This source file includes following definitions.
- to_tegra_pwm_chip
- pwm_readl
- pwm_writel
- tegra_pwm_config
- tegra_pwm_enable
- tegra_pwm_disable
- tegra_pwm_probe
- tegra_pwm_remove
- tegra_pwm_suspend
- tegra_pwm_resume
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11 #include <linux/clk.h>
12 #include <linux/err.h>
13 #include <linux/io.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/of_device.h>
17 #include <linux/pwm.h>
18 #include <linux/platform_device.h>
19 #include <linux/pinctrl/consumer.h>
20 #include <linux/slab.h>
21 #include <linux/reset.h>
22
23 #define PWM_ENABLE (1 << 31)
24 #define PWM_DUTY_WIDTH 8
25 #define PWM_DUTY_SHIFT 16
26 #define PWM_SCALE_WIDTH 13
27 #define PWM_SCALE_SHIFT 0
28
29 struct tegra_pwm_soc {
30 unsigned int num_channels;
31
32
33 unsigned long max_frequency;
34 };
35
36 struct tegra_pwm_chip {
37 struct pwm_chip chip;
38 struct device *dev;
39
40 struct clk *clk;
41 struct reset_control*rst;
42
43 unsigned long clk_rate;
44
45 void __iomem *regs;
46
47 const struct tegra_pwm_soc *soc;
48 };
49
50 static inline struct tegra_pwm_chip *to_tegra_pwm_chip(struct pwm_chip *chip)
51 {
52 return container_of(chip, struct tegra_pwm_chip, chip);
53 }
54
55 static inline u32 pwm_readl(struct tegra_pwm_chip *chip, unsigned int num)
56 {
57 return readl(chip->regs + (num << 4));
58 }
59
60 static inline void pwm_writel(struct tegra_pwm_chip *chip, unsigned int num,
61 unsigned long val)
62 {
63 writel(val, chip->regs + (num << 4));
64 }
65
66 static int tegra_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
67 int duty_ns, int period_ns)
68 {
69 struct tegra_pwm_chip *pc = to_tegra_pwm_chip(chip);
70 unsigned long long c = duty_ns, hz;
71 unsigned long rate;
72 u32 val = 0;
73 int err;
74
75
76
77
78
79
80 c *= (1 << PWM_DUTY_WIDTH);
81 c = DIV_ROUND_CLOSEST_ULL(c, period_ns);
82
83 val = (u32)c << PWM_DUTY_SHIFT;
84
85
86
87
88
89 rate = pc->clk_rate >> PWM_DUTY_WIDTH;
90
91
92 hz = DIV_ROUND_CLOSEST_ULL(100ULL * NSEC_PER_SEC, period_ns);
93 rate = DIV_ROUND_CLOSEST_ULL(100ULL * rate, hz);
94
95
96
97
98
99
100 if (rate > 0)
101 rate--;
102
103
104
105
106
107 if (rate >> PWM_SCALE_WIDTH)
108 return -EINVAL;
109
110 val |= rate << PWM_SCALE_SHIFT;
111
112
113
114
115
116 if (!pwm_is_enabled(pwm)) {
117 err = clk_prepare_enable(pc->clk);
118 if (err < 0)
119 return err;
120 } else
121 val |= PWM_ENABLE;
122
123 pwm_writel(pc, pwm->hwpwm, val);
124
125
126
127
128 if (!pwm_is_enabled(pwm))
129 clk_disable_unprepare(pc->clk);
130
131 return 0;
132 }
133
134 static int tegra_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
135 {
136 struct tegra_pwm_chip *pc = to_tegra_pwm_chip(chip);
137 int rc = 0;
138 u32 val;
139
140 rc = clk_prepare_enable(pc->clk);
141 if (rc < 0)
142 return rc;
143
144 val = pwm_readl(pc, pwm->hwpwm);
145 val |= PWM_ENABLE;
146 pwm_writel(pc, pwm->hwpwm, val);
147
148 return 0;
149 }
150
151 static void tegra_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
152 {
153 struct tegra_pwm_chip *pc = to_tegra_pwm_chip(chip);
154 u32 val;
155
156 val = pwm_readl(pc, pwm->hwpwm);
157 val &= ~PWM_ENABLE;
158 pwm_writel(pc, pwm->hwpwm, val);
159
160 clk_disable_unprepare(pc->clk);
161 }
162
163 static const struct pwm_ops tegra_pwm_ops = {
164 .config = tegra_pwm_config,
165 .enable = tegra_pwm_enable,
166 .disable = tegra_pwm_disable,
167 .owner = THIS_MODULE,
168 };
169
170 static int tegra_pwm_probe(struct platform_device *pdev)
