linux/drivers/tty/serial/bcm63xx_uart.c

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tty: add SPDX identifiers to all remaining files in drivers/tty/ It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the drivers/tty files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Jiri Slaby <jslaby@suse.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Jiri Kosina <jikos@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: James Hogan <jhogan@kernel.org> Cc: Rob Herring <robh@kernel.org> Cc: Eric Anholt <eric@anholt.net> Cc: Stefan Wahren <stefan.wahren@i2se.com> Cc: Florian Fainelli <f.fainelli@gmail.com> Cc: Ray Jui <rjui@broadcom.com> Cc: Scott Branden <sbranden@broadcom.com> Cc: bcm-kernel-feedback-list@broadcom.com Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Joachim Eastwood <manabian@gmail.com> Cc: Matthias Brugger <matthias.bgg@gmail.com> Cc: Masahiro Yamada <yamada.masahiro@socionext.com> Cc: Tobias Klauser <tklauser@distanz.ch> Cc: Russell King <linux@armlinux.org.uk> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Richard Genoud <richard.genoud@gmail.com> Cc: Alexander Shiyan <shc_work@mail.ru> Cc: Baruch Siach <baruch@tkos.co.il> Cc: "Maciej W. Rozycki" <macro@linux-mips.org> Cc: "Uwe Kleine-König" <kernel@pengutronix.de> Cc: Pat Gefre <pfg@sgi.com> Cc: "Guilherme G. Piccoli" <gpiccoli@linux.vnet.ibm.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Vladimir Zapolskiy <vz@mleia.com> Cc: Sylvain Lemieux <slemieux.tyco@gmail.com> Cc: Carlo Caione <carlo@caione.org> Cc: Kevin Hilman <khilman@baylibre.com> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Sudeep Holla <sudeep.holla@arm.com> Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Andy Gross <andy.gross@linaro.org> Cc: David Brown <david.brown@linaro.org> Cc: "Andreas Färber" <afaerber@suse.de> Cc: Kevin Cernekee <cernekee@gmail.com> Cc: Laxman Dewangan <ldewangan@nvidia.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Jonathan Hunter <jonathanh@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Patrice Chotard <patrice.chotard@st.com> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com> Cc: Alexandre Torgue <alexandre.torgue@st.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Peter Korsgaard <jacmet@sunsite.dk> Cc: Timur Tabi <timur@tabi.org> Cc: Tony Prisk <linux@prisktech.co.nz> Cc: Michal Simek <michal.simek@xilinx.com> Cc: "Sören Brinkmann" <soren.brinkmann@xilinx.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Cc: Jiri Slaby <jslaby@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-06 17:11:51 +00:00
// SPDX-License-Identifier: GPL-2.0
/*
* Derived from many drivers using generic_serial interface.
*
* Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
*
* Serial driver for BCM63xx integrated UART.
*
* Hardware flow control was _not_ tested since I only have RX/TX on
* my board.
