_8(&psc->command, MPC52xx_PSC_TX_ENABLE);
out_8(&psc->command, MPC52xx_PSC_RX_ENABLE);
return 0;
}
static void
mpc52xx_uart_shutdown(struct uart_port *port)
{
struct mpc52xx_psc __iomem *psc = PSC(port);
/* Shut down the port. Leave TX active if on a console port */
out_8(&psc->command, MPC52xx_PSC_RST_RX);
if (!uart_console(port))
out_8(&psc->command, MPC52xx_PSC_RST_TX);
port->read_status_mask = 0;
out_be16(&psc->mpc52xx_psc_imr, port->read_status_mask);
/* Release interrupt */
free_irq(port->irq, port);
}
static void
mpc52xx_uart_set_termios(struct uart_port *port, struct ktermios *new,
struct ktermios *old)
{
struct mpc52xx_psc __iomem *psc = PSC(port);
unsigned long flags;
unsigned char mr1, mr2;
unsigned short ctr;
unsigned int j, baud, quot;
/* Prepare what we're gonna write */
mr1 = 0;
switch (new->c_cflag & CSIZE) {
case CS5: mr1 |= MPC52xx_PSC_MODE_5_BITS;
break;
case CS6: mr1 |= MPC52xx_PSC_MODE_6_BITS;
break;
case CS7: mr1 |= MPC52xx_PSC_MODE_7_BITS;
break;
case CS8:
default: mr1 |= MPC52xx_PSC_MODE_8_BITS;
}
if (new->c_cflag & PARENB) {
mr1 |= (new->c_cflag & PARODD) ?
MPC52xx_PSC_MODE_PARODD : MPC52xx_PSC_MODE_PAREVEN;
} else
mr1 |= MPC52xx_PSC_MODE_PARNONE;
mr2 = 0;
if (new->c_cflag & CSTOPB)
mr2 |= MPC52xx_PSC_MODE_TWO_STOP;
else
mr2 |= ((new->c_cflag & CSIZE) == CS5) ?
MPC52xx_PSC_MODE_ONE_STOP_5_BITS :
MPC52xx_PSC_MODE_ONE_STOP;
if (new->c_cflag & CRTSCTS) {
mr1 |= MPC52xx_PSC_MODE_RXRTS;
mr2 |= MPC52xx_PSC_MODE_TXCTS;
}
baud = uart_get_baud_rate(port, new, old, 0, port->uartclk/16);
quot = uart_get_divisor(port, baud);
ctr = quot & 0xffff;
/* Get the lock */
spin_lock_irqsave(&port->lock, flags);
/* Update the per-port timeout */
uart_update_timeout(port, new->c_cflag, baud);
/* Do our best to flush TX & RX, so we don't lose anything */
/* But we don't wait indefinitely ! */
j = 5000000; /* Maximum wait */
/* FIXME Can't receive chars since set_termios might be called at early
* boot for the console, all stuff is not yet ready to receive at that
* time and that just makes the kernel oops */
/* while (j-- && mpc52xx_uart_int_rx_chars(port)); */
while (!mpc52xx_uart_tx_empty(port) && --j)
udelay(1);
if (!j)
printk(KERN_ERR "mpc52xx_uart.c: "
"Unable to flush RX & TX fifos in-time in set_termios."
"Some chars may have been lost.\n");
/* Reset the TX & RX */
out_8(&psc->command, MPC52xx_PSC_RST_RX);
out_8(&psc->command, MPC52xx_PSC_RST_TX);
/* Send new mode settings */
out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
out_8(&psc->mode, mr1);
out_8(&psc->mode, mr2);
out_8(&psc->ctur, ctr >> 8);
out_8(&psc->ctlr, ctr & 0xff);
if (UART_ENABLE_MS(port, new->c_cflag))
mpc52xx_uart_enable_ms(port);
/* Reenable TX & RX */
out_8(&psc->command, MPC52xx_PSC_TX_ENABLE);
out_8(&psc->command, MPC52xx_PSC_RX_ENABLE);
/* We're all set, release the lock */
spin_unlock_irqrestore(&port->lock, flags);
}
static const char *
mpc52xx_uart_type(struct uart_port *port)
{
return port->type == PORT_MPC52xx ? "MPC52xx PSC" : NULL;
}
static void
mpc52xx_uart_release_port(struct uart_port *port)
{
/* remapped by us ? */
if (port->flags & UPF_IOREMAP) {
iounmap(port->membase);
port->membase = NULL;
}
release_mem_region(port->mapbase, sizeof(struct mpc52xx_psc));
}
static int
mpc52xx_uart_request_port(struct uart_port *port)
{
int err;
if (port->flags & UPF_IOREMAP) /* Need to remap ? */
port->membase = ioremap(port->mapbase,
sizeof(struct mpc52xx_psc));
if (!port->membase)
return -EINVAL;
