aboutsummaryrefslogtreecommitdiff
path: root/drivers/serial/serial_mpc8xx.c
blob: 26a8085a6917deda2b8bb8dad159d4f9aa33c3b8 (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
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
/*
 * (C) Copyright 2000
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * SPDX-License-Identifier:	GPL-2.0+
 */

#include <common.h>
#include <commproc.h>
#include <command.h>
#include <serial.h>
#include <watchdog.h>
#include <linux/compiler.h>

DECLARE_GLOBAL_DATA_PTR;

#if defined(CONFIG_8xx_CONS_SMC1)	/* Console on SMC1 */
#define	SMC_INDEX	0
#define PROFF_SMC	PROFF_SMC1
#define CPM_CR_CH_SMC	CPM_CR_CH_SMC1
#define IOPINS		0xc0

#elif defined(CONFIG_8xx_CONS_SMC2)	/* Console on SMC2 */
#define SMC_INDEX	1
#define PROFF_SMC	PROFF_SMC2
#define CPM_CR_CH_SMC	CPM_CR_CH_SMC2
#define IOPINS		0xc00

#endif /* CONFIG_8xx_CONS_SMCx */

struct serialbuffer {
	cbd_t	rxbd;		/* Rx BD */
	cbd_t	txbd;		/* Tx BD */
	uint	rxindex;	/* index for next character to read */
	uchar	rxbuf[CONFIG_SYS_SMC_RXBUFLEN];/* rx buffers */
	uchar	txbuf;	/* tx buffers */
};

static void serial_setdivisor(cpm8xx_t __iomem *cp)
{
	int divisor = (gd->cpu_clk + 8 * gd->baudrate) / 16 / gd->baudrate;

	if (divisor / 16 > 0x1000) {
		/* bad divisor, assume 50MHz clock and 9600 baud */
		divisor = (50 * 1000 * 1000 + 8 * 9600) / 16 / 9600;
	}

	divisor /= CONFIG_SYS_BRGCLK_PRESCALE;

	if (divisor <= 0x1000)
		out_be32(&cp->cp_brgc1, ((divisor - 1) << 1) | CPM_BRG_EN);
	else
		out_be32(&cp->cp_brgc1, ((divisor / 16 - 1) << 1) | CPM_BRG_EN |
			 CPM_BRG_DIV16);
}

/*
 * Minimal serial functions needed to use one of the SMC ports
 * as serial console interface.
 */

static void smc_setbrg(void)
{
	immap_t __iomem *im = (immap_t __iomem *)CONFIG_SYS_IMMR;
	cpm8xx_t __iomem *cp = &(im->im_cpm);

	/* Set up the baud rate generator.
	 * See 8xx_io/commproc.c for details.
	 *
	 * Wire BRG1 to SMCx
	 */

	out_be32(&cp->cp_simode, 0);

	serial_setdivisor(cp);
}

static int smc_init(void)
{
	immap_t __iomem *im = (immap_t __iomem *)CONFIG_SYS_IMMR;
	smc_t __iomem *sp;
	smc_uart_t __iomem *up;
	cpm8xx_t __iomem *cp = &(im->im_cpm);
	struct serialbuffer __iomem *rtx;

	/* initialize pointers to SMC */

	sp = cp->cp_smc + SMC_INDEX;
	up = (smc_uart_t __iomem *)&cp->cp_dparam[PROFF_SMC];
	/* Disable relocation */
	out_be16(&up->smc_rpbase, 0);

	/* Disable transmitter/receiver. */
	clrbits_be16(&sp->smc_smcmr, SMCMR_REN | SMCMR_TEN);

	/* Enable SDMA. */
	out_be32(&im->im_siu_conf.sc_sdcr, 1);

	/* clear error conditions */
	out_8(&im->im_sdma.sdma_sdsr, CONFIG_SYS_SDSR);

	/* clear SDMA interrupt mask */
	out_8(&im->im_sdma.sdma_sdmr, CONFIG_SYS_SDMR);

	/* Use Port B for SMCx instead of other functions. */
	setbits_be32(&cp->cp_pbpar, IOPINS);
	clrbits_be32(&cp->cp_pbdir, IOPINS);
	clrbits_be16(&cp->cp_pbodr, IOPINS);

	/* Set the physical address of the host memory buffers in
	 * the buffer descriptors.
	 */
	rtx = (struct serialbuffer __iomem *)&cp->cp_dpmem[CPM_SERIAL_BASE];
	/* Allocate space for two buffer descriptors in the DP ram.
	 * For now, this address seems OK, but it may have to
	 * change with newer versions of the firmware.
	 * damm: allocating space after the two buffers for rx/tx data
	 */

	out_be32(&rtx->rxbd.cbd_bufaddr, (__force uint)&rtx->rxbuf);
	out_be16(&rtx->rxbd.cbd_sc, 0);

	out_be32(&rtx->txbd.cbd_bufaddr, (__force uint)&rtx->txbuf);
	out_be16(&rtx->txbd.cbd_sc, 0);

