linux_dsm_epyc7002/drivers/tty/serial/8250/8250.h

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/*
* Driver for 8250/16550-type serial ports
*
* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
*
* Copyright (C) 2001 Russell King.
*
* 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.
*/
#include <linux/serial_8250.h>
serial/uart/8250: Add tunable RX interrupt trigger I/F of FIFO buffers Add tunable RX interrupt trigger I/F of FIFO buffers. Serial devices are used as not only message communication devices but control or sending communication devices. For the latter uses, normally small data will be exchanged, so user applications want to receive data unit as soon as possible for real-time tendency. If we have a sensor which sends a 1 byte data each time and must control a device based on the sensor feedback, the RX interrupt should be triggered for each data. According to HW specification of serial UART devices, RX interrupt trigger can be changed, but the trigger is hard-coded. For example, RX interrupt trigger in 16550A can be set to 1, 4, 8, or 14 bytes for HW, but current driver sets the trigger to only 8bytes. This patch makes some devices change RX interrupt trigger from userland. <How to use> - Read current setting # cat /sys/class/tty/ttyS0/rx_trig_bytes 8 - Write user setting # echo 1 > /sys/class/tty/ttyS0/rx_trig_bytes # cat /sys/class/tty/ttyS0/rx_trig_bytes 1 <Support uart devices> - 16550A and Tegra (1, 4, 8, or 14 bytes) - 16650V2 (8, 16, 24, or 28 bytes) - 16654 (8, 16, 56, or 60 bytes) - 16750 (1, 16, 32, or 56 bytes) <Change log> Changes in V9: - Use attr_group instead of dev_spec_attr_group of uart_port structure Changes in V8: - Divide this patch from V7's patch based on Greg's comment Changes in V7: - Add Documentation - Change I/F name from rx_int_trig to rx_trig_bytes because the name rx_int_trig is hard to understand how users specify the value Changes in V6: - Move FCR_RX_TRIG_* definition in 8250.h to include/uapi/linux/serial_reg.h, rename those to UART_FCR_R_TRIG_*, and use UART_FCR_TRIGGER_MASK to UART_FCR_R_TRIG_BITS() - Change following function names: convert_fcr2val() => fcr_get_rxtrig_bytes() convert_val2rxtrig() => bytes_to_fcr_rxtrig() - Fix typo in serial8250_do_set_termios() - Delete the verbose error message pr_info() in bytes_to_fcr_rxtrig() - Rename *rx_int_trig/rx_trig* to *rxtrig* for several functions or variables (but UI remains rx_int_trig) - Change the meaningless variable name 'val' to 'bytes' following functions: fcr_get_rxtrig_bytes(), bytes_to_fcr_rxtrig(), do_set_rxtrig(), do_serial8250_set_rxtrig(), and serial8250_set_attr_rxtrig() - Use up->fcr in order to get rxtrig_bytes instead of rx_trig_raw in fcr_get_rxtrig_bytes() - Use conf_type->rxtrig_bytes[0] instead of switch statement for support check in register_dev_spec_attr_grp() - Delete the checking whether a user changed FCR or not when minimum buffer is needed in serial8250_do_set_termios() Changes in V5.1: - Fix FCR_RX_TRIG_MAX_STATE definition Changes in V5: - Support Tegra, 16650V2, 16654, and 16750 - Store default FCR value to up->fcr when the port is first created - Add rx_trig_byte[] in uart_config[] for each device and use rx_trig_byte[] in convert_fcr2val() and convert_val2rxtrig() Changes in V4: - Introduce fifo_bug flag in uart_8250_port structure This is enabled only when parity is enabled and UART_BUG_PARITY is enabled for up->bugs. If this flag is enabled, user cannot set RX trigger. - Return -EOPNOTSUPP when it does not support device at convert_fcr2val() and at convert_val2rxtrig() - Set the nearest lower RX trigger when users input a meaningless value at convert_val2rxtrig() - Check whether p->fcr is existing at serial8250_clear_and_reinit_fifos() - Set fcr = up->fcr in the begging of serial8250_do_set_termios() Changes in V3: - Change I/F from ioctl(2) to sysfs(rx_int_trig) Changed in V2: - Use _IOW for TIOCSFIFORTRIG definition - Pass the interrupt trigger value itself Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-16 08:19:36 +07:00
