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/seq_file.h> 15 #include <linux/slab.h> 16 17 /* 18 * Register names and offsets courtesy of WiiBrew: 19 * https://wiibrew.org/wiki/Hardware/Hollywood_GPIOs 20 * 21 * Note that for most registers, there are two versions: 22 * - HW_GPIOB_* Is always accessible by the Broadway PowerPC core, but does 23 * always give access to all GPIO lines 24 * - HW_GPIO_* Is only accessible by the Broadway PowerPC code if the memory 25 * firewall (AHBPROT) in the Hollywood chipset has been configured to allow 26 * such access. 27 * 28 * The ownership of each GPIO line can be configured in the HW_GPIO_OWNER 29 * register: A one bit configures the line for access via the HW_GPIOB_* 30 * registers, a zero bit indicates access via HW_GPIO_*. This driver uses 31 * HW_GPIOB_*. 32 */ 33 #define HW_GPIOB_OUT 0x00 34 #define HW_GPIOB_DIR 0x04 35 #define HW_GPIOB_IN 0x08 36 #define HW_GPIOB_INTLVL 0x0c 37 #define HW_GPIOB_INTFLAG 0x10 38 #define HW_GPIOB_INTMASK 0x14 39 #define HW_GPIOB_INMIR 0x18 40 #define HW_GPIO_ENABLE 0x1c 41 #define HW_GPIO_OUT 0x20 42 #define HW_GPIO_DIR 0x24 43 #define HW_GPIO_IN 0x28 44 #define HW_GPIO_INTLVL 0x2c 45 #define HW_GPIO_INTFLAG 0x30 46 #define HW_GPIO_INTMASK 0x34 47 #define HW_GPIO_INMIR 0x38 48 #define HW_GPIO_OWNER 0x3c 49 50 struct hlwd_gpio { 51 struct gpio_chip gpioc; 52 struct device *dev; 53 void __iomem *regs; 54 int irq; 55 u32 edge_emulation; 56 u32 rising_edge, falling_edge; 57 }; 58 59 static void hlwd_gpio_irqhandler(struct irq_desc *desc) 60 { 61 struct hlwd_gpio *hlwd = 62 gpiochip_get_data(irq_desc_get_handler_data(desc)); 63 struct irq_chip *chip = irq_desc_get_chip(desc); 64 unsigned long flags; 65 unsigned long pending; 66 int hwirq; 67 u32 emulated_pending; 68 69 raw_spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags); 70 pending = ioread32be(hlwd->regs + HW_GPIOB_INTFLAG); 71 pending &= ioread32be(hlwd->regs + HW_GPIOB_INTMASK); 72 73 /* Treat interrupts due to edge trigger emulation separately */ 74 emulated_pending = hlwd->edge_emulation & pending; 75 pending &= ~emulated_pending; 76 if (emulated_pending) { 77 u32 level, rising, falling; 78 79 level = ioread32be(hlwd->regs + HW_GPIOB_INTLVL); 80 rising = level & emulated_pending; 81 falling = ~level & emulated_pending; 82 83 /* Invert the levels */ 84 iowrite32be(level ^ emulated_pending, 85 hlwd->regs + HW_GPIOB_INTLVL); 86 87 /* Ack all emulated-edge interrupts */ 88 iowrite32be(emulated_pending, hlwd->regs + HW_GPIOB_INTFLAG); 89 90 /* Signal interrupts only on the correct edge */ 91 rising &= hlwd->rising_edge; 92 falling &= hlwd->falling_edge; 93 94 /* Mark emulated interrupts as pending */ 95 pending |= rising | falling; 96 } 97 raw_spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags); 98 99 chained_irq_enter(chip, desc); 100 101 for_each_set_bit(hwirq, &pending, 32) 102 generic_handle_domain_irq(hlwd->gpioc.irq.domain, hwirq); 103 104 chained_irq_exit(chip, desc); 105 } 106 107 static void hlwd_gpio_irq_ack(struct irq_data *data) 108 { 109 struct hlwd_gpio *hlwd = 110 gpiochip_get_data(irq_data_get_irq_chip_data(data)); 111 112 iowrite32be(BIT(data->hwirq), hlwd->regs + HW_GPIOB_INTFLAG); 113 } 114 115 static void hlwd_gpio_irq_mask(struct irq_data *data) 116 { 117 struct hlwd_gpio *hlwd = 118 gpiochip_get_data(irq_data_get_irq_chip_data(data)); 119 unsigned long flags; 120 u32 mask; 121 122 raw_spin_lock_irqsave(&hlwd->gpioc.bgpio_lock, flags); 123 mask = ioread32be(hlwd->regs + HW_GPIOB_INTMASK); 124 mask &= ~BIT(data->hwirq); 125 iowrite32be(mask, hlwd->regs + HW_GPIOB_INTMASK); 126 raw_spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags); 127 gpiochip_disable_irq(&hlwd->gpioc, irqd_to_hwirq(data)); 128 } 129 130 static void hlwd_gpio_irq_unmask(struct irq_data *data) 131 { 132 struct hlwd_gpio *hlwd = 133 gpiochip_get_data(irq_data_get_irq_chip_data(data)); 134 unsigned long flags; 135 u32 mask; 136 137 gpiochip_enable_irq(&hlwd->gpioc, irqd_to_hwirq(data)); 138 