linux/drivers/tty/serial/mpc52xx_uart.c
Frank Benkert e0955acecf mpc5200b/uart: select more tolerant uart prescaler on low baudrates
In addition to the /32 prescaler, the MPC5200B supports a second
baudrate prescaler /4 to reach higher baudrates.

The current calculation (introduced with commit 0d1f22e4) in the kernel
preferes this low prescaler as often as possible, but with some
imprecise counterparts the communication on low baudrates fails.

According a support-mail from freescale the low prescaler (/4) allows
just 1% tolerance in bittiming in contrast to 4% of the high prescaler
(/32).  The prescaler not only affects the baudrate-calculation, but
also the sampling of the bits on the wire.

With this patch, we use the slightly less precise, but higher tolerant
prescaler calculation on low baudrates up to (and including) 115200 baud
and the more precise calculation above.

Tested on a custom MPC5200B board with "fsl,mpc5200b-psc-uart".

Calculation Examples with prescaler (PS) 4 and 32 and divisor (DIV) on
various baudrates. Real stands for the real baudrate generated and Diff
for the differences between:
     50 Baud PS 32 DIV 0xa122 Real      50 Diff   0.00%
     75 Baud PS 32 DIV 0x6b6c Real      75 Diff   0.00%
    110 Baud PS 32 DIV 0x493e Real     110 Diff   0.00%
    134 Baud PS 32 DIV 0x3c20 Real     133 Diff   0.75%
    150 Baud PS 32 DIV 0x35b6 Real     150 Diff   0.00%
    200 Baud PS 32 DIV 0x2849 Real     199 Diff   0.50%
    300 Baud PS  4 DIV 0xd6d8 Real     300 Diff   0.00%
             PS 32 DIV 0x1adb Real     300 Diff   0.00%
    600 Baud PS  4 DIV 0x6b6c Real     600 Diff   0.00%
             PS 32 DIV 0x0d6e Real     599 Diff   0.17%
   1200 Baud PS  4 DIV 0x35b6 Real    1200 Diff   0.00%
             PS 32 DIV 0x06b7 Real    1199 Diff   0.08%
   1800 Baud PS  4 DIV 0x23cf Real    1799 Diff   0.06%
             PS 32 DIV 0x047a Real    1799 Diff   0.06%
   2400 Baud PS  4 DIV 0x1adb Real    2400 Diff   0.00%
             PS 32 DIV 0x035b Real    2401 Diff - 0.04%
   4800 Baud PS  4 DIV 0x0d6e Real    4799 Diff   0.02%
             PS 32 DIV 0x01ae Real    4796 Diff   0.08%
   9600 Baud PS  4 DIV 0x06b7 Real    9598 Diff   0.02%
             PS 32 DIV 0x00d7 Real    9593 Diff   0.07%
  19200 Baud PS  4 DIV 0x035b Real   19208 Diff - 0.04%
             PS 32 DIV 0x006b Real   19275 Diff - 0.39%
  38400 Baud PS  4 DIV 0x01ae Real   38372 Diff   0.07%
             PS 32 DIV 0x0036 Real   38194 Diff   0.54%
  57600 Baud PS  4 DIV 0x011e Real   57692 Diff - 0.16%
             PS 32 DIV 0x0024 Real   57291 Diff   0.54%
  76800 Baud PS  4 DIV 0x00d7 Real   76744 Diff   0.07%
             PS 32 DIV 0x001b Real   76388 Diff   0.54%
 115200 Baud PS  4 DIV 0x008f Real  115384 Diff - 0.16%
             PS 32 DIV 0x0012 Real  114583 Diff   0.54%
 153600 Baud PS  4 DIV 0x006b Real  154205 Diff - 0.39%
             PS 32 DIV 0x000d Real  158653 Diff - 3.29%
 230400 Baud PS  4 DIV 0x0048 Real  229166 Diff   0.54%
             PS 32 DIV 0x0009 Real  229166 Diff   0.54%
 307200 Baud PS  4 DIV 0x0036 Real  305555 Diff   0.54%
             PS 32 DIV 0x0007 Real  294642 Diff   4.09%
