xref: /openbmc/linux/drivers/clk/clk-s2mps11.c (revision 94c7b6fc)
1 /*
2  * clk-s2mps11.c - Clock driver for S2MPS11.
3  *
4  * Copyright (C) 2013,2014 Samsung Electornics
5  *
6  * This program is free software; you can redistribute  it and/or modify it
7  * under  the terms of  the GNU General  Public License as published by the
8  * Free Software Foundation;  either version 2 of the  License, or (at your
9  * option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  */
17 
18 #include <linux/module.h>
19 #include <linux/err.h>
20 #include <linux/of.h>
21 #include <linux/clkdev.h>
22 #include <linux/regmap.h>
23 #include <linux/clk-provider.h>
24 #include <linux/platform_device.h>
25 #include <linux/mfd/samsung/s2mps11.h>
26 #include <linux/mfd/samsung/s2mps14.h>
27 #include <linux/mfd/samsung/s5m8767.h>
28 #include <linux/mfd/samsung/core.h>
29 
30 #define s2mps11_name(a) (a->hw.init->name)
31 
32 static struct clk **clk_table;
33 static struct clk_onecell_data clk_data;
34 
35 enum {
36 	S2MPS11_CLK_AP = 0,
37 	S2MPS11_CLK_CP,
38 	S2MPS11_CLK_BT,
39 	S2MPS11_CLKS_NUM,
40 };
41 
42 struct s2mps11_clk {
43 	struct sec_pmic_dev *iodev;
44 	struct device_node *clk_np;
45 	struct clk_hw hw;
46 	struct clk *clk;
47 	struct clk_lookup *lookup;
48 	u32 mask;
49 	bool enabled;
50 	unsigned int reg;
51 };
52 
53 static struct s2mps11_clk *to_s2mps11_clk(struct clk_hw *hw)
54 {
55 	return container_of(hw, struct s2mps11_clk, hw);
56 }
57 
58 static int s2mps11_clk_prepare(struct clk_hw *hw)
59 {
60 	struct s2mps11_clk *s2mps11 = to_s2mps11_clk(hw);
61 	int ret;
62 
63 	ret = regmap_update_bits(s2mps11->iodev->regmap_pmic,
64 				 s2mps11->reg,
65 				 s2mps11->mask, s2mps11->mask);
66 	if (!ret)
67 		s2mps11->enabled = true;
68 
69 	return ret;
70 }
71 
72 static void s2mps11_clk_unprepare(struct clk_hw *hw)
73 {
74 	struct s2mps11_clk *s2mps11 = to_s2mps11_clk(hw);
75 	int ret;
76 
77 	ret = regmap_update_bits(s2mps11->iodev->regmap_pmic, s2mps11->reg,
78 			   s2mps11->mask, ~s2mps11->mask);
79 
80 	if (!ret)
81 		s2mps11->enabled = false;
82 }
83 
84 static int s2mps11_clk_is_enabled(struct clk_hw *hw)
85 {
86 	struct s2mps11_clk *s2mps11 = to_s2mps11_clk(hw);
87 
88 	return s2mps11->enabled;
89 }
90 
91 static unsigned long s2mps11_clk_recalc_rate(struct clk_hw *hw,
92 					     unsigned long parent_rate)
93 {
94 	struct s2mps11_clk *s2mps11 = to_s2mps11_clk(hw);
95 	if (s2mps11->enabled)
96 		return 32768;
97 	else
98 		return 0;
99 }
100 
101 static struct clk_ops s2mps11_clk_ops = {
102 	.prepare	= s2mps11_clk_prepare,
103 	.unprepare	= s2mps11_clk_unprepare,
104 	.is_enabled	= s2mps11_clk_is_enabled,
105 	.recalc_rate	= s2mps11_clk_recalc_rate,
106 };
107 
108 static struct clk_init_data s2mps11_clks_init[S2MPS11_CLKS_NUM] = {
109 	[S2MPS11_CLK_AP] = {
110 		.name = "s2mps11_ap",
111 		.ops = &s2mps11_clk_ops,
112 		.flags = CLK_IS_ROOT,
113 	},
114 	[S2MPS11_CLK_CP] = {
115 		.name = "s2mps11_cp",
116 		.ops = &s2mps11_clk_ops,