err = request_mem_region(port->mapbase, sizeof(struct mpc52xx_psc),
"mpc52xx_psc_uart") != NULL ? 0 : -EBUSY;
if (err && (port->flags & UPF_IOREMAP)) {
iounmap(port->membase);
port->membase = NULL;
}
return err;
}
static void
mpc52xx_uart_config_port(struct uart_port *port, int flags)
{
if ((flags & UART_CONFIG_TYPE)
&& (mpc52xx_uart_request_port(port) == 0))
port->type = PORT_MPC52xx;
}
static int
mpc52xx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
{
if (ser->type != PORT_UNKNOWN && ser->type != PORT_MPC52xx)
return -EINVAL;
if ((ser->irq != port->irq) ||
(ser->io_type != SERIAL_IO_MEM) ||
(ser->baud_base != port->uartclk) ||
(ser->iomem_base != (void *)port->mapbase) ||
(ser->hub6 != 0))
return -EINVAL;
return 0;
}
static struct uart_ops mpc52xx_uart_ops = {
.tx_empty = mpc52xx_uart_tx_empty,
.set_mctrl = mpc52xx_uart_set_mctrl,
.get_mctrl = mpc52xx_uart_get_mctrl,
.stop_tx = mpc52xx_uart_stop_tx,
.start_tx = mpc52xx_uart_start_tx,
.send_xchar = mpc52xx_uart_send_xchar,
.stop_rx = mpc52xx_uart_stop_rx,
.enable_ms = mpc52xx_uart_enable_ms,
.break_ctl = mpc52xx_uart_break_ctl,
.startup = mpc52xx_uart_startup,
.shutdown = mpc52xx_uart_shutdown,
.set_termios = mpc52xx_uart_set_termios,
/* .pm = mpc52xx_uart_pm, Not supported yet */
/* .set_wake = mpc52xx_uart_set_wake, Not supported yet */
.type = mpc52xx_uart_type,
.release_port = mpc52xx_uart_release_port,
.request_port = mpc52xx_uart_request_port,
.config_port = mpc52xx_uart_config_port,
.verify_port = mpc52xx_uart_verify_port
};
/* ======================================================================== */
/* Interrupt handling */
/* ======================================================================== */
static inline int
mpc52xx_uart_int_rx_chars(struct uart_port *port)
{
struct tty_struct *tty = port->info->port.tty;
unsigned char ch, flag;
unsigned short status;
/* While we can read, do so ! */
while (psc_ops->raw_rx_rdy(port)) {
/* Get the char */
ch = psc_ops->read_char(port);
/* Handle sysreq char */
#ifdef SUPPORT_SYSRQ
if (uart_handle_sysrq_char(port, ch)) {
port->sysrq = 0;
continue;
}
#endif
/* Store it */
flag = TTY_NORMAL;
port->icount.rx++;
status = in_be16(&PSC(port)->mpc52xx_psc_status);
if (status & (MPC52xx_PSC_SR_PE |
MPC52xx_PSC_SR_FE |
MPC52xx_PSC_SR_RB)) {
if (status & MPC52xx_PSC_SR_RB) {
flag = TTY_BREAK;
uart_handle_break(port);
port->icount.brk++;
} else if (status & MPC52xx_PSC_SR_PE) {
flag = TTY_PARITY;
port->icount.parity++;
}
else if (status & MPC52xx_PSC_SR_FE) {
flag = TTY_FRAME;
port->icount.frame++;
}
/* Clear error condition */
out_8(&PSC(port)->command, MPC52xx_PSC_RST_ERR_STAT);
}
tty_insert_flip_char(tty, ch, flag);
if (status & MPC52xx_PSC_SR_OE) {
/*
* Overrun is special, since it's
* reported immediately, and doesn't
* affect the current character
*/
tty_insert_flip_char(tty, 0, TTY_OVERRUN);
port->icount.overrun++;
}
}
spin_unlock(&port->lock);
tty_flip_buffer_push(tty);
spin_lock(&port->lock);
return psc_ops->raw_rx_rdy(port);
}
static inline int
mpc52xx_uart_int_tx_chars(struct uart_port *port)
{
struct circ_buf *xmit = &port->info->xmit;
/* Process out of band chars */
if (port->x_char) {
psc_ops->write_char(port, port->x_char);
port->icount.tx++;
port->x_char = 0;
return 1;
}
/* Nothing to do ? */
if (uart_circ_empty(xmit) || uart_tx_stopped(port)) {
mpc52xx_uart_stop_tx(port);
return 0;
}
/* Send chars */
while (psc_ops->raw_tx_rdy(port)) {
psc_ops->write_char(port, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
