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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * PolarFire SoC MSS/core complex clock control
4 *
5 * Copyright (C) 2020-2022 Microchip Technology Inc. All rights reserved.
6 */
7#include <linux/auxiliary_bus.h>
8#include <linux/clk-provider.h>
9#include <linux/io.h>
10#include <linux/module.h>
11#include <linux/platform_device.h>
12#include <linux/slab.h>
13#include <dt-bindings/clock/microchip,mpfs-clock.h>
14#include <soc/microchip/mpfs.h>
15
16/* address offset of control registers */
17#define REG_MSSPLL_REF_CR 0x08u
18#define REG_MSSPLL_POSTDIV_CR 0x10u
19#define REG_MSSPLL_SSCG_2_CR 0x2Cu
20#define REG_CLOCK_CONFIG_CR 0x08u
21#define REG_RTC_CLOCK_CR 0x0Cu
22#define REG_SUBBLK_CLOCK_CR 0x84u
23#define REG_SUBBLK_RESET_CR 0x88u
24
25#define MSSPLL_FBDIV_SHIFT 0x00u
26#define MSSPLL_FBDIV_WIDTH 0x0Cu
27#define MSSPLL_REFDIV_SHIFT 0x08u
28#define MSSPLL_REFDIV_WIDTH 0x06u
29#define MSSPLL_POSTDIV_SHIFT 0x08u
30#define MSSPLL_POSTDIV_WIDTH 0x07u
31#define MSSPLL_FIXED_DIV 4u
32
33struct mpfs_clock_data {
34 struct device *dev;
35 void __iomem *base;
36 void __iomem *msspll_base;
37 struct clk_hw_onecell_data hw_data;
38};
39
40struct mpfs_msspll_hw_clock {
41 void __iomem *base;
42 unsigned int id;
43 u32 reg_offset;
44 u32 shift;
45 u32 width;
46 u32 flags;
47 struct clk_hw hw;
48 struct clk_init_data init;
49};
50
51#define to_mpfs_msspll_clk(_hw) container_of(_hw, struct mpfs_msspll_hw_clock, hw)
52
53struct mpfs_cfg_hw_clock {
54 struct clk_divider cfg;
55 struct clk_init_data init;
56 unsigned int id;
57 u32 reg_offset;
58};
59
60struct mpfs_periph_hw_clock {
61 struct clk_gate periph;
62 unsigned int id;
63};
64
65/*
66 * mpfs_clk_lock prevents anything else from writing to the
67 * mpfs clk block while a software locked register is being written.
68 */
69static DEFINE_SPINLOCK(mpfs_clk_lock);
70
71static const struct clk_parent_data mpfs_ext_ref[] = {
72 { .index = 0 },
73};
74
75static const struct clk_div_table mpfs_div_cpu_axi_table[] = {
76 { 0, 1 }, { 1, 2 }, { 2, 4 }, { 3, 8 },
77 { 0, 0 }
78};
79
80static const struct clk_div_table mpfs_div_ahb_table[] = {
81 { 1, 2 }, { 2, 4}, { 3, 8 },
82 { 0, 0 }
83};
84
85/*
86 * The only two supported reference clock frequencies for the PolarFire SoC are
87 * 100 and 125 MHz, as the rtc reference is required to be 1 MHz.
88 * It therefore only needs to have divider table entries corresponding to
89 * divide by 100 and 125.
