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1// SPDX-License-Identifier: GPL-2.02/*3 * RT288x/Au1xxx driver4 */5 6#include <linux/module.h>7#include <linux/io.h>8#include <linux/init.h>9#include <linux/console.h>10#include <linux/serial.h>11#include <linux/serial_8250.h>12 13#include "8250.h"14 15#define RT288X_DL 0x2816 17/* Au1x00/RT288x UART hardware has a weird register layout */18static const u8 au_io_in_map[7] = {19 [UART_RX] = 0,20 [UART_IER] = 2,21 [UART_IIR] = 3,22 [UART_LCR] = 5,23 [UART_MCR] = 6,24 [UART_LSR] = 7,25 [UART_MSR] = 8,26};27 28static const u8 au_io_out_map[5] = {29 [UART_TX] = 1,30 [UART_IER] = 2,31 [UART_FCR] = 4,32 [UART_LCR] = 5,33 [UART_MCR] = 6,34};35 36static unsigned int au_serial_in(struct uart_port *p, int offset)37{38 if (offset >= ARRAY_SIZE(au_io_in_map))39 return UINT_MAX;40 offset = au_io_in_map[offset];41 42 return __raw_readl(p->membase + (offset << p->regshift));43}44 45static void au_serial_out(struct uart_port *p, int offset, int value)46{47 if (offset >= ARRAY_SIZE(au_io_out_map))48 return;49 offset = au_io_out_map[offset];50 51 __raw_writel(value, p->membase + (offset << p->regshift));52}53 54/* Au1x00 haven't got a standard divisor latch */55static u32 au_serial_dl_read(struct uart_8250_port *up)56{57 return __raw_readl(up->port.membase + RT288X_DL);58}59 60static void au_serial_dl_write(struct uart_8250_port *up, u32 value)61{62 __raw_writel(value, up->port.membase + RT288X_DL);63}64 65int au_platform_setup(struct plat_serial8250_port *p)66{67 p->iotype = UPIO_AU;68 69 p->serial_in = au_serial_in;70 p->serial_out = au_serial_out;71 p->dl_read = au_serial_dl_read;72 p->dl_write = au_serial_dl_write;73 74 p->mapsize = 0x1000;75 76 p->bugs |= UART_BUG_NOMSR;77 78 return 0;79}80EXPORT_SYMBOL_GPL(au_platform_setup);81 82int rt288x_setup(struct uart_port *p)83{84 struct uart_8250_port *up = up_to_u8250p(p);85 86 p->iotype = UPIO_AU;87 88 p->serial_in = au_serial_in;89 p->serial_out = au_serial_out;90 up->dl_read = au_serial_dl_read;91 up->dl_write = au_serial_dl_write;92 93 p->mapsize = 0x100;94 95 up->bugs |= UART_BUG_NOMSR;96 97 return 0;98}99EXPORT_SYMBOL_GPL(rt288x_setup);100 101#ifdef CONFIG_SERIAL_8250_CONSOLE102static void au_putc(struct uart_port *port, unsigned char c)103{104 unsigned int status;105 106 au_serial_out(port, UART_TX, c);107 108 for (;;) {109 status = au_serial_in(port, UART_LSR);110 if (uart_lsr_tx_empty(status))111 break;112 cpu_relax();113 }114}115 116static void au_early_serial8250_write(struct console *console,117 const char *s, unsigned int count)118{119 struct earlycon_device *device = console->data;120 struct uart_port *port = &device->port;121 122 uart_console_write(port, s, count, au_putc);123}124 125static int __init early_au_setup(struct earlycon_device *dev, const char *opt)126{127 rt288x_setup(&dev->port);128 dev->con->write = au_early_serial8250_write;129 130 return 0;131}132OF_EARLYCON_DECLARE(palmchip, "ralink,rt2880-uart", early_au_setup);133#endif134 135MODULE_DESCRIPTION("RT288x/Au1xxx UART driver");136MODULE_LICENSE("GPL");137