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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
25static 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};
33MODULE_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
43struct pxa_pwm_chip {
44 struct pwm_chip chip;
45 struct device *dev;
46
47 struct clk *clk;
48 void __iomem *mmio_base;
49};
50
51static 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
60static 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
104static 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
111static 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
118static 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
132static 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};
139MODULE_DEVICE_TABLE(of, pwm_of_match);
140#else
141#define pwm_of_match NULL
142#endif
143
144static 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
151static struct pwm_device *
152pxa_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
165static 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 *pc;
169 int ret = 0;
170
171 if (IS_ENABLED(CONFIG_OF) && id == NULL)
172 id = pxa_pwm_get_id_dt(&pdev->dev);
173
174 if (id == NULL)
175 return -EINVAL;
176
177 pc = devm_kzalloc(&pdev->dev, sizeof(*pc), GFP_KERNEL);
178 if (pc == NULL)
179 return -ENOMEM;
180
181 pc->clk = devm_clk_get(&pdev->dev, NULL);
182 if (IS_ERR(pc->clk))
183 return PTR_ERR(pc->clk);
184
185 pc->chip.dev = &pdev->dev;
186 pc->chip.ops = &pxa_pwm_ops;
187 pc->chip.npwm = (id->driver_data & HAS_SECONDARY_PWM) ? 2 : 1;
188
189 if (IS_ENABLED(CONFIG_OF)) {
190 pc->chip.of_xlate = pxa_pwm_of_xlate;
191 pc->chip.of_pwm_n_cells = 1;
192 }
193
194 pc->mmio_base = devm_platform_ioremap_resource(pdev, 0);
195 if (IS_ERR(pc->mmio_base))
196 return PTR_ERR(pc->mmio_base);
197
198 ret = devm_pwmchip_add(&pdev->dev, &pc->chip);
199 if (ret < 0) {
200 dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
201 return ret;
202 }
203
204 return 0;
205}
206
207static struct platform_driver pwm_driver = {
208 .driver = {
209 .name = "pxa25x-pwm",
210 .of_match_table = pwm_of_match,
211 },
212 .probe = pwm_probe,
213 .id_table = pwm_id_table,
214};
215
216module_platform_driver(pwm_driver);
217
218MODULE_LICENSE("GPL v2");
219