xref: /openbmc/qemu/hw/misc/imx_ccm.c (revision 2993683b)
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 typedef struct {
33     SysBusDevice busdev;
34     MemoryRegion iomem;
35 
36     uint32_t ccmr;
37     uint32_t pdr0;
38     uint32_t pdr1;
39     uint32_t mpctl;
40     uint32_t spctl;
41     uint32_t cgr[3];
42     uint32_t pmcr0;
43     uint32_t pmcr1;
44 
45     /* Frequencies precalculated on register changes */
46     uint32_t pll_refclk_freq;
47     uint32_t mcu_clk_freq;
48     uint32_t hsp_clk_freq;
49     uint32_t ipg_clk_freq;
50 } IMXCCMState;
51 
52 static const VMStateDescription vmstate_imx_ccm = {
53     .name = "imx-ccm",
54     .version_id = 1,
55     .minimum_version_id = 1,
56     .minimum_version_id_old = 1,
57     .fields = (VMStateField[]) {
58         VMSTATE_UINT32(ccmr, IMXCCMState),
59         VMSTATE_UINT32(pdr0, IMXCCMState),
60         VMSTATE_UINT32(pdr1, IMXCCMState),
61         VMSTATE_UINT32(mpctl, IMXCCMState),
62         VMSTATE_UINT32(spctl, IMXCCMState),
63         VMSTATE_UINT32_ARRAY(cgr, IMXCCMState, 3),
64         VMSTATE_UINT32(pmcr0, IMXCCMState),
65         VMSTATE_UINT32(pmcr1, IMXCCMState),
66         VMSTATE_UINT32(pll_refclk_freq, IMXCCMState),
67     },
68     .post_load = imx_ccm_post_load,
69 };
70 
71 /* CCMR */
72 #define CCMR_FPME (1<<0)
73 #define CCMR_MPE  (1<<3)
74 #define CCMR_MDS  (1<<7)
75 #define CCMR_FPMF (1<<26)
76 #define CCMR_PRCS (3<<1)
77 
78 /* PDR0 */
79 #define PDR0_MCU_PODF_SHIFT (0)
80 #define PDR0_MCU_PODF_MASK (0x7)
81 #define PDR0_MAX_PODF_SHIFT (3)
82 #define PDR0_MAX_PODF_MASK (0x7)
83 #define PDR0_IPG_PODF_SHIFT (6)
84 #define PDR0_IPG_PODF_MASK (0x3)
85 #define PDR0_NFC_PODF_SHIFT (8)
86 #define PDR0_NFC_PODF_MASK (0x7)
87 #define PDR0_HSP_PODF_SHIFT (11)
88 #define PDR0_HSP_PODF_MASK (0x7)
89 #define PDR0_PER_PODF_SHIFT (16)
90 #define PDR0_PER_PODF_MASK (0x1f)
91 #define PDR0_CSI_PODF_SHIFT (23)
92 #define PDR0_CSI_PODF_MASK (0x1ff)
93 
94 #define EXTRACT(value, name) (((value) >> PDR0_##name##_PODF_SHIFT) \
95                               & PDR0_##name##_PODF_MASK)
96 #define INSERT(value, name) (((value) & PDR0_##name##_PODF_MASK) << \
97                              PDR0_##name##_PODF_SHIFT)
98 /* PLL control registers */
99 #define PD(v) (((v) >> 26) & 0xf)
100 #define MFD(v) (((v) >> 16) & 0x3ff)
101 #define MFI(v) (((v) >> 10) & 0xf);
102 #define MFN(v) ((v) & 0x3ff)
103 
104 #define PLL_PD(x)               (((x) & 0xf) << 26)
105 #define PLL_MFD(x)              (((x) & 0x3ff) << 16)
106 #define PLL_MFI(x)              (((x) & 0xf) << 10)
107 #define PLL_MFN(x)              (((x) & 0x3ff) << 0)
108 
109 uint32_t imx_clock_frequency(DeviceState *dev, IMXClk clock)
110 {
111     IMXCCMState *s = container_of(dev, IMXCCMState, busdev.qdev);
112 
113     switch (clock) {
114     case NOCLK:
115         return 0;
116     case MCU:
117         return s->mcu_clk_freq;
