This source file includes following definitions.
- to_pxa_pwm_chip
- pxa_pwm_config
- pxa_pwm_enable
- pxa_pwm_disable
- pxa_pwm_get_id_dt
- pxa_pwm_of_xlate
- pwm_probe
- pwm_remove
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11 #include <linux/module.h>
12 #include <linux/kernel.h>
13 #include <linux/platform_device.h>
14 #include <linux/slab.h>
15 #include <linux/err.h>
16 #include <linux/clk.h>
17 #include <linux/io.h>
18 #include <linux/pwm.h>
19 #include <linux/of_device.h>
20
21 #include <asm/div64.h>
22
23 #define HAS_SECONDARY_PWM 0x10
24
25 static const struct platform_device_id pwm_id_table[] = {
26
27 { "pxa25x-pwm", 0 },
28 { "pxa27x-pwm", HAS_SECONDARY_PWM },
29 { "pxa168-pwm", 0 },
30 { "pxa910-pwm", 0 },
31 { },
32 };
33 MODULE_DEVICE_TABLE(platform, pwm_id_table);
34
35
36 #define PWMCR (0x00)
37 #define PWMDCR (0x04)
38 #define PWMPCR (0x08)
39
40 #define PWMCR_SD (1 << 6)
41 #define PWMDCR_FD (1 << 10)
42
43 struct pxa_pwm_chip {
44 struct pwm_chip chip;
45 struct device *dev;
46
47 struct clk *clk;
48 void __iomem *mmio_base;
49 };
50
51 static inline struct pxa_pwm_chip *to_pxa_pwm_chip(struct pwm_chip *chip)
52 {
53 return container_of(chip, struct pxa_pwm_chip, chip);
54 }
55
56
57
58
59
60 static int pxa_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
61 int duty_ns, int period_ns)
62 {
63 struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
64 unsigned long long c;
65 unsigned long period_cycles, prescale, pv, dc;
66 unsigned long offset;
67 int rc;
68
69 offset = pwm->hwpwm ? 0x10 : 0;
70
71 c = clk_get_rate(pc->clk);
72 c = c * period_ns;
73 do_div(c, 1000000000);
74 period_cycles = c;
75
76 if (period_cycles < 1)
77 period_cycles = 1;
78 prescale = (period_cycles - 1) / 1024;
79 pv = period_cycles / (prescale + 1) - 1;
80
81 if (prescale > 63)
82 return -EINVAL;
83
84 if (duty_ns == period_ns)
85 dc = PWMDCR_FD;
86 else
87 dc = (pv + 1) * duty_ns / period_ns;
88
89
90
91
92 rc = clk_prepare_enable(pc->clk);
93 if (rc < 0)
94 return rc;
95
96 writel(prescale, pc->mmio_base + offset + PWMCR);
97 writel(dc, pc->mmio_base + offset + PWMDCR);
98 writel(pv, pc->mmio_base + offset + PWMPCR);
99
100 clk_disable_unprepare(pc->clk);
101 return 0;
102 }
103
104 static int pxa_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
105 {
106 struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
107
108 return clk_prepare_enable(pc->clk);
109 }
110
111 static void pxa_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
112 {
113 struct pxa_pwm_chip *pc = to_pxa_pwm_chip(chip);
114
115 clk_disable_unprepare(pc->clk);
116 }
117
118 static const struct pwm_ops pxa_pwm_ops = {
119 .config = pxa_pwm_config,
120 .enable = pxa_pwm_enable,
121 .disable = pxa_pwm_disable,
122 .owner = THIS_MODULE,
123 };
124
125 #ifdef CONFIG_OF
126
127
128
129
130
131
132 static const struct of_device_id pwm_of_match[] = {
133 { .compatible = "marvell,pxa250-pwm", .data = &pwm_id_table[0]},
134 { .compatible = "marvell,pxa270-pwm", .data = &pwm_id_table[0]},
135 { .compatible = "marvell,pxa168-pwm", .data = &pwm_id_table[0]},
136 { .compatible = "marvell,pxa910-pwm", .data = &pwm_id_table[0]},
137 { }
138 };
139 MODULE_DEVICE_TABLE(of, pwm_of_match);
140 #else
141 #define pwm_of_match NULL
142 #endif
143
144 static const struct platform_device_id *pxa_pwm_get_id_dt(struct device *dev)
145 {
146 const struct of_device_id *id = of_match_device(pwm_of_match, dev);
147
148 return id ? id->data : NULL;
149 }
150
151 static struct pwm_device *
152 pxa_pwm_of_xlate(struct pwm_chip *pc, const struct of_phandle_args *args)
153 {
154 struct pwm_device *pwm;
155
156 pwm = pwm_request_from_chip(pc, 0, NULL);
157 if (IS_ERR(pwm))
158 return pwm;
159
160 pwm->args.period = args->args[0];
161
162 return pwm;
163 }
164
165 static int pwm_probe(struct platform_device *pdev)
166 {
167 const struct platform_device_id *id = platform_get_device_id(pdev);
168 struct pxa_pwm_chip *pwm;
169 struct resource *r;
170 int ret = 0;
171
172 if (IS_ENABLED(CONFIG_OF) && id == NULL)
173 id = pxa_pwm_get_id_dt(&pdev->dev);
174
175 if (id == NULL)
176 return -EINVAL;
177
178 pwm = devm_kzalloc(&pdev->dev, sizeof(*pwm), GFP_KERNEL);
179 if (pwm == NULL)
180 return -ENOMEM;
181
182 pwm->clk = devm_clk_get(&pdev->dev, NULL);
183 if (IS_ERR(pwm->clk))
184 return PTR_ERR(pwm->clk);
185
186 pwm->chip.dev = &pdev->dev;
187 pwm->chip.ops = &pxa_pwm_ops;
188 pwm->chip.base = -1;
189 pwm->chip.npwm = (id->driver_data & HAS_SECONDARY_PWM) ? 2 : 1;
190
191 if (IS_ENABLED(CONFIG_OF)) {
192 pwm->chip.of_xlate = pxa_pwm_of_xlate;
193 pwm->chip.of_pwm_n_cells = 1;
194 }
195
196 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
197 pwm->mmio_base = devm_ioremap_resource(&pdev->dev, r);
198 if (IS_ERR(pwm->mmio_base))
199 return PTR_ERR(pwm->mmio_base);
200
201 ret = pwmchip_add(&pwm->chip);
202 if (ret < 0) {
203 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
204 return ret;
205 }
206
207 platform_set_drvdata(pdev, pwm);
208 return 0;
209 }
210
211 static int pwm_remove(struct platform_device *pdev)
212 {
213 struct pxa_pwm_chip *chip;
214
215 chip = platform_get_drvdata(pdev);
216 if (chip == NULL)
217 return -ENODEV;
218
219 return pwmchip_remove(&chip->chip);
220 }
221
222 static struct platform_driver pwm_driver = {
223 .driver = {
224 .name = "pxa25x-pwm",
225 .of_match_table = pwm_of_match,
226 },
227 .probe = pwm_probe,
228 .remove = pwm_remove,
229 .id_table = pwm_id_table,
230 };
231
232 module_platform_driver(pwm_driver);
233
234 MODULE_LICENSE("GPL v2");