90 */
91static const struct clk_div_table mpfs_div_rtcref_table[] = {
92 { 100, 100 }, { 125, 125 },
93 { 0, 0 }
94};
95
96static unsigned long mpfs_clk_msspll_recalc_rate(struct clk_hw *hw, unsigned long prate)
97{
98 struct mpfs_msspll_hw_clock *msspll_hw = to_mpfs_msspll_clk(hw);
99 void __iomem *mult_addr = msspll_hw->base + msspll_hw->reg_offset;
100 void __iomem *ref_div_addr = msspll_hw->base + REG_MSSPLL_REF_CR;
101 void __iomem *postdiv_addr = msspll_hw->base + REG_MSSPLL_POSTDIV_CR;
102 u32 mult, ref_div, postdiv;
103
104 mult = readl_relaxed(mult_addr) >> MSSPLL_FBDIV_SHIFT;
105 mult &= clk_div_mask(MSSPLL_FBDIV_WIDTH);
106 ref_div = readl_relaxed(ref_div_addr) >> MSSPLL_REFDIV_SHIFT;
107 ref_div &= clk_div_mask(MSSPLL_REFDIV_WIDTH);
108 postdiv = readl_relaxed(postdiv_addr) >> MSSPLL_POSTDIV_SHIFT;
109 postdiv &= clk_div_mask(MSSPLL_POSTDIV_WIDTH);
110
111 return prate * mult / (ref_div * MSSPLL_FIXED_DIV * postdiv);
112}
113
114static long mpfs_clk_msspll_round_rate(struct clk_hw *hw, unsigned long rate, unsigned long *prate)
115{
116 struct mpfs_msspll_hw_clock *msspll_hw = to_mpfs_msspll_clk(hw);
117 void __iomem *mult_addr = msspll_hw->base + msspll_hw->reg_offset;
118 void __iomem *ref_div_addr = msspll_hw->base + REG_MSSPLL_REF_CR;
119 u32 mult, ref_div;
120 unsigned long rate_before_ctrl;
121
122 mult = readl_relaxed(mult_addr) >> MSSPLL_FBDIV_SHIFT;
123 mult &= clk_div_mask(MSSPLL_FBDIV_WIDTH);
124 ref_div = readl_relaxed(ref_div_addr) >> MSSPLL_REFDIV_SHIFT;
125 ref_div &= clk_div_mask(MSSPLL_REFDIV_WIDTH);
126
127 rate_before_ctrl = rate * (ref_div * MSSPLL_FIXED_DIV) / mult;
128
129 return divider_round_rate(hw, rate_before_ctrl, prate, NULL, MSSPLL_POSTDIV_WIDTH,
130 msspll_hw->flags);
131}
132
133static int mpfs_clk_msspll_set_rate(struct clk_hw *hw, unsigned long rate, unsigned long prate)
134{
135 struct mpfs_msspll_hw_clock *msspll_hw = to_mpfs_msspll_clk(hw);
136 void __iomem *mult_addr = msspll_hw->base + msspll_hw->reg_offset;
137 void __iomem *ref_div_addr = msspll_hw->base + REG_MSSPLL_REF_CR;
138 void __iomem *postdiv_addr = msspll_hw->base + REG_MSSPLL_POSTDIV_CR;
139 u32 mult, ref_div, postdiv;
140 int divider_setting;
141 unsigned long rate_before_ctrl, flags;
142
143 mult = readl_relaxed(mult_addr) >> MSSPLL_FBDIV_SHIFT;
144 mult &= clk_div_mask(MSSPLL_FBDIV_WIDTH);
145 ref_div = readl_relaxed(ref_div_addr) >> MSSPLL_REFDIV_SHIFT;
146 ref_div &= clk_div_mask(MSSPLL_REFDIV_WIDTH);
147
148 rate_before_ctrl = rate * (ref_div * MSSPLL_FIXED_DIV) / mult;
149 divider_setting = divider_get_val(rate_before_ctrl, prate, NULL, MSSPLL_POSTDIV_WIDTH,
150 msspll_hw->flags);
151
152 if (divider_setting < 0)
153 return divider_setting;
154
155 spin_lock_irqsave(&mpfs_clk_lock, flags);
156
157 postdiv = readl_relaxed(postdiv_addr);
158 postdiv &= ~(clk_div_mask(MSSPLL_POSTDIV_WIDTH) << MSSPLL_POSTDIV_SHIFT);
159 writel_relaxed(postdiv, postdiv_addr);
160
161 spin_unlock_irqrestore(&mpfs_clk_lock, flags);
162
163 return 0;
164}
165
166static const struct clk_ops mpfs_clk_msspll_ops = {
