Merge tag 'asm-generic-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd...
[linux-block.git] / drivers / clk / clk-renesas-pcie.c
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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Driver for Renesas 9-series PCIe clock generator driver
4 *
5 * The following series can be supported:
6 * - 9FGV/9DBV/9DMV/9FGL/9DML/9QXL/9SQ
7 * Currently supported:
8 * - 9FGV0241
9 *
10 * Copyright (C) 2022 Marek Vasut <marex@denx.de>
11 */
12
13#include <linux/clk-provider.h>
14#include <linux/i2c.h>
15#include <linux/mod_devicetable.h>
16#include <linux/module.h>
17#include <linux/of.h>
18#include <linux/regmap.h>
19
20#define RS9_REG_OE 0x0
21#define RS9_REG_OE_DIF_OE(n) BIT((n) + 1)
22#define RS9_REG_SS 0x1
23#define RS9_REG_SS_AMP_0V6 0x0
24#define RS9_REG_SS_AMP_0V7 0x1
25#define RS9_REG_SS_AMP_0V8 0x2
26#define RS9_REG_SS_AMP_0V9 0x3
27#define RS9_REG_SS_AMP_MASK 0x3
28#define RS9_REG_SS_SSC_100 0
29#define RS9_REG_SS_SSC_M025 (1 << 3)
30#define RS9_REG_SS_SSC_M050 (3 << 3)
31#define RS9_REG_SS_SSC_MASK (3 << 3)
32#define RS9_REG_SS_SSC_LOCK BIT(5)
33#define RS9_REG_SR 0x2
34#define RS9_REG_SR_2V0_DIF(n) 0
35#define RS9_REG_SR_3V0_DIF(n) BIT((n) + 1)
36#define RS9_REG_SR_DIF_MASK(n) BIT((n) + 1)
37#define RS9_REG_REF 0x3
38#define RS9_REG_REF_OE BIT(4)
39#define RS9_REG_REF_OD BIT(5)
40#define RS9_REG_REF_SR_SLOWEST 0
41#define RS9_REG_REF_SR_SLOW (1 << 6)
42#define RS9_REG_REF_SR_FAST (2 << 6)
43#define RS9_REG_REF_SR_FASTER (3 << 6)
44#define RS9_REG_VID 0x5
45#define RS9_REG_DID 0x6
46#define RS9_REG_BCP 0x7
47
48/* Supported Renesas 9-series models. */
49enum rs9_model {
50 RENESAS_9FGV0241,
51};
52
53/* Structure to describe features of a particular 9-series model */
54struct rs9_chip_info {
55 const enum rs9_model model;
56 unsigned int num_clks;
57};
58
59struct rs9_driver_data {
60 struct i2c_client *client;
61 struct regmap *regmap;
62 const struct rs9_chip_info *chip_info;
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63 struct clk_hw *clk_dif[2];
64 u8 pll_amplitude;
65 u8 pll_ssc;
66 u8 clk_dif_sr;
67};
68
69/*
70 * Renesas 9-series i2c regmap
71 */
72static const struct regmap_range rs9_readable_ranges[] = {
73 regmap_reg_range(RS9_REG_OE, RS9_REG_REF),
74 regmap_reg_range(RS9_REG_VID, RS9_REG_BCP),
75};
76
77static const struct regmap_access_table rs9_readable_table = {
78 .yes_ranges = rs9_readable_ranges,
79 .n_yes_ranges = ARRAY_SIZE(rs9_readable_ranges),
80};
81
82static const struct regmap_range rs9_writeable_ranges[] = {
83 regmap_reg_range(RS9_REG_OE, RS9_REG_REF),
84 regmap_reg_range(RS9_REG_BCP, RS9_REG_BCP),
85};
86
87static const struct regmap_access_table rs9_writeable_table = {
88 .yes_ranges = rs9_writeable_ranges,
89 .n_yes_ranges = ARRAY_SIZE(rs9_writeable_ranges),
90};
91
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92static int rs9_regmap_i2c_write(void *context,
93 unsigned int reg, unsigned int val)
94{
95 struct i2c_client *i2c = context;
96 const u8 data[3] = { reg, 1, val };
97 const int count = ARRAY_SIZE(data);
98 int ret;
99
100 ret = i2c_master_send(i2c, data, count);
101 if (ret == count)
102 return 0;
103 else if (ret < 0)
104 return ret;
105 else
106 return -EIO;
107}
108
109static int rs9_regmap_i2c_read(void *context,
110 unsigned int reg, unsigned int *val)
111{
112 struct i2c_client *i2c = context;
113 struct i2c_msg xfer[2];
114 u8 txdata = reg;
115 u8 rxdata[2];
116 int ret;
117
118 xfer[0].addr = i2c->addr;
119 xfer[0].flags = 0;
120 xfer[0].len = 1;
121 xfer[0].buf = (void *)&txdata;
122
123 xfer[1].addr = i2c->addr;
124 xfer[1].flags = I2C_M_RD;
125 xfer[1].len = 2;
126 xfer[1].buf = (void *)rxdata;
127
128 ret = i2c_transfer(i2c->adapter, xfer, 2);
129 if (ret < 0)
130 return ret;
131 if (ret != 2)
132 return -EIO;
133
134 /*
135 * Byte 0 is transfer length, which is always 1 due
136 * to BCP register programming to 1 in rs9_probe(),
137 * ignore it and use data from Byte 1.
