1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright 2013 Emilio López
4 *
5 * Emilio López <emilio@elopez.com.ar>
6 */
7
8 #include <linux/clk.h>
9 #include <linux/clk-provider.h>
10 #include <linux/io.h>
11 #include <linux/of_address.h>
12 #include <linux/platform_device.h>
13 #include <linux/slab.h>
14
15 #include "clk-factors.h"
16
17 /*
18 * sun4i_a10_get_mod0_factors() - calculates m, n factors for MOD0-style clocks
19 * MOD0 rate is calculated as follows
20 * rate = (parent_rate >> p) / (m + 1);
21 */
22
sun4i_a10_get_mod0_factors(struct factors_request * req)23 static void sun4i_a10_get_mod0_factors(struct factors_request *req)
24 {
25 u8 div, calcm, calcp;
26
27 /* These clocks can only divide, so we will never be able to achieve
28 * frequencies higher than the parent frequency */
29 if (req->rate > req->parent_rate)
30 req->rate = req->parent_rate;
31
32 div = DIV_ROUND_UP(req->parent_rate, req->rate);
33
34 if (div < 16)
35 calcp = 0;
36 else if (div / 2 < 16)
37 calcp = 1;
38 else if (div / 4 < 16)
39 calcp = 2;
40 else
41 calcp = 3;
42
43 calcm = DIV_ROUND_UP(div, 1 << calcp);
44
45 req->rate = (req->parent_rate >> calcp) / calcm;
46 req->m = calcm - 1;
47 req->p = calcp;
48 }
49
50 /* user manual says "n" but it's really "p" */
51 static const struct clk_factors_config sun4i_a10_mod0_config = {
52 .mshift = 0,
53 .mwidth = 4,
54 .pshift = 16,
55 .pwidth = 2,
56 };
57
58 static const struct factors_data sun4i_a10_mod0_data = {
59 .enable = 31,
60 .mux = 24,
61 .muxmask = BIT(1) | BIT(0),
62 .table = &sun4i_a10_mod0_config,
63 .getter = sun4i_a10_get_mod0_factors,
64 };
65
66 static DEFINE_SPINLOCK(sun4i_a10_mod0_lock);
67
sun4i_a10_mod0_setup(struct device_node * node)68 static void __init sun4i_a10_mod0_setup(struct device_node *node)
69 {
70 void __iomem *reg;
71
72 reg = of_iomap(node, 0);
73 if (!reg) {
74 /*
75 * This happens with mod0 clk nodes instantiated through
76 * mfd, as those do not have their resources assigned at
77 * CLK_OF_DECLARE time yet, so do not print an error.
78 */
79 return;
80 }
81
82 sunxi_factors_register(node, &sun4i_a10_mod0_data,
83 &sun4i_a10_mod0_lock, reg);
84 }
85 CLK_OF_DECLARE_DRIVER(sun4i_a10_mod0, "allwinner,sun4i-a10-mod0-clk",
86 sun4i_a10_mod0_setup);
87
sun4i_a10_mod0_clk_probe(struct platform_device * pdev)88 static int sun4i_a10_mod0_clk_probe(struct platform_device *pdev)
89 {
90 struct device_node *np = pdev->dev.of_node;
91 void __iomem *reg;
92
93 if (!np)
94 return -ENODEV;
95
96 reg = devm_platform_ioremap_resource(pdev, 0);
97 if (IS_ERR(reg))
98 return PTR_ERR(reg);
99
100 sunxi_factors_register(np, &sun4i_a10_mod0_data,
101 &sun4i_a10_mod0_lock, reg);
102 return 0;
103 }
104
105 static const struct of_device_id sun4i_a10_mod0_clk_dt_ids[] = {
106 { .compatible = "allwinner,sun4i-a10-mod0-clk" },
107 { /* sentinel */ }
108 };
109
110 static struct platform_driver sun4i_a10_mod0_clk_driver = {
111 .driver = {
112 .name = "sun4i-a10-mod0-clk",
113 .of_match_table = sun4i_a10_mod0_clk_dt_ids,
114 },
115 .probe = sun4i_a10_mod0_clk_probe,
116 };
117 builtin_platform_driver(sun4i_a10_mod0_clk_driver);
118
119 static const struct factors_data sun9i_a80_mod0_data __initconst = {
120 .enable = 31,
121 .mux = 24,
122 .muxmask = BIT(3) | BIT(2) | BIT(1) | BIT(0),
123 .table = &sun4i_a10_mod0_config,
