xref: /openbmc/qemu/hw/misc/imx_ccm.c (revision 534f6ff9)
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     .minimum_version_id_old = 1,
61     .fields = (VMStateField[]) {
62         VMSTATE_UINT32(ccmr, IMXCCMState),
63         VMSTATE_UINT32(pdr0, IMXCCMState),
64         VMSTATE_UINT32(pdr1, IMXCCMState),
65         VMSTATE_UINT32(mpctl, IMXCCMState),
66         VMSTATE_UINT32(spctl, IMXCCMState),
67         VMSTATE_UINT32_ARRAY(cgr, IMXCCMState, 3),
68         VMSTATE_UINT32(pmcr0, IMXCCMState),
69         VMSTATE_UINT32(pmcr1, IMXCCMState),
70         VMSTATE_UINT32(pll_refclk_freq, IMXCCMState),
71     },
72     .post_load = imx_ccm_post_load,
73 };
74 
75 /* CCMR */
76 #define CCMR_FPME (1<<0)
77 #define CCMR_MPE  (1<<3)
78 #define CCMR_MDS  (1<<7)
79 #define CCMR_FPMF (1<<26)
80 #define CCMR_PRCS (3<<1)
81 
82 /* PDR0 */
83 #define PDR0_MCU_PODF_SHIFT (0)
84 #define PDR0_MCU_PODF_MASK (0x7)
85 #define PDR0_MAX_PODF_SHIFT (3)
86 #define PDR0_MAX_PODF_MASK (0x7)
87 #define PDR0_IPG_PODF_SHIFT (6)
88 #define PDR0_IPG_PODF_MASK (0x3)
89 #define PDR0_NFC_PODF_SHIFT (8)
90 #define PDR0_NFC_PODF_MASK (0x7)
91 #define PDR0_HSP_PODF_SHIFT (11)
92 #define PDR0_HSP_PODF_MASK (0x7)
93 #define PDR0_PER_PODF_SHIFT (16)
94 #define PDR0_PER_PODF_MASK (0x1f)
95 #define PDR0_CSI_PODF_SHIFT (23)
96 #define PDR0_CSI_PODF_MASK (0x1ff)
97 
98 #define EXTRACT(value, name) (((value) >> PDR0_##name##_PODF_SHIFT) \
99                               & PDR0_##name##_PODF_MASK)
100 #define INSERT(value, name) (((value) & PDR0_##name##_PODF_MASK) << \
101                              PDR0_##name##_PODF_SHIFT)
102 /* PLL control registers */
103 #define PD(v) (((v) >> 26) & 0xf)
104 #define MFD(v) (((v) >> 16) & 0x3ff)
105 #define MFI(v) (((v) >> 10) & 0xf);
106 #define MFN(v) ((v) & 0x3ff)
107 
108 #define PLL_PD(x)               (((x) & 0xf) << 26)
109 #define PLL_MFD(x)              (((x) & 0x3ff) << 16)
110 #define PLL_MFI(x)              (((x) & 0xf) << 10)
111 #define PLL_MFN(x)              (((x) & 0x3ff) << 0)
112 
113 uint32_t imx_clock_frequency(DeviceState *dev, IMXClk clock)
114 {
115     IMXCCMState *s = IMX_CCM(dev);
116 
117     switch (clock) {
118     case NOCLK:
119         return 0;
120     case MCU:
121         return s->mcu_clk_freq;
122     case HSP:
123         return s->hsp_clk_freq;
124     case IPG:
125         return s->ipg_clk_freq;
126     case CLK_32k:
127         return CKIL_FREQ;
128     }
129     return 0;
130 }
131 
132 /*
133  * Calculate PLL output frequency
134  */
135 static uint32_t calc_pll(uint32_t pllreg, uint32_t base_freq)
136 {
137     int32_t mfn = MFN(pllreg);  /* Numerator */
138     uint32_t mfi = MFI(pllreg); /* Integer part */
139     uint32_t mfd = 1 + MFD(pllreg); /* Denominator */
140     uint32_t pd = 1 + PD(pllreg);   /* Pre-divider */
141 
142     if (mfi < 5) {
143         mfi = 5;
144     }
145     /* mfn is 10-bit signed twos-complement */
146     mfn <<= 32 - 10;
147     mfn >>= 32 - 10;
148 
149     return ((2 * (base_freq >> 10) * (mfi * mfd + mfn)) /
150             (mfd * pd)) << 10;
151 }
152 
153 static void update_clocks(IMXCCMState *s)
154 {
155     /*
156      * If we ever emulate more clocks, this should switch to a data-driven
157      * approach
158      */
159 
160     if ((s->ccmr & CCMR_PRCS) == 2) {
161         s->pll_refclk_freq = CKIL_FREQ * 1024;
162     } else {
163         s->pll_refclk_freq = CKIH_FREQ;
164     }
165 
166     /* ipg_clk_arm aka MCU clock */
167     if ((s->ccmr & CCMR_MDS) || !(s->ccmr & CCMR_MPE)) {
168         s->mcu_clk_freq = s->pll_refclk_freq;
169     } else {
170         s->mcu_clk_freq = calc_pll(s->mpctl, s->pll_refclk_freq);
171     }
172 
173     /* High-speed clock */
174     s->hsp_clk_freq = s->mcu_clk_freq / (1 + EXTRACT(s->pdr0, HSP));
175     s->ipg_clk_freq = s->hsp_clk_freq / (1 + EXTRACT(s->pdr0, IPG));
176 
177     DPRINTF("Clocks: mcu %uMHz, HSP %uMHz, IPG %uHz\n",
178             s->mcu_clk_freq / 1000000,
179             s->hsp_clk_freq / 1000000,
180             s->ipg_clk_freq);
