linux/drivers/tty/serial/lpc32xx_hs.c

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/*
* High Speed Serial Ports on NXP LPC32xx SoC
*
* Authors: Kevin Wells <kevin.wells@nxp.com>
* Roland Stigge <stigge@antcom.de>
*
* Copyright (C) 2010 NXP Semiconductors
* Copyright (C) 2012 Roland Stigge
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/platform_device.h>
#include <linux/delay.h>
#include <linux/nmi.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/gpio.h>
#include <linux/of.h>
#include <mach/platform.h>
#include <mach/hardware.h>
/*
* High Speed UART register offsets
*/
#define LPC32XX_HSUART_FIFO(x) ((x) + 0x00)
#define LPC32XX_HSUART_LEVEL(x) ((x) + 0x04)
#define LPC32XX_HSUART_IIR(x) ((x) + 0x08)
#define LPC32XX_HSUART_CTRL(x) ((x) + 0x0C)
#define LPC32XX_HSUART_RATE(x) ((x) + 0x10)
#define LPC32XX_HSU_BREAK_DATA (1 << 10)
#define LPC32XX_HSU_ERROR_DATA (1 << 9)
#define LPC32XX_HSU_RX_EMPTY (1 << 8)
#define LPC32XX_HSU_TX_LEV(n) (((n) >> 8) & 0xFF)
#define LPC32XX_HSU_RX_LEV(n) ((n) & 0xFF)
#define LPC32XX_HSU_TX_INT_SET (1 << 6)
#define LPC32XX_HSU_RX_OE_INT (1 << 5)
#define LPC32XX_HSU_BRK_INT (1 << 4)
#define LPC32XX_HSU_FE_INT (1 << 3)
#define LPC32XX_HSU_RX_TIMEOUT_INT (1 << 2)
#define LPC32XX_HSU_RX_TRIG_INT (1 << 1)
#define LPC32XX_HSU_TX_INT (1 << 0)
#define LPC32XX_HSU_HRTS_INV (1 << 21)
#define LPC32XX_HSU_HRTS_TRIG_8B (0x0 << 19)
#define LPC32XX_HSU_HRTS_TRIG_16B (0x1 << 19)
#define LPC32XX_HSU_HRTS_TRIG_32B (0x2 << 19)
#define LPC32XX_HSU_HRTS_TRIG_48B (0x3 << 19)
#define LPC32XX_HSU_HRTS_EN (1 << 18)
#define LPC32XX_HSU_TMO_DISABLED (0x0 << 16)
#define LPC32XX_HSU_TMO_INACT_4B (0x1 << 16)
#define LPC32XX_HSU_TMO_INACT_8B (0x2 << 16)
#define LPC32XX_HSU_TMO_INACT_16B (0x3 << 16)
#define LPC32XX_HSU_HCTS_INV (1 << 15)
#define LPC32XX_HSU_HCTS_EN (1 << 14)
#define LPC32XX_HSU_OFFSET(n) ((n) << 9)
#define LPC32XX_HSU_BREAK (1 << 8)
#define LPC32XX_HSU_ERR_INT_EN (1 << 7)
#define LPC32XX_HSU_RX_INT_EN (1 << 6)
#define LPC32XX_HSU_TX_INT_EN (1 << 5)
#define LPC32XX_HSU_RX_TL1B (0x0 << 2)
#define LPC32XX_HSU_RX_TL4B (0x1 << 2)
#define LPC32XX_HSU_RX_TL8B (0x2 << 2)
#define LPC32XX_HSU_RX_TL16B (0x3 << 2)
#define LPC32XX_HSU_RX_TL32B (0x4 << 2)
#define LPC32XX_HSU_RX_TL48B (0x5 << 2)
#define LPC32XX_HSU_TX_TLEMPTY (0x0 << 0)
#define LPC32XX_HSU_TX_TL0B (0x0 << 0)
#define LPC32XX_HSU_TX_TL4B (0x1 << 0)
#define LPC32XX_HSU_TX_TL8B (0x2 << 0)
#define LPC32XX_HSU_TX_TL16B (0x3 << 0)
#define MODNAME "lpc32xx_hsuart"
struct lpc32xx_hsuart_port {
struct uart_port port;
};
#define FIFO_READ_LIMIT 128
#define MAX_PORTS 3
#define LPC32XX_TTY_NAME "ttyTX"
static struct lpc32xx_hsuart_port lpc32xx_hs_ports[MAX_PORTS];
#ifdef CONFIG_SERIAL_HS_LPC32XX_CONSOLE
static void wait_for_xmit_empty(struct uart_port *port)
{
unsigned int timeout = 10000;
do {
if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
port->membase))) == 0)
break;
if (--timeout == 0)
break;
udelay(1);
} while (1);
}
static void wait_for_xmit_ready(struct uart_port *port)
{
unsigned int timeout = 10000;
while (1) {
if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(
port->membase))) < 32)
break;
if (--timeout == 0)
