1 /*
2 * Clock driver for Palmas device.
3 *
4 * Copyright (c) 2013, NVIDIA Corporation.
5 * Copyright (c) 2013-2014 Texas Instruments, Inc.
6 *
7 * Author: Laxman Dewangan <ldewangan@nvidia.com>
8 * Peter Ujfalusi <peter.ujfalusi@ti.com>
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation version 2.
13 *
14 * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
15 * whether express or implied; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 */
19
20 #include <linux/clk.h>
21 #include <linux/clk-provider.h>
22 #include <linux/mfd/palmas.h>
23 #include <linux/module.h>
24 #include <linux/of.h>
25 #include <linux/of_device.h>
26 #include <linux/platform_device.h>
27 #include <linux/slab.h>
28
29 #define PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE1 1
30 #define PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE2 2
31 #define PALMAS_CLOCK_DT_EXT_CONTROL_NSLEEP 3
32
33 struct palmas_clk32k_desc {
34 const char *clk_name;
35 unsigned int control_reg;
36 unsigned int enable_mask;
37 unsigned int sleep_mask;
38 unsigned int sleep_reqstr_id;
39 int delay;
40 };
41
42 struct palmas_clock_info {
43 struct device *dev;
44 struct clk_hw hw;
45 struct palmas *palmas;
46 const struct palmas_clk32k_desc *clk_desc;
47 int ext_control_pin;
48 };
49
to_palmas_clks_info(struct clk_hw * hw)50 static inline struct palmas_clock_info *to_palmas_clks_info(struct clk_hw *hw)
51 {
52 return container_of(hw, struct palmas_clock_info, hw);
53 }
54
palmas_clks_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)55 static unsigned long palmas_clks_recalc_rate(struct clk_hw *hw,
56 unsigned long parent_rate)
57 {
58 return 32768;
59 }
60
palmas_clks_prepare(struct clk_hw * hw)61 static int palmas_clks_prepare(struct clk_hw *hw)
62 {
63 struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
64 int ret;
65
66 ret = palmas_update_bits(cinfo->palmas, PALMAS_RESOURCE_BASE,
67 cinfo->clk_desc->control_reg,
68 cinfo->clk_desc->enable_mask,
69 cinfo->clk_desc->enable_mask);
70 if (ret < 0)
71 dev_err(cinfo->dev, "Reg 0x%02x update failed, %d\n",
72 cinfo->clk_desc->control_reg, ret);
73 else if (cinfo->clk_desc->delay)
74 udelay(cinfo->clk_desc->delay);
75
76 return ret;
77 }
78
palmas_clks_unprepare(struct clk_hw * hw)79 static void palmas_clks_unprepare(struct clk_hw *hw)
80 {
81 struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
82 int ret;
83
84 /*
85 * Clock can be disabled through external pin if it is externally
86 * controlled.
87 */
88 if (cinfo->ext_control_pin)
89 return;
90
91 ret = palmas_update_bits(cinfo->palmas, PALMAS_RESOURCE_BASE,
92 cinfo->clk_desc->control_reg,
93 cinfo->clk_desc->enable_mask, 0);
94 if (ret < 0)
95 dev_err(cinfo->dev, "Reg 0x%02x update failed, %d\n",
96 cinfo->clk_desc->control_reg, ret);
97 }
98
palmas_clks_is_prepared(struct clk_hw * hw)99 static int palmas_clks_is_prepared(struct clk_hw *hw)
100 {
101 struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
102 int ret;
103 u32 val;
104
105 if (cinfo->ext_control_pin)
106 return 1;
107
108 ret = palmas_read(cinfo->palmas, PALMAS_RESOURCE_BASE,
109 cinfo->clk_desc->control_reg, &val);
110 if (ret < 0) {
111 dev_err(cinfo->dev, "Reg 0x%02x read failed, %d\n",
112 cinfo->clk_desc->control_reg, ret);
113 return ret;
114 }
115 return !!(val & cinfo->clk_desc->enable_mask);
116 }
117
118 static const struct clk_ops palmas_clks_ops = {
119 .prepare = palmas_clks_prepare,
120 .unprepare = palmas_clks_unprepare,
121 .is_prepared = palmas_clks_is_prepared,
122 .recalc_rate = palmas_clks_recalc_rate,
123 };
124
125 struct palmas_clks_of_match_data {
126 struct clk_init_data init;
127 const struct palmas_clk32k_desc desc;
128 };
129
130 static const struct palmas_clks_of_match_data palmas_of_clk32kg = {
131 .init = {
132 .name = "clk32kg",
133 .ops = &palmas_clks_ops,
134 .flags = CLK_IGNORE_UNUSED,
135 },
136 .desc = {
137 .clk_name = "clk32kg",
138 .control_reg = PALMAS_CLK32KG_CTRL,
139 .enable_mask = PALMAS_CLK32KG_CTRL_MODE_ACTIVE,
140 .sleep_mask = PALMAS_CLK32KG_CTRL_MODE_SLEEP,
141 .sleep_reqstr_id = PALMAS_EXTERNAL_REQSTR_ID_CLK32KG,
142 .delay = 200,
143 },
144 };
145
146 static const struct palmas_clks_of_match_data palmas_of_clk32kgaudio = {
147 .init = {
148 .name = "clk32kgaudio",
149 .ops = &palmas_clks_ops,
150 .flags = CLK_IGNORE_UNUSED,
151 },
152 .desc = {
153 .clk_name = "clk32kgaudio",
