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Committer: Michael Beasley <mike@snafu.setup>
[mikesnafu-overlay.git] / arch / ppc / boot / simple / mv64x60_tty.c
blob8a735787a6e9932798c3776acd3de53d8451ac8e
1 /*
2 * Bootloader version of the embedded MPSC/UART driver for the Marvell 64x60.
3 * Note: Due to a GT64260A erratum, DMA will be used for UART input (via SDMA).
4 *
5 * Author: Mark A. Greer <mgreer@mvista.com>
6 *
7 * 2001 (c) MontaVista Software, Inc. This file is licensed under
8 * the terms of the GNU General Public License version 2. This program
9 * is licensed "as is" without any warranty of any kind, whether express
10 * or implied.
11 */
12
13 /* This code assumes that the data cache has been disabled (L1, L2, L3). */
14
15 #include <linux/types.h>
16 #include <linux/serial_reg.h>
17 #include <asm/serial.h>
18 #include <asm/io.h>
19 #include <asm/mv64x60_defs.h>
20 #include <mpsc_defs.h>
21
22 #ifdef CONFIG_EV64360
23 #include <platforms/ev64360.h>
24 u32 mv64x60_console_baud = EV64360_DEFAULT_BAUD;
25 u32 mv64x60_mpsc_clk_src = EV64360_MPSC_CLK_SRC; /* TCLK */
26 u32 mv64x60_mpsc_clk_freq = EV64360_MPSC_CLK_FREQ;
27 #else
28 u32 mv64x60_console_baud = 9600;
29 u32 mv64x60_mpsc_clk_src = 8; /* TCLK */
30 u32 mv64x60_mpsc_clk_freq = 100000000;
31 #endif
32
33 extern void udelay(long);
34 static void stop_dma(int chan);
35
36 static void __iomem *mv64x60_base = (void __iomem *)CONFIG_MV64X60_NEW_BASE;
37
38 struct sdma_regs {
39 u32 sdc;
40 u32 sdcm;
41 u32 rx_desc;
42 u32 rx_buf_ptr;
43 u32 scrdp;
44 u32 tx_desc;
45 u32 sctdp;
46 u32 sftdp;
47 };
48
49 static struct sdma_regs sdma_regs[2];
50
51 #define SDMA_REGS_INIT(s, reg_base) { \
52 (s)->sdc = (reg_base) + SDMA_SDC; \
53 (s)->sdcm = (reg_base) + SDMA_SDCM; \
54 (s)->rx_desc = (reg_base) + SDMA_RX_DESC; \
55 (s)->rx_buf_ptr = (reg_base) + SDMA_RX_BUF_PTR; \
56 (s)->scrdp = (reg_base) + SDMA_SCRDP; \
57 (s)->tx_desc = (reg_base) + SDMA_TX_DESC; \
58 (s)->sctdp = (reg_base) + SDMA_SCTDP; \
59 (s)->sftdp = (reg_base) + SDMA_SFTDP; \
60 }
61
62 static u32 mpsc_base[2] = { MV64x60_MPSC_0_OFFSET, MV64x60_MPSC_1_OFFSET };
63
64 struct mv64x60_rx_desc {
65 u16 bufsize;
66 u16 bytecnt;
67 u32 cmd_stat;
68 u32 next_desc_ptr;
69 u32 buffer;
70 };
71
72 struct mv64x60_tx_desc {
73 u16 bytecnt;
74 u16 shadow;
75 u32 cmd_stat;
76 u32 next_desc_ptr;
77 u32 buffer;
78 };
79
80 #define MAX_RESET_WAIT 10000
81 #define MAX_TX_WAIT 10000
82
83 #define RX_NUM_DESC 2
84 #define TX_NUM_DESC 2
85
86 #define RX_BUF_SIZE 32
87 #define TX_BUF_SIZE 32
88
89 static struct mv64x60_rx_desc rd[2][RX_NUM_DESC] __attribute__ ((aligned(32)));
90 static struct mv64x60_tx_desc td[2][TX_NUM_DESC] __attribute__ ((aligned(32)));
91
92 static char rx_buf[2][RX_NUM_DESC * RX_BUF_SIZE] __attribute__ ((aligned(32)));
