1 /*
2 * Xilinx 'Clocking Wizard' driver
3 *
4 * Copyright (C) 2013 - 2014 Xilinx
5 *
6 * Sören Brinkmann <soren.brinkmann@xilinx.com>
7 *
8 * This program is free software: you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License v2 as published by
10 * the Free Software Foundation.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 */
20
21 #include <linux/platform_device.h>
22 #include <linux/clk-provider.h>
23 #include <linux/slab.h>
24 #include <linux/io.h>
25 #include <linux/of.h>
26 #include <linux/module.h>
27 #include <linux/err.h>
28
29 #define WZRD_NUM_OUTPUTS 7
30 #define WZRD_ACLK_MAX_FREQ 250000000UL
31
32 #define WZRD_CLK_CFG_REG(n) (0x200 + 4 * (n))
33
34 #define WZRD_CLkOUT0_FRAC_EN BIT(18)
35 #define WZRD_CLkFBOUT_FRAC_EN BIT(26)
36
37 #define WZRD_CLKFBOUT_MULT_SHIFT 8
38 #define WZRD_CLKFBOUT_MULT_MASK (0xff << WZRD_CLKFBOUT_MULT_SHIFT)
39 #define WZRD_DIVCLK_DIVIDE_SHIFT 0
40 #define WZRD_DIVCLK_DIVIDE_MASK (0xff << WZRD_DIVCLK_DIVIDE_SHIFT)
41 #define WZRD_CLKOUT_DIVIDE_SHIFT 0
42 #define WZRD_CLKOUT_DIVIDE_MASK (0xff << WZRD_DIVCLK_DIVIDE_SHIFT)
43
44 enum clk_wzrd_int_clks {
45 wzrd_clk_mul,
46 wzrd_clk_mul_div,
47 wzrd_clk_int_max
48 };
49
50 /**
51 * struct clk_wzrd:
52 * @clk_data: Clock data
53 * @nb: Notifier block
54 * @base: Memory base
55 * @clk_in1: Handle to input clock 'clk_in1'
56 * @axi_clk: Handle to input clock 's_axi_aclk'
57 * @clks_internal: Internal clocks
58 * @clkout: Output clocks
59 * @speed_grade: Speed grade of the device
60 * @suspended: Flag indicating power state of the device
61 */
62 struct clk_wzrd {
63 struct clk_onecell_data clk_data;
64 struct notifier_block nb;
65 void __iomem *base;
66 struct clk *clk_in1;
67 struct clk *axi_clk;
68 struct clk *clks_internal[wzrd_clk_int_max];
69 struct clk *clkout[WZRD_NUM_OUTPUTS];
70 int speed_grade;
71 bool suspended;
72 };
73 #define to_clk_wzrd(_nb) container_of(_nb, struct clk_wzrd, nb)
74
75 /* maximum frequencies for input/output clocks per speed grade */
76 static const unsigned long clk_wzrd_max_freq[] = {
77 800000000UL,
78 933000000UL,
79 1066000000UL
80 };
81
clk_wzrd_clk_notifier(struct notifier_block * nb,unsigned long event,void * data)82 static int clk_wzrd_clk_notifier(struct notifier_block *nb, unsigned long event,
83 void *data)
84 {
85 unsigned long max;
86 struct clk_notifier_data *ndata = data;
87 struct clk_wzrd *clk_wzrd = to_clk_wzrd(nb);
88
89 if (clk_wzrd->suspended)
90 return NOTIFY_OK;
91
92 if (ndata->clk == clk_wzrd->clk_in1)
93 max = clk_wzrd_max_freq[clk_wzrd->speed_grade - 1];
94 else if (ndata->clk == clk_wzrd->axi_clk)
95 max = WZRD_ACLK_MAX_FREQ;
96 else
97 return NOTIFY_DONE; /* should never happen */
98
99 switch (event) {
100 case PRE_RATE_CHANGE:
101 if (ndata->new_rate > max)
102 return NOTIFY_BAD;
103 return NOTIFY_OK;
104 case POST_RATE_CHANGE:
105 case ABORT_RATE_CHANGE:
106 default:
107 return NOTIFY_DONE;
108 }
109 }
110
clk_wzrd_suspend(struct device * dev)111 static int __maybe_unused clk_wzrd_suspend(struct device *dev)
112 {
113 struct clk_wzrd *clk_wzrd = dev_get_drvdata(dev);
114
115 clk_disable_unprepare(clk_wzrd->axi_clk);
116 clk_wzrd->suspended = true;
117
118 return 0;
119 }
120
clk_wzrd_resume(struct device * dev)121 static int __maybe_unused clk_wzrd_resume(struct device *dev)
122 {
123 int ret;
124 struct clk_wzrd *clk_wzrd = dev_get_drvdata(dev);
125