167 .recalc_rate = mpfs_clk_msspll_recalc_rate,
168 .round_rate = mpfs_clk_msspll_round_rate,
169 .set_rate = mpfs_clk_msspll_set_rate,
170};
171
172#define CLK_PLL(_id, _name, _parent, _shift, _width, _flags, _offset) { \
173 .id = _id, \
174 .shift = _shift, \
175 .width = _width, \
176 .reg_offset = _offset, \
177 .flags = _flags, \
178 .hw.init = CLK_HW_INIT_PARENTS_DATA(_name, _parent, &mpfs_clk_msspll_ops, 0), \
179}
180
181static struct mpfs_msspll_hw_clock mpfs_msspll_clks[] = {
182 CLK_PLL(CLK_MSSPLL, "clk_msspll", mpfs_ext_ref, MSSPLL_FBDIV_SHIFT,
183 MSSPLL_FBDIV_WIDTH, 0, REG_MSSPLL_SSCG_2_CR),
184};
185
186static int mpfs_clk_register_mssplls(struct device *dev, struct mpfs_msspll_hw_clock *msspll_hws,
187 unsigned int num_clks, struct mpfs_clock_data *data)
188{
189 unsigned int i;
190 int ret;
191
192 for (i = 0; i < num_clks; i++) {
193 struct mpfs_msspll_hw_clock *msspll_hw = &msspll_hws[i];
194
195 msspll_hw->base = data->msspll_base;
196 ret = devm_clk_hw_register(dev, &msspll_hw->hw);
197 if (ret)
198 return dev_err_probe(dev, ret, "failed to register msspll id: %d\n",
199 CLK_MSSPLL);
200
201 data->hw_data.hws[msspll_hw->id] = &msspll_hw->hw;
202 }
203
204 return 0;
205}
206
207/*
208 * "CFG" clocks
209 */
210
211#define CLK_CFG(_id, _name, _parent, _shift, _width, _table, _flags, _offset) { \
212 .id = _id, \
213 .cfg.shift = _shift, \
214 .cfg.width = _width, \
215 .cfg.table = _table, \
216 .reg_offset = _offset, \
217 .cfg.flags = _flags, \
218 .cfg.hw.init = CLK_HW_INIT(_name, _parent, &clk_divider_ops, 0), \
219 .cfg.lock = &mpfs_clk_lock, \
220}
221
222#define CLK_CPU_OFFSET 0u
223#define CLK_AXI_OFFSET 1u
224#define CLK_AHB_OFFSET 2u
225#define CLK_RTCREF_OFFSET 3u
226
227static struct mpfs_cfg_hw_clock mpfs_cfg_clks[] = {
228 CLK_CFG(CLK_CPU, "clk_cpu", "clk_msspll", 0, 2, mpfs_div_cpu_axi_table, 0,
229 REG_CLOCK_CONFIG_CR),
230 CLK_CFG(CLK_AXI, "clk_axi", "clk_msspll", 2, 2, mpfs_div_cpu_axi_table, 0,
231 REG_CLOCK_CONFIG_CR),
232 CLK_CFG(CLK_AHB, "clk_ahb", "clk_msspll", 4, 2, mpfs_div_ahb_table, 0,
233 REG_CLOCK_CONFIG_CR),
234 {
235 .id = CLK_RTCREF,
236 .cfg.shift = 0,
237 .cfg.width = 12,
238 .cfg.table = mpfs_div_rtcref_table,
239 .reg_offset = REG_RTC_CLOCK_CR,
240 .cfg.flags = CLK_DIVIDER_ONE_BASED,
241 .cfg.hw.init =
242 CLK_HW_INIT_PARENTS_DATA("clk_rtcref", mpfs_ext_ref, &clk_divider_ops, 0),
243 }
244};
245
246static int mpfs_clk_register_cfgs(struct device *dev, struct mpfs_cfg_hw_clock *cfg_hws,
247 unsigned int num_clks, struct mpfs_clock_data *data)
248{
249 unsigned int i, id;
250 int ret;
251
252 for (i = 0; i < num_clks; i++) {
253 struct mpfs_cfg_hw_clock *cfg_hw = &cfg_hws[i];
254
255 cfg_hw->cfg.reg = data->base + cfg_hw->reg_offset;
256 ret = devm_clk_hw_register(dev, &cfg_hw->cfg.hw);
257 if (ret)
258 return dev_err_probe(dev, ret, "failed to register clock id: %d\n",
259 cfg_hw->id);
260
261 id = cfg_hw->id;
262 data->hw_data.hws[id] = &cfg_hw->cfg.hw;
263 }
264
265 return 0;
266}
267
268/*
269 * peripheral clocks - devices connected to axi or ahb buses.
