xref: /openbmc/linux/drivers/pwm/pwm-ab8500.c (revision af873fce)
1af873fceSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
26173f8f4SThierry Reding /*
36173f8f4SThierry Reding  * Copyright (C) ST-Ericsson SA 2010
46173f8f4SThierry Reding  *
56173f8f4SThierry Reding  * Author: Arun R Murthy <arun.murthy@stericsson.com>
66173f8f4SThierry Reding  */
76173f8f4SThierry Reding #include <linux/err.h>
86173f8f4SThierry Reding #include <linux/platform_device.h>
96173f8f4SThierry Reding #include <linux/slab.h>
106173f8f4SThierry Reding #include <linux/pwm.h>
116173f8f4SThierry Reding #include <linux/mfd/abx500.h>
126173f8f4SThierry Reding #include <linux/mfd/abx500/ab8500.h>
136173f8f4SThierry Reding #include <linux/module.h>
146173f8f4SThierry Reding 
156173f8f4SThierry Reding /*
166173f8f4SThierry Reding  * PWM Out generators
176173f8f4SThierry Reding  * Bank: 0x10
186173f8f4SThierry Reding  */
196173f8f4SThierry Reding #define AB8500_PWM_OUT_CTRL1_REG	0x60
206173f8f4SThierry Reding #define AB8500_PWM_OUT_CTRL2_REG	0x61
216173f8f4SThierry Reding #define AB8500_PWM_OUT_CTRL7_REG	0x66
226173f8f4SThierry Reding 
236173f8f4SThierry Reding struct ab8500_pwm_chip {
246173f8f4SThierry Reding 	struct pwm_chip chip;
256173f8f4SThierry Reding };
266173f8f4SThierry Reding 
276173f8f4SThierry Reding static int ab8500_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
286173f8f4SThierry Reding 			     int duty_ns, int period_ns)
296173f8f4SThierry Reding {
306173f8f4SThierry Reding 	int ret = 0;
316173f8f4SThierry Reding 	unsigned int higher_val, lower_val;
326173f8f4SThierry Reding 	u8 reg;
336173f8f4SThierry Reding 
346173f8f4SThierry Reding 	/*
356173f8f4SThierry Reding 	 * get the first 8 bits that are be written to
366173f8f4SThierry Reding 	 * AB8500_PWM_OUT_CTRL1_REG[0:7]
376173f8f4SThierry Reding 	 */
386173f8f4SThierry Reding 	lower_val = duty_ns & 0x00FF;
396173f8f4SThierry Reding 	/*
406173f8f4SThierry Reding 	 * get bits [9:10] that are to be written to
416173f8f4SThierry Reding 	 * AB8500_PWM_OUT_CTRL2_REG[0:1]
426173f8f4SThierry Reding 	 */
436173f8f4SThierry Reding 	higher_val = ((duty_ns & 0x0300) >> 8);
446173f8f4SThierry Reding 
456173f8f4SThierry Reding 	reg = AB8500_PWM_OUT_CTRL1_REG + ((chip->base - 1) * 2);
466173f8f4SThierry Reding 
476173f8f4SThierry Reding 	ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
486173f8f4SThierry Reding 			reg, (u8)lower_val);
496173f8f4SThierry Reding 	if (ret < 0)
506173f8f4SThierry Reding 		return ret;
516173f8f4SThierry Reding 	ret = abx500_set_register_interruptible(chip->dev, AB8500_MISC,
526173f8f4SThierry Reding 			(reg + 1), (u8)higher_val);
536173f8f4SThierry Reding 
546173f8f4SThierry Reding 	return ret;
556173f8f4SThierry Reding }
566173f8f4SThierry Reding 
576173f8f4SThierry Reding static int ab8500_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
586173f8f4SThierry Reding {
596173f8f4SThierry Reding 	int ret;
606173f8f4SThierry Reding 
616173f8f4SThierry Reding 	ret = abx500_mask_and_set_register_interruptible(chip->dev,
626173f8f4SThierry Reding 				AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
6354b02347SAxel Lin 				1 << (chip->base - 1), 1 << (chip->base - 1));
646173f8f4SThierry Reding 	if (ret < 0)
65622fc5d4SAxel Lin 		dev_err(chip->dev, "%s: Failed to enable PWM, Error %d\n",
666173f8f4SThierry Reding 							pwm->label, ret);
676173f8f4SThierry Reding 	return ret;
686173f8f4SThierry Reding }
696173f8f4SThierry Reding 
706173f8f4SThierry Reding static void ab8500_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
716173f8f4SThierry Reding {
