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/clk-provider.h>
8 #include <linux/io.h>
9 #include <linux/module.h>
10 #include <linux/platform_device.h>
11 #include <dt-bindings/clock/microchip,mpfs-clock.h>
12 #include <soc/microchip/mpfs.h>
13
14 /* address offset of control registers */
15 #define REG_MSSPLL_REF_CR 0x08u
16 #define REG_MSSPLL_POSTDIV01_CR 0x10u
17 #define REG_MSSPLL_POSTDIV23_CR 0x14u
18 #define REG_MSSPLL_SSCG_2_CR 0x2Cu
19 #define REG_CLOCK_CONFIG_CR 0x08u
20 #define REG_RTC_CLOCK_CR 0x0Cu
21 #define REG_SUBBLK_CLOCK_CR 0x84u
22 #define REG_SUBBLK_RESET_CR 0x88u
23
24 #define MSSPLL_FBDIV_SHIFT 0x00u
25 #define MSSPLL_FBDIV_WIDTH 0x0Cu
26 #define MSSPLL_REFDIV_SHIFT 0x08u
27 #define MSSPLL_REFDIV_WIDTH 0x06u
28 #define MSSPLL_POSTDIV02_SHIFT 0x08u
29 #define MSSPLL_POSTDIV13_SHIFT 0x18u
30 #define MSSPLL_POSTDIV_WIDTH 0x07u
31 #define MSSPLL_FIXED_DIV 4u
32
33 /*
34 * This clock ID is defined here, rather than the binding headers, as it is an
35 * internal clock only, and therefore has no consumers in other peripheral
36 * blocks.
37 */
38 #define CLK_MSSPLL_INTERNAL 38u
39
40 struct mpfs_clock_data {
41 struct device *dev;
42 void __iomem *base;
43 void __iomem *msspll_base;
44 struct clk_hw_onecell_data hw_data;
45 };
46
47 struct mpfs_msspll_hw_clock {
48 void __iomem *base;
49 struct clk_hw hw;
50 struct clk_init_data init;
51 unsigned int id;
52 u32 reg_offset;
53 u32 shift;
54 u32 width;
55 u32 flags;
56 };
57
58 #define to_mpfs_msspll_clk(_hw) container_of(_hw, struct mpfs_msspll_hw_clock, hw)
59
60 struct mpfs_msspll_out_hw_clock {
61 void __iomem *base;
62 struct clk_divider output;
63 struct clk_init_data init;
64 unsigned int id;
65 u32 reg_offset;
66 };
67
68 #define to_mpfs_msspll_out_clk(_hw) container_of(_hw, struct mpfs_msspll_out_hw_clock, hw)
69
70 struct mpfs_cfg_hw_clock {
71 struct clk_divider cfg;
72 struct clk_init_data init;
73 unsigned int id;
74 u32 reg_offset;
75 };
76
77 struct mpfs_periph_hw_clock {
78 struct clk_gate periph;
79 unsigned int id;
80 };
81
82 /*
83 * mpfs_clk_lock prevents anything else from writing to the
84 * mpfs clk block while a software locked register is being written.
85 */
86 static DEFINE_SPINLOCK(mpfs_clk_lock);
87
88 static const struct clk_parent_data mpfs_ext_ref[] = {
89 { .index = 0 },
90 };
91
92 static const struct clk_div_table mpfs_div_cpu_axi_table[] = {
93 { 0, 1 }, { 1, 2 }, { 2, 4 }, { 3, 8 },
94 { 0, 0 }
95 };
96
97 static const struct clk_div_table mpfs_div_ahb_table[] = {
98 { 1, 2 }, { 2, 4}, { 3, 8 },
99 { 0, 0 }
100 };
101
102 /*
103 * The only two supported reference clock frequencies for the PolarFire SoC are
104 * 100 and 125 MHz, as the rtc reference is required to be 1 MHz.
105 * It therefore only needs to have divider table entries corresponding to
106 * divide by 100 and 125.
