1 /* 2 * Atheros AR71XX/AR724X/AR913X GPIO API support 3 * 4 * Copyright (C) 2015 Alban Bedel <albeu@free.fr> 5 * Copyright (C) 2010-2011 Jaiganesh Narayanan <jnarayanan@atheros.com> 6 * Copyright (C) 2008-2011 Gabor Juhos <juhosg@openwrt.org> 7 * Copyright (C) 2008 Imre Kaloz <kaloz@openwrt.org> 8 * 9 * This program is free software; you can redistribute it and/or modify it 10 * under the terms of the GNU General Public License version 2 as published 11 * by the Free Software Foundation. 12 */ 13 14 #include <linux/gpio/driver.h> 15 #include <linux/platform_data/gpio-ath79.h> 16 #include <linux/of_device.h> 17 #include <linux/interrupt.h> 18 #include <linux/module.h> 19 #include <linux/irq.h> 20 21 #define AR71XX_GPIO_REG_OE 0x00 22 #define AR71XX_GPIO_REG_IN 0x04 23 #define AR71XX_GPIO_REG_SET 0x0c 24 #define AR71XX_GPIO_REG_CLEAR 0x10 25 26 #define AR71XX_GPIO_REG_INT_ENABLE 0x14 27 #define AR71XX_GPIO_REG_INT_TYPE 0x18 28 #define AR71XX_GPIO_REG_INT_POLARITY 0x1c 29 #define AR71XX_GPIO_REG_INT_PENDING 0x20 30 #define AR71XX_GPIO_REG_INT_MASK 0x24 31 32 struct ath79_gpio_ctrl { 33 struct gpio_chip gc; 34 void __iomem *base; 35 spinlock_t lock; 36 unsigned long both_edges; 37 }; 38 39 static struct ath79_gpio_ctrl *irq_data_to_ath79_gpio(struct irq_data *data) 40 { 41 struct gpio_chip *gc = irq_data_get_irq_chip_data(data); 42 43 return container_of(gc, struct ath79_gpio_ctrl, gc); 44 } 45 46 static u32 ath79_gpio_read(struct ath79_gpio_ctrl *ctrl, unsigned reg) 47 { 48 return readl(ctrl->base + reg); 49 } 50 51 static void ath79_gpio_write(struct ath79_gpio_ctrl *ctrl, 52 unsigned reg, u32 val) 53 { 54 return writel(val, ctrl->base + reg); 55 } 56 57 static bool ath79_gpio_update_bits( 58 struct ath79_gpio_ctrl *ctrl, unsigned reg, u32 mask, u32 bits) 59 { 60 u32 old_val, new_val; 61 62 old_val = ath79_gpio_read(ctrl, reg); 63 new_val = (old_val & ~mask) | (bits & mask); 64 65 if (new_val != old_val) 66 ath79_gpio_write(ctrl, reg, new_val); 67 68 return new_val != old_val; 69 } 70 71 static void ath79_gpio_irq_unmask(struct irq_data *data) 72 { 73 struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data); 74 u32 mask = BIT(irqd_to_hwirq(data)); 75 unsigned long flags; 76 77 spin_lock_irqsave(&ctrl->lock, flags); 78 ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask); 79 spin_unlock_irqrestore(&ctrl->lock, flags); 80 } 81 82 static void ath79_gpio_irq_mask(struct irq_data *data) 83 { 84 struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data); 85 u32 mask = BIT(irqd_to_hwirq(data)); 86 unsigned long flags; 87 88 spin_lock_irqsave(&ctrl->lock, flags); 89 ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0); 90 spin_unlock_irqrestore(&ctrl->lock, flags); 91 } 92 93 static void ath79_gpio_irq_enable(struct irq_data *data) 94 { 95 struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data); 96 u32 mask = BIT(irqd_to_hwirq(data)); 97 unsigned long flags; 98 99 spin_lock_irqsave(&ctrl->lock, flags); 100 ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask); 101 ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, mask); 102 spin_unlock_irqrestore(&ctrl->lock, flags); 