270 */
271
272#define CLK_PERIPH(_id, _name, _parent, _shift, _flags) { \
273 .id = _id, \
274 .periph.bit_idx = _shift, \
275 .periph.hw.init = CLK_HW_INIT_HW(_name, _parent, &clk_gate_ops, \
276 _flags), \
277 .periph.lock = &mpfs_clk_lock, \
278}
279
280#define PARENT_CLK(PARENT) (&mpfs_cfg_clks[CLK_##PARENT##_OFFSET].cfg.hw)
281
282/*
283 * Critical clocks:
284 * - CLK_ENVM: reserved by hart software services (hss) superloop monitor/m mode interrupt
285 * trap handler
286 * - CLK_MMUART0: reserved by the hss
287 * - CLK_DDRC: provides clock to the ddr subsystem
288 * - CLK_RTC: the onboard RTC's AHB bus clock must be kept running as the rtc will stop
289 * if the AHB interface clock is disabled
290 * - CLK_FICx: these provide the processor side clocks to the "FIC" (Fabric InterConnect)
291 * clock domain crossers which provide the interface to the FPGA fabric. Disabling them
292 * causes the FPGA fabric to go into reset.
293 * - CLK_ATHENA: The athena clock is FIC4, which is reserved for the Athena TeraFire.
294 */
295
296static struct mpfs_periph_hw_clock mpfs_periph_clks[] = {
297 CLK_PERIPH(CLK_ENVM, "clk_periph_envm", PARENT_CLK(AHB), 0, CLK_IS_CRITICAL),
298 CLK_PERIPH(CLK_MAC0, "clk_periph_mac0", PARENT_CLK(AHB), 1, 0),
299 CLK_PERIPH(CLK_MAC1, "clk_periph_mac1", PARENT_CLK(AHB), 2, 0),
300 CLK_PERIPH(CLK_MMC, "clk_periph_mmc", PARENT_CLK(AHB), 3, 0),
301 CLK_PERIPH(CLK_TIMER, "clk_periph_timer", PARENT_CLK(RTCREF), 4, 0),
302 CLK_PERIPH(CLK_MMUART0, "clk_periph_mmuart0", PARENT_CLK(AHB), 5, CLK_IS_CRITICAL),
303 CLK_PERIPH(CLK_MMUART1, "clk_periph_mmuart1", PARENT_CLK(AHB), 6, 0),
304 CLK_PERIPH(CLK_MMUART2, "clk_periph_mmuart2", PARENT_CLK(AHB), 7, 0),
305 CLK_PERIPH(CLK_MMUART3, "clk_periph_mmuart3", PARENT_CLK(AHB), 8, 0),
306 CLK_PERIPH(CLK_MMUART4, "clk_periph_mmuart4", PARENT_CLK(AHB), 9, 0),
307 CLK_PERIPH(CLK_SPI0, "clk_periph_spi0", PARENT_CLK(AHB), 10, 0),
308 CLK_PERIPH(CLK_SPI1, "clk_periph_spi1", PARENT_CLK(AHB), 11, 0),
309 CLK_PERIPH(CLK_I2C0, "clk_periph_i2c0", PARENT_CLK(AHB), 12, 0),
310 CLK_PERIPH(CLK_I2C1, "clk_periph_i2c1", PARENT_CLK(AHB), 13, 0),
311 CLK_PERIPH(CLK_CAN0, "clk_periph_can0", PARENT_CLK(AHB), 14, 0),
312 CLK_PERIPH(CLK_CAN1, "clk_periph_can1", PARENT_CLK(AHB), 15, 0),
313 CLK_PERIPH(CLK_USB, "clk_periph_usb", PARENT_CLK(AHB), 16, 0),
314 CLK_PERIPH(CLK_RTC, "clk_periph_rtc", PARENT_CLK(AHB), 18, CLK_IS_CRITICAL),
315 CLK_PERIPH(CLK_QSPI, "clk_periph_qspi", PARENT_CLK(AHB), 19, 0),
316 CLK_PERIPH(CLK_GPIO0, "clk_periph_gpio0", PARENT_CLK(AHB), 20, 0),
317 CLK_PERIPH(CLK_GPIO1, "clk_periph_gpio1", PARENT_CLK(AHB), 21, 0),
318 CLK_PERIPH(CLK_GPIO2, "clk_periph_gpio2", PARENT_CLK(AHB), 22, 0),
319 CLK_PERIPH(CLK_DDRC, "clk_periph_ddrc", PARENT_CLK(AHB), 23, CLK_IS_CRITICAL),
