xref: /openbmc/qemu/hw/misc/imx_ccm.c (revision 8f1e884b)
1 /*
2  * IMX31 Clock Control Module
3  *
4  * Copyright (C) 2012 NICTA
5  *
6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
7  * See the COPYING file in the top-level directory.
8  *
9  * To get the timer frequencies right, we need to emulate at least part of
10  * the CCM.
11  */
12 
13 #include "hw/hw.h"
14 #include "hw/sysbus.h"
15 #include "sysemu/sysemu.h"
16 #include "hw/arm/imx.h"
17 
18 #define CKIH_FREQ 26000000 /* 26MHz crystal input */
19 #define CKIL_FREQ    32768 /* nominal 32khz clock */
20 
21 
22 //#define DEBUG_CCM 1
23 #ifdef DEBUG_CCM
24 #define DPRINTF(fmt, args...) \
25 do { printf("imx_ccm: " fmt , ##args); } while (0)
26 #else
27 #define DPRINTF(fmt, args...) do {} while (0)
28 #endif
29 
30 static int imx_ccm_post_load(void *opaque, int version_id);
31 
32 #define TYPE_IMX_CCM "imx_ccm"
33 #define IMX_CCM(obj) OBJECT_CHECK(IMXCCMState, (obj), TYPE_IMX_CCM)
34 
35 typedef struct IMXCCMState {
36     SysBusDevice parent_obj;
37 
38     MemoryRegion iomem;
39 
40     uint32_t ccmr;
41     uint32_t pdr0;
42     uint32_t pdr1;
43     uint32_t mpctl;
44     uint32_t spctl;
45     uint32_t cgr[3];
46     uint32_t pmcr0;
47     uint32_t pmcr1;
48 
49     /* Frequencies precalculated on register changes */
50     uint32_t pll_refclk_freq;
51     uint32_t mcu_clk_freq;
52     uint32_t hsp_clk_freq;
53     uint32_t ipg_clk_freq;
54 } IMXCCMState;
55 
56 static const VMStateDescription vmstate_imx_ccm = {
57     .name = "imx-ccm",
58     .version_id = 1,
59     .minimum_version_id = 1,
60     .fields = (VMStateField[]) {
61         VMSTATE_UINT32(ccmr, IMXCCMState),
62         VMSTATE_UINT32(pdr0, IMXCCMState),
63         VMSTATE_UINT32(pdr1, IMXCCMState),
64         VMSTATE_UINT32(mpctl, IMXCCMState),
65         VMSTATE_UINT32(spctl, IMXCCMState),
66         VMSTATE_UINT32_ARRAY(cgr, IMXCCMState, 3),
67         VMSTATE_UINT32(pmcr0, IMXCCMState),
68         VMSTATE_UINT32(pmcr1, IMXCCMState),
69         VMSTATE_UINT32(pll_refclk_freq, IMXCCMState),
70     },
71     .post_load = imx_ccm_post_load,
72 };
73 
74 /* CCMR */
75 #define CCMR_FPME (1<<0)
76 #define CCMR_MPE  (1<<3)
77 #define CCMR_MDS  (1<<7)
78 #define CCMR_FPMF (1<<26)
79 #define CCMR_PRCS (3<<1)
80 
81 /* PDR0 */
82 #define PDR0_MCU_PODF_SHIFT (0)
83 #define PDR0_MCU_PODF_MASK (0x7)
84 #define PDR0_MAX_PODF_SHIFT (3)
85 #define PDR0_MAX_PODF_MASK (0x7)
86 #define PDR0_IPG_PODF_SHIFT (6)
87 #define PDR0_IPG_PODF_MASK (0x3)
88 #define PDR0_NFC_PODF_SHIFT (8)
89 #define PDR0_NFC_PODF_MASK (0x7)
90 #define PDR0_HSP_PODF_SHIFT (11)
91 #define PDR0_HSP_PODF_MASK (0x7)
92 #define PDR0_PER_PODF_SHIFT (16)
93 #define PDR0_PER_PODF_MASK (0x1f)
94 #define PDR0_CSI_PODF_SHIFT (23)
95 #define PDR0_CSI_PODF_MASK (0x1ff)
96 
97 #define EXTRACT(value, name) (((value) >> PDR0_##name##_PODF_SHIFT) \
98                               & PDR0_##name##_PODF_MASK)
99 #define INSERT(value, name) (((value) & PDR0_##name##_PODF_MASK) << \
100                              PDR0_##name##_PODF_SHIFT)
101 /* PLL control registers */
102 #define PD(v) (((v) >> 26) & 0xf)
103 #define MFD(v) (((v) >> 16) & 0x3ff)
