2 * CS2000 -- CIRRUS LOGIC Fractional-N Clock Synthesizer & Clock Multiplier
4 * Copyright (C) 2015 Renesas Electronics Corporation
5 * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 #include <linux/clk-provider.h>
12 #include <linux/delay.h>
13 #include <linux/clk.h>
14 #include <linux/i2c.h>
15 #include <linux/of_device.h>
16 #include <linux/module.h>
19 #define RATIO_REG_SIZE 4
22 #define DEVICE_CTRL 0x2
23 #define DEVICE_CFG1 0x3
24 #define DEVICE_CFG2 0x4
25 #define GLOBAL_CFG 0x5
26 #define Ratio_Add(x, nth) (6 + (x * 4) + (nth))
27 #define Ratio_Val(x, nth) ((x >> (24 - (8 * nth))) & 0xFF)
28 #define Val_Ratio(x, nth) ((x & 0xFF) << (24 - (8 * nth)))
29 #define FUNC_CFG1 0x16
30 #define FUNC_CFG2 0x17
33 #define REVISION_MASK (0x7)
34 #define REVISION_B2_B3 (0x4)
35 #define REVISION_C1 (0x6)
38 #define PLL_UNLOCK (1 << 7)
41 #define RSEL(x) (((x) & 0x3) << 3)
42 #define RSEL_MASK RSEL(0x3)
48 #define CH_SIZE_ERR(ch) ((ch < 0) || (ch >= CH_MAX))
49 #define hw_to_priv(_hw) container_of(_hw, struct cs2000_priv, hw)
50 #define priv_to_client(priv) (priv->client)
51 #define priv_to_dev(priv) (&(priv_to_client(priv)->dev))
59 struct i2c_client *client;
64 unsigned long saved_rate;
65 unsigned long saved_parent_rate;
68 static const struct of_device_id cs2000_of_match[] = {
69 { .compatible = "cirrus,cs2000-cp", },
72 MODULE_DEVICE_TABLE(of, cs2000_of_match);
74 static const struct i2c_device_id cs2000_id[] = {
78 MODULE_DEVICE_TABLE(i2c, cs2000_id);
80 #define cs2000_read(priv, addr) \
81 i2c_smbus_read_byte_data(priv_to_client(priv), addr)
82 #define cs2000_write(priv, addr, val) \
83 i2c_smbus_write_byte_data(priv_to_client(priv), addr, val)
85 static int cs2000_bset(struct cs2000_priv *priv, u8 addr, u8 mask, u8 val)
89 data = cs2000_read(priv, addr);
96 return cs2000_write(priv, addr, data);
99 static int cs2000_enable_dev_config(struct cs2000_priv *priv, bool enable)
103 ret = cs2000_bset(priv, DEVICE_CFG1, ENDEV1,
104 enable ? ENDEV1 : 0);
108 ret = cs2000_bset(priv, GLOBAL_CFG, ENDEV2,
109 enable ? ENDEV2 : 0);
116 static int cs2000_clk_in_bound_rate(struct cs2000_priv *priv,
121 if (rate_in >= 32000000 && rate_in < 56000000)
123 else if (rate_in >= 16000000 && rate_in < 28000000)
125 else if (rate_in >= 8000000 && rate_in < 14000000)
130 return cs2000_bset(priv, FUNC_CFG1, 0x3 << 3, val << 3);
133 static int cs2000_wait_pll_lock(struct cs2000_priv *priv)
135 struct device *dev = priv_to_dev(priv);
139 for (i = 0; i < 256; i++) {
140 val = cs2000_read(priv, DEVICE_CTRL);
143 if (!(val & PLL_UNLOCK))
148 dev_err(dev, "pll lock failed\n");
153 static int cs2000_clk_out_enable(struct cs2000_priv *priv, bool enable)
155 /* enable both AUX_OUT, CLK_OUT */
156 return cs2000_write(priv, DEVICE_CTRL, enable ? 0 : 0x3);
159 static u32 cs2000_rate_to_ratio(u32 rate_in, u32 rate_out)
164 * ratio = rate_out / rate_in * 2^20
166 * To avoid over flow, rate_out is u64.