118     case HSP:
119         return s->hsp_clk_freq;
120     case IPG:
121         return s->ipg_clk_freq;
122     case CLK_32k:
123         return CKIL_FREQ;
124     }
125     return 0;
126 }
127 
128 /*
129  * Calculate PLL output frequency
130  */
131 static uint32_t calc_pll(uint32_t pllreg, uint32_t base_freq)
132 {
133     int32_t mfn = MFN(pllreg);  /* Numerator */
134     uint32_t mfi = MFI(pllreg); /* Integer part */
135     uint32_t mfd = 1 + MFD(pllreg); /* Denominator */
136     uint32_t pd = 1 + PD(pllreg);   /* Pre-divider */
137 
138     if (mfi < 5) {
139         mfi = 5;
140     }
141     /* mfn is 10-bit signed twos-complement */
142     mfn <<= 32 - 10;
143     mfn >>= 32 - 10;
144 
145     return ((2 * (base_freq >> 10) * (mfi * mfd + mfn)) /
146             (mfd * pd)) << 10;
147 }
148 
149 static void update_clocks(IMXCCMState *s)
150 {
151     /*
152      * If we ever emulate more clocks, this should switch to a data-driven
153      * approach
154      */
155 
156     if ((s->ccmr & CCMR_PRCS) == 1) {
157         s->pll_refclk_freq = CKIL_FREQ * 1024;
158     } else {
159         s->pll_refclk_freq = CKIH_FREQ;
160     }
161 
162     /* ipg_clk_arm aka MCU clock */
163     if ((s->ccmr & CCMR_MDS) || !(s->ccmr & CCMR_MPE)) {
164         s->mcu_clk_freq = s->pll_refclk_freq;
165     } else {
166         s->mcu_clk_freq = calc_pll(s->mpctl, s->pll_refclk_freq);
167     }
168 
169     /* High-speed clock */
170     s->hsp_clk_freq = s->mcu_clk_freq / (1 + EXTRACT(s->pdr0, HSP));
171     s->ipg_clk_freq = s->hsp_clk_freq / (1 + EXTRACT(s->pdr0, IPG));
172 
173     DPRINTF("Clocks: mcu %uMHz, HSP %uMHz, IPG %uHz\n",
174             s->mcu_clk_freq / 1000000,
175             s->hsp_clk_freq / 1000000,
176             s->ipg_clk_freq);
177 }
178 
179 static void imx_ccm_reset(DeviceState *dev)
180 {
181     IMXCCMState *s = container_of(dev, IMXCCMState, busdev.qdev);
182 
183     s->ccmr = 0x074b0b7b;
184     s->pdr0 = 0xff870b48;
185     s->pdr1 = 0x49fcfe7f;
186     s->mpctl = PLL_PD(1) | PLL_MFD(0) | PLL_MFI(6) | PLL_MFN(0);
187     s->cgr[0] = s->cgr[1] = s->cgr[2] = 0xffffffff;
188     s->spctl = PLL_PD(1) | PLL_MFD(4) | PLL_MFI(0xc) | PLL_MFN(1);
189     s->pmcr0 = 0x80209828;
190 
191     update_clocks(s);
192 }
193 
194 static uint64_t imx_ccm_read(void *opaque, hwaddr offset,
195                                 unsigned size)
196 {
197     IMXCCMState *s = (IMXCCMState *)opaque;
198 
199     DPRINTF("read(offset=%x)", offset >> 2);
200     switch (offset >> 2) {
201     case 0: /* CCMR */
202         DPRINTF(" ccmr = 0x%x\n", s->ccmr);
203         return s->ccmr;
204     case 1:
205         DPRINTF(" pdr0 = 0x%x\n", s->pdr0);
206         return s->pdr0;
207     case 2:
208         DPRINTF(" pdr1 = 0x%x\n", s->pdr1);
209         return s->pdr1;
210     case 4:
211         DPRINTF(" mpctl = 0x%x\n", s->mpctl);
212         return s->mpctl;
213     case 6:
