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14#include <linux/clk.h>
15#include <linux/delay.h>
16#include <linux/err.h>
17#include <linux/io.h>
18#include <linux/math64.h>
19#include <linux/module.h>
20#include <linux/of.h>
21#include <linux/platform_device.h>
22#include <linux/pwm.h>
23
24#define IPROC_PWM_CTRL_OFFSET 0x00
25#define IPROC_PWM_CTRL_TYPE_SHIFT(ch) (15 + (ch))
26#define IPROC_PWM_CTRL_POLARITY_SHIFT(ch) (8 + (ch))
27#define IPROC_PWM_CTRL_EN_SHIFT(ch) (ch)
28
29#define IPROC_PWM_PERIOD_OFFSET(ch) (0x04 + ((ch) << 3))
30#define IPROC_PWM_PERIOD_MIN 0x02
31#define IPROC_PWM_PERIOD_MAX 0xffff
32
33#define IPROC_PWM_DUTY_CYCLE_OFFSET(ch) (0x08 + ((ch) << 3))
34#define IPROC_PWM_DUTY_CYCLE_MIN 0x00
35#define IPROC_PWM_DUTY_CYCLE_MAX 0xffff
36
37#define IPROC_PWM_PRESCALE_OFFSET 0x24
38#define IPROC_PWM_PRESCALE_BITS 0x06
39#define IPROC_PWM_PRESCALE_SHIFT(ch) ((3 - (ch)) * \
40 IPROC_PWM_PRESCALE_BITS)
41#define IPROC_PWM_PRESCALE_MASK(ch) (IPROC_PWM_PRESCALE_MAX << \
42 IPROC_PWM_PRESCALE_SHIFT(ch))
43#define IPROC_PWM_PRESCALE_MIN 0x00
44#define IPROC_PWM_PRESCALE_MAX 0x3f
45
46struct iproc_pwmc {
47 struct pwm_chip chip;
48 void __iomem *base;
49 struct clk *clk;
50};
51
52static inline struct iproc_pwmc *to_iproc_pwmc(struct pwm_chip *chip)
53{
54 return container_of(chip, struct iproc_pwmc, chip);
55}
56
57static void iproc_pwmc_enable(struct iproc_pwmc *ip, unsigned int channel)
58{
59 u32 value;
60
61 value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
62 value |= 1 << IPROC_PWM_CTRL_EN_SHIFT(channel);
63 writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
64
65
66 ndelay(400);
67}
68
69static void iproc_pwmc_disable(struct iproc_pwmc *ip, unsigned int channel)
70{
71 u32 value;
72
73 value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
74 value &= ~(1 << IPROC_PWM_CTRL_EN_SHIFT(channel));
75 writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
76
77
78 ndelay(400);
79}
80
81static void iproc_pwmc_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
82 struct pwm_state *state)
83{
84 struct iproc_pwmc *ip = to_iproc_pwmc(chip);
85 u64 tmp, multi, rate;
86 u32 value, prescale;
87
88 value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
89
90 if (value & BIT(IPROC_PWM_CTRL_EN_SHIFT(pwm->hwpwm)))
91 state->enabled = true;
92 else
93 state->enabled = false;
94
95 if (value & BIT(IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm)))
96 state->polarity = PWM_POLARITY_NORMAL;
97 else
98 state->polarity = PWM_POLARITY_INVERSED;
99
100 rate = clk_get_rate(ip->clk);
101 if (rate == 0) {
102 state->period = 0;
103 state->duty_cycle = 0;
104 return;
105 }
106
107 value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET);
108 prescale = value >> IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm);
109 prescale &= IPROC_PWM_PRESCALE_MAX;
110
111 multi = NSEC_PER_SEC * (prescale + 1);
112
113 value = readl(ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm));
114 tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
115 state->period = div64_u64(tmp, rate);
116
117 value = readl(ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm));
118 tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
119 state->duty_cycle = div64_u64(tmp, rate);
120}
121
122static int iproc_pwmc_apply(struct pwm_chip *chip, struct pwm_device *pwm,
123 const struct pwm_state *state)
124{
125 unsigned long prescale = IPROC_PWM_PRESCALE_MIN;
126 struct iproc_pwmc *ip = to_iproc_pwmc(chip);
127 u32 value, period, duty;
128 u64 rate;
129
130 rate = clk_get_rate(ip->clk);
131
132
133
134
135
136
137
138
139
140
141
142 while (1) {
143 u64 value, div;
144
145 div = NSEC_PER_SEC * (prescale + 1);
146 value = rate * state->period;