167 * The result should be u32.
169 ratio = (u64)rate_out << 20;
170 do_div(ratio, rate_in);
175 static unsigned long cs2000_ratio_to_rate(u32 ratio, u32 rate_in)
180 * ratio = rate_out / rate_in * 2^20
182 * To avoid over flow, rate_out is u64.
183 * The result should be u32 or unsigned long.
186 rate_out = (u64)ratio * rate_in;
187 return rate_out >> 20;
190 static int cs2000_ratio_set(struct cs2000_priv *priv,
191 int ch, u32 rate_in, u32 rate_out)
200 val = cs2000_rate_to_ratio(rate_in, rate_out);
201 for (i = 0; i < RATIO_REG_SIZE; i++) {
202 ret = cs2000_write(priv,
212 static u32 cs2000_ratio_get(struct cs2000_priv *priv, int ch)
219 for (i = 0; i < RATIO_REG_SIZE; i++) {
220 tmp = cs2000_read(priv, Ratio_Add(ch, i));
224 val |= Val_Ratio(tmp, i);
230 static int cs2000_ratio_select(struct cs2000_priv *priv, int ch)
240 * this driver supports static ratio mode only at this point.
242 ret = cs2000_bset(priv, DEVICE_CFG1, RSEL_MASK, RSEL(ch));
246 ret = cs2000_write(priv, DEVICE_CFG2, 0x0);
253 static unsigned long cs2000_recalc_rate(struct clk_hw *hw,
254 unsigned long parent_rate)
256 struct cs2000_priv *priv = hw_to_priv(hw);
257 int ch = 0; /* it uses ch0 only at this point */
260 ratio = cs2000_ratio_get(priv, ch);
262 return cs2000_ratio_to_rate(ratio, parent_rate);
265 static long cs2000_round_rate(struct clk_hw *hw, unsigned long rate,
266 unsigned long *parent_rate)
270 ratio = cs2000_rate_to_ratio(*parent_rate, rate);
272 return cs2000_ratio_to_rate(ratio, *parent_rate);
275 static int __cs2000_set_rate(struct cs2000_priv *priv, int ch,
276 unsigned long rate, unsigned long parent_rate)
281 ret = cs2000_clk_in_bound_rate(priv, parent_rate);
285 ret = cs2000_ratio_set(priv, ch, parent_rate, rate);
289 ret = cs2000_ratio_select(priv, ch);
293 priv->saved_rate = rate;
294 priv->saved_parent_rate = parent_rate;
299 static int cs2000_set_rate(struct clk_hw *hw,
300 unsigned long rate, unsigned long parent_rate)
302 struct cs2000_priv *priv = hw_to_priv(hw);
303 int ch = 0; /* it uses ch0 only at this point */
305 return __cs2000_set_rate(priv, ch, rate, parent_rate);
308 static int cs2000_enable(struct clk_hw *hw)
310 struct cs2000_priv *priv = hw_to_priv(hw);
313 ret = cs2000_enable_dev_config(priv, true);
317 ret = cs2000_clk_out_enable(priv, true);
321 ret = cs2000_wait_pll_lock(priv);
328 static void cs2000_disable(struct clk_hw *hw)
330 struct cs2000_priv *priv = hw_to_priv(hw);
332 cs2000_enable_dev_config(priv, false);
334 cs2000_clk_out_enable(priv, false);
337 static u8 cs2000_get_parent(struct clk_hw *hw)
339 /* always return REF_CLK */
343 static const struct clk_ops cs2000_ops = {
344 .get_parent = cs2000_get_parent,
345 .recalc_rate = cs2000_recalc_rate,
346 .round_rate = cs2000_round_rate,
347 .set_rate = cs2000_set_rate,
348 .prepare = cs2000_enable,
349 .unprepare = cs2000_disable,
352 static int cs2000_clk_get(struct cs2000_priv *priv)
354 struct i2c_client *client = priv_to_client(priv);
355 struct device *dev = &client->dev;
356 struct clk *clk_in, *ref_clk;
358 clk_in = devm_clk_get(dev, "clk_in");
359 /* not yet provided */
361 return -EPROBE_DEFER;
363 ref_clk = devm_clk_get(dev, "ref_clk");
364 /* not yet provided */
366 return -EPROBE_DEFER;
368 priv->clk_in = clk_in;
369 priv->ref_clk = ref_clk;
374 static int cs2000_clk_register(struct cs2000_priv *priv)
376 struct device *dev = priv_to_dev(priv);
377 struct device_node *np = dev->of_node;
378 struct clk_init_data init;
379 const char *name = np->name;
380 static const char *parent_names[CLK_MAX];
381 int ch = 0; /* it uses ch0 only at this point */
385 of_property_read_string(np, "clock-output-names", &name);
388 * set default rate as 1/1.