93 static char tx_buf[2][TX_NUM_DESC * TX_BUF_SIZE] __attribute__ ((aligned(32)));
94
95 static int cur_rd[2] = { 0, 0 };
96 static int cur_td[2] = { 0, 0 };
97
98 static char chan_initialized[2] = { 0, 0 };
99
100
101 #define RX_INIT_RDP(rdp) { \
102 (rdp)->bufsize = 2; \
103 (rdp)->bytecnt = 0; \
104 (rdp)->cmd_stat = SDMA_DESC_CMDSTAT_L | SDMA_DESC_CMDSTAT_F | \
105 SDMA_DESC_CMDSTAT_O; \
106 }
107
108 #ifdef CONFIG_MV64360
109 static u32 cpu2mem_tab[MV64x60_CPU2MEM_WINDOWS][2] = {
110 { MV64x60_CPU2MEM_0_BASE, MV64x60_CPU2MEM_0_SIZE },
111 { MV64x60_CPU2MEM_1_BASE, MV64x60_CPU2MEM_1_SIZE },
112 { MV64x60_CPU2MEM_2_BASE, MV64x60_CPU2MEM_2_SIZE },
113 { MV64x60_CPU2MEM_3_BASE, MV64x60_CPU2MEM_3_SIZE }
114 };
115
116 static u32 com2mem_tab[MV64x60_CPU2MEM_WINDOWS][2] = {
117 { MV64360_MPSC2MEM_0_BASE, MV64360_MPSC2MEM_0_SIZE },
118 { MV64360_MPSC2MEM_1_BASE, MV64360_MPSC2MEM_1_SIZE },
119 { MV64360_MPSC2MEM_2_BASE, MV64360_MPSC2MEM_2_SIZE },
120 { MV64360_MPSC2MEM_3_BASE, MV64360_MPSC2MEM_3_SIZE }
121 };
122
123 static u32 dram_selects[MV64x60_CPU2MEM_WINDOWS] = { 0xe, 0xd, 0xb, 0x7 };
124 #endif
125
126 unsigned long
127 serial_init(int chan, void *ignored)
128 {
129 u32 mpsc_routing_base, sdma_base, brg_bcr, cdv;
130 int i;
131
132 chan = (chan == 1); /* default to chan 0 if anything but 1 */
133
134 if (chan_initialized[chan])
135 return chan;
136
137 chan_initialized[chan] = 1;
138
139 if (chan == 0) {
140 sdma_base = MV64x60_SDMA_0_OFFSET;
141 brg_bcr = MV64x60_BRG_0_OFFSET + BRG_BCR;
142 SDMA_REGS_INIT(&sdma_regs[0], MV64x60_SDMA_0_OFFSET);
143 } else {
144 sdma_base = MV64x60_SDMA_1_OFFSET;
145 brg_bcr = MV64x60_BRG_1_OFFSET + BRG_BCR;
146 SDMA_REGS_INIT(&sdma_regs[0], MV64x60_SDMA_1_OFFSET);
147 }
148
149 mpsc_routing_base = MV64x60_MPSC_ROUTING_OFFSET;
150
151 stop_dma(chan);
152
153 /* Set up ring buffers */
154 for (i=0; i<RX_NUM_DESC; i++) {
155 RX_INIT_RDP(&rd[chan][i]);
156 rd[chan][i].buffer = (u32)&rx_buf[chan][i * RX_BUF_SIZE];
157 rd[chan][i].next_desc_ptr = (u32)&rd[chan][i+1];
158 }
159 rd[chan][RX_NUM_DESC - 1].next_desc_ptr = (u32)&rd[chan][0];
160
161 for (i=0; i<TX_NUM_DESC; i++) {
162 td[chan][i].bytecnt = 0;
163 td[chan][i].shadow = 0;
164 td[chan][i].buffer = (u32)&tx_buf[chan][i * TX_BUF_SIZE];
165 td[chan][i].cmd_stat = SDMA_DESC_CMDSTAT_F|SDMA_DESC_CMDSTAT_L;
166 td[chan][i].next_desc_ptr = (u32)&td[chan][i+1];
167 }
168 td[chan][TX_NUM_DESC - 1].next_desc_ptr = (u32)&td[chan][0];
169
170 /* Set MPSC Routing */
171 out_le32(mv64x60_base + mpsc_routing_base + MPSC_MRR, 0x3ffffe38);
172
173 #ifdef CONFIG_GT64260
174 out_le32(mv64x60_base + GT64260_MPP_SERIAL_PORTS_MULTIPLEX, 0x00001102);
175 #else /* Must be MV64360 or MV64460 */
176 {
177 u32 enables, prot_bits, v;
178
179 /* Set up comm unit to memory mapping windows */