181 }
182 
183 static void imx_ccm_reset(DeviceState *dev)
184 {
185     IMXCCMState *s = IMX_CCM(dev);
186 
187     s->ccmr = 0x074b0b7b;
188     s->pdr0 = 0xff870b48;
189     s->pdr1 = 0x49fcfe7f;
190     s->mpctl = PLL_PD(1) | PLL_MFD(0) | PLL_MFI(6) | PLL_MFN(0);
191     s->cgr[0] = s->cgr[1] = s->cgr[2] = 0xffffffff;
192     s->spctl = PLL_PD(1) | PLL_MFD(4) | PLL_MFI(0xc) | PLL_MFN(1);
193     s->pmcr0 = 0x80209828;
194 
195     update_clocks(s);
196 }
197 
198 static uint64_t imx_ccm_read(void *opaque, hwaddr offset,
199                                 unsigned size)
200 {
201     IMXCCMState *s = (IMXCCMState *)opaque;
202 
203     DPRINTF("read(offset=%x)", offset >> 2);
204     switch (offset >> 2) {
205     case 0: /* CCMR */
206         DPRINTF(" ccmr = 0x%x\n", s->ccmr);
207         return s->ccmr;
208     case 1:
209         DPRINTF(" pdr0 = 0x%x\n", s->pdr0);
210         return s->pdr0;
211     case 2:
212         DPRINTF(" pdr1 = 0x%x\n", s->pdr1);
213         return s->pdr1;
214     case 4:
215         DPRINTF(" mpctl = 0x%x\n", s->mpctl);
216         return s->mpctl;
217     case 6:
218         DPRINTF(" spctl = 0x%x\n", s->spctl);
219         return s->spctl;
220     case 8:
221         DPRINTF(" cgr0 = 0x%x\n", s->cgr[0]);
222         return s->cgr[0];
223     case 9:
224         DPRINTF(" cgr1 = 0x%x\n", s->cgr[1]);
225         return s->cgr[1];
226     case 10:
227         DPRINTF(" cgr2 = 0x%x\n", s->cgr[2]);
228         return s->cgr[2];
229     case 18: /* LTR1 */
230         return 0x00004040;
231     case 23:
232         DPRINTF(" pcmr0 = 0x%x\n", s->pmcr0);
233         return s->pmcr0;
234     }
235     DPRINTF(" return 0\n");
236     return 0;
237 }
238 
239 static void imx_ccm_write(void *opaque, hwaddr offset,
240                           uint64_t value, unsigned size)
241 {
242     IMXCCMState *s = (IMXCCMState *)opaque;
243 
244     DPRINTF("write(offset=%x, value = %x)\n",
245             offset >> 2, (unsigned int)value);
246     switch (offset >> 2) {
247     case 0:
248         s->ccmr = CCMR_FPMF | (value & 0x3b6fdfff);
249         break;
250     case 1:
251         s->pdr0 = value & 0xff9f3fff;
252         break;
253     case 2:
254         s->pdr1 = value;
255         break;
256     case 4:
257         s->mpctl = value & 0xbfff3fff;
258         break;
259     case 6:
260         s->spctl = value & 0xbfff3fff;
261         break;
262     case 8:
263         s->cgr[0] = value;
264         return;
265     case 9:
266         s->cgr[1] = value;
267         return;
268     case 10:
269         s->cgr[2] = value;
270         return;
271 
272     default:
273         return;
274     }
275     update_clocks(s);
276 }
277 
278 static const struct MemoryRegionOps imx_ccm_ops = {
279     .read = imx_ccm_read,
280     .write = imx_ccm_write,
281     .endianness = DEVICE_NATIVE_ENDIAN,
282 };
283 
284 static int imx_ccm_init(SysBusDevice *dev)
285 {
286     IMXCCMState *s = IMX_CCM(dev);
287 
288     memory_region_init_io(&s->iomem, OBJECT(dev), &imx_ccm_ops, s,
289                           "imx_ccm", 0x1000);
290     sysbus_init_mmio(dev, &s->iomem);
291 
292     return 0;
293 }
294 
295 static int imx_ccm_post_load(void *opaque, int version_id)
296 {
297     IMXCCMState *s = (IMXCCMState *)opaque;
298 
299     update_clocks(s);
300     return 0;
301 }
302 
303 static void imx_ccm_class_init(ObjectClass *klass, void *data)
304 {
305     DeviceClass *dc = DEVICE_CLASS(klass);
306     SysBusDeviceClass *sbc = SYS_BUS_DEVICE_CLASS(klass);
307 
308     sbc->init = imx_ccm_init;
309     dc->reset = imx_ccm_reset;
310     dc->vmsd = &vmstate_imx_ccm;
311     dc->desc = "i.MX Clock Control Module";
312 }
313 
314 static const TypeInfo imx_ccm_info = {
315     .name = TYPE_IMX_CCM,
316     .parent = TYPE_SYS_BUS_DEVICE,
317     .instance_size = sizeof(IMXCCMState),
318     .class_init = imx_ccm_class_init,
319 };
320 
321 static void imx_ccm_register_types(void)
322 {
323     type_register_static(&imx_ccm_info);
324 }
325 
326 type_init(imx_ccm_register_types)
327