linux/drivers/tty/serial/ar933x_uart.c

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/*
* Atheros AR933X SoC built-in UART driver
*
* Copyright (C) 2011 Gabor Juhos <juhosg@openwrt.org>
*
* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/delay.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial_core.h>
#include <linux/serial.h>
#include <linux/slab.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/clk.h>
tty/serial/ar933x_uart: fix baud rate calculation The UART of the AR933x SoC implements a fractional divisor for generating the desired baud rate. The current code uses a fixed value for the fractional part of the divisor, and this leads to improperly calculated baud rates: baud scale step real baud diff 300 5207* 8192 17756 17456 5818.66% 600 2603* 8192 35511 34911 5818.50% 1200 1301* 8192 71023 69823 5818.58% 2400 650* 8192 11241 8841 368.37% 4800 324* 8192 22645 17845 371.77% 9600 161 8192 9645 45 0.46% 14400 107 8192 14468 68 0.47% 19200 80 8192 19290 90 0.46% 28800 53 8192 28935 135 0.46% 38400 39 8192 39063 663 1.72% 57600 26 8192 57870 270 0.46% 115200 12 8192 120192 4992 4.33% 230400 5 8192 260417 30017 13.02% 460800 2 8192 520833 60033 13.02% 921600 0 8192 1562500 640900 69.93% After the patch, the integer and fractional parts of the divisor will be calculated dynamically. This ensures that the UART will use correct baud rates: baud scale step real baud diff 300 6 11 300 0 0.00% 600 54 173 600 0 0.00% 1200 30 195 1200 0 0.00% 2400 30 390 2400 0 0.00% 4800 48 1233 4800 0 0.00% 9600 78 3976 9600 0 0.00% 14400 98 7474 14400 0 0.00% 19200 55 5637 19200 0 0.00% 28800 130 19780 28800 0 0.00% 38400 36 7449 38400 0 0.00% 57600 78 23857 57600 0 0.00% 115200 43 26575 115200 0 0.00% 230400 23 28991 230400 0 0.00% 460800 11 28991 460800 0 0.00% 921600 5 28991 921599 -1 0.00% Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14 09:38:13 +00:00
#include <asm/div64.h>
#include <asm/mach-ath79/ar933x_uart.h>
#define DRIVER_NAME "ar933x-uart"
tty/serial/ar933x_uart: fix baud rate calculation The UART of the AR933x SoC implements a fractional divisor for generating the desired baud rate. The current code uses a fixed value for the fractional part of the divisor, and this leads to improperly calculated baud rates: baud scale step real baud diff 300 5207* 8192 17756 17456 5818.66% 600 2603* 8192 35511 34911 5818.50% 1200 1301* 8192 71023 69823 5818.58% 2400 650* 8192 11241 8841 368.37% 4800 324* 8192 22645 17845 371.77% 9600 161 8192 9645 45 0.46% 14400 107 8192 14468 68 0.47% 19200 80 8192 19290 90 0.46% 28800 53 8192 28935 135 0.46% 38400 39 8192 39063 663 1.72% 57600 26 8192 57870 270 0.46% 115200 12 8192 120192 4992 4.33% 230400 5 8192 260417 30017 13.02% 460800 2 8192 520833 60033 13.02% 921600 0 8192 1562500 640900 69.93% After the patch, the integer and fractional parts of the divisor will be calculated dynamically. This ensures that the UART will use correct baud rates: baud scale step real baud diff 300 6 11 300 0 0.00% 600 54 173 600 0 0.00% 1200 30 195 1200 0 0.00% 2400 30 390 2400 0 0.00% 4800 48 1233 4800 0 0.00% 9600 78 3976 9600 0 0.00% 14400 98 7474 14400 0 0.00% 19200 55 5637 19200 0 0.00% 28800 130 19780 28800 0 0.00% 38400 36 7449 38400 0 0.00% 57600 78 23857 57600 0 0.00% 115200 43 26575 115200 0 0.00% 230400 23 28991 230400 0 0.00% 460800 11 28991 460800 0 0.00% 921600 5 28991 921599 -1 0.00% Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14 09:38:13 +00:00
#define AR933X_UART_MAX_SCALE 0xff
#define AR933X_UART_MAX_STEP 0xffff
#define AR933X_UART_MIN_BAUD 300
#define AR933X_UART_MAX_BAUD 3000000
#define AR933X_DUMMY_STATUS_RD 0x01
static struct uart_driver ar933x_uart_driver;
struct ar933x_uart_port {
struct uart_port port;
unsigned int ier; /* shadow Interrupt Enable Register */
tty/serial/ar933x_uart: fix baud rate calculation The UART of the AR933x SoC implements a fractional divisor for generating the desired baud rate. The current code uses a fixed value for the fractional part of the divisor, and this leads to improperly calculated baud rates: baud scale step real baud diff 300 5207* 8192 17756 17456 5818.66% 600 2603* 8192 35511 34911 5818.50% 1200 1301* 8192 71023 69823 5818.58% 2400 650* 8192 11241 8841 368.37% 4800 324* 8192 22645 17845 371.77% 9600 161 8192 9645 45 0.46% 14400 107 8192 14468 68 0.47% 19200 80 8192 19290 90 0.46% 28800 53 8192 28935 135 0.46% 38400 39 8192 39063 663 1.72% 57600 26 8192 57870 270 0.46% 115200 12 8192 120192 4992 4.33% 230400 5 8192 260417 30017 13.02% 460800 2 8192 520833 60033 13.02% 921600 0 8192 1562500 640900 69.93% After the patch, the integer and fractional parts of the divisor will be calculated dynamically. This ensures that the UART will use correct baud rates: baud scale step real baud diff 300 6 11 300 0 0.00% 600 54 173 600 0 0.00% 1200 30 195 1200 0 0.00% 2400 30 390 2400 0 0.00% 4800 48 1233 4800 0 0.00% 9600 78 3976 9600 0 0.00% 14400 98 7474 14400 0 0.00% 19200 55 5637 19200 0 0.00% 28800 130 19780 28800 0 0.00% 38400 36 7449 38400 0 0.00% 57600 78 23857 57600 0 0.00% 115200 43 26575 115200 0 0.00% 230400 23 28991 230400 0 0.00% 460800 11 28991 460800 0 0.00% 921600 5 28991 921599 -1 0.00% Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14 09:38:13 +00:00
unsigned int min_baud;
unsigned int max_baud;
struct clk *clk;
};
static inline bool ar933x_uart_console_enabled(void)
{