214         DPRINTF(" spctl = 0x%x\n", s->spctl);
215         return s->spctl;
216     case 8:
217         DPRINTF(" cgr0 = 0x%x\n", s->cgr[0]);
218         return s->cgr[0];
219     case 9:
220         DPRINTF(" cgr1 = 0x%x\n", s->cgr[1]);
221         return s->cgr[1];
222     case 10:
223         DPRINTF(" cgr2 = 0x%x\n", s->cgr[2]);
224         return s->cgr[2];
225     case 18: /* LTR1 */
226         return 0x00004040;
227     case 23:
228         DPRINTF(" pcmr0 = 0x%x\n", s->pmcr0);
229         return s->pmcr0;
230     }
231     DPRINTF(" return 0\n");
232     return 0;
233 }
234 
235 static void imx_ccm_write(void *opaque, hwaddr offset,
236                           uint64_t value, unsigned size)
237 {
238     IMXCCMState *s = (IMXCCMState *)opaque;
239 
240     DPRINTF("write(offset=%x, value = %x)\n",
241             offset >> 2, (unsigned int)value);
242     switch (offset >> 2) {
243     case 0:
244         s->ccmr = CCMR_FPMF | (value & 0x3b6fdfff);
245         break;
246     case 1:
247         s->pdr0 = value & 0xff9f3fff;
248         break;
249     case 2:
250         s->pdr1 = value;
251         break;
252     case 4:
253         s->mpctl = value & 0xbfff3fff;
254         break;
255     case 6:
256         s->spctl = value & 0xbfff3fff;
257         break;
258     case 8:
259         s->cgr[0] = value;
260         return;
261     case 9:
262         s->cgr[1] = value;
263         return;
264     case 10:
265         s->cgr[2] = value;
266         return;
267 
268     default:
269         return;
270     }
271     update_clocks(s);
272 }
273 
274 static const struct MemoryRegionOps imx_ccm_ops = {
275     .read = imx_ccm_read,
276     .write = imx_ccm_write,
277     .endianness = DEVICE_NATIVE_ENDIAN,
278 };
279 
280 static int imx_ccm_init(SysBusDevice *dev)
281 {
282     IMXCCMState *s = FROM_SYSBUS(typeof(*s), dev);
283 
284     memory_region_init_io(&s->iomem, &imx_ccm_ops, s, "imx_ccm", 0x1000);
285     sysbus_init_mmio(dev, &s->iomem);
286 
287     return 0;
288 }
289 
290 static int imx_ccm_post_load(void *opaque, int version_id)
291 {
292     IMXCCMState *s = (IMXCCMState *)opaque;
293 
294     update_clocks(s);
295     return 0;
296 }
297 
298 static void imx_ccm_class_init(ObjectClass *klass, void *data)
299 {
300     DeviceClass *dc = DEVICE_CLASS(klass);
301     SysBusDeviceClass *sbc = SYS_BUS_DEVICE_CLASS(klass);
302 
303     sbc->init = imx_ccm_init;
304     dc->reset = imx_ccm_reset;
305     dc->vmsd = &vmstate_imx_ccm;
306     dc->desc = "i.MX Clock Control Module";
307 }
308 
309 static const TypeInfo imx_ccm_info = {
310     .name = "imx_ccm",
311     .parent = TYPE_SYS_BUS_DEVICE,
312     .instance_size = sizeof(IMXCCMState),
313     .class_init = imx_ccm_class_init,
314 };
315 
316 static void imx_ccm_register_types(void)
317 {
318     type_register_static(&imx_ccm_info);
319 }
320 
321 type_init(imx_ccm_register_types)
322