*/
#if defined(CONFIG_SERIAL_BCM63XX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/console.h>
#include <linux/clk.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/sysrq.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/serial_bcm63xx.h>
#include <linux/io.h>
#include <linux/of.h>
#define BCM63XX_NR_UARTS 2
static struct uart_port ports[BCM63XX_NR_UARTS];
/*
* rx interrupt mask / stat
*
* mask:
* - rx fifo full
* - rx fifo above threshold
* - rx fifo not empty for too long
*/
#define UART_RX_INT_MASK (UART_IR_MASK(UART_IR_RXOVER) | \
UART_IR_MASK(UART_IR_RXTHRESH) | \
UART_IR_MASK(UART_IR_RXTIMEOUT))
#define UART_RX_INT_STAT (UART_IR_STAT(UART_IR_RXOVER) | \
UART_IR_STAT(UART_IR_RXTHRESH) | \
UART_IR_STAT(UART_IR_RXTIMEOUT))
/*
* tx interrupt mask / stat
*
* mask:
* - tx fifo empty
* - tx fifo below threshold
*/
#define UART_TX_INT_MASK (UART_IR_MASK(UART_IR_TXEMPTY) | \
UART_IR_MASK(UART_IR_TXTRESH))
#define UART_TX_INT_STAT (UART_IR_STAT(UART_IR_TXEMPTY) | \
UART_IR_STAT(UART_IR_TXTRESH))
/*
* external input interrupt
*
* mask: any edge on CTS, DCD
*/
#define UART_EXTINP_INT_MASK (UART_EXTINP_IRMASK(UART_EXTINP_IR_CTS) | \
UART_EXTINP_IRMASK(UART_EXTINP_IR_DCD))
/*
* handy uart register accessor
*/
static inline unsigned int bcm_uart_readl(struct uart_port *port,
unsigned int offset)
{
return __raw_readl(port->membase + offset);
}
static inline void bcm_uart_writel(struct uart_port *port,
unsigned int value, unsigned int offset)
{
__raw_writel(value, port->membase + offset);
}
/*
* serial core request to check if uart tx fifo is empty
*/
static unsigned int bcm_uart_tx_empty(struct uart_port *port)
{
unsigned int val;
val = bcm_uart_readl(port, UART_IR_REG);
return (val & UART_IR_STAT(UART_IR_TXEMPTY)) ? 1 : 0;
}
/*
* serial core request to set RTS and DTR pin state and loopback mode
*/
static void bcm_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
unsigned int val;
val = bcm_uart_readl(port, UART_MCTL_REG);
val &= ~(UART_MCTL_DTR_MASK | UART_MCTL_RTS_MASK);
/* invert of written value is reflected on the pin */
if (!(mctrl & TIOCM_DTR))
val |= UART_MCTL_DTR_MASK;
if (!(mctrl & TIOCM_RTS))
val |= UART_MCTL_RTS_MASK;
bcm_uart_writel(port, val, UART_MCTL_REG);
val = bcm_uart_readl(port, UART_CTL_REG);
if (mctrl & TIOCM_LOOP)
val |= UART_CTL_LOOPBACK_MASK;
else
val &= ~UART_CTL_LOOPBACK_MASK;
bcm_uart_writel(port, val, UART_CTL_REG);
}
/*
* serial core request to return RI, CTS, DCD and DSR pin state
*/
static unsigned int bcm_uart_get_mctrl(struct uart_port *port)
{
unsigned int val, mctrl;
mctrl = 0;
val = bcm_uart_readl(port, UART_EXTINP_REG);
if (val & UART_EXTINP_RI_MASK)
mctrl |= TIOCM_RI;
if (val & UART_EXTINP_CTS_MASK)
mctrl |= TIOCM_CTS;
if (val & UART_EXTINP_DCD_MASK)
mctrl |= TIOCM_CD;
if (val & UART_EXTINP_DSR_MASK)
mctrl |= TIOCM_DSR;
return mctrl;
}
/*
* serial core request to disable tx ASAP (used for flow control)
*/
static void bcm_uart_stop_tx(struct uart_port *port)
{
unsigned int val;
val = bcm_uart_readl(port, UART_CTL_REG);
val &= ~(UART_CTL_TXEN_MASK);
bcm_uart_writel(port, val, UART_CTL_REG);
val = bcm_uart_readl(port, UART_IR_REG);
val &= ~UART_TX_INT_MASK;
bcm_uart_writel(port, val, UART_IR_REG);
}
/*
* serial core request to (re)enable tx
*/
static void bcm_uart_start_tx(struct uart_port *port)
{
unsigned int val;