 460800 Baud PS  4 DIV 0x0024 Real  458333 Diff   0.54%
             PS 32 DIV 0x0005 Real  412500 Diff  10.48%
 500000 Baud PS  4 DIV 0x0021 Real  500000 Diff   0.00%
             PS 32 DIV 0x0004 Real  515625 Diff - 3.13%
 576000 Baud PS  4 DIV 0x001d Real  568965 Diff   1.22%
             PS 32 DIV 0x0004 Real  515625 Diff  10.48%
 614400 Baud PS  4 DIV 0x001b Real  611111 Diff   0.54%
             PS 32 DIV 0x0003 Real  687500 Diff -11.90%
 921600 Baud PS  4 DIV 0x0012 Real  916666 Diff   0.54%
             PS 32 DIV 0x0002 Real 1031250 Diff -11.90%
1000000 Baud PS  4 DIV 0x0011 Real  970588 Diff   2.94%
             PS 32 DIV 0x0002 Real 1031250 Diff - 3.13%
1152000 Baud PS  4 DIV 0x000e Real 1178571 Diff - 2.31%
             PS 32 DIV 0x0002 Real 1031250 Diff  10.48%
1500000 Baud PS  4 DIV 0x000b Real 1500000 Diff   0.00%
             PS 32 DIV 0x0001 Real 2062500 Diff -37.50%
2000000 Baud PS  4 DIV 0x0008 Real 2062500 Diff - 3.13%
             PS 32 DIV 0x0001 Real 2062500 Diff - 3.13%
2500000 Baud PS  4 DIV 0x0007 Real 2357142 Diff   5.71%
             PS 32 DIV 0x0001 Real 2062500 Diff  17.50%
3000000 Baud PS  4 DIV 0x0006 Real 2750000 Diff   8.33%
             PS 32 DIV 0x0001 Real 2062500 Diff  31.25%
3500000 Baud PS  4 DIV 0x0005 Real 3300000 Diff   5.71%
             PS 32 DIV 0x0001 Real 2062500 Diff  41.07%
4000000 Baud PS  4 DIV 0x0004 Real 4125000 Diff - 3.13%
             PS 32 DIV 0x0001 Real 2062500 Diff  48.44%

Signed-off-by: Frank Benkert <frank.benkert@avat.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-03-08 13:15:50 -08:00

1527 lines
39 KiB
C

/*
* 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 <tnt@246tNt.com>
*
* Some of the code has been inspired/copied from the 2.4 code written
* by Dale Farnsworth <dfarnsworth@mvista.com>.
*
* Copyright (C) 2008 Freescale Semiconductor Inc.
* John Rigby <jrigby@gmail.com>
* Added support for MPC5121
* Copyright (C) 2006 Secret Lab Technologies Ltd.
* Grant Likely <grant.likely@secretlab.ca>
* Copyright (C) 2004-2006 Sylvain Munaut <tnt@246tNt.com>
* 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.
*/
#undef DEBUG
#include <linux/device.h>
#include <linux/module.h>
#include <linux/tty.h>
#include <linux/tty_flip.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 <linux/clk.h>
#include <asm/mpc52xx.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);
static irqreturn_t mpc5xxx_uart_process_int(struct uart_port *port);
/* 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 int (*set_baudrate)(struct uart_port *port,
struct ktermios *new,
struct ktermios *old);
int (*clock)(struct uart_port *port, int enable);
int (*fifoc_init)(void);
void (*fifoc_uninit)(void);
void (*get_irq)(struct uart_port *, struct device_node *);
irqreturn_t (*handle_irq)(struct uart_port *port);
};
/* setting the prescaler and divisor reg is common for all chips */
static inline void mpc52xx_set_divisor(struct mpc52xx_psc __iomem *psc,
u16 prescaler, unsigned int divisor)
{
/* select prescaler */
out_be16(&psc->mpc52xx_psc_clock_select, prescaler);
out_8(&psc->ctur, divisor >> 8);
out_8(&psc->ctlr, divisor & 0xff);
}
#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);