107 */
108 static const struct clk_div_table mpfs_div_rtcref_table[] = {
109 { 100, 100 }, { 125, 125 },
110 { 0, 0 }
111 };
112
113 /*
114 * MSS PLL internal clock
115 */
116
mpfs_clk_msspll_recalc_rate(struct clk_hw * hw,unsigned long prate)117 static unsigned long mpfs_clk_msspll_recalc_rate(struct clk_hw *hw, unsigned long prate)
118 {
119 struct mpfs_msspll_hw_clock *msspll_hw = to_mpfs_msspll_clk(hw);
120 void __iomem *mult_addr = msspll_hw->base + msspll_hw->reg_offset;
121 void __iomem *ref_div_addr = msspll_hw->base + REG_MSSPLL_REF_CR;
122 u32 mult, ref_div;
123
124 mult = readl_relaxed(mult_addr) >> MSSPLL_FBDIV_SHIFT;
125 mult &= clk_div_mask(MSSPLL_FBDIV_WIDTH);
126 ref_div = readl_relaxed(ref_div_addr) >> MSSPLL_REFDIV_SHIFT;
127 ref_div &= clk_div_mask(MSSPLL_REFDIV_WIDTH);
128
129 return prate * mult / (ref_div * MSSPLL_FIXED_DIV);
130 }
131
132 static const struct clk_ops mpfs_clk_msspll_ops = {
133 .recalc_rate = mpfs_clk_msspll_recalc_rate,
134 };
135
136 #define CLK_PLL(_id, _name, _parent, _shift, _width, _flags, _offset) { \
137 .id = _id, \
138 .flags = _flags, \
139 .shift = _shift, \
140 .width = _width, \
141 .reg_offset = _offset, \
142 .hw.init = CLK_HW_INIT_PARENTS_DATA(_name, _parent, &mpfs_clk_msspll_ops, 0), \
143 }
144
145 static struct mpfs_msspll_hw_clock mpfs_msspll_clks[] = {
146 CLK_PLL(CLK_MSSPLL_INTERNAL, "clk_msspll_internal", mpfs_ext_ref, MSSPLL_FBDIV_SHIFT,
147 MSSPLL_FBDIV_WIDTH, 0, REG_MSSPLL_SSCG_2_CR),
148 };
149
mpfs_clk_register_mssplls(struct device * dev,struct mpfs_msspll_hw_clock * msspll_hws,unsigned int num_clks,struct mpfs_clock_data * data)150 static int mpfs_clk_register_mssplls(struct device *dev, struct mpfs_msspll_hw_clock *msspll_hws,
151 unsigned int num_clks, struct mpfs_clock_data *data)
152 {
153 unsigned int i;
154 int ret;
155
156 for (i = 0; i < num_clks; i++) {
157 struct mpfs_msspll_hw_clock *msspll_hw = &msspll_hws[i];
158
159 msspll_hw->base = data->msspll_base;
160 ret = devm_clk_hw_register(dev, &msspll_hw->hw);
161 if (ret)
162 return dev_err_probe(dev, ret, "failed to register msspll id: %d\n",
163 CLK_MSSPLL_INTERNAL);
164
165 data->hw_data.hws[msspll_hw->id] = &msspll_hw->hw;
166 }
167
168 return 0;
169 }
170
171 /*
172 * MSS PLL output clocks
173 */
174
175 #define CLK_PLL_OUT(_id, _name, _parent, _flags, _shift, _width, _offset) { \
176 .id = _id, \
177 .output.shift = _shift, \
178 .output.width = _width, \