389 * otherwise .set_rate which setup ratio
390 * is never called if user requests 1/1 rate
392 rate = clk_get_rate(priv->ref_clk);
393 ret = __cs2000_set_rate(priv, ch, rate, rate);
397 parent_names[CLK_IN] = __clk_get_name(priv->clk_in);
398 parent_names[REF_CLK] = __clk_get_name(priv->ref_clk);
401 init.ops = &cs2000_ops;
402 init.flags = CLK_SET_RATE_GATE;
403 init.parent_names = parent_names;
404 init.num_parents = ARRAY_SIZE(parent_names);
406 priv->hw.init = &init;
408 ret = clk_hw_register(dev, &priv->hw);
412 ret = of_clk_add_hw_provider(np, of_clk_hw_simple_get, &priv->hw);
414 clk_hw_unregister(&priv->hw);
421 static int cs2000_version_print(struct cs2000_priv *priv)
423 struct i2c_client *client = priv_to_client(priv);
424 struct device *dev = &client->dev;
426 const char *revision;
428 val = cs2000_read(priv, DEVICE_ID);
432 /* CS2000 should be 0x0 */
436 switch (val & REVISION_MASK) {
438 revision = "B2 / B3";
447 dev_info(dev, "revision - %s\n", revision);
452 static int cs2000_remove(struct i2c_client *client)
454 struct cs2000_priv *priv = i2c_get_clientdata(client);
455 struct device *dev = &client->dev;
456 struct device_node *np = dev->of_node;
458 of_clk_del_provider(np);
460 clk_hw_unregister(&priv->hw);
465 static int cs2000_probe(struct i2c_client *client,
466 const struct i2c_device_id *id)
468 struct cs2000_priv *priv;
469 struct device *dev = &client->dev;
472 priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
476 priv->client = client;
477 i2c_set_clientdata(client, priv);
479 ret = cs2000_clk_get(priv);
483 ret = cs2000_clk_register(priv);
487 ret = cs2000_version_print(priv);
494 cs2000_remove(client);
499 static int cs2000_resume(struct device *dev)
501 struct cs2000_priv *priv = dev_get_drvdata(dev);
502 int ch = 0; /* it uses ch0 only at this point */
504 return __cs2000_set_rate(priv, ch,
506 priv->saved_parent_rate);
509 static const struct dev_pm_ops cs2000_pm_ops = {
510 .resume_early = cs2000_resume,
513 static struct i2c_driver cs2000_driver = {
516 .pm = &cs2000_pm_ops,
517 .of_match_table = cs2000_of_match,
519 .probe = cs2000_probe,
520 .remove = cs2000_remove,
521 .id_table = cs2000_id,
524 module_i2c_driver(cs2000_driver);
526 MODULE_DESCRIPTION("CS2000-CP driver");
527 MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");
528 MODULE_LICENSE("GPL v2");