1// SPDX-License-Identifier: GPL-2.0+ 2/* 3 * (C) Copyright 2013-2016 Freescale Semiconductor, Inc. 4 */ 5 6#include <common.h> 7#include <dm.h> 8#include <errno.h> 9#include <watchdog.h> 10#include <asm/global_data.h> 11#include <asm/io.h> 12#include <serial.h> 13#include <linux/compiler.h> 14#include <asm/arch/imx-regs.h> 15#include <asm/arch/clock.h> 16 17#define US1_TDRE (1 << 7) 18#define US1_RDRF (1 << 5) 19#define UC2_TE (1 << 3) 20#define LINCR1_INIT (1 << 0) 21#define LINCR1_MME (1 << 4) 22#define LINCR1_BF (1 << 7) 23#define LINSR_LINS_INITMODE (0x00001000) 24#define LINSR_LINS_MASK (0x0000F000) 25#define UARTCR_UART (1 << 0) 26#define UARTCR_WL0 (1 << 1) 27#define UARTCR_PCE (1 << 2) 28#define UARTCR_PC0 (1 << 3) 29#define UARTCR_TXEN (1 << 4) 30#define UARTCR_RXEN (1 << 5) 31#define UARTCR_PC1 (1 << 6) 32#define UARTSR_DTF (1 << 1) 33#define UARTSR_DRF (1 << 2) 34#define UARTSR_RMB (1 << 9) 35 36DECLARE_GLOBAL_DATA_PTR; 37 38static void _linflex_serial_setbrg(struct linflex_fsl *base, int baudrate) 39{ 40 u32 clk = mxc_get_clock(MXC_UART_CLK); 41 u32 ibr, fbr; 42 43 if (!baudrate) 44 baudrate = CONFIG_BAUDRATE; 45 46 ibr = (u32) (clk / (16 * gd->baudrate)); 47 fbr = (u32) (clk % (16 * gd->baudrate)) * 16; 48 49 __raw_writel(ibr, &base->linibrr); 50 __raw_writel(fbr, &base->linfbrr); 51} 52 53static int _linflex_serial_getc(struct linflex_fsl *base) 54{ 55 char c; 56 57 if (!(__raw_readb(&base->uartsr) & UARTSR_DRF)) 58 return -EAGAIN; 59 60 if (!(__raw_readl(&base->uartsr) & UARTSR_RMB)) 61 return -EAGAIN; 62 63 c = __raw_readl(&base->bdrm); 64 __raw_writeb((__raw_readb(&base->uartsr) | (UARTSR_DRF | UARTSR_RMB)), 65 &base->uartsr); 66 return c; 67} 68 69static int _linflex_serial_putc(struct linflex_fsl *base, const char c) 70{ 71 __raw_writeb(c, &base->bdrl); 72 73 74 if (!(__raw_readb(&base->uartsr) & UARTSR_DTF)) 75 return -EAGAIN; 76 77 __raw_writeb((__raw_readb(&base->uartsr) | UARTSR_DTF), &base->uartsr); 78 79 return 0; 80} 81 82/* 83 * Initialise the serial port with the given baudrate. The settings 84 * are always 8 data bits, no parity, 1 stop bit, no start bits. 85 */ 86static int _linflex_serial_init(struct linflex_fsl *base) 87{ 88 volatile u32 ctrl; 89 90 /* set the Linflex in master mode amd activate by-pass filter */ 91 ctrl = LINCR1_BF | LINCR1_MME; 92 __raw_writel(ctrl, &base->lincr1); 93 94 /* init mode */ 95 ctrl |= LINCR1_INIT; 96 __raw_writel(ctrl, &base->lincr1); 97 98 /* waiting for init mode entry - TODO: add a timeout */ 99 while ((__raw_readl(&base->linsr) & LINSR_LINS_MASK) != 100 LINSR_LINS_INITMODE); 101 102 /* set UART bit to allow writing other bits */ 103 __raw_writel(UARTCR_UART, &base->uartcr); 104 105 /* provide data bits, parity, stop bit, etc */ 106 serial_setbrg(); 107 108 /* 8 bit data, no parity, Tx and Rx enabled, UART mode */ 109 __raw_writel(UARTCR_PC1 | UARTCR_RXEN | UARTCR_TXEN | UARTCR_PC0 110 | UARTCR_WL0 | UARTCR_UART, &base->uartcr); 111 112 ctrl = __raw_readl(&base->lincr1); 113 ctrl &= ~LINCR1_INIT; 114 __raw_writel(ctrl, &base->lincr1); /* end init mode */ 115 116 return 0; 117} 118 119struct linflex_serial_plat { 120 struct linflex_fsl *base_addr; 121 u8 port_id; /* do we need this? */ 122}; 123 124struct linflex_serial_priv { 125 struct linflex_fsl *lfuart; 126}; 127 128int linflex_serial_setbrg(struct udevice *dev, int baudrate) 129{ 130 struct linflex_serial_priv *priv = dev_get_priv(dev); 131 132 _linflex_serial_setbrg(priv->lfuart, baudrate); 133 134 return 0; 135} 136 137static int linflex_serial_getc(struct udevice *dev) 138{ 139 struct linflex_serial_priv *priv = dev_get_priv(dev); 140 141 return _linflex_serial_getc(priv->lfuart); 142} 143 144static int linflex_serial_putc(struct udevice *dev, const char ch) 145{ 146 147 struct linflex_serial_priv *priv = dev_get_priv(dev); 148 149 return _linflex_serial_putc(priv->lfuart, ch); 150} 151 152static int linflex_serial_pending(struct udevice *dev, bool input) 153{ 154 struct linflex_serial_priv *priv = dev_get_priv(dev); 155 uint32_t uartsr = __raw_readl(&priv->lfuart->uartsr); 156 157 if (input) 158 return ((uartsr & UARTSR_DRF) && (uartsr & UARTSR_RMB)) ? 1 : 0; 159 else 160 return uartsr & UARTSR_DTF ? 0 : 1; 161} 162 163static void linflex_serial_init_internal(struct linflex_fsl *lfuart) 164{ 165 _linflex_serial_init(lfuart); 166 _linflex_serial_setbrg(lfuart, CONFIG_BAUDRATE); 167 return; 168} 169 170static int linflex_serial_probe(struct udevice *dev) 171{ 172 struct linflex_serial_plat *plat = dev_get_plat(dev); 173 struct linflex_serial_priv *priv = dev_get_priv(dev); 174 175 priv->lfuart = (struct linflex_fsl *)plat->base_addr; 176 linflex_serial_init_internal(priv->lfuart); 177 178 return 0; 179} 180 181static const struct dm_serial_ops linflex_serial_ops = { 182 .putc = linflex_serial_putc, 183 .pending = linflex_serial_pending, 184 .getc = linflex_serial_getc, 185 .setbrg = linflex_serial_setbrg, 186}; 187 188U_BOOT_DRIVER(serial_linflex) = { 189 .name = "serial_linflex", 190 .id = UCLASS_SERIAL, 191 .probe = linflex_serial_probe, 192 .ops = &linflex_serial_ops, 193 .flags = DM_FLAG_PRE_RELOC, 194 .priv_auto = sizeof(struct linflex_serial_priv), 195}; 196 197#ifdef CONFIG_DEBUG_UART_LINFLEXUART 198 199#include <debug_uart.h> 200 201 202static inline void _debug_uart_init(void) 203{ 204 struct linflex_fsl *base = (struct linflex_fsl *)CONFIG_VAL(DEBUG_UART_BASE); 205 206 linflex_serial_init_internal(base); 207} 208 209static inline void _debug_uart_putc(int ch) 210{ 211 struct linflex_fsl *base = (struct linflex_fsl *)CONFIG_VAL(DEBUG_UART_BASE); 212 213 /* XXX: Is this OK? Should this use the non-DM version? */ 214 _linflex_serial_putc(base, ch); 215} 216 217DEBUG_UART_FUNCS 218 219#endif /* CONFIG_DEBUG_UART_LINFLEXUART */ 220