179 .output.table = NULL, \
180 .reg_offset = _offset, \
181 .output.flags = _flags, \
182 .output.hw.init = CLK_HW_INIT(_name, _parent, &clk_divider_ops, 0), \
183 .output.lock = &mpfs_clk_lock, \
184 }
185
186 static struct mpfs_msspll_out_hw_clock mpfs_msspll_out_clks[] = {
187 CLK_PLL_OUT(CLK_MSSPLL0, "clk_msspll", "clk_msspll_internal", CLK_DIVIDER_ONE_BASED,
188 MSSPLL_POSTDIV02_SHIFT, MSSPLL_POSTDIV_WIDTH, REG_MSSPLL_POSTDIV01_CR),
189 CLK_PLL_OUT(CLK_MSSPLL1, "clk_msspll1", "clk_msspll_internal", CLK_DIVIDER_ONE_BASED,
190 MSSPLL_POSTDIV13_SHIFT, MSSPLL_POSTDIV_WIDTH, REG_MSSPLL_POSTDIV01_CR),
191 CLK_PLL_OUT(CLK_MSSPLL2, "clk_msspll2", "clk_msspll_internal", CLK_DIVIDER_ONE_BASED,
192 MSSPLL_POSTDIV02_SHIFT, MSSPLL_POSTDIV_WIDTH, REG_MSSPLL_POSTDIV23_CR),
193 CLK_PLL_OUT(CLK_MSSPLL3, "clk_msspll3", "clk_msspll_internal", CLK_DIVIDER_ONE_BASED,
194 MSSPLL_POSTDIV13_SHIFT, MSSPLL_POSTDIV_WIDTH, REG_MSSPLL_POSTDIV23_CR),
195 };
196
mpfs_clk_register_msspll_outs(struct device * dev,struct mpfs_msspll_out_hw_clock * msspll_out_hws,unsigned int num_clks,struct mpfs_clock_data * data)197 static int mpfs_clk_register_msspll_outs(struct device *dev,
198 struct mpfs_msspll_out_hw_clock *msspll_out_hws,
199 unsigned int num_clks, struct mpfs_clock_data *data)
200 {
201 unsigned int i;
202 int ret;
203
204 for (i = 0; i < num_clks; i++) {
205 struct mpfs_msspll_out_hw_clock *msspll_out_hw = &msspll_out_hws[i];
206
207 msspll_out_hw->output.reg = data->msspll_base + msspll_out_hw->reg_offset;
208 ret = devm_clk_hw_register(dev, &msspll_out_hw->output.hw);
209 if (ret)
210 return dev_err_probe(dev, ret, "failed to register msspll out id: %d\n",
211 msspll_out_hw->id);
212
213 data->hw_data.hws[msspll_out_hw->id] = &msspll_out_hw->output.hw;
214 }
215
216 return 0;
217 }
218
219 /*
220 * "CFG" clocks
221 */
222
223 #define CLK_CFG(_id, _name, _parent, _shift, _width, _table, _flags, _offset) { \
224 .id = _id, \
225 .cfg.shift = _shift, \
226 .cfg.width = _width, \
227 .cfg.table = _table, \
228 .reg_offset = _offset, \
229 .cfg.flags = _flags, \
230 .cfg.hw.init = CLK_HW_INIT(_name, _parent, &clk_divider_ops, 0), \
231 .cfg.lock = &mpfs_clk_lock, \
232 }
233
234 #define CLK_CPU_OFFSET 0u
235 #define CLK_AXI_OFFSET 1u
236 #define CLK_AHB_OFFSET 2u
237 #define CLK_RTCREF_OFFSET 3u
238
239 static struct mpfs_cfg_hw_clock mpfs_cfg_clks[] = {