138 */
139 *val = rxdata[1];
140 return 0;
141}
142
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143static const struct regmap_config rs9_regmap_config = {
144 .reg_bits = 8,
145 .val_bits = 8,
632e0473 146 .cache_type = REGCACHE_FLAT,
2ff4ba9e 147 .max_register = RS9_REG_BCP,
632e0473 148 .num_reg_defaults_raw = 0x8,
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149 .rd_table = &rs9_readable_table,
150 .wr_table = &rs9_writeable_table,
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151 .reg_write = rs9_regmap_i2c_write,
152 .reg_read = rs9_regmap_i2c_read,
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153};
154
155static int rs9_get_output_config(struct rs9_driver_data *rs9, int idx)
156{
157 struct i2c_client *client = rs9->client;
158 unsigned char name[5] = "DIF0";
159 struct device_node *np;
160 int ret;
161 u32 sr;
162
163 /* Set defaults */
164 rs9->clk_dif_sr &= ~RS9_REG_SR_DIF_MASK(idx);
165 rs9->clk_dif_sr |= RS9_REG_SR_3V0_DIF(idx);
166
167 snprintf(name, 5, "DIF%d", idx);
168 np = of_get_child_by_name(client->dev.of_node, name);
169 if (!np)
170 return 0;
171
172 /* Output clock slew rate */
173 ret = of_property_read_u32(np, "renesas,slew-rate", &sr);
174 of_node_put(np);
175 if (!ret) {
176 if (sr == 2000000) { /* 2V/ns */
177 rs9->clk_dif_sr &= ~RS9_REG_SR_DIF_MASK(idx);
178 rs9->clk_dif_sr |= RS9_REG_SR_2V0_DIF(idx);
179 } else if (sr == 3000000) { /* 3V/ns (default) */
180 rs9->clk_dif_sr &= ~RS9_REG_SR_DIF_MASK(idx);
181 rs9->clk_dif_sr |= RS9_REG_SR_3V0_DIF(idx);
182 } else
183 ret = dev_err_probe(&client->dev, -EINVAL,
184 "Invalid renesas,slew-rate value\n");
185 }
186
187 return ret;
188}
189
190static int rs9_get_common_config(struct rs9_driver_data *rs9)
191{
192 struct i2c_client *client = rs9->client;
193 struct device_node *np = client->dev.of_node;
194 unsigned int amp, ssc;
195 int ret;
196
197 /* Set defaults */
198 rs9->pll_amplitude = RS9_REG_SS_AMP_0V7;
199 rs9->pll_ssc = RS9_REG_SS_SSC_100;
200
201 /* Output clock amplitude */
202 ret = of_property_read_u32(np, "renesas,out-amplitude-microvolt",
203 &amp);
204 if (!ret) {
205 if (amp == 600000) /* 0.6V */
206 rs9->pll_amplitude = RS9_REG_SS_AMP_0V6;
207 else if (amp == 700000) /* 0.7V (default) */
208 rs9->pll_amplitude = RS9_REG_SS_AMP_0V7;
209 else if (amp == 800000) /* 0.8V */
210 rs9->pll_amplitude = RS9_REG_SS_AMP_0V8;
211 else if (amp == 900000) /* 0.9V */
212 rs9->pll_amplitude = RS9_REG_SS_AMP_0V9;
213 else
214 return dev_err_probe(&client->dev, -EINVAL,
215 "Invalid renesas,out-amplitude-microvolt value\n");
216 }
217
218 /* Output clock spread spectrum */
219 ret = of_property_read_u32(np, "renesas,out-spread-spectrum", &ssc);
220 if (!ret) {
221 if (ssc == 100000) /* 100% ... no spread (default) */
222 rs9->pll_ssc = RS9_REG_SS_SSC_100;
223 else if (ssc == 99750) /* -0.25% ... down spread */
224 rs9->pll_ssc = RS9_REG_SS_SSC_M025;
225 else if (ssc == 99500) /* -0.50% ... down spread */
226 rs9->pll_ssc = RS9_REG_SS_SSC_M050;
227 else
228 return dev_err_probe(&client->dev, -EINVAL,
229 "Invalid renesas,out-spread-spectrum value\n");
230 }
231
232 return 0;
233}
234
235static void rs9_update_config(struct rs9_driver_data *rs9)
236{
237 int i;
238
239 /* If amplitude is non-default, update it. */
240 if (rs9->pll_amplitude != RS9_REG_SS_AMP_0V7) {
241 regmap_update_bits(rs9->regmap, RS9_REG_SS, RS9_REG_SS_AMP_MASK,
242 rs9->pll_amplitude);
243 }
244
245 /* If SSC is non-default, update it. */
246 if (rs9->pll_ssc != RS9_REG_SS_SSC_100) {
247 regmap_update_bits(rs9->regmap, RS9_REG_SS, RS9_REG_SS_SSC_MASK,
248 rs9->pll_ssc);
249 }
250
251 for (i = 0; i < rs9->chip_info->num_clks; i++) {
252 if (rs9->clk_dif_sr & RS9_REG_SR_3V0_DIF(i))
253 continue;
254