break;
udelay(1);
}
}
static void lpc32xx_hsuart_console_putchar(struct uart_port *port, int ch)
{
wait_for_xmit_ready(port);
writel((u32)ch, LPC32XX_HSUART_FIFO(port->membase));
}
static void lpc32xx_hsuart_console_write(struct console *co, const char *s,
unsigned int count)
{
struct lpc32xx_hsuart_port *up = &lpc32xx_hs_ports[co->index];
unsigned long flags;
int locked = 1;
touch_nmi_watchdog();
local_irq_save(flags);
if (up->port.sysrq)
locked = 0;
else if (oops_in_progress)
locked = spin_trylock(&up->port.lock);
else
spin_lock(&up->port.lock);
uart_console_write(&up->port, s, count, lpc32xx_hsuart_console_putchar);
wait_for_xmit_empty(&up->port);
if (locked)
spin_unlock(&up->port.lock);
local_irq_restore(flags);
}
static int __init lpc32xx_hsuart_console_setup(struct console *co,
char *options)
{
struct uart_port *port;
int baud = 115200;
int bits = 8;
int parity = 'n';
int flow = 'n';
if (co->index >= MAX_PORTS)
co->index = 0;
port = &lpc32xx_hs_ports[co->index].port;
if (!port->membase)
return -ENODEV;
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
return uart_set_options(port, co, baud, parity, bits, flow);
}
static struct uart_driver lpc32xx_hsuart_reg;
static struct console lpc32xx_hsuart_console = {
.name = LPC32XX_TTY_NAME,
.write = lpc32xx_hsuart_console_write,
.device = uart_console_device,
.setup = lpc32xx_hsuart_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &lpc32xx_hsuart_reg,
};
static int __init lpc32xx_hsuart_console_init(void)
{
register_console(&lpc32xx_hsuart_console);
return 0;
}
console_initcall(lpc32xx_hsuart_console_init);
#define LPC32XX_HSUART_CONSOLE (&lpc32xx_hsuart_console)
#else
#define LPC32XX_HSUART_CONSOLE NULL
#endif
static struct uart_driver lpc32xx_hs_reg = {
.owner = THIS_MODULE,
.driver_name = MODNAME,
.dev_name = LPC32XX_TTY_NAME,
.nr = MAX_PORTS,
.cons = LPC32XX_HSUART_CONSOLE,
};
static int uarts_registered;
static unsigned int __serial_get_clock_div(unsigned long uartclk,
unsigned long rate)
{
u32 div, goodrate, hsu_rate, l_hsu_rate, comprate;
u32 rate_diff;
/* Find the closest divider to get the desired clock rate */
div = uartclk / rate;
goodrate = hsu_rate = (div / 14) - 1;
if (hsu_rate != 0)
hsu_rate--;
/* Tweak divider */
l_hsu_rate = hsu_rate + 3;
rate_diff = 0xFFFFFFFF;
while (hsu_rate < l_hsu_rate) {
comprate = uartclk / ((hsu_rate + 1) * 14);
if (abs(comprate - rate) < rate_diff) {
goodrate = hsu_rate;
rate_diff = abs(comprate - rate);
}
hsu_rate++;
}
if (hsu_rate > 0xFF)
hsu_rate = 0xFF;
return goodrate;
}
static void __serial_uart_flush(struct uart_port *port)
{
u32 tmp;
int cnt = 0;
while ((readl(LPC32XX_HSUART_LEVEL(port->membase)) > 0) &&
(cnt++ < FIFO_READ_LIMIT))
tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
}
static void __serial_lpc32xx_rx(struct uart_port *port)
{
struct tty_port *tport = &port->state->port;
unsigned int tmp, flag;
/* Read data from FIFO and push into terminal */
tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
while (!(tmp & LPC32XX_HSU_RX_EMPTY)) {
flag = TTY_NORMAL;
port->icount.rx++;
if (tmp & LPC32XX_HSU_ERROR_DATA) {
/* Framing error */
writel(LPC32XX_HSU_FE_INT,