240 CLK_CFG(CLK_CPU, "clk_cpu", "clk_msspll", 0, 2, mpfs_div_cpu_axi_table, 0,
241 REG_CLOCK_CONFIG_CR),
242 CLK_CFG(CLK_AXI, "clk_axi", "clk_msspll", 2, 2, mpfs_div_cpu_axi_table, 0,
243 REG_CLOCK_CONFIG_CR),
244 CLK_CFG(CLK_AHB, "clk_ahb", "clk_msspll", 4, 2, mpfs_div_ahb_table, 0,
245 REG_CLOCK_CONFIG_CR),
246 {
247 .id = CLK_RTCREF,
248 .cfg.shift = 0,
249 .cfg.width = 12,
250 .cfg.table = mpfs_div_rtcref_table,
251 .reg_offset = REG_RTC_CLOCK_CR,
252 .cfg.flags = CLK_DIVIDER_ONE_BASED,
253 .cfg.hw.init =
254 CLK_HW_INIT_PARENTS_DATA("clk_rtcref", mpfs_ext_ref, &clk_divider_ops, 0),
255 }
256 };
257
mpfs_clk_register_cfgs(struct device * dev,struct mpfs_cfg_hw_clock * cfg_hws,unsigned int num_clks,struct mpfs_clock_data * data)258 static int mpfs_clk_register_cfgs(struct device *dev, struct mpfs_cfg_hw_clock *cfg_hws,
259 unsigned int num_clks, struct mpfs_clock_data *data)
260 {
261 unsigned int i, id;
262 int ret;
263
264 for (i = 0; i < num_clks; i++) {
265 struct mpfs_cfg_hw_clock *cfg_hw = &cfg_hws[i];
266
267 cfg_hw->cfg.reg = data->base + cfg_hw->reg_offset;
268 ret = devm_clk_hw_register(dev, &cfg_hw->cfg.hw);
269 if (ret)
270 return dev_err_probe(dev, ret, "failed to register clock id: %d\n",
271 cfg_hw->id);
272
273 id = cfg_hw->id;
274 data->hw_data.hws[id] = &cfg_hw->cfg.hw;
275 }
276
277 return 0;
278 }
279
280 /*
281 * peripheral clocks - devices connected to axi or ahb buses.
282 */
283
284 #define CLK_PERIPH(_id, _name, _parent, _shift, _flags) { \
285 .id = _id, \
286 .periph.bit_idx = _shift, \
287 .periph.hw.init = CLK_HW_INIT_HW(_name, _parent, &clk_gate_ops, \
288 _flags), \
289 .periph.lock = &mpfs_clk_lock, \
290 }
291
292 #define PARENT_CLK(PARENT) (&mpfs_cfg_clks[CLK_##PARENT##_OFFSET].cfg.hw)
293
294 /*
295 * Critical clocks:
296 * - CLK_ENVM: reserved by hart software services (hss) superloop monitor/m mode interrupt
297 * trap handler
298 * - CLK_MMUART0: reserved by the hss
299 * - CLK_DDRC: provides clock to the ddr subsystem
300 * - CLK_RTC: the onboard RTC's AHB bus clock must be kept running as the rtc will stop
301 * if the AHB interface clock is disabled
302 * - CLK_FICx: these provide the processor side clocks to the "FIC" (Fabric InterConnect)
303 * clock domain crossers which provide the interface to the FPGA fabric. Disabling them
304 * causes the FPGA fabric to go into reset.
305 * - CLK_ATHENA: The athena clock is FIC4, which is reserved for the Athena TeraFire.
