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