tree-wide: replace config_enabled() with IS_ENABLED() The use of config_enabled() against config options is ambiguous. In practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the author might have used it for the meaning of IS_ENABLED(). Using IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc. makes the intention clearer. This commit replaces config_enabled() with IS_ENABLED() where possible. This commit is only touching bool config options. I noticed two cases where config_enabled() is used against a tristate option: - config_enabled(CONFIG_HWMON) [ drivers/net/wireless/ath/ath10k/thermal.c ] - config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE) [ drivers/gpu/drm/gma500/opregion.c ] I did not touch them because they should be converted to IS_BUILTIN() in order to keep the logic, but I was not sure it was the authors' intention. Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Stas Sergeev <stsp@list.ru> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Joshua Kinard <kumba@gentoo.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov <bp@suse.de> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: "Dmitry V. Levin" <ldv@altlinux.org> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Will Drewry <wad@chromium.org> Cc: Nikolay Martynov <mar.kolya@gmail.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: Rafal Milecki <zajec5@gmail.com> Cc: James Cowgill <James.Cowgill@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Qais Yousef <qais.yousef@imgtec.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Mikko Rapeli <mikko.rapeli@iki.fi> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: "Luis R. Rodriguez" <mcgrof@do-not-panic.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Kalle Valo <kvalo@qca.qualcomm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Tony Wu <tung7970@gmail.com> Cc: Huaitong Han <huaitong.han@intel.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Juergen Gross <jgross@suse.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Rabin Vincent <rabin@rab.in> Cc: "Maciej W. Rozycki" <macro@imgtec.com> Cc: David Daney <david.daney@cavium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-03 20:45:50 +00:00
return IS_ENABLED(CONFIG_SERIAL_AR933X_CONSOLE);
}
static inline unsigned int ar933x_uart_read(struct ar933x_uart_port *up,
int offset)
{
return readl(up->port.membase + offset);
}
static inline void ar933x_uart_write(struct ar933x_uart_port *up,
int offset, unsigned int value)
{
writel(value, up->port.membase + offset);
}
static inline void ar933x_uart_rmw(struct ar933x_uart_port *up,
unsigned int offset,
unsigned int mask,
unsigned int val)
{
unsigned int t;
t = ar933x_uart_read(up, offset);
t &= ~mask;
t |= val;
ar933x_uart_write(up, offset, t);
}
static inline void ar933x_uart_rmw_set(struct ar933x_uart_port *up,
unsigned int offset,
unsigned int val)
{
ar933x_uart_rmw(up, offset, 0, val);
}
static inline void ar933x_uart_rmw_clear(struct ar933x_uart_port *up,
unsigned int offset,
unsigned int val)
{
ar933x_uart_rmw(up, offset, val, 0);
}
static inline void ar933x_uart_start_tx_interrupt(struct ar933x_uart_port *up)
{
up->ier |= AR933X_UART_INT_TX_EMPTY;
ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
}
static inline void ar933x_uart_stop_tx_interrupt(struct ar933x_uart_port *up)
{
up->ier &= ~AR933X_UART_INT_TX_EMPTY;
ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
}
static inline void ar933x_uart_putc(struct ar933x_uart_port *up, int ch)
{
unsigned int rdata;
rdata = ch & AR933X_UART_DATA_TX_RX_MASK;
rdata |= AR933X_UART_DATA_TX_CSR;
ar933x_uart_write(up, AR933X_UART_DATA_REG, rdata);
}
static unsigned int ar933x_uart_tx_empty(struct uart_port *port)
{
struct ar933x_uart_port *up =
container_of(port, struct ar933x_uart_port, port);
unsigned long flags;
unsigned int rdata;
spin_lock_irqsave(&up->port.lock, flags);
rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
spin_unlock_irqrestore(&up->port.lock, flags);
return (rdata & AR933X_UART_DATA_TX_CSR) ? 0 : TIOCSER_TEMT;
}
static unsigned int ar933x_uart_get_mctrl(struct uart_port *port)
{
return TIOCM_CAR;
}
static void ar933x_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
}
static void ar933x_uart_start_tx(struct uart_port *port)
{
struct ar933x_uart_port *up =
container_of(port, struct ar933x_uart_port, port);
ar933x_uart_start_tx_interrupt(up);
}
static void ar933x_uart_stop_tx(struct uart_port *port)
{
struct ar933x_uart_port *up =
container_of(port, struct ar933x_uart_port, port);
ar933x_uart_stop_tx_interrupt(up);
}
static void ar933x_uart_stop_rx(struct uart_port *port)
{
struct ar933x_uart_port *up =
container_of(port, struct ar933x_uart_port, port);
up->ier &= ~AR933X_UART_INT_RX_VALID;
ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
}
static void ar933x_uart_break_ctl(struct uart_port *port, int break_state)
{
struct ar933x_uart_port *up =
container_of(port, struct ar933x_uart_port, port);
unsigned long flags;
spin_lock_irqsave(&up->port.lock, flags);
if (break_state == -1)
ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
AR933X_UART_CS_TX_BREAK);
else
ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
AR933X_UART_CS_TX_BREAK);
spin_unlock_irqrestore(&up->port.lock, flags);
}
