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1/* SPDX-License-Identifier: GPL-2.0+ */2/*3 * Driver for 8250/16550-type serial ports4 *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/bits.h>11#include <linux/serial_8250.h>12#include <linux/serial_core.h>13#include <linux/dmaengine.h>14 15#include "../serial_mctrl_gpio.h"16 17struct uart_8250_dma {18 int (*tx_dma)(struct uart_8250_port *p);19 int (*rx_dma)(struct uart_8250_port *p);20 void (*prepare_tx_dma)(struct uart_8250_port *p);21 void (*prepare_rx_dma)(struct uart_8250_port *p);22 23 /* Filter function */24 dma_filter_fn fn;25 /* Parameter to the filter function */26 void *rx_param;27 void *tx_param;28 29 struct dma_slave_config rxconf;30 struct dma_slave_config txconf;31 32 struct dma_chan *rxchan;33 struct dma_chan *txchan;34 35 /* Device address base for DMA operations */36 phys_addr_t rx_dma_addr;37 phys_addr_t tx_dma_addr;38 39 /* DMA address of the buffer in memory */40 dma_addr_t rx_addr;41 dma_addr_t tx_addr;42 43 dma_cookie_t rx_cookie;44 dma_cookie_t tx_cookie;45 46 void *rx_buf;47 48 size_t rx_size;49 size_t tx_size;50 51 unsigned char tx_running;52 unsigned char tx_err;53 unsigned char rx_running;54};55 56struct old_serial_port {57 unsigned int uart;58 unsigned int baud_base;59 unsigned int port;60 unsigned int irq;61 upf_t flags;62 unsigned char io_type;63 unsigned char __iomem *iomem_base;64 unsigned short iomem_reg_shift;65};66 67struct serial8250_config {68 const char *name;69 unsigned short fifo_size;70 unsigned short tx_loadsz;71 unsigned char fcr;72 unsigned char rxtrig_bytes[UART_FCR_R_TRIG_MAX_STATE];73 unsigned int flags;74};75 76#define UART_CAP_FIFO BIT(8) /* UART has FIFO */77#define UART_CAP_EFR BIT(9) /* UART has EFR */78#define UART_CAP_SLEEP BIT(10) /* UART has IER sleep */79#define UART_CAP_AFE BIT(11) /* MCR-based hw flow control */80#define UART_CAP_UUE BIT(12) /* UART needs IER bit 6 set (Xscale) */81#define UART_CAP_RTOIE BIT(13) /* UART needs IER bit 4 set (Xscale, Tegra) */82#define UART_CAP_HFIFO BIT(14) /* UART has a "hidden" FIFO */83#define UART_CAP_RPM BIT(15) /* Runtime PM is active while idle */84#define UART_CAP_IRDA BIT(16) /* UART supports IrDA line discipline */85#define UART_CAP_MINI BIT(17) /* Mini UART on BCM283X family lacks:86 * STOP PARITY EPAR SPAR WLEN5 WLEN687 */88#define UART_CAP_NOTEMT BIT(18) /* UART without interrupt on TEMT available */89 90#define UART_BUG_QUOT BIT(0) /* UART has buggy quot LSB */91#define UART_BUG_TXEN BIT(1) /* UART has buggy TX IIR status */92#define UART_BUG_NOMSR BIT(2) /* UART has buggy MSR status bits (Au1x00) */93#define UART_BUG_THRE BIT(3) /* UART has buggy THRE reassertion */94#define UART_BUG_TXRACE BIT(5) /* UART Tx fails to set remote DR */95 96/* Module parameters */97#define UART_NR CONFIG_SERIAL_8250_NR_UARTS98 99extern unsigned int nr_uarts;100 101#ifdef CONFIG_SERIAL_8250_SHARE_IRQ102#define SERIAL8250_SHARE_IRQS 1103#else104#define SERIAL8250_SHARE_IRQS 0105#endif106 107extern unsigned int share_irqs;108extern unsigned int skip_txen_test;109 110#define SERIAL8250_PORT_FLAGS(_base, _irq, _flags) \111 { \112 .iobase = _base, \113 .irq = _irq, \114 .uartclk = 1843200, \115 .iotype = UPIO_PORT, \116 .flags = UPF_BOOT_AUTOCONF | (_flags), \117 }118 119#define SERIAL8250_PORT(_base, _irq) SERIAL8250_PORT_FLAGS(_base, _irq, 0)120 121extern struct uart_driver serial8250_reg;122void serial8250_register_ports(struct uart_driver *drv, struct device *dev);123 124/* Legacy ISA bus related APIs */125typedef void (*serial8250_isa_config_fn)(int, struct uart_port *, u32 *);126extern serial8250_isa_config_fn serial8250_isa_config;127 128void serial8250_isa_init_ports(void);129 130extern struct platform_device *serial8250_isa_devs;131 132extern const struct uart_ops *univ8250_port_base_ops;133extern struct uart_ops univ8250_port_ops;134 135static inline int serial_in(struct uart_8250_port *up, int offset)136{137 return up->port.serial_in(&up->port, offset);138}139 140static inline void serial_out(struct uart_8250_port *up, int offset, int value)141{142 up->port.serial_out(&up->port, offset, value);143}144 145/**146 * serial_lsr_in - Read LSR register and preserve flags across reads147 * @up: uart 8250 port148 *149 * Read LSR register and handle saving non-preserved flags across reads.150 * The flags that are not preserved across reads are stored into151 * up->lsr_saved_flags.152 *153 * Returns LSR value or'ed with the preserved flags (if any).154 */155static inline u16 serial_lsr_in(struct uart_8250_port *up)156{157 u16 lsr = up->lsr_saved_flags;158 159 lsr |= serial_in(up, UART_LSR);160 up->lsr_saved_flags = lsr & up->lsr_save_mask;161 162 return lsr;163}164 165/*166 * For the 16C950167 */168static void serial_icr_write(struct uart_8250_port *up, int offset, int value)169{170 serial_out(up, UART_SCR, offset);171 serial_out(up, UART_ICR, value);172}173 174static unsigned int __maybe_unused serial_icr_read(struct uart_8250_port *up,175 int offset)176{177 unsigned int value;178 179 serial_icr_write(up, UART_ACR, up->acr | UART_ACR_ICRRD);180 serial_out(up, UART_SCR, offset);181 value = serial_in(up, UART_ICR);182 serial_icr_write(up, UART_ACR, up->acr);183 184 return value;185}186 187void serial8250_clear_and_reinit_fifos(struct uart_8250_port *p);188 189static inline u32 serial_dl_read(struct uart_8250_port *up)190{191 return up->dl_read(up);192}193 194static inline void serial_dl_write(struct uart_8250_port *up, u32 value)195{196 up->dl_write(up, value);197}198 199static inline bool serial8250_set_THRI(struct uart_8250_port *up)200{201 /* Port locked to synchronize UART_IER access against the console. */202 lockdep_assert_held_once(&up->port.lock);203 204 if (up->ier & UART_IER_THRI)205 return false;206 up->ier |= UART_IER_THRI;207 serial_out(up, UART_IER, up->ier);208 return true;209}210 211static inline bool serial8250_clear_THRI(struct uart_8250_port *up)212{213 /* Port locked to synchronize UART_IER access against the console. */214 lockdep_assert_held_once(&up->port.lock);215 216 if (!(up->ier & UART_IER_THRI))217 return false;218 up->ier &= ~UART_IER_THRI;219 serial_out(up, UART_IER, up->ier);220 return true;221}222 223struct uart_8250_port *serial8250_setup_port(int index);224struct uart_8250_port *serial8250_get_port(int line);225 226void serial8250_rpm_get(struct uart_8250_port *p);227void serial8250_rpm_put(struct uart_8250_port *p);228 229void serial8250_rpm_get_tx(struct uart_8250_port *p);230void serial8250_rpm_put_tx(struct uart_8250_port *p);231 232int serial8250_em485_config(struct uart_port *port, struct ktermios *termios,233 struct serial_rs485 *rs485);234void serial8250_em485_start_tx(struct uart_8250_port *p);235void serial8250_em485_stop_tx(struct uart_8250_port *p);236void serial8250_em485_destroy(struct uart_8250_port *p);237extern struct serial_rs485 serial8250_em485_supported;238 239/* MCR <-> TIOCM conversion */240static inline int serial8250_TIOCM_to_MCR(int tiocm)241{242 int mcr = 0;243 244 if (tiocm & TIOCM_RTS)245 mcr |= UART_MCR_RTS;246 if (tiocm & TIOCM_DTR)247 mcr |= UART_MCR_DTR;248 if (tiocm & TIOCM_OUT1)249 mcr |= UART_MCR_OUT1;250 if (tiocm & TIOCM_OUT2)251 mcr |= UART_MCR_OUT2;252 if (tiocm & TIOCM_LOOP)253 mcr |= UART_MCR_LOOP;254 255 return mcr;256}257 258static inline int serial8250_MCR_to_TIOCM(int mcr)259{260 int tiocm = 0;261 262 if (mcr & UART_MCR_RTS)263 tiocm |= TIOCM_RTS;264 if (mcr & UART_MCR_DTR)265 tiocm |= TIOCM_DTR;266 if (mcr & UART_MCR_OUT1)267 tiocm |= TIOCM_OUT1;268 if (mcr & UART_MCR_OUT2)269 tiocm |= TIOCM_OUT2;270 if (mcr & UART_MCR_LOOP)271 tiocm |= TIOCM_LOOP;272 273 return tiocm;274}275 276/* MSR <-> TIOCM conversion */277static inline int serial8250_MSR_to_TIOCM(int msr)278{279 int tiocm = 0;280 281 if (msr & UART_MSR_DCD)282 tiocm |= TIOCM_CAR;283 if (msr & UART_MSR_RI)284 tiocm |= TIOCM_RNG;285 if (msr & UART_MSR_DSR)286 tiocm |= TIOCM_DSR;287 if (msr & UART_MSR_CTS)288 tiocm |= TIOCM_CTS;289 290 return tiocm;291}292 293static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)294{295 serial_out(up, UART_MCR, value);296 297 if (up->gpios)298 mctrl_gpio_set(up->gpios, serial8250_MCR_to_TIOCM(value));299}300 301static inline int serial8250_in_MCR(struct uart_8250_port *up)302{303 int mctrl;304 305 mctrl = serial_in(up, UART_MCR);306 307 if (up->gpios) {308 unsigned int mctrl_gpio = 0;309 310 mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio);311 mctrl |= serial8250_TIOCM_to_MCR(mctrl_gpio);312 }313 314 return mctrl;315}316 317#ifdef CONFIG_SERIAL_8250_PNP318int serial8250_pnp_init(void);319void serial8250_pnp_exit(void);320#else321static inline int serial8250_pnp_init(void) { return 0; }322static inline void serial8250_pnp_exit(void) { }323#endif324 325#ifdef CONFIG_SERIAL_8250_RSA326void univ8250_rsa_support(struct uart_ops *ops);327#else328static inline void univ8250_rsa_support(struct uart_ops *ops) { }329#endif330 331#ifdef CONFIG_SERIAL_8250_FINTEK332int fintek_8250_probe(struct uart_8250_port *uart);333#else334static inline int fintek_8250_probe(struct uart_8250_port *uart) { return 0; }335#endif336 337#ifdef CONFIG_ARCH_OMAP1338#include <linux/soc/ti/omap1-soc.h>339static inline int is_omap1_8250(struct uart_8250_port *pt)340{341 int res;342 343 switch (pt->port.mapbase) {344 case OMAP1_UART1_BASE:345 case OMAP1_UART2_BASE:346 case OMAP1_UART3_BASE:347 res = 1;348 break;349 default:350 res = 0;351 break;352 }353 354 return res;355}356 357static inline int is_omap1510_8250(struct uart_8250_port *pt)358{359 if (!cpu_is_omap1510())360 return 0;361 362 return is_omap1_8250(pt);363}364#else365static inline int is_omap1_8250(struct uart_8250_port *pt)366{367 return 0;368}369static inline int is_omap1510_8250(struct uart_8250_port *pt)370{371 return 0;372}373#endif374 375#ifdef CONFIG_SERIAL_8250_DMA376extern int serial8250_tx_dma(struct uart_8250_port *);377extern int serial8250_rx_dma(struct uart_8250_port *);378extern void serial8250_rx_dma_flush(struct uart_8250_port *);379extern int serial8250_request_dma(struct uart_8250_port *);380extern void serial8250_release_dma(struct uart_8250_port *);381 382static inline void serial8250_do_prepare_tx_dma(struct uart_8250_port *p)383{384 struct uart_8250_dma *dma = p->dma;385 386 if (dma->prepare_tx_dma)387 dma->prepare_tx_dma(p);388}389 390static inline void serial8250_do_prepare_rx_dma(struct uart_8250_port *p)391{392 struct uart_8250_dma *dma = p->dma;393 394 if (dma->prepare_rx_dma)395 dma->prepare_rx_dma(p);396}397 398static inline bool serial8250_tx_dma_running(struct uart_8250_port *p)399{400 struct uart_8250_dma *dma = p->dma;401 402 return dma && dma->tx_running;403}404#else405static inline int serial8250_tx_dma(struct uart_8250_port *p)406{407 return -1;408}409static inline int serial8250_rx_dma(struct uart_8250_port *p)410{411 return -1;412}413static inline void serial8250_rx_dma_flush(struct uart_8250_port *p) { }414static inline int serial8250_request_dma(struct uart_8250_port *p)415{416 return -1;417}418static inline void serial8250_release_dma(struct uart_8250_port *p) { }419 420static inline bool serial8250_tx_dma_running(struct uart_8250_port *p)421{422 return false;423}424#endif425 426static inline int ns16550a_goto_highspeed(struct uart_8250_port *up)427{428 unsigned char status;429 430 status = serial_in(up, 0x04); /* EXCR2 */431#define PRESL(x) ((x) & 0x30)432 if (PRESL(status) == 0x10) {433 /* already in high speed mode */434 return 0;435 } else {436 status &= ~0xB0; /* Disable LOCK, mask out PRESL[01] */437 status |= 0x10; /* 1.625 divisor for baud_base --> 921600 */438 serial_out(up, 0x04, status);439 }440 return 1;441}442 443static inline int serial_index(struct uart_port *port)444{445 return port->minor - 64;446}447