xref: /openbmc/qemu/hw/misc/imx25_ccm.c (revision 35658f6e)
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 "qemu/log.h"
17 
18 #ifndef DEBUG_IMX25_CCM
19 #define DEBUG_IMX25_CCM 0
20 #endif
21 
22 #define DPRINTF(fmt, args...) \
23     do { \
24         if (DEBUG_IMX25_CCM) { \
25             fprintf(stderr, "[%s]%s: " fmt , TYPE_IMX25_CCM, \
26                                              __func__, ##args); \
27         } \
28     } while (0)
29 
30 static char const *imx25_ccm_reg_name(uint32_t reg)
31 {
32     static char unknown[20];
33 
34     switch (reg) {
35     case IMX25_CCM_MPCTL_REG:
36         return "mpctl";
37     case IMX25_CCM_UPCTL_REG:
38         return "upctl";
39     case IMX25_CCM_CCTL_REG:
40         return "cctl";
41     case IMX25_CCM_CGCR0_REG:
42         return "cgcr0";
43     case IMX25_CCM_CGCR1_REG:
44         return "cgcr1";
45     case IMX25_CCM_CGCR2_REG:
46         return "cgcr2";
47     case IMX25_CCM_PCDR0_REG:
48         return "pcdr0";
49     case IMX25_CCM_PCDR1_REG:
50         return "pcdr1";
51     case IMX25_CCM_PCDR2_REG:
52         return "pcdr2";
53     case IMX25_CCM_PCDR3_REG:
54         return "pcdr3";
55     case IMX25_CCM_RCSR_REG:
56         return "rcsr";
57     case IMX25_CCM_CRDR_REG:
58         return "crdr";
59     case IMX25_CCM_DCVR0_REG:
60         return "dcvr0";
61     case IMX25_CCM_DCVR1_REG:
62         return "dcvr1";
63     case IMX25_CCM_DCVR2_REG:
64         return "dcvr2";
65     case IMX25_CCM_DCVR3_REG:
66         return "dcvr3";
67     case IMX25_CCM_LTR0_REG:
68         return "ltr0";
69     case IMX25_CCM_LTR1_REG:
70         return "ltr1";
71     case IMX25_CCM_LTR2_REG:
72         return "ltr2";
73     case IMX25_CCM_LTR3_REG:
74         return "ltr3";
75     case IMX25_CCM_LTBR0_REG:
76         return "ltbr0";
77     case IMX25_CCM_LTBR1_REG:
78         return "ltbr1";
79     case IMX25_CCM_PMCR0_REG:
80         return "pmcr0";
81     case IMX25_CCM_PMCR1_REG:
82         return "pmcr1";
83     case IMX25_CCM_PMCR2_REG:
84         return "pmcr2";
85     case IMX25_CCM_MCR_REG:
86         return "mcr";
87     case IMX25_CCM_LPIMR0_REG:
88         return "lpimr0";
89     case IMX25_CCM_LPIMR1_REG:
90         return "lpimr1";
91     default:
92         sprintf(unknown, "[%d ?]", reg);
93         return unknown;
94     }
95 }
96 #define CKIH_FREQ 24000000 /* 24MHz crystal input */
97 
98 static const VMStateDescription vmstate_imx25_ccm = {
99     .name = TYPE_IMX25_CCM,
100     .version_id = 1,
101     .minimum_version_id = 1,
102     .fields = (VMStateField[]) {
103         VMSTATE_UINT32_ARRAY(reg, IMX25CCMState, IMX25_CCM_MAX_REG),
104         VMSTATE_END_OF_LIST()
105     },
106 };
107 
108 static uint32_t imx25_ccm_get_mpll_clk(IMXCCMState *dev)
109 {
110     uint32_t freq;
111     IMX25CCMState *s = IMX25_CCM(dev);
112 
113     if (EXTRACT(s->reg[IMX25_CCM_CCTL_REG], MPLL_BYPASS)) {
114         freq = CKIH_FREQ;
115     } else {