tty/serial/ar933x_uart: fix baud rate calculation The UART of the AR933x SoC implements a fractional divisor for generating the desired baud rate. The current code uses a fixed value for the fractional part of the divisor, and this leads to improperly calculated baud rates: baud scale step real baud diff 300 5207* 8192 17756 17456 5818.66% 600 2603* 8192 35511 34911 5818.50% 1200 1301* 8192 71023 69823 5818.58% 2400 650* 8192 11241 8841 368.37% 4800 324* 8192 22645 17845 371.77% 9600 161 8192 9645 45 0.46% 14400 107 8192 14468 68 0.47% 19200 80 8192 19290 90 0.46% 28800 53 8192 28935 135 0.46% 38400 39 8192 39063 663 1.72% 57600 26 8192 57870 270 0.46% 115200 12 8192 120192 4992 4.33% 230400 5 8192 260417 30017 13.02% 460800 2 8192 520833 60033 13.02% 921600 0 8192 1562500 640900 69.93% After the patch, the integer and fractional parts of the divisor will be calculated dynamically. This ensures that the UART will use correct baud rates: baud scale step real baud diff 300 6 11 300 0 0.00% 600 54 173 600 0 0.00% 1200 30 195 1200 0 0.00% 2400 30 390 2400 0 0.00% 4800 48 1233 4800 0 0.00% 9600 78 3976 9600 0 0.00% 14400 98 7474 14400 0 0.00% 19200 55 5637 19200 0 0.00% 28800 130 19780 28800 0 0.00% 38400 36 7449 38400 0 0.00% 57600 78 23857 57600 0 0.00% 115200 43 26575 115200 0 0.00% 230400 23 28991 230400 0 0.00% 460800 11 28991 460800 0 0.00% 921600 5 28991 921599 -1 0.00% Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14 09:38:13 +00:00
/*
* baudrate = (clk / (scale + 1)) * (step * (1 / 2^17))
*/
static unsigned long ar933x_uart_get_baud(unsigned int clk,
unsigned int scale,
unsigned int step)
{
u64 t;
u32 div;
div = (2 << 16) * (scale + 1);
t = clk;
t *= step;
t += (div / 2);
do_div(t, div);
return t;
}
static void ar933x_uart_get_scale_step(unsigned int clk,
unsigned int baud,
unsigned int *scale,
unsigned int *step)
{
unsigned int tscale;
long min_diff;
*scale = 0;
*step = 0;
min_diff = baud;
for (tscale = 0; tscale < AR933X_UART_MAX_SCALE; tscale++) {
u64 tstep;
int diff;
tstep = baud * (tscale + 1);
tstep *= (2 << 16);
do_div(tstep, clk);
if (tstep > AR933X_UART_MAX_STEP)
break;
diff = abs(ar933x_uart_get_baud(clk, tscale, tstep) - baud);
if (diff < min_diff) {
min_diff = diff;
*scale = tscale;
*step = tstep;
}
}
}
static void ar933x_uart_set_termios(struct uart_port *port,
struct ktermios *new,
struct ktermios *old)
{
struct ar933x_uart_port *up =
container_of(port, struct ar933x_uart_port, port);
unsigned int cs;
unsigned long flags;
tty/serial/ar933x_uart: fix baud rate calculation The UART of the AR933x SoC implements a fractional divisor for generating the desired baud rate. The current code uses a fixed value for the fractional part of the divisor, and this leads to improperly calculated baud rates: baud scale step real baud diff 300 5207* 8192 17756 17456 5818.66% 600 2603* 8192 35511 34911 5818.50% 1200 1301* 8192 71023 69823 5818.58% 2400 650* 8192 11241 8841 368.37% 4800 324* 8192 22645 17845 371.77% 9600 161 8192 9645 45 0.46% 14400 107 8192 14468 68 0.47% 19200 80 8192 19290 90 0.46% 28800 53 8192 28935 135 0.46% 38400 39 8192 39063 663 1.72% 57600 26 8192 57870 270 0.46% 115200 12 8192 120192 4992 4.33% 230400 5 8192 260417 30017 13.02% 460800 2 8192 520833 60033 13.02% 921600 0 8192 1562500 640900 69.93% After the patch, the integer and fractional parts of the divisor will be calculated dynamically. This ensures that the UART will use correct baud rates: baud scale step real baud diff 300 6 11 300 0 0.00% 600 54 173 600 0 0.00% 1200 30 195 1200 0 0.00% 2400 30 390 2400 0 0.00% 4800 48 1233 4800 0 0.00% 9600 78 3976 9600 0 0.00% 14400 98 7474 14400 0 0.00% 19200 55 5637 19200 0 0.00% 28800 130 19780 28800 0 0.00% 38400 36 7449 38400 0 0.00% 57600 78 23857 57600 0 0.00% 115200 43 26575 115200 0 0.00% 230400 23 28991 230400 0 0.00% 460800 11 28991 460800 0 0.00% 921600 5 28991 921599 -1 0.00% Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14 09:38:13 +00:00
unsigned int baud, scale, step;
/* Only CS8 is supported */
new->c_cflag &= ~CSIZE;
new->c_cflag |= CS8;
/* Only one stop bit is supported */
new->c_cflag &= ~CSTOPB;
cs = 0;
if (new->c_cflag & PARENB) {
if (!(new->c_cflag & PARODD))
cs |= AR933X_UART_CS_PARITY_EVEN;
else
cs |= AR933X_UART_CS_PARITY_ODD;
} else {
cs |= AR933X_UART_CS_PARITY_NONE;
}
/* Mark/space parity is not supported */
new->c_cflag &= ~CMSPAR;
tty/serial/ar933x_uart: fix baud rate calculation The UART of the AR933x SoC implements a fractional divisor for generating the desired baud rate. The current code uses a fixed value for the fractional part of the divisor, and this leads to improperly calculated baud rates: baud scale step real baud diff 300 5207* 8192 17756 17456 5818.66% 600 2603* 8192 35511 34911 5818.50% 1200 1301* 8192 71023 69823 5818.58% 2400 650* 8192 11241 8841 368.37% 4800 324* 8192 22645 17845 371.77% 9600 161 8192 9645 45 0.46% 14400 107 8192 14468 68 0.47% 19200 80 8192 19290 90 0.46% 28800 53 8192 28935 135 0.46% 38400 39 8192 39063 663 1.72% 57600 26 8192 57870 270 0.46% 115200 12 8192 120192 4992 4.33% 230400 5 8192 260417 30017 13.02% 460800 2 8192 520833 60033 13.02% 921600 0 8192 1562500 640900 69.93% After the patch, the integer and fractional parts of the divisor will be calculated dynamically. This ensures that the UART will use correct baud rates: baud scale step real baud diff 300 6 11 300 0 0.00% 600 54 173 600 0 0.00% 1200 30 195 1200 0 0.00% 2400 30 390 2400 0 0.00% 4800 48 1233 4800 0 0.00% 9600 78 3976 9600 0 0.00% 14400 98 7474 14400 0 0.00% 19200 55 5637 19200 0 0.00% 28800 130 19780 28800 0 0.00% 38400 36 7449 38400 0 0.00% 57600 78 23857 57600 0 0.00% 115200 43 26575 115200 0 0.00% 230400 23 28991 230400 0 0.00% 460800 11 28991 460800 0 0.00% 921600 5 28991 921599 -1 0.00% Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14 09:38:13 +00:00
baud = uart_get_baud_rate(port, new, old, up->min_baud, up->max_baud);
ar933x_uart_get_scale_step(port->uartclk, baud, &scale, &step);
/*
* Ok, we're now changing the port state. Do it with
* interrupts disabled.