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);
}
static unsigned int mpc5200_psc_set_baudrate(struct uart_port *port,
struct ktermios *new,
struct ktermios *old)
{
unsigned int baud;
unsigned int divisor;
/* The 5200 has a fixed /32 prescaler, uartclk contains the ipb freq */
baud = uart_get_baud_rate(port, new, old,
port->uartclk / (32 * 0xffff) + 1,
port->uartclk / 32);
divisor = (port->uartclk + 16 * baud) / (32 * baud);
/* enable the /32 prescaler and set the divisor */
mpc52xx_set_divisor(PSC(port), 0xdd00, divisor);
return baud;
}
static unsigned int mpc5200b_psc_set_baudrate(struct uart_port *port,
struct ktermios *new,
struct ktermios *old)
{
unsigned int baud;
unsigned int divisor;
u16 prescaler;
/* The 5200B has a selectable /4 or /32 prescaler, uartclk contains the
* ipb freq */
baud = uart_get_baud_rate(port, new, old,
port->uartclk / (32 * 0xffff) + 1,
port->uartclk / 4);
divisor = (port->uartclk + 2 * baud) / (4 * baud);
/* select the proper prescaler and set the divisor
* prefer high prescaler for more tolerance on low baudrates */
if (divisor > 0xffff || baud <= 115200) {
divisor = (divisor + 4) / 8;
prescaler = 0xdd00; /* /32 */
} else
prescaler = 0xff00; /* /4 */
mpc52xx_set_divisor(PSC(port), prescaler, divisor);
return baud;
}
static void mpc52xx_psc_get_irq(struct uart_port *port, struct device_node *np)
{
port->irqflags = 0;
port->irq = irq_of_parse_and_map(np, 0);
}
/* 52xx specific interrupt handler. The caller holds the port lock */
static irqreturn_t mpc52xx_psc_handle_irq(struct uart_port *port)
{
return mpc5xxx_uart_process_int(port);
}
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,
.set_baudrate = mpc5200_psc_set_baudrate,
.get_irq = mpc52xx_psc_get_irq,
.handle_irq = mpc52xx_psc_handle_irq,
};
static struct psc_ops mpc5200b_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,
.set_baudrate = mpc5200b_psc_set_baudrate,
.get_irq = mpc52xx_psc_get_irq,
.handle_irq = mpc52xx_psc_handle_irq,
};
#endif /* CONFIG_MPC52xx */
#ifdef CONFIG_PPC_MPC512x
#define FIFO_512x(port) ((struct mpc512x_psc_fifo __iomem *)(PSC(port)+1))
/* PSC FIFO Controller for mpc512x */
struct psc_fifoc {
u32 fifoc_cmd;
u32 fifoc_int;
u32 fifoc_dma;
u32 fifoc_axe;
u32 fifoc_debug;
};
static struct psc_fifoc __iomem *psc_fifoc;
static unsigned int psc_fifoc_irq;
static void mpc512x_psc_fifo_init(struct uart_port *port)
{
/* /32 prescaler */
out_be16(&PSC(port)->mpc52xx_psc_clock_select, 0xdd00);
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 int mpc512x_psc_set_baudrate(struct uart_port *port,
struct ktermios *new,
struct ktermios *old)
{
unsigned int baud;
unsigned int divisor;
/*
* The "MPC5121e Microcontroller Reference Manual, Rev. 3" says on
* pg. 30-10 that the chip supports a /32 and a /10 prescaler.
* Furthermore, it states that "After reset, the prescaler by 10
* for the UART mode is selected", but the reset register value is
* 0x0000 which means a /32 prescaler. This is wrong.
*
* In reality using /32 prescaler doesn't work, as it is not supported!
* Use /16 or /10 prescaler, see "MPC5121e Hardware Design Guide",
* Chapter 4.1 PSC in UART Mode.
* Calculate with a /16 prescaler here.
