1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * TQ-Systems TQMx86 PLD GPIO driver 4 * 5 * Based on vendor driver by: 6 * Vadim V.Vlasov <vvlasov@dev.rtsoft.ru> 7 */ 8 9 #include <linux/bitops.h> 10 #include <linux/errno.h> 11 #include <linux/gpio/driver.h> 12 #include <linux/init.h> 13 #include <linux/interrupt.h> 14 #include <linux/kernel.h> 15 #include <linux/module.h> 16 #include <linux/platform_device.h> 17 #include <linux/pm_runtime.h> 18 #include <linux/slab.h> 19 20 #define TQMX86_NGPIO 8 21 #define TQMX86_NGPO 4 /* 0-3 - output */ 22 #define TQMX86_NGPI 4 /* 4-7 - input */ 23 #define TQMX86_DIR_INPUT_MASK 0xf0 /* 0-3 - output, 4-7 - input */ 24 25 #define TQMX86_GPIODD 0 /* GPIO Data Direction Register */ 26 #define TQMX86_GPIOD 1 /* GPIO Data Register */ 27 #define TQMX86_GPIIC 3 /* GPI Interrupt Configuration Register */ 28 #define TQMX86_GPIIS 4 /* GPI Interrupt Status Register */ 29 30 #define TQMX86_GPII_FALLING BIT(0) 31 #define TQMX86_GPII_RISING BIT(1) 32 #define TQMX86_GPII_MASK (BIT(0) | BIT(1)) 33 #define TQMX86_GPII_BITS 2 34 35 struct tqmx86_gpio_data { 36 struct gpio_chip chip; 37 struct irq_chip irq_chip; 38 void __iomem *io_base; 39 int irq; 40 raw_spinlock_t spinlock; 41 u8 irq_type[TQMX86_NGPI]; 42 }; 43 44 static u8 tqmx86_gpio_read(struct tqmx86_gpio_data *gd, unsigned int reg) 45 { 46 return ioread8(gd->io_base + reg); 47 } 48 49 static void tqmx86_gpio_write(struct tqmx86_gpio_data *gd, u8 val, 50 unsigned int reg) 51 { 52 iowrite8(val, gd->io_base + reg); 53 } 54 55 static int tqmx86_gpio_get(struct gpio_chip *chip, unsigned int offset) 56 { 57 struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip); 58 59 return !!(tqmx86_gpio_read(gpio, TQMX86_GPIOD) & BIT(offset)); 60 } 61 62 static void tqmx86_gpio_set(struct gpio_chip *chip, unsigned int offset, 63 int value) 64 { 65 struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip); 66 unsigned long flags; 67 u8 val; 68 69 raw_spin_lock_irqsave(&gpio->spinlock, flags); 70 val = tqmx86_gpio_read(gpio, TQMX86_GPIOD); 71 if (value) 72 val |= BIT(offset); 73 else 74 val &= ~BIT(offset); 75 tqmx86_gpio_write(gpio, val, TQMX86_GPIOD); 76 raw_spin_unlock_irqrestore(&gpio->spinlock, flags); 77 } 78 79 static int tqmx86_gpio_direction_input(struct gpio_chip *chip, 80 unsigned int offset) 81 { 82 /* Direction cannot be changed. Validate is an input. */ 83 if (BIT(offset) & TQMX86_DIR_INPUT_MASK) 84 return 0; 85 else 86 return -EINVAL; 87 } 88 89 static int tqmx86_gpio_direction_output(struct gpio_chip *chip, 90 unsigned int offset, 91 int value) 92 { 93 /* Direction cannot be changed, validate is an output */ 94 if (BIT(offset) & TQMX86_DIR_INPUT_MASK) 95 return -EINVAL; 96 97 tqmx86_gpio_set(chip, offset, value); 98 return 0; 99 } 100 101 static int tqmx86_gpio_get_direction(struct gpio_chip *chip, 102 unsigned int offset) 103 { 104 if (TQMX86_DIR_INPUT_MASK & BIT(offset)) 105 return GPIO_LINE_DIRECTION_IN; 106 107 return GPIO_LINE_DIRECTION_OUT; 108 } 109 110 static void tqmx86_gpio_irq_mask(struct irq_data *data) 111 { 112 unsigned int offset = (data->hwirq - TQMX86_NGPO); 113 struct tqmx86_gpio_data *gpio = gpiochip_get_data( 114 irq_data_get_irq_chip_data(data)); 115 unsigned long flags; 116 u8 gpiic, mask; 117 118 mask = TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS); 119 120 