1 /*
2 * Synopsys HSDK SDP Generic PLL clock driver
3 *
4 * Copyright (C) 2017 Synopsys
5 *
6 * This file is licensed under the terms of the GNU General Public
7 * License version 2. This program is licensed "as is" without any
8 * warranty of any kind, whether express or implied.
9 */
10
11 #include <linux/clk-provider.h>
12 #include <linux/delay.h>
13 #include <linux/device.h>
14 #include <linux/err.h>
15 #include <linux/of.h>
16 #include <linux/of_address.h>
17 #include <linux/of_device.h>
18 #include <linux/platform_device.h>
19 #include <linux/slab.h>
20
21 #define CGU_PLL_CTRL 0x000 /* ARC PLL control register */
22 #define CGU_PLL_STATUS 0x004 /* ARC PLL status register */
23 #define CGU_PLL_FMEAS 0x008 /* ARC PLL frequency measurement register */
24 #define CGU_PLL_MON 0x00C /* ARC PLL monitor register */
25
26 #define CGU_PLL_CTRL_ODIV_SHIFT 2
27 #define CGU_PLL_CTRL_IDIV_SHIFT 4
28 #define CGU_PLL_CTRL_FBDIV_SHIFT 9
29 #define CGU_PLL_CTRL_BAND_SHIFT 20
30
31 #define CGU_PLL_CTRL_ODIV_MASK GENMASK(3, CGU_PLL_CTRL_ODIV_SHIFT)
32 #define CGU_PLL_CTRL_IDIV_MASK GENMASK(8, CGU_PLL_CTRL_IDIV_SHIFT)
33 #define CGU_PLL_CTRL_FBDIV_MASK GENMASK(15, CGU_PLL_CTRL_FBDIV_SHIFT)
34
35 #define CGU_PLL_CTRL_PD BIT(0)
36 #define CGU_PLL_CTRL_BYPASS BIT(1)
37
38 #define CGU_PLL_STATUS_LOCK BIT(0)
39 #define CGU_PLL_STATUS_ERR BIT(1)
40
41 #define HSDK_PLL_MAX_LOCK_TIME 100 /* 100 us */
42
43 #define CGU_PLL_SOURCE_MAX 1
44
45 #define CORE_IF_CLK_THRESHOLD_HZ 500000000
46 #define CREG_CORE_IF_CLK_DIV_1 0x0
47 #define CREG_CORE_IF_CLK_DIV_2 0x1
48
49 struct hsdk_pll_cfg {
50 u32 rate;
51 u32 idiv;
52 u32 fbdiv;
53 u32 odiv;
54 u32 band;
55 };
56
57 static const struct hsdk_pll_cfg asdt_pll_cfg[] = {
58 { 100000000, 0, 11, 3, 0 },
59 { 133000000, 0, 15, 3, 0 },
60 { 200000000, 1, 47, 3, 0 },
61 { 233000000, 1, 27, 2, 0 },
62 { 300000000, 1, 35, 2, 0 },
63 { 333000000, 1, 39, 2, 0 },
64 { 400000000, 1, 47, 2, 0 },
65 { 500000000, 0, 14, 1, 0 },
66 { 600000000, 0, 17, 1, 0 },
67 { 700000000, 0, 20, 1, 0 },
68 { 800000000, 0, 23, 1, 0 },
69 { 900000000, 1, 26, 0, 0 },
70 { 1000000000, 1, 29, 0, 0 },
71 { 1100000000, 1, 32, 0, 0 },
72 { 1200000000, 1, 35, 0, 0 },
73 { 1300000000, 1, 38, 0, 0 },
74 { 1400000000, 1, 41, 0, 0 },
75 { 1500000000, 1, 44, 0, 0 },
76 { 1600000000, 1, 47, 0, 0 },
77 {}
78 };
79
80 static const struct hsdk_pll_cfg hdmi_pll_cfg[] = {
81 { 297000000, 0, 21, 2, 0 },
82 { 540000000, 0, 19, 1, 0 },
83 { 594000000, 0, 21, 1, 0 },
84 {}
85 };
86
87 struct hsdk_pll_clk {
88 struct clk_hw hw;
89 void __iomem *regs;
90 void __iomem *spec_regs;
91 const struct hsdk_pll_devdata *pll_devdata;
92 struct device *dev;
93 };
94
95 struct hsdk_pll_devdata {
96 const struct hsdk_pll_cfg *pll_cfg;
97 int (*update_rate)(struct hsdk_pll_clk *clk, unsigned long rate,
98 const struct hsdk_pll_cfg *cfg);
99 };
100
101 static int hsdk_pll_core_update_rate(struct hsdk_pll_clk *, unsigned long,
102 const struct hsdk_pll_cfg *);
103 static int hsdk_pll_comm_update_rate(struct hsdk_pll_clk *, unsigned long,
104 const struct hsdk_pll_cfg *);
105
106 static const struct hsdk_pll_devdata core_pll_devdata = {
107 .pll_cfg = asdt_pll_cfg,
108 .update_rate = hsdk_pll_core_update_rate,
109 };
110
111 static const struct hsdk_pll_devdata sdt_pll_devdata = {
112 .pll_cfg = asdt_pll_cfg,
113 .update_rate = hsdk_pll_comm_update_rate,
114 };
115
116 static const struct hsdk_pll_devdata hdmi_pll_devdata = {
117 .pll_cfg = hdmi_pll_cfg,
118 .update_rate = hsdk_pll_comm_update_rate,
119 };
120
