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1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/drivers/gpio/gpio-mb86s7x.c
4  *
5  *  Copyright (C) 2015 Fujitsu Semiconductor Limited
6  *  Copyright (C) 2015 Linaro Ltd.
7  */
8 
9 #include <linux/acpi.h>
10 #include <linux/io.h>
11 #include <linux/init.h>
12 #include <linux/clk.h>
13 #include <linux/module.h>
14 #include <linux/err.h>
15 #include <linux/errno.h>
16 #include <linux/ioport.h>
17 #include <linux/of_device.h>
18 #include <linux/gpio/driver.h>
19 #include <linux/platform_device.h>
20 #include <linux/spinlock.h>
21 #include <linux/slab.h>
22 
23 #include "gpiolib.h"
24 #include "gpiolib-acpi.h"
25 
26 /*
27  * Only first 8bits of a register correspond to each pin,
28  * so there are 4 registers for 32 pins.
29  */
30 #define PDR(x)	(0x0 + x / 8 * 4)
31 #define DDR(x)	(0x10 + x / 8 * 4)
32 #define PFR(x)	(0x20 + x / 8 * 4)
33 
34 #define OFFSET(x)	BIT((x) % 8)
35 
36 struct mb86s70_gpio_chip {
37 	struct gpio_chip gc;
38 	void __iomem *base;
39 	struct clk *clk;
40 	spinlock_t lock;
41 };
42 
mb86s70_gpio_request(struct gpio_chip * gc,unsigned gpio)43 static int mb86s70_gpio_request(struct gpio_chip *gc, unsigned gpio)
44 {
45 	struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
46 	unsigned long flags;
47 	u32 val;
48 
49 	spin_lock_irqsave(&gchip->lock, flags);
50 
51 	val = readl(gchip->base + PFR(gpio));
52 	val &= ~OFFSET(gpio);
53 	writel(val, gchip->base + PFR(gpio));
54 
55 	spin_unlock_irqrestore(&gchip->lock, flags);
56 
57 	return 0;
58 }
59 
mb86s70_gpio_free(struct gpio_chip * gc,unsigned gpio)60 static void mb86s70_gpio_free(struct gpio_chip *gc, unsigned gpio)
61 {
62 	struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
63 	unsigned long flags;
64 	u32 val;
65 
66 	spin_lock_irqsave(&gchip->lock, flags);
67 
68 	val = readl(gchip->base + PFR(gpio));
69 	val |= OFFSET(gpio);
70 	writel(val, gchip->base + PFR(gpio));
71 
72 	spin_unlock_irqrestore(&gchip->lock, flags);
73 }
74 
mb86s70_gpio_direction_input(struct gpio_chip * gc,unsigned gpio)75 static int mb86s70_gpio_direction_input(struct gpio_chip *gc, unsigned gpio)
76 {
77 	struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
78 	unsigned long flags;
79 	unsigned char val;
80 
81 	spin_lock_irqsave(&gchip->lock, flags);
82 
83 	val = readl(gchip->base + DDR(gpio));
84 	val &= ~OFFSET(gpio);
85 	writel(val, gchip->base + DDR(gpio));
86 
87 	spin_unlock_irqrestore(&gchip->lock, flags);
88 
89 	return 0;
90 }
91 
mb86s70_gpio_direction_output(struct gpio_chip * gc,unsigned gpio,int value)92 static int mb86s70_gpio_direction_output(struct gpio_chip *gc,
93 					 unsigned gpio, int value)
94 {
95 	struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
96 	unsigned long flags;
97 	unsigned char val;
98 
99 	spin_lock_irqsave(&gchip->lock, flags);
100 
101 	val = readl(gchip->base + PDR(gpio));
102 	if (value)
103 		val |= OFFSET(gpio);
104 	else
105 		val &= ~OFFSET(gpio);
106 	writel(val, gchip->base + PDR(gpio));
107 
108 	val = readl(gchip->base + DDR(gpio));
109 	val |= OFFSET(gpio);
110 	writel(val, gchip->base + DDR(gpio));
111 
112 	spin_unlock_irqrestore(&gchip->lock, flags);
113 
114 	return 0;
115 }
116 
mb86s70_gpio_get(struct gpio_chip * gc,unsigned gpio)117 static int mb86s70_gpio_get(struct gpio_chip *gc, unsigned gpio)
118 {
119 	struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
120 
121 	return !!(readl(gchip->base + PDR(gpio)) & OFFSET(gpio));
122 }
123 
mb86s70_gpio_set(struct gpio_chip * gc,unsigned gpio,int value)124 static void mb86s70_gpio_set(struct gpio_chip *gc, unsigned gpio, int value)
125 {
126 	struct mb86s70_gpio_chip *gchip = gpiochip_get_data(gc);