#include <linux/serial_reg.h>
#include <linux/dmaengine.h>
struct uart_8250_dma {
int (*tx_dma)(struct uart_8250_port *p);
int (*rx_dma)(struct uart_8250_port *p, unsigned int iir);
/* Filter function */
dma_filter_fn fn;
/* Parameter to the filter function */
void *rx_param;
void *tx_param;
struct dma_slave_config rxconf;
struct dma_slave_config txconf;
struct dma_chan *rxchan;
struct dma_chan *txchan;
dma_addr_t rx_addr;
dma_addr_t tx_addr;
dma_cookie_t rx_cookie;
dma_cookie_t tx_cookie;
void *rx_buf;
size_t rx_size;
size_t tx_size;
unsigned char tx_running;
unsigned char tx_err;
unsigned char rx_running;
};
struct old_serial_port {
unsigned int uart;
unsigned int baud_base;
unsigned int port;
unsigned int irq;
upf_t flags;
unsigned char hub6;
unsigned char io_type;
unsigned char __iomem *iomem_base;
unsigned short iomem_reg_shift;
unsigned long irqflags;
};
struct serial8250_config {
const char *name;
unsigned short fifo_size;
unsigned short tx_loadsz;
unsigned char fcr;
serial/uart/8250: Add tunable RX interrupt trigger I/F of FIFO buffers Add tunable RX interrupt trigger I/F of FIFO buffers. Serial devices are used as not only message communication devices but control or sending communication devices. For the latter uses, normally small data will be exchanged, so user applications want to receive data unit as soon as possible for real-time tendency. If we have a sensor which sends a 1 byte data each time and must control a device based on the sensor feedback, the RX interrupt should be triggered for each data. According to HW specification of serial UART devices, RX interrupt trigger can be changed, but the trigger is hard-coded. For example, RX interrupt trigger in 16550A can be set to 1, 4, 8, or 14 bytes for HW, but current driver sets the trigger to only 8bytes. This patch makes some devices change RX interrupt trigger from userland. <How to use> - Read current setting # cat /sys/class/tty/ttyS0/rx_trig_bytes 8 - Write user setting # echo 1 > /sys/class/tty/ttyS0/rx_trig_bytes # cat /sys/class/tty/ttyS0/rx_trig_bytes 1 <Support uart devices> - 16550A and Tegra (1, 4, 8, or 14 bytes) - 16650V2 (8, 16, 24, or 28 bytes) - 16654 (8, 16, 56, or 60 bytes) - 16750 (1, 16, 32, or 56 bytes) <Change log> Changes in V9: - Use attr_group instead of dev_spec_attr_group of uart_port structure Changes in V8: - Divide this patch from V7's patch based on Greg's comment Changes in V7: - Add Documentation - Change I/F name from rx_int_trig to rx_trig_bytes because the name rx_int_trig is hard to understand how users specify the value Changes in V6: - Move FCR_RX_TRIG_* definition in 8250.h to include/uapi/linux/serial_reg.h, rename those to UART_FCR_R_TRIG_*, and use UART_FCR_TRIGGER_MASK to UART_FCR_R_TRIG_BITS() - Change following function names: convert_fcr2val() => fcr_get_rxtrig_bytes() convert_val2rxtrig() => bytes_to_fcr_rxtrig() - Fix typo in serial8250_do_set_termios() - Delete the verbose error message pr_info() in bytes_to_fcr_rxtrig() - Rename *rx_int_trig/rx_trig* to *rxtrig* for several functions or variables (but UI remains rx_int_trig) - Change the meaningless variable name 'val' to 'bytes' following functions: fcr_get_rxtrig_bytes(), bytes_to_fcr_rxtrig(), do_set_rxtrig(), do_serial8250_set_rxtrig(), and serial8250_set_attr_rxtrig() - Use up->fcr in order to get rxtrig_bytes instead of rx_trig_raw in fcr_get_rxtrig_bytes() - Use conf_type->rxtrig_bytes[0] instead of switch statement for support check in register_dev_spec_attr_grp() - Delete the checking whether a user changed FCR or not when minimum buffer is