	/* Set up the uart parameters in the parameter ram. */
	out_be16(&up->smc_rbase, CPM_SERIAL_BASE);
	out_be16(&up->smc_tbase, CPM_SERIAL_BASE + sizeof(cbd_t));
	out_8(&up->smc_rfcr, SMC_EB);
	out_8(&up->smc_tfcr, SMC_EB);

	/* Set UART mode, 8 bit, no parity, one stop.
	 * Enable receive and transmit.
	 */
	out_be16(&sp->smc_smcmr, smcr_mk_clen(9) | SMCMR_SM_UART);

	/* Mask all interrupts and remove anything pending.
	*/
	out_8(&sp->smc_smcm, 0);
	out_8(&sp->smc_smce, 0xff);

	/* Set up the baud rate generator */
	smc_setbrg();

	/* Make the first buffer the only buffer. */
	setbits_be16(&rtx->txbd.cbd_sc, BD_SC_WRAP);
	setbits_be16(&rtx->rxbd.cbd_sc, BD_SC_EMPTY | BD_SC_WRAP);

	/* single/multi character receive. */
	out_be16(&up->smc_mrblr, CONFIG_SYS_SMC_RXBUFLEN);
	out_be16(&up->smc_maxidl, CONFIG_SYS_MAXIDLE);
	out_be32(&rtx->rxindex, 0);

	/* Initialize Tx/Rx parameters.	*/
	while (in_be16(&cp->cp_cpcr) & CPM_CR_FLG)	/* wait if cp is busy */
		;

	out_be16(&cp->cp_cpcr,
		 mk_cr_cmd(CPM_CR_CH_SMC, CPM_CR_INIT_TRX) | CPM_CR_FLG);

	while (in_be16(&cp->cp_cpcr) & CPM_CR_FLG)	/* wait if cp is busy */
		;

	/* Enable transmitter/receiver.	*/
	setbits_be16(&sp->smc_smcmr, SMCMR_REN | SMCMR_TEN);

	return 0;
}

static void smc_putc(const char c)
{
	immap_t	__iomem *im = (immap_t __iomem *)CONFIG_SYS_IMMR;
	cpm8xx_t	__iomem *cpmp = &(im->im_cpm);
	struct serialbuffer	__iomem *rtx;

	if (c == '\n')
		smc_putc('\r');

	rtx = (struct serialbuffer __iomem *)&cpmp->cp_dpmem[CPM_SERIAL_BASE];

	/* Wait for last character to go. */
	out_8(&rtx->txbuf, c);
	out_be16(&rtx->txbd.cbd_datlen, 1);
	setbits_be16(&rtx->txbd.cbd_sc, BD_SC_READY);

	while (in_be16(&rtx->txbd.cbd_sc) & BD_SC_READY)
		WATCHDOG_RESET();
}

static void smc_puts(const char *s)
{
	while (*s)
		smc_putc(*s++);
}

static int smc_getc(void)
{
	immap_t	__iomem *im = (immap_t __iomem *)CONFIG_SYS_IMMR;
	cpm8xx_t	__iomem *cpmp = &(im->im_cpm);
	struct serialbuffer	__iomem *rtx;
	unsigned char  c;
	uint rxindex;

	rtx = (struct serialbuffer __iomem *)&cpmp->cp_dpmem[CPM_SERIAL_BASE];

	/* Wait for character to show up. */
	while (in_be16(&rtx->rxbd.cbd_sc) & BD_SC_EMPTY)
		WATCHDOG_RESET();

	/* the characters are read one by one,
	 * use the rxindex to know the next char to deliver
	 */
	rxindex = in_be32(&rtx->rxindex);
	c = in_8(rtx->rxbuf + rxindex);
	rxindex++;

	/* check if all char are readout, then make prepare for next receive */
	if (rxindex >= in_be16(&rtx->rxbd.cbd_datlen)) {
		rxindex = 0;
		setbits_be16(&rtx->rxbd.cbd_sc, BD_SC_EMPTY);
	}
	out_be32(&rtx->rxindex, rxindex);
	return c;
}

static int smc_tstc(void)
{
	immap_t	__iomem *im = (immap_t __iomem *)CONFIG_SYS_IMMR;
	cpm8xx_t	__iomem *cpmp = &(im->im_cpm);
	struct serialbuffer	__iomem *rtx;

	rtx = (struct serialbuffer __iomem *)&cpmp->cp_dpmem[CPM_SERIAL_BASE];

	return !(in_be16(&rtx->rxbd.cbd_sc) & BD_SC_EMPTY);
}

struct serial_device serial_smc_device = {
	.name	= "serial_smc",
	.start	= smc_init,
	.stop	= NULL,
	.setbrg	= smc_setbrg,
	.getc	= smc_getc,
	.tstc	= smc_tstc,
	.putc	= smc_putc,
	.puts	= smc_puts,
};

__weak struct serial_device *default_serial_console(void)
{
	return &serial_smc_device;
}

void mpc8xx_serial_initialize(void)
{
	serial_register(&serial_smc_device);
}