xref: /openbmc/qemu/hw/misc/imx25_ccm.c (revision 59a3a1c0)
1 /*
2  * IMX25 Clock Control Module
3  *
4  * Copyright (C) 2012 NICTA
5  * Updated by Jean-Christophe Dubois <jcd@tribudubois.net>
6  *
7  * This work is licensed under the terms of the GNU GPL, version 2 or later.
8  * See the COPYING file in the top-level directory.
9  *
10  * To get the timer frequencies right, we need to emulate at least part of
11  * the CCM.
12  */
13 
14 #include "qemu/osdep.h"
15 #include "hw/misc/imx25_ccm.h"
16 #include "migration/vmstate.h"
17 #include "qemu/log.h"
18 #include "qemu/module.h"
19 
20 #ifndef DEBUG_IMX25_CCM
21 #define DEBUG_IMX25_CCM 0
22 #endif
23 
24 #define DPRINTF(fmt, args...) \
25     do { \
26         if (DEBUG_IMX25_CCM) { \
27             fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX25_CCM, \
28                                              __func__, ##args); \
29         } \
30     } while (0)
31 
32 static const char *imx25_ccm_reg_name(uint32_t reg)
33 {
34     static char unknown[20];
35 
36     switch (reg) {
37     case IMX25_CCM_MPCTL_REG:
38         return "mpctl";
39     case IMX25_CCM_UPCTL_REG:
40         return "upctl";
41     case IMX25_CCM_CCTL_REG:
42         return "cctl";
43     case IMX25_CCM_CGCR0_REG:
44         return "cgcr0";
45     case IMX25_CCM_CGCR1_REG:
46         return "cgcr1";
47     case IMX25_CCM_CGCR2_REG:
48         return "cgcr2";
49     case IMX25_CCM_PCDR0_REG:
50         return "pcdr0";
51     case IMX25_CCM_PCDR1_REG:
52         return "pcdr1";
53     case IMX25_CCM_PCDR2_REG:
54         return "pcdr2";
55     case IMX25_CCM_PCDR3_REG:
56         return "pcdr3";
57     case IMX25_CCM_RCSR_REG:
58         return "rcsr";
59     case IMX25_CCM_CRDR_REG:
60         return "crdr";
61     case IMX25_CCM_DCVR0_REG:
62         return "dcvr0";
63     case IMX25_CCM_DCVR1_REG:
64         return "dcvr1";
65     case IMX25_CCM_DCVR2_REG:
66         return "dcvr2";
67     case IMX25_CCM_DCVR3_REG:
68         return "dcvr3";
69     case IMX25_CCM_LTR0_REG:
70         return "ltr0";
71     case IMX25_CCM_LTR1_REG:
72         return "ltr1";
73     case IMX25_CCM_LTR2_REG:
74         return "ltr2";
75     case IMX25_CCM_LTR3_REG:
76         return "ltr3";
77     case IMX25_CCM_LTBR0_REG:
78         return "ltbr0";
79     case IMX25_CCM_LTBR1_REG:
80         return "ltbr1";
81     case IMX25_CCM_PMCR0_REG:
82         return "pmcr0";
83     case IMX25_CCM_PMCR1_REG:
84         return "pmcr1";
85     case IMX25_CCM_PMCR2_REG:
86         return "pmcr2";
87     case IMX25_CCM_MCR_REG:
88         return "mcr";
89     case IMX25_CCM_LPIMR0_REG:
90         return "lpimr0";
91     case IMX25_CCM_LPIMR1_REG:
92         return "lpimr1";
93     default:
94         sprintf(unknown, "[%d ?]", reg);
95         return unknown;
96     }
97 }
98 #define CKIH_FREQ 24000000 /* 24MHz crystal input */
99 
100 static const VMStateDescription vmstate_imx25_ccm = {
101     .name = TYPE_IMX25_CCM,
102     .version_id = 1,
103     .minimum_version_id = 1,
104     .fields = (VMStateField[]) {
105         VMSTATE_UINT32_ARRAY(reg, IMX25CCMState, IMX25_CCM_MAX_REG),
106         VMSTATE_END_OF_LIST()
107     },
108 };
109 
110 static uint32_t imx25_ccm_get_mpll_clk(IMXCCMState *dev)
