1 /*
2 * clk-max77686.c - Clock driver for Maxim 77686/MAX77802
3 *
4 * Copyright (C) 2012 Samsung Electornics
5 * Jonghwa Lee <jonghwa3.lee@samsung.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms of the GNU General Public License as published by the
9 * Free Software Foundation; either version 2 of the License, or (at your
10 * option) any later version.
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, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 *
21 */
22
23 #include <linux/kernel.h>
24 #include <linux/slab.h>
25 #include <linux/err.h>
26 #include <linux/module.h>
27 #include <linux/platform_device.h>
28 #include <linux/mfd/max77620.h>
29 #include <linux/mfd/max77686.h>
30 #include <linux/mfd/max77686-private.h>
31 #include <linux/clk-provider.h>
32 #include <linux/mutex.h>
33 #include <linux/clkdev.h>
34 #include <linux/of.h>
35 #include <linux/regmap.h>
36
37 #include <dt-bindings/clock/maxim,max77686.h>
38 #include <dt-bindings/clock/maxim,max77802.h>
39 #include <dt-bindings/clock/maxim,max77620.h>
40
41 #define MAX77802_CLOCK_LOW_JITTER_SHIFT 0x3
42
43 enum max77686_chip_name {
44 CHIP_MAX77686,
45 CHIP_MAX77802,
46 CHIP_MAX77620,
47 };
48
49 struct max77686_hw_clk_info {
50 const char *name;
51 u32 clk_reg;
52 u32 clk_enable_mask;
53 u32 flags;
54 };
55
56 struct max77686_clk_init_data {
57 struct regmap *regmap;
58 struct clk_hw hw;
59 struct clk_init_data clk_idata;
60 const struct max77686_hw_clk_info *clk_info;
61 };
62
63 struct max77686_clk_driver_data {
64 enum max77686_chip_name chip;
65 struct max77686_clk_init_data *max_clk_data;
66 size_t num_clks;
67 };
68
69 static const struct
70 max77686_hw_clk_info max77686_hw_clks_info[MAX77686_CLKS_NUM] = {
71 [MAX77686_CLK_AP] = {
72 .name = "32khz_ap",
73 .clk_reg = MAX77686_REG_32KHZ,
74 .clk_enable_mask = BIT(MAX77686_CLK_AP),
75 },
76 [MAX77686_CLK_CP] = {
77 .name = "32khz_cp",
78 .clk_reg = MAX77686_REG_32KHZ,
79 .clk_enable_mask = BIT(MAX77686_CLK_CP),
80 },
81 [MAX77686_CLK_PMIC] = {
82 .name = "32khz_pmic",
83 .clk_reg = MAX77686_REG_32KHZ,
84 .clk_enable_mask = BIT(MAX77686_CLK_PMIC),
85 },
86 };
87
88 static const struct
89 max77686_hw_clk_info max77802_hw_clks_info[MAX77802_CLKS_NUM] = {
90 [MAX77802_CLK_32K_AP] = {
91 .name = "32khz_ap",
92 .clk_reg = MAX77802_REG_32KHZ,
93 .clk_enable_mask = BIT(MAX77802_CLK_32K_AP),
94 },
95 [MAX77802_CLK_32K_CP] = {
96 .name = "32khz_cp",
97 .clk_reg = MAX77802_REG_32KHZ,
98 .clk_enable_mask = BIT(MAX77802_CLK_32K_CP),
99 },
100 };
101
102 static const struct
103 max77686_hw_clk_info max77620_hw_clks_info[MAX77620_CLKS_NUM] = {
104 [MAX77620_CLK_32K_OUT0] = {
105 .name = "32khz_out0",
106 .clk_reg = MAX77620_REG_CNFG1_32K,
107 .clk_enable_mask = MAX77620_CNFG1_32K_OUT0_EN,
108 },
109 };
110
to_max77686_clk_init_data(struct clk_hw * hw)111 static struct max77686_clk_init_data *to_max77686_clk_init_data(
112 struct clk_hw *hw)
113 {
114 return container_of(hw, struct max77686_clk_init_data, hw);
115 }
116
