1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Driver for 8250/16550-type serial ports
4 *
5 * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
6 *
7 * Copyright (C) 2001 Russell King.
8 */
9
10 #include <linux/serial_8250.h>
11 #include <linux/serial_reg.h>
12 #include <linux/dmaengine.h>
13
14 struct uart_8250_dma {
15 int (*tx_dma)(struct uart_8250_port *p);
16 int (*rx_dma)(struct uart_8250_port *p);
17
18 /* Filter function */
19 dma_filter_fn fn;
20 /* Parameter to the filter function */
21 void *rx_param;
22 void *tx_param;
23
24 struct dma_slave_config rxconf;
25 struct dma_slave_config txconf;
26
27 struct dma_chan *rxchan;
28 struct dma_chan *txchan;
29
30 /* Device address base for DMA operations */
31 phys_addr_t rx_dma_addr;
32 phys_addr_t tx_dma_addr;
33
34 /* DMA address of the buffer in memory */
35 dma_addr_t rx_addr;
36 dma_addr_t tx_addr;
37
38 dma_cookie_t rx_cookie;
39 dma_cookie_t tx_cookie;
40
41 void *rx_buf;
42
43 size_t rx_size;
44 size_t tx_size;
45
46 unsigned char tx_running;
47 unsigned char tx_err;
48 unsigned char rx_running;
49 };
50
51 struct old_serial_port {
52 unsigned int uart;
53 unsigned int baud_base;
54 unsigned int port;
55 unsigned int irq;
56 upf_t flags;
57 unsigned char io_type;
58 unsigned char __iomem *iomem_base;
59 unsigned short iomem_reg_shift;
60 };
61
62 struct serial8250_config {
63 const char *name;
64 unsigned short fifo_size;
65 unsigned short tx_loadsz;
66 unsigned char fcr;
67 unsigned char rxtrig_bytes[UART_FCR_R_TRIG_MAX_STATE];
68 unsigned int flags;
69 };
70
71 #define UART_CAP_FIFO (1 << 8) /* UART has FIFO */
72 #define UART_CAP_EFR (1 << 9) /* UART has EFR */
73 #define UART_CAP_SLEEP (1 << 10) /* UART has IER sleep */
74 #define UART_CAP_AFE (1 << 11) /* MCR-based hw flow control */
75 #define UART_CAP_UUE (1 << 12) /* UART needs IER bit 6 set (Xscale) */
76 #define UART_CAP_RTOIE (1 << 13) /* UART needs IER bit 4 set (Xscale, Tegra) */
77 #define UART_CAP_HFIFO (1 << 14) /* UART has a "hidden" FIFO */
78 #define UART_CAP_RPM (1 << 15) /* Runtime PM is active while idle */
79 #define UART_CAP_IRDA (1 << 16) /* UART supports IrDA line discipline */
80 #define UART_CAP_MINI (1 << 17) /* Mini UART on BCM283X family lacks:
81 * STOP PARITY EPAR SPAR WLEN5 WLEN6
82 */
83
84 #define UART_BUG_QUOT (1 << 0) /* UART has buggy quot LSB */
85 #define UART_BUG_TXEN (1 << 1) /* UART has buggy TX IIR status */
86 #define UART_BUG_NOMSR (1 << 2) /* UART has buggy MSR status bits (Au1x00) */
87 #define UART_BUG_THRE (1 << 3) /* UART has buggy THRE reassertion */
88 #define UART_BUG_PARITY (1 << 4) /* UART mishandles parity if FIFO enabled */
89
90
91 #ifdef CONFIG_SERIAL_8250_SHARE_IRQ
92 #define SERIAL8250_SHARE_IRQS 1
93 #else
94 #define SERIAL8250_SHARE_IRQS 0
95 #endif
96
97 #define SERIAL8250_PORT_FLAGS(_base, _irq, _flags) \
98 { \
99 .iobase = _base, \
100 .irq = _irq, \
101 .uartclk = 1843200, \
102 .iotype = UPIO_PORT, \
103 .flags = UPF_BOOT_AUTOCONF | (_flags), \
104 }
105
106 #define SERIAL8250_PORT(_base, _irq) SERIAL8250_PORT_FLAGS(_base, _irq, 0)
107
108
serial_in(struct uart_8250_port * up,int offset)109 static inline int serial_in(struct uart_8250_port *up, int offset)
110 {
111 return up->port.serial_in(&up->port, offset);
112 }
113
serial_out(struct uart_8250_port * up,int offset,int value)114 static inline void serial_out(struct uart_8250_port *up, int offset, int value)
115 {
116 up->port.serial_out(&up->port, offset, value);
117 }
118
119 void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p);
120
serial_dl_read(struct uart_8250_port * up)121 static inline int serial_dl_read(struct uart_8250_port *up)
122 {
123 return up->dl_read(up);
124 }
125
serial_dl_write(struct uart_8250_port * up,int value)126 static inline void serial_dl_write(struct uart_8250_port *up, int value)
127 {
128 up->dl_write(up, value);
129 }
130
131 struct uart_8250_port *serial8250_get_port(int line);
132
133 void serial8250_rpm_get(struct uart_8250_port *p);
134 void serial8250_rpm_put(struct uart_8250_port *p);
135
136 void serial8250_rpm_get_tx(struct uart_8250_port *p);
137 void serial8250_rpm_put_tx(struct uart_8250_port *p);
138
139 int serial8250_em485_init(struct uart_8250_port *p);
140 void serial8250_em485_destroy(struct uart_8250_port *p);
141
serial8250_out_MCR(struct uart_8250_port * up,int value)142 static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
143 {
144 serial_out(up, UART_MCR, value);
145 }
146
serial8250_in_MCR(struct uart_8250_port * up)147 static inline int serial8250_in_MCR(struct uart_8250_port *up)
148 {
149 return serial_in(up, UART_MCR);
150 }
151
152 #if defined(__alpha__) && !defined(CONFIG_PCI)
153 /*
154 * Digital did something really horribly wrong with the OUT1 and OUT2
155 * lines on at least some ALPHA's. The failure mode is that if either
156 * is cleared, the machine locks up with endless interrupts.