*/
spin_lock_irqsave(&up->port.lock, flags);
tty/serial/ar933x_uart: fix baud rate calculation The UART of the AR933x SoC implements a fractional divisor for generating the desired baud rate. The current code uses a fixed value for the fractional part of the divisor, and this leads to improperly calculated baud rates: baud scale step real baud diff 300 5207* 8192 17756 17456 5818.66% 600 2603* 8192 35511 34911 5818.50% 1200 1301* 8192 71023 69823 5818.58% 2400 650* 8192 11241 8841 368.37% 4800 324* 8192 22645 17845 371.77% 9600 161 8192 9645 45 0.46% 14400 107 8192 14468 68 0.47% 19200 80 8192 19290 90 0.46% 28800 53 8192 28935 135 0.46% 38400 39 8192 39063 663 1.72% 57600 26 8192 57870 270 0.46% 115200 12 8192 120192 4992 4.33% 230400 5 8192 260417 30017 13.02% 460800 2 8192 520833 60033 13.02% 921600 0 8192 1562500 640900 69.93% After the patch, the integer and fractional parts of the divisor will be calculated dynamically. This ensures that the UART will use correct baud rates: baud scale step real baud diff 300 6 11 300 0 0.00% 600 54 173 600 0 0.00% 1200 30 195 1200 0 0.00% 2400 30 390 2400 0 0.00% 4800 48 1233 4800 0 0.00% 9600 78 3976 9600 0 0.00% 14400 98 7474 14400 0 0.00% 19200 55 5637 19200 0 0.00% 28800 130 19780 28800 0 0.00% 38400 36 7449 38400 0 0.00% 57600 78 23857 57600 0 0.00% 115200 43 26575 115200 0 0.00% 230400 23 28991 230400 0 0.00% 460800 11 28991 460800 0 0.00% 921600 5 28991 921599 -1 0.00% Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14 09:38:13 +00:00
/* disable the UART */
ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S);
/* Update the per-port timeout. */
uart_update_timeout(port, new->c_cflag, baud);
up->port.ignore_status_mask = 0;
/* ignore all characters if CREAD is not set */
if ((new->c_cflag & CREAD) == 0)
up->port.ignore_status_mask |= AR933X_DUMMY_STATUS_RD;
ar933x_uart_write(up, AR933X_UART_CLOCK_REG,
tty/serial/ar933x_uart: fix baud rate calculation The UART of the AR933x SoC implements a fractional divisor for generating the desired baud rate. The current code uses a fixed value for the fractional part of the divisor, and this leads to improperly calculated baud rates: baud scale step real baud diff 300 5207* 8192 17756 17456 5818.66% 600 2603* 8192 35511 34911 5818.50% 1200 1301* 8192 71023 69823 5818.58% 2400 650* 8192 11241 8841 368.37% 4800 324* 8192 22645 17845 371.77% 9600 161 8192 9645 45 0.46% 14400 107 8192 14468 68 0.47% 19200 80 8192 19290 90 0.46% 28800 53 8192 28935 135 0.46% 38400 39 8192 39063 663 1.72% 57600 26 8192 57870 270 0.46% 115200 12 8192 120192 4992 4.33% 230400 5 8192 260417 30017 13.02% 460800 2 8192 520833 60033 13.02% 921600 0 8192 1562500 640900 69.93% After the patch, the integer and fractional parts of the divisor will be calculated dynamically. This ensures that the UART will use correct baud rates: baud scale step real baud diff 300 6 11 300 0 0.00% 600 54 173 600 0 0.00% 1200 30 195 1200 0 0.00% 2400 30 390 2400 0 0.00% 4800 48 1233 4800 0 0.00% 9600 78 3976 9600 0 0.00% 14400 98 7474 14400 0 0.00% 19200 55 5637 19200 0 0.00% 28800 130 19780 28800 0 0.00% 38400 36 7449 38400 0 0.00% 57600 78 23857 57600 0 0.00% 115200 43 26575 115200 0 0.00% 230400 23 28991 230400 0 0.00% 460800 11 28991 460800 0 0.00% 921600 5 28991 921599 -1 0.00% Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14 09:38:13 +00:00
scale << AR933X_UART_CLOCK_SCALE_S | step);
/* setup configuration register */
ar933x_uart_rmw(up, AR933X_UART_CS_REG, AR933X_UART_CS_PARITY_M, cs);
/* enable host interrupt */
ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
AR933X_UART_CS_HOST_INT_EN);
tty/serial/ar933x_uart: fix baud rate calculation The UART of the AR933x SoC implements a fractional divisor for generating the desired baud rate. The current code uses a fixed value for the fractional part of the divisor, and this leads to improperly calculated baud rates: baud scale step real baud diff 300 5207* 8192 17756 17456 5818.66% 600 2603* 8192 35511 34911 5818.50% 1200 1301* 8192 71023 69823 5818.58% 2400 650* 8192 11241 8841 368.37% 4800 324* 8192 22645 17845 371.77% 9600 161 8192 9645 45 0.46% 14400 107 8192 14468 68 0.47% 19200 80 8192 19290 90 0.46% 28800 53 8192 28935 135 0.46% 38400 39 8192 39063 663 1.72% 57600 26 8192 57870 270 0.46% 115200 12 8192 120192 4992 4.33% 230400 5 8192 260417 30017 13.02% 460800 2 8192 520833 60033 13.02% 921600 0 8192 1562500 640900 69.93% After the patch, the integer and fractional parts of the divisor will be calculated dynamically. This ensures that the UART will use correct baud rates: baud scale step real baud diff 300 6 11 300 0 0.00% 600 54 173 600 0 0.00% 1200 30 195 1200 0 0.00% 2400 30 390 2400 0 0.00% 4800 48 1233 4800 0 0.00% 9600 78 3976 9600 0 0.00% 14400 98 7474 14400 0 0.00% 19200 55 5637 19200 0 0.00% 28800 130 19780 28800 0 0.00% 38400 36 7449 38400 0 0.00% 57600 78 23857 57600 0 0.00% 115200 43 26575 115200 0 0.00% 230400 23 28991 230400 0 0.00% 460800 11 28991 460800 0 0.00% 921600 5 28991 921599 -1 0.00% Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14 09:38:13 +00:00
/* reenable the UART */
ar933x_uart_rmw(up, AR933X_UART_CS_REG,
AR933X_UART_CS_IF_MODE_M << AR933X_UART_CS_IF_MODE_S,
AR933X_UART_CS_IF_MODE_DCE << AR933X_UART_CS_IF_MODE_S);
spin_unlock_irqrestore(&up->port.lock, flags);
if (tty_termios_baud_rate(new))
tty_termios_encode_baud_rate(new, baud, baud);
}
static void ar933x_uart_rx_chars(struct ar933x_uart_port *up)
{
struct tty_port *port = &up->port.state->port;
int max_count = 256;
do {
unsigned int rdata;
unsigned char ch;
rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
if ((rdata & AR933X_UART_DATA_RX_CSR) == 0)