max77686_clk_prepare(struct clk_hw * hw)117 static int max77686_clk_prepare(struct clk_hw *hw)
118 {
119 struct max77686_clk_init_data *max77686 = to_max77686_clk_init_data(hw);
120
121 return regmap_update_bits(max77686->regmap, max77686->clk_info->clk_reg,
122 max77686->clk_info->clk_enable_mask,
123 max77686->clk_info->clk_enable_mask);
124 }
125
max77686_clk_unprepare(struct clk_hw * hw)126 static void max77686_clk_unprepare(struct clk_hw *hw)
127 {
128 struct max77686_clk_init_data *max77686 = to_max77686_clk_init_data(hw);
129
130 regmap_update_bits(max77686->regmap, max77686->clk_info->clk_reg,
131 max77686->clk_info->clk_enable_mask,
132 ~max77686->clk_info->clk_enable_mask);
133 }
134
max77686_clk_is_prepared(struct clk_hw * hw)135 static int max77686_clk_is_prepared(struct clk_hw *hw)
136 {
137 struct max77686_clk_init_data *max77686 = to_max77686_clk_init_data(hw);
138 int ret;
139 u32 val;
140
141 ret = regmap_read(max77686->regmap, max77686->clk_info->clk_reg, &val);
142
143 if (ret < 0)
144 return -EINVAL;
145
146 return val & max77686->clk_info->clk_enable_mask;
147 }
148
max77686_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)149 static unsigned long max77686_recalc_rate(struct clk_hw *hw,
150 unsigned long parent_rate)
151 {
152 return 32768;
153 }
154
155 static struct clk_ops max77686_clk_ops = {
156 .prepare = max77686_clk_prepare,
157 .unprepare = max77686_clk_unprepare,
158 .is_prepared = max77686_clk_is_prepared,
159 .recalc_rate = max77686_recalc_rate,
160 };
161
162 static struct clk_hw *
of_clk_max77686_get(struct of_phandle_args * clkspec,void * data)163 of_clk_max77686_get(struct of_phandle_args *clkspec, void *data)
164 {
165 struct max77686_clk_driver_data *drv_data = data;
166 unsigned int idx = clkspec->args[0];
167
168 if (idx >= drv_data->num_clks) {
169 pr_err("%s: invalid index %u\n", __func__, idx);
170 return ERR_PTR(-EINVAL);
171 }
172
173 return &drv_data->max_clk_data[idx].hw;
174 }
175
max77686_clk_probe(struct platform_device * pdev)176 static int max77686_clk_probe(struct platform_device *pdev)
177 {
178 struct device *dev = &pdev->dev;
179 struct device *parent = dev->parent;
180 const struct platform_device_id *id = platform_get_device_id(pdev);
181 struct max77686_clk_driver_data *drv_data;
182 const struct max77686_hw_clk_info *hw_clks;
183 struct regmap *regmap;
184 int i, ret, num_clks;
185
186 drv_data = devm_kzalloc(dev, sizeof(*drv_data), GFP_KERNEL);
187 if (!drv_data)
188 return -ENOMEM;
189
190 regmap = dev_get_regmap(parent, NULL);
191 if (!regmap) {
192 dev_err(dev, "Failed to get rtc regmap\n");
193 return -ENODEV;
194 }
195
196 drv_data->chip = id->driver_data;
197
198 switch (drv_data->chip) {
199 case CHIP_MAX77686:
200 num_clks = MAX77686_CLKS_NUM;
201 hw_clks = max77686_hw_clks_info;
202 break;
203
204 case CHIP_MAX77802:
205 num_clks = MAX77802_CLKS_NUM;
206 hw_clks = max77802_hw_clks_info;
207 break;
208
209 case CHIP_MAX77620:
210 num_clks = MAX77620_CLKS_NUM;
211 hw_clks = max77620_hw_clks_info;
212 break;
213
214 default:
