1 /*
2 * General Purpose functions for the global management of the
3 * Communication Processor Module.
4 *
5 * Copyright (c) 2000 Michael Leslie <mleslie@lineo.com>
6 * Copyright (c) 1997 Dan Malek (dmalek@jlc.net)
7 *
8 * In addition to the individual control of the communication
9 * channels, there are a few functions that globally affect the
10 * communication processor.
11 *
12 * Buffer descriptors must be allocated from the dual ported memory
13 * space. The allocator for that is here. When the communication
14 * process is reset, we reclaim the memory available. There is
15 * currently no deallocator for this memory.
16 * The amount of space available is platform dependent. On the
17 * MBX, the EPPC software loads additional microcode into the
18 * communication processor, and uses some of the DP ram for this
19 * purpose. Current, the first 512 bytes and the last 256 bytes of
20 * memory are used. Right now I am conservative and only use the
21 * memory that can never be used for microcode. If there are
22 * applications that require more DP ram, we can expand the boundaries
23 * but then we have to be careful of any downloaded microcode.
24 *
25 */
26
27 /*
28 * Michael Leslie <mleslie@lineo.com>
29 * adapted Dan Malek's ppc8xx drivers to M68360
30 *
31 */
32
33 #include <linux/errno.h>
34 #include <linux/sched.h>
35 #include <linux/kernel.h>
36 #include <linux/param.h>
37 #include <linux/string.h>
38 #include <linux/mm.h>
39 #include <linux/interrupt.h>
40 #include <asm/irq.h>
41 #include <asm/m68360.h>
42 #include <asm/commproc.h>
43
44 /* #include <asm/page.h> */
45 /* #include <asm/pgtable.h> */
46 extern void *_quicc_base;
47 extern unsigned int system_clock;
48
49
50 static uint dp_alloc_base; /* Starting offset in DP ram */
51 static uint dp_alloc_top; /* Max offset + 1 */
52
53 #if 0
54 static void *host_buffer; /* One page of host buffer */
55 static void *host_end; /* end + 1 */
56 #endif
57
58 /* struct cpm360_t *cpmp; */ /* Pointer to comm processor space */
59
60 QUICC *pquicc;
61 /* QUICC *quicc_dpram; */ /* mleslie - temporary; use extern pquicc elsewhere instead */
62
63
64 /* CPM interrupt vector functions. */
65 struct cpm_action {
66 void (*handler)(void *);
67 void *dev_id;
68 };
69 static struct cpm_action cpm_vecs[CPMVEC_NR];
70 static void cpm_interrupt(int irq, void * dev, struct pt_regs * regs);
71 static void cpm_error_interrupt(void *);
72
73 /* prototypes: */
74 void cpm_install_handler(int vec, void (*handler)(), void *dev_id);
75 void m360_cpm_reset(void);
76
77
78
79
m360_cpm_reset()80 void m360_cpm_reset()
81 {
82 /* pte_t *pte; */
83
84 pquicc = (struct quicc *)(_quicc_base); /* initialized in crt0_rXm.S */
85
86 /* Perform a CPM reset. */
87 pquicc->cp_cr = (SOFTWARE_RESET | CMD_FLAG);
88
89 /* Wait for CPM to become ready (should be 2 clocks). */
90 while (pquicc->cp_cr & CMD_FLAG);
91
92 /* On the recommendation of the 68360 manual, p. 7-60
93 * - Set sdma interrupt service mask to 7
94 * - Set sdma arbitration ID to 4
95 */
96 pquicc->sdma_sdcr = 0x0740;
97
98
99 /* Claim the DP memory for our use.
100 */
101 dp_alloc_base = CPM_DATAONLY_BASE;
102 dp_alloc_top = dp_alloc_base + CPM_DATAONLY_SIZE;
103
104
105 /* Set the host page for allocation.
106 */
107 /* host_buffer = host_page_addr; */
108 /* host_end = host_page_addr + PAGE_SIZE; */
109
110 /* pte = find_pte(&init_mm, host_page_addr); */
111 /* pte_val(*pte) |= _PAGE_NO_CACHE; */
112 /* flush_tlb_page(current->mm->mmap, host_buffer); */
113
114 /* Tell everyone where the comm processor resides.
115 */
116 /* cpmp = (cpm360_t *)commproc; */
117 }
118
119
120 /* This is called during init_IRQ. We used to do it above, but this
121 * was too early since init_IRQ was not yet called.
122 */
123 void
cpm_interrupt_init(void)124 cpm_interrupt_init(void)
125 {
126 /* Initialize the CPM interrupt controller.
127 * NOTE THAT pquicc had better have been initialized!
128 * reference: MC68360UM p. 7-377
129 */
130 pquicc->intr_cicr =
131 (CICR_SCD_SCC4 | CICR_SCC_SCC3 | CICR_SCB_SCC2 | CICR_SCA_SCC1) |
132 (CPM_INTERRUPT << 13) |
133 CICR_HP_MASK |
134 (CPM_VECTOR_BASE << 5) |
135 CICR_SPS;
136
137 /* mask all CPM interrupts from reaching the cpu32 core: */
138 pquicc->intr_cimr = 0;
139
140
141 /* mles - If I understand correctly, the 360 just pops over to the CPM
142 * specific vector, obviating the necessity to vector through the IRQ
143 * whose priority the CPM is set to. This needs a closer look, though.
144 */
145
146 /* Set our interrupt handler with the core CPU. */
147 /* if (request_irq(CPM_INTERRUPT, cpm_interrupt, 0, "cpm", NULL) != 0) */
148 /* panic("Could not allocate CPM IRQ!"); */
149
150 /* Install our own error handler.
