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
 23struct ab8500_pwm_chip {
 24	struct pwm_chip chip;
 25	unsigned int hwid;
 26};
 27
 28static 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
 33static 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
 88static const struct pwm_ops ab8500_pwm_ops = {
 89	.apply = ab8500_pwm_apply,
 90	.owner = THIS_MODULE,
 91};
 92
 93static 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
123static struct platform_driver ab8500_pwm_driver = {
124	.driver = {
125		.name = "ab8500-pwm",
126	},
127	.probe = ab8500_pwm_probe,
128};
129module_platform_driver(ab8500_pwm_driver);
130
131MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>");
132MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
133MODULE_ALIAS("platform:ab8500-pwm");
134MODULE_LICENSE("GPL v2");