LPC32XX_HSUART_IIR(port->membase));
port->icount.frame++;
flag = TTY_FRAME;
tty_insert_flip_char(tport, 0, TTY_FRAME);
}
tty_insert_flip_char(tport, (tmp & 0xFF), flag);
tmp = readl(LPC32XX_HSUART_FIFO(port->membase));
}
tty: serial: lpc32xx_hs: drop uart_port->lock before calling tty_flip_buffer_push() The current driver triggers a lockdep warning for if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels and comes up only on SMP kernels. Crash looks like this (produced with samsung.c driver): ----- [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) from [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0) [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0x38) from [<c020a1a8>] (s3c24xx_serial_rx_chars+0) [<c020a1a8>] (s3c24xx_serial_rx_chars+0x12c/0x260) from [<c020aae8>] (s3c64xx_serial_handle_irq+) [<c020aae8>] (s3c64xx_serial_handle_irq+0x48/0x60) from [<c006aaa0>] (handle_irq_event_percpu+0x) [<c006aaa0>] (handle_irq_event_percpu+0x50/0x194) from [<c006ac20>] (handle_irq_event+0x3c/0x5c) [<c006ac20>] (handle_irq_event+0x3c/0x5c) from [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) from [<c006a4a4>] (generic_handle_irq+0x20/0x30) [<c006a4a4>] (generic_handle_irq+0x20/0x30) from [<c000f454>] (handle_IRQ+0x38/0x94) [<c000f454>] (handle_IRQ+0x38/0x94) from [<c0008538>] (gic_handle_irq+0x34/0x68) [<c0008538>] (gic_handle_irq+0x34/0x68) from [<c00123c0>] (__irq_svc+0x40/0x70) Exception stack(0xc04cdf70 to 0xc04cdfb8) df60: 00000000 00000000 0000166e 00000000 df80: c04cc000 c050278f c050278f 00000001 c04d444c 410fc0f4 c03649b0 00000000 dfa0: 00000001 c04cdfb8 c000f758 c000f75c 60070013 ffffffff [<c00123c0>] (__irq_svc+0x40/0x70) from [<c000f75c>] (arch_cpu_idle+0x28/0x30) [<c000f75c>] (arch_cpu_idle+0x28/0x30) from [<c0054888>] (cpu_startup_entry+0x5c/0x148) [<c0054888>] (cpu_startup_entry+0x5c/0x148) from [<c0497aa4>] (start_kernel+0x334/0x38c) BUG: spinlock lockup suspected on CPU#0, kworker/0:1/360 lock: s3c24xx_serial_ports+0x1d8/0x370, .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1 CPU: 0 PID: 360 Comm: kworker/0:1 Not tainted 3.11.0-rc6-next-20130819-00003-g75485f1 #2 Workqueue: events flush_to_ldisc [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) from [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) from [<c0203224>] (uart_start+0x18/0x34) [<c0203224>] (uart_start+0x18/0x34) from [<c01ef890>] (__receive_buf+0x4b4/0x738) [<c01ef890>] (__receive_buf+0x4b4/0x738) from [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) from [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) from [<c0031af0>] (process_one_work+0xfc/0x348) [<c0031af0>] (process_one_work+0xfc/0x348) from [<c0032138>] (worker_thread+0x138/0x37c) [<c0032138>] (worker_thread+0x138/0x37c) from [<c0037a7c>] (kthread+0xa4/0xb0) [<c0037a7c>] (kthread+0xa4/0xb0) from [<c000e5f8>] (ret_from_fork+0x14/0x3c) ----- Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call. Similar stuff was already done for few other drivers in the past, like: commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner <tglx@linutronix.de> Date: Tue May 29 21:53:50 2007 +0100 [ARM] 4417/1: Serial: Fix AMBA drivers locking Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-19 22:44:15 +08:00
