1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 *  Copyright (C) 2011 Paul Parsons <lost.distance@yahoo.com>
  4 */
  5
  6#include <linux/kernel.h>
  7#include <linux/platform_device.h>
  8#include <linux/leds.h>
  9#include <linux/slab.h>
 10
 11#include <linux/mfd/asic3.h>
 12#include <linux/mfd/core.h>
 13#include <linux/module.h>
 14
 15/*
 16 *	The HTC ASIC3 LED GPIOs are inputs, not outputs.
 17 *	Hence we turn the LEDs on/off via the TimeBase register.
 18 */
 19
 20/*
 21 *	When TimeBase is 4 the clock resolution is about 32Hz.
 22 *	This driver supports hardware blinking with an on+off
 23 *	period from 62ms (2 clocks) to 125s (4000 clocks).
 24 */
 25#define MS_TO_CLK(ms)	DIV_ROUND_CLOSEST(((ms)*1024), 32000)
 26#define CLK_TO_MS(clk)	(((clk)*32000)/1024)
 27#define MAX_CLK		4000            /* Fits into 12-bit Time registers */
 28#define MAX_MS		CLK_TO_MS(MAX_CLK)
 29
 30static const unsigned int led_n_base[ASIC3_NUM_LEDS] = {
 31	[0] = ASIC3_LED_0_Base,
 32	[1] = ASIC3_LED_1_Base,
 33	[2] = ASIC3_LED_2_Base,
 34};
 35
 36static void brightness_set(struct led_classdev *cdev,
 37	enum led_brightness value)
 38{
 39	struct platform_device *pdev = to_platform_device(cdev->dev->parent);
 40	const struct mfd_cell *cell = mfd_get_cell(pdev);
 41	struct asic3 *asic = dev_get_drvdata(pdev->dev.parent);
 42	u32 timebase;
 43	unsigned int base;
 44
 45	timebase = (value == LED_OFF) ? 0 : (LED_EN|0x4);
 46
 47	base = led_n_base[cell->id];
 48	asic3_write_register(asic, (base + ASIC3_LED_PeriodTime), 32);
 49	asic3_write_register(asic, (base + ASIC3_LED_DutyTime), 32);
 50	asic3_write_register(asic, (base + ASIC3_LED_AutoStopCount), 0);
 51	asic3_write_register(asic, (base + ASIC3_LED_TimeBase), timebase);
 52}
 53
 54static int blink_set(struct led_classdev *cdev,
 55	unsigned long *delay_on,
 56	unsigned long *delay_off)
 57{
 58	struct platform_device *pdev = to_platform_device(cdev->dev->parent);
 59	const struct mfd_cell *cell = mfd_get_cell(pdev);
 60	struct asic3 *asic = dev_get_drvdata(pdev->dev.parent);
 61	u32 on;
 62	u32 off;
 63	unsigned int base;
 64
 65	if (*delay_on > MAX_MS || *delay_off > MAX_MS)
 66		return -EINVAL;
 67
 68	if (*delay_on == 0 && *delay_off == 0) {
 69		/* If both are zero then a sensible default should be chosen */
 70		on = MS_TO_CLK(500);
 71		off = MS_TO_CLK(500);
 72	} else {
 73		on = MS_TO_CLK(*delay_on);
 74		off = MS_TO_CLK(*delay_off);
 75		if ((on + off) > MAX_CLK)
 76			return -EINVAL;
 77	}
 78
 79	base = led_n_base[cell->id];
 80	asic3_write_register(asic, (base + ASIC3_LED_PeriodTime), (on + off));
 81	asic3_write_register(asic, (base + ASIC3_LED_DutyTime), on);
 82	asic3_write_register(asic, (base + ASIC3_LED_AutoStopCount), 0);
 83	asic3_write_register(asic, (base + ASIC3_LED_TimeBase), (LED_EN|0x4));
 84
 85	*delay_on = CLK_TO_MS(on);
 86	*delay_off = CLK_TO_MS(off);
 87
 88	return 0;
 89}
 90
 91static int asic3_led_probe(struct platform_device *pdev)
 92{
 93	struct asic3_led *led = dev_get_platdata(&pdev->dev);
 94	int ret;
 95
 96	ret = mfd_cell_enable(pdev);
 97	if (ret < 0)
 98		return ret;
 99
100	led->cdev = devm_kzalloc(&pdev->dev, sizeof(struct led_classdev),
101				GFP_KERNEL);
102	if (!led->cdev) {
103		ret = -ENOMEM;
104		goto out;
105	}
106
107	led->cdev->name = led->name;
108	led->cdev->flags = LED_CORE_SUSPENDRESUME;
109	led->cdev->brightness_set = brightness_set;
110	led->cdev->blink_set = blink_set;
111	led->cdev->default_trigger = led->default_trigger;
112
113	ret = led_classdev_register(&pdev->dev, led->cdev);
114	if (ret < 0)
115		goto out;
116
117	return 0;
118
119out:
120	(void) mfd_cell_disable(pdev);
121	return ret;
122}
123
124static int asic3_led_remove(struct platform_device *pdev)
125{
126	struct asic3_led *led = dev_get_platdata(&pdev->dev);
127
128	led_classdev_unregister(led->cdev);
129
130	return mfd_cell_disable(pdev);
131}
132
133#ifdef CONFIG_PM_SLEEP
134static int asic3_led_suspend(struct device *dev)
135{
136	struct platform_device *pdev = to_platform_device(dev);
137	const struct mfd_cell *cell = mfd_get_cell(pdev);
138	int ret;
139
140	ret = 0;
141	if (cell->suspend)
142		ret = (*cell->suspend)(pdev);
143
144	return ret;
145}
146
147static int asic3_led_resume(struct device *dev)
148{
149	struct platform_device *pdev = to_platform_device(dev);
150	const struct mfd_cell *cell = mfd_get_cell(pdev);
151	int ret;
152
153	ret = 0;
154	if (cell->resume)
155		ret = (*cell->resume)(pdev);
156
157	return ret;
158}
159#endif
160
161static SIMPLE_DEV_PM_OPS(asic3_led_pm_ops, asic3_led_suspend, asic3_led_resume);
162
163static struct platform_driver asic3_led_driver = {
164	.probe		= asic3_led_probe,
165	.remove		= asic3_led_remove,
166	.driver		= {
167		.name	= "leds-asic3",
168		.pm	= &asic3_led_pm_ops,
169	},
170};
171
172module_platform_driver(asic3_led_driver);
173
174MODULE_AUTHOR("Paul Parsons <lost.distance@yahoo.com>");
175MODULE_DESCRIPTION("HTC ASIC3 LED driver");
176MODULE_LICENSE("GPL");
177MODULE_ALIAS("platform:leds-asic3");