1// SPDX-License-Identifier: GPL-2.0+
2// Copyright (C) 2008-2009 The GameCube Linux Team
3// Copyright (C) 2008,2009 Albert Herranz
4// Copyright (C) 2017-2018 Jonathan Neuschäfer
5//
6// Nintendo Wii (Hollywood) GPIO driver
7
8#include <linux/gpio/driver.h>
9#include <linux/io.h>
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/of.h>
13#include <linux/of_platform.h>
14#include <linux/slab.h>
15
16/*
17 * Register names and offsets courtesy of WiiBrew:
18 * https://wiibrew.org/wiki/Hardware/Hollywood_GPIOs
19 *
20 * Note that for most registers, there are two versions:
21 * - HW_GPIOB_* Is always accessible by the Broadway PowerPC core, but does
22 * always give access to all GPIO lines
23 * - HW_GPIO_* Is only accessible by the Broadway PowerPC code if the memory
24 * firewall (AHBPROT) in the Hollywood chipset has been configured to allow
25 * such access.
26 *
27 * The ownership of each GPIO line can be configured in the HW_GPIO_OWNER
28 * register: A one bit configures the line for access via the HW_GPIOB_*
29 * registers, a zero bit indicates access via HW_GPIO_*. This driver uses
30 * HW_GPIOB_*.
31 */
32#define HW_GPIOB_OUT 0x00
33#define HW_GPIOB_DIR 0x04
34#define HW_GPIOB_IN 0x08
35#define HW_GPIOB_INTLVL 0x0c
36#define HW_GPIOB_INTFLAG 0x10
37#define HW_GPIOB_INTMASK 0x14
38#define HW_GPIOB_INMIR 0x18
39#define HW_GPIO_ENABLE 0x1c
40#define HW_GPIO_OUT 0x20
41#define HW_GPIO_DIR 0x24
42#define HW_GPIO_IN 0x28
43#define HW_GPIO_INTLVL 0x2c
44#define HW_GPIO_INTFLAG 0x30
45#define HW_GPIO_INTMASK 0x34
46#define HW_GPIO_INMIR 0x38
47#define HW_GPIO_OWNER 0x3c
48
49struct hlwd_gpio {
50 struct gpio_chip gpioc;
51 struct irq_chip irqc;
52 void __iomem *regs;
53 int irq;
54 u32 edge_emulation;
55 u32 rising_edge, falling_edge;
56};
57
58static void hlwd_gpio_irqhandler(struct irq_desc *desc)
59{
60 struct hlwd_gpio *hlwd =
61 gpiochip_get_data(irq_desc_get_handler_data(desc));
62 struct irq_chip *chip = irq_desc_get_chip(desc);
63 unsigned long flags;
64 unsigned long pending;
65 int hwirq;
66 u32 emulated_pending;
67
68 spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags);
69 pending = ioread32be(hlwd->regs + HW_GPIOB_INTFLAG);
70 pending &= ioread32be(hlwd->regs + HW_GPIOB_INTMASK);
71
72 /* Treat interrupts due to edge trigger emulation separately */
73 emulated_pending = hlwd->edge_emulation & pending;
74 pending &= ~emulated_pending;
75 if (emulated_pending) {
76 u32 level, rising, falling;
77
78 level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL);
79 rising = level & emulated_pending;
80 falling = ~level & emulated_pending;
81
82 /* Invert the levels */
83 iowrite32be(level ^ emulated_pending,
84 hlwd->regs + HW_GPIOB_INTLVL);
85
86 /* Ack all emulated-edge interrupts */
87 iowrite32be(emulated_pending, hlwd->regs + HW_GPIOB_INTFLAG);
88
89 /* Signal interrupts only on the correct edge */
90 rising &= hlwd->rising_edge;
91 falling &= hlwd->falling_edge;
92
93 /* Mark emulated interrupts as pending */
94 pending |= rising | falling;
95 }
96 spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags);
97
98 chained_irq_enter(chip, desc);
99
100 for_each_set_bit(hwirq, &pending, 32) {
101 int irq = irq_find_mapping(hlwd->gpioc.irq.domain, hwirq);
102
103 generic_handle_irq(irq);
104 }
105
106 chained_irq_exit(chip, desc);
107}
108
109static void hlwd_gpio_irq_ack(struct irq_data *data)
110{
111 struct hlwd_gpio *hlwd =
112 gpiochip_get_data(irq_data_get_irq_chip_data(data));
113
114 iowrite32be(BIT(data->hwirq), hlwd->regs + HW_GPIOB_INTFLAG);
115}
116