val = bcm_uart_readl(port, UART_IR_REG);
val |= UART_TX_INT_MASK;
bcm_uart_writel(port, val, UART_IR_REG);
val = bcm_uart_readl(port, UART_CTL_REG);
val |= UART_CTL_TXEN_MASK;
bcm_uart_writel(port, val, UART_CTL_REG);
}
/*
* serial core request to stop rx, called before port shutdown
*/
static void bcm_uart_stop_rx(struct uart_port *port)
{
unsigned int val;
val = bcm_uart_readl(port, UART_IR_REG);
val &= ~UART_RX_INT_MASK;
bcm_uart_writel(port, val, UART_IR_REG);
}
/*
* serial core request to enable modem status interrupt reporting
*/
static void bcm_uart_enable_ms(struct uart_port *port)
{
unsigned int val;
val = bcm_uart_readl(port, UART_IR_REG);
val |= UART_IR_MASK(UART_IR_EXTIP);
bcm_uart_writel(port, val, UART_IR_REG);
}
/*
* serial core request to start/stop emitting break char
*/
static void bcm_uart_break_ctl(struct uart_port *port, int ctl)
{
unsigned long flags;
unsigned int val;
spin_lock_irqsave(&port->lock, flags);
val = bcm_uart_readl(port, UART_CTL_REG);
if (ctl)
val |= UART_CTL_XMITBRK_MASK;
else
val &= ~UART_CTL_XMITBRK_MASK;
bcm_uart_writel(port, val, UART_CTL_REG);
spin_unlock_irqrestore(&port->lock, flags);
}
/*
* return port type in string format
*/
static const char *bcm_uart_type(struct uart_port *port)
{
return (port->type == PORT_BCM63XX) ? "bcm63xx_uart" : NULL;
}
/*
* read all chars in rx fifo and send them to core
*/
static void bcm_uart_do_rx(struct uart_port *port)
{
struct tty_port *tty_port = &port->state->port;
unsigned int max_count;
/* limit number of char read in interrupt, should not be
* higher than fifo size anyway since we're much faster than
* serial port */
max_count = 32;
do {
unsigned int iestat, c, cstat;
char flag;
/* get overrun/fifo empty information from ier
* register */
iestat = bcm_uart_readl(port, UART_IR_REG);
if (unlikely(iestat & UART_IR_STAT(UART_IR_RXOVER))) {
unsigned int val;
/* fifo reset is required to clear
* interrupt */
val = bcm_uart_readl(port, UART_CTL_REG);
val |= UART_CTL_RSTRXFIFO_MASK;
bcm_uart_writel(port, val, UART_CTL_REG);
port->icount.overrun++;
tty_insert_flip_char(tty_port, 0, TTY_OVERRUN);
}
if (!(iestat & UART_IR_STAT(UART_IR_RXNOTEMPTY)))
break;
cstat = c = bcm_uart_readl(port, UART_FIFO_REG);
port->icount.rx++;
flag = TTY_NORMAL;
c &= 0xff;
if (unlikely((cstat & UART_FIFO_ANYERR_MASK))) {
/* do stats first */
if (cstat & UART_FIFO_BRKDET_MASK) {
port->icount.brk++;
if (uart_handle_break(port))
continue;
}
if (cstat & UART_FIFO_PARERR_MASK)
port->icount.parity++;
if (cstat & UART_FIFO_FRAMEERR_MASK)
port->icount.frame++;
/* update flag wrt read_status_mask */
cstat &= port->read_status_mask;
if (cstat & UART_FIFO_BRKDET_MASK)
flag = TTY_BREAK;
if (cstat & UART_FIFO_FRAMEERR_MASK)
flag = TTY_FRAME;
if (cstat & UART_FIFO_PARERR_MASK)
flag = TTY_PARITY;
}
if (uart_handle_sysrq_char(port, c))
continue;
if ((cstat & port->ignore_status_mask) == 0)
tty_insert_flip_char(tty_port, c, flag);
} while (--max_count);
tty: serial: bcm63xx: 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 14:44:10 +00:00
spin_unlock(&port->lock);
tty_flip_buffer_push(tty_port);
tty: serial: bcm63xx: 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 14:44:10 +00:00
spin_lock(&port->lock);
}
/*
* fill tx fifo with chars to send, stop when fifo is about to be full
* or when all chars have been sent.