320 CLK_PERIPH(CLK_FIC0, "clk_periph_fic0", PARENT_CLK(AXI), 24, CLK_IS_CRITICAL),
321 CLK_PERIPH(CLK_FIC1, "clk_periph_fic1", PARENT_CLK(AXI), 25, CLK_IS_CRITICAL),
322 CLK_PERIPH(CLK_FIC2, "clk_periph_fic2", PARENT_CLK(AXI), 26, CLK_IS_CRITICAL),
323 CLK_PERIPH(CLK_FIC3, "clk_periph_fic3", PARENT_CLK(AXI), 27, CLK_IS_CRITICAL),
324 CLK_PERIPH(CLK_ATHENA, "clk_periph_athena", PARENT_CLK(AXI), 28, CLK_IS_CRITICAL),
325 CLK_PERIPH(CLK_CFM, "clk_periph_cfm", PARENT_CLK(AHB), 29, 0),
326};
327
328static int mpfs_clk_register_periphs(struct device *dev, struct mpfs_periph_hw_clock *periph_hws,
329 int num_clks, struct mpfs_clock_data *data)
330{
331 unsigned int i, id;
332 int ret;
333
334 for (i = 0; i < num_clks; i++) {
335 struct mpfs_periph_hw_clock *periph_hw = &periph_hws[i];
336
337 periph_hw->periph.reg = data->base + REG_SUBBLK_CLOCK_CR;
338 ret = devm_clk_hw_register(dev, &periph_hw->periph.hw);
339 if (ret)
340 return dev_err_probe(dev, ret, "failed to register clock id: %d\n",
341 periph_hw->id);
342
343 id = periph_hws[i].id;
344 data->hw_data.hws[id] = &periph_hw->periph.hw;
345 }
346
347 return 0;
348}
349
350/*
351 * Peripheral clock resets
352 */
353
354#if IS_ENABLED(CONFIG_RESET_CONTROLLER)
355
356u32 mpfs_reset_read(struct device *dev)
357{
358 struct mpfs_clock_data *clock_data = dev_get_drvdata(dev->parent);
359
360 return readl_relaxed(clock_data->base + REG_SUBBLK_RESET_CR);
361}
362EXPORT_SYMBOL_NS_GPL(mpfs_reset_read, MCHP_CLK_MPFS);
363
364void mpfs_reset_write(struct device *dev, u32 val)
365{
366 struct mpfs_clock_data *clock_data = dev_get_drvdata(dev->parent);
367
368 writel_relaxed(val, clock_data->base + REG_SUBBLK_RESET_CR);
369}
370EXPORT_SYMBOL_NS_GPL(mpfs_reset_write, MCHP_CLK_MPFS);
371
372static void mpfs_reset_unregister_adev(void *_adev)
373{
374 struct auxiliary_device *adev = _adev;
375
376 auxiliary_device_delete(adev);
377}
378
379static void mpfs_reset_adev_release(struct device *dev)
380{
381 struct auxiliary_device *adev = to_auxiliary_dev(dev);
382
383 auxiliary_device_uninit(adev);
384
385 kfree(adev);
386}
387
388static struct auxiliary_device *mpfs_reset_adev_alloc(struct mpfs_clock_data *clk_data)
389{
390 struct auxiliary_device *adev;
391 int ret;
392
393 adev = kzalloc(sizeof(*adev), GFP_KERNEL);
394 if (!adev)
395 return ERR_PTR(-ENOMEM);
396
397 adev->name = "reset-mpfs";
398 adev->dev.parent = clk_data->dev;
399 adev->dev.release = mpfs_reset_adev_release;
400 adev->id = 666u;
401
402 ret = auxiliary_device_init(adev);
403 if (ret) {
404 kfree(adev);
405 return ERR_PTR(ret);
406 }
407
408 return adev;
409}
410
411static int mpfs_reset_controller_register(struct mpfs_clock_data *clk_data)
412{
413 struct auxiliary_device *adev;
414 int ret;
415
416 adev = mpfs_reset_adev_alloc(clk_data);
417 if (IS_ERR(adev))
418 return PTR_ERR(adev);
419