raw_spin_lock_irqsave(&gpio->spinlock, flags); 121 gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC); 122 gpiic &= ~mask; 123 tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC); 124 raw_spin_unlock_irqrestore(&gpio->spinlock, flags); 125 } 126 127 static void tqmx86_gpio_irq_unmask(struct irq_data *data) 128 { 129 unsigned int offset = (data->hwirq - TQMX86_NGPO); 130 struct tqmx86_gpio_data *gpio = gpiochip_get_data( 131 irq_data_get_irq_chip_data(data)); 132 unsigned long flags; 133 u8 gpiic, mask; 134 135 mask = TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS); 136 137 raw_spin_lock_irqsave(&gpio->spinlock, flags); 138 gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC); 139 gpiic &= ~mask; 140 gpiic |= gpio->irq_type[offset] << (offset * TQMX86_GPII_BITS); 141 tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC); 142 raw_spin_unlock_irqrestore(&gpio->spinlock, flags); 143 } 144 145 static int tqmx86_gpio_irq_set_type(struct irq_data *data, unsigned int type) 146 { 147 struct tqmx86_gpio_data *gpio = gpiochip_get_data( 148 irq_data_get_irq_chip_data(data)); 149 unsigned int offset = (data->hwirq - TQMX86_NGPO); 150 unsigned int edge_type = type & IRQF_TRIGGER_MASK; 151 unsigned long flags; 152 u8 new_type, gpiic; 153 154 switch (edge_type) { 155 case IRQ_TYPE_EDGE_RISING: 156 new_type = TQMX86_GPII_RISING; 157 break; 158 case IRQ_TYPE_EDGE_FALLING: 159 new_type = TQMX86_GPII_FALLING; 160 break; 161 case IRQ_TYPE_EDGE_BOTH: 162 new_type = TQMX86_GPII_FALLING | TQMX86_GPII_RISING; 163 break; 164 default: 165 return -EINVAL; /* not supported */ 166 } 167 168 gpio->irq_type[offset] = new_type; 169 170 raw_spin_lock_irqsave(&gpio->spinlock, flags); 171 gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC); 172 gpiic &= ~((TQMX86_GPII_MASK) << (offset * TQMX86_GPII_BITS)); 173 gpiic |= new_type << (offset * TQMX86_GPII_BITS); 174 tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC); 175 raw_spin_unlock_irqrestore(&gpio->spinlock, flags); 176 177 return 0; 178 } 179 180 static void tqmx86_gpio_irq_handler(struct irq_desc *desc) 181 { 182 struct gpio_chip *chip = irq_desc_get_handler_data(desc); 183 struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip); 184 struct irq_chip *irq_chip = irq_desc_get_chip(desc); 185 unsigned long irq_bits; 186 int i = 0; 187 u8 irq_status; 188 189 chained_irq_enter(irq_chip, desc); 190 191 irq_status = tqmx86_gpio_read(gpio, TQMX86_GPIIS); 192 tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS); 193 194 irq_bits = irq_status; 195 for_each_set_bit(i, &irq_bits, TQMX86_NGPI) 196 generic_handle_domain_irq(gpio->chip.irq.domain, 197 i + TQMX86_NGPO); 198 199 chained_irq_exit(irq_chip, desc); 200 } 201 202 /* Minimal runtime PM is needed by the IRQ subsystem */ 203 static int __maybe_unused tqmx86_gpio_runtime_suspend(struct device *dev) 204 { 205 return 0; 206 } 207 208 static int __maybe_unused tqmx86_gpio_runtime_resume(struct device *dev) 209 { 210 return 0; 211 } 212 213 static const struct dev_pm_ops tqmx86_gpio_dev_pm_ops = { 214 SET_RUNTIME_PM_OPS(tqmx86_gpio_runtime_suspend, 215 tqmx86_gpio_runtime_resume, NULL) 216 }; 217 218 static void tqmx86_init_irq_valid_mask(struct gpio_chip *chip, 219 unsigned long *valid_mask, 220 unsigned int ngpios) 221 { 222 /* Only GPIOs 4-7 are valid for interrupts. Clear