Loading...
1/*
2 * Copyright (C) ST-Ericsson SA 2010
3 *
4 * Author: Arun R Murthy <arun.murthy@stericsson.com>
5 * License terms: GNU General Public License (GPL) version 2
6 */
7#include <linux/err.h>
8#include <linux/platform_device.h>
9#include <linux/slab.h>
10#include <linux/pwm.h>
11#include <linux/mfd/abx500.h>
12#include <linux/mfd/abx500/ab8500.h>
13#include <linux/module.h>
14
15/*
16 * PWM Out generators
17 * Bank: 0x10
18 */
19#define AB8500_PWM_OUT_CTRL1_REG 0x60
20#define AB8500_PWM_OUT_CTRL2_REG 0x61
21#define AB8500_PWM_OUT_CTRL7_REG 0x66
22
23struct ab8500_pwm_chip {
24 struct pwm_chip chip;
25};
26
27static int ab8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
28 int duty_ns, int period_ns)
29{
30 int ret = 0;
31 unsigned int higher_val, lower_val;
32 u8 reg;
33
34 /*
35 * get the first 8 bits that are be written to
36 * AB8500_PWM_OUT_CTRL1_REG[0:7]
37 */
38 lower_val = duty_ns & 0x00FF;
39 /*
40 * get bits [9:10] that are to be written to
41 * AB8500_PWM_OUT_CTRL2_REG[0:1]
42 */
43 higher_val = ((duty_ns & 0x0300) >> 8);
44
45 reg = AB8500_PWM_OUT_CTRL1_REG + ((chip->base - 1) * 2);
46
47 ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
48 reg, (u8)lower_val);
49 if (ret < 0)
50 return ret;
51 ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
52 (reg + 1), (u8)higher_val);
53
54 return ret;
55}
56
57static int ab8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
58{
59 int ret;
60
61 ret = abx500_mask_and_set_register_interruptible(chip->dev,
62 AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
63 1 << (chip->base - 1), 1 << (chip->base - 1));
64 if (ret < 0)
65 dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n",
66 pwm->label, ret);
67 return ret;
68}
69
70static void ab8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
71{
72 int ret;
73
74 ret = abx500_mask_and_set_register_interruptible(chip->dev,
75 AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
76 1 << (chip->base - 1), 0);
77 if (ret < 0)
78 dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
79 pwm->label, ret);
80}
81
82static const struct pwm_ops ab8500_pwm_ops = {
83 .config = ab8500_pwm_config,
84 .enable = ab8500_pwm_enable,
85 .disable = ab8500_pwm_disable,
86 .owner = THIS_MODULE,
87};
88
89static int ab8500_pwm_probe(struct platform_device *pdev)
90{
91 struct ab8500_pwm_chip *ab8500;
92 int err;
93
94 /*
95 * Nothing to be done in probe, this is required to get the
96 * device which is required for ab8500 read and write
97 */
98 ab8500 = devm_kzalloc(&pdev->dev, sizeof(*ab8500), GFP_KERNEL);
99 if (ab8500 == NULL)
100 return -ENOMEM;
101
102 ab8500->chip.dev = &pdev->dev;
103 ab8500->chip.ops = &ab8500_pwm_ops;
104 ab8500->chip.base = pdev->id;
105 ab8500->chip.npwm = 1;
106
107 err = pwmchip_add(&ab8500->chip);
108 if (err < 0)
109 return err;
110
111 dev_dbg(&pdev->dev, "pwm probe successful\n");
112 platform_set_drvdata(pdev, ab8500);
113
114 return 0;
115}
116
117static int ab8500_pwm_remove(struct platform_device *pdev)
118{
119 struct ab8500_pwm_chip *ab8500 = platform_get_drvdata(pdev);
120 int err;
121
122 err = pwmchip_remove(&ab8500->chip);
123 if (err < 0)
124 return err;
125
126 dev_dbg(&pdev->dev, "pwm driver removed\n");
127
128 return 0;
129}
130
131static struct platform_driver ab8500_pwm_driver = {
132 .driver = {
133 .name = "ab8500-pwm",
134 },
135 .probe = ab8500_pwm_probe,
136 .remove = ab8500_pwm_remove,
137};
138module_platform_driver(ab8500_pwm_driver);
139
140MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>");
141MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
142MODULE_ALIAS("platform:ab8500-pwm");
143MODULE_LICENSE("GPL v2");
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (C) ST-Ericsson SA 2010
4 *
5 * Author: Arun R Murthy <arun.murthy@stericsson.com>
6 * Datasheet: https://web.archive.org/web/20130614115108/http://www.stericsson.com/developers/CD00291561_UM1031_AB8500_user_manual-rev5_CTDS_public.pdf
7 */
8#include <linux/err.h>
9#include <linux/platform_device.h>
10#include <linux/slab.h>
11#include <linux/pwm.h>
12#include <linux/mfd/abx500.h>
13#include <linux/mfd/abx500/ab8500.h>
14#include <linux/module.h>
15
16/*
17 * PWM Out generators
18 * Bank: 0x10
19 */
20#define AB8500_PWM_OUT_CTRL1_REG 0x60
21#define AB8500_PWM_OUT_CTRL2_REG 0x61
22#define AB8500_PWM_OUT_CTRL7_REG 0x66
23
24#define AB8500_PWM_CLKRATE 9600000
25
26struct ab8500_pwm_chip {
27 struct pwm_chip chip;
28 unsigned int hwid;
29};
30
31static struct ab8500_pwm_chip *ab8500_pwm_from_chip(struct pwm_chip *chip)
32{
33 return container_of(chip, struct ab8500_pwm_chip, chip);
34}
35
36static int ab8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
37 const struct pwm_state *state)
38{
39 int ret;
40 u8 reg;
41 u8 higher_val, lower_val;
42 unsigned int duty_steps, div;
43 struct ab8500_pwm_chip *ab8500 = ab8500_pwm_from_chip(chip);
44
45 if (state->polarity != PWM_POLARITY_NORMAL)
46 return -EINVAL;
47
48 if (state->enabled) {
49 /*
50 * A time quantum is
51 * q = (32 - FreqPWMOutx[3:0]) / AB8500_PWM_CLKRATE
52 * The period is always 1024 q, duty_cycle is between 1q and 1024q.
53 *
54 * FreqPWMOutx[3:0] | output frequency | output frequency | 1024q = period
55 * | (from manual) | (1 / 1024q) | = 1 / freq
56 * -----------------+------------------+------------------+--------------
57 * b0000 | 293 Hz | 292.968750 Hz | 3413333.33 ns
58 * b0001 | 302 Hz | 302.419355 Hz | 3306666.66 ns
59 * b0010 | 312 Hz | 312.500000 Hz | 3200000 ns
60 * b0011 | 323 Hz | 323.275862 Hz | 3093333.33 ns
61 * b0100 | 334 Hz | 334.821429 Hz | 2986666.66 ns
62 * b0101 | 347 Hz | 347.222222 Hz | 2880000 ns
63 * b0110 | 360 Hz | 360.576923 Hz | 2773333.33 ns
64 * b0111 | 375 Hz | 375.000000 Hz | 2666666.66 ns
65 * b1000 | 390 Hz | 390.625000 Hz | 2560000 ns
66 * b1001 | 407 Hz | 407.608696 Hz | 2453333.33 ns
67 * b1010 | 426 Hz | 426.136364 Hz | 2346666.66 ns
68 * b1011 | 446 Hz | 446.428571 Hz | 2240000 ns
69 * b1100 | 468 Hz | 468.750000 Hz | 2133333.33 ns
70 * b1101 | 493 Hz | 493.421053 Hz | 2026666.66 ns
71 * b1110 | 520 Hz | 520.833333 Hz | 1920000 ns
72 * b1111 | 551 Hz | 551.470588 Hz | 1813333.33 ns
73 *
74 *
75 * AB8500_PWM_CLKRATE is a multiple of 1024, so the division by
76 * 1024 can be done in this factor without loss of precision.
77 */
78 div = min_t(u64, mul_u64_u64_div_u64(state->period,
79 AB8500_PWM_CLKRATE >> 10,
80 NSEC_PER_SEC), 32); /* 32 - FreqPWMOutx[3:0] */
81 if (div <= 16)
82 /* requested period < 3413333.33 */
83 return -EINVAL;
84
85 duty_steps = max_t(u64, mul_u64_u64_div_u64(state->duty_cycle,
86 AB8500_PWM_CLKRATE,
87 (u64)NSEC_PER_SEC * div), 1024);
88 }
89
90 /*
91 * The hardware doesn't support duty_steps = 0 explicitly, but emits low
92 * when disabled.
93 */
94 if (!state->enabled || duty_steps == 0) {
95 ret = abx500_mask_and_set_register_interruptible(chip->dev,
96 AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
97 1 << ab8500->hwid, 0);
98
99 if (ret < 0)
100 dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
101 pwm->label, ret);
102 return ret;
103 }
104
105 /*
106 * The lower 8 bits of duty_steps is written to ...