420 ret = auxiliary_device_add(adev);
421 if (ret) {
422 auxiliary_device_uninit(adev);
423 return ret;
424 }
425
426 return devm_add_action_or_reset(clk_data->dev, mpfs_reset_unregister_adev, adev);
427}
428
429#else /* !CONFIG_RESET_CONTROLLER */
430
431static int mpfs_reset_controller_register(struct mpfs_clock_data *clk_data)
432{
433 return 0;
434}
435
436#endif /* !CONFIG_RESET_CONTROLLER */
437
438static int mpfs_clk_probe(struct platform_device *pdev)
439{
440 struct device *dev = &pdev->dev;
441 struct mpfs_clock_data *clk_data;
442 unsigned int num_clks;
443 int ret;
444
445 /* CLK_RESERVED is not part of clock arrays, so add 1 */
446 num_clks = ARRAY_SIZE(mpfs_msspll_clks) + ARRAY_SIZE(mpfs_cfg_clks)
447 + ARRAY_SIZE(mpfs_periph_clks) + 1;
448
449 clk_data = devm_kzalloc(dev, struct_size(clk_data, hw_data.hws, num_clks), GFP_KERNEL);
450 if (!clk_data)
451 return -ENOMEM;
452
453 clk_data->base = devm_platform_ioremap_resource(pdev, 0);
454 if (IS_ERR(clk_data->base))
455 return PTR_ERR(clk_data->base);
456
457 clk_data->msspll_base = devm_platform_ioremap_resource(pdev, 1);
458 if (IS_ERR(clk_data->msspll_base))
459 return PTR_ERR(clk_data->msspll_base);
460
461 clk_data->hw_data.num = num_clks;
462 clk_data->dev = dev;
463 dev_set_drvdata(dev, clk_data);
464
465 ret = mpfs_clk_register_mssplls(dev, mpfs_msspll_clks, ARRAY_SIZE(mpfs_msspll_clks),
466 clk_data);
467 if (ret)
468 return ret;
469
470 ret = mpfs_clk_register_cfgs(dev, mpfs_cfg_clks, ARRAY_SIZE(mpfs_cfg_clks), clk_data);
471 if (ret)
472 return ret;
473
474 ret = mpfs_clk_register_periphs(dev, mpfs_periph_clks, ARRAY_SIZE(mpfs_periph_clks),
475 clk_data);
476 if (ret)
477 return ret;
478
479 ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, &clk_data->hw_data);
480 if (ret)
481 return ret;
482
483 return mpfs_reset_controller_register(clk_data);
484}
485
486static const struct of_device_id mpfs_clk_of_match_table[] = {
487 { .compatible = "microchip,mpfs-clkcfg", },
488 {}
489};
490MODULE_DEVICE_TABLE(of, mpfs_clk_of_match_table);
491
492static struct platform_driver mpfs_clk_driver = {
493 .probe = mpfs_clk_probe,
494 .driver = {
495 .name = "microchip-mpfs-clkcfg",
496 .of_match_table = mpfs_clk_of_match_table,
497 },
498};
499
500static int __init clk_mpfs_init(void)
501{
502 return platform_driver_register(&mpfs_clk_driver);
503}
504core_initcall(clk_mpfs_init);
505
506static void __exit clk_mpfs_exit(void)
507{
508 platform_driver_unregister(&mpfs_clk_driver);
509}
510module_exit(clk_mpfs_exit);
511
512MODULE_DESCRIPTION("Microchip PolarFire SoC Clock Driver");
513MODULE_AUTHOR("Padmarao Begari <padmarao.begari@microchip.com>");
514MODULE_AUTHOR("Daire McNamara <daire.mcnamara@microchip.com>");
515MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>");
516MODULE_LICENSE("GPL");