break;
/* remove the character from the FIFO */
ar933x_uart_write(up, AR933X_UART_DATA_REG,
AR933X_UART_DATA_RX_CSR);
up->port.icount.rx++;
ch = rdata & AR933X_UART_DATA_TX_RX_MASK;
if (uart_handle_sysrq_char(&up->port, ch))
continue;
if ((up->port.ignore_status_mask & AR933X_DUMMY_STATUS_RD) == 0)
tty_insert_flip_char(port, ch, TTY_NORMAL);
} while (max_count-- > 0);
tty: serial: ar933x: 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 14:44:08 +00:00
spin_unlock(&up->port.lock);
tty_flip_buffer_push(port);
tty: serial: ar933x: 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 14:44:08 +00:00
spin_lock(&up->port.lock);
}
static void ar933x_uart_tx_chars(struct ar933x_uart_port *up)
{
struct circ_buf *xmit = &up->port.state->xmit;
int count;
if (uart_tx_stopped(&up->port))
return;
count = up->port.fifosize;
do {
unsigned int rdata;
rdata = ar933x_uart_read(up, AR933X_UART_DATA_REG);
if ((rdata & AR933X_UART_DATA_TX_CSR) == 0)
break;
if (up->port.x_char) {
ar933x_uart_putc(up, up->port.x_char);
up->port.icount.tx++;
up->port.x_char = 0;
continue;
}
if (uart_circ_empty(xmit))
break;
ar933x_uart_putc(up, xmit->buf[xmit->tail]);
xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
up->port.icount.tx++;
} while (--count > 0);
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&up->port);
if (!uart_circ_empty(xmit))
ar933x_uart_start_tx_interrupt(up);
}
static irqreturn_t ar933x_uart_interrupt(int irq, void *dev_id)
{
struct ar933x_uart_port *up = dev_id;
unsigned int status;
status = ar933x_uart_read(up, AR933X_UART_CS_REG);
if ((status & AR933X_UART_CS_HOST_INT) == 0)
return IRQ_NONE;
spin_lock(&up->port.lock);
status = ar933x_uart_read(up, AR933X_UART_INT_REG);
status &= ar933x_uart_read(up, AR933X_UART_INT_EN_REG);
if (status & AR933X_UART_INT_RX_VALID) {
ar933x_uart_write(up, AR933X_UART_INT_REG,
AR933X_UART_INT_RX_VALID);
ar933x_uart_rx_chars(up);
}
if (status & AR933X_UART_INT_TX_EMPTY) {
ar933x_uart_write(up, AR933X_UART_INT_REG,
AR933X_UART_INT_TX_EMPTY);
ar933x_uart_stop_tx_interrupt(up);
ar933x_uart_tx_chars(up);
}
spin_unlock(&up->port.lock);
return IRQ_HANDLED;
}
static int ar933x_uart_startup(struct uart_port *port)
{
struct ar933x_uart_port *up =
container_of(port, struct ar933x_uart_port, port);
unsigned long flags;
int ret;
ret = request_irq(up->port.irq, ar933x_uart_interrupt,
up->port.irqflags, dev_name(up->port.dev), up);
if (ret)
return ret;
spin_lock_irqsave(&up->port.lock, flags);
/* Enable HOST interrupts */
ar933x_uart_rmw_set(up, AR933X_UART_CS_REG,
AR933X_UART_CS_HOST_INT_EN);
/* Enable RX interrupts */
up->ier = AR933X_UART_INT_RX_VALID;
ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
spin_unlock_irqrestore(&up->port.lock, flags);
return 0;
}
static void ar933x_uart_shutdown(struct uart_port *port)
{
struct ar933x_uart_port *up =
container_of(port, struct ar933x_uart_port, port);
/* Disable all interrupts */
up->ier = 0;
ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
/* Disable break condition */
ar933x_uart_rmw_clear(up, AR933X_UART_CS_REG,
AR933X_UART_CS_TX_BREAK);
free_irq(up->port.irq, up);
}
static const char *ar933x_uart_type(struct uart_port *port)
{
return (port->type == PORT_AR933X) ? "AR933X UART" : NULL;
}
static void ar933x_uart_release_port(struct uart_port *port)
{
/* Nothing to release ... */
}
static int ar933x_uart_request_port(struct uart_port *port)
{
/* UARTs always present */
return 0;
}
static void ar933x_uart_config_port(struct uart_port *port, int flags)
{
if (flags & UART_CONFIG_TYPE)
port->type = PORT_AR933X;
}
static int ar933x_uart_verify_port(struct uart_port *port,
struct serial_struct *ser)
{
struct ar933x_uart_port *up =
container_of(port, struct ar933x_uart_port, port);
tty/serial/ar933x_uart: fix baud rate calculation The UART of the AR933x SoC implements a fractional divisor for generating the desired baud rate. The current code uses a fixed value for the fractional part of the divisor, and this leads to improperly calculated baud rates: baud scale step real baud diff 300 5207* 8192 17756 17456 5818.66% 600 2603* 8192 35511 34911 5818.50% 1200 1301* 8192 71023 69823 5818.58% 2400 650* 8192 11241 8841 368.37% 4800 324* 8192 22645 17845 371.77% 9600 161 8192 9645 45 0.46% 14400 107 8192 14468 68 0.47% 19200 80 8192 19290 90 0.46% 28800 53 8192 28935 135 0.46% 38400 39 8192 39063 663 1.72% 57600 26 8192 57870 270 0.46% 115200 12 8192 120192 4992 4.33% 230400 5 8192 260417 30017 13.02% 460800 2 8192 520833 60033 13.02% 921600 0 8192 1562500 640900 69.93% After the patch, the integer and fractional parts of the divisor will be calculated dynamically. This ensures that the UART will use correct baud rates: baud scale step real baud diff 300 6 11 300 0 0.00% 600 54 173 600 0 0.00% 1200 30 195 1200 0 0.00% 2400 30 390 2400 0 0.00% 4800 48 1233 4800 0 0.00% 9600 78 3976 9600 0 0.00% 14400 98 7474 14400 0 0.00% 19200 55 5637 19200 0 0.00% 28800 130 19780 28800 0 0.00% 38400 36 7449 38400 0 0.00% 57600 78 23857 57600 0 0.00% 115200 43 26575 115200 0 0.00% 230400 23 28991 230400 0 0.00% 460800 11 28991 460800 0 0.00% 921600 5 28991 921599 -1 0.00% Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14 09:38:13 +00:00
if (ser->type != PORT_UNKNOWN &&
ser->type != PORT_AR933X)
return -EINVAL;
if (ser->irq < 0 || ser->irq >= NR_IRQS)
return -EINVAL;