124 .getter = sun4i_a10_get_mod0_factors,
125 };
126
sun9i_a80_mod0_setup(struct device_node * node)127 static void __init sun9i_a80_mod0_setup(struct device_node *node)
128 {
129 void __iomem *reg;
130
131 reg = of_io_request_and_map(node, 0, of_node_full_name(node));
132 if (IS_ERR(reg)) {
133 pr_err("Could not get registers for mod0-clk: %pOFn\n",
134 node);
135 return;
136 }
137
138 sunxi_factors_register(node, &sun9i_a80_mod0_data,
139 &sun4i_a10_mod0_lock, reg);
140 }
141 CLK_OF_DECLARE(sun9i_a80_mod0, "allwinner,sun9i-a80-mod0-clk", sun9i_a80_mod0_setup);
142
143 static DEFINE_SPINLOCK(sun5i_a13_mbus_lock);
144
sun5i_a13_mbus_setup(struct device_node * node)145 static void __init sun5i_a13_mbus_setup(struct device_node *node)
146 {
147 void __iomem *reg;
148
149 reg = of_iomap(node, 0);
150 if (!reg) {
151 pr_err("Could not get registers for a13-mbus-clk\n");
152 return;
153 }
154
155 /* The MBUS clocks needs to be always enabled */
156 sunxi_factors_register_critical(node, &sun4i_a10_mod0_data,
157 &sun5i_a13_mbus_lock, reg);
158 }
159 CLK_OF_DECLARE(sun5i_a13_mbus, "allwinner,sun5i-a13-mbus-clk", sun5i_a13_mbus_setup);
160
161 struct mmc_phase {
162 struct clk_hw hw;
163 u8 offset;
164 void __iomem *reg;
165 spinlock_t *lock;
166 };
167
168 #define to_mmc_phase(_hw) container_of(_hw, struct mmc_phase, hw)
169
mmc_get_phase(struct clk_hw * hw)170 static int mmc_get_phase(struct clk_hw *hw)
171 {
172 struct clk *mmc, *mmc_parent, *clk = hw->clk;
173 struct mmc_phase *phase = to_mmc_phase(hw);
174 unsigned int mmc_rate, mmc_parent_rate;
175 u16 step, mmc_div;
176 u32 value;
177 u8 delay;
178
179 value = readl(phase->reg);
180 delay = (value >> phase->offset) & 0x3;
181
182 if (!delay)
183 return 180;
184
185 /* Get the main MMC clock */
186 mmc = clk_get_parent(clk);
187 if (!mmc)
188 return -EINVAL;
189
190 /* And its rate */
191 mmc_rate = clk_get_rate(mmc);
192 if (!mmc_rate)
193 return -EINVAL;
194
195 /* Now, get the MMC parent (most likely some PLL) */
196 mmc_parent = clk_get_parent(mmc);
197 if (!mmc_parent)
198 return -EINVAL;
199
200 /* And its rate */
201 mmc_parent_rate = clk_get_rate(mmc_parent);
202 if (!mmc_parent_rate)
203 return -EINVAL;
204
205 /* Get MMC clock divider */
206 mmc_div = mmc_parent_rate / mmc_rate;
207
208 step = DIV_ROUND_CLOSEST(360, mmc_div);
209 return delay * step;
210 }
211
mmc_set_phase(struct clk_hw * hw,int degrees)212 static int mmc_set_phase(struct clk_hw *hw, int degrees)
213 {
214 struct clk *mmc, *mmc_parent, *clk = hw->clk;
215 struct mmc_phase *phase = to_mmc_phase(hw);
216 unsigned int mmc_rate, mmc_parent_rate;
217 unsigned long flags;
218 u32 value;
219 u8 delay;
220
221 /* Get the main MMC clock */
222 mmc = clk_get_parent(clk);
223 if (!mmc)
224 return -EINVAL;
225
226 /* And its rate */
227 mmc_rate = clk_get_rate(mmc);
228 if (!mmc_rate)
229 return -EINVAL;
230
231 /* Now, get the MMC parent (most likely some PLL) */
232 mmc_parent = clk_get_parent(mmc);
233 if (!mmc_parent)
234 return -EINVAL;
235
236 /* And its rate */
237 mmc_parent_rate = clk_get_rate(mmc_parent);
238 if (!mmc_parent_rate)
239 return -EINVAL;
240
241 if (degrees != 180) {
242 u16 step, mmc_div;
243
244 /* Get MMC clock divider */
245 mmc_div = mmc_parent_rate / mmc_rate;
246
247 /*
248 * We can only outphase the clocks by multiple of the
249 * PLL's period.
