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1/*
2 * Copyright (C) 2016 Broadcom
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation version 2.
7 *
8 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
9 * kind, whether express or implied; without even the implied warranty
10 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
11 * GNU General Public License for more details.
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 /* must be a 400 ns delay between clearing and setting enable bit */
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 /* must be a 400 ns delay between clearing and setting enable bit */
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 * Find period count, duty count and prescale to suit duty_cycle and
129 * period. This is done according to formulas described below:
130 *
131 * period_ns = 10^9 * (PRESCALE + 1) * PC / PWM_CLK_RATE
132 * duty_ns = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
133 *
134 * PC = (PWM_CLK_RATE * period_ns) / (10^9 * (PRESCALE + 1))
135 * DC = (PWM_CLK_RATE * duty_ns) / (10^9 * (PRESCALE + 1))
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 /* Otherwise, increase prescale and recalculate counts */
155 if (++prescale > IPROC_PWM_PRESCALE_MAX)
156 return -EINVAL;
157 }
158
159 iproc_pwmc_disable(ip, pwm->hwpwm);
160
161 /* Set prescale */
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 /* set period and duty cycle */
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 /* set polarity */
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 /* Set full drive and normal polarity for all channels */
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");
1// SPDX-License-Identifier: GPL-2.0-only
2// Copyright (C) 2016 Broadcom
3
4#include <linux/clk.h>
5#include <linux/delay.h>
6#include <linux/err.h>
7#include <linux/io.h>
8#include <linux/math64.h>
9#include <linux/module.h>
10#include <linux/of.h>
11#include <linux/platform_device.h>
12#include <linux/pwm.h>
13
14#define IPROC_PWM_CTRL_OFFSET 0x00
15#define IPROC_PWM_CTRL_TYPE_SHIFT(ch) (15 + (ch))
16#define IPROC_PWM_CTRL_POLARITY_SHIFT(ch) (8 + (ch))
17#define IPROC_PWM_CTRL_EN_SHIFT(ch) (ch)
18
19#define IPROC_PWM_PERIOD_OFFSET(ch) (0x04 + ((ch) << 3))
20#define IPROC_PWM_PERIOD_MIN 0x02
21#define IPROC_PWM_PERIOD_MAX 0xffff
22
23#define IPROC_PWM_DUTY_CYCLE_OFFSET(ch) (0x08 + ((ch) << 3))
24#define IPROC_PWM_DUTY_CYCLE_MIN 0x00
25#define IPROC_PWM_DUTY_CYCLE_MAX 0xffff
26
27#define IPROC_PWM_PRESCALE_OFFSET 0x24
28#define IPROC_PWM_PRESCALE_BITS 0x06
29#define IPROC_PWM_PRESCALE_SHIFT(ch) ((3 - (ch)) * \
30 IPROC_PWM_PRESCALE_BITS)
31#define IPROC_PWM_PRESCALE_MASK(ch) (IPROC_PWM_PRESCALE_MAX << \
32 IPROC_PWM_PRESCALE_SHIFT(ch))
33#define IPROC_PWM_PRESCALE_MIN 0x00
34#define IPROC_PWM_PRESCALE_MAX 0x3f
35
36struct iproc_pwmc {
37 void __iomem *base;
38 struct clk *clk;
39};
40
41static inline struct iproc_pwmc *to_iproc_pwmc(struct pwm_chip *chip)
42{
43 return pwmchip_get_drvdata(chip);
44}
45
46static void iproc_pwmc_enable(struct iproc_pwmc *ip, unsigned int channel)
47{
48 u32 value;
49
50 value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
51 value |= 1 << IPROC_PWM_CTRL_EN_SHIFT(channel);
52 writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
53
54 /* must be a 400 ns delay between clearing and setting enable bit */
55 ndelay(400);
56}
57
58static void iproc_pwmc_disable(struct iproc_pwmc *ip, unsigned int channel)
59{
60 u32 value;
61
62 value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
63 value &= ~(1 << IPROC_PWM_CTRL_EN_SHIFT(channel));
64 writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
65
66 /* must be a 400 ns delay between clearing and setting enable bit */
67 ndelay(400);
68}
69
70static int iproc_pwmc_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
71 struct pwm_state *state)
72{
73 struct iproc_pwmc *ip = to_iproc_pwmc(chip);
74 u64 tmp, multi, rate;
75 u32 value, prescale;
76
77 value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
78
79 if (value & BIT(IPROC_PWM_CTRL_EN_SHIFT(pwm->hwpwm)))
80 state->enabled = true;
81 else
82 state->enabled = false;
83
84 if (value & BIT(IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm)))
85 state->polarity = PWM_POLARITY_NORMAL;
86 else
87 state->polarity = PWM_POLARITY_INVERSED;
88
89 rate = clk_get_rate(ip->clk);
90 if (rate == 0) {
91 state->period = 0;
92 state->duty_cycle = 0;
93 return 0;
94 }
95
96 value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET);