*/
/* uartclk contains the ips freq */
baud = uart_get_baud_rate(port, new, old,
port->uartclk / (16 * 0xffff) + 1,
port->uartclk / 16);
divisor = (port->uartclk + 8 * baud) / (16 * baud);
/* enable the /16 prescaler and set the divisor */
mpc52xx_set_divisor(PSC(port), 0xdd00, divisor);
return baud;
}
/* Init PSC FIFO Controller */
static int __init mpc512x_psc_fifoc_init(void)
{
struct device_node *np;
np = of_find_compatible_node(NULL, NULL,
"fsl,mpc5121-psc-fifo");
if (!np) {
pr_err("%s: Can't find FIFOC node\n", __func__);
return -ENODEV;
}
psc_fifoc = of_iomap(np, 0);
if (!psc_fifoc) {
pr_err("%s: Can't map FIFOC\n", __func__);
of_node_put(np);
return -ENODEV;
}
psc_fifoc_irq = irq_of_parse_and_map(np, 0);
of_node_put(np);
if (psc_fifoc_irq == 0) {
pr_err("%s: Can't get FIFOC irq\n", __func__);
iounmap(psc_fifoc);
return -ENODEV;
}
return 0;
}
static void __exit mpc512x_psc_fifoc_uninit(void)
{
iounmap(psc_fifoc);
}
/* 512x specific interrupt handler. The caller holds the port lock */
static irqreturn_t mpc512x_psc_handle_irq(struct uart_port *port)
{
unsigned long fifoc_int;
int psc_num;
/* Read pending PSC FIFOC interrupts */
fifoc_int = in_be32(&psc_fifoc->fifoc_int);
/* Check if it is an interrupt for this port */
psc_num = (port->mapbase & 0xf00) >> 8;
if (test_bit(psc_num, &fifoc_int) ||
test_bit(psc_num + 16, &fifoc_int))
return mpc5xxx_uart_process_int(port);
return IRQ_NONE;
}
static int mpc512x_psc_clock(struct uart_port *port, int enable)
{
struct clk *psc_clk;
int psc_num;
char clk_name[10];
if (uart_console(port))
return 0;
psc_num = (port->mapbase & 0xf00) >> 8;
snprintf(clk_name, sizeof(clk_name), "psc%d_clk", psc_num);
psc_clk = clk_get(port->dev, clk_name);
if (IS_ERR(psc_clk)) {
dev_err(port->dev, "Failed to get PSC clock entry!\n");
return -ENODEV;
}
dev_dbg(port->dev, "%s %sable\n", clk_name, enable ? "en" : "dis");
if (enable)
clk_enable(psc_clk);
else
clk_disable(psc_clk);
return 0;
}
static void mpc512x_psc_get_irq(struct uart_port *port, struct device_node *np)
{
port->irqflags = IRQF_SHARED;
port->irq = psc_fifoc_irq;
}
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,
.set_baudrate = mpc512x_psc_set_baudrate,
.clock = mpc512x_psc_clock,
.fifoc_init = mpc512x_psc_fifoc_init,
.fifoc_uninit = mpc512x_psc_fifoc_uninit,
.get_irq = mpc512x_psc_get_irq,
.handle_irq = mpc512x_psc_handle_irq,
};
#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;
if (psc_ops->clock) {
ret = psc_ops->clock(port, 1);
if (ret)
return ret;
}
/* Request IRQ */
ret = request_irq(port->irq, mpc52xx_uart_int,
port->irqflags, "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);
if (psc_ops->clock)
psc_ops->clock(port, 0);
/* 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 int j;
unsigned int baud;
/* 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;
}
/* Get the lock */
spin_lock_irqsave(&port->lock, flags);
/* 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);
baud = psc_ops->set_baudrate(port, new, old);
/* Update the per-port timeout */
uart_update_timeout(port, new->c_cflag, baud);
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)
{
/*
* We keep using PORT_MPC52xx for historic reasons although it applies
* for MPC512x, too, but print "MPC5xxx" to not irritate users
*/
return port->type == PORT_MPC52xx ? "MPC5xxx 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 != UPIO_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->state->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->state->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
mpc5xxx_uart_process_int(struct uart_port *port)
{
unsigned long pass = ISR_PASS_LIMIT;
unsigned int keepgoing;
u8 status;
/* 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);
return IRQ_HANDLED;
}
static irqreturn_t
mpc52xx_uart_int(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
irqreturn_t ret;
spin_lock(&port->lock);
ret = psc_ops->handle_irq(port);