*/
static void bcm_uart_do_tx(struct uart_port *port)
{
struct circ_buf *xmit;
unsigned int val, max_count;
if (port->x_char) {
bcm_uart_writel(port, port->x_char, UART_FIFO_REG);
port->icount.tx++;
port->x_char = 0;
return;
}
if (uart_tx_stopped(port)) {
bcm_uart_stop_tx(port);
return;
}
xmit = &port->state->xmit;
if (uart_circ_empty(xmit))
goto txq_empty;
val = bcm_uart_readl(port, UART_MCTL_REG);
val = (val & UART_MCTL_TXFIFOFILL_MASK) >> UART_MCTL_TXFIFOFILL_SHIFT;
max_count = port->fifosize - val;
while (max_count--) {
unsigned int c;
c = xmit->buf[xmit->tail];
bcm_uart_writel(port, c, UART_FIFO_REG);
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);
if (uart_circ_empty(xmit))
goto txq_empty;
return;
txq_empty:
/* nothing to send, disable transmit interrupt */
val = bcm_uart_readl(port, UART_IR_REG);
val &= ~UART_TX_INT_MASK;
bcm_uart_writel(port, val, UART_IR_REG);
return;
}
/*
* process uart interrupt
*/
static irqreturn_t bcm_uart_interrupt(int irq, void *dev_id)
{
struct uart_port *port;
unsigned int irqstat;
port = dev_id;
spin_lock(&port->lock);
irqstat = bcm_uart_readl(port, UART_IR_REG);
if (irqstat & UART_RX_INT_STAT)
bcm_uart_do_rx(port);
if (irqstat & UART_TX_INT_STAT)
bcm_uart_do_tx(port);
if (irqstat & UART_IR_MASK(UART_IR_EXTIP)) {
unsigned int estat;
estat = bcm_uart_readl(port, UART_EXTINP_REG);
if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_CTS))
uart_handle_cts_change(port,
estat & UART_EXTINP_CTS_MASK);
if (estat & UART_EXTINP_IRSTAT(UART_EXTINP_IR_DCD))
uart_handle_dcd_change(port,
estat & UART_EXTINP_DCD_MASK);
}
spin_unlock(&port->lock);
return IRQ_HANDLED;
}
/*
* enable rx & tx operation on uart
*/
static void bcm_uart_enable(struct uart_port *port)
{
unsigned int val;
val = bcm_uart_readl(port, UART_CTL_REG);
val |= (UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK | UART_CTL_RXEN_MASK);
bcm_uart_writel(port, val, UART_CTL_REG);
}
/*
* disable rx & tx operation on uart
*/
static void bcm_uart_disable(struct uart_port *port)
{
unsigned int val;
val = bcm_uart_readl(port, UART_CTL_REG);
val &= ~(UART_CTL_BRGEN_MASK | UART_CTL_TXEN_MASK |
UART_CTL_RXEN_MASK);
bcm_uart_writel(port, val, UART_CTL_REG);
}
/*
* clear all unread data in rx fifo and unsent data in tx fifo
*/
static void bcm_uart_flush(struct uart_port *port)
{
unsigned int val;
/* empty rx and tx fifo */
val = bcm_uart_readl(port, UART_CTL_REG);
val |= UART_CTL_RSTRXFIFO_MASK | UART_CTL_RSTTXFIFO_MASK;
bcm_uart_writel(port, val, UART_CTL_REG);
/* read any pending char to make sure all irq status are
* cleared */
(void)bcm_uart_readl(port, UART_FIFO_REG);
}
/*
* serial core request to initialize uart and start rx operation
*/
static int bcm_uart_startup(struct uart_port *port)
{
unsigned int val;
int ret;
/* mask all irq and flush port */
bcm_uart_disable(port);
