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10#include <linux/err.h>
11#include <linux/i2c.h>
12#include <linux/mfd/lp3943.h>
13#include <linux/module.h>
14#include <linux/platform_device.h>
15#include <linux/pwm.h>
16#include <linux/slab.h>
17
18#define LP3943_MAX_DUTY 255
19#define LP3943_MIN_PERIOD 6250
20#define LP3943_MAX_PERIOD 1600000
21
22struct lp3943_pwm {
23 struct pwm_chip chip;
24 struct lp3943 *lp3943;
25 struct lp3943_platform_data *pdata;
26};
27
28static inline struct lp3943_pwm *to_lp3943_pwm(struct pwm_chip *_chip)
29{
30 return container_of(_chip, struct lp3943_pwm, chip);
31}
32
33static struct lp3943_pwm_map *
34lp3943_pwm_request_map(struct lp3943_pwm *lp3943_pwm, int hwpwm)
35{
36 struct lp3943_platform_data *pdata = lp3943_pwm->pdata;
37 struct lp3943 *lp3943 = lp3943_pwm->lp3943;
38 struct lp3943_pwm_map *pwm_map;
39 int i, offset;
40
41 pwm_map = kzalloc(sizeof(*pwm_map), GFP_KERNEL);
42 if (!pwm_map)
43 return ERR_PTR(-ENOMEM);
44
45 pwm_map->output = pdata->pwms[hwpwm]->output;
46 pwm_map->num_outputs = pdata->pwms[hwpwm]->num_outputs;
47
48 for (i = 0; i < pwm_map->num_outputs; i++) {
49 offset = pwm_map->output[i];
50
51
52 if (test_and_set_bit(offset, &lp3943->pin_used)) {
53 kfree(pwm_map);
54 return ERR_PTR(-EBUSY);
55 }
56 }
57
58 return pwm_map;
59}
60
61static int lp3943_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
62{
63 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
64 struct lp3943_pwm_map *pwm_map;
65
66 pwm_map = lp3943_pwm_request_map(lp3943_pwm, pwm->hwpwm);
67 if (IS_ERR(pwm_map))
68 return PTR_ERR(pwm_map);
69
70 return pwm_set_chip_data(pwm, pwm_map);
71}
72
73static void lp3943_pwm_free_map(struct lp3943_pwm *lp3943_pwm,
74 struct lp3943_pwm_map *pwm_map)
75{
76 struct lp3943 *lp3943 = lp3943_pwm->lp3943;
77 int i, offset;
78
79 for (i = 0; i < pwm_map->num_outputs; i++) {
80 offset = pwm_map->output[i];
81 clear_bit(offset, &lp3943->pin_used);
82 }
83
84 kfree(pwm_map);
85}
86
87static void lp3943_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
88{
89 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
90 struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm);
91
92 lp3943_pwm_free_map(lp3943_pwm, pwm_map);
93}
94
95static int lp3943_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
96 int duty_ns, int period_ns)
97{
98 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
99 struct lp3943 *lp3943 = lp3943_pwm->lp3943;
100 u8 val, reg_duty, reg_prescale;
101 int err;
102
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111
112
113 if (pwm->hwpwm == 0) {
114 reg_prescale = LP3943_REG_PRESCALE0;
115 reg_duty = LP3943_REG_PWM0;
116 } else {
117 reg_prescale = LP3943_REG_PRESCALE1;
118 reg_duty = LP3943_REG_PWM1;
119 }
120
121 period_ns = clamp(period_ns, LP3943_MIN_PERIOD, LP3943_MAX_PERIOD);
122 val = (u8)(period_ns / LP3943_MIN_PERIOD - 1);
123
124 err = lp3943_write_byte(lp3943, reg_prescale, val);
125 if (err)
126 return err;
127
128 val = (u8)(duty_ns * LP3943_MAX_DUTY / period_ns);
129
130 return lp3943_write_byte(lp3943, reg_duty, val);
131}
132
133static int lp3943_pwm_set_mode(struct lp3943_pwm *lp3943_pwm,
134 struct lp3943_pwm_map *pwm_map,
135 u8 val)
136{
137 struct lp3943 *lp3943 = lp3943_pwm->lp3943;
138 const struct lp3943_reg_cfg *mux = lp3943->mux_cfg;
139 int i, index, err;
140
141 for (i = 0; i < pwm_map->num_outputs; i++) {
142 index = pwm_map->output[i];
143 err = lp3943_update_bits(lp3943, mux[index].reg,
144 mux[index].mask,
145 val << mux[index].shift);
146 if (err)
147 return err;
148 }
149
150 return 0;
151}
152
153static int lp3943_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
154{
155 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
156 struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm);