151 */
152 /* I think we want to hold off on this one for the moment - mles */
153 /* cpm_install_handler(CPMVEC_ERROR, cpm_error_interrupt, NULL); */
154
155 /* master CPM interrupt enable */
156 /* pquicc->intr_cicr |= CICR_IEN; */ /* no such animal for 360 */
157 }
158
159
160
161 /* CPM interrupt controller interrupt.
162 */
163 static void
cpm_interrupt(int irq,void * dev,struct pt_regs * regs)164 cpm_interrupt(int irq, void * dev, struct pt_regs * regs)
165 {
166 /* uint vec; */
167
168 /* mles: Note that this stuff is currently being performed by
169 * M68360_do_irq(int vec, struct pt_regs *fp), in ../ints.c */
170
171 /* figure out the vector */
172 /* call that vector's handler */
173 /* clear the irq's bit in the service register */
174
175 #if 0 /* old 860 stuff: */
176 /* Get the vector by setting the ACK bit and then reading
177 * the register.
178 */
179 ((volatile immap_t *)IMAP_ADDR)->im_cpic.cpic_civr = 1;
180 vec = ((volatile immap_t *)IMAP_ADDR)->im_cpic.cpic_civr;
181 vec >>= 11;
182
183
184 if (cpm_vecs[vec].handler != 0)
185 (*cpm_vecs[vec].handler)(cpm_vecs[vec].dev_id);
186 else
187 ((immap_t *)IMAP_ADDR)->im_cpic.cpic_cimr &= ~(1 << vec);
188
189 /* After servicing the interrupt, we have to remove the status
190 * indicator.
191 */
192 ((immap_t *)IMAP_ADDR)->im_cpic.cpic_cisr |= (1 << vec);
193 #endif
194
195 }
196
197 /* The CPM can generate the error interrupt when there is a race condition
198 * between generating and masking interrupts. All we have to do is ACK it
199 * and return. This is a no-op function so we don't need any special
200 * tests in the interrupt handler.
201 */
202 static void
cpm_error_interrupt(void * dev)203 cpm_error_interrupt(void *dev)
204 {
205 }
206
207 /* Install a CPM interrupt handler.
208 */
209 void
cpm_install_handler(int vec,void (* handler)(),void * dev_id)210 cpm_install_handler(int vec, void (*handler)(), void *dev_id)
211 {
212
213 request_irq(vec, handler, 0, "timer", dev_id);
214
215 /* if (cpm_vecs[vec].handler != 0) */
216 /* printk(KERN_INFO "CPM interrupt %x replacing %x\n", */
217 /* (uint)handler, (uint)cpm_vecs[vec].handler); */
218 /* cpm_vecs[vec].handler = handler; */
219 /* cpm_vecs[vec].dev_id = dev_id; */
220
221 /* ((immap_t *)IMAP_ADDR)->im_cpic.cpic_cimr |= (1 << vec); */
222 /* pquicc->intr_cimr |= (1 << vec); */
223
224 }
225
226 /* Free a CPM interrupt handler.
227 */
228 void
cpm_free_handler(int vec)229 cpm_free_handler(int vec)
230 {
231 cpm_vecs[vec].handler = NULL;
232 cpm_vecs[vec].dev_id = NULL;
233 /* ((immap_t *)IMAP_ADDR)->im_cpic.cpic_cimr &= ~(1 << vec); */
234 pquicc->intr_cimr &= ~(1 << vec);
235 }
236
237
238
239
240 /* Allocate some memory from the dual ported ram. We may want to
241 * enforce alignment restrictions, but right now everyone is a good
242 * citizen.
243 */
244 uint
m360_cpm_dpalloc(uint size)245 m360_cpm_dpalloc(uint size)
246 {
247 uint retloc;
248
249 if ((dp_alloc_base + size) >= dp_alloc_top)
250 return(CPM_DP_NOSPACE);
251
252 retloc = dp_alloc_base;
253 dp_alloc_base += size;
254
255 return(retloc);
256 }
257
258
259 #if 0 /* mleslie - for now these are simply kmalloc'd */
260 /* We also own one page of host buffer space for the allocation of
261 * UART "fifos" and the like.
262 */
263 uint
264 m360_cpm_hostalloc(uint size)
265 {
266 uint retloc;
267
268 if ((host_buffer + size) >= host_end)
269 return(0);
270
271 retloc = host_buffer;
272 host_buffer += size;
273
274 return(retloc);
275 }
276 #endif
277
278
279 /* Set a baud rate generator. This needs lots of work. There are
280 * four BRGs, any of which can be wired to any channel.
281 * The internal baud rate clock is the system clock divided by 16.
282 * This assumes the baudrate is 16x oversampled by the uart.
283 */
284 /* #define BRG_INT_CLK (((bd_t *)__res)->bi_intfreq * 1000000) */
285 #define BRG_INT_CLK system_clock
286 #define BRG_UART_CLK (BRG_INT_CLK/16)
287
288 void
m360_cpm_setbrg(uint brg,uint rate)289 m360_cpm_setbrg(uint brg, uint rate)
290 {
291 volatile uint *bp;
292
293 /* This is good enough to get SMCs running.....
294 */
295 /* bp = (uint *)&cpmp->cp_brgc1; */
296 bp = (volatile uint *)(&pquicc->brgc[0].l);
297 bp += brg;
298 *bp = ((BRG_UART_CLK / rate - 1) << 1) | CPM_BRG_EN;
299 }
300
301
302 /*
303 * Local variables:
304 * c-indent-level: 4
305 * c-basic-offset: 4
306 * tab-width: 4
307 * End:
308 */
309