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
36 DECLARE_GLOBAL_DATA_PTR;
37
_linflex_serial_setbrg(struct linflex_fsl * base,int baudrate)38 static 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
_linflex_serial_getc(struct linflex_fsl * base)53 static 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
_linflex_serial_putc(struct linflex_fsl * base,const char c)69 static 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 */
_linflex_serial_init(struct linflex_fsl * base)86 static 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
119 struct linflex_serial_plat {
120 struct linflex_fsl *base_addr;
121 u8 port_id; /* do we need this? */
122 };
123
124 struct linflex_serial_priv {
125 struct linflex_fsl *lfuart;
126 };
127
linflex_serial_setbrg(struct udevice * dev,int baudrate)128 int 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
linflex_serial_getc(struct udevice * dev)137 static 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
linflex_serial_putc(struct udevice * dev,const char ch)144 static 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
linflex_serial_pending(struct udevice * dev,bool input)152 static 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
linflex_serial_init_internal(struct linflex_fsl * lfuart)163 static 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
linflex_serial_probe(struct udevice * dev)170 static 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
181 static 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
188 U_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
_debug_uart_init(void)202 static inline void _debug_uart_init(void)
203 {
204 struct linflex_fsl *base = (struct linflex_fsl *)CONFIG_DEBUG_UART_BASE;
205
206 linflex_serial_init_internal(base);
207 }
208
_debug_uart_putc(int ch)209 static inline void _debug_uart_putc(int ch)
210 {
211 struct linflex_fsl *base = (struct linflex_fsl *)CONFIG_DEBUG_UART_BASE;
212
213 /* XXX: Is this OK? Should this use the non-DM version? */
214 _linflex_serial_putc(base, ch);
215 }
216
217 DEBUG_UART_FUNCS
218
219 #endif /* CONFIG_DEBUG_UART_LINFLEXUART */
220