111 {
112     uint32_t freq;
113     IMX25CCMState *s = IMX25_CCM(dev);
114 
115     if (EXTRACT(s->reg[IMX25_CCM_CCTL_REG], MPLL_BYPASS)) {
116         freq = CKIH_FREQ;
117     } else {
118         freq = imx_ccm_calc_pll(s->reg[IMX25_CCM_MPCTL_REG], CKIH_FREQ);
119     }
120 
121     DPRINTF("freq = %d\n", freq);
122 
123     return freq;
124 }
125 
126 static uint32_t imx25_ccm_get_mcu_clk(IMXCCMState *dev)
127 {
128     uint32_t freq;
129     IMX25CCMState *s = IMX25_CCM(dev);
130 
131     freq = imx25_ccm_get_mpll_clk(dev);
132 
133     if (EXTRACT(s->reg[IMX25_CCM_CCTL_REG], ARM_SRC)) {
134         freq = (freq * 3 / 4);
135     }
136 
137     freq = freq / (1 + EXTRACT(s->reg[IMX25_CCM_CCTL_REG], ARM_CLK_DIV));
138 
139     DPRINTF("freq = %d\n", freq);
140 
141     return freq;
142 }
143 
144 static uint32_t imx25_ccm_get_ahb_clk(IMXCCMState *dev)
145 {
146     uint32_t freq;
147     IMX25CCMState *s = IMX25_CCM(dev);
148 
149     freq = imx25_ccm_get_mcu_clk(dev)
150            / (1 + EXTRACT(s->reg[IMX25_CCM_CCTL_REG], AHB_CLK_DIV));
151 
152     DPRINTF("freq = %d\n", freq);
153 
154     return freq;
155 }
156 
157 static uint32_t imx25_ccm_get_ipg_clk(IMXCCMState *dev)
158 {
159     uint32_t freq;
160 
161     freq = imx25_ccm_get_ahb_clk(dev) / 2;
162 
163     DPRINTF("freq = %d\n", freq);
164 
165     return freq;
166 }
167 
168 static uint32_t imx25_ccm_get_clock_frequency(IMXCCMState *dev, IMXClk clock)
169 {
170     uint32_t freq = 0;
171     DPRINTF("Clock = %d)\n", clock);
172 
173     switch (clock) {
174     case CLK_NONE:
175         break;
176     case CLK_IPG:
177     case CLK_IPG_HIGH:
178         freq = imx25_ccm_get_ipg_clk(dev);
179         break;
180     case CLK_32k:
181         freq = CKIL_FREQ;
182         break;
183     default:
184         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: unsupported clock %d\n",
185                       TYPE_IMX25_CCM, __func__, clock);
186         break;
187     }
188 
189     DPRINTF("Clock = %d) = %d\n", clock, freq);
190 
191     return freq;
192 }
193 
194 static void imx25_ccm_reset(DeviceState *dev)
195 {
196     IMX25CCMState *s = IMX25_CCM(dev);
197 
198     DPRINTF("\n");
199 
200     memset(s->reg, 0, IMX25_CCM_MAX_REG * sizeof(uint32_t));
201     s->reg[IMX25_CCM_MPCTL_REG] = 0x800b2c01;
202     s->reg[IMX25_CCM_UPCTL_REG] = 0x84042800;
203     /*
204      * The value below gives:
205      * CPU = 133 MHz, AHB = 66,5 MHz, IPG = 33 MHz.
206      */
207     s->reg[IMX25_CCM_CCTL_REG]  = 0xd0030000;
208     s->reg[IMX25_CCM_CGCR0_REG] = 0x028A0100;
209     s->reg[IMX25_CCM_CGCR1_REG] = 0x04008100;
210     s->reg[IMX25_CCM_CGCR2_REG] = 0x00000438;
211     s->reg[IMX25_CCM_PCDR0_REG] = 0x01010101;
212     s->reg[IMX25_CCM_PCDR1_REG] = 0x01010101;
213     s->reg[IMX25_CCM_PCDR2_REG] = 0x01010101;
214     s->reg[IMX25_CCM_PCDR3_REG] = 0x01010101;
215     s->reg[IMX25_CCM_PMCR0_REG] = 0x00A00000;
216     s->reg[IMX25_CCM_PMCR1_REG] = 0x0000A030;
217     s->reg[IMX25_CCM_PMCR2_REG] = 0x0000A030;
218     s->reg[IMX25_CCM_MCR_REG]   = 0x43000000;
219 
220     /*
221      * default boot will change the reset values to allow:
222      * CPU = 399 MHz, AHB = 133 MHz, IPG = 66,5 MHz.