tty/serial/ar933x_uart: fix baud rate calculation The UART of the AR933x SoC implements a fractional divisor for generating the desired baud rate. The current code uses a fixed value for the fractional part of the divisor, and this leads to improperly calculated baud rates: baud scale step real baud diff 300 5207* 8192 17756 17456 5818.66% 600 2603* 8192 35511 34911 5818.50% 1200 1301* 8192 71023 69823 5818.58% 2400 650* 8192 11241 8841 368.37% 4800 324* 8192 22645 17845 371.77% 9600 161 8192 9645 45 0.46% 14400 107 8192 14468 68 0.47% 19200 80 8192 19290 90 0.46% 28800 53 8192 28935 135 0.46% 38400 39 8192 39063 663 1.72% 57600 26 8192 57870 270 0.46% 115200 12 8192 120192 4992 4.33% 230400 5 8192 260417 30017 13.02% 460800 2 8192 520833 60033 13.02% 921600 0 8192 1562500 640900 69.93% After the patch, the integer and fractional parts of the divisor will be calculated dynamically. This ensures that the UART will use correct baud rates: baud scale step real baud diff 300 6 11 300 0 0.00% 600 54 173 600 0 0.00% 1200 30 195 1200 0 0.00% 2400 30 390 2400 0 0.00% 4800 48 1233 4800 0 0.00% 9600 78 3976 9600 0 0.00% 14400 98 7474 14400 0 0.00% 19200 55 5637 19200 0 0.00% 28800 130 19780 28800 0 0.00% 38400 36 7449 38400 0 0.00% 57600 78 23857 57600 0 0.00% 115200 43 26575 115200 0 0.00% 230400 23 28991 230400 0 0.00% 460800 11 28991 460800 0 0.00% 921600 5 28991 921599 -1 0.00% Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14 09:38:13 +00:00
if (ser->baud_base < up->min_baud ||
ser->baud_base > up->max_baud)
return -EINVAL;
return 0;
}
tty: serial: constify uart_ops structures Declare uart_ops structures as const as they are only stored in the ops field of an uart_port structure. This field is of type const, so uart_ops structures having this property can be made const too. File size details before and after patching. First line of every .o file shows the file size before patching and second line shows the size after patching. text data bss dec hex filename 2977 456 64 3497 da9 drivers/tty/serial/amba-pl010.o 3169 272 64 3505 db1 drivers/tty/serial/amba-pl010.o 3109 456 0 3565 ded drivers/tty/serial/efm32-uart.o 3301 272 0 3573 df5 drivers/tty/serial/efm32-uart.o 10668 753 1 11422 2c9e drivers/tty/serial/icom.o 10860 561 1 11422 2c9e drivers/tty/serial/icom.o 23904 408 8 24320 5f00 drivers/tty/serial/ioc3_serial.o 24088 224 8 24320 5f00 drivers/tty/serial/ioc3_serial.o 10516 560 4 11080 2b48 drivers/tty/serial/ioc4_serial.o 10709 368 4 11081 2b49 drivers/tty/serial/ioc4_serial.o 7853 648 1216 9717 25f5 drivers/tty/serial/mpsc.o 8037 456 1216 9709 25ed drivers/tty/serial/mpsc.o 10248 456 0 10704 29d0 drivers/tty/serial/omap-serial.o 10440 272 0 10712 29d8 drivers/tty/serial/omap-serial.o 8122 532 1984 10638 298e drivers/tty/serial/pmac_zilog.o 8306 340 1984 10630 2986 drivers/tty/serial/pmac_zilog.o 3808 456 0 4264 10a8 drivers/tty/serial/pxa.o 4000 264 0 4264 10a8 drivers/tty/serial/pxa.o 21781 3864 0 25645 642d drivers/tty/serial/serial-tegra.o 22037 3608 0 25645 642d drivers/tty/serial/serial-tegra.o 2481 456 96 3033 bd9 drivers/tty/serial/sprd_serial.o 2673 272 96 3041 be1 drivers/tty/serial/sprd_serial.o 5534 300 512 6346 18ca drivers/tty/serial/vr41xx_siu.o 5630 204 512 6346 18ca drivers/tty/serial/vr41xx_siu.o 6730 1576 128 8434 20f2 drivers/tty/serial/vt8500_serial.o 6986 1320 128 8434 20f2 drivers/tty/serial/vt8500_serial.o Cross compiled for mips architecture. 3005 488 0 3493 da5 drivers/tty/serial/pnx8xxx_uart.o 3189 304 0 3493 da5 drivers/tty/serial/pnx8xxx_uart.o 4272 196 1056 5524 1594 drivers/tty/serial/dz.o 4368 100 1056 5524 1594 drivers/tty/serial/dz.o 6551 144 16 6711 1a37 drivers/tty/serial/ip22zilog.o 6647 48 16 6711 1a37 drivers/tty/serial/ip22zilog.o 9612 428 1520 11560 2d28 drivers/tty/serial/serial_txx9.o 9708 332 1520 11560 2d28 drivers/tty/serial/serial_txx9.o 4156 296 16 4468 1174 drivers/tty/serial/ar933x_uart.o 4252 200 16 4468 1174 drivers/tty/serial/ar933x_uart.o Cross compiled for arm archiecture. 11716 1780 44 13540 34e4 drivers/tty/serial/sirfsoc_uart.o 11808 1688 44 13540 34e4 drivers/tty/serial/sirfsoc_uart.o 13352 596 56 14004 36b4 drivers/tty/serial/amba-pl011.o 13444 504 56 14004 36b4 drivers/tty/serial/amba-pl011.o Cross compiled for sparc architecture. 4664 528 32 5224 1468 drivers/tty/serial/sunhv.o 4848 344 32 5224 1468 drivers/tty/serial/sunhv.o 8080 332 28 8440 20f8 drivers/tty/serial/sunzilog.o 8184 228 28 8440 20f8 drivers/tty/serial/sunzilog.o Cross compiled for ia64 architecture. 10226 549 472 11247 2bef drivers/tty/serial/sn_console.o 10414 365 472 11251 2bf3 drivers/tty/serial/sn_console.o The files drivers/tty/serial/zs.o, drivers/tty/serial/lpc32xx_hs.o and drivers/tty/serial/lantiq.o did not compile. Signed-off-by: Bhumika Goyal <bhumirks@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-25 17:48:52 +00:00
static const struct uart_ops ar933x_uart_ops = {
.tx_empty = ar933x_uart_tx_empty,
.set_mctrl = ar933x_uart_set_mctrl,
.get_mctrl = ar933x_uart_get_mctrl,
.stop_tx = ar933x_uart_stop_tx,
.start_tx = ar933x_uart_start_tx,
.stop_rx = ar933x_uart_stop_rx,
.break_ctl = ar933x_uart_break_ctl,
.startup = ar933x_uart_startup,
.shutdown = ar933x_uart_shutdown,
.set_termios = ar933x_uart_set_termios,
.type = ar933x_uart_type,
.release_port = ar933x_uart_release_port,
.request_port = ar933x_uart_request_port,
.config_port = ar933x_uart_config_port,
.verify_port = ar933x_uart_verify_port,
};
static struct ar933x_uart_port *
ar933x_console_ports[CONFIG_SERIAL_AR933X_NR_UARTS];
static void ar933x_uart_wait_xmitr(struct ar933x_uart_port *up)
{
unsigned int status;
unsigned int timeout = 60000;
/* Wait up to 60ms for the character(s) to be sent. */
do {
status = ar933x_uart_read(up, AR933X_UART_DATA_REG);
if (--timeout == 0)
break;
udelay(1);
} while ((status & AR933X_UART_DATA_TX_CSR) == 0);
}
static void ar933x_uart_console_putchar(struct uart_port *port, int ch)
{
struct ar933x_uart_port *up =
container_of(port, struct ar933x_uart_port, port);