spin_unlock(&port->lock);
return ret;
}
/* ======================================================================== */
/* 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;
}
pr_debug("Console on ttyPSC%x is %s\n",
co->index, mpc52xx_uart_nodes[co->index]->full_name);
/* Fetch register locations */
ret = of_address_to_resource(np, 0, &res);
if (ret) {
pr_debug("Could not get resources for PSC%x\n", co->index);
return ret;
}
uartclk = mpc5xxx_get_bus_frequency(np);
if (uartclk == 0) {
pr_debug("Could not find uart clock frequency!\n");
return -EINVAL;
}
/* Basic port init. Needed since we use some uart_??? func before
* real init for early access */
spin_lock_init(&port->lock);
port->uartclk = uartclk;
port->ops = &mpc52xx_uart_ops;
port->mapbase = res.start;
port->membase = ioremap(res.start, sizeof(struct mpc52xx_psc));
port->irq = irq_of_parse_and_map(np, 0);
if (port->membase == NULL)
return -EINVAL;
pr_debug("mpc52xx-psc uart at %p, mapped to %p, irq=%x, freq=%i\n",
(void *)port->mapbase, port->membase,
port->irq, port->uartclk);
/* Setup the port parameters accoding to options */
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
else
mpc52xx_console_get_options(port, &baud, &parity, &bits, &flow);
pr_debug("Setting console parameters: %i %i%c1 flow=%c\n",
baud, bits, parity, flow);
return uart_set_options(port, co, baud, parity, bits, flow);
}
static struct uart_driver mpc52xx_uart_driver;
static struct console mpc52xx_console = {
.name = "ttyPSC",
.write = mpc52xx_console_write,
.device = uart_console_device,
.setup = mpc52xx_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1, /* Specified on the cmdline (e.g. console=ttyPSC0) */
.data = &mpc52xx_uart_driver,
};
static int __init
mpc52xx_console_init(void)
{
mpc52xx_uart_of_enumerate();
register_console(&mpc52xx_console);
return 0;
}
console_initcall(mpc52xx_console_init);
#define MPC52xx_PSC_CONSOLE &mpc52xx_console
#else
#define MPC52xx_PSC_CONSOLE NULL
#endif
/* ======================================================================== */
/* UART Driver */
/* ======================================================================== */
static struct uart_driver mpc52xx_uart_driver = {
.driver_name = "mpc52xx_psc_uart",
.dev_name = "ttyPSC",
.major = SERIAL_PSC_MAJOR,
.minor = SERIAL_PSC_MINOR,
.nr = MPC52xx_PSC_MAXNUM,
.cons = MPC52xx_PSC_CONSOLE,
};
/* ======================================================================== */
/* OF Platform Driver */
/* ======================================================================== */
static struct of_device_id mpc52xx_uart_of_match[] = {
#ifdef CONFIG_PPC_MPC52xx
{ .compatible = "fsl,mpc5200b-psc-uart", .data = &mpc5200b_psc_ops, },
{ .compatible = "fsl,mpc5200-psc-uart", .data = &mpc52xx_psc_ops, },
/* binding used by old lite5200 device trees: */
{ .compatible = "mpc5200-psc-uart", .data = &mpc52xx_psc_ops, },
/* binding used by efika: */
{ .compatible = "mpc5200-serial", .data = &mpc52xx_psc_ops, },
#endif
#ifdef CONFIG_PPC_MPC512x
{ .compatible = "fsl,mpc5121-psc-uart", .data = &mpc512x_psc_ops, },
#endif
{},
};
static int __devinit mpc52xx_uart_of_probe(struct platform_device *op)
{
int idx = -1;
unsigned int uartclk;
struct uart_port *port = NULL;
struct resource res;
int ret;
/* Check validity & presence */
for (idx = 0; idx < MPC52xx_PSC_MAXNUM; idx++)
if (mpc52xx_uart_nodes[idx] == op->dev.of_node)
break;
if (idx >= MPC52xx_PSC_MAXNUM)
return -EINVAL;
pr_debug("Found %s assigned to ttyPSC%x\n",
mpc52xx_uart_nodes[idx]->full_name, idx);
/* set the uart clock to the input clock of the psc, the different
* prescalers are taken into account in the set_baudrate() methods
* of the respective chip */
uartclk = mpc5xxx_get_bus_frequency(op->dev.of_node);
if (uartclk == 0) {
dev_dbg(&op->dev, "Could not find uart clock frequency!\n");
return -EINVAL;
}
/* Init the port structure */
port = &mpc52xx_uart_ports[idx];