if (uart_circ_empty(xmit))
break;
}
/* Wake up */
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
/* Maybe we're done after all */
if (uart_circ_empty(xmit)) {
mpc52xx_uart_stop_tx(port);
return 0;
}
return 1;
}
static irqreturn_t
mpc52xx_uart_int(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
unsigned long pass = ISR_PASS_LIMIT;
unsigned int keepgoing;
u8 status;
spin_lock(&port->lock);
/* While we have stuff to do, we continue */
do {
/* If we don't find anything to do, we stop */
keepgoing = 0;
psc_ops->rx_clr_irq(port);
if (psc_ops->rx_rdy(port))
keepgoing |= mpc52xx_uart_int_rx_chars(port);
psc_ops->tx_clr_irq(port);
if (psc_ops->tx_rdy(port))
keepgoing |= mpc52xx_uart_int_tx_chars(port);
status = in_8(&PSC(port)->mpc52xx_psc_ipcr);
if (status & MPC52xx_PSC_D_DCD)
uart_handle_dcd_change(port, !(status & MPC52xx_PSC_DCD));
if (status & MPC52xx_PSC_D_CTS)
uart_handle_cts_change(port, !(status & MPC52xx_PSC_CTS));
/* Limit number of iteration */
if (!(--pass))
keepgoing = 0;
} while (keepgoing);
spin_unlock(&port->lock);
return IRQ_HANDLED;
}
/* ======================================================================== */
/* Console ( if applicable ) */
/* ======================================================================== */
#ifdef CONFIG_SERIAL_MPC52xx_CONSOLE
static void __init
mpc52xx_console_get_options(struct uart_port *port,
int *baud, int *parity, int *bits, int *flow)
{
struct mpc52xx_psc __iomem *psc = PSC(port);
unsigned char mr1;
pr_debug("mpc52xx_console_get_options(port=%p)\n", port);
/* Read the mode registers */
out_8(&psc->command, MPC52xx_PSC_SEL_MODE_REG_1);
mr1 = in_8(&psc->mode);
/* CT{U,L}R are write-only ! */
*baud = CONFIG_SERIAL_MPC52xx_CONSOLE_BAUD;
/* Parse them */
switch (mr1 & MPC52xx_PSC_MODE_BITS_MASK) {
case MPC52xx_PSC_MODE_5_BITS:
*bits = 5;
break;
case MPC52xx_PSC_MODE_6_BITS:
*bits = 6;
break;
case MPC52xx_PSC_MODE_7_BITS:
*bits = 7;
break;
case MPC52xx_PSC_MODE_8_BITS:
default:
*bits = 8;
}
if (mr1 & MPC52xx_PSC_MODE_PARNONE)
*parity = 'n';
else
*parity = mr1 & MPC52xx_PSC_MODE_PARODD ? 'o' : 'e';
}
static void
mpc52xx_console_write(struct console *co, const char *s, unsigned int count)
{
struct uart_port *port = &mpc52xx_uart_ports[co->index];
unsigned int i, j;
/* Disable interrupts */
psc_ops->cw_disable_ints(port);
/* Wait the TX buffer to be empty */
j = 5000000; /* Maximum wait */
while (!mpc52xx_uart_tx_empty(port) && --j)
udelay(1);
/* Write all the chars */
for (i = 0; i < count; i++, s++) {
/* Line return handling */
if (*s == '\n')
psc_ops->write_char(port, '\r');
/* Send the char */
psc_ops->write_char(port, *s);
/* Wait the TX buffer to be empty */
j = 20000; /* Maximum wait */
while (!mpc52xx_uart_tx_empty(port) && --j)
udelay(1);
}
/* Restore interrupt state */
psc_ops->cw_restore_ints(port);
}
static int __init
mpc52xx_console_setup(struct console *co, char *options)
{
struct uart_port *port = &mpc52xx_uart_ports[co->index];
struct device_node *np = mpc52xx_uart_nodes[co->index];
unsigned int uartclk;
struct resource res;
int ret;
int baud = CONFIG_SERIAL_MPC52xx_CONSOLE_BAUD;
int bits = 8;
int parity = 'n';
int flow = 'n';
pr_debug("mpc52xx_console_setup co=%p, co->index=%i, options=%s\n",
co, co->index, options);
if ((co->index < 0) || (co->index >= MPC52xx_PSC_MAXNUM)) {
pr_debug("PSC%x out of range\n", co->index);
return -EINVAL;
}
if (!np) {
pr_debug("PSC%x not found in device tree\n", co->index);
return -EINVAL;
}