126 ret = clk_prepare_enable(clk_wzrd->axi_clk);
127 if (ret) {
128 dev_err(dev, "unable to enable s_axi_aclk\n");
129 return ret;
130 }
131
132 clk_wzrd->suspended = false;
133
134 return 0;
135 }
136
137 static SIMPLE_DEV_PM_OPS(clk_wzrd_dev_pm_ops, clk_wzrd_suspend,
138 clk_wzrd_resume);
139
clk_wzrd_probe(struct platform_device * pdev)140 static int clk_wzrd_probe(struct platform_device *pdev)
141 {
142 int i, ret;
143 u32 reg;
144 unsigned long rate;
145 const char *clk_name;
146 struct clk_wzrd *clk_wzrd;
147 struct resource *mem;
148 struct device_node *np = pdev->dev.of_node;
149
150 clk_wzrd = devm_kzalloc(&pdev->dev, sizeof(*clk_wzrd), GFP_KERNEL);
151 if (!clk_wzrd)
152 return -ENOMEM;
153 platform_set_drvdata(pdev, clk_wzrd);
154
155 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
156 clk_wzrd->base = devm_ioremap_resource(&pdev->dev, mem);
157 if (IS_ERR(clk_wzrd->base))
158 return PTR_ERR(clk_wzrd->base);
159
160 ret = of_property_read_u32(np, "speed-grade", &clk_wzrd->speed_grade);
161 if (!ret) {
162 if (clk_wzrd->speed_grade < 1 || clk_wzrd->speed_grade > 3) {
163 dev_warn(&pdev->dev, "invalid speed grade '%d'\n",
164 clk_wzrd->speed_grade);
165 clk_wzrd->speed_grade = 0;
166 }
167 }
168
169 clk_wzrd->clk_in1 = devm_clk_get(&pdev->dev, "clk_in1");
170 if (IS_ERR(clk_wzrd->clk_in1)) {
171 if (clk_wzrd->clk_in1 != ERR_PTR(-EPROBE_DEFER))
172 dev_err(&pdev->dev, "clk_in1 not found\n");
173 return PTR_ERR(clk_wzrd->clk_in1);
174 }
175
176 clk_wzrd->axi_clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
177 if (IS_ERR(clk_wzrd->axi_clk)) {
178 if (clk_wzrd->axi_clk != ERR_PTR(-EPROBE_DEFER))
179 dev_err(&pdev->dev, "s_axi_aclk not found\n");
180 return PTR_ERR(clk_wzrd->axi_clk);
181 }
182 ret = clk_prepare_enable(clk_wzrd->axi_clk);
183 if (ret) {
184 dev_err(&pdev->dev, "enabling s_axi_aclk failed\n");
185 return ret;
186 }
187 rate = clk_get_rate(clk_wzrd->axi_clk);
188 if (rate > WZRD_ACLK_MAX_FREQ) {
189 dev_err(&pdev->dev, "s_axi_aclk frequency (%lu) too high\n",
190 rate);
191 ret = -EINVAL;
192 goto err_disable_clk;
193 }
194
195 /* we don't support fractional div/mul yet */
196 reg = readl(clk_wzrd->base + WZRD_CLK_CFG_REG(0)) &
197 WZRD_CLkFBOUT_FRAC_EN;
198 reg |= readl(clk_wzrd->base + WZRD_CLK_CFG_REG(2)) &
199 WZRD_CLkOUT0_FRAC_EN;
200 if (reg)
201 dev_warn(&pdev->dev, "fractional div/mul not supported\n");
202
203 /* register multiplier */
204 reg = (readl(clk_wzrd->base + WZRD_CLK_CFG_REG(0)) &
205 WZRD_CLKFBOUT_MULT_MASK) >> WZRD_CLKFBOUT_MULT_SHIFT;
206 clk_name = kasprintf(GFP_KERNEL, "%s_mul", dev_name(&pdev->dev));
207 if (!clk_name) {
208 ret = -ENOMEM;
209 goto err_disable_clk;
210 }
211 clk_wzrd->clks_internal[wzrd_clk_mul] = clk_register_fixed_factor(
212 &pdev->dev, clk_name,
213 __clk_get_name(clk_wzrd->clk_in1),
214 0, reg, 1);
215 kfree(clk_name);
216 if (IS_ERR(clk_wzrd->clks_internal[wzrd_clk_mul])) {
217 dev_err(&pdev->dev, "unable to register fixed-factor clock\n");
218 ret = PTR_ERR(clk_wzrd->clks_internal[wzrd_clk_mul]);
219 goto err_disable_clk;
220 }
221
222 /* register div */
223 reg = (readl(clk_wzrd->base + WZRD_CLK_CFG_REG(0)) &
224 WZRD_DIVCLK_DIVIDE_MASK) >> WZRD_DIVCLK_DIVIDE_SHIFT;
225 clk_name = kasprintf(GFP_KERNEL, "%s_mul_div", dev_name(&pdev->dev));
226 if (!clk_name) {
227 ret = -ENOMEM;
228 goto err_rm_int_clk;
229 }
230
231 clk_wzrd->clks_internal[wzrd_clk_mul_div] = clk_register_fixed_factor(