250 *
251 * Since the MMC clock in only a divider, and the
252 * formula to get the outphasing in degrees is deg =
253 * 360 * delta / period
254 *
255 * If we simplify this formula, we can see that the
256 * only thing that we're concerned about is the number
257 * of period we want to outphase our clock from, and
258 * the divider set by the MMC clock.
259 */
260 step = DIV_ROUND_CLOSEST(360, mmc_div);
261 delay = DIV_ROUND_CLOSEST(degrees, step);
262 } else {
263 delay = 0;
264 }
265
266 spin_lock_irqsave(phase->lock, flags);
267 value = readl(phase->reg);
268 value &= ~GENMASK(phase->offset + 3, phase->offset);
269 value |= delay << phase->offset;
270 writel(value, phase->reg);
271 spin_unlock_irqrestore(phase->lock, flags);
272
273 return 0;
274 }
275
276 static const struct clk_ops mmc_clk_ops = {
277 .get_phase = mmc_get_phase,
278 .set_phase = mmc_set_phase,
279 };
280
281 /*
282 * sunxi_mmc_setup - Common setup function for mmc module clocks
283 *
284 * The only difference between module clocks on different platforms is the
285 * width of the mux register bits and the valid values, which are passed in
286 * through struct factors_data. The phase clocks parts are identical.
287 */
sunxi_mmc_setup(struct device_node * node,const struct factors_data * data,spinlock_t * lock)288 static void __init sunxi_mmc_setup(struct device_node *node,
289 const struct factors_data *data,
290 spinlock_t *lock)
291 {
292 struct clk_onecell_data *clk_data;
293 const char *parent;
294 void __iomem *reg;
295 int i;
296
297 reg = of_io_request_and_map(node, 0, of_node_full_name(node));
298 if (IS_ERR(reg)) {
299 pr_err("Couldn't map the %pOFn clock registers\n", node);
300 return;
301 }
302
303 clk_data = kmalloc(sizeof(*clk_data), GFP_KERNEL);
304 if (!clk_data)
305 return;
306
307 clk_data->clks = kcalloc(3, sizeof(*clk_data->clks), GFP_KERNEL);
308 if (!clk_data->clks)
309 goto err_free_data;
310
311 clk_data->clk_num = 3;
312 clk_data->clks[0] = sunxi_factors_register(node, data, lock, reg);
313 if (!clk_data->clks[0])
314 goto err_free_clks;
315
316 parent = __clk_get_name(clk_data->clks[0]);
317
318 for (i = 1; i < 3; i++) {
319 struct clk_init_data init = {
320 .num_parents = 1,
321 .parent_names = &parent,
322 .ops = &mmc_clk_ops,
323 };
324 struct mmc_phase *phase;
325
326 phase = kmalloc(sizeof(*phase), GFP_KERNEL);
327 if (!phase)
328 continue;
329
330 phase->hw.init = &init;
331 phase->reg = reg;
332 phase->lock = lock;
333
334 if (i == 1)
335 phase->offset = 8;
336 else
337 phase->offset = 20;
338
339 if (of_property_read_string_index(node, "clock-output-names",
340 i, &init.name))
341 init.name = node->name;
342
343 clk_data->clks[i] = clk_register(NULL, &phase->hw);
344 if (IS_ERR(clk_data->clks[i])) {
345 kfree(phase);
346 continue;
347 }
348 }
349
350 of_clk_add_provider(node, of_clk_src_onecell_get, clk_data);
351
352 return;
353
354 err_free_clks:
355 kfree(clk_data->clks);
356 err_free_data:
357 kfree(clk_data);
358 }
359
360 static DEFINE_SPINLOCK(sun4i_a10_mmc_lock);
361
sun4i_a10_mmc_setup(struct device_node * node)362 static void __init sun4i_a10_mmc_setup(struct device_node *node)
363 {
364 sunxi_mmc_setup(node, &sun4i_a10_mod0_data, &sun4i_a10_mmc_lock);
365 }
366 CLK_OF_DECLARE(sun4i_a10_mmc, "allwinner,sun4i-a10-mmc-clk", sun4i_a10_mmc_setup);
367
368 static DEFINE_SPINLOCK(sun9i_a80_mmc_lock);
369
sun9i_a80_mmc_setup(struct device_node * node)370 static void __init sun9i_a80_mmc_setup(struct device_node *node)
371 {
372 sunxi_mmc_setup(node, &sun9i_a80_mod0_data, &sun9i_a80_mmc_lock);
373 }
374 CLK_OF_DECLARE(sun9i_a80_mmc, "allwinner,sun9i-a80-mmc-clk", sun9i_a80_mmc_setup);
375