hsdk_pll_write(struct hsdk_pll_clk * clk,u32 reg,u32 val)121 static inline void hsdk_pll_write(struct hsdk_pll_clk *clk, u32 reg, u32 val)
122 {
123 iowrite32(val, clk->regs + reg);
124 }
125
hsdk_pll_read(struct hsdk_pll_clk * clk,u32 reg)126 static inline u32 hsdk_pll_read(struct hsdk_pll_clk *clk, u32 reg)
127 {
128 return ioread32(clk->regs + reg);
129 }
130
hsdk_pll_set_cfg(struct hsdk_pll_clk * clk,const struct hsdk_pll_cfg * cfg)131 static inline void hsdk_pll_set_cfg(struct hsdk_pll_clk *clk,
132 const struct hsdk_pll_cfg *cfg)
133 {
134 u32 val = 0;
135
136 /* Powerdown and Bypass bits should be cleared */
137 val |= cfg->idiv << CGU_PLL_CTRL_IDIV_SHIFT;
138 val |= cfg->fbdiv << CGU_PLL_CTRL_FBDIV_SHIFT;
139 val |= cfg->odiv << CGU_PLL_CTRL_ODIV_SHIFT;
140 val |= cfg->band << CGU_PLL_CTRL_BAND_SHIFT;
141
142 dev_dbg(clk->dev, "write configuration: %#x\n", val);
143
144 hsdk_pll_write(clk, CGU_PLL_CTRL, val);
145 }
146
hsdk_pll_is_locked(struct hsdk_pll_clk * clk)147 static inline bool hsdk_pll_is_locked(struct hsdk_pll_clk *clk)
148 {
149 return !!(hsdk_pll_read(clk, CGU_PLL_STATUS) & CGU_PLL_STATUS_LOCK);
150 }
151
hsdk_pll_is_err(struct hsdk_pll_clk * clk)152 static inline bool hsdk_pll_is_err(struct hsdk_pll_clk *clk)
153 {
154 return !!(hsdk_pll_read(clk, CGU_PLL_STATUS) & CGU_PLL_STATUS_ERR);
155 }
156
to_hsdk_pll_clk(struct clk_hw * hw)157 static inline struct hsdk_pll_clk *to_hsdk_pll_clk(struct clk_hw *hw)
158 {
159 return container_of(hw, struct hsdk_pll_clk, hw);
160 }
161
hsdk_pll_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)162 static unsigned long hsdk_pll_recalc_rate(struct clk_hw *hw,
163 unsigned long parent_rate)
164 {
165 u32 val;
166 u64 rate;
167 u32 idiv, fbdiv, odiv;
168 struct hsdk_pll_clk *clk = to_hsdk_pll_clk(hw);
169
170 val = hsdk_pll_read(clk, CGU_PLL_CTRL);
171
172 dev_dbg(clk->dev, "current configuration: %#x\n", val);
173
174 /* Check if PLL is disabled */
175 if (val & CGU_PLL_CTRL_PD)
176 return 0;
177
178 /* Check if PLL is bypassed */
179 if (val & CGU_PLL_CTRL_BYPASS)
180 return parent_rate;
181
182 /* input divider = reg.idiv + 1 */
183 idiv = 1 + ((val & CGU_PLL_CTRL_IDIV_MASK) >> CGU_PLL_CTRL_IDIV_SHIFT);
184 /* fb divider = 2*(reg.fbdiv + 1) */
185 fbdiv = 2 * (1 + ((val & CGU_PLL_CTRL_FBDIV_MASK) >> CGU_PLL_CTRL_FBDIV_SHIFT));
186 /* output divider = 2^(reg.odiv) */
187 odiv = 1 << ((val & CGU_PLL_CTRL_ODIV_MASK) >> CGU_PLL_CTRL_ODIV_SHIFT);
188
189 rate = (u64)parent_rate * fbdiv;
190 do_div(rate, idiv * odiv);
191
192 return rate;
193 }
194
hsdk_pll_round_rate(struct clk_hw * hw,unsigned long rate,unsigned long * prate)195 static long hsdk_pll_round_rate(struct clk_hw *hw, unsigned long rate,
196 unsigned long *prate)
197 {
198 int i;
199 unsigned long best_rate;
200 struct hsdk_pll_clk *clk = to_hsdk_pll_clk(hw);
201 const struct hsdk_pll_cfg *pll_cfg = clk->pll_devdata->pll_cfg;
202
203 if (pll_cfg[0].rate == 0)
204 return -EINVAL;
205
206 best_rate = pll_cfg[0].rate;
207
208 for (i = 1; pll_cfg[i].rate != 0; i++) {
209 if (abs(rate - pll_cfg[i].rate) < abs(rate - best_rate))
210 best_rate = pll_cfg[i].rate;
211 }
212
213 dev_dbg(clk->dev, "chosen best rate: %lu\n", best_rate);
214
215 return best_rate;
216 }
217
hsdk_pll_comm_update_rate(struct hsdk_pll_clk * clk,unsigned long rate,const struct hsdk_pll_cfg * cfg)218 static int hsdk_pll_comm_update_rate(struct hsdk_pll_clk *clk,
219 unsigned long rate,
220 const struct hsdk_pll_cfg *cfg)
221 {
222 hsdk_pll_set_cfg(clk, cfg);
223
224 /*
225 * Wait until CGU relocks and check error status.
