1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Clock driver for Palmas device.
4 *
5 * Copyright (c) 2013, NVIDIA Corporation.
6 * Copyright (c) 2013-2014 Texas Instruments, Inc.
7 *
8 * Author: Laxman Dewangan <ldewangan@nvidia.com>
9 * Peter Ujfalusi <peter.ujfalusi@ti.com>
10 */
11
12 #include <linux/clk.h>
13 #include <linux/clk-provider.h>
14 #include <linux/mfd/palmas.h>
15 #include <linux/module.h>
16 #include <linux/of.h>
17 #include <linux/of_device.h>
18 #include <linux/platform_device.h>
19 #include <linux/slab.h>
20
21 #define PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE1 1
22 #define PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE2 2
23 #define PALMAS_CLOCK_DT_EXT_CONTROL_NSLEEP 3
24
25 struct palmas_clk32k_desc {
26 const char *clk_name;
27 unsigned int control_reg;
28 unsigned int enable_mask;
29 unsigned int sleep_mask;
30 unsigned int sleep_reqstr_id;
31 int delay;
32 };
33
34 struct palmas_clock_info {
35 struct device *dev;
36 struct clk_hw hw;
37 struct palmas *palmas;
38 const struct palmas_clk32k_desc *clk_desc;
39 int ext_control_pin;
40 };
41
to_palmas_clks_info(struct clk_hw * hw)42 static inline struct palmas_clock_info *to_palmas_clks_info(struct clk_hw *hw)
43 {
44 return container_of(hw, struct palmas_clock_info, hw);
45 }
46
palmas_clks_recalc_rate(struct clk_hw * hw,unsigned long parent_rate)47 static unsigned long palmas_clks_recalc_rate(struct clk_hw *hw,
48 unsigned long parent_rate)
49 {
50 return 32768;
51 }
52
palmas_clks_prepare(struct clk_hw * hw)53 static int palmas_clks_prepare(struct clk_hw *hw)
54 {
55 struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
56 int ret;
57
58 ret = palmas_update_bits(cinfo->palmas, PALMAS_RESOURCE_BASE,
59 cinfo->clk_desc->control_reg,
60 cinfo->clk_desc->enable_mask,
61 cinfo->clk_desc->enable_mask);
62 if (ret < 0)
63 dev_err(cinfo->dev, "Reg 0x%02x update failed, %d\n",
64 cinfo->clk_desc->control_reg, ret);
65 else if (cinfo->clk_desc->delay)
66 udelay(cinfo->clk_desc->delay);
67
68 return ret;
69 }
70
palmas_clks_unprepare(struct clk_hw * hw)71 static void palmas_clks_unprepare(struct clk_hw *hw)
72 {
73 struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
74 int ret;
75
76 /*
77 * Clock can be disabled through external pin if it is externally
78 * controlled.
79 */
80 if (cinfo->ext_control_pin)
81 return;
82
83 ret = palmas_update_bits(cinfo->palmas, PALMAS_RESOURCE_BASE,
84 cinfo->clk_desc->control_reg,
85 cinfo->clk_desc->enable_mask, 0);
86 if (ret < 0)
87 dev_err(cinfo->dev, "Reg 0x%02x update failed, %d\n",
88 cinfo->clk_desc->control_reg, ret);
89 }
90
palmas_clks_is_prepared(struct clk_hw * hw)91 static int palmas_clks_is_prepared(struct clk_hw *hw)
92 {
93 struct palmas_clock_info *cinfo = to_palmas_clks_info(hw);
94 int ret;
95 u32 val;
96
97 if (cinfo->ext_control_pin)
98 return 1;
99
100 ret = palmas_read(cinfo->palmas, PALMAS_RESOURCE_BASE,
101 cinfo->clk_desc->control_reg, &val);
102 if (ret < 0) {
103 dev_err(cinfo->dev, "Reg 0x%02x read failed, %d\n",
104 cinfo->clk_desc->control_reg, ret);
105 return ret;
106 }
107 return !!(val & cinfo->clk_desc->enable_mask);
108 }
109
110 static const struct clk_ops palmas_clks_ops = {
111 .prepare = palmas_clks_prepare,
112 .unprepare = palmas_clks_unprepare,
113 .is_prepared = palmas_clks_is_prepared,
114 .recalc_rate = palmas_clks_recalc_rate,
115 };
116
117 struct palmas_clks_of_match_data {
118 struct clk_init_data init;
119 const struct palmas_clk32k_desc desc;
120 };
121
122 static const struct palmas_clks_of_match_data palmas_of_clk32kg = {
123 .init = {
124 .name = "clk32kg",
125 .ops = &palmas_clks_ops,
126 .flags = CLK_IGNORE_UNUSED,
127 },
128 .desc = {
129 .clk_name = "clk32kg",
130 .control_reg = PALMAS_CLK32KG_CTRL,
131 .enable_mask = PALMAS_CLK32KG_CTRL_MODE_ACTIVE,
132 .sleep_mask = PALMAS_CLK32KG_CTRL_MODE_SLEEP,
133 .sleep_reqstr_id = PALMAS_EXTERNAL_REQSTR_ID_CLK32KG,
134 .delay = 200,
135 },
136 };
137
138 static const struct palmas_clks_of_match_data palmas_of_clk32kgaudio = {
139 .init = {
140 .name = "clk32kgaudio",
141 .ops = &palmas_clks_ops,
142 .flags = CLK_IGNORE_UNUSED,
143 },
144 .desc = {
145 .clk_name = "clk32kgaudio",
146 .control_reg = PALMAS_CLK32KGAUDIO_CTRL,
147 .enable_mask = PALMAS_CLK32KG_CTRL_MODE_ACTIVE,
