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d087e7a991
The AUX/mini-UART in the BCM2835 family of procesors is a cut-down 8250 clone. In particular it is lacking support for the following features: CSTOPB PARENB PARODD CMSPAR CS5 CS6 Add a new capability (UART_CAP_MINI) that exposes the restrictions to the user of the termios API by turning off the unsupported features in the request. N.B. It is almost possible to automatically discover the missing features by reading back the LCR register, but the CSIZE bits don't cooperate (contrary to the documentation, both bits are significant, but CS5 and CS6 are mapped to CS7) and the code is much longer. See: https://github.com/raspberrypi/linux/issues/1561 Signed-off-by: Phil Elwell <phil@raspberrypi.org> Acked-by: Eric Anholt <eric@anholt.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
262 lines
6.6 KiB
C
262 lines
6.6 KiB
C
/*
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* Driver for 8250/16550-type serial ports
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*
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* Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
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*
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* Copyright (C) 2001 Russell King.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*/
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#include <linux/serial_8250.h>
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#include <linux/serial_reg.h>
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#include <linux/dmaengine.h>
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struct uart_8250_dma {
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int (*tx_dma)(struct uart_8250_port *p);
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int (*rx_dma)(struct uart_8250_port *p);
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/* Filter function */
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dma_filter_fn fn;
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/* Parameter to the filter function */
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void *rx_param;
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void *tx_param;
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struct dma_slave_config rxconf;
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struct dma_slave_config txconf;
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struct dma_chan *rxchan;
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struct dma_chan *txchan;
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/* Device address base for DMA operations */
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phys_addr_t rx_dma_addr;
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phys_addr_t tx_dma_addr;
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/* DMA address of the buffer in memory */
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dma_addr_t rx_addr;
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dma_addr_t tx_addr;
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dma_cookie_t rx_cookie;
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dma_cookie_t tx_cookie;
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void *rx_buf;
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size_t rx_size;
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size_t tx_size;
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unsigned char tx_running;
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unsigned char tx_err;
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unsigned char rx_running;
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};
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struct old_serial_port {
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unsigned int uart;
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unsigned int baud_base;
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unsigned int port;
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unsigned int irq;
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upf_t flags;
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unsigned char io_type;
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unsigned char __iomem *iomem_base;
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unsigned short iomem_reg_shift;
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};
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struct serial8250_config {
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const char *name;
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unsigned short fifo_size;
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unsigned short tx_loadsz;
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unsigned char fcr;
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unsigned char rxtrig_bytes[UART_FCR_R_TRIG_MAX_STATE];
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unsigned int flags;
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};
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#define UART_CAP_FIFO (1 << 8) /* UART has FIFO */
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#define UART_CAP_EFR (1 << 9) /* UART has EFR */
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#define UART_CAP_SLEEP (1 << 10) /* UART has IER sleep */
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#define UART_CAP_AFE (1 << 11) /* MCR-based hw flow control */
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#define UART_CAP_UUE (1 << 12) /* UART needs IER bit 6 set (Xscale) */
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#define UART_CAP_RTOIE (1 << 13) /* UART needs IER bit 4 set (Xscale, Tegra) */
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#define UART_CAP_HFIFO (1 << 14) /* UART has a "hidden" FIFO */
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#define UART_CAP_RPM (1 << 15) /* Runtime PM is active while idle */
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#define UART_CAP_IRDA (1 << 16) /* UART supports IrDA line discipline */
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#define UART_CAP_MINI (1 << 17) /* Mini UART on BCM283X family lacks:
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* STOP PARITY EPAR SPAR WLEN5 WLEN6
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*/
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#define UART_BUG_QUOT (1 << 0) /* UART has buggy quot LSB */
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#define UART_BUG_TXEN (1 << 1) /* UART has buggy TX IIR status */
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#define UART_BUG_NOMSR (1 << 2) /* UART has buggy MSR status bits (Au1x00) */
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#define UART_BUG_THRE (1 << 3) /* UART has buggy THRE reassertion */
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#define UART_BUG_PARITY (1 << 4) /* UART mishandles parity if FIFO enabled */
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#ifdef CONFIG_SERIAL_8250_SHARE_IRQ
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#define SERIAL8250_SHARE_IRQS 1
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#else
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#define SERIAL8250_SHARE_IRQS 0
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#endif
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#define SERIAL8250_PORT_FLAGS(_base, _irq, _flags) \
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{ \
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.iobase = _base, \
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.irq = _irq, \
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.uartclk = 1843200, \
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.iotype = UPIO_PORT, \
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.flags = UPF_BOOT_AUTOCONF | (_flags), \
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}
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#define SERIAL8250_PORT(_base, _irq) SERIAL8250_PORT_FLAGS(_base, _irq, 0)
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static inline int serial_in(struct uart_8250_port *up, int offset)
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{
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return up->port.serial_in(&up->port, offset);
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}
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static inline void serial_out(struct uart_8250_port *up, int offset, int value)
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{
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up->port.serial_out(&up->port, offset, value);
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}
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void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p);
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static inline int serial_dl_read(struct uart_8250_port *up)
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{
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return up->dl_read(up);
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}
