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