180 /* Note: Assumes MV64x60_CPU2MEM_WINDOWS == 4 */
181
182 enables = in_le32(mv64x60_base + MV64360_CPU_BAR_ENABLE) & 0xf;
183 prot_bits = 0;
184
185 for (i=0; i<MV64x60_CPU2MEM_WINDOWS; i++) {
186 if (!(enables & (1 << i))) {
187 v = in_le32(mv64x60_base + cpu2mem_tab[i][0]);
188 v = ((v & 0xffff) << 16) | (dram_selects[i] << 8);
189 out_le32(mv64x60_base + com2mem_tab[i][0], v);
190
191 v = in_le32(mv64x60_base + cpu2mem_tab[i][1]);
192 v = (v & 0xffff) << 16;
193 out_le32(mv64x60_base + com2mem_tab[i][1], v);
194
195 prot_bits |= (0x3 << (i << 1)); /* r/w access */
196 }
197 }
198
199 out_le32(mv64x60_base + MV64360_MPSC_0_REMAP, 0);
200 out_le32(mv64x60_base + MV64360_MPSC_1_REMAP, 0);
201 out_le32(mv64x60_base + MV64360_MPSC2MEM_ACC_PROT_0, prot_bits);
202 out_le32(mv64x60_base + MV64360_MPSC2MEM_ACC_PROT_1, prot_bits);
203 out_le32(mv64x60_base + MV64360_MPSC2MEM_BAR_ENABLE, enables);
204 }
205 #endif
206
207 /* MPSC 0/1 Rx & Tx get clocks BRG0/1 */
208 out_le32(mv64x60_base + mpsc_routing_base + MPSC_RCRR, 0x00000100);
209 out_le32(mv64x60_base + mpsc_routing_base + MPSC_TCRR, 0x00000100);
210
211 /* clear pending interrupts */
212 out_le32(mv64x60_base + MV64x60_SDMA_INTR_OFFSET + SDMA_INTR_MASK, 0);
213
214 out_le32(mv64x60_base + SDMA_SCRDP + sdma_base, (int)&rd[chan][0]);
215 out_le32(mv64x60_base + SDMA_SCTDP + sdma_base,
216 (int)&td[chan][TX_NUM_DESC - 1]);
217 out_le32(mv64x60_base + SDMA_SFTDP + sdma_base,
218 (int)&td[chan][TX_NUM_DESC - 1]);
219
220 out_le32(mv64x60_base + SDMA_SDC + sdma_base,
221 SDMA_SDC_RFT | SDMA_SDC_SFM | SDMA_SDC_BLMR | SDMA_SDC_BLMT |
222 (3 << 12));
223
224 cdv = ((mv64x60_mpsc_clk_freq/(32*mv64x60_console_baud))-1);
225 out_le32(mv64x60_base + brg_bcr,
226 ((mv64x60_mpsc_clk_src << 18) | (1 << 16) | cdv));
227
228 /* Put MPSC into UART mode, no null modem, 16x clock mode */
229 out_le32(mv64x60_base + MPSC_MMCRL + mpsc_base[chan], 0x000004c4);
230 out_le32(mv64x60_base + MPSC_MMCRH + mpsc_base[chan], 0x04400400);
231
232 out_le32(mv64x60_base + MPSC_CHR_1 + mpsc_base[chan], 0);
233 out_le32(mv64x60_base + MPSC_CHR_9 + mpsc_base[chan], 0);
234 out_le32(mv64x60_base + MPSC_CHR_10 + mpsc_base[chan], 0);
235 out_le32(mv64x60_base + MPSC_CHR_3 + mpsc_base[chan], 4);
236 out_le32(mv64x60_base + MPSC_CHR_4 + mpsc_base[chan], 0);
237 out_le32(mv64x60_base + MPSC_CHR_5 + mpsc_base[chan], 0);
238 out_le32(mv64x60_base + MPSC_CHR_6 + mpsc_base[chan], 0);
239 out_le32(mv64x60_base + MPSC_CHR_7 + mpsc_base[chan], 0);
240 out_le32(mv64x60_base + MPSC_CHR_8 + mpsc_base[chan], 0);
241
242 /* 8 data bits, 1 stop bit */
243 out_le32(mv64x60_base + MPSC_MPCR + mpsc_base[chan], (3 << 12));
244 out_le32(mv64x60_base + SDMA_SDCM + sdma_base, SDMA_SDCM_ERD);
245 out_le32(mv64x60_base + MPSC_CHR_2 + mpsc_base[chan], MPSC_CHR_2_EH);