726173f8f4SThierry Reding 	int ret;
736173f8f4SThierry Reding 
746173f8f4SThierry Reding 	ret = abx500_mask_and_set_register_interruptible(chip->dev,
756173f8f4SThierry Reding 				AB8500_MISC, AB8500_PWM_OUT_CTRL7_REG,
7654b02347SAxel Lin 				1 << (chip->base - 1), 0);
776173f8f4SThierry Reding 	if (ret < 0)
786173f8f4SThierry Reding 		dev_err(chip->dev, "%s: Failed to disable PWM, Error %d\n",
796173f8f4SThierry Reding 							pwm->label, ret);
806173f8f4SThierry Reding }
816173f8f4SThierry Reding 
826173f8f4SThierry Reding static const struct pwm_ops ab8500_pwm_ops = {
836173f8f4SThierry Reding 	.config = ab8500_pwm_config,
846173f8f4SThierry Reding 	.enable = ab8500_pwm_enable,
856173f8f4SThierry Reding 	.disable = ab8500_pwm_disable,
86fa0abee9SAxel Lin 	.owner = THIS_MODULE,
876173f8f4SThierry Reding };
886173f8f4SThierry Reding 
893e9fe83dSBill Pemberton static int ab8500_pwm_probe(struct platform_device *pdev)
906173f8f4SThierry Reding {
916173f8f4SThierry Reding 	struct ab8500_pwm_chip *ab8500;
926173f8f4SThierry Reding 	int err;
936173f8f4SThierry Reding 
946173f8f4SThierry Reding 	/*
956173f8f4SThierry Reding 	 * Nothing to be done in probe, this is required to get the
966173f8f4SThierry Reding 	 * device which is required for ab8500 read and write
976173f8f4SThierry Reding 	 */
98482467adSJingoo Han 	ab8500 = devm_kzalloc(&pdev->dev, sizeof(*ab8500), GFP_KERNEL);
99a2fc1db6SJingoo Han 	if (ab8500 == NULL)
1006173f8f4SThierry Reding 		return -ENOMEM;
1016173f8f4SThierry Reding 
1026173f8f4SThierry Reding 	ab8500->chip.dev = &pdev->dev;
1036173f8f4SThierry Reding 	ab8500->chip.ops = &ab8500_pwm_ops;
1046173f8f4SThierry Reding 	ab8500->chip.base = pdev->id;
1056173f8f4SThierry Reding 	ab8500->chip.npwm = 1;
1066173f8f4SThierry Reding 
1076173f8f4SThierry Reding 	err = pwmchip_add(&ab8500->chip);
108482467adSJingoo Han 	if (err < 0)
1096173f8f4SThierry Reding 		return err;
1106173f8f4SThierry Reding 
1116173f8f4SThierry Reding 	dev_dbg(&pdev->dev, "pwm probe successful\n");
1126173f8f4SThierry Reding 	platform_set_drvdata(pdev, ab8500);
1136173f8f4SThierry Reding 
1146173f8f4SThierry Reding 	return 0;
1156173f8f4SThierry Reding }
1166173f8f4SThierry Reding 
11777f37917SBill Pemberton static int ab8500_pwm_remove(struct platform_device *pdev)
1186173f8f4SThierry Reding {
1196173f8f4SThierry Reding 	struct ab8500_pwm_chip *ab8500 = platform_get_drvdata(pdev);
1206173f8f4SThierry Reding 	int err;
1216173f8f4SThierry Reding 
1226173f8f4SThierry Reding 	err = pwmchip_remove(&ab8500->chip);
1236173f8f4SThierry Reding 	if (err < 0)
1246173f8f4SThierry Reding 		return err;
1256173f8f4SThierry Reding 
1266173f8f4SThierry Reding 	dev_dbg(&pdev->dev, "pwm driver removed\n");
1276173f8f4SThierry Reding 
1286173f8f4SThierry Reding 	return 0;
1296173f8f4SThierry Reding }
1306173f8f4SThierry Reding 
1316173f8f4SThierry Reding static struct platform_driver ab8500_pwm_driver = {
1326173f8f4SThierry Reding 	.driver = {
1336173f8f4SThierry Reding 		.name = "ab8500-pwm",
1346173f8f4SThierry Reding 	},
1356173f8f4SThierry Reding 	.probe = ab8500_pwm_probe,
136fd109112SBill Pemberton 	.remove = ab8500_pwm_remove,
1376173f8f4SThierry Reding };
1386173f8f4SThierry Reding module_platform_driver(ab8500_pwm_driver);
1396173f8f4SThierry Reding 
1406173f8f4SThierry Reding MODULE_AUTHOR("Arun MURTHY <arun.murthy@stericsson.com>");
1416173f8f4SThierry Reding MODULE_DESCRIPTION("AB8500 Pulse Width Modulation Driver");
1426173f8f4SThierry Reding MODULE_ALIAS("platform:ab8500-pwm");
1436173f8f4SThierry Reding MODULE_LICENSE("GPL v2");
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