127 	unsigned long flags;
128 	unsigned char val;
129 
130 	spin_lock_irqsave(&gchip->lock, flags);
131 
132 	val = readl(gchip->base + PDR(gpio));
133 	if (value)
134 		val |= OFFSET(gpio);
135 	else
136 		val &= ~OFFSET(gpio);
137 	writel(val, gchip->base + PDR(gpio));
138 
139 	spin_unlock_irqrestore(&gchip->lock, flags);
140 }
141 
mb86s70_gpio_to_irq(struct gpio_chip * gc,unsigned int offset)142 static int mb86s70_gpio_to_irq(struct gpio_chip *gc, unsigned int offset)
143 {
144 	int irq, index;
145 
146 	for (index = 0;; index++) {
147 		irq = platform_get_irq(to_platform_device(gc->parent), index);
148 		if (irq <= 0)
149 			break;
150 		if (irq_get_irq_data(irq)->hwirq == offset)
151 			return irq;
152 	}
153 	return -EINVAL;
154 }
155 
mb86s70_gpio_probe(struct platform_device * pdev)156 static int mb86s70_gpio_probe(struct platform_device *pdev)
157 {
158 	struct mb86s70_gpio_chip *gchip;
159 	int ret;
160 
161 	gchip = devm_kzalloc(&pdev->dev, sizeof(*gchip), GFP_KERNEL);
162 	if (gchip == NULL)
163 		return -ENOMEM;
164 
165 	platform_set_drvdata(pdev, gchip);
166 
167 	gchip->base = devm_platform_ioremap_resource(pdev, 0);
168 	if (IS_ERR(gchip->base))
169 		return PTR_ERR(gchip->base);
170 
171 	if (!has_acpi_companion(&pdev->dev)) {
172 		gchip->clk = devm_clk_get(&pdev->dev, NULL);
173 		if (IS_ERR(gchip->clk))
174 			return PTR_ERR(gchip->clk);
175 
176 		ret = clk_prepare_enable(gchip->clk);
177 		if (ret)
178 			return ret;
179 	}
180 
181 	spin_lock_init(&gchip->lock);
182 
183 	gchip->gc.direction_output = mb86s70_gpio_direction_output;
184 	gchip->gc.direction_input = mb86s70_gpio_direction_input;
185 	gchip->gc.request = mb86s70_gpio_request;
186 	gchip->gc.free = mb86s70_gpio_free;
187 	gchip->gc.get = mb86s70_gpio_get;
188 	gchip->gc.set = mb86s70_gpio_set;
189 	gchip->gc.label = dev_name(&pdev->dev);
190 	gchip->gc.ngpio = 32;
191 	gchip->gc.owner = THIS_MODULE;
192 	gchip->gc.parent = &pdev->dev;
193 	gchip->gc.base = -1;
194 
195 	if (has_acpi_companion(&pdev->dev))
196 		gchip->gc.to_irq = mb86s70_gpio_to_irq;
197 
198 	ret = gpiochip_add_data(&gchip->gc, gchip);
199 	if (ret) {
200 		dev_err(&pdev->dev, "couldn't register gpio driver\n");
201 		clk_disable_unprepare(gchip->clk);
202 		return ret;
203 	}
204 
205 	if (has_acpi_companion(&pdev->dev))
206 		acpi_gpiochip_request_interrupts(&gchip->gc);
207 
208 	return 0;
209 }
210 
mb86s70_gpio_remove(struct platform_device * pdev)211 static int mb86s70_gpio_remove(struct platform_device *pdev)
212 {
213 	struct mb86s70_gpio_chip *gchip = platform_get_drvdata(pdev);
214 
215 	if (has_acpi_companion(&pdev->dev))
216 		acpi_gpiochip_free_interrupts(&gchip->gc);
217 	gpiochip_remove(&gchip->gc);
218 	clk_disable_unprepare(gchip->clk);
219 
220 	return 0;
221 }
222 
223 static const struct of_device_id mb86s70_gpio_dt_ids[] = {
224 	{ .compatible = "fujitsu,mb86s70-gpio" },
225 	{ /* sentinel */ }
226 };
227 MODULE_DEVICE_TABLE(of, mb86s70_gpio_dt_ids);
228 
229 #ifdef CONFIG_ACPI
230 static const struct acpi_device_id mb86s70_gpio_acpi_ids[] = {
231 	{ "SCX0007" },
232 	{ /* sentinel */ }
233 };
234 MODULE_DEVICE_TABLE(acpi, mb86s70_gpio_acpi_ids);
235 #endif
236 
237 static struct platform_driver mb86s70_gpio_driver = {
238 	.driver = {
239 		.name = "mb86s70-gpio",
240 		.of_match_table = mb86s70_gpio_dt_ids,
241 		.acpi_match_table = ACPI_PTR(mb86s70_gpio_acpi_ids),
242 	},
243 	.probe = mb86s70_gpio_probe,
244 	.remove = mb86s70_gpio_remove,
245 };
246 module_platform_driver(mb86s70_gpio_driver);
247 
248 MODULE_DESCRIPTION("MB86S7x GPIO Driver");
249 MODULE_ALIAS("platform:mb86s70-gpio");
250 MODULE_LICENSE("GPL");
251