226 * If after timeout CGU is unlocked yet return error.
227 */
228 udelay(HSDK_PLL_MAX_LOCK_TIME);
229 if (!hsdk_pll_is_locked(clk))
230 return -ETIMEDOUT;
231
232 if (hsdk_pll_is_err(clk))
233 return -EINVAL;
234
235 return 0;
236 }
237
hsdk_pll_core_update_rate(struct hsdk_pll_clk * clk,unsigned long rate,const struct hsdk_pll_cfg * cfg)238 static int hsdk_pll_core_update_rate(struct hsdk_pll_clk *clk,
239 unsigned long rate,
240 const struct hsdk_pll_cfg *cfg)
241 {
242 /*
243 * When core clock exceeds 500MHz, the divider for the interface
244 * clock must be programmed to div-by-2.
245 */
246 if (rate > CORE_IF_CLK_THRESHOLD_HZ)
247 iowrite32(CREG_CORE_IF_CLK_DIV_2, clk->spec_regs);
248
249 hsdk_pll_set_cfg(clk, cfg);
250
251 /*
252 * Wait until CGU relocks and check error status.
253 * If after timeout CGU is unlocked yet return error.
254 */
255 udelay(HSDK_PLL_MAX_LOCK_TIME);
256 if (!hsdk_pll_is_locked(clk))
257 return -ETIMEDOUT;
258
259 if (hsdk_pll_is_err(clk))
260 return -EINVAL;
261
262 /*
263 * Program divider to div-by-1 if we succesfuly set core clock below
264 * 500MHz threshold.
265 */
266 if (rate <= CORE_IF_CLK_THRESHOLD_HZ)
267 iowrite32(CREG_CORE_IF_CLK_DIV_1, clk->spec_regs);
268
269 return 0;
270 }
271
hsdk_pll_set_rate(struct clk_hw * hw,unsigned long rate,unsigned long parent_rate)272 static int hsdk_pll_set_rate(struct clk_hw *hw, unsigned long rate,
273 unsigned long parent_rate)
274 {
275 int i;
276 struct hsdk_pll_clk *clk = to_hsdk_pll_clk(hw);
277 const struct hsdk_pll_cfg *pll_cfg = clk->pll_devdata->pll_cfg;
278
279 for (i = 0; pll_cfg[i].rate != 0; i++) {
280 if (pll_cfg[i].rate == rate) {
281 return clk->pll_devdata->update_rate(clk, rate,
282 &pll_cfg[i]);
283 }
284 }
285
286 dev_err(clk->dev, "invalid rate=%ld, parent_rate=%ld\n", rate,
287 parent_rate);
288
289 return -EINVAL;
290 }
291
292 static const struct clk_ops hsdk_pll_ops = {
293 .recalc_rate = hsdk_pll_recalc_rate,
294 .round_rate = hsdk_pll_round_rate,
295 .set_rate = hsdk_pll_set_rate,
296 };
297
hsdk_pll_clk_probe(struct platform_device * pdev)298 static int hsdk_pll_clk_probe(struct platform_device *pdev)
299 {
300 int ret;
301 struct resource *mem;
302 const char *parent_name;
303 unsigned int num_parents;
304 struct hsdk_pll_clk *pll_clk;
305 struct clk_init_data init = { };
306 struct device *dev = &pdev->dev;
307
308 pll_clk = devm_kzalloc(dev, sizeof(*pll_clk), GFP_KERNEL);
309 if (!pll_clk)
310 return -ENOMEM;
311
312 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
313 pll_clk->regs = devm_ioremap_resource(dev, mem);
314 if (IS_ERR(pll_clk->regs))
315 return PTR_ERR(pll_clk->regs);
316
317 init.name = dev->of_node->name;
318 init.ops = &hsdk_pll_ops;
319 parent_name = of_clk_get_parent_name(dev->of_node, 0);
320 init.parent_names = &parent_name;
321 num_parents = of_clk_get_parent_count(dev->of_node);
322 if (num_parents == 0 || num_parents > CGU_PLL_SOURCE_MAX) {
323 dev_err(dev, "wrong clock parents number: %u\n", num_parents);
324 return -EINVAL;
325 }