104 #define MFI(v) (((v) >> 10) & 0xf);
105 #define MFN(v) ((v) & 0x3ff)
106 
107 #define PLL_PD(x)               (((x) & 0xf) << 26)
108 #define PLL_MFD(x)              (((x) & 0x3ff) << 16)
109 #define PLL_MFI(x)              (((x) & 0xf) << 10)
110 #define PLL_MFN(x)              (((x) & 0x3ff) << 0)
111 
112 uint32_t imx_clock_frequency(DeviceState *dev, IMXClk clock)
113 {
114     IMXCCMState *s = IMX_CCM(dev);
115 
116     switch (clock) {
117     case NOCLK:
118         return 0;
119     case MCU:
120         return s->mcu_clk_freq;
121     case HSP:
122         return s->hsp_clk_freq;
123     case IPG:
124         return s->ipg_clk_freq;
125     case CLK_32k:
126         return CKIL_FREQ;
127     }
128     return 0;
129 }
130 
131 /*
132  * Calculate PLL output frequency
133  */
134 static uint32_t calc_pll(uint32_t pllreg, uint32_t base_freq)
135 {
136     int32_t mfn = MFN(pllreg);  /* Numerator */
137     uint32_t mfi = MFI(pllreg); /* Integer part */
138     uint32_t mfd = 1 + MFD(pllreg); /* Denominator */
139     uint32_t pd = 1 + PD(pllreg);   /* Pre-divider */
140 
141     if (mfi < 5) {
142         mfi = 5;
143     }
144     /* mfn is 10-bit signed twos-complement */
145     mfn <<= 32 - 10;
146     mfn >>= 32 - 10;
147 
148     return ((2 * (base_freq >> 10) * (mfi * mfd + mfn)) /
149             (mfd * pd)) << 10;
150 }
151 
152 static void update_clocks(IMXCCMState *s)
153 {
154     /*
155      * If we ever emulate more clocks, this should switch to a data-driven
156      * approach
157      */
158 
159     if ((s->ccmr & CCMR_PRCS) == 2) {
160         s->pll_refclk_freq = CKIL_FREQ * 1024;
161     } else {
162         s->pll_refclk_freq = CKIH_FREQ;
163     }
164 
165     /* ipg_clk_arm aka MCU clock */
166     if ((s->ccmr & CCMR_MDS) || !(s->ccmr & CCMR_MPE)) {
167         s->mcu_clk_freq = s->pll_refclk_freq;
168     } else {
169         s->mcu_clk_freq = calc_pll(s->mpctl, s->pll_refclk_freq);
170     }
171 
172     /* High-speed clock */
173     s->hsp_clk_freq = s->mcu_clk_freq / (1 + EXTRACT(s->pdr0, HSP));
174     s->ipg_clk_freq = s->hsp_clk_freq / (1 + EXTRACT(s->pdr0, IPG));
175 
176     DPRINTF("Clocks: mcu %uMHz, HSP %uMHz, IPG %uHz\n",
177             s->mcu_clk_freq / 1000000,
178             s->hsp_clk_freq / 1000000,
179             s->ipg_clk_freq);
180 }
181 
182 static void imx_ccm_reset(DeviceState *dev)
183 {
184     IMXCCMState *s = IMX_CCM(dev);
185 
186     s->ccmr = 0x074b0b7b;
187     s->pdr0 = 0xff870b48;
188     s->pdr1 = 0x49fcfe7f;
189     s->mpctl = PLL_PD(1) | PLL_MFD(0) | PLL_MFI(6) | PLL_MFN(0);
190     s->cgr[0] = s->cgr[1] = s->cgr[2] = 0xffffffff;
191     s->spctl = PLL_PD(1) | PLL_MFD(4) | PLL_MFI(0xc) | PLL_MFN(1);
192     s->pmcr0 = 0x80209828;
193 
194     update_clocks(s);
195 }
196 
197 static uint64_t imx_ccm_read(void *opaque, hwaddr offset,
198                                 unsigned size)
199 {
200     IMXCCMState *s = (IMXCCMState *)opaque;
201 
202     DPRINTF("read(offset=%x)", offset >> 2);
203     switch (offset >> 2) {
204     case 0: /* CCMR */
205         DPRINTF(" ccmr = 0x%x\n", s->ccmr);
206         return s->ccmr;
207     case 1:
208         DPRINTF(" pdr0 = 0x%x\n", s->pdr0);