147 period = div64_u64(value, div);
148 value = rate * state->duty_cycle;
149 duty = div64_u64(value, div);
150
151 if (period < IPROC_PWM_PERIOD_MIN)
152 return -EINVAL;
153
154 if (period <= IPROC_PWM_PERIOD_MAX &&
155 duty <= IPROC_PWM_DUTY_CYCLE_MAX)
156 break;
157
158
159 if (++prescale > IPROC_PWM_PRESCALE_MAX)
160 return -EINVAL;
161 }
162
163 iproc_pwmc_disable(ip, pwm->hwpwm);
164
165
166 value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET);
167 value &= ~IPROC_PWM_PRESCALE_MASK(pwm->hwpwm);
168 value |= prescale << IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm);
169 writel(value, ip->base + IPROC_PWM_PRESCALE_OFFSET);
170
171
172 writel(period, ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm));
173 writel(duty, ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm));
174
175
176 value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
177
178 if (state->polarity == PWM_POLARITY_NORMAL)
179 value |= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm);
180 else
181 value &= ~(1 << IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm));
182
183 writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
184
185 if (state->enabled)
186 iproc_pwmc_enable(ip, pwm->hwpwm);
187
188 return 0;
189}
190
191static const struct pwm_ops iproc_pwm_ops = {
192 .apply = iproc_pwmc_apply,
193 .get_state = iproc_pwmc_get_state,
194 .owner = THIS_MODULE,
195};
196
197static int iproc_pwmc_probe(struct platform_device *pdev)
198{
199 struct iproc_pwmc *ip;
200 struct resource *res;
201 unsigned int i;
202 u32 value;
203 int ret;
204
205 ip = devm_kzalloc(&pdev->dev, sizeof(*ip), GFP_KERNEL);
206 if (!ip)
207 return -ENOMEM;
208
209 platform_set_drvdata(pdev, ip);
210
211 ip->chip.dev = &pdev->dev;
212 ip->chip.ops = &iproc_pwm_ops;
213 ip->chip.base = -1;
214 ip->chip.npwm = 4;
215 ip->chip.of_xlate = of_pwm_xlate_with_flags;
216 ip->chip.of_pwm_n_cells = 3;
217
218 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
219 ip->base = devm_ioremap_resource(&pdev->dev, res);
220 if (IS_ERR(ip->base))
221 return PTR_ERR(ip->base);
222
223 ip->clk = devm_clk_get(&pdev->dev, NULL);
224 if (IS_ERR(ip->clk)) {
225 dev_err(&pdev->dev, "failed to get clock: %ld\n",
226 PTR_ERR(ip->clk));
227 return PTR_ERR(ip->clk);
228 }
229
230 ret = clk_prepare_enable(ip->clk);
231 if (ret < 0) {
232 dev_err(&pdev->dev, "failed to enable clock: %d\n", ret);
233 return ret;
234 }
235
236
237 value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
238
239 for (i = 0; i < ip->chip.npwm; i++) {
240 value &= ~(1 << IPROC_PWM_CTRL_TYPE_SHIFT(i));
241 value |= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(i);
242 }
243
244 writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
245
246 ret = pwmchip_add(&ip->chip);
247 if (ret < 0) {
248 dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
249 clk_disable_unprepare(ip->clk);
250 }
251
252 return ret;
253}
254
255static int iproc_pwmc_remove(struct platform_device *pdev)
256{
257 struct iproc_pwmc *ip = platform_get_drvdata(pdev);
258
259 clk_disable_unprepare(ip->clk);
260
261 return pwmchip_remove(&ip->chip);
262}
263
264static const struct of_device_id bcm_iproc_pwmc_dt[] = {
265 { .compatible = "brcm,iproc-pwm" },
266 { },
267};
268MODULE_DEVICE_TABLE(of, bcm_iproc_pwmc_dt);
269
270static struct platform_driver iproc_pwmc_driver = {
271 .driver = {
272 .name = "bcm-iproc-pwm",
273 .of_match_table = bcm_iproc_pwmc_dt,
274 },
275 .probe = iproc_pwmc_probe,
276 .remove = iproc_pwmc_remove,
277};
278module_platform_driver(iproc_pwmc_driver);
279
280MODULE_AUTHOR("Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>");
281MODULE_DESCRIPTION("Broadcom iProc PWM driver");
282MODULE_LICENSE("GPL v2");
283