117 		.flags = CLK_IS_ROOT,
118 	},
119 	[S2MPS11_CLK_BT] = {
120 		.name = "s2mps11_bt",
121 		.ops = &s2mps11_clk_ops,
122 		.flags = CLK_IS_ROOT,
123 	},
124 };
125 
126 static struct clk_init_data s2mps14_clks_init[S2MPS11_CLKS_NUM] = {
127 	[S2MPS11_CLK_AP] = {
128 		.name = "s2mps14_ap",
129 		.ops = &s2mps11_clk_ops,
130 		.flags = CLK_IS_ROOT,
131 	},
132 	[S2MPS11_CLK_BT] = {
133 		.name = "s2mps14_bt",
134 		.ops = &s2mps11_clk_ops,
135 		.flags = CLK_IS_ROOT,
136 	},
137 };
138 
139 static struct device_node *s2mps11_clk_parse_dt(struct platform_device *pdev,
140 		struct clk_init_data *clks_init)
141 {
142 	struct sec_pmic_dev *iodev = dev_get_drvdata(pdev->dev.parent);
143 	struct device_node *clk_np;
144 	int i;
145 
146 	if (!iodev->dev->of_node)
147 		return ERR_PTR(-EINVAL);
148 
149 	clk_np = of_get_child_by_name(iodev->dev->of_node, "clocks");
150 	if (!clk_np) {
151 		dev_err(&pdev->dev, "could not find clock sub-node\n");
152 		return ERR_PTR(-EINVAL);
153 	}
154 
155 	for (i = 0; i < S2MPS11_CLKS_NUM; i++) {
156 		if (!clks_init[i].name)
157 			continue; /* Skip clocks not present in some devices */
158 		of_property_read_string_index(clk_np, "clock-output-names", i,
159 				&clks_init[i].name);
160 	}
161 
162 	return clk_np;
163 }
164 
165 static int s2mps11_clk_probe(struct platform_device *pdev)
166 {
167 	struct sec_pmic_dev *iodev = dev_get_drvdata(pdev->dev.parent);
168 	struct s2mps11_clk *s2mps11_clks, *s2mps11_clk;
169 	unsigned int s2mps11_reg;
170 	struct clk_init_data *clks_init;
171 	int i, ret = 0;
172 	u32 val;
173 
174 	s2mps11_clks = devm_kzalloc(&pdev->dev, sizeof(*s2mps11_clk) *
175 					S2MPS11_CLKS_NUM, GFP_KERNEL);
176 	if (!s2mps11_clks)
177 		return -ENOMEM;
178 
179 	s2mps11_clk = s2mps11_clks;
180 
181 	clk_table = devm_kzalloc(&pdev->dev, sizeof(struct clk *) *
182 				 S2MPS11_CLKS_NUM, GFP_KERNEL);
183 	if (!clk_table)
184 		return -ENOMEM;
185 
186 	switch(platform_get_device_id(pdev)->driver_data) {
187 	case S2MPS11X:
188 		s2mps11_reg = S2MPS11_REG_RTC_CTRL;
189 		clks_init = s2mps11_clks_init;
190 		break;
191 	case S2MPS14X:
192 		s2mps11_reg = S2MPS14_REG_RTCCTRL;
193 		clks_init = s2mps14_clks_init;
194 		break;
195 	case S5M8767X:
196 		s2mps11_reg = S5M8767_REG_CTRL1;
197 		clks_init = s2mps11_clks_init;
198 		break;
199 	default:
200 		dev_err(&pdev->dev, "Invalid device type\n");
201 		return -EINVAL;
202 	};
203 
204 	/* Store clocks of_node in first element of s2mps11_clks array */
205 	s2mps11_clks->clk_np = s2mps11_clk_parse_dt(pdev, clks_init);
206 	if (IS_ERR(s2mps11_clks->clk_np))
207 		return PTR_ERR(s2mps11_clks->clk_np);
208 
209 	for (i = 0; i < S2MPS11_CLKS_NUM; i++, s2mps11_clk++) {
210 		if (!clks_init[i].name)
211 			continue; /* Skip clocks not present in some devices */
212 		s2mps11_clk->iodev = iodev;
213 		s2mps11_clk->hw.init = &clks_init[i];
214 		s2mps11_clk->mask = 1 << i;
215 		s2mps11_clk->reg = s2mps11_reg;
216 