326 init.num_parents = num_parents;
327
328 pll_clk->hw.init = &init;
329 pll_clk->dev = dev;
330 pll_clk->pll_devdata = of_device_get_match_data(dev);
331
332 if (!pll_clk->pll_devdata) {
333 dev_err(dev, "No OF match data provided\n");
334 return -EINVAL;
335 }
336
337 ret = devm_clk_hw_register(dev, &pll_clk->hw);
338 if (ret) {
339 dev_err(dev, "failed to register %s clock\n", init.name);
340 return ret;
341 }
342
343 return of_clk_add_hw_provider(dev->of_node, of_clk_hw_simple_get,
344 &pll_clk->hw);
345 }
346
hsdk_pll_clk_remove(struct platform_device * pdev)347 static int hsdk_pll_clk_remove(struct platform_device *pdev)
348 {
349 of_clk_del_provider(pdev->dev.of_node);
350 return 0;
351 }
352
of_hsdk_pll_clk_setup(struct device_node * node)353 static void __init of_hsdk_pll_clk_setup(struct device_node *node)
354 {
355 int ret;
356 const char *parent_name;
357 unsigned int num_parents;
358 struct hsdk_pll_clk *pll_clk;
359 struct clk_init_data init = { };
360
361 pll_clk = kzalloc(sizeof(*pll_clk), GFP_KERNEL);
362 if (!pll_clk)
363 return;
364
365 pll_clk->regs = of_iomap(node, 0);
366 if (!pll_clk->regs) {
367 pr_err("failed to map pll registers\n");
368 goto err_free_pll_clk;
369 }
370
371 pll_clk->spec_regs = of_iomap(node, 1);
372 if (!pll_clk->spec_regs) {
373 pr_err("failed to map pll registers\n");
374 goto err_unmap_comm_regs;
375 }
376
377 init.name = node->name;
378 init.ops = &hsdk_pll_ops;
379 parent_name = of_clk_get_parent_name(node, 0);
380 init.parent_names = &parent_name;
381 num_parents = of_clk_get_parent_count(node);
382 if (num_parents > CGU_PLL_SOURCE_MAX) {
383 pr_err("too much clock parents: %u\n", num_parents);
384 goto err_unmap_spec_regs;
385 }
386 init.num_parents = num_parents;
387
388 pll_clk->hw.init = &init;
389 pll_clk->pll_devdata = &core_pll_devdata;
390
391 ret = clk_hw_register(NULL, &pll_clk->hw);
392 if (ret) {
393 pr_err("failed to register %s clock\n", node->name);
394 goto err_unmap_spec_regs;
395 }
396
397 ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, &pll_clk->hw);
398 if (ret) {
399 pr_err("failed to add hw provider for %s clock\n", node->name);
400 goto err_unmap_spec_regs;
401 }
402
403 return;
404
405 err_unmap_spec_regs:
406 iounmap(pll_clk->spec_regs);
407 err_unmap_comm_regs:
408 iounmap(pll_clk->regs);
409 err_free_pll_clk:
410 kfree(pll_clk);
411 }
412
413 /* Core PLL needed early for ARC cpus timers */
414 CLK_OF_DECLARE(hsdk_pll_clock, "snps,hsdk-core-pll-clock",
415 of_hsdk_pll_clk_setup);
416
417 static const struct of_device_id hsdk_pll_clk_id[] = {
418 { .compatible = "snps,hsdk-gp-pll-clock", .data = &sdt_pll_devdata},
419 { .compatible = "snps,hsdk-hdmi-pll-clock", .data = &hdmi_pll_devdata},
420 { }
421 };
422
423 static struct platform_driver hsdk_pll_clk_driver = {
424 .driver = {
425 .name = "hsdk-gp-pll-clock",
426 .of_match_table = hsdk_pll_clk_id,
427 },
428 .probe = hsdk_pll_clk_probe,
429 .remove = hsdk_pll_clk_remove,
430 };
431 builtin_platform_driver(hsdk_pll_clk_driver);
432
