1
2
3
4
5
6
7
8
9
10
11
12
13
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 rate = clk_get_rate(ip->clk);
89
90 value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
91
92 if (value & BIT(IPROC_PWM_CTRL_EN_SHIFT(pwm->hwpwm)))
93 state->enabled = true;
94 else
95 state->enabled = false;
96
97 if (value & BIT(IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm)))
98 state->polarity = PWM_POLARITY_NORMAL;
99 else
100 state->polarity = PWM_POLARITY_INVERSED;
101
102 value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET);
103 prescale = value >> IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm);
104 prescale &= IPROC_PWM_PRESCALE_MAX;
105
106 multi = NSEC_PER_SEC * (prescale + 1);
107
108 value = readl(ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm));
109 tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
110 state->period = div64_u64(tmp, rate);
111
112 value = readl(ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm));
113 tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
114 state->duty_cycle = div64_u64(tmp, rate);
115}
116
117static int iproc_pwmc_apply(struct pwm_chip *chip, struct pwm_device *pwm,
118 struct pwm_state *state)
119{
120 unsigned long prescale = IPROC_PWM_PRESCALE_MIN;
121 struct iproc_pwmc *ip = to_iproc_pwmc(chip);
122 u32 value, period, duty;
123 u64 rate;
124
125 rate = clk_get_rate(ip->clk);
126
127
128
129
130
131
132
133
134
135
136
137 while (1) {
138 u64 value, div;
139
140 div = NSEC_PER_SEC * (prescale + 1);
141 value = rate * state->period;
142 period = div64_u64(value, div);
143 value = rate * state->duty_cycle;
144 duty = div64_u64(value, div);
145
146 if (period < IPROC_PWM_PERIOD_MIN ||
147 duty < IPROC_PWM_DUTY_CYCLE_MIN)
148 return -EINVAL;
149
150 if (period <= IPROC_PWM_PERIOD_MAX &&
151 duty <= IPROC_PWM_DUTY_CYCLE_MAX)
152 break;
153
154
155 if (++prescale > IPROC_PWM_PRESCALE_MAX)
156 return -EINVAL;
157 }
158
159 iproc_pwmc_disable(ip, pwm->hwpwm);
160
161
162 value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET);
163 value &= ~IPROC_PWM_PRESCALE_MASK(pwm->hwpwm);
164 value |= prescale << IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm);
165 writel(value, ip->base + IPROC_PWM_PRESCALE_OFFSET);
166
167
168 writel(period, ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm));
169 writel(duty, ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm));
170
171
172 value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
173
174 if (state->polarity == PWM_POLARITY_NORMAL)
175 value |= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm);
176 else
177 value &= ~(1 << IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm));
178
179 writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
180
181 if (state->enabled)
182 iproc_pwmc_enable(ip, pwm->hwpwm);
183
184 return 0;
185}
186
187static const struct pwm_ops iproc_pwm_ops = {
188 .apply = iproc_pwmc_apply,
189 .get_state = iproc_pwmc_get_state,
190};
191
192static int iproc_pwmc_probe(struct platform_device *pdev)
193{
194 struct iproc_pwmc *ip;
195 struct resource *res;
196 unsigned int i;
197 u32 value;
198 int ret;
199
200 ip = devm_kzalloc(&pdev->dev, sizeof(*ip), GFP_KERNEL);
201 if (!ip)
202 return -ENOMEM;
203
204 platform_set_drvdata(pdev, ip);
205
206 ip->chip.dev = &pdev->dev;
207 ip->chip.ops = &iproc_pwm_ops;
208 ip->chip.base = -1;
209 ip->chip.npwm = 4;
210 ip->chip.of_xlate = of_pwm_xlate_with_flags;
211 ip->chip.of_pwm_n_cells = 3;
212
213 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
214 ip->base = devm_ioremap_resource(&pdev->dev, res);
215 if (IS_ERR(ip->base))
216 return PTR_ERR(ip->base);
217
218 ip->clk = devm_clk_get(&pdev->dev, NULL);
219 if (IS_ERR(ip->clk)) {
220 dev_err(&pdev->dev, "failed to get clock: %ld\n",
221 PTR_ERR(ip->clk));
222 return PTR_ERR(ip->clk);
223 }
224
225 ret = clk_prepare_enable(ip->clk);
226 if (ret < 0) {
227 dev_err(&pdev->dev, "failed to enable clock: %d\n", ret);
228 return ret;
229 }
230
231
232 value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
233
234 for (i = 0; i < ip->chip.npwm; i++) {
235 value &= ~(1 << IPROC_PWM_CTRL_TYPE_SHIFT(i));
236 value |= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(i);
237 }
238
239 writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
240
241 ret = pwmchip_add(&ip->chip);
242 if (ret < 0) {
243 dev_err(&pdev->dev, "failed to add PWM chip: %d\n", ret);
244 clk_disable_unprepare(ip->clk);
245 }
246
247 return ret;
248}
249
250static int iproc_pwmc_remove(struct platform_device *pdev)
251{
252 struct iproc_pwmc *ip = platform_get_drvdata(pdev);
253
254 clk_disable_unprepare(ip->clk);
255
256 return pwmchip_remove(&ip->chip);
257}
258
259static const struct of_device_id bcm_iproc_pwmc_dt[] = {
260 { .compatible = "brcm,iproc-pwm" },
261 { },
262};
263MODULE_DEVICE_TABLE(of, bcm_iproc_pwmc_dt);
264
265static struct platform_driver iproc_pwmc_driver = {
266 .driver = {
267 .name = "bcm-iproc-pwm",
268 .of_match_table = bcm_iproc_pwmc_dt,
269 },
270 .probe = iproc_pwmc_probe,
271 .remove = iproc_pwmc_remove,
272};
273module_platform_driver(iproc_pwmc_driver);
274
275MODULE_AUTHOR("Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>");
276MODULE_DESCRIPTION("Broadcom iProc PWM driver");
277MODULE_LICENSE("GPL v2");
278