103 } 104 105 static void ath79_gpio_irq_disable(struct irq_data *data) 106 { 107 struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data); 108 u32 mask = BIT(irqd_to_hwirq(data)); 109 unsigned long flags; 110 111 spin_lock_irqsave(&ctrl->lock, flags); 112 ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_MASK, mask, 0); 113 ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0); 114 spin_unlock_irqrestore(&ctrl->lock, flags); 115 } 116 117 static int ath79_gpio_irq_set_type(struct irq_data *data, 118 unsigned int flow_type) 119 { 120 struct ath79_gpio_ctrl *ctrl = irq_data_to_ath79_gpio(data); 121 u32 mask = BIT(irqd_to_hwirq(data)); 122 u32 type = 0, polarity = 0; 123 unsigned long flags; 124 bool disabled; 125 126 switch (flow_type) { 127 case IRQ_TYPE_EDGE_RISING: 128 polarity |= mask; 129 case IRQ_TYPE_EDGE_FALLING: 130 case IRQ_TYPE_EDGE_BOTH: 131 break; 132 133 case IRQ_TYPE_LEVEL_HIGH: 134 polarity |= mask; 135 case IRQ_TYPE_LEVEL_LOW: 136 type |= mask; 137 break; 138 139 default: 140 return -EINVAL; 141 } 142 143 spin_lock_irqsave(&ctrl->lock, flags); 144 145 if (flow_type == IRQ_TYPE_EDGE_BOTH) { 146 ctrl->both_edges |= mask; 147 polarity = ~ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN); 148 } else { 149 ctrl->both_edges &= ~mask; 150 } 151 152 /* As the IRQ configuration can't be loaded atomically we 153 * have to disable the interrupt while the configuration state 154 * is invalid. 155 */ 156 disabled = ath79_gpio_update_bits( 157 ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, 0); 158 159 ath79_gpio_update_bits( 160 ctrl, AR71XX_GPIO_REG_INT_TYPE, mask, type); 161 ath79_gpio_update_bits( 162 ctrl, AR71XX_GPIO_REG_INT_POLARITY, mask, polarity); 163 164 if (disabled) 165 ath79_gpio_update_bits( 166 ctrl, AR71XX_GPIO_REG_INT_ENABLE, mask, mask); 167 168 spin_unlock_irqrestore(&ctrl->lock, flags); 169 170 return 0; 171 } 172 173 static struct irq_chip ath79_gpio_irqchip = { 174 .name = "gpio-ath79", 175 .irq_enable = ath79_gpio_irq_enable, 176 .irq_disable = ath79_gpio_irq_disable, 177 .irq_mask = ath79_gpio_irq_mask, 178 .irq_unmask = ath79_gpio_irq_unmask, 179 .irq_set_type = ath79_gpio_irq_set_type, 180 }; 181 182 static void ath79_gpio_irq_handler(struct irq_desc *desc) 183 { 184 struct gpio_chip *gc = irq_desc_get_handler_data(desc); 185 struct irq_chip *irqchip = irq_desc_get_chip(desc); 186 struct ath79_gpio_ctrl *ctrl = 187 container_of(gc, struct ath79_gpio_ctrl, gc); 188 unsigned long flags, pending; 189 u32 both_edges, state; 190 int irq; 191 192 chained_irq_enter(irqchip, desc); 193 194 spin_lock_irqsave(&ctrl->lock, flags); 195 196 pending = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_INT_PENDING); 197 198 /* Update the polarity of the both edges irqs */ 199 both_edges = ctrl->both_edges & pending; 200 if (both_edges) { 201 state = ath79_gpio_read(ctrl, AR71XX_GPIO_REG_IN); 202 ath79_gpio_update_bits(ctrl, AR71XX_GPIO_REG_INT_POLARITY, 203 both_edges, ~state); 204 } 205 206 spin_unlock_irqrestore(&ctrl->lock, flags); 207 208 if (pending) { 209 for_each_set_bit(irq, &pending, gc->ngpio) 210 generic_handle_irq( 