spin_lock_init(&port->lock);
port->uartclk = uartclk;
port->fifosize = 512;
port->iotype = UPIO_MEM;
port->flags = UPF_BOOT_AUTOCONF |
(uart_console(port) ? 0 : UPF_IOREMAP);
port->line = idx;
port->ops = &mpc52xx_uart_ops;
port->dev = &op->dev;
/* Search for IRQ and mapbase */
ret = of_address_to_resource(op->dev.of_node, 0, &res);
if (ret)
return ret;
port->mapbase = res.start;
if (!port->mapbase) {
dev_dbg(&op->dev, "Could not allocate resources for PSC\n");
return -EINVAL;
}
psc_ops->get_irq(port, op->dev.of_node);
if (port->irq == 0) {
dev_dbg(&op->dev, "Could not get irq\n");
return -EINVAL;
}
dev_dbg(&op->dev, "mpc52xx-psc uart at %p, irq=%x, freq=%i\n",
(void *)port->mapbase, port->irq, port->uartclk);
/* Add the port to the uart sub-system */
ret = uart_add_one_port(&mpc52xx_uart_driver, port);
if (ret)
return ret;
dev_set_drvdata(&op->dev, (void *)port);
return 0;
}
static int
mpc52xx_uart_of_remove(struct platform_device *op)
{
struct uart_port *port = dev_get_drvdata(&op->dev);
dev_set_drvdata(&op->dev, NULL);
if (port)
uart_remove_one_port(&mpc52xx_uart_driver, port);
return 0;
}
#ifdef CONFIG_PM
static int
mpc52xx_uart_of_suspend(struct platform_device *op, pm_message_t state)
{
struct uart_port *port = (struct uart_port *) dev_get_drvdata(&op->dev);
if (port)
uart_suspend_port(&mpc52xx_uart_driver, port);
return 0;
}
static int
mpc52xx_uart_of_resume(struct platform_device *op)
{
struct uart_port *port = (struct uart_port *) dev_get_drvdata(&op->dev);
if (port)
uart_resume_port(&mpc52xx_uart_driver, port);
return 0;
}
#endif
static void
mpc52xx_uart_of_assign(struct device_node *np)
{
int i;
/* Find the first free PSC number */
for (i = 0; i < MPC52xx_PSC_MAXNUM; i++) {
if (mpc52xx_uart_nodes[i] == NULL) {
of_node_get(np);
mpc52xx_uart_nodes[i] = np;
return;
}
}
}
static void
mpc52xx_uart_of_enumerate(void)
{
static int enum_done;
struct device_node *np;
const struct of_device_id *match;
int i;
if (enum_done)
return;
/* Assign index to each PSC in device tree */
for_each_matching_node(np, mpc52xx_uart_of_match) {
match = of_match_node(mpc52xx_uart_of_match, np);
psc_ops = match->data;
mpc52xx_uart_of_assign(np);
}
enum_done = 1;
for (i = 0; i < MPC52xx_PSC_MAXNUM; i++) {
if (mpc52xx_uart_nodes[i])
pr_debug("%s assigned to ttyPSC%x\n",
mpc52xx_uart_nodes[i]->full_name, i);
}
}
MODULE_DEVICE_TABLE(of, mpc52xx_uart_of_match);
static struct platform_driver mpc52xx_uart_of_driver = {
.probe = mpc52xx_uart_of_probe,
.remove = mpc52xx_uart_of_remove,
#ifdef CONFIG_PM
.suspend = mpc52xx_uart_of_suspend,
.resume = mpc52xx_uart_of_resume,
#endif
.driver = {
.name = "mpc52xx-psc-uart",
.owner = THIS_MODULE,
.of_match_table = mpc52xx_uart_of_match,
},
};
/* ======================================================================== */
/* Module */
/* ======================================================================== */
static int __init
mpc52xx_uart_init(void)
{
int ret;
printk(KERN_INFO "Serial: MPC52xx PSC UART driver\n");
ret = uart_register_driver(&mpc52xx_uart_driver);
if (ret) {
printk(KERN_ERR "%s: uart_register_driver failed (%i)\n",
__FILE__, ret);
return ret;
}
mpc52xx_uart_of_enumerate();
/*
* Map the PSC FIFO Controller and init if on MPC512x.
*/
if (psc_ops && psc_ops->fifoc_init) {
ret = psc_ops->fifoc_init();
if (ret)
return ret;
}
ret = platform_driver_register(&mpc52xx_uart_of_driver);
if (ret) {
printk(KERN_ERR "%s: platform_driver_register failed (%i)\n",
__FILE__, ret);
uart_unregister_driver(&mpc52xx_uart_driver);
return ret;
}
return 0;
}
static void __exit
mpc52xx_uart_exit(void)
{
if (psc_ops->fifoc_uninit)
psc_ops->fifoc_uninit();
platform_driver_unregister(&mpc52xx_uart_of_driver);
uart_unregister_driver(&mpc52xx_uart_driver);
}
module_init(mpc52xx_uart_init);
module_exit(mpc52xx_uart_exit);
MODULE_AUTHOR("Sylvain Munaut <tnt@246tNt.com>");
MODULE_DESCRIPTION("Freescale MPC52xx PSC UART");
MODULE_LICENSE("GPL");