232 &pdev->dev, clk_name,
233 __clk_get_name(clk_wzrd->clks_internal[wzrd_clk_mul]),
234 0, 1, reg);
235 if (IS_ERR(clk_wzrd->clks_internal[wzrd_clk_mul_div])) {
236 dev_err(&pdev->dev, "unable to register divider clock\n");
237 ret = PTR_ERR(clk_wzrd->clks_internal[wzrd_clk_mul_div]);
238 goto err_rm_int_clk;
239 }
240
241 /* register div per output */
242 for (i = WZRD_NUM_OUTPUTS - 1; i >= 0 ; i--) {
243 const char *clkout_name;
244
245 if (of_property_read_string_index(np, "clock-output-names", i,
246 &clkout_name)) {
247 dev_err(&pdev->dev,
248 "clock output name not specified\n");
249 ret = -EINVAL;
250 goto err_rm_int_clks;
251 }
252 reg = readl(clk_wzrd->base + WZRD_CLK_CFG_REG(2) + i * 12);
253 reg &= WZRD_CLKOUT_DIVIDE_MASK;
254 reg >>= WZRD_CLKOUT_DIVIDE_SHIFT;
255 clk_wzrd->clkout[i] = clk_register_fixed_factor(&pdev->dev,
256 clkout_name, clk_name, 0, 1, reg);
257 if (IS_ERR(clk_wzrd->clkout[i])) {
258 int j;
259
260 for (j = i + 1; j < WZRD_NUM_OUTPUTS; j++)
261 clk_unregister(clk_wzrd->clkout[j]);
262 dev_err(&pdev->dev,
263 "unable to register divider clock\n");
264 ret = PTR_ERR(clk_wzrd->clkout[i]);
265 goto err_rm_int_clks;
266 }
267 }
268
269 kfree(clk_name);
270
271 clk_wzrd->clk_data.clks = clk_wzrd->clkout;
272 clk_wzrd->clk_data.clk_num = ARRAY_SIZE(clk_wzrd->clkout);
273 of_clk_add_provider(np, of_clk_src_onecell_get, &clk_wzrd->clk_data);
274
275 if (clk_wzrd->speed_grade) {
276 clk_wzrd->nb.notifier_call = clk_wzrd_clk_notifier;
277
278 ret = clk_notifier_register(clk_wzrd->clk_in1,
279 &clk_wzrd->nb);
280 if (ret)
281 dev_warn(&pdev->dev,
282 "unable to register clock notifier\n");
283
284 ret = clk_notifier_register(clk_wzrd->axi_clk, &clk_wzrd->nb);
285 if (ret)
286 dev_warn(&pdev->dev,
287 "unable to register clock notifier\n");
288 }
289
290 return 0;
291
292 err_rm_int_clks:
293 clk_unregister(clk_wzrd->clks_internal[1]);
294 err_rm_int_clk:
295 kfree(clk_name);
296 clk_unregister(clk_wzrd->clks_internal[0]);
297 err_disable_clk:
298 clk_disable_unprepare(clk_wzrd->axi_clk);
299
300 return ret;
301 }
302
clk_wzrd_remove(struct platform_device * pdev)303 static int clk_wzrd_remove(struct platform_device *pdev)
304 {
305 int i;
306 struct clk_wzrd *clk_wzrd = platform_get_drvdata(pdev);
307
308 of_clk_del_provider(pdev->dev.of_node);
309
310 for (i = 0; i < WZRD_NUM_OUTPUTS; i++)
311 clk_unregister(clk_wzrd->clkout[i]);
312 for (i = 0; i < wzrd_clk_int_max; i++)
313 clk_unregister(clk_wzrd->clks_internal[i]);
314
315 if (clk_wzrd->speed_grade) {
316 clk_notifier_unregister(clk_wzrd->axi_clk, &clk_wzrd->nb);
317 clk_notifier_unregister(clk_wzrd->clk_in1, &clk_wzrd->nb);
318 }
319
320 clk_disable_unprepare(clk_wzrd->axi_clk);
321
322 return 0;
323 }
324
325 static const struct of_device_id clk_wzrd_ids[] = {
326 { .compatible = "xlnx,clocking-wizard" },
327 { },
328 };
329 MODULE_DEVICE_TABLE(of, clk_wzrd_ids);
330
331 static struct platform_driver clk_wzrd_driver = {
332 .driver = {
333 .name = "clk-wizard",
334 .of_match_table = clk_wzrd_ids,
335 .pm = &clk_wzrd_dev_pm_ops,
336 },
337 .probe = clk_wzrd_probe,
338 .remove = clk_wzrd_remove,
339 };
340 module_platform_driver(clk_wzrd_driver);
341
342 MODULE_LICENSE("GPL");
343 MODULE_AUTHOR("Soeren Brinkmann <soren.brinkmann@xilinx.com");
344 MODULE_DESCRIPTION("Driver for the Xilinx Clocking Wizard IP core");
345