bcm_uart_writel(port, 0, UART_IR_REG);
bcm_uart_flush(port);
/* clear any pending external input interrupt */
(void)bcm_uart_readl(port, UART_EXTINP_REG);
/* set rx/tx fifo thresh to fifo half size */
val = bcm_uart_readl(port, UART_MCTL_REG);
val &= ~(UART_MCTL_RXFIFOTHRESH_MASK | UART_MCTL_TXFIFOTHRESH_MASK);
val |= (port->fifosize / 2) << UART_MCTL_RXFIFOTHRESH_SHIFT;
val |= (port->fifosize / 2) << UART_MCTL_TXFIFOTHRESH_SHIFT;
bcm_uart_writel(port, val, UART_MCTL_REG);
/* set rx fifo timeout to 1 char time */
val = bcm_uart_readl(port, UART_CTL_REG);
val &= ~UART_CTL_RXTMOUTCNT_MASK;
val |= 1 << UART_CTL_RXTMOUTCNT_SHIFT;
bcm_uart_writel(port, val, UART_CTL_REG);
/* report any edge on dcd and cts */
val = UART_EXTINP_INT_MASK;
val |= UART_EXTINP_DCD_NOSENSE_MASK;
val |= UART_EXTINP_CTS_NOSENSE_MASK;
bcm_uart_writel(port, val, UART_EXTINP_REG);
/* register irq and enable rx interrupts */
ret = request_irq(port->irq, bcm_uart_interrupt, 0,
dev_name(port->dev), port);
if (ret)
return ret;
bcm_uart_writel(port, UART_RX_INT_MASK, UART_IR_REG);
bcm_uart_enable(port);
return 0;
}
/*
* serial core request to flush & disable uart
*/
static void bcm_uart_shutdown(struct uart_port *port)
{
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
bcm_uart_writel(port, 0, UART_IR_REG);
spin_unlock_irqrestore(&port->lock, flags);
bcm_uart_disable(port);
bcm_uart_flush(port);
free_irq(port->irq, port);
}
/*
* serial core request to change current uart setting
*/
static void bcm_uart_set_termios(struct uart_port *port,
struct ktermios *new,
struct ktermios *old)
{
unsigned int ctl, baud, quot, ier;
unsigned long flags;
int tries;
spin_lock_irqsave(&port->lock, flags);
/* Drain the hot tub fully before we power it off for the winter. */
for (tries = 3; !bcm_uart_tx_empty(port) && tries; tries--)
mdelay(10);
/* disable uart while changing speed */
bcm_uart_disable(port);
bcm_uart_flush(port);
/* update Control register */
ctl = bcm_uart_readl(port, UART_CTL_REG);
ctl &= ~UART_CTL_BITSPERSYM_MASK;
switch (new->c_cflag & CSIZE) {
case CS5:
ctl |= (0 << UART_CTL_BITSPERSYM_SHIFT);
break;
case CS6:
ctl |= (1 << UART_CTL_BITSPERSYM_SHIFT);
break;
case CS7:
ctl |= (2 << UART_CTL_BITSPERSYM_SHIFT);
break;
default:
ctl |= (3 << UART_CTL_BITSPERSYM_SHIFT);
break;
}
ctl &= ~UART_CTL_STOPBITS_MASK;
if (new->c_cflag & CSTOPB)
ctl |= UART_CTL_STOPBITS_2;
else
ctl |= UART_CTL_STOPBITS_1;
ctl &= ~(UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
if (new->c_cflag & PARENB)
ctl |= (UART_CTL_RXPAREN_MASK | UART_CTL_TXPAREN_MASK);
ctl &= ~(UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
if (new->c_cflag & PARODD)
ctl |= (UART_CTL_RXPAREVEN_MASK | UART_CTL_TXPAREVEN_MASK);
bcm_uart_writel(port, ctl, UART_CTL_REG);
/* update Baudword register */
baud = uart_get_baud_rate(port, new, old, 0, port->uartclk / 16);
