1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Core driver for HTC PASIC3 LED/DS1WM chip.
4 *
5 * Copyright (C) 2006 Philipp Zabel <philipp.zabel@gmail.com>
6 */
7
8#include <linux/init.h>
9#include <linux/module.h>
10#include <linux/platform_device.h>
11
12#include <linux/gpio.h>
13#include <linux/io.h>
14#include <linux/irq.h>
15#include <linux/interrupt.h>
16#include <linux/mfd/core.h>
17#include <linux/mfd/ds1wm.h>
18#include <linux/mfd/htc-pasic3.h>
19#include <linux/slab.h>
20
21struct pasic3_data {
22	void __iomem *mapping;
23	unsigned int bus_shift;
24};
25
26#define REG_ADDR  5
27#define REG_DATA  6
28
29#define READ_MODE 0x80
30
31/*
32 * write to a secondary register on the PASIC3
33 */
34void pasic3_write_register(struct device *dev, u32 reg, u8 val)
35{
36	struct pasic3_data *asic = dev_get_drvdata(dev);
37	int bus_shift = asic->bus_shift;
38	void __iomem *addr = asic->mapping + (REG_ADDR << bus_shift);
39	void __iomem *data = asic->mapping + (REG_DATA << bus_shift);
40
41	__raw_writeb(~READ_MODE & reg, addr);
42	__raw_writeb(val, data);
43}
44EXPORT_SYMBOL(pasic3_write_register); /* for leds-pasic3 */
45
46/*
47 * read from a secondary register on the PASIC3
48 */
49u8 pasic3_read_register(struct device *dev, u32 reg)
50{
51	struct pasic3_data *asic = dev_get_drvdata(dev);
52	int bus_shift = asic->bus_shift;
53	void __iomem *addr = asic->mapping + (REG_ADDR << bus_shift);
54	void __iomem *data = asic->mapping + (REG_DATA << bus_shift);
55
56	__raw_writeb(READ_MODE | reg, addr);
57	return __raw_readb(data);
58}
59EXPORT_SYMBOL(pasic3_read_register); /* for leds-pasic3 */
60
61/*
62 * LEDs
63 */
64
65static struct mfd_cell led_cell __initdata = {
66	.name = "leds-pasic3",
67};
68
69/*
70 * DS1WM
71 */
72
73static int ds1wm_enable(struct platform_device *pdev)
74{
75	struct device *dev = pdev->dev.parent;
76	int c;
77
78	c = pasic3_read_register(dev, 0x28);
79	pasic3_write_register(dev, 0x28, c & 0x7f);
80
81	dev_dbg(dev, "DS1WM OWM_EN low (active) %02x\n", c & 0x7f);
82	return 0;
83}
84
85static int ds1wm_disable(struct platform_device *pdev)
86{
87	struct device *dev = pdev->dev.parent;
88	int c;
89
90	c = pasic3_read_register(dev, 0x28);
91	pasic3_write_register(dev, 0x28, c | 0x80);
92
93	dev_dbg(dev, "DS1WM OWM_EN high (inactive) %02x\n", c | 0x80);
94	return 0;
95}
96
97static struct ds1wm_driver_data ds1wm_pdata = {
98	.active_high = 0,
99	.reset_recover_delay = 1,
100};
101
102static struct resource ds1wm_resources[] __initdata = {
103	[0] = {
104		.start  = 0,
105		.flags  = IORESOURCE_MEM,
106	},
107	[1] = {
108		.start  = 0,
109		.end    = 0,
110		.flags  = IORESOURCE_IRQ,
111	},
112};
113
114static const struct mfd_cell ds1wm_cell __initconst = {
115	.name          = "ds1wm",
116	.enable        = ds1wm_enable,
117	.disable       = ds1wm_disable,
118	.platform_data = &ds1wm_pdata,
119	.pdata_size    = sizeof(ds1wm_pdata),
120	.num_resources = 2,
121	.resources     = ds1wm_resources,
122};
123
124static int __init pasic3_probe(struct platform_device *pdev)
125{
126	struct pasic3_platform_data *pdata = dev_get_platdata(&pdev->dev);
127	struct device *dev = &pdev->dev;
128	struct pasic3_data *asic;
129	struct resource *r;
130	int ret;
131	int irq = 0;
132
133	r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
134	if (r) {
135		ds1wm_resources[1].flags = IORESOURCE_IRQ | (r->flags &
136			(IORESOURCE_IRQ_HIGHEDGE | IORESOURCE_IRQ_LOWEDGE));
137		irq = r->start;
138	}
139
140	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
141	if (!r)
142		return -ENXIO;
143
144	if (!request_mem_region(r->start, resource_size(r), "pasic3"))
145		return -EBUSY;
146
147	asic = devm_kzalloc(dev, sizeof(struct pasic3_data), GFP_KERNEL);
148	if (!asic)
149		return -ENOMEM;
150
151	platform_set_drvdata(pdev, asic);
152
153	asic->mapping = ioremap(r->start, resource_size(r));
154	if (!asic->mapping) {
155		dev_err(dev, "couldn't ioremap PASIC3\n");
156		return -ENOMEM;
157	}
158
159	/* calculate bus shift from mem resource */
160	asic->bus_shift = (resource_size(r) - 5) >> 3;
161
162	if (pdata && pdata->clock_rate) {
163		ds1wm_pdata.clock_rate = pdata->clock_rate;
164		/* the first 5 PASIC3 registers control the DS1WM */
165		ds1wm_resources[0].end = (5 << asic->bus_shift) - 1;
166		ret = mfd_add_devices(&pdev->dev, pdev->id,
167				      &ds1wm_cell, 1, r, irq, NULL);
168		if (ret < 0)
169			dev_warn(dev, "failed to register DS1WM\n");
170	}
171
172	if (pdata && pdata->led_pdata) {
173		led_cell.platform_data = pdata->led_pdata;
174		led_cell.pdata_size = sizeof(struct pasic3_leds_machinfo);
175		ret = mfd_add_devices(&pdev->dev, pdev->id, &led_cell, 1, r,
176				      0, NULL);
177		if (ret < 0)
178			dev_warn(dev, "failed to register LED device\n");
179	}
180
181	return 0;
182}
183
184static int pasic3_remove(struct platform_device *pdev)
185{
186	struct pasic3_data *asic = platform_get_drvdata(pdev);
187	struct resource *r;
188
189	mfd_remove_devices(&pdev->dev);
190
191	iounmap(asic->mapping);
192	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
193	release_mem_region(r->start, resource_size(r));
194	return 0;
195}
196
197MODULE_ALIAS("platform:pasic3");
198
199static struct platform_driver pasic3_driver = {
200	.driver		= {
201		.name	= "pasic3",
202	},
203	.remove		= pasic3_remove,
204};
205
206module_platform_driver_probe(pasic3_driver, pasic3_probe);
207
208MODULE_AUTHOR("Philipp Zabel <philipp.zabel@gmail.com>");
209MODULE_DESCRIPTION("Core driver for HTC PASIC3");
210MODULE_LICENSE("GPL");
211