spin_unlock(&port->lock);
tty_flip_buffer_push(tport);
tty: serial: lpc32xx_hs: drop uart_port->lock before calling tty_flip_buffer_push() The current driver triggers a lockdep warning for if tty_flip_buffer_push() is called with uart_port->lock locked. This never shows up on UP kernels and comes up only on SMP kernels. Crash looks like this (produced with samsung.c driver): ----- [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) [<c01b59ac>] (do_raw_spin_unlock+0xc4/0xd8) from [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0) [<c03627e4>] (_raw_spin_unlock_irqrestore+0xc/0x38) from [<c020a1a8>] (s3c24xx_serial_rx_chars+0) [<c020a1a8>] (s3c24xx_serial_rx_chars+0x12c/0x260) from [<c020aae8>] (s3c64xx_serial_handle_irq+) [<c020aae8>] (s3c64xx_serial_handle_irq+0x48/0x60) from [<c006aaa0>] (handle_irq_event_percpu+0x) [<c006aaa0>] (handle_irq_event_percpu+0x50/0x194) from [<c006ac20>] (handle_irq_event+0x3c/0x5c) [<c006ac20>] (handle_irq_event+0x3c/0x5c) from [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) [<c006d864>] (handle_fasteoi_irq+0x80/0x13c) from [<c006a4a4>] (generic_handle_irq+0x20/0x30) [<c006a4a4>] (generic_handle_irq+0x20/0x30) from [<c000f454>] (handle_IRQ+0x38/0x94) [<c000f454>] (handle_IRQ+0x38/0x94) from [<c0008538>] (gic_handle_irq+0x34/0x68) [<c0008538>] (gic_handle_irq+0x34/0x68) from [<c00123c0>] (__irq_svc+0x40/0x70) Exception stack(0xc04cdf70 to 0xc04cdfb8) df60: 00000000 00000000 0000166e 00000000 df80: c04cc000 c050278f c050278f 00000001 c04d444c 410fc0f4 c03649b0 00000000 dfa0: 00000001 c04cdfb8 c000f758 c000f75c 60070013 ffffffff [<c00123c0>] (__irq_svc+0x40/0x70) from [<c000f75c>] (arch_cpu_idle+0x28/0x30) [<c000f75c>] (arch_cpu_idle+0x28/0x30) from [<c0054888>] (cpu_startup_entry+0x5c/0x148) [<c0054888>] (cpu_startup_entry+0x5c/0x148) from [<c0497aa4>] (start_kernel+0x334/0x38c) BUG: spinlock lockup suspected on CPU#0, kworker/0:1/360 lock: s3c24xx_serial_ports+0x1d8/0x370, .magic: dead4ead, .owner: <none>/-1, .owner_cpu: -1 CPU: 0 PID: 360 Comm: kworker/0:1 Not tainted 3.11.0-rc6-next-20130819-00003-g75485f1 #2 Workqueue: events flush_to_ldisc [<c0014d58>] (unwind_backtrace+0x0/0xf8) from [<c0011908>] (show_stack+0x10/0x14) [<c0011908>] (show_stack+0x10/0x14) from [<c035da34>] (dump_stack+0x6c/0xac) [<c035da34>] (dump_stack+0x6c/0xac) from [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) [<c01b581c>] (do_raw_spin_lock+0x100/0x17c) from [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) [<c03628a0>] (_raw_spin_lock_irqsave+0x20/0x28) from [<c0203224>] (uart_start+0x18/0x34) [<c0203224>] (uart_start+0x18/0x34) from [<c01ef890>] (__receive_buf+0x4b4/0x738) [<c01ef890>] (__receive_buf+0x4b4/0x738) from [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) [<c01efb44>] (n_tty_receive_buf2+0x30/0x98) from [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) [<c01f2ba8>] (flush_to_ldisc+0xec/0x138) from [<c0031af0>] (process_one_work+0xfc/0x348) [<c0031af0>] (process_one_work+0xfc/0x348) from [<c0032138>] (worker_thread+0x138/0x37c) [<c0032138>] (worker_thread+0x138/0x37c) from [<c0037a7c>] (kthread+0xa4/0xb0) [<c0037a7c>] (kthread+0xa4/0xb0) from [<c000e5f8>] (ret_from_fork+0x14/0x3c) ----- Release the port lock before calling tty_flip_buffer_push() and reacquire it after the call. Similar stuff was already done for few other drivers in the past, like: commit 2389b272168ceec056ca1d8a870a97fa9c26e11a Author: Thomas Gleixner <tglx@linutronix.de> Date: Tue May 29 21:53:50 2007 +0100 [ARM] 4417/1: Serial: Fix AMBA drivers locking Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-08-19 22:44:15 +08:00
spin_lock(&port->lock);
}
static void __serial_lpc32xx_tx(struct uart_port *port)
{
struct circ_buf *xmit = &port->state->xmit;
unsigned int tmp;
if (port->x_char) {
writel((u32)port->x_char, LPC32XX_HSUART_FIFO(port->membase));
port->icount.tx++;
port->x_char = 0;
return;
}
if (uart_circ_empty(xmit) || uart_tx_stopped(port))
goto exit_tx;
/* Transfer data */
while (LPC32XX_HSU_TX_LEV(readl(
LPC32XX_HSUART_LEVEL(port->membase))) < 64) {
writel((u32) xmit->buf[xmit->tail],
LPC32XX_HSUART_FIFO(port->membase));
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
port->icount.tx++;
if (uart_circ_empty(xmit))
break;
}
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(port);
exit_tx:
if (uart_circ_empty(xmit)) {
tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
tmp &= ~LPC32XX_HSU_TX_INT_EN;
writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
}
}
static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id)
{
struct uart_port *port = dev_id;
struct tty_port *tport = &port->state->port;
u32 status;
spin_lock(&port->lock);
/* Read UART status and clear latched interrupts */
status = readl(LPC32XX_HSUART_IIR(port->membase));
if (status & LPC32XX_HSU_BRK_INT) {
/* Break received */
writel(LPC32XX_HSU_BRK_INT, LPC32XX_HSUART_IIR(port->membase));
port->icount.brk++;
uart_handle_break(port);
}
/* Framing error */
if (status & LPC32XX_HSU_FE_INT)
writel(LPC32XX_HSU_FE_INT, LPC32XX_HSUART_IIR(port->membase));
if (status & LPC32XX_HSU_RX_OE_INT) {
/* Receive FIFO overrun */
writel(LPC32XX_HSU_RX_OE_INT,
LPC32XX_HSUART_IIR(port->membase));
port->icount.overrun++;
tty_insert_flip_char(tport, 0, TTY_OVERRUN);
tty_schedule_flip(tport);
}
/* Data received? */
if (status & (LPC32XX_HSU_RX_TIMEOUT_INT | LPC32XX_HSU_RX_TRIG_INT))
__serial_lpc32xx_rx(port);
/* Transmit data request? */
if ((status & LPC32XX_HSU_TX_INT) && (!uart_tx_stopped(port))) {
writel(LPC32XX_HSU_TX_INT, LPC32XX_HSUART_IIR(port->membase));
__serial_lpc32xx_tx(port);
}
spin_unlock(&port->lock);
return IRQ_HANDLED;
}
/* port->lock is not held. */
static unsigned int serial_lpc32xx_tx_empty(struct uart_port *port)
{
unsigned int ret = 0;
if (LPC32XX_HSU_TX_LEV(readl(LPC32XX_HSUART_LEVEL(port->membase))) == 0)
ret = TIOCSER_TEMT;
return ret;
}
/* port->lock held by caller. */
static void serial_lpc32xx_set_mctrl(struct uart_port *port,
unsigned int mctrl)
{
/* No signals are supported on HS UARTs */
}
/* port->lock is held by caller and interrupts are disabled. */
static unsigned int serial_lpc32xx_get_mctrl(struct uart_port *port)
{
/* No signals are supported on HS UARTs */