quot = uart_get_divisor(port, baud) - 1;
bcm_uart_writel(port, quot, UART_BAUD_REG);
/* update Interrupt register */
ier = bcm_uart_readl(port, UART_IR_REG);
ier &= ~UART_IR_MASK(UART_IR_EXTIP);
if (UART_ENABLE_MS(port, new->c_cflag))
ier |= UART_IR_MASK(UART_IR_EXTIP);
bcm_uart_writel(port, ier, UART_IR_REG);
/* update read/ignore mask */
port->read_status_mask = UART_FIFO_VALID_MASK;
if (new->c_iflag & INPCK) {
port->read_status_mask |= UART_FIFO_FRAMEERR_MASK;
port->read_status_mask |= UART_FIFO_PARERR_MASK;
}
serial: Fix IGNBRK handling If IGNBRK is set without either BRKINT or PARMRK set, some uart drivers send a 0x00 byte for BREAK without the TTYBREAK flag to the line discipline, when it should send either nothing or the TTYBREAK flag set. This happens because the read_status_mask masks out the BI condition, which uart_insert_char() then interprets as a normal 0x00 byte. SUS v3 is clear regarding the meaning of IGNBRK; Section 11.2.2, General Terminal Interface - Input Modes, states: "If IGNBRK is set, a break condition detected on input shall be ignored; that is, not put on the input queue and therefore not read by any process." Fix read_status_mask to include the BI bit if IGNBRK is set; the lsr status retains the BI bit if a BREAK is recv'd, which is subsequently ignored in uart_insert_char() when masked with the ignore_status_mask. Affected drivers: 8250 - all serial_txx9 mfd amba-pl010 amba-pl011 atmel_serial bfin_uart dz ip22zilog max310x mxs-auart netx-serial pnx8xxx_uart pxa sb1250-duart sccnxp serial_ks8695 sirfsoc_uart st-asc vr41xx_siu zs sunzilog fsl_lpuart sunsab ucc_uart bcm63xx_uart sunsu efm32-uart pmac_zilog mpsc msm_serial m32r_sio Unaffected drivers: omap-serial rp2 sa1100 imx icom Annotated for fixes: altera_uart mcf Drivers without break detection: 21285 xilinx-uartps altera_jtaguart apbuart arc-uart clps711x max3100 uartlite msm_serial_hs nwpserial lantiq vt8500_serial Unknown: samsung mpc52xx_uart bfin_sport_uart cpm_uart/core Fixes: Bugzilla #71651, '8250_core.c incorrectly handles IGNBRK flag' Reported-by: Ivan <athlon_@mail.ru> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-06-16 12:10:41 +00:00
if (new->c_iflag & (IGNBRK | BRKINT))
port->read_status_mask |= UART_FIFO_BRKDET_MASK;
port->ignore_status_mask = 0;
if (new->c_iflag & IGNPAR)
port->ignore_status_mask |= UART_FIFO_PARERR_MASK;
if (new->c_iflag & IGNBRK)
port->ignore_status_mask |= UART_FIFO_BRKDET_MASK;
if (!(new->c_cflag & CREAD))
port->ignore_status_mask |= UART_FIFO_VALID_MASK;
uart_update_timeout(port, new->c_cflag, baud);
bcm_uart_enable(port);
spin_unlock_irqrestore(&port->lock, flags);
}
/*
* serial core request to claim uart iomem
*/
static int bcm_uart_request_port(struct uart_port *port)
{
/* UARTs always present */
return 0;
}
/*