215 dev_err(dev, "Unknown Chip ID\n");
216 return -EINVAL;
217 }
218
219 drv_data->num_clks = num_clks;
220 drv_data->max_clk_data = devm_kcalloc(dev, num_clks,
221 sizeof(*drv_data->max_clk_data),
222 GFP_KERNEL);
223 if (!drv_data->max_clk_data)
224 return -ENOMEM;
225
226 for (i = 0; i < num_clks; i++) {
227 struct max77686_clk_init_data *max_clk_data;
228 const char *clk_name;
229
230 max_clk_data = &drv_data->max_clk_data[i];
231
232 max_clk_data->regmap = regmap;
233 max_clk_data->clk_info = &hw_clks[i];
234 max_clk_data->clk_idata.flags = hw_clks[i].flags;
235 max_clk_data->clk_idata.ops = &max77686_clk_ops;
236
237 if (parent->of_node &&
238 !of_property_read_string_index(parent->of_node,
239 "clock-output-names",
240 i, &clk_name))
241 max_clk_data->clk_idata.name = clk_name;
242 else
243 max_clk_data->clk_idata.name = hw_clks[i].name;
244
245 max_clk_data->hw.init = &max_clk_data->clk_idata;
246
247 ret = devm_clk_hw_register(dev, &max_clk_data->hw);
248 if (ret) {
249 dev_err(dev, "Failed to clock register: %d\n", ret);
250 return ret;
251 }
252
253 ret = clk_hw_register_clkdev(&max_clk_data->hw,
254 max_clk_data->clk_idata.name, NULL);
255 if (ret < 0) {
256 dev_err(dev, "Failed to clkdev register: %d\n", ret);
257 return ret;
258 }
259 }
260
261 if (parent->of_node) {
262 ret = of_clk_add_hw_provider(parent->of_node, of_clk_max77686_get,
263 drv_data);
264
265 if (ret < 0) {
266 dev_err(dev, "Failed to register OF clock provider: %d\n",
267 ret);
268 return ret;
269 }
270 }
271
272 /* MAX77802: Enable low-jitter mode on the 32khz clocks. */
273 if (drv_data->chip == CHIP_MAX77802) {
274 ret = regmap_update_bits(regmap, MAX77802_REG_32KHZ,
275 1 << MAX77802_CLOCK_LOW_JITTER_SHIFT,
276 1 << MAX77802_CLOCK_LOW_JITTER_SHIFT);
277 if (ret < 0) {
278 dev_err(dev, "Failed to config low-jitter: %d\n", ret);
279 goto remove_of_clk_provider;
280 }
281 }
282
283 return 0;
284
285 remove_of_clk_provider:
286 if (parent->of_node)
287 of_clk_del_provider(parent->of_node);
288
289 return ret;
290 }
291
max77686_clk_remove(struct platform_device * pdev)292 static int max77686_clk_remove(struct platform_device *pdev)
293 {
294 struct device *parent = pdev->dev.parent;
295
296 if (parent->of_node)
297 of_clk_del_provider(parent->of_node);
298
299 return 0;
300 }
301
302 static const struct platform_device_id max77686_clk_id[] = {
303 { "max77686-clk", .driver_data = CHIP_MAX77686, },
304 { "max77802-clk", .driver_data = CHIP_MAX77802, },
305 { "max77620-clock", .driver_data = CHIP_MAX77620, },
306 {},
307 };
308 MODULE_DEVICE_TABLE(platform, max77686_clk_id);
309
310 static struct platform_driver max77686_clk_driver = {
311 .driver = {
312 .name = "max77686-clk",
313 },
314 .probe = max77686_clk_probe,
315 .remove = max77686_clk_remove,
316 .id_table = max77686_clk_id,
317 };
318
319 module_platform_driver(max77686_clk_driver);
320
321 MODULE_DESCRIPTION("MAXIM 77686 Clock Driver");
322 MODULE_AUTHOR("Jonghwa Lee <jonghwa3.lee@samsung.com>");
323 MODULE_LICENSE("GPL");
324