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