117static void hlwd_gpio_irq_mask(struct irq_data *data)
118{
119 struct hlwd_gpio *hlwd =
120 gpiochip_get_data(irq_data_get_irq_chip_data(data));
121 unsigned long flags;
122 u32 mask;
123
124 spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags);
125 mask = ioread32be(hlwd->regs + HW_GPIOB_INTMASK);
126 mask &= ~BIT(data->hwirq);
127 iowrite32be(mask, hlwd->regs + HW_GPIOB_INTMASK);
128 spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags);
129}
130
131static void hlwd_gpio_irq_unmask(struct irq_data *data)
132{
133 struct hlwd_gpio *hlwd =
134 gpiochip_get_data(irq_data_get_irq_chip_data(data));
135 unsigned long flags;
136 u32 mask;
137
138 spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags);
139 mask = ioread32be(hlwd->regs + HW_GPIOB_INTMASK);
140 mask |= BIT(data->hwirq);
141 iowrite32be(mask, hlwd->regs + HW_GPIOB_INTMASK);
142 spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags);
143}
144
145static void hlwd_gpio_irq_enable(struct irq_data *data)
146{
147 hlwd_gpio_irq_ack(data);
148 hlwd_gpio_irq_unmask(data);
149}
150
151static void hlwd_gpio_irq_setup_emulation(struct hlwd_gpio *hlwd, int hwirq,
152 unsigned int flow_type)
153{
154 u32 level, state;
155
156 /* Set the trigger level to the inactive level */
157 level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL);
158 state = ioread32be(hlwd->regs + HW_GPIOB_IN) & BIT(hwirq);
159 level &= ~BIT(hwirq);
160 level |= state ^ BIT(hwirq);
161 iowrite32be(level, hlwd->regs + HW_GPIOB_INTLVL);
162
163 hlwd->edge_emulation |= BIT(hwirq);
164 hlwd->rising_edge &= ~BIT(hwirq);
165 hlwd->falling_edge &= ~BIT(hwirq);
166 if (flow_type & IRQ_TYPE_EDGE_RISING)
167 hlwd->rising_edge |= BIT(hwirq);
168 if (flow_type & IRQ_TYPE_EDGE_FALLING)
169 hlwd->falling_edge |= BIT(hwirq);
170}
171
172static int hlwd_gpio_irq_set_type(struct irq_data *data, unsigned int flow_type)
173{
174 struct hlwd_gpio *hlwd =
175 gpiochip_get_data(irq_data_get_irq_chip_data(data));
176 unsigned long flags;
177 u32 level;
178
179 spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags);
180
181 hlwd->edge_emulation &= ~BIT(data->hwirq);
182
183 switch (flow_type) {
184 case IRQ_TYPE_LEVEL_HIGH:
185 level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL);
186 level |= BIT(data->hwirq);
187 iowrite32be(level, hlwd->regs + HW_GPIOB_INTLVL);
188 break;
189 case IRQ_TYPE_LEVEL_LOW:
190 level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL);
191 level &= ~BIT(data->hwirq);
192 iowrite32be(level, hlwd->regs + HW_GPIOB_INTLVL);
193 break;
194 case IRQ_TYPE_EDGE_RISING:
195 case IRQ_TYPE_EDGE_FALLING:
196 case IRQ_TYPE_EDGE_BOTH:
197 hlwd_gpio_irq_setup_emulation(hlwd, data->hwirq, flow_type);
198 break;
199 default:
200 spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags);
201 return -EINVAL;
202 }
203
204 spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags);
205 return 0;
206}
207
208static int hlwd_gpio_probe(struct platform_device *pdev)
209{
210 struct hlwd_gpio *hlwd;
211 struct resource *regs_resource;
212 u32 ngpios;
213 int res;
214
215 hlwd = devm_kzalloc(&pdev->dev, sizeof(*hlwd), GFP_KERNEL);
216 if (!hlwd)
217 return -ENOMEM;
218
219 regs_resource = platform_get_resource(pdev, IORESOURCE_MEM, 0);
220 hlwd->regs = devm_ioremap_resource(&pdev->dev, regs_resource);
221 if (IS_ERR(hlwd->regs))
222 return PTR_ERR(hlwd->regs);
223
224 /*
225 * Claim all GPIOs using the OWNER register. This will not work on
226 * systems where the AHBPROT memory firewall hasn't been configured to
227 * permit PPC access to HW_GPIO_*.