raw_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 raw_spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags); 143 } 144 145 static void hlwd_gpio_irq_enable(struct irq_data *data) 146 { 147 hlwd_gpio_irq_ack(data); 148 hlwd_gpio_irq_unmask(data); 149 } 150 151 static 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 } 171 172 static 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 raw_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 raw_spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags); 201 return -EINVAL; 202 } 203 204 raw_spin_unlock_irqrestore(&hlwd->gpioc.bgpio_lock, flags); 205 return 0; 206 } 207 208 static void hlwd_gpio_irq_print_chip(struct irq_data *data, struct seq_file *p) 209 { 210 struct hlwd_gpio *hlwd = 211 gpiochip_get_data(irq_data_get_irq_chip_data(data)); 212 213 seq_printf(p, dev_name(hlwd->dev)); 214 } 215 216 static const struct irq_chip hlwd_gpio_irq_chip = { 217 .irq_mask = hlwd_gpio_irq_mask, 218 .irq_unmask = hlwd_gpio_irq_unmask, 219 .irq_enable = hlwd_gpio_irq_enable, 220 .irq_set_type = hlwd_gpio_irq_set_type, 221 .irq_print_chip = hlwd_gpio_irq_print_chip, 222 .flags = IRQCHIP_IMMUTABLE, 223 GPIOCHIP_IRQ_RESOURCE_HELPERS, 224 }; 225 226 static int hlwd_gpio_probe(struct platform_device *pdev) 227 { 228 struct hlwd_gpio *hlwd; 229 u32 ngpios; 230 int res; 231 232 hlwd = devm_kzalloc(&pdev->dev, sizeof(*hlwd), GFP_KERNEL); 233 if (!hlwd) 234 return -ENOMEM; 235 236 hlwd->regs = devm_platform_ioremap_resource(pdev, 0); 237 if (IS_ERR(hlwd->regs)) 238 return PTR_ERR(hlwd->regs); 239 240 hlwd->dev = &pdev->dev; 241 242 /* 243 * Claim all GPIOs using the OWNER register. This will not work on 244 * systems where the AHBPROT memory firewall hasn't been configured to 245 * permit PPC access to HW_GPIO_*. 246 * 247 * Note that this has to happen before bgpio_init reads the 248 * HW_GPIOB_OUT and HW_GPIOB_DIR, because otherwise it reads the wrong 249 * values. 250 */ 251 iowrite32be(0xffffffff, hlwd->regs + HW_GPIO_OWNER); 252 253 res = bgpio_init(&hlwd->gpioc, &pdev->dev, 4, 254 hlwd->regs + HW_GPIOB_IN, hlwd->regs + HW_GPIOB_OUT, 255 NULL, hlwd->regs + HW_GPIOB_DIR, NULL, 256 BGPIOF_BIG_ENDIAN_BYTE_ORDER); 257 if (res < 0) { 258 dev_warn(&pdev->dev, "bgpio_init failed: %d\n", res); 259 return res; 260 } 261 262 res = of_property_read_u32(pdev->dev.of_node, "ngpios", &ngpios); 263 if (res) 264 ngpios = 32; 265 hlwd->gpioc.ngpio = ngpios; 266 267 /* Mask and ack all interrupts */ 268 iowrite32be(0, hlwd->regs + HW_GPIOB_INTMASK); 269 iowrite32be(0xffffffff, hlwd->regs + HW_GPIOB_INTFLAG); 270 271 /* 272 * If this GPIO controller is not marked as an interrupt controller in 273 * the DT, skip interrupt support. 274 */ 275 if (of_property_read_bool(pdev->dev.of_node, "interrupt-controller")) { 276 struct gpio_irq_chip *girq; 277 278 hlwd->irq = platform_get_irq(pdev, 0); 279 if (hlwd->irq < 0) { 280 dev_info(&pdev->dev, "platform_get_irq returned %d\n", 281 hlwd->irq); 282 return hlwd->irq; 283 } 284 285 girq = &hlwd->gpioc.irq; 286 gpio_irq_chip_set_chip(girq, &hlwd_gpio_irq_chip); 287 girq->parent_handler = hlwd_gpio_irqhandler; 288 girq->num_parents = 1; 289 girq->parents = devm_kcalloc(&pdev->dev, 1, 290 sizeof(*girq->parents), 291 GFP_KERNEL); 292 if (!girq->parents) 293 return -ENOMEM; 294 girq->parents[0] = hlwd->irq; 295 girq->default_type = IRQ_TYPE_NONE; 296 girq->handler = handle_level_irq; 297 } 298 299 return devm_gpiochip_add_data(&pdev->dev, &hlwd->gpioc, hlwd); 300 } 301 302 static const struct of_device_id hlwd_gpio_match[] = { 303 { .compatible = "nintendo,hollywood-gpio", }, 304 {}, 305 }; 306 MODULE_DEVICE_TABLE(of, hlwd_gpio_match); 307 308 static struct platform_driver hlwd_gpio_driver = { 309 .driver = { 310 .name = "gpio-hlwd", 311 .of_match_table = hlwd_gpio_match, 312 }, 313 .probe = hlwd_gpio_probe, 314 }; 315 module_platform_driver(hlwd_gpio_driver); 316 317 MODULE_AUTHOR("Jonathan Neuschäfer <j.neuschaefer@gmx.net>"); 318 MODULE_DESCRIPTION("Nintendo Wii GPIO driver"); 319 MODULE_LICENSE("GPL"); 320