* serial core request to release uart iomem
*/
static void bcm_uart_release_port(struct uart_port *port)
{
/* Nothing to release ... */
}
/*
* serial core request to do any port required autoconfiguration
*/
static void bcm_uart_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE) {
if (bcm_uart_request_port(port))
return;
port->type = PORT_BCM63XX;
}
}
/*
* serial core request to check that port information in serinfo are
* suitable
*/
static int bcm_uart_verify_port(struct uart_port *port,
struct serial_struct *serinfo)
{
if (port->type != PORT_BCM63XX)
return -EINVAL;
if (port->irq != serinfo->irq)
return -EINVAL;
if (port->iotype != serinfo->io_type)
return -EINVAL;
if (port->mapbase != (unsigned long)serinfo->iomem_base)
return -EINVAL;
return 0;
}
/* serial core callbacks */
static const struct uart_ops bcm_uart_ops = {
.tx_empty = bcm_uart_tx_empty,
.get_mctrl = bcm_uart_get_mctrl,
.set_mctrl = bcm_uart_set_mctrl,
.start_tx = bcm_uart_start_tx,
.stop_tx = bcm_uart_stop_tx,
.stop_rx = bcm_uart_stop_rx,
.enable_ms = bcm_uart_enable_ms,
.break_ctl = bcm_uart_break_ctl,
.startup = bcm_uart_startup,
.shutdown = bcm_uart_shutdown,
.set_termios = bcm_uart_set_termios,
.type = bcm_uart_type,
.release_port = bcm_uart_release_port,
.request_port = bcm_uart_request_port,
.config_port = bcm_uart_config_port,
.verify_port = bcm_uart_verify_port,
};
#ifdef CONFIG_SERIAL_BCM63XX_CONSOLE
static void wait_for_xmitr(struct uart_port *port)
{
unsigned int tmout;
/* Wait up to 10ms for the character(s) to be sent. */
tmout = 10000;
while (--tmout) {
unsigned int val;
val = bcm_uart_readl(port, UART_IR_REG);
if (val & UART_IR_STAT(UART_IR_TXEMPTY))
break;
udelay(1);
}
/* Wait up to 1s for flow control if necessary */
if (port->flags & UPF_CONS_FLOW) {
tmout = 1000000;
while (--tmout) {
unsigned int val;
val = bcm_uart_readl(port, UART_EXTINP_REG);
if (val & UART_EXTINP_CTS_MASK)
break;
udelay(1);
}
}
}
/*
* output given char
*/
static void bcm_console_putchar(struct uart_port *port, int ch)
{
wait_for_xmitr(port);
bcm_uart_writel(port, ch, UART_FIFO_REG);
}
/*
* console core request to output given string
*/
static void bcm_console_write(struct console *co, const char *s,
unsigned int count)
{
struct uart_port *port;
unsigned long flags;
int locked;
port = &ports[co->index];
local_irq_save(flags);
if (port->sysrq) {
/* bcm_uart_interrupt() already took the lock */
locked = 0;
} else if (oops_in_progress) {
locked = spin_trylock(&port->lock);
} else {
spin_lock(&port->lock);
locked = 1;
}
/* call helper to deal with \r\n */
uart_console_write(port, s, count, bcm_console_putchar);
/* and wait for char to be transmitted */
wait_for_xmitr(port);
if (locked)
spin_unlock(&port->lock);
local_irq_restore(flags);
}
/*
* console core request to setup given console, find matching uart
* port and setup it.