return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS;
}
/* port->lock held by caller. */
static void serial_lpc32xx_stop_tx(struct uart_port *port)
{
u32 tmp;
tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
tmp &= ~LPC32XX_HSU_TX_INT_EN;
writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
}
/* port->lock held by caller. */
static void serial_lpc32xx_start_tx(struct uart_port *port)
{
u32 tmp;
__serial_lpc32xx_tx(port);
tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
tmp |= LPC32XX_HSU_TX_INT_EN;
writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
}
/* port->lock held by caller. */
static void serial_lpc32xx_stop_rx(struct uart_port *port)
{
u32 tmp;
tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
writel((LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT |
LPC32XX_HSU_FE_INT), LPC32XX_HSUART_IIR(port->membase));
}
/* port->lock is not held. */
static void serial_lpc32xx_break_ctl(struct uart_port *port,
int break_state)
{
unsigned long flags;
u32 tmp;
spin_lock_irqsave(&port->lock, flags);
tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
if (break_state != 0)
tmp |= LPC32XX_HSU_BREAK;
else
tmp &= ~LPC32XX_HSU_BREAK;
writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
spin_unlock_irqrestore(&port->lock, flags);
}
/* LPC3250 Errata HSUART.1: Hang workaround via loopback mode on inactivity */
static void lpc32xx_loopback_set(resource_size_t mapbase, int state)
{
int bit;
u32 tmp;
switch (mapbase) {
case LPC32XX_HS_UART1_BASE:
bit = 0;
break;
case LPC32XX_HS_UART2_BASE:
bit = 1;
break;
case LPC32XX_HS_UART7_BASE:
bit = 6;
break;
default:
WARN(1, "lpc32xx_hs: Warning: Unknown port at %08x\n", mapbase);
return;
}
tmp = readl(LPC32XX_UARTCTL_CLOOP);
if (state)
tmp |= (1 << bit);
else
tmp &= ~(1 << bit);
writel(tmp, LPC32XX_UARTCTL_CLOOP);
}
/* port->lock is not held. */
static int serial_lpc32xx_startup(struct uart_port *port)
{
int retval;
unsigned long flags;
u32 tmp;
spin_lock_irqsave(&port->lock, flags);
__serial_uart_flush(port);
writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
LPC32XX_HSUART_IIR(port->membase));
writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
/*
* Set receiver timeout, HSU offset of 20, no break, no interrupts,
* and default FIFO trigger levels
*/
tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
lpc32xx_loopback_set(port->mapbase, 0); /* get out of loopback mode */
spin_unlock_irqrestore(&port->lock, flags);
retval = request_irq(port->irq, serial_lpc32xx_interrupt,
0, MODNAME, port);
if (!retval)
writel((tmp | LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN),
LPC32XX_HSUART_CTRL(port->membase));
return retval;
}
/* port->lock is not held. */
static void serial_lpc32xx_shutdown(struct uart_port *port)
{
u32 tmp;
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
tmp = LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B;
writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
lpc32xx_loopback_set(port->mapbase, 1); /* go to loopback mode */
spin_unlock_irqrestore(&port->lock, flags);
free_irq(port->irq, port);
}
/* port->lock is not held. */
static void serial_lpc32xx_set_termios(struct uart_port *port,