209         return s->pdr0;
210     case 2:
211         DPRINTF(" pdr1 = 0x%x\n", s->pdr1);
212         return s->pdr1;
213     case 4:
214         DPRINTF(" mpctl = 0x%x\n", s->mpctl);
215         return s->mpctl;
216     case 6:
217         DPRINTF(" spctl = 0x%x\n", s->spctl);
218         return s->spctl;
219     case 8:
220         DPRINTF(" cgr0 = 0x%x\n", s->cgr[0]);
221         return s->cgr[0];
222     case 9:
223         DPRINTF(" cgr1 = 0x%x\n", s->cgr[1]);
224         return s->cgr[1];
225     case 10:
226         DPRINTF(" cgr2 = 0x%x\n", s->cgr[2]);
227         return s->cgr[2];
228     case 18: /* LTR1 */
229         return 0x00004040;
230     case 23:
231         DPRINTF(" pcmr0 = 0x%x\n", s->pmcr0);
232         return s->pmcr0;
233     }
234     DPRINTF(" return 0\n");
235     return 0;
236 }
237 
238 static void imx_ccm_write(void *opaque, hwaddr offset,
239                           uint64_t value, unsigned size)
240 {
241     IMXCCMState *s = (IMXCCMState *)opaque;
242 
243     DPRINTF("write(offset=%x, value = %x)\n",
244             offset >> 2, (unsigned int)value);
245     switch (offset >> 2) {
246     case 0:
247         s->ccmr = CCMR_FPMF | (value & 0x3b6fdfff);
248         break;
249     case 1:
250         s->pdr0 = value & 0xff9f3fff;
251         break;
252     case 2:
253         s->pdr1 = value;
254         break;
255     case 4:
256         s->mpctl = value & 0xbfff3fff;
257         break;
258     case 6:
259         s->spctl = value & 0xbfff3fff;
260         break;
261     case 8:
262         s->cgr[0] = value;
263         return;
264     case 9:
265         s->cgr[1] = value;
266         return;
267     case 10:
268         s->cgr[2] = value;
269         return;
270 
271     default:
272         return;
273     }
274     update_clocks(s);
275 }
276 
277 static const struct MemoryRegionOps imx_ccm_ops = {
278     .read = imx_ccm_read,
279     .write = imx_ccm_write,
280     .endianness = DEVICE_NATIVE_ENDIAN,
281 };
282 
283 static int imx_ccm_init(SysBusDevice *dev)
284 {
285     IMXCCMState *s = IMX_CCM(dev);
286 
287     memory_region_init_io(&s->iomem, OBJECT(dev), &imx_ccm_ops, s,
288                           "imx_ccm", 0x1000);
289     sysbus_init_mmio(dev, &s->iomem);
290 
291     return 0;
292 }
293 
294 static int imx_ccm_post_load(void *opaque, int version_id)
295 {
296     IMXCCMState *s = (IMXCCMState *)opaque;
297 
298     update_clocks(s);
299     return 0;
300 }
301 
302 static void imx_ccm_class_init(ObjectClass *klass, void *data)
303 {
304     DeviceClass *dc = DEVICE_CLASS(klass);
305     SysBusDeviceClass *sbc = SYS_BUS_DEVICE_CLASS(klass);
306 
307     sbc->init = imx_ccm_init;
308     dc->reset = imx_ccm_reset;
309     dc->vmsd = &vmstate_imx_ccm;
310     dc->desc = "i.MX Clock Control Module";
311 }
312 
313 static const TypeInfo imx_ccm_info = {
314     .name = TYPE_IMX_CCM,
315     .parent = TYPE_SYS_BUS_DEVICE,
316     .instance_size = sizeof(IMXCCMState),
317     .class_init = imx_ccm_class_init,
318 };
319 
320 static void imx_ccm_register_types(void)
321 {
322     type_register_static(&imx_ccm_info);
323 }
324 
325 type_init(imx_ccm_register_types)
326