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 */
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
23 struct ab8500_pwm_chip {
24 struct pwm_chip chip;
25 unsigned int hwid;
26 };
27
ab8500_pwm_from_chip(struct pwm_chip * chip)28 static struct ab8500_pwm_chip *ab8500_pwm_from_chip(struct pwm_chip *chip)
29 {
30 return container_of(chip, struct ab8500_pwm_chip, chip);
31 }
32
ab8500_pwm_apply(struct pwm_chip * chip,struct pwm_device * pwm,const struct pwm_state * state)33 static int ab8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
34 const struct pwm_state *state)
35 {
36 int ret;
37 u8 reg;
38 unsigned int higher_val, lower_val;
39 struct ab8500_pwm_chip *ab8500 = ab8500_pwm_from_chip(chip);
40
41 if (state->polarity != PWM_POLARITY_NORMAL)
42 return -EINVAL;
43
44 if (!state->enabled) {
45 ret = abx500_mask_and_set_register_interruptible(chip->dev,
46 AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
47 1 << ab8500->hwid, 0);
48
49 if (ret < 0)
50 dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
51 pwm->label, ret);
52 return ret;
53 }
54
55 /*
56 * get the first 8 bits that are be written to
57 * AB8500_PWM_OUT_CTRL1_REG[0:7]
58 */
59 lower_val = state->duty_cycle & 0x00FF;
60 /*
61 * get bits [9:10] that are to be written to
62 * AB8500_PWM_OUT_CTRL2_REG[0:1]
63 */
64 higher_val = ((state->duty_cycle & 0x0300) >> 8);
65
66 reg = AB8500_PWM_OUT_CTRL1_REG + (ab8500->hwid * 2);
67
68 ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
69 reg, (u8)lower_val);
70 if (ret < 0)
71 return ret;
72
73 ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
74 (reg + 1), (u8)higher_val);
75 if (ret < 0)
76 return ret;
77
78 ret = abx500_mask_and_set_register_interruptible(chip->dev,
79 AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
80 1 << ab8500->hwid, 1 << ab8500->hwid);
81 if (ret < 0)
82 dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n",
83 pwm->label, ret);
84
85 return ret;
86 }
87
88 static const struct pwm_ops ab8500_pwm_ops = {
89 .apply = ab8500_pwm_apply,
90 .owner = THIS_MODULE,
91 };
92
ab8500_pwm_probe(struct platform_device * pdev)93 static int ab8500_pwm_probe(struct platform_device *pdev)
94 {
95 struct ab8500_pwm_chip *ab8500;
96 int err;
97
98 if (pdev->id < 1 || pdev->id > 31)
99 return dev_err_probe(&pdev->dev, EINVAL, "Invalid device id %d\n", pdev->id);
100
101 /*
102 * Nothing to be done in probe, this is required to get the
103 * device which is required for ab8500 read and write
104 */
105 ab8500 = devm_kzalloc(&pdev->dev, sizeof(*ab8500), GFP_KERNEL);
106 if (ab8500 == NULL)
107 return -ENOMEM;
108
109 ab8500->chip.dev = &pdev->dev;
110 ab8500->chip.ops = &ab8500_pwm_ops;
111 ab8500->chip.npwm = 1;
112 ab8500->hwid = pdev->id - 1;
113
114 err = devm_pwmchip_add(&pdev->dev, &ab8500->chip);
115 if (err < 0)
116 return dev_err_probe(&pdev->dev, err, "Failed to add pwm chip\n");
117
118 dev_dbg(&pdev->dev, "pwm probe successful\n");
119
120 return 0;
121 }
122
123 static struct platform_driver ab8500_pwm_driver = {
124 .driver = {
125 .name = "ab8500-pwm",
126 },
127 .probe = ab8500_pwm_probe,
128 };
129 module_platform_driver(ab8500_pwm_driver);
130
131 MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>");
132 MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
133 MODULE_ALIAS("platform:ab8500-pwm");
134 MODULE_LICENSE("GPL v2");
135