needed in serial8250_do_set_termios() Changes in V5.1: - Fix FCR_RX_TRIG_MAX_STATE definition Changes in V5: - Support Tegra, 16650V2, 16654, and 16750 - Store default FCR value to up->fcr when the port is first created - Add rx_trig_byte[] in uart_config[] for each device and use rx_trig_byte[] in convert_fcr2val() and convert_val2rxtrig() Changes in V4: - Introduce fifo_bug flag in uart_8250_port structure This is enabled only when parity is enabled and UART_BUG_PARITY is enabled for up->bugs. If this flag is enabled, user cannot set RX trigger. - Return -EOPNOTSUPP when it does not support device at convert_fcr2val() and at convert_val2rxtrig() - Set the nearest lower RX trigger when users input a meaningless value at convert_val2rxtrig() - Check whether p->fcr is existing at serial8250_clear_and_reinit_fifos() - Set fcr = up->fcr in the begging of serial8250_do_set_termios() Changes in V3: - Change I/F from ioctl(2) to sysfs(rx_int_trig) Changed in V2: - Use _IOW for TIOCSFIFORTRIG definition - Pass the interrupt trigger value itself Signed-off-by: Yoshihiro YUNOMAE <yoshihiro.yunomae.ez@hitachi.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-07-16 08:19:36 +07:00
unsigned char rxtrig_bytes[UART_FCR_R_TRIG_MAX_STATE];
unsigned int flags;
};
#define UART_CAP_FIFO (1 << 8) /* UART has FIFO */
#define UART_CAP_EFR (1 << 9) /* UART has EFR */
#define UART_CAP_SLEEP (1 << 10) /* UART has IER sleep */
#define UART_CAP_AFE (1 << 11) /* MCR-based hw flow control */
#define UART_CAP_UUE (1 << 12) /* UART needs IER bit 6 set (Xscale) */
#define UART_CAP_RTOIE (1 << 13) /* UART needs IER bit 4 set (Xscale, Tegra) */
#define UART_CAP_HFIFO (1 << 14) /* UART has a "hidden" FIFO */
tty: serial: 8250_core: add run time pm While comparing the OMAP-serial and the 8250 part of this I noticed that the latter does not use run time-pm. Here are the pieces. It is basically a get before first register access and a last_busy + put after last access. This has to be enabled from userland _and_ UART_CAP_RPM is required for this. The runtime PM can usually work transparently in the background however there is one exception to this: After serial8250_tx_chars() completes there still may be unsent bytes in the FIFO (depending on CPU speed vs baud rate + flow control). Even if the TTY-buffer is empty we do not want RPM to disable the device because it won't send the remaining bytes. Instead we leave serial8250_tx_chars() with RPM enabled and wait for the FIFO empty interrupt. Once we enter serial8250_tx_chars() with an empty buffer we know that the FIFO is empty and since we are not going to send anything, we can disable the device. That xchg() is to ensure that serial8250_tx_chars() can be called multiple times and only the first invocation will actually invoke the runtime PM function. So that the last invocation of __stop_tx() will disable runtime pm. NOTE: do not enable RPM on the device unless you know what you do! If the device goes idle, it won't be woken up by incomming RX data _unless_ there is a wakeup irq configured which is usually the RX pin configure for wakeup via the reset module. The RX activity will then wake up the device from idle. However the first character is garbage and lost. The following bytes will be received once the device is up in time. On the beagle board xm (omap3) it takes approx 13ms from the first wakeup byte until the first byte that is received properly if the device was in core-off. v5…v8: - drop RPM from serial8250_set_mctrl() it will be used in restore path which already has RPM active and holds dev->power.lock v4…v5: - add a wrapper around rpm function and introduce UART_CAP_RPM to ensure RPM put is invoked after the TX FIFO is empty. v3…v4: - added runtime to the console code - removed device_may_wakeup() from serial8250_set_sleep() Cc: mika.westerberg@linux.intel.com Reviewed-by: Tony Lindgren <tony@atomide.com> Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-09-11 02:29:57 +07:00