116         freq = imx_ccm_calc_pll(s->reg[IMX25_CCM_MPCTL_REG], CKIH_FREQ);
117     }
118 
119     DPRINTF("freq = %d\n", freq);
120 
121     return freq;
122 }
123 
124 static uint32_t imx25_ccm_get_mcu_clk(IMXCCMState *dev)
125 {
126     uint32_t freq;
127     IMX25CCMState *s = IMX25_CCM(dev);
128 
129     freq = imx25_ccm_get_mpll_clk(dev);
130 
131     if (EXTRACT(s->reg[IMX25_CCM_CCTL_REG], ARM_SRC)) {
132         freq = (freq * 3 / 4);
133     }
134 
135     freq = freq / (1 + EXTRACT(s->reg[IMX25_CCM_CCTL_REG], ARM_CLK_DIV));
136 
137     DPRINTF("freq = %d\n", freq);
138 
139     return freq;
140 }
141 
142 static uint32_t imx25_ccm_get_ahb_clk(IMXCCMState *dev)
143 {
144     uint32_t freq;
145     IMX25CCMState *s = IMX25_CCM(dev);
146 
147     freq = imx25_ccm_get_mcu_clk(dev)
148            / (1 + EXTRACT(s->reg[IMX25_CCM_CCTL_REG], AHB_CLK_DIV));
149 
150     DPRINTF("freq = %d\n", freq);
151 
152     return freq;
153 }
154 
155 static uint32_t imx25_ccm_get_ipg_clk(IMXCCMState *dev)
156 {
157     uint32_t freq;
158 
159     freq = imx25_ccm_get_ahb_clk(dev) / 2;
160 
161     DPRINTF("freq = %d\n", freq);
162 
163     return freq;
164 }
165 
166 static uint32_t imx25_ccm_get_clock_frequency(IMXCCMState *dev, IMXClk clock)
167 {
168     uint32_t freq = 0;
169     DPRINTF("Clock = %d)\n", clock);
170 
171     switch (clock) {
172     case CLK_NONE:
173         break;
174     case CLK_IPG:
175     case CLK_IPG_HIGH:
176         freq = imx25_ccm_get_ipg_clk(dev);
177         break;
178     case CLK_32k:
179         freq = CKIL_FREQ;
180         break;
181     default:
182         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: unsupported clock %d\n",
183                       TYPE_IMX25_CCM, __func__, clock);
184         break;
185     }
186 
187     DPRINTF("Clock = %d) = %d\n", clock, freq);
188 
189     return freq;
190 }
191 
192 static void imx25_ccm_reset(DeviceState *dev)
193 {
194     IMX25CCMState *s = IMX25_CCM(dev);
195 
196     DPRINTF("\n");
197 
198     memset(s->reg, 0, IMX25_CCM_MAX_REG * sizeof(uint32_t));
199     s->reg[IMX25_CCM_MPCTL_REG] = 0x800b2c01;
200     s->reg[IMX25_CCM_UPCTL_REG] = 0x84042800;
201     /*
202      * The value below gives:
203      * CPU = 133 MHz, AHB = 66,5 MHz, IPG = 33 MHz.
204      */
205     s->reg[IMX25_CCM_CCTL_REG]  = 0xd0030000;
206     s->reg[IMX25_CCM_CGCR0_REG] = 0x028A0100;
207     s->reg[IMX25_CCM_CGCR1_REG] = 0x04008100;
208     s->reg[IMX25_CCM_CGCR2_REG] = 0x00000438;
209     s->reg[IMX25_CCM_PCDR0_REG] = 0x01010101;
210     s->reg[IMX25_CCM_PCDR1_REG] = 0x01010101;
211     s->reg[IMX25_CCM_PCDR2_REG] = 0x01010101;
212     s->reg[IMX25_CCM_PCDR3_REG] = 0x01010101;
213     s->reg[IMX25_CCM_PMCR0_REG] = 0x00A00000;
214     s->reg[IMX25_CCM_PMCR1_REG] = 0x0000A030;
215     s->reg[IMX25_CCM_PMCR2_REG] = 0x0000A030;
216     s->reg[IMX25_CCM_MCR_REG]   = 0x43000000;
217 
218     /*
219      * default boot will change the reset values to allow:
220      * CPU = 399 MHz, AHB = 133 MHz, IPG = 66,5 MHz.