246
247 udelay(100);
248
249 return chan;
250 }
251
252 static void
253 stop_dma(int chan)
254 {
255 int i;
256
257 /* Abort MPSC Rx (aborting Tx messes things up) */
258 out_le32(mv64x60_base + MPSC_CHR_2 + mpsc_base[chan], MPSC_CHR_2_RA);
259
260 /* Abort SDMA Rx, Tx */
261 out_le32(mv64x60_base + sdma_regs[chan].sdcm,
262 SDMA_SDCM_AR | SDMA_SDCM_STD);
263
264 for (i=0; i<MAX_RESET_WAIT; i++) {
265 if ((in_le32(mv64x60_base + sdma_regs[chan].sdcm) &
266 (SDMA_SDCM_AR | SDMA_SDCM_AT)) == 0)
267 break;
268
269 udelay(100);
270 }
271 }
272
273 static int
274 wait_for_ownership(int chan)
275 {
276 int i;
277
278 for (i=0; i<MAX_TX_WAIT; i++) {
279 if ((in_le32(mv64x60_base + sdma_regs[chan].sdcm) &
280 SDMA_SDCM_TXD) == 0)
281 break;
282
283 udelay(1000);
284 }
285
286 return (i < MAX_TX_WAIT);
287 }
288
289 void
290 serial_putc(unsigned long com_port, unsigned char c)
291 {
292 struct mv64x60_tx_desc *tdp;
293
294 if (wait_for_ownership(com_port) == 0)
295 return;
296
297 tdp = &td[com_port][cur_td[com_port]];
298 if (++cur_td[com_port] >= TX_NUM_DESC)
299 cur_td[com_port] = 0;
300
301 *(unchar *)(tdp->buffer ^ 7) = c;
302 tdp->bytecnt = 1;
303 tdp->shadow = 1;
304 tdp->cmd_stat = SDMA_DESC_CMDSTAT_L | SDMA_DESC_CMDSTAT_F |
305 SDMA_DESC_CMDSTAT_O;
306
307 out_le32(mv64x60_base + sdma_regs[com_port].sctdp, (int)tdp);
308 out_le32(mv64x60_base + sdma_regs[com_port].sftdp, (int)tdp);
309 out_le32(mv64x60_base + sdma_regs[com_port].sdcm,
310 in_le32(mv64x60_base + sdma_regs[com_port].sdcm) |
311 SDMA_SDCM_TXD);
312 }
313
314 unsigned char
315 serial_getc(unsigned long com_port)
316 {
317 struct mv64x60_rx_desc *rdp;
318 unchar c = '\0';
319
320 rdp = &rd[com_port][cur_rd[com_port]];
321
322 if ((rdp->cmd_stat & (SDMA_DESC_CMDSTAT_O|SDMA_DESC_CMDSTAT_ES)) == 0) {
323 c = *(unchar *)(rdp->buffer ^ 7);
324 RX_INIT_RDP(rdp);
325 if (++cur_rd[com_port] >= RX_NUM_DESC)
326 cur_rd[com_port] = 0;
327 }
328
329 return c;
330 }
331
332 int
333 serial_tstc(unsigned long com_port)
334 {
335 struct mv64x60_rx_desc *rdp;
336 int loop_count = 0;
337 int rc = 0;
338
339 rdp = &rd[com_port][cur_rd[com_port]];
340
341 /* Go through rcv descs until empty looking for one with data (no error)*/
342 while (((rdp->cmd_stat & SDMA_DESC_CMDSTAT_O) == 0) &&
343 (loop_count++ < RX_NUM_DESC)) {
344
345 /* If there was an error, reinit the desc & continue */
346 if ((rdp->cmd_stat & SDMA_DESC_CMDSTAT_ES) != 0) {
347 RX_INIT_RDP(rdp);
348 if (++cur_rd[com_port] >= RX_NUM_DESC)
349 cur_rd[com_port] = 0;
350 rdp = (struct mv64x60_rx_desc *)rdp->next_desc_ptr;
351 } else {
352 rc = 1;
353 break;
354 }
355 }
356
357 return rc;
358 }
359
360 void
361 serial_close(unsigned long com_port)
362 {
363 stop_dma(com_port);
364 }
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