171 {
172 struct tegra_pwm_chip *pwm;
173 struct resource *r;
174 int ret;
175
176 pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
177 if (!pwm)
178 return -ENOMEM;
179
180 pwm->soc = of_device_get_match_data(&pdev->dev);
181 pwm->dev = &pdev->dev;
182
183 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
184 pwm->regs = devm_ioremap_resource(&pdev->dev, r);
185 if (IS_ERR(pwm->regs))
186 return PTR_ERR(pwm->regs);
187
188 platform_set_drvdata(pdev, pwm);
189
190 pwm->clk = devm_clk_get(&pdev->dev, NULL);
191 if (IS_ERR(pwm->clk))
192 return PTR_ERR(pwm->clk);
193
194
195 ret = clk_set_rate(pwm->clk, pwm->soc->max_frequency);
196 if (ret < 0) {
197 dev_err(&pdev->dev, "Failed to set max frequency: %d\n", ret);
198 return ret;
199 }
200
201
202
203
204
205
206 pwm->clk_rate = clk_get_rate(pwm->clk);
207
208 pwm->rst = devm_reset_control_get_exclusive(&pdev->dev, "pwm");
209 if (IS_ERR(pwm->rst)) {
210 ret = PTR_ERR(pwm->rst);
211 dev_err(&pdev->dev, "Reset control is not found: %d\n", ret);
212 return ret;
213 }
214
215 reset_control_deassert(pwm->rst);
216
217 pwm->chip.dev = &pdev->dev;
218 pwm->chip.ops = &tegra_pwm_ops;
219 pwm->chip.base = -1;
220 pwm->chip.npwm = pwm->soc->num_channels;
221
222 ret = pwmchip_add(&pwm->chip);
223 if (ret < 0) {
224 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
225 reset_control_assert(pwm->rst);
226 return ret;
227 }
228
229 return 0;
230 }
231
232 static int tegra_pwm_remove(struct platform_device *pdev)
233 {
234 struct tegra_pwm_chip *pc = platform_get_drvdata(pdev);
235 unsigned int i;
236 int err;
237
238 if (WARN_ON(!pc))
239 return -ENODEV;
240
241 err = clk_prepare_enable(pc->clk);
242 if (err < 0)
243 return err;
244
245 for (i = 0; i < pc->chip.npwm; i++) {
246 struct pwm_device *pwm = &pc->chip.pwms[i];
247
248 if (!pwm_is_enabled(pwm))
249 if (clk_prepare_enable(pc->clk) < 0)
250 continue;
251
252 pwm_writel(pc, i, 0);
253
254 clk_disable_unprepare(pc->clk);
255 }
256
257 reset_control_assert(pc->rst);
258 clk_disable_unprepare(pc->clk);
259
260 return pwmchip_remove(&pc->chip);
261 }
262
263 #ifdef CONFIG_PM_SLEEP
264 static int tegra_pwm_suspend(struct device *dev)
265 {
266 return pinctrl_pm_select_sleep_state(dev);
267 }
268
269 static int tegra_pwm_resume(struct device *dev)
270 {
271 return pinctrl_pm_select_default_state(dev);
272 }
273 #endif
274
275 static const struct tegra_pwm_soc tegra20_pwm_soc = {
276 .num_channels = 4,
277 .max_frequency = 48000000UL,
278 };
279
280 static const struct tegra_pwm_soc tegra186_pwm_soc = {
281 .num_channels = 1,
282 .max_frequency = 102000000UL,
283 };
284
285 static const struct of_device_id tegra_pwm_of_match[] = {
286 { .compatible = "nvidia,tegra20-pwm", .data = &tegra20_pwm_soc },
287 { .compatible = "nvidia,tegra186-pwm", .data = &tegra186_pwm_soc },
288 { }
289 };
290 MODULE_DEVICE_TABLE(of, tegra_pwm_of_match);
291
292 static const struct dev_pm_ops tegra_pwm_pm_ops = {
293 SET_SYSTEM_SLEEP_PM_OPS(tegra_pwm_suspend, tegra_pwm_resume)
294 };
295
296 static struct platform_driver tegra_pwm_driver = {
297 .driver = {
298 .name = "tegra-pwm",
299 .of_match_table = tegra_pwm_of_match,
300 .pm = &tegra_pwm_pm_ops,
301 },
302 .probe = tegra_pwm_probe,
303 .remove = tegra_pwm_remove,
304 };
305
306 module_platform_driver(tegra_pwm_driver);
307
308 MODULE_LICENSE("GPL");
309 MODULE_AUTHOR("NVIDIA Corporation");
310 MODULE_ALIAS("platform:tegra-pwm");