#define UART_CAP_RPM (1 << 15) /* Runtime PM is active while idle */
#define UART_BUG_QUOT (1 << 0) /* UART has buggy quot LSB */
#define UART_BUG_TXEN (1 << 1) /* UART has buggy TX IIR status */
#define UART_BUG_NOMSR (1 << 2) /* UART has buggy MSR status bits (Au1x00) */
#define UART_BUG_THRE (1 << 3) /* UART has buggy THRE reassertion */
#define UART_BUG_PARITY (1 << 4) /* UART mishandles parity if FIFO enabled */
#define HIGH_BITS_OFFSET ((sizeof(long)-sizeof(int))*8)
#ifdef CONFIG_SERIAL_8250_SHARE_IRQ
#define SERIAL8250_SHARE_IRQS 1
#else
#define SERIAL8250_SHARE_IRQS 0
#endif
static inline int serial_in(struct uart_8250_port *up, int offset)
{
return up->port.serial_in(&up->port, offset);
}
static inline void serial_out(struct uart_8250_port *up, int offset, int value)
{
up->port.serial_out(&up->port, offset, value);
}
void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p);
static inline int serial_dl_read(struct uart_8250_port *up)
{
return up->dl_read(up);
}
static inline void serial_dl_write(struct uart_8250_port *up, int value)
{
up->dl_write(up, value);
}
struct uart_8250_port *serial8250_get_port(int line);
void serial8250_rpm_get(struct uart_8250_port *p);
void serial8250_rpm_put(struct uart_8250_port *p);
int serial8250_em485_init(struct uart_8250_port *p);
void serial8250_em485_destroy(struct uart_8250_port *p);
#if defined(__alpha__) && !defined(CONFIG_PCI)
/*
* Digital did something really horribly wrong with the OUT1 and OUT2
* lines on at least some ALPHA's. The failure mode is that if either
* is cleared, the machine locks up with endless interrupts.
*/
#define ALPHA_KLUDGE_MCR (UART_MCR_OUT2 | UART_MCR_OUT1)
#else
#define ALPHA_KLUDGE_MCR 0
#endif
#ifdef CONFIG_SERIAL_8250_PNP
int serial8250_pnp_init(void);
void serial8250_pnp_exit(void);
#else
static inline int serial8250_pnp_init(void) { return 0; }
static inline void serial8250_pnp_exit(void) { }
#endif
#ifdef CONFIG_ARCH_OMAP1
static inline int is_omap1_8250(struct uart_8250_port *pt)
{
int res;
switch (pt->port.mapbase) {
case OMAP1_UART1_BASE:
case OMAP1_UART2_BASE:
case OMAP1_UART3_BASE:
res = 1;
break;
default:
res = 0;
break;
}
return res;
}
static inline int is_omap1510_8250(struct uart_8250_port *pt)
{
if (!cpu_is_omap1510())
return 0;
return is_omap1_8250(pt);
}
#else
static inline int is_omap1_8250(struct uart_8250_port *pt)
{
return 0;
}
static inline int is_omap1510_8250(struct uart_8250_port *pt)
{
return 0;
}
#endif
#ifdef CONFIG_SERIAL_8250_DMA
extern int serial8250_tx_dma(struct uart_8250_port *);
extern int serial8250_rx_dma(struct uart_8250_port *, unsigned int iir);
extern int serial8250_request_dma(struct uart_8250_port *);
extern void serial8250_release_dma(struct uart_8250_port *);
#else
static inline int serial8250_tx_dma(struct uart_8250_port *p)
{
return -1;
}
static inline int serial8250_rx_dma(struct uart_8250_port *p, unsigned int iir)
{
return -1;
}
static inline int serial8250_request_dma(struct uart_8250_port *p)
{
return -1;
}
static inline void serial8250_release_dma(struct uart_8250_port *p) { }
#endif
static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
{
unsigned char status;
status = serial_in(up, 0x04); /* EXCR2 */
#define PRESL(x) ((x) & 0x30)
if (PRESL(status) == 0x10) {
/* already in high speed mode */
return 0;
} else {
status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
status |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
serial_out(up, 0x04, status);
}
return 1;
}
static inline int serial_index(struct uart_port *port)
{
return port->minor - 64;
}
#if 0
#define DEBUG_INTR(fmt...) printk(fmt)
#else
#define DEBUG_INTR(fmt...) do { } while (0)
#endif