217 		ret = regmap_read(s2mps11_clk->iodev->regmap_pmic,
218 				  s2mps11_clk->reg, &val);
219 		if (ret < 0)
220 			goto err_reg;
221 
222 		s2mps11_clk->enabled = val & s2mps11_clk->mask;
223 
224 		s2mps11_clk->clk = devm_clk_register(&pdev->dev,
225 							&s2mps11_clk->hw);
226 		if (IS_ERR(s2mps11_clk->clk)) {
227 			dev_err(&pdev->dev, "Fail to register : %s\n",
228 						s2mps11_name(s2mps11_clk));
229 			ret = PTR_ERR(s2mps11_clk->clk);
230 			goto err_reg;
231 		}
232 
233 		s2mps11_clk->lookup = clkdev_alloc(s2mps11_clk->clk,
234 					s2mps11_name(s2mps11_clk), NULL);
235 		if (!s2mps11_clk->lookup) {
236 			ret = -ENOMEM;
237 			goto err_lup;
238 		}
239 
240 		clkdev_add(s2mps11_clk->lookup);
241 	}
242 
243 	for (i = 0; i < S2MPS11_CLKS_NUM; i++) {
244 		/* Skip clocks not present on S2MPS14 */
245 		if (!clks_init[i].name)
246 			continue;
247 		clk_table[i] = s2mps11_clks[i].clk;
248 	}
249 
250 	clk_data.clks = clk_table;
251 	clk_data.clk_num = S2MPS11_CLKS_NUM;
252 	of_clk_add_provider(s2mps11_clks->clk_np, of_clk_src_onecell_get,
253 			&clk_data);
254 
255 	platform_set_drvdata(pdev, s2mps11_clks);
256 
257 	return ret;
258 err_lup:
259 	devm_clk_unregister(&pdev->dev, s2mps11_clk->clk);
260 err_reg:
261 	while (s2mps11_clk > s2mps11_clks) {
262 		if (s2mps11_clk->lookup) {
263 			clkdev_drop(s2mps11_clk->lookup);
264 			devm_clk_unregister(&pdev->dev, s2mps11_clk->clk);
265 		}
266 		s2mps11_clk--;
267 	}
268 
269 	return ret;
270 }
271 
272 static int s2mps11_clk_remove(struct platform_device *pdev)
273 {
274 	struct s2mps11_clk *s2mps11_clks = platform_get_drvdata(pdev);
275 	int i;
276 
277 	of_clk_del_provider(s2mps11_clks[0].clk_np);
278 	/* Drop the reference obtained in s2mps11_clk_parse_dt */
279 	of_node_put(s2mps11_clks[0].clk_np);
280 
281 	for (i = 0; i < S2MPS11_CLKS_NUM; i++) {
282 		/* Skip clocks not present on S2MPS14 */
283 		if (!s2mps11_clks[i].lookup)
284 			continue;
285 		clkdev_drop(s2mps11_clks[i].lookup);
286 	}
287 
288 	return 0;
289 }
290 
291 static const struct platform_device_id s2mps11_clk_id[] = {
292 	{ "s2mps11-clk", S2MPS11X},
293 	{ "s2mps14-clk", S2MPS14X},
294 	{ "s5m8767-clk", S5M8767X},
295 	{ },
296 };
297 MODULE_DEVICE_TABLE(platform, s2mps11_clk_id);
298 
299 static struct platform_driver s2mps11_clk_driver = {
300 	.driver = {
301 		.name  = "s2mps11-clk",
302 		.owner = THIS_MODULE,
303 	},
304 	.probe = s2mps11_clk_probe,
305 	.remove = s2mps11_clk_remove,
306 	.id_table = s2mps11_clk_id,
307 };
308 
309 static int __init s2mps11_clk_init(void)
310 {
311 	return platform_driver_register(&s2mps11_clk_driver);
312 }
313 subsys_initcall(s2mps11_clk_init);
314 
315 static void __init s2mps11_clk_cleanup(void)
316 {
317 	platform_driver_unregister(&s2mps11_clk_driver);
318 }
319 module_exit(s2mps11_clk_cleanup);
320 
321 MODULE_DESCRIPTION("S2MPS11 Clock Driver");
322 MODULE_AUTHOR("Yadwinder Singh Brar <yadi.brar@samsung.com>");
323 MODULE_LICENSE("GPL");
324