1 /* SPDX-License-Identifier: GPL-2.0+ */
3 * Driver for 8250/16550-type serial ports
5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
7 * Copyright (C) 2001 Russell King.
10 #include <linux/serial_8250.h>
11 #include <linux/serial_reg.h>
12 #include <linux/dmaengine.h>
14 #include "../serial_mctrl_gpio.h"
16 struct uart_8250_dma {
17 int (*tx_dma)(struct uart_8250_port *p);
18 int (*rx_dma)(struct uart_8250_port *p);
22 /* Parameter to the filter function */
26 struct dma_slave_config rxconf;
27 struct dma_slave_config txconf;
29 struct dma_chan *rxchan;
30 struct dma_chan *txchan;
32 /* Device address base for DMA operations */
33 phys_addr_t rx_dma_addr;
34 phys_addr_t tx_dma_addr;
36 /* DMA address of the buffer in memory */
40 dma_cookie_t rx_cookie;
41 dma_cookie_t tx_cookie;
48 unsigned char tx_running;
50 unsigned char rx_running;
53 struct old_serial_port {
55 unsigned int baud_base;
59 unsigned char io_type;
60 unsigned char __iomem *iomem_base;
61 unsigned short iomem_reg_shift;
64 struct serial8250_config {
66 unsigned short fifo_size;
67 unsigned short tx_loadsz;
69 unsigned char rxtrig_bytes[UART_FCR_R_TRIG_MAX_STATE];
73 #define UART_CAP_FIFO (1 << 8) /* UART has FIFO */
74 #define UART_CAP_EFR (1 << 9) /* UART has EFR */
75 #define UART_CAP_SLEEP (1 << 10) /* UART has IER sleep */
76 #define UART_CAP_AFE (1 << 11) /* MCR-based hw flow control */
77 #define UART_CAP_UUE (1 << 12) /* UART needs IER bit 6 set (Xscale) */
78 #define UART_CAP_RTOIE (1 << 13) /* UART needs IER bit 4 set (Xscale, Tegra) */
79 #define UART_CAP_HFIFO (1 << 14) /* UART has a "hidden" FIFO */
80 #define UART_CAP_RPM (1 << 15) /* Runtime PM is active while idle */
81 #define UART_CAP_IRDA (1 << 16) /* UART supports IrDA line discipline */
82 #define UART_CAP_MINI (1 << 17) /* Mini UART on BCM283X family lacks:
83 * STOP PARITY EPAR SPAR WLEN5 WLEN6
86 #define UART_BUG_QUOT (1 << 0) /* UART has buggy quot LSB */
87 #define UART_BUG_TXEN (1 << 1) /* UART has buggy TX IIR status */
88 #define UART_BUG_NOMSR (1 << 2) /* UART has buggy MSR status bits (Au1x00) */
89 #define UART_BUG_THRE (1 << 3) /* UART has buggy THRE reassertion */
90 #define UART_BUG_TXRACE (1 << 5) /* UART Tx fails to set remote DR */
93 #ifdef CONFIG_SERIAL_8250_SHARE_IRQ
94 #define SERIAL8250_SHARE_IRQS 1
96 #define SERIAL8250_SHARE_IRQS 0
99 #define SERIAL8250_PORT_FLAGS(_base, _irq, _flags) \
103 .uartclk = 1843200, \
104 .iotype = UPIO_PORT, \
105 .flags = UPF_BOOT_AUTOCONF | (_flags), \
108 #define SERIAL8250_PORT(_base, _irq) SERIAL8250_PORT_FLAGS(_base, _irq, 0)
111 static inline int serial_in(struct uart_8250_port *up, int offset)
113 return up->port.serial_in(&up->port, offset);
116 static inline void serial_out(struct uart_8250_port *up, int offset, int value)
118 up->port.serial_out(&up->port, offset, value);
124 static void serial_icr_write(struct uart_8250_port *up, int offset, int value)
126 serial_out(up, UART_SCR, offset);
127 serial_out(up, UART_ICR, value);
130 static unsigned int __maybe_unused serial_icr_read(struct uart_8250_port *up,
135 serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);
136 serial_out(up, UART_SCR, offset);
137 value = serial_in(up, UART_ICR);
138 serial_icr_write(up, UART_ACR, up->acr);
143 void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p);
145 static inline int serial_dl_read(struct uart_8250_port *up)
147 return up->dl_read(up);
150 static inline void serial_dl_write(struct uart_8250_port *up, int value)
152 up->dl_write(up, value);
155 static inline bool serial8250_set_THRI(struct uart_8250_port *up)
157 if (up->ier & UART_IER_THRI)
159 up->ier |= UART_IER_THRI;
160 serial_out(up, UART_IER, up->ier);
164 static inline bool serial8250_clear_THRI(struct uart_8250_port *up)
166 if (!(up->ier & UART_IER_THRI))
168 up->ier &= ~UART_IER_THRI;
169 serial_out(up, UART_IER, up->ier);
173 struct uart_8250_port *serial8250_get_port(int line);
175 void serial8250_rpm_get(struct uart_8250_port *p);
176 void serial8250_rpm_put(struct uart_8250_port *p);
178 void serial8250_rpm_get_tx(struct uart_8250_port *p);
