1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Timberdale FPGA GPIO driver 4 * Author: Mocean Laboratories 5 * Copyright (c) 2009 Intel Corporation 6 */ 7 8 /* Supports: 9 * Timberdale FPGA GPIO 10 */ 11 12 #include <linux/init.h> 13 #include <linux/gpio/driver.h> 14 #include <linux/platform_device.h> 15 #include <linux/irq.h> 16 #include <linux/io.h> 17 #include <linux/timb_gpio.h> 18 #include <linux/interrupt.h> 19 #include <linux/slab.h> 20 21 #define DRIVER_NAME "timb-gpio" 22 23 #define TGPIOVAL 0x00 24 #define TGPIODIR 0x04 25 #define TGPIO_IER 0x08 26 #define TGPIO_ISR 0x0c 27 #define TGPIO_IPR 0x10 28 #define TGPIO_ICR 0x14 29 #define TGPIO_FLR 0x18 30 #define TGPIO_LVR 0x1c 31 #define TGPIO_VER 0x20 32 #define TGPIO_BFLR 0x24 33 34 struct timbgpio { 35 void __iomem *membase; 36 spinlock_t lock; /* mutual exclusion */ 37 struct gpio_chip gpio; 38 int irq_base; 39 unsigned long last_ier; 40 }; 41 42 static int timbgpio_update_bit(struct gpio_chip *gpio, unsigned index, 43 unsigned offset, bool enabled) 44 { 45 struct timbgpio *tgpio = gpiochip_get_data(gpio); 46 unsigned long flags; 47 u32 reg; 48 49 spin_lock_irqsave(&tgpio->lock, flags); 50 reg = ioread32(tgpio->membase + offset); 51 52 if (enabled) 53 reg |= (1 << index); 54 else 55 reg &= ~(1 << index); 56 57 iowrite32(reg, tgpio->membase + offset); 58 spin_unlock_irqrestore(&tgpio->lock, flags); 59 60 return 0; 61 } 62 63 static int timbgpio_gpio_direction_input(struct gpio_chip *gpio, unsigned nr) 64 { 65 return timbgpio_update_bit(gpio, nr, TGPIODIR, true); 66 } 67 68 static int timbgpio_gpio_get(struct gpio_chip *gpio, unsigned nr) 69 { 70 struct timbgpio *tgpio = gpiochip_get_data(gpio); 71 u32 value; 72 73 value = ioread32(tgpio->membase + TGPIOVAL); 74 return (value & (1 << nr)) ? 1 : 0; 75 } 76 77 static int timbgpio_gpio_direction_output(struct gpio_chip *gpio, 78 unsigned nr, int val) 79 { 80 return timbgpio_update_bit(gpio, nr, TGPIODIR, false); 81 } 82 83 static void timbgpio_gpio_set(struct gpio_chip *gpio, 84 unsigned nr, int val) 85 { 86 timbgpio_update_bit(gpio, nr, TGPIOVAL, val != 0); 87 } 88 89 static int timbgpio_to_irq(struct gpio_chip *gpio, unsigned offset) 90 { 91 struct timbgpio *tgpio = gpiochip_get_data(gpio); 92 93 if (tgpio->irq_base <= 0) 94 return -EINVAL; 95 96 return tgpio->irq_base + offset; 97 } 98 99 /* 100 * GPIO IRQ 101 */ 102 static void timbgpio_irq_disable(struct irq_data *d) 103 { 104 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d); 105 int offset = d->irq - tgpio->irq_base; 106 unsigned long flags; 107 108 spin_lock_irqsave(&tgpio->lock, flags); 109 tgpio->last_ier &= ~(1UL << offset); 110 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER); 111 spin_unlock_irqrestore(&tgpio->lock, flags); 112 } 113 114 static void timbgpio_irq_enable(struct irq_data *d) 115 { 116 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d); 117 int offset = d->irq - tgpio->irq_base; 118 unsigned long flags; 119 120 spin_lock_irqsave(&tgpio->lock, flags); 121 tgpio->last_ier |= 1UL << offset; 122 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER); 123 spin_unlock_irqrestore(&tgpio->lock, flags); 124 } 125 126 static int timbgpio_irq_type(struct irq_data *d, unsigned trigger) 127 { 128 struct timbgpio *tgpio = irq_data_get_irq_chip_data(d); 129 int offset = d->irq - tgpio->irq_base; 130 unsigned long flags; 131 u32 lvr, flr, bflr = 0; 132 u32 ver; 133 int ret = 0; 134 135 if (offset < 0 || offset > tgpio->gpio.ngpio) 136 return -EINVAL; 137 138 ver = ioread32(tgpio->membase + TGPIO_VER); 139 140 spin_lock_irqsave(&tgpio->lock, flags); 141 142 lvr = ioread32(tgpio->membase + TGPIO_LVR); 143 flr = ioread32(tgpio->membase + TGPIO_FLR); 144 if (ver > 2) 145 bflr = ioread32(tgpio->membase + TGPIO_BFLR); 146 147 if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) { 148 bflr &= ~(1 << offset); 149 flr &= ~(1 << offset); 150 if (trigger & IRQ_TYPE_LEVEL_HIGH) 151 lvr |= 1 << offset; 152 else 153 lvr &= ~(1 << offset); 154 } 155 156 if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) { 157 if (ver < 3) { 158 ret = -EINVAL; 159 goto out; 160 } else { 161 flr |= 1 << offset; 162 bflr |= 1 << offset; 163 } 164 } else { 165 bflr &= ~(1 << offset); 166 flr |= 1 << offset; 167 if (trigger & IRQ_TYPE_EDGE_FALLING) 168 lvr &= ~(1 << offset); 169 else 170 lvr |= 1 << offset; 171 } 172 173 iowrite32(lvr, tgpio->membase + TGPIO_LVR); 174 iowrite32(flr, tgpio->membase + TGPIO_FLR); 175 if (ver > 2) 176 iowrite32(bflr, tgpio->membase + TGPIO_BFLR); 177 178 iowrite32(1 << offset, tgpio->membase + TGPIO_ICR); 179 180 out: 181 spin_unlock_irqrestore(&tgpio->lock, flags); 182 return ret; 183 } 184 185 static void timbgpio_irq(struct irq_desc *desc) 186 { 187 struct timbgpio *tgpio = irq_desc_get_handler_data(desc); 188 struct irq_data *data = irq_desc_get_irq_data(desc); 189 unsigned long ipr; 190 int offset; 191 192 data->chip->irq_ack(data); 193 ipr = ioread32(tgpio->membase + TGPIO_IPR); 194 iowrite32(ipr, tgpio->membase + TGPIO_ICR); 195 196 /* 197 * Some versions of the hardware trash the IER register if more than 198 * one interrupt is received simultaneously. 199 */ 200 iowrite32(0, tgpio->membase + TGPIO_IER); 201 202 for_each_set_bit(offset, &ipr, tgpio->gpio.ngpio) 203 generic_handle_irq(timbgpio_to_irq(&tgpio->gpio, offset)); 204 205 iowrite32(tgpio->last_ier, tgpio->membase + TGPIO_IER); 206 } 207 208 static struct irq_chip timbgpio_irqchip = { 209 .name = "GPIO", 210 .irq_enable = timbgpio_irq_enable, 211 .irq_disable = timbgpio_irq_disable, 212 .irq_set_type = timbgpio_irq_type, 213 }; 214 215 static int timbgpio_probe(struct platform_device *pdev) 216 { 217 int err, i; 218 struct device *dev = &pdev->dev; 219 struct gpio_chip *gc; 220 struct timbgpio *tgpio; 221 struct timbgpio_platform_data *pdata = dev_get_platdata(&pdev->dev); 222 int irq = platform_get_irq(pdev, 0); 223 224 if (!pdata || pdata->nr_pins > 32) { 225 dev_err(dev, "Invalid platform data\n"); 226 return -EINVAL; 227 } 228 229 tgpio = devm_kzalloc(dev, sizeof(*tgpio), GFP_KERNEL); 230 if (!tgpio) 231 return -EINVAL; 232 233 tgpio->irq_base = pdata->irq_base; 234 235 spin_lock_init(&tgpio->lock); 236 237 tgpio->membase = devm_platform_ioremap_resource(pdev, 0); 238 if (IS_ERR(tgpio->membase)) 239 return PTR_ERR(tgpio->membase); 240 241 gc = &tgpio->gpio; 242 243 gc->label = dev_name(&pdev->dev); 244 gc->owner = THIS_MODULE; 245 gc->parent = &pdev->dev; 246 gc->direction_input = timbgpio_gpio_direction_input; 247 gc->get = timbgpio_gpio_get; 248 gc->direction_output = timbgpio_gpio_direction_output; 249 gc->set = timbgpio_gpio_set; 250 gc->to_irq = (irq >= 0 && tgpio->irq_base > 0) ? timbgpio_to_irq : NULL; 251 gc->dbg_show = NULL; 252 gc->base = pdata->gpio_base; 253 gc->ngpio = pdata->nr_pins; 254 gc->can_sleep = false; 255 256 err = devm_gpiochip_add_data(&pdev->dev, gc, tgpio); 257 if (err) 258 return err; 259 260 /* make sure to disable interrupts */ 261 iowrite32(0x0, tgpio->membase + TGPIO_IER); 262 263 if (irq < 0 || tgpio->irq_base <= 0) 264 return 0; 265 266 for (i = 0; i < pdata->nr_pins; i++) { 267 irq_set_chip_and_handler(tgpio->irq_base + i, 268 &timbgpio_irqchip, handle_simple_irq); 269 irq_set_chip_data(tgpio->irq_base + i, tgpio); 270 irq_clear_status_flags(tgpio->irq_base + i, IRQ_NOREQUEST | IRQ_NOPROBE); 271 } 272 273 irq_set_chained_handler_and_data(irq, timbgpio_irq, tgpio); 274 275 return 0; 276 } 277 278 static struct platform_driver timbgpio_platform_driver = { 279 .driver = { 280 .name = DRIVER_NAME, 281 .suppress_bind_attrs = true, 282 }, 283 .probe = timbgpio_probe, 284 }; 285 286 /*--------------------------------------------------------------------------*/ 287 288 builtin_platform_driver(timbgpio_platform_driver); 289