148 .sleep_mask = PALMAS_CLK32KG_CTRL_MODE_SLEEP,
149 .sleep_reqstr_id = PALMAS_EXTERNAL_REQSTR_ID_CLK32KGAUDIO,
150 .delay = 200,
151 },
152 };
153
154 static const struct of_device_id palmas_clks_of_match[] = {
155 {
156 .compatible = "ti,palmas-clk32kg",
157 .data = &palmas_of_clk32kg,
158 },
159 {
160 .compatible = "ti,palmas-clk32kgaudio",
161 .data = &palmas_of_clk32kgaudio,
162 },
163 { },
164 };
165 MODULE_DEVICE_TABLE(of, palmas_clks_of_match);
166
palmas_clks_get_clk_data(struct platform_device * pdev,struct palmas_clock_info * cinfo)167 static void palmas_clks_get_clk_data(struct platform_device *pdev,
168 struct palmas_clock_info *cinfo)
169 {
170 struct device_node *node = pdev->dev.of_node;
171 unsigned int prop;
172 int ret;
173
174 ret = of_property_read_u32(node, "ti,external-sleep-control",
175 &prop);
176 if (ret)
177 return;
178
179 switch (prop) {
180 case PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE1:
181 prop = PALMAS_EXT_CONTROL_ENABLE1;
182 break;
183 case PALMAS_CLOCK_DT_EXT_CONTROL_ENABLE2:
184 prop = PALMAS_EXT_CONTROL_ENABLE2;
185 break;
186 case PALMAS_CLOCK_DT_EXT_CONTROL_NSLEEP:
187 prop = PALMAS_EXT_CONTROL_NSLEEP;
188 break;
189 default:
190 dev_warn(&pdev->dev, "%pOFn: Invalid ext control option: %u\n",
191 node, prop);
192 prop = 0;
193 break;
194 }
195 cinfo->ext_control_pin = prop;
196 }
197
palmas_clks_init_configure(struct palmas_clock_info * cinfo)198 static int palmas_clks_init_configure(struct palmas_clock_info *cinfo)
199 {
200 int ret;
201
202 ret = palmas_update_bits(cinfo->palmas, PALMAS_RESOURCE_BASE,
203 cinfo->clk_desc->control_reg,
204 cinfo->clk_desc->sleep_mask, 0);
205 if (ret < 0) {
206 dev_err(cinfo->dev, "Reg 0x%02x update failed, %d\n",
207 cinfo->clk_desc->control_reg, ret);
208 return ret;
209 }
210
211 if (cinfo->ext_control_pin) {
212 ret = clk_prepare(cinfo->hw.clk);
213 if (ret < 0) {
214 dev_err(cinfo->dev, "Clock prep failed, %d\n", ret);
215 return ret;
216 }
217
218 ret = palmas_ext_control_req_config(cinfo->palmas,
219 cinfo->clk_desc->sleep_reqstr_id,
220 cinfo->ext_control_pin, true);
221 if (ret < 0) {
222 dev_err(cinfo->dev, "Ext config for %s failed, %d\n",
223 cinfo->clk_desc->clk_name, ret);
224 clk_unprepare(cinfo->hw.clk);
225 return ret;
226 }
227 }
228
229 return ret;
230 }
palmas_clks_probe(struct platform_device * pdev)231 static int palmas_clks_probe(struct platform_device *pdev)
232 {
233 struct palmas *palmas = dev_get_drvdata(pdev->dev.parent);
234 struct device_node *node = pdev->dev.of_node;
235 const struct palmas_clks_of_match_data *match_data;
236 struct palmas_clock_info *cinfo;
237 int ret;
238
239 match_data = of_device_get_match_data(&pdev->dev);
240 if (!match_data)
241 return 1;
242
243 cinfo = devm_kzalloc(&pdev->dev, sizeof(*cinfo), GFP_KERNEL);
244 if (!cinfo)
245 return -ENOMEM;
246
247 palmas_clks_get_clk_data(pdev, cinfo);
248 platform_set_drvdata(pdev, cinfo);
249
250 cinfo->dev = &pdev->dev;
251 cinfo->palmas = palmas;
252
253 cinfo->clk_desc = &match_data->desc;
254 cinfo->hw.init = &match_data->init;
255 ret = devm_clk_hw_register(&pdev->dev, &cinfo->hw);
256 if (ret) {
257 dev_err(&pdev->dev, "Fail to register clock %s, %d\n",
258 match_data->desc.clk_name, ret);
259 return ret;
260 }
261
262 ret = palmas_clks_init_configure(cinfo);
263 if (ret < 0) {
264 dev_err(&pdev->dev, "Clock config failed, %d\n", ret);
265 return ret;
266 }
267
268 ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, &cinfo->hw);
269 if (ret < 0)
270 dev_err(&pdev->dev, "Fail to add clock driver, %d\n", ret);
271 return ret;
272 }
273
palmas_clks_remove(struct platform_device * pdev)274 static int palmas_clks_remove(struct platform_device *pdev)
275 {
276 of_clk_del_provider(pdev->dev.of_node);
277 return 0;
278 }
279
280 static struct platform_driver palmas_clks_driver = {
281 .driver = {
282 .name = "palmas-clk",
283 .of_match_table = palmas_clks_of_match,
284 },
285 .probe = palmas_clks_probe,
286 .remove = palmas_clks_remove,
287 };
288
289 module_platform_driver(palmas_clks_driver);
290
291 MODULE_DESCRIPTION("Clock driver for Palmas Series Devices");
292 MODULE_ALIAS("platform:palmas-clk");
293 MODULE_AUTHOR("Peter Ujfalusi <peter.ujfalusi@ti.com>");
294 MODULE_LICENSE("GPL v2");
295