221      * For some reason, this doesn't work. With the value below, linux
222      * detects a 88 MHz IPG CLK instead of 66,5 MHz.
223     s->reg[IMX25_CCM_CCTL_REG]  = 0x20032000;
224      */
225 }
226 
227 static uint64_t imx25_ccm_read(void *opaque, hwaddr offset, unsigned size)
228 {
229     uint32_t value = 0;
230     IMX25CCMState *s = (IMX25CCMState *)opaque;
231 
232     if (offset < 0x70) {
233         value = s->reg[offset >> 2];
234     } else {
235         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
236                       HWADDR_PRIx "\n", TYPE_IMX25_CCM, __func__, offset);
237     }
238 
239     DPRINTF("reg[%s] => 0x%" PRIx32 "\n", imx25_ccm_reg_name(offset >> 2),
240             value);
241 
242     return value;
243 }
244 
245 static void imx25_ccm_write(void *opaque, hwaddr offset, uint64_t value,
246                             unsigned size)
247 {
248     IMX25CCMState *s = (IMX25CCMState *)opaque;
249 
250     DPRINTF("reg[%s] <= 0x%" PRIx32 "\n", imx25_ccm_reg_name(offset >> 2),
251             (uint32_t)value);
252 
253     if (offset < 0x70) {
254         /*
255          * We will do a better implementation later. In particular some bits
256          * cannot be written to.
257          */
258         s->reg[offset >> 2] = value;
259     } else {
260         qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Bad register at offset 0x%"
261                       HWADDR_PRIx "\n", TYPE_IMX25_CCM, __func__, offset);
262     }
263 }
264 
265 static const struct MemoryRegionOps imx25_ccm_ops = {
266     .read = imx25_ccm_read,
267     .write = imx25_ccm_write,
268     .endianness = DEVICE_NATIVE_ENDIAN,
269     .valid = {
270         /*
271          * Our device would not work correctly if the guest was doing
272          * unaligned access. This might not be a limitation on the real
273          * device but in practice there is no reason for a guest to access
274          * this device unaligned.
275          */
276         .min_access_size = 4,
277         .max_access_size = 4,
278         .unaligned = false,
279     },
280 };
281 
282 static void imx25_ccm_init(Object *obj)
283 {
284     DeviceState *dev = DEVICE(obj);
285     SysBusDevice *sd = SYS_BUS_DEVICE(obj);
286     IMX25CCMState *s = IMX25_CCM(obj);
287 
288     memory_region_init_io(&s->iomem, OBJECT(dev), &imx25_ccm_ops, s,
289                           TYPE_IMX25_CCM, 0x1000);
290     sysbus_init_mmio(sd, &s->iomem);
291 }
292 
293 static void imx25_ccm_class_init(ObjectClass *klass, void *data)
294 {
295     DeviceClass *dc = DEVICE_CLASS(klass);
296     IMXCCMClass *ccm = IMX_CCM_CLASS(klass);
297 
298     dc->reset = imx25_ccm_reset;
299     dc->vmsd = &vmstate_imx25_ccm;
300     dc->desc = "i.MX25 Clock Control Module";
301 
302     ccm->get_clock_frequency = imx25_ccm_get_clock_frequency;
303 }
304 
305 static const TypeInfo imx25_ccm_info = {
306     .name          = TYPE_IMX25_CCM,
307     .parent        = TYPE_IMX_CCM,
308     .instance_size = sizeof(IMX25CCMState),
309     .instance_init = imx25_ccm_init,
310     .class_init    = imx25_ccm_class_init,
311 };
312 
313 static void imx25_ccm_register_types(void)
314 {
315     type_register_static(&imx25_ccm_info);
316 }
317 
318 type_init(imx25_ccm_register_types)
319