*/
static int bcm_console_setup(struct console *co, char *options)
{
struct uart_port *port;
int baud = 9600;
int bits = 8;
int parity = 'n';
int flow = 'n';
if (co->index < 0 || co->index >= BCM63XX_NR_UARTS)
return -EINVAL;
port = &ports[co->index];
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 bcm_uart_driver;
static struct console bcm63xx_console = {
.name = "ttyS",
.write = bcm_console_write,
.device = uart_console_device,
.setup = bcm_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &bcm_uart_driver,
};
static int __init bcm63xx_console_init(void)
{
register_console(&bcm63xx_console);
return 0;
}
console_initcall(bcm63xx_console_init);
static void bcm_early_write(struct console *con, const char *s, unsigned n)
{
struct earlycon_device *dev = con->data;
uart_console_write(&dev->port, s, n, bcm_console_putchar);
wait_for_xmitr(&dev->port);
}
static int __init bcm_early_console_setup(struct earlycon_device *device,
const char *opt)
{
if (!device->port.membase)
return -ENODEV;
device->con->write = bcm_early_write;
return 0;
}
OF_EARLYCON_DECLARE(bcm63xx_uart, "brcm,bcm6345-uart", bcm_early_console_setup);
#define BCM63XX_CONSOLE (&bcm63xx_console)
#else
#define BCM63XX_CONSOLE NULL
#endif /* CONFIG_SERIAL_BCM63XX_CONSOLE */
static struct uart_driver bcm_uart_driver = {
.owner = THIS_MODULE,
.driver_name = "bcm63xx_uart",
.dev_name = "ttyS",
.major = TTY_MAJOR,
.minor = 64,
.nr = BCM63XX_NR_UARTS,
.cons = BCM63XX_CONSOLE,
};
/*
* platform driver probe/remove callback
*/
static int bcm_uart_probe(struct platform_device *pdev)
{
struct resource *res_mem, *res_irq;
struct uart_port *port;
struct clk *clk;
int ret;
if (pdev->dev.of_node) {
pdev->id = of_alias_get_id(pdev->dev.of_node, "serial");
if (pdev->id < 0)
pdev->id = of_alias_get_id(pdev->dev.of_node, "uart");
}
if (pdev->id < 0 || pdev->id >= BCM63XX_NR_UARTS)
return -EINVAL;
port = &ports[pdev->id];
if (port->membase)
return -EBUSY;
memset(port, 0, sizeof(*port));
res_mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res_mem)
return -ENODEV;
port->mapbase = res_mem->start;
port->membase = devm_ioremap_resource(&pdev->dev, res_mem);
if (IS_ERR(port->membase))
return PTR_ERR(port->membase);
res_irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!res_irq)
return -ENODEV;
clk = clk_get(&pdev->dev, "refclk");
if (IS_ERR(clk) && pdev->dev.of_node)
clk = of_clk_get(pdev->dev.of_node, 0);
if (IS_ERR(clk))
return -ENODEV;
port->iotype = UPIO_MEM;
port->irq = res_irq->start;
port->ops = &bcm_uart_ops;
port->flags = UPF_BOOT_AUTOCONF;
port->dev = &pdev->dev;
port->fifosize = 16;
port->uartclk = clk_get_rate(clk) / 2;
port->line = pdev->id;
clk_put(clk);
ret = uart_add_one_port(&bcm_uart_driver, port);
if (ret) {
ports[pdev->id].membase = NULL;
return ret;
}
platform_set_drvdata(pdev, port);
return 0;
}
static int bcm_uart_remove(struct platform_device *pdev)
{
struct uart_port *port;
port = platform_get_drvdata(pdev);
uart_remove_one_port(&bcm_uart_driver, port);
/* mark port as free */
ports[pdev->id].membase = NULL;
return 0;
}
static const struct of_device_id bcm63xx_of_match[] = {
{ .compatible = "brcm,bcm6345-uart" },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, bcm63xx_of_match);
/*
* platform driver stuff
*/
static struct platform_driver bcm_uart_platform_driver = {
.probe = bcm_uart_probe,
.remove = bcm_uart_remove,
.driver = {
.name = "bcm63xx_uart",
.of_match_table = bcm63xx_of_match,
},
};
static int __init bcm_uart_init(void)
{
int ret;
ret = uart_register_driver(&bcm_uart_driver);
if (ret)
return ret;
ret = platform_driver_register(&bcm_uart_platform_driver);
if (ret)
uart_unregister_driver(&bcm_uart_driver);
return ret;
}
static void __exit bcm_uart_exit(void)
{
platform_driver_unregister(&bcm_uart_platform_driver);
uart_unregister_driver(&bcm_uart_driver);
}
module_init(bcm_uart_init);
module_exit(bcm_uart_exit);
MODULE_AUTHOR("Maxime Bizon <mbizon@freebox.fr>");
MODULE_DESCRIPTION("Broadcom 63xx integrated uart driver");
MODULE_LICENSE("GPL");