ar933x_uart_wait_xmitr(up);
ar933x_uart_putc(up, ch);
}
static void ar933x_uart_console_write(struct console *co, const char *s,
unsigned int count)
{
struct ar933x_uart_port *up = ar933x_console_ports[co->index];
unsigned long flags;
unsigned int int_en;
int locked = 1;
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);
/*
* First save the IER then disable the interrupts
*/
int_en = ar933x_uart_read(up, AR933X_UART_INT_EN_REG);
ar933x_uart_write(up, AR933X_UART_INT_EN_REG, 0);
uart_console_write(&up->port, s, count, ar933x_uart_console_putchar);
/*
* Finally, wait for transmitter to become empty
* and restore the IER
*/
ar933x_uart_wait_xmitr(up);
ar933x_uart_write(up, AR933X_UART_INT_EN_REG, int_en);
ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_ALLINTS);
if (locked)
spin_unlock(&up->port.lock);
local_irq_restore(flags);
}
static int ar933x_uart_console_setup(struct console *co, char *options)
{
struct ar933x_uart_port *up;
int baud = 115200;
int bits = 8;
int parity = 'n';
int flow = 'n';
if (co->index < 0 || co->index >= CONFIG_SERIAL_AR933X_NR_UARTS)
return -EINVAL;
up = ar933x_console_ports[co->index];
if (!up)
return -ENODEV;
if (options)
uart_parse_options(options, &baud, &parity, &bits, &flow);
return uart_set_options(&up->port, co, baud, parity, bits, flow);
}
static struct console ar933x_uart_console = {
.name = "ttyATH",
.write = ar933x_uart_console_write,
.device = uart_console_device,
.setup = ar933x_uart_console_setup,
.flags = CON_PRINTBUFFER,
.index = -1,
.data = &ar933x_uart_driver,
};
static void ar933x_uart_add_console_port(struct ar933x_uart_port *up)
{
if (!ar933x_uart_console_enabled())
return;
ar933x_console_ports[up->port.line] = up;
}
static struct uart_driver ar933x_uart_driver = {
.owner = THIS_MODULE,
.driver_name = DRIVER_NAME,
.dev_name = "ttyATH",
.nr = CONFIG_SERIAL_AR933X_NR_UARTS,
.cons = NULL, /* filled in runtime */
};
static int ar933x_uart_probe(struct platform_device *pdev)
{
struct ar933x_uart_port *up;
struct uart_port *port;
struct resource *mem_res;
struct resource *irq_res;
struct device_node *np;
tty/serial/ar933x_uart: fix baud rate calculation The UART of the AR933x SoC implements a fractional divisor for generating the desired baud rate. The current code uses a fixed value for the fractional part of the divisor, and this leads to improperly calculated baud rates: baud scale step real baud diff 300 5207* 8192 17756 17456 5818.66% 600 2603* 8192 35511 34911 5818.50% 1200 1301* 8192 71023 69823 5818.58% 2400 650* 8192 11241 8841 368.37% 4800 324* 8192 22645 17845 371.77% 9600 161 8192 9645 45 0.46% 14400 107 8192 14468 68 0.47% 19200 80 8192 19290 90 0.46% 28800 53 8192 28935 135 0.46% 38400 39 8192 39063 663 1.72% 57600 26 8192 57870 270 0.46% 115200 12 8192 120192 4992 4.33% 230400 5 8192 260417 30017 13.02% 460800 2 8192 520833 60033 13.02% 921600 0 8192 1562500 640900 69.93% After the patch, the integer and fractional parts of the divisor will be calculated dynamically. This ensures that the UART will use correct baud rates: baud scale step real baud diff 300 6 11 300 0 0.00% 600 54 173 600 0 0.00% 1200 30 195 1200 0 0.00% 2400 30 390 2400 0 0.00% 4800 48 1233 4800 0 0.00% 9600 78 3976 9600 0 0.00% 14400 98 7474 14400 0 0.00% 19200 55 5637 19200 0 0.00% 28800 130 19780 28800 0 0.00% 38400 36 7449 38400 0 0.00% 57600 78 23857 57600 0 0.00% 115200 43 26575 115200 0 0.00% 230400 23 28991 230400 0 0.00% 460800 11 28991 460800 0 0.00% 921600 5 28991 921599 -1 0.00% Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14 09:38:13 +00:00
unsigned int baud;
int id;
int ret;
np = pdev->dev.of_node;
tree-wide: replace config_enabled() with IS_ENABLED() The use of config_enabled() against config options is ambiguous. In practical terms, config_enabled() is equivalent to IS_BUILTIN(), but the author might have used it for the meaning of IS_ENABLED(). Using IS_ENABLED(), IS_BUILTIN(), IS_MODULE() etc. makes the intention clearer. This commit replaces config_enabled() with IS_ENABLED() where possible. This commit is only touching bool config options. I noticed two cases where config_enabled() is used against a tristate option: - config_enabled(CONFIG_HWMON) [ drivers/net/wireless/ath/ath10k/thermal.c ] - config_enabled(CONFIG_BACKLIGHT_CLASS_DEVICE) [ drivers/gpu/drm/gma500/opregion.c ] I did not touch them because they should be converted to IS_BUILTIN() in order to keep the logic, but I was not sure it was the authors' intention. Link: http://lkml.kernel.org/r/1465215656-20569-1-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Stas Sergeev <stsp@list.ru> Cc: Matt Redfearn <matt.redfearn@imgtec.com> Cc: Joshua Kinard <kumba@gentoo.org> Cc: Jiri Slaby <jslaby@suse.com> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Borislav Petkov <bp@suse.de> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: "Dmitry V. Levin" <ldv@altlinux.org> Cc: yu-cheng yu <yu-cheng.yu@intel.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Brian Gerst <brgerst@gmail.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Will Drewry <wad@chromium.org> Cc: Nikolay Martynov <mar.kolya@gmail.com> Cc: Huacai Chen <chenhc@lemote.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Leonid Yegoshin <Leonid.Yegoshin@imgtec.com> Cc: Rafal Milecki <zajec5@gmail.com> Cc: James Cowgill <James.Cowgill@imgtec.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Alex Smith <alex.smith@imgtec.com> Cc: Adam Buchbinder <adam.buchbinder@gmail.com> Cc: Qais Yousef <qais.yousef@imgtec.com> Cc: Jiang Liu <jiang.liu@linux.intel.com> Cc: Mikko Rapeli <mikko.rapeli@iki.fi> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: Brian Norris <computersforpeace@gmail.com> Cc: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Cc: "Luis R. Rodriguez" <mcgrof@do-not-panic.