228 *
229 * Note that this has to happen before bgpio_init reads the
230 * HW_GPIOB_OUT and HW_GPIOB_DIR, because otherwise it reads the wrong
231 * values.
232 */
233 iowrite32be(0xffffffff, hlwd->regs + HW_GPIO_OWNER);
234
235 res = bgpio_init(&hlwd->gpioc, &pdev->dev, 4,
236 hlwd->regs + HW_GPIOB_IN, hlwd->regs + HW_GPIOB_OUT,
237 NULL, hlwd->regs + HW_GPIOB_DIR, NULL,
238 BGPIOF_BIG_ENDIAN_BYTE_ORDER);
239 if (res < 0) {
240 dev_warn(&pdev->dev, "bgpio_init failed: %d\n", res);
241 return res;
242 }
243
244 res = of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios);
245 if (res)
246 ngpios = 32;
247 hlwd->gpioc.ngpio = ngpios;
248
249 res = devm_gpiochip_add_data(&pdev->dev, &hlwd->gpioc, hlwd);
250 if (res)
251 return res;
252
253 /* Mask and ack all interrupts */
254 iowrite32be(0, hlwd->regs + HW_GPIOB_INTMASK);
255 iowrite32be(0xffffffff, hlwd->regs + HW_GPIOB_INTFLAG);
256
257 /*
258 * If this GPIO controller is not marked as an interrupt controller in
259 * the DT, return.
260 */
261 if (!of_property_read_bool(pdev->dev.of_node, "interrupt-controller"))
262 return 0;
263
264 hlwd->irq = platform_get_irq(pdev, 0);
265 if (hlwd->irq < 0) {
266 dev_info(&pdev->dev, "platform_get_irq returned %d\n",
267 hlwd->irq);
268 return hlwd->irq;
269 }
270
271 hlwd->irqc.name = dev_name(&pdev->dev);
272 hlwd->irqc.irq_mask = hlwd_gpio_irq_mask;
273 hlwd->irqc.irq_unmask = hlwd_gpio_irq_unmask;
274 hlwd->irqc.irq_enable = hlwd_gpio_irq_enable;
275 hlwd->irqc.irq_set_type = hlwd_gpio_irq_set_type;
276
277 res = gpiochip_irqchip_add(&hlwd->gpioc, &hlwd->irqc, 0,
278 handle_level_irq, IRQ_TYPE_NONE);
279 if (res)
280 return res;
281
282 gpiochip_set_chained_irqchip(&hlwd->gpioc, &hlwd->irqc,
283 hlwd->irq, hlwd_gpio_irqhandler);
284
285 return 0;
286}
287
288static const struct of_device_id hlwd_gpio_match[] = {
289 { .compatible = "nintendo,hollywood-gpio", },
290 {},
291};
292MODULE_DEVICE_TABLE(of, hlwd_gpio_match);
293
294static struct platform_driver hlwd_gpio_driver = {
295 .driver = {
296 .name = "gpio-hlwd",
297 .of_match_table = hlwd_gpio_match,
298 },
299 .probe = hlwd_gpio_probe,
300};
301module_platform_driver(hlwd_gpio_driver);
302
303MODULE_AUTHOR("Jonathan Neuschäfer <j.neuschaefer@gmx.net>");
304MODULE_DESCRIPTION("Nintendo Wii GPIO driver");
305MODULE_LICENSE("GPL");
306