157 u8 val;
158
159 if (pwm->hwpwm == 0)
160 val = LP3943_DIM_PWM0;
161 else
162 val = LP3943_DIM_PWM1;
163
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168
169 return lp3943_pwm_set_mode(lp3943_pwm, pwm_map, val);
170}
171
172static void lp3943_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
173{
174 struct lp3943_pwm *lp3943_pwm = to_lp3943_pwm(chip);
175 struct lp3943_pwm_map *pwm_map = pwm_get_chip_data(pwm);
176
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181
182 lp3943_pwm_set_mode(lp3943_pwm, pwm_map, LP3943_GPIO_OUT_HIGH);
183}
184
185static const struct pwm_ops lp3943_pwm_ops = {
186 .request = lp3943_pwm_request,
187 .free = lp3943_pwm_free,
188 .config = lp3943_pwm_config,
189 .enable = lp3943_pwm_enable,
190 .disable = lp3943_pwm_disable,
191 .owner = THIS_MODULE,
192};
193
194static int lp3943_pwm_parse_dt(struct device *dev,
195 struct lp3943_pwm *lp3943_pwm)
196{
197 static const char * const name[] = { "ti,pwm0", "ti,pwm1", };
198 struct device_node *node = dev->of_node;
199 struct lp3943_platform_data *pdata;
200 struct lp3943_pwm_map *pwm_map;
201 enum lp3943_pwm_output *output;
202 int i, err, proplen, count = 0;
203 u32 num_outputs;
204
205 if (!node)
206 return -EINVAL;
207
208 pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
209 if (!pdata)
210 return -ENOMEM;
211
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216
217 for (i = 0; i < LP3943_NUM_PWMS; i++) {
218 if (!of_get_property(node, name[i], &proplen))
219 continue;
220
221 num_outputs = proplen / sizeof(u32);
222 if (num_outputs == 0)
223 continue;
224
225 output = devm_kcalloc(dev, num_outputs, sizeof(*output),
226 GFP_KERNEL);
227 if (!output)
228 return -ENOMEM;
229
230 err = of_property_read_u32_array(node, name[i], output,
231 num_outputs);
232 if (err)
233 return err;
234
235 pwm_map = devm_kzalloc(dev, sizeof(*pwm_map), GFP_KERNEL);
236 if (!pwm_map)
237 return -ENOMEM;
238
239 pwm_map->output = output;
240 pwm_map->num_outputs = num_outputs;
241 pdata->pwms[i] = pwm_map;
242
243 count++;
244 }
245
246 if (count == 0)
247 return -ENODATA;
248
249 lp3943_pwm->pdata = pdata;
250 return 0;
251}
252
253static int lp3943_pwm_probe(struct platform_device *pdev)
254{
255 struct lp3943 *lp3943 = dev_get_drvdata(pdev->dev.parent);
256 struct lp3943_pwm *lp3943_pwm;
257 int ret;
258
259 lp3943_pwm = devm_kzalloc(&pdev->dev, sizeof(*lp3943_pwm), GFP_KERNEL);
260 if (!lp3943_pwm)
261 return -ENOMEM;
262
263 lp3943_pwm->pdata = lp3943->pdata;
264 if (!lp3943_pwm->pdata) {
265 if (IS_ENABLED(CONFIG_OF))
266 ret = lp3943_pwm_parse_dt(&pdev->dev, lp3943_pwm);
267 else
268 ret = -ENODEV;
269
270 if (ret)
271 return ret;
272 }
273
274 lp3943_pwm->lp3943 = lp3943;
275 lp3943_pwm->chip.dev = &pdev->dev;
276 lp3943_pwm->chip.ops = &lp3943_pwm_ops;
277 lp3943_pwm->chip.npwm = LP3943_NUM_PWMS;
278
279 platform_set_drvdata(pdev, lp3943_pwm);
280
281 return pwmchip_add(&lp3943_pwm->chip);
282}
283
284static int lp3943_pwm_remove(struct platform_device *pdev)
285{
286 struct lp3943_pwm *lp3943_pwm = platform_get_drvdata(pdev);
287
288 return pwmchip_remove(&lp3943_pwm->chip);
289}
290
291#ifdef CONFIG_OF
292static const struct of_device_id lp3943_pwm_of_match[] = {
293 { .compatible = "ti,lp3943-pwm", },
294 { }
295};
296MODULE_DEVICE_TABLE(of, lp3943_pwm_of_match);
297#endif
298
299static struct platform_driver lp3943_pwm_driver = {
300 .probe = lp3943_pwm_probe,
301 .remove = lp3943_pwm_remove,
302 .driver = {
303 .name = "lp3943-pwm",
304 .of_match_table = of_match_ptr(lp3943_pwm_of_match),
305 },
306};
307module_platform_driver(lp3943_pwm_driver);
308
309MODULE_DESCRIPTION("LP3943 PWM driver");
310MODULE_ALIAS("platform:lp3943-pwm");
311MODULE_AUTHOR("Milo Kim");
312MODULE_LICENSE("GPL");
313