255 regmap_update_bits(rs9->regmap, RS9_REG_SR, RS9_REG_SR_3V0_DIF(i),
256 rs9->clk_dif_sr & RS9_REG_SR_3V0_DIF(i));
257 }
258}
259
260static struct clk_hw *
261rs9_of_clk_get(struct of_phandle_args *clkspec, void *data)
262{
263 struct rs9_driver_data *rs9 = data;
264 unsigned int idx = clkspec->args[0];
265
266 return rs9->clk_dif[idx];
267}
268
5baa12cf 269static int rs9_probe(struct i2c_client *client)
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270{
271 unsigned char name[5] = "DIF0";
272 struct rs9_driver_data *rs9;
273 struct clk_hw *hw;
274 int i, ret;
275
276 rs9 = devm_kzalloc(&client->dev, sizeof(*rs9), GFP_KERNEL);
277 if (!rs9)
278 return -ENOMEM;
279
280 i2c_set_clientdata(client, rs9);
281 rs9->client = client;
282 rs9->chip_info = device_get_match_data(&client->dev);
283 if (!rs9->chip_info)
284 return -EINVAL;
285
286 /* Fetch common configuration from DT (if specified) */
287 ret = rs9_get_common_config(rs9);
288 if (ret)
289 return ret;
290
291 /* Fetch DIFx output configuration from DT (if specified) */
292 for (i = 0; i < rs9->chip_info->num_clks; i++) {
293 ret = rs9_get_output_config(rs9, i);
294 if (ret)
295 return ret;
296 }
297
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298 rs9->regmap = devm_regmap_init(&client->dev, NULL,
299 client, &rs9_regmap_config);
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300 if (IS_ERR(rs9->regmap))
301 return dev_err_probe(&client->dev, PTR_ERR(rs9->regmap),
302 "Failed to allocate register map\n");
303
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304 /* Always read back 1 Byte via I2C */
305 ret = regmap_write(rs9->regmap, RS9_REG_BCP, 1);
306 if (ret < 0)
307 return ret;
308
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309 /* Register clock */
310 for (i = 0; i < rs9->chip_info->num_clks; i++) {
311 snprintf(name, 5, "DIF%d", i);
312 hw = devm_clk_hw_register_fixed_factor_index(&client->dev, name,
313 0, 0, 4, 1);
314 if (IS_ERR(hw))
315 return PTR_ERR(hw);
316
317 rs9->clk_dif[i] = hw;
318 }
319
320 ret = devm_of_clk_add_hw_provider(&client->dev, rs9_of_clk_get, rs9);
321 if (!ret)
322 rs9_update_config(rs9);
323
324 return ret;
325}
326
327static int __maybe_unused rs9_suspend(struct device *dev)
328{
329 struct rs9_driver_data *rs9 = dev_get_drvdata(dev);
330
331 regcache_cache_only(rs9->regmap, true);
332 regcache_mark_dirty(rs9->regmap);
333
334 return 0;
335}
336
337static int __maybe_unused rs9_resume(struct device *dev)
338{
339 struct rs9_driver_data *rs9 = dev_get_drvdata(dev);
340 int ret;
341
342 regcache_cache_only(rs9->regmap, false);
343 ret = regcache_sync(rs9->regmap);
344 if (ret)
345 dev_err(dev, "Failed to restore register map: %d\n", ret);
346 return ret;
347}
348
349static const struct rs9_chip_info renesas_9fgv0241_info = {
350 .model = RENESAS_9FGV0241,
351 .num_clks = 2,
352};
353
354static const struct i2c_device_id rs9_id[] = {
355 { "9fgv0241", .driver_data = RENESAS_9FGV0241 },
356 { }
357};
358MODULE_DEVICE_TABLE(i2c, rs9_id);
359
360static const struct of_device_id clk_rs9_of_match[] = {
361 { .compatible = "renesas,9fgv0241", .data = &renesas_9fgv0241_info },
362 { }
363};
364MODULE_DEVICE_TABLE(of, clk_rs9_of_match);
365
366static SIMPLE_DEV_PM_OPS(rs9_pm_ops, rs9_suspend, rs9_resume);
367
368static struct i2c_driver rs9_driver = {
369 .driver = {
370 .name = "clk-renesas-pcie-9series",
371 .pm = &rs9_pm_ops,
372 .of_match_table = clk_rs9_of_match,
373 },
5baa12cf 374 .probe_new = rs9_probe,
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375 .id_table = rs9_id,
376};
377module_i2c_driver(rs9_driver);
378
379MODULE_AUTHOR("Marek Vasut <marex@denx.de>");
380MODULE_DESCRIPTION("Renesas 9-series PCIe clock generator driver");
381MODULE_LICENSE("GPL");