154 .control_reg = PALMAS_CLK32KGAUDIO_CTRL,
155 .enable_mask = PALMAS_CLK32KG_CTRL_MODE_ACTIVE,
156 .sleep_mask = PALMAS_CLK32KG_CTRL_MODE_SLEEP,
157 .sleep_reqstr_id = PALMAS_EXTERNAL_REQSTR_ID_CLK32KGAUDIO,
158 .delay = 200,
159 },
160 };
161
162 static const struct of_device_id palmas_clks_of_match[] = {
163 {
164 .compatible = "ti,palmas-clk32kg",
165 .data = &palmas_of_clk32kg,
166 },
167 {
168 .compatible = "ti,palmas-clk32kgaudio",
169 .data = &palmas_of_clk32kgaudio,
170 },
171 { },
172 };
173 MODULE_DEVICE_TABLE(of, palmas_clks_of_match);
174
palmas_clks_get_clk_data(struct platform_device * pdev,struct palmas_clock_info * cinfo)175 static void palmas_clks_get_clk_data(struct platform_device *pdev,
176 struct palmas_clock_info *cinfo)
177 {
178 struct device_node *node = pdev->dev.of_node;
179 unsigned int prop;
180 int ret;
181
182 ret = of_property_read_u32(node, "ti,external-sleep-control",
183 &prop);
184 if (ret)
185 return;
186
187 switch (prop) {
188 case PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE1:
189 prop = PALMAS_EXT_CONTROL_ENABLE1;
190 break;
191 case PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE2:
192 prop = PALMAS_EXT_CONTROL_ENABLE2;
193 break;
194 case PALMAS_CLOCK_DT_EXT_CONTROL_NSLEEP:
195 prop = PALMAS_EXT_CONTROL_NSLEEP;
196 break;
197 default:
198 dev_warn(&pdev->dev, "%pOFn: Invalid ext control option: %u\n",
199 node, prop);
200 prop = 0;
201 break;
202 }
203 cinfo->ext_control_pin = prop;
204 }
205
palmas_clks_init_configure(struct palmas_clock_info * cinfo)206 static int palmas_clks_init_configure(struct palmas_clock_info *cinfo)
207 {
208 int ret;
209
210 ret = palmas_update_bits(cinfo->palmas, PALMAS_RESOURCE_BASE,
211 cinfo->clk_desc->control_reg,
212 cinfo->clk_desc->sleep_mask, 0);
213 if (ret < 0) {
214 dev_err(cinfo->dev, "Reg 0x%02x update failed, %d\n",
215 cinfo->clk_desc->control_reg, ret);
216 return ret;
217 }
218
219 if (cinfo->ext_control_pin) {
220 ret = clk_prepare(cinfo->hw.clk);
221 if (ret < 0) {
222 dev_err(cinfo->dev, "Clock prep failed, %d\n", ret);
223 return ret;
224 }
225
226 ret = palmas_ext_control_req_config(cinfo->palmas,
227 cinfo->clk_desc->sleep_reqstr_id,
228 cinfo->ext_control_pin, true);
229 if (ret < 0) {
230 dev_err(cinfo->dev, "Ext config for %s failed, %d\n",
231 cinfo->clk_desc->clk_name, ret);
232 clk_unprepare(cinfo->hw.clk);
233 return ret;
234 }
235 }
236
237 return ret;
238 }
palmas_clks_probe(struct platform_device * pdev)239 static int palmas_clks_probe(struct platform_device *pdev)
240 {
241 struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
242 struct device_node *node = pdev->dev.of_node;
243 const struct palmas_clks_of_match_data *match_data;
244 struct palmas_clock_info *cinfo;
245 int ret;
246
247 match_data = of_device_get_match_data(&pdev->dev);
248 if (!match_data)
249 return 1;
250
251 cinfo = devm_kzalloc(&pdev->dev, sizeof(*cinfo), GFP_KERNEL);
252 if (!cinfo)
253 return -ENOMEM;
254
255 palmas_clks_get_clk_data(pdev, cinfo);
256 platform_set_drvdata(pdev, cinfo);
257
258 cinfo->dev = &pdev->dev;
259 cinfo->palmas = palmas;
260
261 cinfo->clk_desc = &match_data->desc;
262 cinfo->hw.init = &match_data->init;
263 ret = devm_clk_hw_register(&pdev->dev, &cinfo->hw);
264 if (ret) {
265 dev_err(&pdev->dev, "Fail to register clock %s, %d\n",
266 match_data->desc.clk_name, ret);
267 return ret;
268 }
269
270 ret = palmas_clks_init_configure(cinfo);
271 if (ret < 0) {
272 dev_err(&pdev->dev, "Clock config failed, %d\n", ret);
273 return ret;
274 }
275
276 ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, &cinfo->hw);
277 if (ret < 0)
278 dev_err(&pdev->dev, "Fail to add clock driver, %d\n", ret);
279 return ret;
280 }
281
palmas_clks_remove(struct platform_device * pdev)282 static int palmas_clks_remove(struct platform_device *pdev)
283 {
284 of_clk_del_provider(pdev->dev.of_node);
285 return 0;
286 }
287
288 static struct platform_driver palmas_clks_driver = {
289 .driver = {
290 .name = "palmas-clk",
291 .of_match_table = palmas_clks_of_match,
292 },
293 .probe = palmas_clks_probe,
294 .remove = palmas_clks_remove,
295 };
296
297 module_platform_driver(palmas_clks_driver);
298
299 MODULE_DESCRIPTION("Clock driver for Palmas Series Devices");
300 MODULE_ALIAS("platform:palmas-clk");
301 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
302 MODULE_LICENSE("GPL v2");
303