306 */
307
308 static struct mpfs_periph_hw_clock mpfs_periph_clks[] = {
309 CLK_PERIPH(CLK_ENVM, "clk_periph_envm", PARENT_CLK(AHB), 0, CLK_IS_CRITICAL),
310 CLK_PERIPH(CLK_MAC0, "clk_periph_mac0", PARENT_CLK(AHB), 1, 0),
311 CLK_PERIPH(CLK_MAC1, "clk_periph_mac1", PARENT_CLK(AHB), 2, 0),
312 CLK_PERIPH(CLK_MMC, "clk_periph_mmc", PARENT_CLK(AHB), 3, 0),
313 CLK_PERIPH(CLK_TIMER, "clk_periph_timer", PARENT_CLK(RTCREF), 4, 0),
314 CLK_PERIPH(CLK_MMUART0, "clk_periph_mmuart0", PARENT_CLK(AHB), 5, CLK_IS_CRITICAL),
315 CLK_PERIPH(CLK_MMUART1, "clk_periph_mmuart1", PARENT_CLK(AHB), 6, 0),
316 CLK_PERIPH(CLK_MMUART2, "clk_periph_mmuart2", PARENT_CLK(AHB), 7, 0),
317 CLK_PERIPH(CLK_MMUART3, "clk_periph_mmuart3", PARENT_CLK(AHB), 8, 0),
318 CLK_PERIPH(CLK_MMUART4, "clk_periph_mmuart4", PARENT_CLK(AHB), 9, 0),
319 CLK_PERIPH(CLK_SPI0, "clk_periph_spi0", PARENT_CLK(AHB), 10, 0),
320 CLK_PERIPH(CLK_SPI1, "clk_periph_spi1", PARENT_CLK(AHB), 11, 0),
321 CLK_PERIPH(CLK_I2C0, "clk_periph_i2c0", PARENT_CLK(AHB), 12, 0),
322 CLK_PERIPH(CLK_I2C1, "clk_periph_i2c1", PARENT_CLK(AHB), 13, 0),
323 CLK_PERIPH(CLK_CAN0, "clk_periph_can0", PARENT_CLK(AHB), 14, 0),
324 CLK_PERIPH(CLK_CAN1, "clk_periph_can1", PARENT_CLK(AHB), 15, 0),
325 CLK_PERIPH(CLK_USB, "clk_periph_usb", PARENT_CLK(AHB), 16, 0),
326 CLK_PERIPH(CLK_RTC, "clk_periph_rtc", PARENT_CLK(AHB), 18, CLK_IS_CRITICAL),
327 CLK_PERIPH(CLK_QSPI, "clk_periph_qspi", PARENT_CLK(AHB), 19, 0),
328 CLK_PERIPH(CLK_GPIO0, "clk_periph_gpio0", PARENT_CLK(AHB), 20, 0),
329 CLK_PERIPH(CLK_GPIO1, "clk_periph_gpio1", PARENT_CLK(AHB), 21, 0),
330 CLK_PERIPH(CLK_GPIO2, "clk_periph_gpio2", PARENT_CLK(AHB), 22, 0),
331 CLK_PERIPH(CLK_DDRC, "clk_periph_ddrc", PARENT_CLK(AHB), 23, CLK_IS_CRITICAL),
332 CLK_PERIPH(CLK_FIC0, "clk_periph_fic0", PARENT_CLK(AXI), 24, CLK_IS_CRITICAL),
333 CLK_PERIPH(CLK_FIC1, "clk_periph_fic1", PARENT_CLK(AXI), 25, CLK_IS_CRITICAL),
334 CLK_PERIPH(CLK_FIC2, "clk_periph_fic2", PARENT_CLK(AXI), 26, CLK_IS_CRITICAL),
335 CLK_PERIPH(CLK_FIC3, "clk_periph_fic3", PARENT_CLK(AXI), 27, CLK_IS_CRITICAL),
336 CLK_PERIPH(CLK_ATHENA, "clk_periph_athena", PARENT_CLK(AXI), 28, CLK_IS_CRITICAL),
337 CLK_PERIPH(CLK_CFM, "clk_periph_cfm", PARENT_CLK(AHB), 29, 0),
338 };
339
mpfs_clk_register_periphs(struct device * dev,struct mpfs_periph_hw_clock * periph_hws,int num_clks,struct mpfs_clock_data * data)340 static int mpfs_clk_register_periphs(struct device *dev, struct mpfs_periph_hw_clock *periph_hws,
341 int num_clks, struct mpfs_clock_data *data)
342 {
343 unsigned int i, id;
344 int ret;
345
346 for (i = 0; i < num_clks; i++) {
347 struct mpfs_periph_hw_clock *periph_hw = &periph_hws[i];
348
349 periph_hw->periph.reg = data->base + REG_SUBBLK_CLOCK_CR;
350 ret = devm_clk_hw_register(dev, &periph_hw->periph.hw);
351 if (ret)
352 return dev_err_probe(dev, ret, "failed to register clock id: %d\n",
353 periph_hw->id);