211 irq_linear_revmap(gc->irqdomain, irq)); 212 } 213 214 chained_irq_exit(irqchip, desc); 215 } 216 217 static const struct of_device_id ath79_gpio_of_match[] = { 218 { .compatible = "qca,ar7100-gpio" }, 219 { .compatible = "qca,ar9340-gpio" }, 220 {}, 221 }; 222 223 static int ath79_gpio_probe(struct platform_device *pdev) 224 { 225 struct ath79_gpio_platform_data *pdata = dev_get_platdata(&pdev->dev); 226 struct device_node *np = pdev->dev.of_node; 227 struct ath79_gpio_ctrl *ctrl; 228 struct resource *res; 229 u32 ath79_gpio_count; 230 bool oe_inverted; 231 int err; 232 233 ctrl = devm_kzalloc(&pdev->dev, sizeof(*ctrl), GFP_KERNEL); 234 if (!ctrl) 235 return -ENOMEM; 236 platform_set_drvdata(pdev, ctrl); 237 238 if (np) { 239 err = of_property_read_u32(np, "ngpios", &ath79_gpio_count); 240 if (err) { 241 dev_err(&pdev->dev, "ngpios property is not valid\n"); 242 return err; 243 } 244 oe_inverted = of_device_is_compatible(np, "qca,ar9340-gpio"); 245 } else if (pdata) { 246 ath79_gpio_count = pdata->ngpios; 247 oe_inverted = pdata->oe_inverted; 248 } else { 249 dev_err(&pdev->dev, "No DT node or platform data found\n"); 250 return -EINVAL; 251 } 252 253 if (ath79_gpio_count >= 32) { 254 dev_err(&pdev->dev, "ngpios must be less than 32\n"); 255 return -EINVAL; 256 } 257 258 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 259 ctrl->base = devm_ioremap_nocache( 260 &pdev->dev, res->start, resource_size(res)); 261 if (!ctrl->base) 262 return -ENOMEM; 263 264 spin_lock_init(&ctrl->lock); 265 err = bgpio_init(&ctrl->gc, &pdev->dev, 4, 266 ctrl->base + AR71XX_GPIO_REG_IN, 267 ctrl->base + AR71XX_GPIO_REG_SET, 268 ctrl->base + AR71XX_GPIO_REG_CLEAR, 269 oe_inverted ? NULL : ctrl->base + AR71XX_GPIO_REG_OE, 270 oe_inverted ? ctrl->base + AR71XX_GPIO_REG_OE : NULL, 271 0); 272 if (err) { 273 dev_err(&pdev->dev, "bgpio_init failed\n"); 274 return err; 275 } 276 /* Use base 0 to stay compatible with legacy platforms */ 277 ctrl->gc.base = 0; 278 279 err = gpiochip_add_data(&ctrl->gc, ctrl); 280 if (err) { 281 dev_err(&pdev->dev, 282 "cannot add AR71xx GPIO chip, error=%d", err); 283 return err; 284 } 285 286 if (np && !of_property_read_bool(np, "interrupt-controller")) 287 return 0; 288 289 err = gpiochip_irqchip_add(&ctrl->gc, &ath79_gpio_irqchip, 0, 290 handle_simple_irq, IRQ_TYPE_NONE); 291 if (err) { 292 dev_err(&pdev->dev, "failed to add gpiochip_irqchip\n"); 293 goto gpiochip_remove; 294 } 295 296 gpiochip_set_chained_irqchip(&ctrl->gc, &ath79_gpio_irqchip, 297 platform_get_irq(pdev, 0), 298 ath79_gpio_irq_handler); 299 300 return 0; 301 302 gpiochip_remove: 303 gpiochip_remove(&ctrl->gc); 304 return err; 305 } 306 307 static int ath79_gpio_remove(struct platform_device *pdev) 308 { 309 struct ath79_gpio_ctrl *ctrl = platform_get_drvdata(pdev); 310 311 gpiochip_remove(&ctrl->gc); 312 return 0; 313 } 314 315 static struct platform_driver ath79_gpio_driver = { 316 .driver = { 317 .name = "ath79-gpio", 318 .of_match_table = ath79_gpio_of_match, 319 }, 320 .probe = ath79_gpio_probe, 321 .remove = ath79_gpio_remove, 322 }; 323 324 module_platform_driver(ath79_gpio_driver); 325