223      * For some reason, this doesn't work. With the value below, linux
224      * detects a 88 MHz IPG CLK instead of 66,5 MHz.
225     s->reg[IMX25_CCM_CCTL_REG]  = 0x20032000;
226      */
227 }
228 
229 static uint64_t imx25_ccm_read(void *opaque, hwaddr offset, unsigned size)
230 {
231     uint32_t value = 0;
232     IMX25CCMState *s = (IMX25CCMState *)opaque;
233 
234     if (offset < 0x70) {
235         value = s->reg[offset >> 2];
236     } else {
237         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
238                       HWADDR_PRIx "\n", TYPE_IMX25_CCM, __func__, offset);
239     }
240 
241     DPRINTF("reg[%s] => 0x%" PRIx32 "\n", imx25_ccm_reg_name(offset >> 2),
242             value);
243 
244     return value;
245 }
246 
247 static void imx25_ccm_write(void *opaque, hwaddr offset, uint64_t value,
248                             unsigned size)
249 {
250     IMX25CCMState *s = (IMX25CCMState *)opaque;
251 
252     DPRINTF("reg[%s] <= 0x%" PRIx32 "\n", imx25_ccm_reg_name(offset >> 2),
253             (uint32_t)value);
254 
255     if (offset < 0x70) {
256         /*
257          * We will do a better implementation later. In particular some bits
258          * cannot be written to.
259          */
260         s->reg[offset >> 2] = value;
261     } else {
262         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
263                       HWADDR_PRIx "\n", TYPE_IMX25_CCM, __func__, offset);
264     }
265 }
266 
267 static const struct MemoryRegionOps imx25_ccm_ops = {
268     .read = imx25_ccm_read,
269     .write = imx25_ccm_write,
270     .endianness = DEVICE_NATIVE_ENDIAN,
271     .valid = {
272         /*
273          * Our device would not work correctly if the guest was doing
274          * unaligned access. This might not be a limitation on the real
275          * device but in practice there is no reason for a guest to access
276          * this device unaligned.
277          */
278         .min_access_size = 4,
279         .max_access_size = 4,
280         .unaligned = false,
281     },
282 };
283 
284 static void imx25_ccm_init(Object *obj)
285 {
286     DeviceState *dev = DEVICE(obj);
287     SysBusDevice *sd = SYS_BUS_DEVICE(obj);
288     IMX25CCMState *s = IMX25_CCM(obj);
289 
290     memory_region_init_io(&s->iomem, OBJECT(dev), &imx25_ccm_ops, s,
291                           TYPE_IMX25_CCM, 0x1000);
292     sysbus_init_mmio(sd, &s->iomem);
293 }
294 
295 static void imx25_ccm_class_init(ObjectClass *klass, void *data)
296 {
297     DeviceClass *dc = DEVICE_CLASS(klass);
298     IMXCCMClass *ccm = IMX_CCM_CLASS(klass);
299 
300     dc->reset = imx25_ccm_reset;
301     dc->vmsd = &vmstate_imx25_ccm;
302     dc->desc = "i.MX25 Clock Control Module";
303 
304     ccm->get_clock_frequency = imx25_ccm_get_clock_frequency;
305 }
306 
307 static const TypeInfo imx25_ccm_info = {
308     .name          = TYPE_IMX25_CCM,
309     .parent        = TYPE_IMX_CCM,
310     .instance_size = sizeof(IMX25CCMState),
311     .instance_init = imx25_ccm_init,
312     .class_init    = imx25_ccm_class_init,
313 };
314 
315 static void imx25_ccm_register_types(void)
316 {
317     type_register_static(&imx25_ccm_info);
318 }
319 
320 type_init(imx25_ccm_register_types)
321