the others */ 223 clear_bit(0, valid_mask); 224 clear_bit(1, valid_mask); 225 clear_bit(2, valid_mask); 226 clear_bit(3, valid_mask); 227 } 228 229 static int tqmx86_gpio_probe(struct platform_device *pdev) 230 { 231 struct device *dev = &pdev->dev; 232 struct tqmx86_gpio_data *gpio; 233 struct gpio_chip *chip; 234 struct gpio_irq_chip *girq; 235 void __iomem *io_base; 236 struct resource *res; 237 int ret, irq; 238 239 irq = platform_get_irq_optional(pdev, 0); 240 if (irq < 0 && irq != -ENXIO) 241 return irq; 242 243 res = platform_get_resource(pdev, IORESOURCE_IO, 0); 244 if (!res) { 245 dev_err(&pdev->dev, "Cannot get I/O\n"); 246 return -ENODEV; 247 } 248 249 io_base = devm_ioport_map(&pdev->dev, res->start, resource_size(res)); 250 if (!io_base) 251 return -ENOMEM; 252 253 gpio = devm_kzalloc(dev, sizeof(*gpio), GFP_KERNEL); 254 if (!gpio) 255 return -ENOMEM; 256 257 raw_spin_lock_init(&gpio->spinlock); 258 gpio->io_base = io_base; 259 260 tqmx86_gpio_write(gpio, (u8)~TQMX86_DIR_INPUT_MASK, TQMX86_GPIODD); 261 262 platform_set_drvdata(pdev, gpio); 263 264 chip = &gpio->chip; 265 chip->label = "gpio-tqmx86"; 266 chip->owner = THIS_MODULE; 267 chip->can_sleep = false; 268 chip->base = -1; 269 chip->direction_input = tqmx86_gpio_direction_input; 270 chip->direction_output = tqmx86_gpio_direction_output; 271 chip->get_direction = tqmx86_gpio_get_direction; 272 chip->get = tqmx86_gpio_get; 273 chip->set = tqmx86_gpio_set; 274 chip->ngpio = TQMX86_NGPIO; 275 chip->parent = pdev->dev.parent; 276 277 pm_runtime_enable(&pdev->dev); 278 279 if (irq > 0) { 280 struct irq_chip *irq_chip = &gpio->irq_chip; 281 u8 irq_status; 282 283 irq_chip->name = chip->label; 284 irq_chip->parent_device = &pdev->dev; 285 irq_chip->irq_mask = tqmx86_gpio_irq_mask; 286 irq_chip->irq_unmask = tqmx86_gpio_irq_unmask; 287 irq_chip->irq_set_type = tqmx86_gpio_irq_set_type; 288 289 /* Mask all interrupts */ 290 tqmx86_gpio_write(gpio, 0, TQMX86_GPIIC); 291 292 /* Clear all pending interrupts */ 293 irq_status = tqmx86_gpio_read(gpio, TQMX86_GPIIS); 294 tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS); 295 296 girq = &chip->irq; 297 girq->chip = irq_chip; 298 girq->parent_handler = tqmx86_gpio_irq_handler; 299 girq->num_parents = 1; 300 girq->parents = devm_kcalloc(&pdev->dev, 1, 301 sizeof(*girq->parents), 302 GFP_KERNEL); 303 if (!girq->parents) { 304 ret = -ENOMEM; 305 goto out_pm_dis; 306 } 307 girq->parents[0] = irq; 308 girq->default_type = IRQ_TYPE_NONE; 309 girq->handler = handle_simple_irq; 310 girq->init_valid_mask = tqmx86_init_irq_valid_mask; 311 } 312 313 ret = devm_gpiochip_add_data(dev, chip, gpio); 314 if (ret) { 315 dev_err(dev, "Could not register GPIO chip\n"); 316 goto out_pm_dis; 317 } 318 319 dev_info(dev, "GPIO functionality initialized with %d pins\n", 320 chip->ngpio); 321 322 return 0; 323 324 out_pm_dis: 325 pm_runtime_disable(&pdev->dev); 326 327 return ret; 328 } 329 330 static struct platform_driver tqmx86_gpio_driver = { 331 .driver = { 332 .name = "tqmx86-gpio", 333 .pm = &tqmx86_gpio_dev_pm_ops, 334 }, 335 .probe = tqmx86_gpio_probe, 336 }; 337 338 module_platform_driver(tqmx86_gpio_driver); 339 340 MODULE_DESCRIPTION("TQMx86 PLD GPIO Driver"); 341 MODULE_AUTHOR("Andrew Lunn <andrew@lunn.ch>"); 342 MODULE_LICENSE("GPL"); 343 MODULE_ALIAS("platform:tqmx86-gpio"); 344