157 */
158 #define ALPHA_KLUDGE_MCR (UART_MCR_OUT2 | UART_MCR_OUT1)
159 #else
160 #define ALPHA_KLUDGE_MCR 0
161 #endif
162
163 #ifdef CONFIG_SERIAL_8250_PNP
164 int serial8250_pnp_init(void);
165 void serial8250_pnp_exit(void);
166 #else
serial8250_pnp_init(void)167 static inline int serial8250_pnp_init(void) { return 0; }
serial8250_pnp_exit(void)168 static inline void serial8250_pnp_exit(void) { }
169 #endif
170
171 #ifdef CONFIG_SERIAL_8250_FINTEK
172 int fintek_8250_probe(struct uart_8250_port *uart);
173 #else
fintek_8250_probe(struct uart_8250_port * uart)174 static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; }
175 #endif
176
177 #ifdef CONFIG_ARCH_OMAP1
is_omap1_8250(struct uart_8250_port * pt)178 static inline int is_omap1_8250(struct uart_8250_port *pt)
179 {
180 int res;
181
182 switch (pt->port.mapbase) {
183 case OMAP1_UART1_BASE:
184 case OMAP1_UART2_BASE:
185 case OMAP1_UART3_BASE:
186 res = 1;
187 break;
188 default:
189 res = 0;
190 break;
191 }
192
193 return res;
194 }
195
is_omap1510_8250(struct uart_8250_port * pt)196 static inline int is_omap1510_8250(struct uart_8250_port *pt)
197 {
198 if (!cpu_is_omap1510())
199 return 0;
200
201 return is_omap1_8250(pt);
202 }
203 #else
is_omap1_8250(struct uart_8250_port * pt)204 static inline int is_omap1_8250(struct uart_8250_port *pt)
205 {
206 return 0;
207 }
is_omap1510_8250(struct uart_8250_port * pt)208 static inline int is_omap1510_8250(struct uart_8250_port *pt)
209 {
210 return 0;
211 }
212 #endif
213
214 #ifdef CONFIG_SERIAL_8250_DMA
215 extern int serial8250_tx_dma(struct uart_8250_port *);
216 extern int serial8250_rx_dma(struct uart_8250_port *);
217 extern void serial8250_rx_dma_flush(struct uart_8250_port *);
218 extern int serial8250_request_dma(struct uart_8250_port *);
219 extern void serial8250_release_dma(struct uart_8250_port *);
220 #else
serial8250_tx_dma(struct uart_8250_port * p)221 static inline int serial8250_tx_dma(struct uart_8250_port *p)
222 {
223 return -1;
224 }
serial8250_rx_dma(struct uart_8250_port * p)225 static inline int serial8250_rx_dma(struct uart_8250_port *p)
226 {
227 return -1;
228 }
serial8250_rx_dma_flush(struct uart_8250_port * p)229 static inline void serial8250_rx_dma_flush(struct uart_8250_port *p) { }
serial8250_request_dma(struct uart_8250_port * p)230 static inline int serial8250_request_dma(struct uart_8250_port *p)
231 {
232 return -1;
233 }
serial8250_release_dma(struct uart_8250_port * p)234 static inline void serial8250_release_dma(struct uart_8250_port *p) { }
235 #endif
236
ns16550a_goto_highspeed(struct uart_8250_port * up)237 static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)
238 {
239 unsigned char status;
240
241 status = serial_in(up, 0x04); /* EXCR2 */
242 #define PRESL(x) ((x) & 0x30)
243 if (PRESL(status) == 0x10) {
244 /* already in high speed mode */
245 return 0;
246 } else {
247 status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */
248 status |= 0x10; /* 1.625 divisor for baud_base --> 921600 */
249 serial_out(up, 0x04, status);
250 }
251 return 1;
252 }
253
serial_index(struct uart_port * port)254 static inline int serial_index(struct uart_port *port)
255 {
256 return port->minor - 64;
257 }
258