struct ktermios *termios,
struct ktermios *old)
{
unsigned long flags;
unsigned int baud, quot;
u32 tmp;
/* Always 8-bit, no parity, 1 stop bit */
termios->c_cflag &= ~(CSIZE | CSTOPB | PARENB | PARODD);
termios->c_cflag |= CS8;
termios->c_cflag &= ~(HUPCL | CMSPAR | CLOCAL | CRTSCTS);
baud = uart_get_baud_rate(port, termios, old, 0,
port->uartclk / 14);
quot = __serial_get_clock_div(port->uartclk, baud);
spin_lock_irqsave(&port->lock, flags);
/* Ignore characters? */
tmp = readl(LPC32XX_HSUART_CTRL(port->membase));
if ((termios->c_cflag & CREAD) == 0)
tmp &= ~(LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN);
else
tmp |= LPC32XX_HSU_RX_INT_EN | LPC32XX_HSU_ERR_INT_EN;
writel(tmp, LPC32XX_HSUART_CTRL(port->membase));
writel(quot, LPC32XX_HSUART_RATE(port->membase));
uart_update_timeout(port, termios->c_cflag, baud);
spin_unlock_irqrestore(&port->lock, flags);
/* Don't rewrite B0 */
if (tty_termios_baud_rate(termios))
tty_termios_encode_baud_rate(termios, baud, baud);
}
static const char *serial_lpc32xx_type(struct uart_port *port)
{
return MODNAME;
}
static void serial_lpc32xx_release_port(struct uart_port *port)
{
if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
if (port->flags & UPF_IOREMAP) {
iounmap(port->membase);
port->membase = NULL;
}
release_mem_region(port->mapbase, SZ_4K);
}
}
static int serial_lpc32xx_request_port(struct uart_port *port)
{
int ret = -ENODEV;
if ((port->iotype == UPIO_MEM32) && (port->mapbase)) {
ret = 0;
if (!request_mem_region(port->mapbase, SZ_4K, MODNAME))
ret = -EBUSY;
else if (port->flags & UPF_IOREMAP) {
port->membase = ioremap(port->mapbase, SZ_4K);
if (!port->membase) {
release_mem_region(port->mapbase, SZ_4K);
ret = -ENOMEM;
}
}
}
return ret;
}
static void serial_lpc32xx_config_port(struct uart_port *port, int uflags)
{
int ret;
ret = serial_lpc32xx_request_port(port);
if (ret < 0)
return;
port->type = PORT_UART00;
port->fifosize = 64;
__serial_uart_flush(port);
writel((LPC32XX_HSU_TX_INT | LPC32XX_HSU_FE_INT |
LPC32XX_HSU_BRK_INT | LPC32XX_HSU_RX_OE_INT),
LPC32XX_HSUART_IIR(port->membase));
writel(0xFF, LPC32XX_HSUART_RATE(port->membase));
/* Set receiver timeout, HSU offset of 20, no break, no interrupts,
and default FIFO trigger levels */
writel(LPC32XX_HSU_TX_TL8B | LPC32XX_HSU_RX_TL32B |
LPC32XX_HSU_OFFSET(20) | LPC32XX_HSU_TMO_INACT_4B,
LPC32XX_HSUART_CTRL(port->membase));
}
static int serial_lpc32xx_verify_port(struct uart_port *port,
struct serial_struct *ser)
{
int ret = 0;
if (ser->type != PORT_UART00)
ret = -EINVAL;
return ret;
}
static struct uart_ops serial_lpc32xx_pops = {
.tx_empty = serial_lpc32xx_tx_empty,
.set_mctrl = serial_lpc32xx_set_mctrl,
.get_mctrl = serial_lpc32xx_get_mctrl,
.stop_tx = serial_lpc32xx_stop_tx,
.start_tx = serial_lpc32xx_start_tx,
.stop_rx = serial_lpc32xx_stop_rx,
.break_ctl = serial_lpc32xx_break_ctl,
.startup = serial_lpc32xx_startup,
.shutdown = serial_lpc32xx_shutdown,
.set_termios = serial_lpc32xx_set_termios,
.type = serial_lpc32xx_type,
.release_port = serial_lpc32xx_release_port,
.request_port = serial_lpc32xx_request_port,
.config_port = serial_lpc32xx_config_port,
