135 строки
3.3 KiB
C
135 строки
3.3 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) ST-Ericsson SA 2010
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*
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* Author: Arun R Murthy <arun.murthy@stericsson.com>
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*/
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#include <linux/err.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/pwm.h>
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#include <linux/mfd/abx500.h>
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#include <linux/mfd/abx500/ab8500.h>
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#include <linux/module.h>
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/*
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* PWM Out generators
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* Bank: 0x10
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*/
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#define AB8500_PWM_OUT_CTRL1_REG 0x60
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#define AB8500_PWM_OUT_CTRL2_REG 0x61
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#define AB8500_PWM_OUT_CTRL7_REG 0x66
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struct ab8500_pwm_chip {
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struct pwm_chip chip;
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unsigned int hwid;
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};
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static struct ab8500_pwm_chip *ab8500_pwm_from_chip(struct pwm_chip *chip)
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{
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return container_of(chip, struct ab8500_pwm_chip, chip);
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}
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static int ab8500_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm,
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const struct pwm_state *state)
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{
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int ret;
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u8 reg;
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unsigned int higher_val, lower_val;
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struct ab8500_pwm_chip *ab8500 = ab8500_pwm_from_chip(chip);
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if (state->polarity != PWM_POLARITY_NORMAL)
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return -EINVAL;
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if (!state->enabled) {
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ret = abx500_mask_and_set_register_interruptible(chip->dev,
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AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
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1 << ab8500->hwid, 0);
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if (ret < 0)
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dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
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pwm->label, ret);
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return ret;
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}
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/*
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* get the first 8 bits that are be written to
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* AB8500_PWM_OUT_CTRL1_REG[0:7]
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*/
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lower_val = state->duty_cycle & 0x00FF;
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/*
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* get bits [9:10] that are to be written to
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* AB8500_PWM_OUT_CTRL2_REG[0:1]
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*/
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higher_val = ((state->duty_cycle & 0x0300) >> 8);
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reg = AB8500_PWM_OUT_CTRL1_REG + (ab8500->hwid * 2);
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ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
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reg, (u8)lower_val);
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if (ret < 0)
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return ret;
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ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
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(reg + 1), (u8)higher_val);
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if (ret < 0)
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return ret;
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ret = abx500_mask_and_set_register_interruptible(chip->dev,
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AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
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1 << ab8500->hwid, 1 << ab8500->hwid);
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if (ret < 0)
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dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n",
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pwm->label, ret);
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return ret;
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}
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static const struct pwm_ops ab8500_pwm_ops = {
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.apply = ab8500_pwm_apply,
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.owner = THIS_MODULE,
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};
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static int ab8500_pwm_probe(struct platform_device *pdev)
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{
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struct ab8500_pwm_chip *ab8500;
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int err;
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if (pdev->id < 1 || pdev->id > 31)
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return dev_err_probe(&pdev->dev, EINVAL, "Invalid device id %d\n", pdev->id);
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/*
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* Nothing to be done in probe, this is required to get the
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* device which is required for ab8500 read and write
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*/
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ab8500 = devm_kzalloc(&pdev->dev, sizeof(*ab8500), GFP_KERNEL);
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if (ab8500 == NULL)
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return -ENOMEM;
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ab8500->chip.dev = &pdev->dev;
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ab8500->chip.ops = &ab8500_pwm_ops;
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ab8500->chip.npwm = 1;
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ab8500->hwid = pdev->id - 1;
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err = devm_pwmchip_add(&pdev->dev, &ab8500->chip);
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if (err < 0)
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return dev_err_probe(&pdev->dev, err, "Failed to add pwm chip\n");
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dev_dbg(&pdev->dev, "pwm probe successful\n");
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return 0;
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}
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static struct platform_driver ab8500_pwm_driver = {
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.driver = {
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.name = "ab8500-pwm",
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},
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.probe = ab8500_pwm_probe,
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};
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module_platform_driver(ab8500_pwm_driver);
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MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>");
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MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
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MODULE_ALIAS("platform:ab8500-pwm");
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MODULE_LICENSE("GPL v2");
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