179 void serial8250_rpm_put_tx(struct uart_8250_port *p);
181 int serial8250_em485_config(struct uart_port *port, struct serial_rs485 *rs485);
182 void serial8250_em485_start_tx(struct uart_8250_port *p);
183 void serial8250_em485_stop_tx(struct uart_8250_port *p);
184 void serial8250_em485_destroy(struct uart_8250_port *p);
186 /* MCR <-> TIOCM conversion */
187 static inline int serial8250_TIOCM_to_MCR(int tiocm)
191 if (tiocm & TIOCM_RTS)
193 if (tiocm & TIOCM_DTR)
195 if (tiocm & TIOCM_OUT1)
196 mcr |= UART_MCR_OUT1;
197 if (tiocm & TIOCM_OUT2)
198 mcr |= UART_MCR_OUT2;
199 if (tiocm & TIOCM_LOOP)
200 mcr |= UART_MCR_LOOP;
205 static inline int serial8250_MCR_to_TIOCM(int mcr)
209 if (mcr & UART_MCR_RTS)
211 if (mcr & UART_MCR_DTR)
213 if (mcr & UART_MCR_OUT1)
215 if (mcr & UART_MCR_OUT2)
217 if (mcr & UART_MCR_LOOP)
223 /* MSR <-> TIOCM conversion */
224 static inline int serial8250_MSR_to_TIOCM(int msr)
228 if (msr & UART_MSR_DCD)
230 if (msr & UART_MSR_RI)
232 if (msr & UART_MSR_DSR)
234 if (msr & UART_MSR_CTS)
240 static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
242 serial_out(up, UART_MCR, value);
245 mctrl_gpio_set(up->gpios, serial8250_MCR_to_TIOCM(value));
248 static inline int serial8250_in_MCR(struct uart_8250_port *up)
252 mctrl = serial_in(up, UART_MCR);
255 unsigned int mctrl_gpio = 0;
257 mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio);
258 mctrl |= serial8250_TIOCM_to_MCR(mctrl_gpio);
264 #if defined(__alpha__) && !defined(CONFIG_PCI)
266 * Digital did something really horribly wrong with the OUT1 and OUT2
267 * lines on at least some ALPHA's. The failure mode is that if either
268 * is cleared, the machine locks up with endless interrupts.
270 #define ALPHA_KLUDGE_MCR (UART_MCR_OUT2 | UART_MCR_OUT1)
272 #define ALPHA_KLUDGE_MCR 0
275 #ifdef CONFIG_SERIAL_8250_PNP
276 int serial8250_pnp_init(void);
277 void serial8250_pnp_exit(void);
279 static inline int serial8250_pnp_init(void) { return 0; }
280 static inline void serial8250_pnp_exit(void) { }
283 #ifdef CONFIG_SERIAL_8250_FINTEK
284 int fintek_8250_probe(struct uart_8250_port *uart);
286 static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; }
289 #ifdef CONFIG_ARCH_OMAP1
290 static inline int is_omap1_8250(struct uart_8250_port *pt)
294 switch (pt->port.mapbase) {
295 case OMAP1_UART1_BASE:
296 case OMAP1_UART2_BASE:
297 case OMAP1_UART3_BASE:
308 static inline int is_omap1510_8250(struct uart_8250_port *pt)
310 if (!cpu_is_omap1510())
313 return is_omap1_8250(pt);
316 static inline int is_omap1_8250(struct uart_8250_port *pt)
320 static inline int is_omap1510_8250(struct uart_8250_port *pt)
326 #ifdef CONFIG_SERIAL_8250_DMA
327 extern int serial8250_tx_dma(struct uart_8250_port *);
328 extern int serial8250_rx_dma(struct uart_8250_port *);
329 extern void serial8250_rx_dma_flush(struct uart_8250_port *);
330 extern int serial8250_request_dma(struct uart_8250_port *);
331 extern void serial8250_release_dma(struct uart_8250_port *);
333 static inline bool serial8250_tx_dma_running(struct uart_8250_port *p)
335 struct uart_8250_dma *dma = p->dma;
337 return dma && dma->tx_running;
340 static inline int serial8250_tx_dma(struct uart_8250_port *p)
344 static inline int serial8250_rx_dma(struct uart_8250_port *p)
348 static inline void serial8250_rx_dma_flush(struct uart_8250_port *p) { }
349 static inline int serial8250_request_dma(struct uart_8250_port *p)
353 static inline void serial8250_release_dma(struct uart_8250_port *p) { }
355 static inline bool serial8250_tx_dma_running(struct uart_8250_port *p)
361 static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
363 unsigned char status;
365 status = serial_in(up, 0x04); /* EXCR2 */
366 #define PRESL(x) ((x) & 0x30)
367 if (PRESL(status) == 0x10) {
368 /* already in high speed mode */
371 status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
372 status |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
373 serial_out(up, 0x04, status);
378 static inline int serial_index(struct uart_port *port)
380 return port->minor - 64;