354
355 id = periph_hws[i].id;
356 data->hw_data.hws[id] = &periph_hw->periph.hw;
357 }
358
359 return 0;
360 }
361
mpfs_clk_probe(struct platform_device * pdev)362 static int mpfs_clk_probe(struct platform_device *pdev)
363 {
364 struct device *dev = &pdev->dev;
365 struct mpfs_clock_data *clk_data;
366 unsigned int num_clks;
367 int ret;
368
369 /* CLK_RESERVED is not part of clock arrays, so add 1 */
370 num_clks = ARRAY_SIZE(mpfs_msspll_clks) + ARRAY_SIZE(mpfs_msspll_out_clks)
371 + ARRAY_SIZE(mpfs_cfg_clks) + ARRAY_SIZE(mpfs_periph_clks) + 1;
372
373 clk_data = devm_kzalloc(dev, struct_size(clk_data, hw_data.hws, num_clks), GFP_KERNEL);
374 if (!clk_data)
375 return -ENOMEM;
376
377 clk_data->base = devm_platform_ioremap_resource(pdev, 0);
378 if (IS_ERR(clk_data->base))
379 return PTR_ERR(clk_data->base);
380
381 clk_data->msspll_base = devm_platform_ioremap_resource(pdev, 1);
382 if (IS_ERR(clk_data->msspll_base))
383 return PTR_ERR(clk_data->msspll_base);
384
385 clk_data->hw_data.num = num_clks;
386 clk_data->dev = dev;
387 dev_set_drvdata(dev, clk_data);
388
389 ret = mpfs_clk_register_mssplls(dev, mpfs_msspll_clks, ARRAY_SIZE(mpfs_msspll_clks),
390 clk_data);
391 if (ret)
392 return ret;
393
394 ret = mpfs_clk_register_msspll_outs(dev, mpfs_msspll_out_clks,
395 ARRAY_SIZE(mpfs_msspll_out_clks),
396 clk_data);
397 if (ret)
398 return ret;
399
400 ret = mpfs_clk_register_cfgs(dev, mpfs_cfg_clks, ARRAY_SIZE(mpfs_cfg_clks), clk_data);
401 if (ret)
402 return ret;
403
404 ret = mpfs_clk_register_periphs(dev, mpfs_periph_clks, ARRAY_SIZE(mpfs_periph_clks),
405 clk_data);
406 if (ret)
407 return ret;
408
409 ret = devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get, &clk_data->hw_data);
410 if (ret)
411 return ret;
412
413 return mpfs_reset_controller_register(dev, clk_data->base + REG_SUBBLK_RESET_CR);
414 }
415
416 static const struct of_device_id mpfs_clk_of_match_table[] = {
417 { .compatible = "microchip,mpfs-clkcfg", },
418 {}
419 };
420 MODULE_DEVICE_TABLE(of, mpfs_clk_of_match_table);
421
422 static struct platform_driver mpfs_clk_driver = {
423 .probe = mpfs_clk_probe,
424 .driver = {
425 .name = "microchip-mpfs-clkcfg",
426 .of_match_table = mpfs_clk_of_match_table,
427 },
428 };
429
clk_mpfs_init(void)430 static int __init clk_mpfs_init(void)
431 {
432 return platform_driver_register(&mpfs_clk_driver);
433 }
434 core_initcall(clk_mpfs_init);
435
clk_mpfs_exit(void)436 static void __exit clk_mpfs_exit(void)
437 {
438 platform_driver_unregister(&mpfs_clk_driver);
439 }
440 module_exit(clk_mpfs_exit);
441
442 MODULE_DESCRIPTION("Microchip PolarFire SoC Clock Driver");
443 MODULE_AUTHOR("Padmarao Begari <padmarao.begari@microchip.com>");
444 MODULE_AUTHOR("Daire McNamara <daire.mcnamara@microchip.com>");
445 MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>");
446 MODULE_IMPORT_NS("MCHP_CLK_MPFS");
447