LXR linux/drivers/pwm/pwm-ab8500.c

   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");
 135