97 prescale = value >> IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm);
98 prescale &= IPROC_PWM_PRESCALE_MAX;
99
100 multi = NSEC_PER_SEC * (prescale + 1);
101
102 value = readl(ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm));
103 tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
104 state->period = div64_u64(tmp, rate);
105
106 value = readl(ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm));
107 tmp = (value & IPROC_PWM_PERIOD_MAX) * multi;
108 state->duty_cycle = div64_u64(tmp, rate);
109
110 return 0;
111}
112
113static int iproc_pwmc_apply(struct pwm_chip *chip, struct pwm_device *pwm,
114 const struct pwm_state *state)
115{
116 unsigned long prescale = IPROC_PWM_PRESCALE_MIN;
117 struct iproc_pwmc *ip = to_iproc_pwmc(chip);
118 u32 value, period, duty;
119 u64 rate;
120
121 rate = clk_get_rate(ip->clk);
122
123 /*
124 * Find period count, duty count and prescale to suit duty_cycle and
125 * period. This is done according to formulas described below:
126 *
127 * period_ns = 10^9 * (PRESCALE + 1) * PC / PWM_CLK_RATE
128 * duty_ns = 10^9 * (PRESCALE + 1) * DC / PWM_CLK_RATE
129 *
130 * PC = (PWM_CLK_RATE * period_ns) / (10^9 * (PRESCALE + 1))
131 * DC = (PWM_CLK_RATE * duty_ns) / (10^9 * (PRESCALE + 1))
132 */
133 while (1) {
134 u64 value, div;
135
136 div = NSEC_PER_SEC * (prescale + 1);
137 value = rate * state->period;
138 period = div64_u64(value, div);
139 value = rate * state->duty_cycle;
140 duty = div64_u64(value, div);
141
142 if (period < IPROC_PWM_PERIOD_MIN)
143 return -EINVAL;
144
145 if (period <= IPROC_PWM_PERIOD_MAX &&
146 duty <= IPROC_PWM_DUTY_CYCLE_MAX)
147 break;
148
149 /* Otherwise, increase prescale and recalculate counts */
150 if (++prescale > IPROC_PWM_PRESCALE_MAX)
151 return -EINVAL;
152 }
153
154 iproc_pwmc_disable(ip, pwm->hwpwm);
155
156 /* Set prescale */
157 value = readl(ip->base + IPROC_PWM_PRESCALE_OFFSET);
158 value &= ~IPROC_PWM_PRESCALE_MASK(pwm->hwpwm);
159 value |= prescale << IPROC_PWM_PRESCALE_SHIFT(pwm->hwpwm);
160 writel(value, ip->base + IPROC_PWM_PRESCALE_OFFSET);
161
162 /* set period and duty cycle */
163 writel(period, ip->base + IPROC_PWM_PERIOD_OFFSET(pwm->hwpwm));
164 writel(duty, ip->base + IPROC_PWM_DUTY_CYCLE_OFFSET(pwm->hwpwm));
165
166 /* set polarity */
167 value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
168
169 if (state->polarity == PWM_POLARITY_NORMAL)
170 value |= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm);
171 else
172 value &= ~(1 << IPROC_PWM_CTRL_POLARITY_SHIFT(pwm->hwpwm));
173
174 writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
175
176 if (state->enabled)
177 iproc_pwmc_enable(ip, pwm->hwpwm);
178
179 return 0;
180}
181
182static const struct pwm_ops iproc_pwm_ops = {
183 .apply = iproc_pwmc_apply,
184 .get_state = iproc_pwmc_get_state,
185};
186
187static int iproc_pwmc_probe(struct platform_device *pdev)
188{
189 struct pwm_chip *chip;
190 struct iproc_pwmc *ip;
191 unsigned int i;
192 u32 value;
193 int ret;
194
195 chip = devm_pwmchip_alloc(&pdev->dev, 4, sizeof(*ip));
196 if (IS_ERR(chip))
197 return PTR_ERR(chip);
198 ip = to_iproc_pwmc(chip);
199
200 platform_set_drvdata(pdev, ip);
201
202 chip->ops = &iproc_pwm_ops;
203
204 ip->base = devm_platform_ioremap_resource(pdev, 0);
205 if (IS_ERR(ip->base))
206 return PTR_ERR(ip->base);
207
208 ip->clk = devm_clk_get_enabled(&pdev->dev, NULL);
209 if (IS_ERR(ip->clk))
210 return dev_err_probe(&pdev->dev, PTR_ERR(ip->clk),
211 "failed to get clock\n");
212
213 /* Set full drive and normal polarity for all channels */
214 value = readl(ip->base + IPROC_PWM_CTRL_OFFSET);
215
216 for (i = 0; i < chip->npwm; i++) {
217 value &= ~(1 << IPROC_PWM_CTRL_TYPE_SHIFT(i));
218 value |= 1 << IPROC_PWM_CTRL_POLARITY_SHIFT(i);
219 }
220
221 writel(value, ip->base + IPROC_PWM_CTRL_OFFSET);
222
223 ret = devm_pwmchip_add(&pdev->dev, chip);
224 if (ret < 0)
225 return dev_err_probe(&pdev->dev, ret,
226 "failed to add PWM chip\n");
227
228 return 0;
229}
230
231static const struct of_device_id bcm_iproc_pwmc_dt[] = {
232 { .compatible = "brcm,iproc-pwm" },
233 { },
234};
235MODULE_DEVICE_TABLE(of, bcm_iproc_pwmc_dt);
236
237static struct platform_driver iproc_pwmc_driver = {
238 .driver = {
239 .name = "bcm-iproc-pwm",
240 .of_match_table = bcm_iproc_pwmc_dt,
241 },
242 .probe = iproc_pwmc_probe,
243};
244module_platform_driver(iproc_pwmc_driver);
245
246MODULE_AUTHOR("Yendapally Reddy Dhananjaya Reddy <yendapally.reddy@broadcom.com>");
247MODULE_DESCRIPTION("Broadcom iProc PWM driver");
248MODULE_LICENSE("GPL v2");