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static inline void serial_dl_write(struct uart_8250_port *up, int value)
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{
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up->dl_write(up, value);
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}
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struct uart_8250_port *serial8250_get_port(int line);
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void serial8250_rpm_get(struct uart_8250_port *p);
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void serial8250_rpm_put(struct uart_8250_port *p);
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void serial8250_rpm_get_tx(struct uart_8250_port *p);
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void serial8250_rpm_put_tx(struct uart_8250_port *p);
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int serial8250_em485_init(struct uart_8250_port *p);
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void serial8250_em485_destroy(struct uart_8250_port *p);
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static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
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{
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serial_out(up, UART_MCR, value);
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}
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static inline int serial8250_in_MCR(struct uart_8250_port *up)
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{
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return serial_in(up, UART_MCR);
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}
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#if defined(__alpha__) && !defined(CONFIG_PCI)
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/*
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* Digital did something really horribly wrong with the OUT1 and OUT2
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* lines on at least some ALPHA's. The failure mode is that if either
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* is cleared, the machine locks up with endless interrupts.
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*/
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#define ALPHA_KLUDGE_MCR (UART_MCR_OUT2 | UART_MCR_OUT1)
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#else
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#define ALPHA_KLUDGE_MCR 0
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#endif
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#ifdef CONFIG_SERIAL_8250_PNP
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int serial8250_pnp_init(void);
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void serial8250_pnp_exit(void);
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#else
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static inline int serial8250_pnp_init(void) { return 0; }
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static inline void serial8250_pnp_exit(void) { }
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#endif
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#ifdef CONFIG_SERIAL_8250_FINTEK
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int fintek_8250_probe(struct uart_8250_port *uart);
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#else
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static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; }
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#endif
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#ifdef CONFIG_ARCH_OMAP1
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static inline int is_omap1_8250(struct uart_8250_port *pt)
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{
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int res;
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switch (pt->port.mapbase) {
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case OMAP1_UART1_BASE:
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case OMAP1_UART2_BASE:
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case OMAP1_UART3_BASE:
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res = 1;
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break;
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default:
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res = 0;
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break;
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}
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return res;
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}
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static inline int is_omap1510_8250(struct uart_8250_port *pt)
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{
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if (!cpu_is_omap1510())
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return 0;
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return is_omap1_8250(pt);
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}
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#else
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static inline int is_omap1_8250(struct uart_8250_port *pt)
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{
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return 0;
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}
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static inline int is_omap1510_8250(struct uart_8250_port *pt)
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{
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return 0;
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}
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#endif
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#ifdef CONFIG_SERIAL_8250_DMA
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extern int serial8250_tx_dma(struct uart_8250_port *);
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extern int serial8250_rx_dma(struct uart_8250_port *);
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extern void serial8250_rx_dma_flush(struct uart_8250_port *);
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extern int serial8250_request_dma(struct uart_8250_port *);
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extern void serial8250_release_dma(struct uart_8250_port *);
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#else
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static inline int serial8250_tx_dma(struct uart_8250_port *p)
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{
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return -1;
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}
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static inline int serial8250_rx_dma(struct uart_8250_port *p)
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{
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return -1;
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}
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static inline void serial8250_rx_dma_flush(struct uart_8250_port *p) { }
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static inline int serial8250_request_dma(struct uart_8250_port *p)
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{
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return -1;
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}
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static inline void serial8250_release_dma(struct uart_8250_port *p) { }
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#endif
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static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
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{
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unsigned char status;
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status = serial_in(up, 0x04); /* EXCR2 */
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#define PRESL(x) ((x) & 0x30)
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if (PRESL(status) == 0x10) {
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/* already in high speed mode */
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return 0;
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} else {
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status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
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status |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
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serial_out(up, 0x04, status);
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}
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return 1;
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}
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static inline int serial_index(struct uart_port *port)
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{
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return port->minor - 64;
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}
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