107 * AB8500_PWM_OUT_CTRL1_REG[0:7]
108 */
109 lower_val = (duty_steps - 1) & 0x00ff;
110 /*
111 * The two remaining high bits to
112 * AB8500_PWM_OUT_CTRL2_REG[0:1]; together with FreqPWMOutx.
113 */
114 higher_val = ((duty_steps - 1) & 0x0300) >> 8 | (32 - div) << 4;
115
116 reg = AB8500_PWM_OUT_CTRL1_REG + (ab8500->hwid * 2);
117
118 ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
119 reg, lower_val);
120 if (ret < 0)
121 return ret;
122
123 ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
124 (reg + 1), higher_val);
125 if (ret < 0)
126 return ret;
127
128 /* enable */
129 ret = abx500_mask_and_set_register_interruptible(chip->dev,
130 AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
131 1 << ab8500->hwid, 1 << ab8500->hwid);
132 if (ret < 0)
133 dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n",
134 pwm->label, ret);
135
136 return ret;
137}
138
139static int ab8500_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
140 struct pwm_state *state)
141{
142 u8 ctrl7, lower_val, higher_val;
143 int ret;
144 struct ab8500_pwm_chip *ab8500 = ab8500_pwm_from_chip(chip);
145 unsigned int div, duty_steps;
146
147 ret = abx500_get_register_interruptible(chip->dev, AB8500_MISC,
148 AB8500_PWM_OUT_CTRL7_REG,
149 &ctrl7);
150 if (ret)
151 return ret;
152
153 state->polarity = PWM_POLARITY_NORMAL;
154
155 if (!(ctrl7 & 1 << ab8500->hwid)) {
156 state->enabled = false;
157 return 0;
158 }
159
160 ret = abx500_get_register_interruptible(chip->dev, AB8500_MISC,
161 AB8500_PWM_OUT_CTRL1_REG + (ab8500->hwid * 2),
162 &lower_val);
163 if (ret)
164 return ret;
165
166 ret = abx500_get_register_interruptible(chip->dev, AB8500_MISC,
167 AB8500_PWM_OUT_CTRL2_REG + (ab8500->hwid * 2),
168 &higher_val);
169 if (ret)
170 return ret;
171
172 div = 32 - ((higher_val & 0xf0) >> 4);
173 duty_steps = ((higher_val & 3) << 8 | lower_val) + 1;
174
175 state->period = DIV64_U64_ROUND_UP((u64)div << 10, AB8500_PWM_CLKRATE);
176 state->duty_cycle = DIV64_U64_ROUND_UP((u64)div * duty_steps, AB8500_PWM_CLKRATE);
177
178 return 0;
179}
180
181static const struct pwm_ops ab8500_pwm_ops = {
182 .apply = ab8500_pwm_apply,
183 .get_state = ab8500_pwm_get_state,
184};
185
186static int ab8500_pwm_probe(struct platform_device *pdev)
187{
188 struct ab8500_pwm_chip *ab8500;
189 int err;
190
191 if (pdev->id < 1 || pdev->id > 31)
192 return dev_err_probe(&pdev->dev, -EINVAL, "Invalid device id %d\n", pdev->id);
193
194 /*
195 * Nothing to be done in probe, this is required to get the
196 * device which is required for ab8500 read and write
197 */
198 ab8500 = devm_kzalloc(&pdev->dev, sizeof(*ab8500), GFP_KERNEL);
199 if (ab8500 == NULL)
200 return -ENOMEM;
201
202 ab8500->chip.dev = &pdev->dev;
203 ab8500->chip.ops = &ab8500_pwm_ops;
204 ab8500->chip.npwm = 1;
205 ab8500->hwid = pdev->id - 1;
206
207 err = devm_pwmchip_add(&pdev->dev, &ab8500->chip);
208 if (err < 0)
209 return dev_err_probe(&pdev->dev, err, "Failed to add pwm chip\n");
210
211 dev_dbg(&pdev->dev, "pwm probe successful\n");
212
213 return 0;
214}
215
216static struct platform_driver ab8500_pwm_driver = {
217 .driver = {
218 .name = "ab8500-pwm",
219 },
220 .probe = ab8500_pwm_probe,
221};
222module_platform_driver(ab8500_pwm_driver);
223
224MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>");
225MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
226MODULE_ALIAS("platform:ab8500-pwm");
227MODULE_LICENSE("GPL v2");