1 /* 2 * (C) Copyright 2013-2016 Freescale Semiconductor, Inc. 3 * 4 * SPDX-License-Identifier: GPL-2.0+ 5 */ 6 7 #include <common.h> 8 #include <dm.h> 9 #include <errno.h> 10 #include <watchdog.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 36 DECLARE_GLOBAL_DATA_PTR; 37 38 #ifndef CONFIG_DM_SERIAL 39 #error "The linflex serial driver does not have non-DM support." 40 #endif 41 42 static void _linflex_serial_setbrg(struct linflex_fsl *base, int baudrate) 43 { 44 u32 clk = mxc_get_clock(MXC_UART_CLK); 45 u32 ibr, fbr; 46 47 if (!baudrate) 48 baudrate = CONFIG_BAUDRATE; 49 50 ibr = (u32) (clk / (16 * gd->baudrate)); 51 fbr = (u32) (clk % (16 * gd->baudrate)) * 16; 52 53 __raw_writel(ibr, &base->linibrr); 54 __raw_writel(fbr, &base->linfbrr); 55 } 56 57 static int _linflex_serial_getc(struct linflex_fsl *base) 58 { 59 char c; 60 61 if (!(__raw_readb(&base->uartsr) & UARTSR_DRF)) 62 return -EAGAIN; 63 64 if (!(__raw_readl(&base->uartsr) & UARTSR_RMB)) 65 return -EAGAIN; 66 67 c = __raw_readl(&base->bdrm); 68 __raw_writeb((__raw_readb(&base->uartsr) | (UARTSR_DRF | UARTSR_RMB)), 69 &base->uartsr); 70 return c; 71 } 72 73 static int _linflex_serial_putc(struct linflex_fsl *base, const char c) 74 { 75 __raw_writeb(c, &base->bdrl); 76 77 78 if (!(__raw_readb(&base->uartsr) & UARTSR_DTF)) 79 return -EAGAIN; 80 81 __raw_writeb((__raw_readb(&base->uartsr) | UARTSR_DTF), &base->uartsr); 82 83 return 0; 84 } 85 86 /* 87 * Initialise the serial port with the given baudrate. The settings 88 * are always 8 data bits, no parity, 1 stop bit, no start bits. 89 */ 90 static int _linflex_serial_init(struct linflex_fsl *base) 91 { 92 volatile u32 ctrl; 93 94 /* set the Linflex in master mode amd activate by-pass filter */ 95 ctrl = LINCR1_BF | LINCR1_MME; 96 __raw_writel(ctrl, &base->lincr1); 97 98 /* init mode */ 99 ctrl |= LINCR1_INIT; 100 __raw_writel(ctrl, &base->lincr1); 101 102 /* waiting for init mode entry - TODO: add a timeout */ 103 while ((__raw_readl(&base->linsr) & LINSR_LINS_MASK) != 104 LINSR_LINS_INITMODE); 105 106 /* set UART bit to allow writing other bits */ 107 __raw_writel(UARTCR_UART, &base->uartcr); 108 109 /* provide data bits, parity, stop bit, etc */ 110 serial_setbrg(); 111 112 /* 8 bit data, no parity, Tx and Rx enabled, UART mode */ 113 __raw_writel(UARTCR_PC1 | UARTCR_RXEN | UARTCR_TXEN | UARTCR_PC0 114 | UARTCR_WL0 | UARTCR_UART, &base->uartcr); 115 116 ctrl = __raw_readl(&base->lincr1); 117 ctrl &= ~LINCR1_INIT; 118 __raw_writel(ctrl, &base->lincr1); /* end init mode */ 119 120 return 0; 121 } 122 123 struct linflex_serial_platdata { 124 struct linflex_fsl *base_addr; 125 u8 port_id; /* do we need this? */ 126 }; 127 128 struct linflex_serial_priv { 129 struct linflex_fsl *lfuart; 130 }; 131 132 int linflex_serial_setbrg(struct udevice *dev, int baudrate) 133 { 134 struct linflex_serial_priv *priv = dev_get_priv(dev); 135 136 _linflex_serial_setbrg(priv->lfuart, baudrate); 137 138 return 0; 139 } 140 141 static int linflex_serial_getc(struct udevice *dev) 142 { 143 struct linflex_serial_priv *priv = dev_get_priv(dev); 144 145 return _linflex_serial_getc(priv->lfuart); 146 } 147 148 static int linflex_serial_putc(struct udevice *dev, const char ch) 149 { 150 151 struct linflex_serial_priv *priv = dev_get_priv(dev); 152 153 return _linflex_serial_putc(priv->lfuart, ch); 154 } 155 156 static int linflex_serial_pending(struct udevice *dev, bool input) 157 { 158 struct linflex_serial_priv *priv = dev_get_priv(dev); 159 uint32_t uartsr = __raw_readl(&priv->lfuart->uartsr); 160 161 if (input) 162 return ((uartsr & UARTSR_DRF) && (uartsr & UARTSR_RMB)) ? 1 : 0; 163 else 164 return uartsr & UARTSR_DTF ? 0 : 1; 165 } 166 167 static void linflex_serial_init_internal(struct linflex_fsl *lfuart) 168 { 169 _linflex_serial_init(lfuart); 170 _linflex_serial_setbrg(lfuart, CONFIG_BAUDRATE); 171 return; 172 } 173 174 static int linflex_serial_probe(struct udevice *dev) 175 { 176 struct linflex_serial_platdata *plat = dev->platdata; 177 struct linflex_serial_priv *priv = dev_get_priv(dev); 178 179 priv->lfuart = (struct linflex_fsl *)plat->base_addr; 180 linflex_serial_init_internal(priv->lfuart); 181 182 return 0; 183 } 184 185 static const struct dm_serial_ops linflex_serial_ops = { 186 .putc = linflex_serial_putc, 187 .pending = linflex_serial_pending, 188 .getc = linflex_serial_getc, 189 .setbrg = linflex_serial_setbrg, 190 }; 191 192 U_BOOT_DRIVER(serial_linflex) = { 193 .name = "serial_linflex", 194 .id = UCLASS_SERIAL, 195 .probe = linflex_serial_probe, 196 .ops = &linflex_serial_ops, 197 .flags = DM_FLAG_PRE_RELOC, 198 .priv_auto_alloc_size = sizeof(struct linflex_serial_priv), 199 }; 200 201 #ifdef CONFIG_DEBUG_UART_LINFLEXUART 202 203 #include <debug_uart.h> 204 205 206 static inline void _debug_uart_init(void) 207 { 208 struct linflex_fsl *base = (struct linflex_fsl *)CONFIG_DEBUG_UART_BASE; 209 210 linflex_serial_init_internal(base); 211 } 212 213 static inline void _debug_uart_putc(int ch) 214 { 215 struct linflex_fsl *base = (struct linflex_fsl *)CONFIG_DEBUG_UART_BASE; 216 217 /* XXX: Is this OK? Should this use the non-DM version? */ 218 _linflex_serial_putc(base, ch); 219 } 220 221 DEBUG_UART_FUNCS 222 223 #endif /* CONFIG_DEBUG_UART_LINFLEXUART */ 224