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ingo Molnar <mingo@redhat.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Roland McGrath <roland@hack.frob.com> Cc: Paul Burton <paul.burton@imgtec.com> Cc: Kalle Valo <kvalo@qca.qualcomm.com> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Tony Wu <tung7970@gmail.com> Cc: Huaitong Han <huaitong.han@intel.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Juergen Gross <jgross@suse.com> Cc: Jason Cooper <jason@lakedaemon.net> Cc: "David S. Miller" <davem@davemloft.net> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Andrea Gelmini <andrea.gelmini@gelma.net> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Rabin Vincent <rabin@rab.in> Cc: "Maciej W. Rozycki" <macro@imgtec.com> Cc: David Daney <david.daney@cavium.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-03 20:45:50 +00:00
if (IS_ENABLED(CONFIG_OF) && np) {
id = of_alias_get_id(np, "serial");
if (id < 0) {
dev_err(&pdev->dev, "unable to get alias id, err=%d\n",
id);
return id;
}
} else {
id = pdev->id;
if (id == -1)
id = 0;
}
if (id >= CONFIG_SERIAL_AR933X_NR_UARTS)
return -EINVAL;
irq_res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!irq_res) {
dev_err(&pdev->dev, "no IRQ resource\n");
return -EINVAL;
}
up = devm_kzalloc(&pdev->dev, sizeof(struct ar933x_uart_port),
GFP_KERNEL);
if (!up)
return -ENOMEM;
up->clk = devm_clk_get(&pdev->dev, "uart");
if (IS_ERR(up->clk)) {
dev_err(&pdev->dev, "unable to get UART clock\n");
return PTR_ERR(up->clk);
}
port = &up->port;
mem_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
port->membase = devm_ioremap_resource(&pdev->dev, mem_res);
if (IS_ERR(port->membase))
return PTR_ERR(port->membase);
ret = clk_prepare_enable(up->clk);
if (ret)
return ret;
port->uartclk = clk_get_rate(up->clk);
if (!port->uartclk) {
ret = -EINVAL;
goto err_disable_clk;
}
port->mapbase = mem_res->start;
port->line = id;
port->irq = irq_res->start;
port->dev = &pdev->dev;
port->type = PORT_AR933X;
port->iotype = UPIO_MEM32;
port->regshift = 2;
port->fifosize = AR933X_UART_FIFO_SIZE;
port->ops = &ar933x_uart_ops;
tty/serial/ar933x_uart: fix baud rate calculation The UART of the AR933x SoC implements a fractional divisor for generating the desired baud rate. The current code uses a fixed value for the fractional part of the divisor, and this leads to improperly calculated baud rates: baud scale step real baud diff 300 5207* 8192 17756 17456 5818.66% 600 2603* 8192 35511 34911 5818.50% 1200 1301* 8192 71023 69823 5818.58% 2400 650* 8192 11241 8841 368.37% 4800 324* 8192 22645 17845 371.77% 9600 161 8192 9645 45 0.46% 14400 107 8192 14468 68 0.47% 19200 80 8192 19290 90 0.46% 28800 53 8192 28935 135 0.46% 38400 39 8192 39063 663 1.72% 57600 26 8192 57870 270 0.46% 115200 12 8192 120192 4992 4.33% 230400 5 8192 260417 30017 13.02% 460800 2 8192 520833 60033 13.02% 921600 0 8192 1562500 640900 69.93% After the patch, the integer and fractional parts of the divisor will be calculated dynamically. This ensures that the UART will use correct baud rates: baud scale step real baud diff 300 6 11 300 0 0.00% 600 54 173 600 0 0.00% 1200 30 195 1200 0 0.00% 2400 30 390 2400 0 0.00% 4800 48 1233 4800 0 0.00% 9600 78 3976 9600 0 0.00% 14400 98 7474 14400 0 0.00% 19200 55 5637 19200 0 0.00% 28800 130 19780 28800 0 0.00% 38400 36 7449 38400 0 0.00% 57600 78 23857 57600 0 0.00% 115200 43 26575 115200 0 0.00% 230400 23 28991 230400 0 0.00% 460800 11 28991 460800 0 0.00% 921600 5 28991 921599 -1 0.00% Signed-off-by: Gabor Juhos <juhosg@openwrt.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-11-14 09:38:13 +00:00
baud = ar933x_uart_get_baud(port->uartclk, AR933X_UART_MAX_SCALE, 1);
up->min_baud = max_t(unsigned int, baud, AR933X_UART_MIN_BAUD);
baud = ar933x_uart_get_baud(port->uartclk, 0, AR933X_UART_MAX_STEP);
up->max_baud = min_t(unsigned int, baud, AR933X_UART_MAX_BAUD);
ar933x_uart_add_console_port(up);
ret = uart_add_one_port(&ar933x_uart_driver, &up->port);
if (ret)
goto err_disable_clk;
platform_set_drvdata(pdev, up);
return 0;
err_disable_clk:
clk_disable_unprepare(up->clk);
return ret;
}
static int ar933x_uart_remove(struct platform_device *pdev)
{
struct ar933x_uart_port *up;
up = platform_get_drvdata(pdev);
if (up) {
uart_remove_one_port(&ar933x_uart_driver, &up->port);
clk_disable_unprepare(up->clk);
}
return 0;
}
#ifdef CONFIG_OF
static const struct of_device_id ar933x_uart_of_ids[] = {
{ .compatible = "qca,ar9330-uart" },
{},
};
MODULE_DEVICE_TABLE(of, ar933x_uart_of_ids);
#endif
static struct platform_driver ar933x_uart_platform_driver = {
.probe = ar933x_uart_probe,
.remove = ar933x_uart_remove,
.driver = {
.name = DRIVER_NAME,
.of_match_table = of_match_ptr(ar933x_uart_of_ids),
},
};
static int __init ar933x_uart_init(void)
{
int ret;
if (ar933x_uart_console_enabled())
ar933x_uart_driver.cons = &ar933x_uart_console;
ret = uart_register_driver(&ar933x_uart_driver);
if (ret)
goto err_out;
ret = platform_driver_register(&ar933x_uart_platform_driver);
if (ret)
goto err_unregister_uart_driver;
return 0;
err_unregister_uart_driver:
uart_unregister_driver(&ar933x_uart_driver);
err_out:
return ret;
}
static void __exit ar933x_uart_exit(void)
{
platform_driver_unregister(&ar933x_uart_platform_driver);
uart_unregister_driver(&ar933x_uart_driver);
}
module_init(ar933x_uart_init);
module_exit(ar933x_uart_exit);
MODULE_DESCRIPTION("Atheros AR933X UART driver");
MODULE_AUTHOR("Gabor Juhos <juhosg@openwrt.org>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:" DRIVER_NAME);