.verify_port = serial_lpc32xx_verify_port,
};
/*
* Register a set of serial devices attached to a platform device
*/
static int serial_hs_lpc32xx_probe(struct platform_device *pdev)
{
struct lpc32xx_hsuart_port *p = &lpc32xx_hs_ports[uarts_registered];
int ret = 0;
struct resource *res;
if (uarts_registered >= MAX_PORTS) {
dev_err(&pdev->dev,
"Error: Number of possible ports exceeded (%d)!\n",
uarts_registered + 1);
return -ENXIO;
}
memset(p, 0, sizeof(*p));
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev,
"Error getting mem resource for HS UART port %d\n",
uarts_registered);
return -ENXIO;
}
p->port.mapbase = res->start;
p->port.membase = NULL;
p->port.irq = platform_get_irq(pdev, 0);
if (p->port.irq < 0) {
dev_err(&pdev->dev, "Error getting irq for HS UART port %d\n",
uarts_registered);
return p->port.irq;
}
p->port.iotype = UPIO_MEM32;
p->port.uartclk = LPC32XX_MAIN_OSC_FREQ;
p->port.regshift = 2;
p->port.flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_IOREMAP;
p->port.dev = &pdev->dev;
p->port.ops = &serial_lpc32xx_pops;
p->port.line = uarts_registered++;
spin_lock_init(&p->port.lock);
/* send port to loopback mode by default */
lpc32xx_loopback_set(p->port.mapbase, 1);
ret = uart_add_one_port(&lpc32xx_hs_reg, &p->port);
platform_set_drvdata(pdev, p);
return ret;
}
/*
* Remove serial ports registered against a platform device.
*/
static int serial_hs_lpc32xx_remove(struct platform_device *pdev)
{
struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
uart_remove_one_port(&lpc32xx_hs_reg, &p->port);
return 0;
}
#ifdef CONFIG_PM
static int serial_hs_lpc32xx_suspend(struct platform_device *pdev,
pm_message_t state)
{
struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
uart_suspend_port(&lpc32xx_hs_reg, &p->port);
return 0;
}
static int serial_hs_lpc32xx_resume(struct platform_device *pdev)
{
struct lpc32xx_hsuart_port *p = platform_get_drvdata(pdev);
uart_resume_port(&lpc32xx_hs_reg, &p->port);
return 0;
}
#else
#define serial_hs_lpc32xx_suspend NULL
#define serial_hs_lpc32xx_resume NULL
#endif
static const struct of_device_id serial_hs_lpc32xx_dt_ids[] = {
{ .compatible = "nxp,lpc3220-hsuart" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, serial_hs_lpc32xx_dt_ids);
static struct platform_driver serial_hs_lpc32xx_driver = {
.probe = serial_hs_lpc32xx_probe,
.remove = serial_hs_lpc32xx_remove,
.suspend = serial_hs_lpc32xx_suspend,
.resume = serial_hs_lpc32xx_resume,
.driver = {
.name = MODNAME,
.of_match_table = serial_hs_lpc32xx_dt_ids,
},
};
static int __init lpc32xx_hsuart_init(void)
{
int ret;
ret = uart_register_driver(&lpc32xx_hs_reg);
if (ret)
return ret;
ret = platform_driver_register(&serial_hs_lpc32xx_driver);
if (ret)
uart_unregister_driver(&lpc32xx_hs_reg);
return ret;
}
static void __exit lpc32xx_hsuart_exit(void)
{
platform_driver_unregister(&serial_hs_lpc32xx_driver);
uart_unregister_driver(&lpc32xx_hs_reg);
}
module_init(lpc32xx_hsuart_init);
module_exit(lpc32xx_hsuart_exit);
MODULE_AUTHOR("Kevin Wells <kevin.wells@nxp.com>");
MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
MODULE_DESCRIPTION("NXP LPC32XX High Speed UART driver");
MODULE_LICENSE("GPL");