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