aboutsummaryrefslogtreecommitdiff
path: root/drivers/serial/serial_linflexuart.c
blob: 4f8867ab7be7dc7f814e4f857a56d2ebc3902cb4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
// SPDX-License-Identifier: GPL-2.0+
/*
 * (C) Copyright 2013-2016 Freescale Semiconductor, Inc.
 */

#include <common.h>
#include <dm.h>
#include <errno.h>
#include <watchdog.h>
#include <asm/io.h>
#include <serial.h>
#include <linux/compiler.h>
#include <asm/arch/imx-regs.h>
#include <asm/arch/clock.h>

#define US1_TDRE            (1 << 7)
#define US1_RDRF            (1 << 5)
#define UC2_TE              (1 << 3)
#define LINCR1_INIT         (1 << 0)
#define LINCR1_MME          (1 << 4)
#define LINCR1_BF           (1 << 7)
#define LINSR_LINS_INITMODE (0x00001000)
#define LINSR_LINS_MASK     (0x0000F000)
#define UARTCR_UART         (1 << 0)
#define UARTCR_WL0          (1 << 1)
#define UARTCR_PCE          (1 << 2)
#define UARTCR_PC0          (1 << 3)
#define UARTCR_TXEN         (1 << 4)
#define UARTCR_RXEN         (1 << 5)
#define UARTCR_PC1          (1 << 6)
#define UARTSR_DTF          (1 << 1)
#define UARTSR_DRF          (1 << 2)
#define UARTSR_RMB          (1 << 9)

DECLARE_GLOBAL_DATA_PTR;

static void _linflex_serial_setbrg(struct linflex_fsl *base, int baudrate)
{
	u32 clk = mxc_get_clock(MXC_UART_CLK);
	u32 ibr, fbr;

	if (!baudrate)
		baudrate = CONFIG_BAUDRATE;

	ibr = (u32) (clk / (16 * gd->baudrate));
	fbr = (u32) (clk % (16 * gd->baudrate)) * 16;

	__raw_writel(ibr, &base->linibrr);
	__raw_writel(fbr, &base->linfbrr);
}

static int _linflex_serial_getc(struct linflex_fsl *base)
{
	char c;

	if (!(__raw_readb(&base->uartsr) & UARTSR_DRF))
		return -EAGAIN;

	if (!(__raw_readl(&base->uartsr) & UARTSR_RMB))
		return -EAGAIN;

	c = __raw_readl(&base->bdrm);
	__raw_writeb((__raw_readb(&base->uartsr) | (UARTSR_DRF | UARTSR_RMB)),
		     &base->uartsr);
	return c;
}

static int _linflex_serial_putc(struct linflex_fsl *base, const char c)
{
	__raw_writeb(c, &base->bdrl);


	if (!(__raw_readb(&base->uartsr) & UARTSR_DTF))
		return -EAGAIN;

	__raw_writeb((__raw_readb(&base->uartsr) | UARTSR_DTF), &base->uartsr);

	return 0;
}

/*
 * Initialise the serial port with the given baudrate. The settings
 * are always 8 data bits, no parity, 1 stop bit, no start bits.
 */
static int _linflex_serial_init(struct linflex_fsl *base)
{
	volatile u32 ctrl;

	/* set the Linflex in master mode amd activate by-pass filter */
	ctrl = LINCR1_BF | LINCR1_MME;
	__raw_writel(ctrl, &base->lincr1);

	/* init mode */
	ctrl |= LINCR1_INIT;
	__raw_writel(ctrl, &base->lincr1);

	/* waiting for init mode entry - TODO: add a timeout */
	while ((__raw_readl(&base->linsr) & LINSR_LINS_MASK) !=
	       LINSR_LINS_INITMODE);

	/* set UART bit to allow writing other bits */
	__raw_writel(UARTCR_UART, &base->uartcr);

	/* provide data bits, parity, stop bit, etc */
	serial_setbrg();

	/* 8 bit data, no parity, Tx and Rx enabled, UART mode */
	__raw_writel(UARTCR_PC1 | UARTCR_RXEN | UARTCR_TXEN | UARTCR_PC0
		     | UARTCR_WL0 | UARTCR_UART, &base->uartcr);

	ctrl = __raw_readl(&base->lincr1);
	ctrl &= ~LINCR1_INIT;
	__raw_writel(ctrl, &base->lincr1);	/* end init mode */

	return 0;
}

struct linflex_serial_platdata {
	struct linflex_fsl *base_addr;
	u8 port_id; /* do we need this? */
};

struct linflex_serial_priv {
	struct linflex_fsl *lfuart;
};

int linflex_serial_setbrg(struct udevice *dev, int baudrate)
{
	struct linflex_serial_priv *priv = dev_get_priv(dev);

	_linflex_serial_setbrg(priv->lfuart, baudrate);

	return 0;
}

static int linflex_serial_getc(struct udevice *dev)
{
	struct linflex_serial_priv *priv = dev_get_priv(dev);

	return _linflex_serial_getc(priv->lfuart);
}

static int linflex_serial_putc(struct udevice *dev, const char ch)
{

	struct linflex_serial_priv *priv = dev_get_priv(dev);

	return _linflex_serial_putc(priv->lfuart, ch);
}

static int linflex_serial_pending(struct udevice *dev, bool input)
{
	struct linflex_serial_priv *priv = dev_get_priv(dev);
	uint32_t uartsr = __raw_readl(&priv->lfuart->uartsr);

	if (input)
		return ((uartsr & UARTSR_DRF) && (uartsr & UARTSR_RMB)) ? 1 : 0;
	else
		return uartsr & UARTSR_DTF ? 0 : 1;
}

static void linflex_serial_init_internal(struct linflex_fsl *lfuart)
{
	_linflex_serial_init(lfuart);
	_linflex_serial_setbrg(lfuart, CONFIG_BAUDRATE);
	return;
}

static int linflex_serial_probe(struct udevice *dev)
{
	struct linflex_serial_platdata *plat = dev->plat;
	struct linflex_serial_priv *priv = dev_get_priv(dev);

	priv->lfuart = (struct linflex_fsl *)plat->base_addr;
	linflex_serial_init_internal(priv->lfuart);

	return 0;
}

static const struct dm_serial_ops linflex_serial_ops = {
	.putc = linflex_serial_putc,
	.pending = linflex_serial_pending,
	.getc = linflex_serial_getc,
	.setbrg = linflex_serial_setbrg,
};

U_BOOT_DRIVER(serial_linflex) = {
	.name	= "serial_linflex",
	.id	= UCLASS_SERIAL,
	.probe = linflex_serial_probe,
	.ops	= &linflex_serial_ops,
	.flags = DM_FLAG_PRE_RELOC,
	.priv_auto	= sizeof(struct linflex_serial_priv),
};

#ifdef CONFIG_DEBUG_UART_LINFLEXUART

#include <debug_uart.h>


static inline void _debug_uart_init(void)
{
	struct linflex_fsl *base = (struct linflex_fsl *)CONFIG_DEBUG_UART_BASE;

	linflex_serial_init_internal(base);
}

static inline void _debug_uart_putc(int ch)
{
	struct linflex_fsl *base = (struct linflex_fsl *)CONFIG_DEBUG_UART_BASE;

	/* XXX: Is this OK? Should this use the non-DM version? */
	_linflex_serial_putc(base, ch);
}

DEBUG_UART_FUNCS

#endif /* CONFIG_DEBUG_UART_LINFLEXUART */